@inproceedings{Kholtygin2007, author = {Kholtygin, A. F.}, title = {Wavelets for looking for clumping in the wind of OB stars}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17796}, year = {2007}, abstract = {Clumping in hot-star winds : proceedings of an international workshop held in Potsdam, Germany, 18. - 22. June 2007}, language = {en} } @inproceedings{UrbanejaKudritzkiPuls2007, author = {Urbaneja, M. A. and Kudritzki, R.-P. and Puls, Joachim}, title = {Clumping in the winds of O-type CSPNs}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17801}, year = {2007}, abstract = {Recent studies of massive O-type stars present clear evidences of inhomogeneous and clumped winds. O-type (H-rich) central stars of planetary nebulae (CSPNs) are in some ways the low mass-low luminosity analogous of those massive stars. In this contribution, we present preliminary results of our on-going multi-wavelength (FUV, UV and optical) study of the winds of Galactic CSPNs. Particular emphasis will be given to the clumping factors derived by means of optical lines (Hα and Heii 4686) and "classic" FUV (and UV) lines.}, language = {en} } @inproceedings{deKoterVinkMuijres2007, author = {de Koter, A. and Vink, J. S. and Muijres, L.}, title = {Constraints on wind clumping from the empirical mass-loss vs. metallicity relation for early-type stars}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17736}, year = {2007}, abstract = {We present the latest results on the observational dependence of the mass-loss rate in stellar winds of O and early-B stars on the metal content of their atmospheres, and compare these with predictions. Absolute empirical rates for the mass loss of stars brighter than 10\$^{5.2} L_{\odot}\$, based on H\$\alpha\$ and ultraviolet (UV) wind lines, are found to be about a factor of two higher than predictions. If this difference is attributed to inhomogeneities in the wind this would imply that luminous O and early-B stars have clumping factors in their H\$\alpha\$ and UV line forming regime of about a factor of 3--5. The investigated stars cover a metallicity range \$Z\$ from 0.2 to 1 \$Z_{\odot}\$. We find a hint towards smaller clumping factors for lower \$Z\$. The derived clumping factors, however, presuppose that clumping does not impact the predictions of the mass-loss rate. We discuss this assumption and explain how we intend to investigate its validity in more detail.}, language = {en} } @inproceedings{ReyesIturbideVelazquezRosado2007, author = {Reyes-Iturbide, J. and Vel{\´a}zquez, P. and Rosado, M.}, title = {3D numerical model for an asymmetrical superbubble}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17724}, year = {2007}, abstract = {Massive stars usually form groups such as OB associations. Their fast stellar winds sweep up collectively the surrounding insterstellar medium (ISM) to generate superbubbles. Observations suggest that superbubble evolution on the surrounding ISM can be very irregular. Numerical simulations considering these conditions could help to understand the evolution of these superbubbles and to clarify the dynamics of these objects as well as the difference between observed X-ray luminosities and the predicted ones by the standard model (Weaver et al. 1977).}, language = {en} } @inproceedings{GrohHillierDamineli2007, author = {Groh, J. H. and Hillier, D. J. and Damineli, A.}, title = {Mass-loss rate and clumping in LBV stars : the impact of time-dependent effects}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17773}, year = {2007}, abstract = {This paper outlines a newly-developed method to include the effects of time variability in the radiative transfer code CMFGEN. It is shown that the flow timescale is often large compared to the variability timescale of LBVs. Thus, time-dependent effects significantly change the velocity law and density structure of the wind, affecting the derivation of the mass-loss rate, volume filling factor, wind terminal velocity, and luminosity. The results of this work are directly applicable to all active LBVs in the Galaxy and in the LMC, such as AG Car, HR Car, S Dor and R 127, and could result in a revision of stellar and wind parameters. The massloss rate evolution of AG Car during the last 20 years is presented, highlighting the need for time-dependent models to correctly interpret the evolution of LBVs.}, language = {en} } @misc{HowaldElsenbeerLaczkoetal.1995, author = {Howald, Markus and Elsenbeer, Helmut and Laczko, Endre and Schlunegger, Urs Peter}, title = {Capillary electrophoresis as a fast and universal tool in soil analysis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16913}, year = {1995}, abstract = {Fast analysis of different species of molecules in soils is investigated by capillary electrophoresis (CE). Several CE techniques for the analysis of inorganic ions and carbohydrates have been tested. With regard to the intents of pedologists and the usually large number of soil analyses a bundle of CE systems is proposed, capable of effecting time-saving soil analyses. Adapted electrolyte systems recently published and new separation systems are described. Examples of the application of these methods to two different soil samples are presented.}, language = {en} } @article{Kitagawa2007, author = {Kitagawa, Yoshihisa}, title = {When we fail to question in Japanese}, series = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, volume = {9}, journal = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, editor = {Ishihara, Shinichiro and Petrova, Svetlana and Schwarz, Anne}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-4725}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-24481}, pages = {29 -- 64}, year = {2007}, abstract = {When we pay close attention to the prosody of Wh-questions in Japanese, we discover many novel and interesting empirical puzzles that would require us to devise a much finer syntactic component of grammar. This paper addresses the issues that pose some problems to such an elaborated grammar, and offers solutions, making an appeal to the information structure and sentence processing involved in the interpretation of interrogative and focus constructions.}, language = {en} } @article{Mitchell2000, author = {Mitchell, Don}, title = {The end of culture?}, series = {Geographische Revue : Zeitschrift f{\"u}r Literatur und Diskussion}, volume = {2}, journal = {Geographische Revue : Zeitschrift f{\"u}r Literatur und Diskussion}, number = {2}, issn = {1438-3039}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-24016}, pages = {3 -- 17}, year = {2000}, abstract = {Content: -"Post-Culture" -Cultural Studies, Geography, and Culturalism -Taking Culture Seriously in the Post-Cultural World -Conclusion}, language = {en} } @article{Smith2001, author = {Smith, Neil}, title = {Marxism and Geography in the Anglophone World}, series = {Geographische Revue : Zeitschrift f{\"u}r Literatur und Diskussion}, volume = {3}, journal = {Geographische Revue : Zeitschrift f{\"u}r Literatur und Diskussion}, number = {2}, issn = {1438-3039}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-24357}, pages = {5 -- 21}, year = {2001}, abstract = {Content: Activism: The Origins of Marxism in English-language Geography After the Revolution: Critique, Institutionalization and Backlash Marxist Geography Today: Scale, Labour Geography, Activism Conclusion}, language = {en} } @phdthesis{Hoffmann2007, author = {Hoffmann, Toni}, title = {Cloning and characterisation of the HMA3 gene and its promoter from Arabidopsis halleri (L.) O'Kane and Al'Shehbaz and Arabidopsis thaliana (L.) Heynhold}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15259}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Being living systems unable to adjust their location to changing environmental conditions, plants display homeostatic networks that have evolved to maintain transition metal levels in a very narrow concentration range in order to avoid either deficiency or toxicity. Hence, plants possess a broad repertoire of mechanisms for the cellular uptake, compartmentation and efflux, as well as for the chelation of transition metal ions. A small number of plants are hypertolerant to one or a few specific transition metals. Some metal tolerant plants are also able to hyperaccumulate metal ions. The Brassicaceae family member Arabidopis halleri ssp. halleri (L.) O´KANE and AL´SHEHBAZ is a hyperaccumulator of zinc (Zn), and it is closely related to the non-hypertolerant and non-hyperaccumulating model plant Arabidopsis thaliana (L.) HEYNHOLD. The close relationship renders A. halleri a promising emerging model plant for the comparative investigation of the molecular mechanisms behind hypertolerance and hyperaccumulation. Among several potential candidate genes that are probably involved in mediating the zinc-hypertolerant and zinc-hyperaccumulating trait is AhHMA3. The AhHMA3 gene is highly similar to AtHMA3 (AGI number: At4g30120) in A. thaliana, and its encoded protein belongs to the P-type IB ATPase family of integral membrane transporter proteins that transport transition metals. In contrast to the low AtHMA3 transcript levels in A. thaliana, the gene was found to be constitutively highly expressed across different Zn treatments in A. halleri, especially in shoots. In this study, the cloning and characterisation of the HMA3 gene and its promoter from Arabidopsis halleri (L.) O´KANE and AL´SHEHBAZ and Arabidopsis thaliana (L.) HEYNHOLD is described. Heterologously expressed AhHMA3 mediated enhanced tolerance to Zn and to a much lesser degree to cadmium (Cd) but not to cobalt (Co) in metal-sensitive mutant strains of budding yeast. It is demonstrated that the genome of A. halleri contains at least four copies of AhHMA3, AhHMA3-1 to AhHMA3-4. A copy-specific real-time RT-PCR indicated that an AhHMA3-1 related gene copy is the source of the constitutively high transcript level in A. halleri and not a gene copy similar to AhHMA3-2 or AhHMA3-4. In accordance with the enhanced AtHMA3mRNA transcript level in A. thaliana roots, an AtHMA3 promoter-GUS gene construct mediated GUS activity predominantly in the vascular tissues of roots and not in shoots. However, the observed AhHMA3-1 and AhHMA3-2 promoter-mediated GUS activity in A. thaliana or A. halleri plants did not reflect the constitutively high expression of AhHMA3 in shoots of A. halleri. It is suggested that other factors e. g. characteristic sequence inserts within the first intron of AhHMA3-1 might enable a constitutively high expression. Moreover, the unknown promoter of the AhHMA3-3 gene copy could be the source of the constitutively high AhHMA3 transcript levels in A. halleri. In that case, the AhHMA3-3 sequence is predicted to be highly homologous to AhHMA3-1. The lack of solid localisation data for the AhHMA3 protein prevents a clear functional assignment. The provided data suggest several possible functions of the AhHMA3 protein: Like AtHMA2 and AtHMA4 it might be localised to the plasma membrane and could contribute to the efficient translocation of Zn from root to shoot and/or to the cell-to-cell distribution of Zn in the shoot. If localised to the vacuolar membrane, then a role in maintaining a low cytoplasmic zinc concentration by vacuolar zinc sequestration is possible. In addition, AhHMA3 might be involved in the delivery of zinc ions to trichomes and mesophyll leaf cells that are major zinc storage sites in A. halleri.}, language = {en} } @misc{Koechert2007, type = {Master Thesis}, author = {K{\"o}chert, Karl}, title = {Development of a method to assess EAAT1 transcription levels in Alzheimer's disease}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15965}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Zur Zeit leiden ca. 24 Millionen Menschen auf der ganzen Welt unter Demenz, Alzheimer macht dabei 50-60\% aller Demenzf{\"a}lle aus. Da der Anteil der Bev{\"o}lkerung, der an Demenz leidet, proportional zum Alter zunimmt und der Anteil {\"a}lterer Menschen in der Gesellschaft von Jahr zu Jahr steigt, wird Alzheimer immer mehr zu einem ernstzunehmenden, gesellschaftlichen Problem. Zum Stand der heutigen Forschung ist es etabliert, dass die Aminos{\"a}ure Glutamat - quantitativ einer der wichtigsten Neurotransmitter im Zentralen Nervensystem (ZNS) - toxische Konzentrationen erreichen kann wenn sie - im Zuge der {\"U}bertragung von Aktionspotentialen - nach ihrer Freisetzung nicht aus dem Synaptischen Spalt entfernt wird. Viele Studien haben gezeigt, dass in der Alzheimerschen Krankheit die Glutamataufnahme beeintr{\"a}chtigt ist, was zu toxischen Konzentrationen von Glutamat und dem daraus folgenden Absterben von Neuronen f{\"u}hrt. Der exitatorische Aminos{\"a}uretransporter 1 (EAAT1) geh{\"o}rt zu der Familie der Na+-abh{\"a}ngigen Glutamattransporter und stellt nach EAAT2 den quantitativ wichtigsten Glutamattransporter im ZNS dar. In diesem Projekt wurde eine bis dahin f{\"u}r den Menschen nicht bekannte EAAT1 Spleißvariante, in der Exon 3 ausgeschnitten wird, nachgewiesen. Diese Variante wurde EAAT1Δ3 genannt und stellt damit mit EAAT1Δ9 die zweite f{\"u}r EAAT1 nachgewiesene Spleißvariante dar. Eine auf real-time RT-PCR basierende Methode wurde entwickelt, um die Transkripte von EAAT1 wildtyp (EAAT1 wt), EAAT1Δ3 und EAAT1Δ9 zu quantifizieren. Proben aus verschiedenen Hirnarealen wurden aus einem Set von Kontrollen und Alzheimerf{\"a}llen bei der Quantifizierung verwendet. Die gew{\"a}hlten Areale sind von der Alzheimerschen Krankheit unterschiedlich stark betroffen. Dies diente als interne Kontrolle f{\"u}r die durchgef{\"u}hrten Experimente und erm{\"o}glichte so die Differenzierung zwischen beobachteten Effekten: Nur Effekte die alleinig in von Alzheimer betroffenen Gehirnarealen auftreten, k{\"o}nnen als spezifisch f{\"u}r die Krankheit angesehen werden. Die Resultate diese Projektes zeigen, dass EAAT1Δ3 in sehr geringer Anzahl transkribiert wird, die nur 0.15\% der EAAT1 wt Transkription entspricht. Dahingegen entspricht das EAAT1 Δ9 Transkript im Durchschnitt 26.6\% des EAAT1 wt Transkripts. Es wurde nachgewiesen, dass die Transkriptionsrate aller EAAT1 Varianten in Alzheimerf{\"a}llen signifikant reduziert ist (P<0.0001). Dies unterst{\"u}tzt die Theorie, dass bei Alzheimerf{\"a}llen die EAAT1 Proteinexpression stark reduziert und der Glutamattransport, der normalerweise durch diesen Transporter gew{\"a}hrleistet wird, stark eingeschr{\"a}nkt ist. Dies wiederum resultiert in toxisch hohen Glutamatkonzentrationen und damit dem Absterben von Neuronen. Die gefundene Reduktion der EAAT1Transkription ist nicht spezifisch f{\"u}r Gehirnareale die von Alzheimer betroffen sind, sondern tritt in selbem Maße in nicht von Alzheimer betroffenen Gehirnarealen auf. Daraus l{\"a}sst sich schließen, dass die Reduktion der EAAT1 Transkription eher ein Resultat eines in der Alzheimerschen Krankheit pr{\"a}senten, grundlegenden Krankheitsmechanismus ist als deren Ursache.}, language = {en} } @misc{KortPeterKoopmanschap1983, author = {Kort, C. A. D. de and Peter, Martin G. and Koopmanschap, A. B.}, title = {Binding and degradation of juvenile hormone III by haemolymph proteins of the Colorado potato beetle: a re-examination}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16777}, year = {1983}, abstract = {The haemolymph of the adult Colorado potato beetle, Lepinotarsa decemlineata Say, contains a high molecular weight (MW > 200,000) JH-III specific binding protein. The Kd value of the protein for racemic JH-III is 1.3 ± 0.2 × 10-7 M. It has a lower affinity for racemic JH-I and it does not bind JH-III-diol or JH-III-acid. The binding protein does discriminate between the enantiomers of synthetic, racemic JH-III as was determined by stereochemical anaysis of the bound and the free JH-III. Incubation of racemic JH-III with crude haemolymph results in preferential formation of (10S)-JH-III-acid, the unnatural configuration. The JH-esterase present in L. decemlineata haemolymph is not enantioselective. It is concluded that the most important function of the binding protein is that of a specific carrier, protecting the natural hormone against degradation by esterases. The carrier does not protect JH-I as efficiently as the lower homologue.}, language = {en} } @phdthesis{Imranulhaq2008, author = {Imran ul-haq, Muhammad}, title = {Synthesis of fluorinated polymers in supercritical carbon dioxide (scCO₂)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19868}, school = {Universit{\"a}t Potsdam}, year = {2008}, abstract = {For the first time stabilizer-free vinylidene fluoride (VDF) polymerizations were carried out in homogeneous phase with supercritical CO₂. Polymerizations were carried out at 140°C, 1500 bar and were initiated with di-tert-butyl peroxide (DTBP). In-line FT-NIR (Fourier Transform- Near Infrared) spectroscopy showed that complete monomer conversion may be obtained. Molecular weights were determined via size-exclusion chromatography (SEC) and polymer end group analysis by 1H-NMR spectroscopy. The number average molecular weights were below 104 g∙mol-1 and polydispersities ranged from 3.1 to 5.7 depending on DTBP and VDF concentration. To allow for isothermal reactions high CO₂ contents ranging from 61 to 83 wt.\% were used. The high-temperature, high-pressure conditions were required for homogeneous phase polymerization. These conditions did not alter the amount of defects in VDF chaining. Scanning electron microscopy (SEM) indicated that regular stack-type particles were obtained upon expansion of the homogeneous polymerization mixture. To reduce the required amount of initiator, further VDF polymerizations using chain transfer agents (CTAs) to control molecular weights were carried out in homogeneous phase with supercritical carbon dioxide (scCO₂) at 120 °C and 1500 bar. Using perfluorinated hexyl iodide as CTA, polymers of low polydispersity ranging from 1.5 to 1.2 at the highest iodide concentration of 0.25 mol·L-1 were obtained. Electrospray ionization- mass spectroscopy (ESI-MS) indicates the absence of initiator derived end groups, supporting livingness of the system. The "livingness" is based on the labile C-I bond. However, due to the weakness of the C-I bond perfluorinated hexyl iodide also contributes to initiation. To allow for kinetic analyses of VDF polymerizations the CTA should not contribute to initiation. Therefore, additional CTAs were applied: BrCCl3, C6F13Br and C6F13H. It was found that C6F13H does not contribute to initiation. At 120°C and 1500 bar kp/kt0.5~ 0.64 (L·mol-1·s-1)0.5 was derived. The chain transfer constant (CT) at 120°C has been determined to be 8·10-1, 9·10-2 and 2·10-4 for C6F13I, C6F13Br and C6F13H, respectively. These CT values are associated with the bond energy of the C-X bond. Moreover, the labile C-I bond allows for functionalization of the polymer to triazole end groups applying click reactions. After substitution of the iodide end group by an azide group 1,3 dipolar cycloadditions with alkynes yield polymers with 1,2,3 triazole end groups. Using symmetrical alkynes the reactions may be carried out in the absence of any catalyst. This end-functionalized poly (vinylidene fluoride) (PVDF) has higher thermal stability as compared to the normal PVDF. PVDF samples from homogeneous phase polymerizations in supercritical CO₂ and subsequent expansion to ambient conditions were analyzed with respect to polymer end groups, crystallinity, type of polymorphs and morphology. Upon expansion the polymer was obtained as white powder. Scanning electron microscopy (SEM) showed that DTBP derived polymer end groups led to stack-type particles whereas sponge- or rose-type particles were obtained in case of CTA fragments as end groups. Fourier-Transform Infrared spectroscopy and wide angle X-ray diffraction indicated that the type of polymorph, α or β crystal phase was significantly affected by the type of end group. The content of β-phase material, which is responsible for piezoelectricity of PVDF, is the highest for polymer with DTBP-derived end groups. In addition, the crystallinity of the material, as determined via differential scanning calorimetry is affected by the end groups and polymer molecular weights. For example, crystallinity ranges from around 26 \% for DTBP-derived end groups to a maximum of 62 \% for end groups originating from perfluorinated hexyl iodide for polymers with Mn ~2200 g·mol-1. Expansion of the homogeneous polymerization mixture results in particle formation by a non-optimized RESS (Rapid Expansion from Supercritical Solution) process. Thus, it was tested how polymer end groups affect the particles size distribution obtained from RESS process under controlled conditions (T = 50°C and P = 200 bar). In all RESS experiments, small primary PVDF with diameters less than 100 nm without the use of liquid solvents, surfactants, or other additives were produced. A strong correlation between particle size and particle size distribution with polymer end groups and molecular weight of the original material was observed. The smallest particles were found for RESS of PVDF with Mn~ 4000 g·mol-1 and PFHI (C6F13I) - derived end groups.}, language = {en} } @misc{KoechyBrakenhielm2008, author = {K{\"o}chy, Martin and Br{\aa}kenhielm, Sven}, title = {Separation of effects of moderate N deposition from natural change in ground vegetation of forests and bogs}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16621}, year = {2008}, abstract = {The effect of moderate rates of nitrogen deposition on ground floor vegetation is poorly predicted by uncontrolled surveys or fertilization experiments using high rates of nitrogen (N) addition. We compared the temporal trends of ground floor vegetation in permanent plots with moderate (7-13 kg ha-1 year-1) and lower bulk N deposition (4-6 kg ha-1 year-1) in southern Sweden during 1982-1998. We examined whether trends differed between growth forms (vascular plants and bryophytes) and vegetation types (three types of coniferous forest, deciduous forest, and bog). Trends of site-standardized cover and richness varied among growth forms, vegetation types, and deposition regions. Cover in spruce forests decreased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs cover decreased faster with low deposition. Cover of bryophytes in spruce forests increased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs and deciduous forests there was a strong non-linear increase with moderate deposition. The trend of number of vascular plants was constant with moderate and decreased with low deposition. We found no trend in the number of bryophyte species. We propose that the decrease of cover and number with low deposition was related to normal ecosystem development (increased shading), suggesting that N deposition maintained or increased the competitiveness of some species in the moderate-deposition region. Deposition had no consistent negative effect on vegetation suggesting that it is less important than normal successional processes.}, language = {en} } @misc{ElsenbeerLackCassel1995, author = {Elsenbeer, Helmut and Lack, Andreas and Cassel, Keith}, title = {Chemical fingerprints of hydrological compartments and flow paths at La Cuenca, western Amazonia}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16937}, year = {1995}, abstract = {A forested first-order catchment in western Amazonia was monitored for 2 years to determine the chemical fingerprints of precipitation, throughfall, overland flow, pipe flow, soil water, groundwater, and streamflow. We used five tracers (hydrogen, calcium, magnesium, potassium, and silica) to distinguish "fast" flow paths mainly influenced by the biological subsystem from "slow" flow paths in the geochemical subsystem. The former comprise throughfall, overland flow, and pipe flow and are characterized by a high potassium/silica ratio; the latter are represented by soil water and groundwater, which have a low potassium/silica ratio. Soil water and groundwater differ with respect to calcium and magnesium. The groundwater-controlled streamflow chemistry is strongly modified by contributions from fast flow paths during precipitation events. The high potassium/silica ratio of these flow paths suggests that the storm flow response at La Cuenca is dominated by event water.}, language = {en} } @misc{ElsenbeerLorieriBonell1995, author = {Elsenbeer, Helmut and Lorieri, Daniel and Bonell, Mike}, title = {Mixing model approaches to estimate storm flow sources in an overland flow-dominated tropical rain forest catchment}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16948}, year = {1995}, abstract = {Previous hydrometric studies demonstrated the prevalence of overland flow as a hydrological pathway in the tropical rain forest catchment of South Creek, northeast Queensland. The purpose of this study was to consider this information in a mixing analysis with the aim of identifying sources of, and of estimating their contribution to, storm flow during two events in February 1993. K and acid-neutralizing capacity (ANC) were used as tracers because they provided the best separation of the potential sources, saturation overland flow, soil water from depths of 0.3, 0.6, and 1.2 m, and hillslope groundwater in a two-dimensional mixing plot. It was necessary to distinguish between saturation overland flow, generated at the soil surface and following unchanneled pathways, and overland flow in incised pathways. This latter type of overland flow was a mixture of saturation overland flow (event water) with high concentrations of K and a low ANC, soil water (preevent water) with low concentrations of K and a low ANC, and groundwater (preevent water) with low concentrations of K and a high ANC. The same sources explained the streamwater chemistry during the two events with strongly differing rainfall and antecedent moisture conditions. The contribution of saturation overland flow dominated the storm flow during the first, high-intensity, 178-mm event, while the contribution of soil water reached 50\% during peak flow of the second, low-intensity, 44-mm event 5 days later. This latter result is remarkably similar to soil water contributions to storm flow in mountainous forested catchments of the southeastern United States. In terms of event and preevent water the storm flow hydrograph of the high-intensity event is dominated by event water and that of the low-intensity event by preevent water. This study highlights the problems of applying mixing analyses to overland flow-dominated catchments and soil environments with a poorly developed vertical chemical zonation and emphasizes the need for independent hydrometric information for a complete characterization of watershed hydrology and chemistry.}, language = {en} } @misc{HoehleWeissenbornKieferetal.2004, author = {H{\"o}hle, Barbara and Weissenborn, J{\"u}rgen and Kiefer, Dorothea and Schulz, Antje and Schmitz, Michaela}, title = {Functional elements in infants' speech processing : the role of determiners in the syntactic categorization of lexical elements}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16285}, year = {2004}, abstract = {How do children determine the syntactic category of novel words? In this article we present the results of 2 experiments that investigated whether German children between 12 and 16 months of age can use distributional knowledge that determiners precede nouns and subject pronouns precede verbs to syntactically categorize adjacent novel words. Evidence from the head-turn preference paradigm shows that, although 12- to 13-month-olds cannot do this, 14- to 16-month-olds are able to use a determiner to categorize a following novel word as a noun. In contrast, no categorization effect was found for a novel word following a subject pronoun. To understand this difference we analyzed adult child-directed speech. This analysis showed that there are in fact stronger co-occurrence relations between determiners and nouns than between subject pronouns and verbs. Thus, in German determiners may be more reliable cues to the syntactic category of an adjacent novel word than are subject pronouns. We propose that the capacity to syntactically categorize novel words, demonstrated here for the first time in children this young, mediates between the recognition of the specific morphosyntactic frame in which a novel word appears and the word-to-world mapping that is needed to build up a semantic representation for the novel word.}, language = {en} } @misc{HoehleSchmitzMuelleretal.2006, author = {H{\"o}hle, Barbara and Schmitz, Michaela and M{\"u}ller, Anja and Weissenborn, J{\"u}rgen}, title = {The recognition of discontinuous verbal dependencies by German 19-month-olds : evidence for lexical and structural influences on children's early processing capacities}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16297}, year = {2006}, abstract = {Recent work has shown that English-learning 18-month-olds can detect the relationship between discontinuous morphemes such as is and -ing in Grandma is always running (Gomez, 2002; Santelmann \& Jusczyk, 1998) but only at a maximum of 3 intervening syllables. In this article we examine the tracking of discontinuous dependencies in children acquiring German. Due to freer word order, German allows for greater distances between dependent elements and a greater syntactic variety of the intervening elements than English does. The aim of this study was to investigate whether factors other than distance may influence the child's capacity to recognize discontinuous elements. Our findings provide evidence that children's recognition capacities are affected not only by distance but also by their ability to linguistically analyze the material intervening between the dependent elements. We speculate that this result supports the existence of processing mechanisms that reduce a discontinuous relation to a local one based on subcategorization relations.}, language = {en} } @misc{HoehlevandeVijverWeissenborn2006, author = {H{\"o}hle, Barbara and van de Vijver, Ruben and Weissenborn, J{\"u}rgen}, title = {Word processing at 19 months and its relation to language performance at 30 months : a retrospective analysis of data from German learning children}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16302}, year = {2006}, abstract = {Recent research has shown that the early lexical representations children establish in their second year of life already seem to be phonologically detailed enough to allow differentiation from very similar forms. In contrast to these findings children with specific language impairment show problems in discriminating phonologically similar word forms up to school age. In our study we investigated the question whether there would be differences in the processing of phonological details in normally developing and in children with low language performance in the second year of life. This was done by a retrospective study in which in the processing of phonological details was tested by a preferential looking experiment when the children were 19 months old. At the age of 30 months children were tested with a standardized German test of language comprehension and production (SETK2). The preferential looking data at 19 months revealed an opposite reaction pattern for the two groups: while the children scoring normally in the SETK2 increase their fixations of a pictured object only when it was named with the correct word, children with later low language performance did so only when presented with a phonologically slightly deviant mispronunciation. We suggest that this pattern does not point to a specific deficit in processing phonological information in these children but might be related to an instability of early phonological representations, and/or a generalized problem of information processing as compared to typically developing children.}, language = {en} } @inproceedings{Piskorski2008, author = {Piskorski, Jakub}, title = {ExPRESS : extraction pattern recognition engine and specification suite}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27227}, year = {2008}, abstract = {The emergence of information extraction (IE) oriented pattern engines has been observed during the last decade. Most of them exploit heavily finite-state devices. This paper introduces ExPRESS - a new extraction pattern engine, whose rules are regular expressions over flat feature structures. The underlying pattern language is a blend of two previously introduced IE oriented pattern formalisms, namely, JAPE, used in the widely known GATE system, and the unificationbased XTDL formalism used in SProUT. A brief and technical overview of ExPRESS, its pattern language and the pool of its native linguistic components is given. Furthermore, the implementation of the grammar interpreter is addressed too.}, language = {en} } @inproceedings{OPUS4-1412, title = {The 3rd international IEEE scientific conference on physics and control (PhysCon 2007) : September 3rd-7th 2007 at the University of Potsdam}, editor = {Kurths, J{\"u}rgen and Fradkov, Alexander and Chen, Guanrong}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15228}, pages = {345}, year = {2007}, abstract = {During the last few years there was a tremendous growth of scientific activities in the fields related to both Physics and Control theory: nonlinear dynamics, micro- and nanotechnologies, self-organization and complexity, etc. New horizons were opened and new exciting applications emerged. Experts with different backgrounds starting to work together need more opportunities for information exchange to improve mutual understanding and cooperation. The Conference "Physics and Control 2007" is the third international conference focusing on the borderland between Physics and Control with emphasis on both theory and applications. With its 2007 address at Potsdam, Germany, the conference is located for the first time outside of Russia. The major goal of the Conference is to bring together researchers from different scientific communities and to gain some general and unified perspectives in the studies of controlled systems in physics, engineering, chemistry, biology and other natural sciences. We hope that the Conference helps experts in control theory to get acquainted with new interesting problems, and helps experts in physics and related fields to know more about ideas and tools from the modern control theory.}, language = {en} } @phdthesis{Miteva2007, author = {Miteva, Rositsa Stoycheva}, title = {Electron acceleration at localized wave structures in the solar corona}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14775}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Our dynamic Sun manifests its activity by different phenomena: from the 11-year cyclic sunspot pattern to the unpredictable and violent explosions in the case of solar flares. During flares, a huge amount of the stored magnetic energy is suddenly released and a substantial part of this energy is carried by the energetic electrons, considered to be the source of the nonthermal radio and X-ray radiation. One of the most important and still open question in solar physics is how the electrons are accelerated up to high energies within (the observed in the radio emission) short time scales. Because the acceleration site is extremely small in spatial extent as well (compared to the solar radius), the electron acceleration is regarded as a local process. The search for localized wave structures in the solar corona that are able to accelerate electrons together with the theoretical and numerical description of the conditions and requirements for this process, is the aim of the dissertation. Two models of electron acceleration in the solar corona are proposed in the dissertation: I. Electron acceleration due to the solar jet interaction with the background coronal plasma (the jet--plasma interaction) A jet is formed when the newly reconnected and highly curved magnetic field lines are relaxed by shooting plasma away from the reconnection site. Such jets, as observed in soft X-rays with the Yohkoh satellite, are spatially and temporally associated with beams of nonthermal electrons (in terms of the so-called type III metric radio bursts) propagating through the corona. A model that attempts to give an explanation for such observational facts is developed here. Initially, the interaction of such jets with the background plasma leads to an (ion-acoustic) instability associated with growing of electrostatic fluctuations in time for certain range of the jet initial velocity. During this process, any test electron that happen to feel this electrostatic wave field is drawn to co-move with the wave, gaining energy from it. When the jet speed has a value greater or lower than the one, required by the instability range, such wave excitation cannot be sustained and the process of electron energization (acceleration and/or heating) ceases. Hence, the electrons can propagate further in the corona and be detected as type III radio burst, for example. II. Electron acceleration due to attached whistler waves in the upstream region of coronal shocks (the electron--whistler--shock interaction) Coronal shocks are also able to accelerate electrons, as observed by the so-called type II metric radio bursts (the radio signature of a shock wave in the corona). From in-situ observations in space, e.g., at shocks related to co-rotating interaction regions, it is known that nonthermal electrons are produced preferably at shocks with attached whistler wave packets in their upstream regions. Motivated by these observations and assuming that the physical processes at shocks are the same in the corona as in the interplanetary medium, a new model of electron acceleration at coronal shocks is presented in the dissertation, where the electrons are accelerated by their interaction with such whistlers. The protons inflowing toward the shock are reflected there by nearly conserving their magnetic moment, so that they get a substantial velocity gain in the case of a quasi-perpendicular shock geometry, i.e, the angle between the shock normal and the upstream magnetic field is in the range 50--80 degrees. The so-accelerated protons are able to excite whistler waves in a certain frequency range in the upstream region. When these whistlers (comprising the localized wave structure in this case) are formed, only the incoming electrons are now able to interact resonantly with them. But only a part of these electrons fulfill the the electron--whistler wave resonance condition. Due to such resonant interaction (i.e., of these electrons with the whistlers), the electrons are accelerated in the electric and magnetic wave field within just several whistler periods. While gaining energy from the whistler wave field, the electrons reach the shock front and, subsequently, a major part of them are reflected back into the upstream region, since the shock accompanied with a jump of the magnetic field acts as a magnetic mirror. Co-moving with the whistlers now, the reflected electrons are out of resonance and hence can propagate undisturbed into the far upstream region, where they are detected in terms of type II metric radio bursts. In summary, the kinetic energy of protons is transfered into electrons by the action of localized wave structures in both cases, i.e., at jets outflowing from the magnetic reconnection site and at shock waves in the corona.}, language = {en} } @misc{AscherChinReich1994, author = {Ascher, Uri M. and Chin, Hongsheng and Reich, Sebastian}, title = {Stabilization of DAEs and invariant manifolds}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15625}, year = {1994}, abstract = {Many methods have been proposed for the stabilization of higher index differential-algebraic equations (DAEs). Such methods often involve constraint differentiation and problem stabilization, thus obtaining a stabilized index reduction. A popular method is Baumgarte stabilization, but the choice of parameters to make it robust is unclear in practice. Here we explain why the Baumgarte method may run into trouble. We then show how to improve it. We further develop a unifying theory for stabilization methods which includes many of the various techniques proposed in the literature. Our approach is to (i) consider stabilization of ODEs with invariants, (ii) discretize the stabilizing term in a simple way, generally different from the ODE discretization, and (iii) use orthogonal projections whenever possible. The best methods thus obtained are related to methods of coordinate projection. We discuss them and make concrete algorithmic suggestions.}, language = {en} } @misc{LeimkuhlerReich1994, author = {Leimkuhler, Benedict and Reich, Sebastian}, title = {Symplectic integration of constrained Hamiltonian systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15653}, year = {1994}, abstract = {A Hamiltonian system in potential form (formula in the original abstract) subject to smooth constraints on q can be viewed as a Hamiltonian system on a manifold, but numerical computations must be performed in Rn. In this paper methods which reduce "Hamiltonian differential algebraic equations" to ODEs in Euclidean space are examined. The authors study the construction of canonical parameterizations or local charts as well as methods based on the construction of ODE systems in the space in which the constraint manifold is embedded which preserve the constraint manifold as an invariant manifold. In each case, a Hamiltonian system of ordinary differential equations is produced. The stability of the constraint invariants and the behavior of the original Hamiltonian along solutions are investigated both numerically and analytically.}, language = {en} } @misc{AscherChinPetzoldetal.1994, author = {Ascher, Uri M. and Chin, Hongsheng and Petzold, Linda R. and Reich, Sebastian}, title = {Stabilization of constrained mechanical systems with DAEs and invariant manifolds}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15698}, year = {1994}, abstract = {Many methods have been proposed for the simulation of constrained mechanical systems. The most obvious of these have mild instabilities and drift problems. Consequently, stabilization techniques have been proposed A popular stabilization method is Baumgarte's technique, but the choice of parameters to make it robust has been unclear in practice. Some of the simulation methods that have been proposed and used in computations are reviewed here, from a stability point of view. This involves concepts of differential-algebraic equation (DAE) and ordinary differential equation (ODE) invariants. An explanation of the difficulties that may be encountered using Baumgarte's method is given, and a discussion of why a further quest for better parameter values for this method will always remain frustrating is presented. It is then shown how Baumgarte's method can be improved. An efficient stabilization technique is proposed, which may employ explicit ODE solvers in case of nonstiff or highly oscillatory problems and which relates to coordinate projection methods. Examples of a two-link planar robotic arm and a squeezing mechanism illustrate the effectiveness of this new stabilization method.}, language = {en} } @inproceedings{Watson2008, author = {Watson, Bruce W.}, title = {Advances in automata implementation techniques (Abstract)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27094}, year = {2008}, language = {en} } @inproceedings{Barthelemy2008, author = {Barth{\´e}lemy, Fran{\c{c}}ois}, title = {Finite-state compilation of feature structures for two-level morphology}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27120}, year = {2008}, abstract = {This paper describes a two-level formalism where feature structures are used in contextual rules. Whereas usual two-level grammars describe rational sets over symbol pairs, this new formalism uses tree structured regular expressions. They allow an explicit and precise definition of the scope of feature structures. A given surface form may be described using several feature structures. Feature unification is expressed in contextual rules using variables, like in a unification grammar. Grammars are compiled in finite state multi-tape transducers.}, language = {en} } @inproceedings{BlancConstantWatrin2008, author = {Blanc, Olivier and Constant, Matthieu and Watrin, Patrick}, title = {Segmentation in super-chunks with a finite-state approach}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27133}, year = {2008}, abstract = {Since Harris' parser in the late 50s, multiword units have been progressively integrated in parsers. Nevertheless, in the most part, they are still restricted to compound words, that are more stable and less numerous. Actually, language is full of semi-fixed expressions that also form basic semantic units: semi-fixed adverbial expressions (e.g. time), collocations. Like compounds, the identification of these structures limits the combinatorial complexity induced by lexical ambiguity. In this paper, we detail an experiment that largely integrates these notions in a finite-state procedure of segmentation into super-chunks, preliminary to a parser.We show that the chunker, developped for French, reaches 92.9\% precision and 98.7\% recall. Moreover, multiword units realize 36.6\% of the attachments within nominal and prepositional phrases.}, language = {en} } @inproceedings{BonfanteLeRoux2008, author = {Bonfante, Guillaume and Le Roux, Joseph}, title = {Intersection optimization is NP-complete}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27146}, year = {2008}, abstract = {Finite state methods for natural language processing often require the construction and the intersection of several automata. In this paper, we investigate the question of determining the best order in which these intersections should be performed. We take as an example lexical disambiguation in polarity grammars. We show that there is no efficient way to minimize the state complexity of these intersections.}, language = {en} } @inproceedings{Daciuk2008, author = {Daciuk, Jan}, title = {Perfect hashing tree automata}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27163}, year = {2008}, abstract = {We present an algorithm that computes a function that assigns consecutive integers to trees recognized by a deterministic, acyclic, finite-state, bottom-up tree automaton. Such function is called minimal perfect hashing. It can be used to identify trees recognized by the automaton. Its value may be seen as an index in some other data structures. We also present an algorithm for inverted hashing.}, language = {en} } @inproceedings{PadroPadro2008, author = {Padr{\´o}, Muntsa and Padr{\´o}, Llu{\´i}s}, title = {ME-CSSR : an extension of CSSR using maximum entropy models}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27210}, year = {2008}, abstract = {In this work an extension of CSSR algorithm using Maximum Entropy Models is introduced. Preliminary experiments to perform Named Entity Recognition with this new system are presented.}, language = {en} } @phdthesis{Radeff2014, author = {Radeff, Giuditta}, title = {Geohistory of the Central Anatolian Plateau southern margin (southern Turkey)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71865}, school = {Universit{\"a}t Potsdam}, year = {2014}, abstract = {The Adana Basin of southern Turkey, situated at the SE margin of the Central Anatolian Plateau is ideally located to record Neogene topographic and tectonic changes in the easternmost Mediterranean realm. Using industry seismic reflection data we correlate 34 seismic profiles with corresponding exposed units in the Adana Basin. The time-depth conversion of the interpreted seismic profiles allows us to reconstruct the subsidence curve of the Adana Basin and to outline the occurrence of a major increase in both subsidence and sedimentation rates at 5.45 - 5.33 Ma, leading to the deposition of almost 1500 km3 of conglomerates and marls. Our provenance analysis of the conglomerates reveals that most of the sediment is derived from and north of the SE margin of the Central Anatolian Plateau. A comparison of these results with the composition of recent conglomerates and the present drainage basins indicates major changes between late Messinian and present-day source areas. We suggest that these changes in source areas result of uplift and ensuing erosion of the SE margin of the plateau. This hypothesis is supported by the comparison of the Adana Basin subsidence curve with the subsidence curve of the Mut Basin, a mainly Neogene basin located on top of the Central Anatolian Plateau southern margin, showing that the Adana Basin subsidence event is coeval with an uplift episode of the plateau southern margin. The collection of several fault measurements in the Adana region show different deformation styles for the NW and SE margins of the Adana Basin. The weakly seismic NW portion of the basin is characterized by extensional and transtensional structures cutting Neogene deposits, likely accomodating the differential uplift occurring between the basin and the SE margin of the plateau. We interpret the tectonic evolution of the southern flank of the Central Anatolian Plateau and the coeval subsidence and sedimentation in the Adana Basin to be related to deep lithospheric processes, particularly lithospheric delamination and slab break-off.}, language = {en} } @phdthesis{Kellermann2011, author = {Kellermann, Thorsten}, title = {Accurate numerical relativity simulations of non-vacuumspace-times in two dimensions and applications to critical collapse}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59578}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This Thesis puts its focus on the physics of neutron stars and its description with methods of numerical relativity. In the first step, a new numerical framework the Whisky2D code will be developed, which solves the relativistic equations of hydrodynamics in axisymmetry. Therefore we consider an improved formulation of the conserved form of these equations. The second part will use the new code to investigate the critical behaviour of two colliding neutron stars. Considering the analogy to phase transitions in statistical physics, we will investigate the evolution of the entropy of the neutron stars during the whole process. A better understanding of the evolution of thermodynamical quantities, like the entropy in critical process, should provide deeper understanding of thermodynamics in relativity. More specifically, we have written the Whisky2D code, which solves the general-relativistic hydrodynamics equations in a flux-conservative form and in cylindrical coordinates. This of course brings in 1/r singular terms, where r is the radial cylindrical coordinate, which must be dealt with appropriately. In the above-referenced works, the flux operator is expanded and the 1/r terms, not containing derivatives, are moved to the right-hand-side of the equation (the source term), so that the left hand side assumes a form identical to the one of the three-dimensional (3D) Cartesian formulation. We call this the standard formulation. Another possibility is not to split the flux operator and to redefine the conserved variables, via a multiplication by r. We call this the new formulation. The new equations are solved with the same methods as in the Cartesian case. From a mathematical point of view, one would not expect differences between the two ways of writing the differential operator, but, of course, a difference is present at the numerical level. Our tests show that the new formulation yields results with a global truncation error which is one or more orders of magnitude smaller than those of alternative and commonly used formulations. The second part of the Thesis uses the new code for investigations of critical phenomena in general relativity. In particular, we consider the head-on-collision of two neutron stars in a region of the parameter space where two final states a new stable neutron star or a black hole, lay close to each other. In 1993, Choptuik considered one-parameter families of solutions, S[P], of the Einstein-Klein-Gordon equations for a massless scalar field in spherical symmetry, such that for every P > P⋆, S[P] contains a black hole and for every P < P⋆, S[P] is a solution not containing singularities. He studied numerically the behavior of S[P] as P → P⋆ and found that the critical solution, S[P⋆], is universal, in the sense that it is approached by all nearly-critical solutions regardless of the particular family of initial data considered. All these phenomena have the common property that, as P approaches P⋆, S[P] approaches a universal solution S[P⋆] and that all the physical quantities of S[P] depend only on |P - P⋆|. The first study of critical phenomena concerning the head-on collision of NSs was carried out by Jin and Suen in 2007. In particular, they considered a series of families of equal-mass NSs, modeled with an ideal-gas EOS, boosted towards each other and varied the mass of the stars, their separation, velocity and the polytropic index in the EOS. In this way they could observe a critical phenomenon of type I near the threshold of black-hole formation, with the putative solution being a nonlinearly oscillating star. In a successive work, they performed similar simulations but considering the head-on collision of Gaussian distributions of matter. Also in this case they found the appearance of type-I critical behaviour, but also performed a perturbative analysis of the initial distributions of matter and of the merged object. Because of the considerable difference found in the eigenfrequencies in the two cases, they concluded that the critical solution does not represent a system near equilibrium and in particular not a perturbed Tolmann-Oppenheimer-Volkoff (TOV) solution. In this Thesis we study the dynamics of the head-on collision of two equal-mass NSs using a setup which is as similar as possible to the one considered above. While we confirm that the merged object exhibits a type-I critical behaviour, we also argue against the conclusion that the critical solution cannot be described in terms of equilibrium solution. Indeed, we show that, in analogy with what is found in, the critical solution is effectively a perturbed unstable solution of the TOV equations. Our analysis also considers fine-structure of the scaling relation of type-I critical phenomena and we show that it exhibits oscillations in a similar way to the one studied in the context of scalar-field critical collapse.}, language = {en} } @phdthesis{Berger2012, author = {Berger, Florian}, title = {Different modes of cooperative transport by molecular motors}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60319}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {Cargo transport by molecular motors is ubiquitous in all eukaryotic cells and is typically driven cooperatively by several molecular motors, which may belong to one or several motor species like kinesin, dynein or myosin. These motor proteins transport cargos such as RNAs, protein complexes or organelles along filaments, from which they unbind after a finite run length. Understanding how these motors interact and how their movements are coordinated and regulated is a central and challenging problem in studies of intracellular transport. In this thesis, we describe a general theoretical framework for the analysis of such transport processes, which enables us to explain the behavior of intracellular cargos based on the transport properties of individual motors and their interactions. Motivated by recent in vitro experiments, we address two different modes of transport: unidirectional transport by two identical motors and cooperative transport by actively walking and passively diffusing motors. The case of cargo transport by two identical motors involves an elastic coupling between the motors that can reduce the motors' velocity and/or the binding time to the filament. We show that this elastic coupling leads, in general, to four distinct transport regimes. In addition to a weak coupling regime, kinesin and dynein motors are found to exhibit a strong coupling and an enhanced unbinding regime, whereas myosin motors are predicted to attain a reduced velocity regime. All of these regimes, which we derive both by analytical calculations and by general time scale arguments, can be explored experimentally by varying the elastic coupling strength. In addition, using the time scale arguments, we explain why previous studies came to different conclusions about the effect and relevance of motor-motor interference. In this way, our theory provides a general and unifying framework for understanding the dynamical behavior of two elastically coupled molecular motors. The second mode of transport studied in this thesis is cargo transport by actively pulling and passively diffusing motors. Although these passive motors do not participate in active transport, they strongly enhance the overall cargo run length. When an active motor unbinds, the cargo is still tethered to the filament by the passive motors, giving the unbound motor the chance to rebind and continue its active walk. We develop a stochastic description for such cooperative behavior and explicitly derive the enhanced run length for a cargo transported by one actively pulling and one passively diffusing motor. We generalize our description to the case of several pulling and diffusing motors and find an exponential increase of the run length with the number of involved motors.}, language = {en} } @phdthesis{Hoffmann2011, author = {Hoffmann, Anne}, title = {Comparative aerosol studies based on multi-wavelength Raman LIDAR at Ny-{\AA}lesund, Spitsbergen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52426}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {The Arctic is a particularly sensitive area with respect to climate change due to the high surface albedo of snow and ice and the extreme radiative conditions. Clouds and aerosols as parts of the Arctic atmosphere play an important role in the radiation budget, which is, as yet, poorly quantified and understood. The LIDAR (Light Detection And Ranging) measurements presented in this PhD thesis contribute with continuous altitude resolved aerosol profiles to the understanding of occurrence and characteristics of aerosol layers above Ny-{\AA}lesund, Spitsbergen. The attention was turned to the analysis of periods with high aerosol load. As the Arctic spring troposphere exhibits maximum aerosol optical depths (AODs) each year, March and April of both the years 2007 and 2009 were analyzed. Furthermore, stratospheric aerosol layers of volcanic origin were analyzed for several months, subsequently to the eruptions of the Kasatochi and Sarychev volcanoes in summer 2008 and 2009, respectively. The Koldewey Aerosol Raman LIDAR (KARL) is an instrument for the active remote sensing of atmospheric parameters using pulsed laser radiation. It is operated at the AWIPEV research base and was fundamentally upgraded within the framework of this PhD project. It is now equipped with a new telescope mirror and new detection optics, which facilitate atmospheric profiling from 450m above sea level up to the mid-stratosphere. KARL provides highly resolved profiles of the scattering characteristics of aerosol and cloud particles (backscattering, extinction and depolarization) as well as water vapor profiles within the lower troposphere. Combination of KARL data with data from other instruments on site, namely radiosondes, sun photometer, Micro Pulse LIDAR, and tethersonde system, resulted in a comprehensive data set of scattering phenomena in the Arctic atmosphere. The two spring periods March and April 2007 and 2009 were at first analyzed based on meteorological parameters, like local temperature and relative humidity profiles as well as large scale pressure patterns and air mass origin regions. Here, it was not possible to find a clear correlation between enhanced AOD and air mass origin. However, in a comparison of two cloud free periods in March 2007 and April 2009, large AOD values in 2009 coincided with air mass transport through the central Arctic. This suggests the occurrence of aerosol transformation processes during the aerosol transport to Ny-{\AA}lesund. Measurements on 4 April 2009 revealed maximum AOD values of up to 0.12 and aerosol size distributions changing with altitude. This and other performed case studies suggest the differentiation between three aerosol event types and their origin: Vertically limited aerosol layers in dry air, highly variable hygroscopic boundary layer aerosols and enhanced aerosol load across wide portions of the troposphere. For the spring period 2007, the available KARL data were statistically analyzed using a characterization scheme, which is based on optical characteristics of the scattering particles. The scheme was validated using several case studies. Volcanic eruptions in the northern hemisphere in August 2008 and June 2009 arose the opportunity to analyze volcanic aerosol layers within the stratosphere. The rate of stratospheric AOD change was similar within both years with maximum values above 0.1 about three to five weeks after the respective eruption. In both years, the stratospheric AOD persisted at higher rates than usual until the measurements were stopped in late September due to technical reasons. In 2008, up to three aerosol layers were detected, the layer structure in 2009 was characterized by up to six distinct and thin layers which smeared out to one broad layer after about two months. The lowermost aerosol layer was continuously detected at the tropopause altitude. Three case studies were performed, all revealed rather large indices of refraction of m = (1.53-1.55) - 0.02i, suggesting the presence of an absorbing carbonaceous component. The particle radius, derived with inversion calculations, was also similar in both years with values ranging from 0.16 to 0.19 μm. However, in 2009, a second mode in the size distribution was detected at about 0.5 μm. The long term measurements with the Koldewey Aerosol Raman LIDAR in Ny-{\AA}lesund provide the opportunity to study Arctic aerosols in the troposphere and the stratosphere not only in case studies but on longer time scales. In this PhD thesis, both, tropospheric aerosols in the Arctic spring and stratospheric aerosols following volcanic eruptions have been described qualitatively and quantitatively. Case studies and comparative studies with data of other instruments on site allowed for the analysis of microphysical aerosol characteristics and their temporal evolution.}, language = {en} } @phdthesis{Bierbaum2011, author = {Bierbaum, Veronika}, title = {Chemomechanical coupling and motor cycles of the molecular motor myosin V}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53614}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {In the living cell, the organization of the complex internal structure relies to a large extent on molecular motors. Molecular motors are proteins that are able to convert chemical energy from the hydrolysis of adenosine triphosphate (ATP) into mechanical work. Being about 10 to 100 nanometers in size, the molecules act on a length scale, for which thermal collisions have a considerable impact onto their motion. In this way, they constitute paradigmatic examples of thermodynamic machines out of equilibrium. This study develops a theoretical description for the energy conversion by the molecular motor myosin V, using many different aspects of theoretical physics. Myosin V has been studied extensively in both bulk and single molecule experiments. Its stepping velocity has been characterized as a function of external control parameters such as nucleotide concentration and applied forces. In addition, numerous kinetic rates involved in the enzymatic reaction of the molecule have been determined. For forces that exceed the stall force of the motor, myosin V exhibits a 'ratcheting' behaviour: For loads in the direction of forward stepping, the velocity depends on the concentration of ATP, while for backward loads there is no such influence. Based on the chemical states of the motor, we construct a general network theory that incorporates experimental observations about the stepping behaviour of myosin V. The motor's motion is captured through the network description supplemented by a Markov process to describe the motor dynamics. This approach has the advantage of directly addressing the chemical kinetics of the molecule, and treating the mechanical and chemical processes on equal grounds. We utilize constraints arising from nonequilibrium thermodynamics to determine motor parameters and demonstrate that the motor behaviour is governed by several chemomechanical motor cycles. In addition, we investigate the functional dependence of stepping rates on force by deducing the motor's response to external loads via an appropriate Fokker-Planck equation. For substall forces, the dominant pathway of the motor network is profoundly different from the one for superstall forces, which leads to a stepping behaviour that is in agreement with the experimental observations. The extension of our analysis to Markov processes with absorbing boundaries allows for the calculation of the motor's dwell time distributions. These reveal aspects of the coordination of the motor's heads and contain direct information about the backsteps of the motor. Our theory provides a unified description for the myosin V motor as studied in single motor experiments.}, language = {en} } @phdthesis{Swierczynski2012, author = {Swierczynski, Tina}, title = {A 7000 yr runoff chronology from varved sediments of Lake Mondsee (Upper Austria)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66702}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {The potential increase in frequency and magnitude of extreme floods is currently discussed in terms of global warming and the intensification of the hydrological cycle. The profound knowledge of past natural variability of floods is of utmost importance in order to assess flood risk for the future. Since instrumental flood series cover only the last ~150 years, other approaches to reconstruct historical and pre-historical flood events are needed. Annually laminated (varved) lake sediments are meaningful natural geoarchives because they provide continuous records of environmental changes > 10000 years down to a seasonal resolution. Since lake basins additionally act as natural sediment traps, the riverine sediment supply, which is preserved as detrital event layers in the lake sediments, can be used as a proxy for extreme discharge events. Within my thesis I examined a ~ 8.50 m long sedimentary record from the pre-Alpine Lake Mondsee (Northeast European Alps), which covered the last 7000 years. This sediment record consists of calcite varves and intercalated detrital layers, which range in thickness from 0.05 to 32 mm. Detrital layer deposition was analysed by a combined method of microfacies analysis via thin sections, Scanning Electron Microscopy (SEM), μX-ray fluorescence (μXRF) scanning and magnetic susceptibility. This approach allows characterizing individual detrital event layers and assigning a corresponding input mechanism and catchment. Based on varve counting and controlled by 14C age dates, the main goals of this thesis are (i) to identify seasonal runoff processes, which lead to significant sediment supply from the catchment into the lake basin and (ii) to investigate flood frequency under changing climate boundary conditions. This thesis follows a line of different time slices, presenting an integrative approach linking instrumental and historical flood data from Lake Mondsee in order to evaluate the flood record inferred from Lake Mondsee sediments. The investigation of eleven short cores covering the last 100 years reveals the abundance of 12 detrital layers. Therein, two types of detrital layers are distinguished by grain size, geochemical composition and distribution pattern within the lake basin. Detrital layers, which are enriched in siliciclastic and dolomitic material, reveal sediment supply from the Flysch sediments and Northern Calcareous Alps into the lake basin. These layers are thicker in the northern lake basin (0.1-3.9 mm) and thinner in the southern lake basin (0.05-1.6 mm). Detrital layers, which are enriched in dolomitic components forming graded detrital layers (turbidites), indicate the provenance from the Northern Calcareous Alps. These layers are generally thicker (0.65-32 mm) and are solely recorded within the southern lake basin. In comparison with instrumental data, thicker graded layers result from local debris flow events in summer, whereas thin layers are deposited during regional flood events in spring/summer. Extreme summer floods as reported from flood layer deposition are principally caused by cyclonic activity from the Mediterranean Sea, e.g. July 1954, July 1997 and August 2002. During the last two millennia, Lake Mondsee sediments reveal two significant flood intervals with decadal-scale flood episodes, during the Dark Ages Cold Period (DACP) and the transition from the Medieval Climate Anomaly (MCA) into the Little Ice Age (LIA) suggesting a linkage of transition to climate cooling and summer flood recurrences in the Northeastern Alps. In contrast, intermediate or decreased flood episodes appeared during the MWP and the LIA. This indicates a non-straightforward relationship between temperature and flood recurrence, suggesting higher cyclonic activity during climate transition in the Northeast Alps. The 7000-year flood chronology reveals 47 debris flows and 269 floods, with increased flood activity shifting around 3500 and 1500 varve yr BP (varve yr BP = varve years before present, before present = AD 1950). This significant increase in flood activity shows a coincidence with millennial-scale climate cooling that is reported from main Alpine glacier advances and lower tree lines in the European Alps since about 3300 cal. yr BP (calibrated years before present). Despite relatively low flood occurrence prior to 1500 varve yr BP, floods at Lake Mondsee could have also influenced human life in early Neolithic lake dwellings (5750-4750 cal. yr BP). While the first lake dwellings were constructed on wetlands, the later lake dwellings were built on piles in the water suggesting an early flood risk adaptation of humans and/or a general change of the Late Neolithic Culture of lake-dwellers because of socio-economic reasons. However, a direct relationship between the final abandonment of the lake dwellings and higher flood frequencies is not evidenced.}, language = {en} } @misc{Gassner2012, type = {Master Thesis}, author = {Gassner, Alexandra Carina}, title = {The character of the core-mantle boundary : a systematic study using PcP}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63590}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {Assuming that liquid iron alloy from the outer core interacts with the solid silicate-rich lower mantle the influence on the core-mantle reflected phase PcP is studied. If the core-mantle boundary is not a sharp discontinuity, this becomes apparent in the waveform and amplitude of PcP. Iron-silicate mixing would lead to regions of partial melting with higher density which in turn reduces the velocity of seismic waves. On the basis of the calculation and interpretation of short-period synthetic seismograms, using the reflectivity and Gauss Beam method, a model space is evaluated for these ultra-low velocity zones (ULVZs). The aim of this thesis is to analyse the behaviour of PcP between 10° and 40° source distance for such models using different velocity and density configurations. Furthermore, the resolution limits of seismic data are discussed. The influence of the assumed layer thickness, dominant source frequency and ULVZ topography are analysed. The Gr{\"a}fenberg and NORSAR arrays are then used to investigate PcP from deep earthquakes and nuclear explosions. The seismic resolution of an ULVZ is limited both for velocity and density contrasts and layer thicknesses. Even a very thin global core-mantle transition zone (CMTZ), rather than a discrete boundary and also with strong impedance contrasts, seems possible: If no precursor is observable but the PcP_model /PcP_smooth amplitude reduction amounts to more than 10\%, a very thin ULVZ of 5 km with a first-order discontinuity may exist. Otherwise, if amplitude reductions of less than 10\% are obtained, this could indicate either a moderate, thin ULVZ or a gradient mantle-side CMTZ. Synthetic computations reveal notable amplitude variations as function of the distance and the impedance contrasts. Thereby a primary density effect in the very steep-angle range and a pronounced velocity dependency in the wide-angle region can be predicted. In view of the modelled findings, there is evidence for a 10 to 13.5 km thick ULVZ 600 km south-eastern of Moscow with a NW-SE extension of about 450 km. Here a single specific assumption about the velocity and density anomaly is not possible. This is in agreement with the synthetic results in which several models create similar amplitude-waveform characteristics. For example, a ULVZ model with contrasts of -5\% VP , -15\% VS and +5\% density explain the measured PcP amplitudes. Moreover, below SW Finland and NNW of the Caspian Sea a CMB topography can be assumed. The amplitude measurements indicate a wavelength of 200 km and a height of 1 km topography, previously also shown in the study by Kampfmann and M{\"u}ller (1989). Better constraints might be provided by a joined analysis of seismological data, mineralogical experiments and geodynamic modelling.}, language = {en} } @article{Linck2013, author = {Linck, Barbara}, title = {Test items for and misconceptions of competences in the domain of logic programming}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {6}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64461}, pages = {25 -- 34}, year = {2013}, abstract = {Development of competence-oriented curricula is still an important theme in informatics education. Unfortunately informatics curricula, which include the domain of logic programming, are still input-orientated or lack detailed competence descriptions. Therefore, the development of competence model and of learning outcomes' descriptions is essential for the learning process in this domain. A prior research developed both. The next research step is to formulate test items to measure the described learning outcomes. This article describes this procedure and exemplifies test items. It also relates a test in school to the items and shows which misconceptions and typical errors are important to discuss in class. The test result can also confirm or disprove the competence model. Therefore, this school test is important for theoretical research as well as for the concrete planning of lessons. Quantitative analysis in school is important for evaluation and improvement of informatics education.}, language = {en} } @article{KimPark2013, author = {Kim, Seungyon and Park, Seongbin}, title = {Teaching NP completeness in secondary schools}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {6}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64476}, pages = {35 -- 38}, year = {2013}, abstract = {In this paper, we show how the theory of NP completeness can be introduced to students in secondary schools. The motivation of this research is that although there are difficult issues that require technical backgrounds, students are already familiar with demanding computational problems through games such as Sudoku or Tetris. Our intention is to bring together important concepts in the theory of NP completeness in such a way that students in secondary schools can easily understand them. This is part of our ongoing research about how to teach fundamental issues in Computer Science in secondary schools. We discuss what needs to be taught in which sequence in order to introduce ideas behind NP completeness to students without technical backgrounds.}, language = {en} } @article{Vaniček2013, author = {Van{\´i}ček, Jiř{\´i}}, title = {Introducing topics from informatics into primary school curricula}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {6}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64482}, pages = {41 -- 51}, year = {2013}, abstract = {The process of introducing compulsory ICT education at primary school level in the Czech Republic should be completed next year. Programming and Information, two topics from the basics of computer science have been included in a new textbook. The question is whether the new chapters of the textbook are comprehensible for primary school teachers, who have undergone no training in computer science. The paper reports on a pilot verification project in which pre-service primary school teachers were trained to teach these informatics topics.}, language = {en} } @book{OPUS4-6251, title = {Grammatica Grandonica}, editor = {Van Hal, Toon and Vielle, Christophe}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63218}, publisher = {Universit{\"a}t Potsdam}, pages = {280}, year = {2013}, abstract = {In May 2010, Johann Ernst Hanxleden's Grammatica Grandonica was rediscovered in Montecompatri (Lazio, Rome). Although historiographers attached much weight to the nearly oldest western grammar of Sanskrit, the precious manuscript was lost for several decades. The first aim of the present digital publication is to offer a photographical reproduction of the manuscript. This facsimile is accompanied by a double edition: a facing diplomatic edition with the Sanskrit in Malayāḷam script, followed by a transliterated established text.}, language = {en} } @phdthesis{Oey2008, author = {Oey, Melanie}, title = {Chloroplasts as bioreactors : high-yield production of active bacteriolytic protein antibiotics}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-28950}, school = {Universit{\"a}t Potsdam}, year = {2008}, abstract = {Plants, more precisely their chloroplasts with their bacterial-like expression machinery inherited from their cyanobacterial ancestors, can potentially offer a cheap expression system for proteinaceous pharmaceuticals. This system would be easily scalable and provides appropriate safety due to chloroplasts maternal inheritance. In this work, it was shown that three phage lytic enzymes (Pal, Cpl-1 and PlyGBS) could be successfully expressed at very high levels and with high stability in tobacco chloroplasts. PlyGBS expression reached an amount of foreign protein accumulation (> 70\% TSP) that has never been obtained before. Although the high expression levels of PlyGBS caused a pale green phenotype with retarded growth, presumably due to exhaustion of plastid protein synthesis capacity, development and seed production were not impaired under greenhouse conditions. Since Pal and Cpl-1 showed toxic effects when expressed in E. coli, a special plastid transformation vector (pTox) was constructed to allow DNA amplification in bacteria. The construction of the pTox transformation vector allowing a recombinase-mediated deletion of an E. coli transcription block in the chloroplast, leading to an increase of foreign protein accumulation to up to 40\% of TSP for Pal and 20\% of TSP for Cpl-1. High dose-dependent bactericidal efficiency was shown for all three plant-derived lytic enzymes using their pathogenic target bacteria S. pyogenes and S. pneumoniae. Confirmation of specificity was obtained for the endotoxic proteins Pal and Cpl-1 by application to E. coli cultures. These results establish tobacco chloroplasts as a new cost-efficient and convenient production platform for phage lytic enzymes and address the greatest obstacle for clinical application. The present study is the first report of lysin production in a non-bacterial system. The properties of chloroplast-produced lysins described in this work, their stability, high accumulation rate and biological activity make them highly attractive candidates for future antibiotics.}, language = {en} } @phdthesis{Regel2008, author = {Regel, Stefanie}, title = {The comprehension of figurative language : electrophysiological evidence on the processing of irony}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33376}, school = {Universit{\"a}t Potsdam}, year = {2008}, abstract = {Diese Dissertation untersucht das Verstehen figurativer Sprache, im Besonderen die zeitliche Verarbeitung von verbaler Ironie. In sechs Experimenten wurde mittels ereignis-korrelierter Potentiale (EKP) die Gehirnaktivit{\"a}t beim Verstehen ironischer {\"A}ußerungen im Vergleich zu entsprechenden nicht-ironischen {\"A}ußerungen gemessen und analysiert. Dar{\"u}berhinaus wurde der Einfluss verschiedener sprachbegleitender Hinweisreize, z.B. von Prosodie oder der Verwendung von Satzzeichen, sowie außersprachlicher Hinweisreize, wie bspw. pragmatischen Wissens, auf das Ironieverstehen untersucht. Auf Grundlage dieser Ergebnisse werden verschiedene psycholinguistische Modelle figurativer Sprachverarbeitung, d.h. 'standard pragmatic model', 'graded salience hypothesis', sowie 'direct access view', diskutiert.}, language = {en} } @inproceedings{GoltzPieth2010, author = {Goltz, Hans-Joachim and Pieth, Norbert}, title = {A tool for generating partition schedules of multiprocessor systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41556}, year = {2010}, abstract = {A deterministic cycle scheduling of partitions at the operating system level is supposed for a multiprocessor system. In this paper, we propose a tool for generating such schedules. We use constraint based programming and develop methods and concepts for a combined interactive and automatic partition scheduling system. This paper is also devoted to basic methods and techniques for modeling and solving this partition scheduling problem. Initial application of our partition scheduling tool has proved successful and demonstrated the suitability of the methods used.}, language = {en} } @inproceedings{Schrijvers2010, author = {Schrijvers, Tom}, title = {Overview of the monadic constraint programming framework}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41411}, year = {2010}, abstract = {A constraint programming system combines two essential components: a constraint solver and a search engine. The constraint solver reasons about satisfiability of conjunctions of constraints, and the search engine controls the search for solutions by iteratively exploring a disjunctive search tree defined by the constraint program. The Monadic Constraint Programming framework gives a monadic definition of constraint programming where the solver is defined as a monad threaded through the monadic search tree. Search and search strategies can then be defined as firstclass objects that can themselves be built or extended by composable search transformers. Search transformers give a powerful and unifying approach to viewing search in constraint programming, and the resulting constraint programming system is first class and extremely flexible.}, language = {en} } @phdthesis{Moerbt2010, author = {M{\"o}rbt, Nora}, title = {Differential proteome analysis of human lung epithelial cells following exposure to aromatic volatile organic compounds}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49257}, school = {Universit{\"a}t Potsdam}, year = {2010}, abstract = {The widespread usage of products containing volatile organic compounds (VOC) has lead to a general human exposure to these chemicals in work places or homes being suspected to contribute to the growing incidence of environmental diseases. Since the causal molecular mechanisms for the development of these disorders are not completely understood, the overall objective of this thesis was to investigate VOC-mediated molecular effects on human lung cells in vitro at VOC concentrations comparable to exposure scenarios below current occupational limits. Although differential expression of single proteins in response to VOCs has been reported, effects on complex protein networks (proteome) have not been investigated. However, this information is indispensable when trying to ascertain a mechanism for VOC action on the cellular level and establishing preventive strategies. For this study, the alveolar epithelial cell line A549 has been used. This cell line, cultured in a two-phase (air/liquid) model allows the most direct exposure and had been successfully applied for the analysis of inflammatory effects in response to VOCs. Mass spectrometric identification of 266 protein spots provided the first proteomic map of A549 cell line to this extent that may foster future work with this frequently used cellular model. The distribution of three typical air contaminants, monochlorobenzene (CB), styrene and 1,2 dichlorobenzene (1,2-DCB), between gas and liquid phase of the exposure model has been analyzed by gas chromatography. The obtained VOC partitioning was in agreement with available literature data. Subsequently the adapted in vitro system has been successfully employed to characterize the effects of the aromatic compound styrene on the proteome of A549 cells (Chapter 4). Initially, the cell toxicity has been assessed in order to ensure that most of the concentrations used in the following proteomic approach were not cytotoxic. Significant changes in abundance and phosphorylation in the total soluble protein fraction of A549 cells have been detected following styrene exposure. All proteins have been identified using mass spectrometry and the main cellular functions have been assigned. Validation experiments on protein and transcript level confirmed the results of the 2-DE experiments. From the results, two main cellular pathways have been identified that were induced by styrene: the cellular oxidative stress response combined with moderate pro-apoptotic signaling. Measurement of cellular reactive oxygen species (ROS) as well as the styrene-mediated induction of oxidative stress marker proteins confirmed the hypothesis of oxidative stress as the main molecular response mechanism. Finally, adducts of cellular proteins with the reactive styrene metabolite styrene 7,8 oxide (SO) have been identified. Especially the SO-adducts observed at both the reactive centers of thioredoxin reductase 1, which is a key element in the control of the cellular redox state, may be involved in styrene-induced ROS formation and apoptosis. A similar proteomic approach has been carried out with the halobenzenes CB and 1,2-DCB (Chapter 5). In accordance with previous findings, cell toxicity assessment showed enhanced toxicity compared to the one caused by styrene. Significant changes in abundance and phosphorylation of total soluble proteins of A549 cells have been detected following exposure to subtoxic concentrations of CB and 1,2-DCB. All proteins have been identified using mass spectrometry and the main cellular functions have been assigned. As for the styrene experiment, the results indicated two main pathways to be affected in the presence of chlorinated benzenes, cell death signaling and oxidative stress response. The strong induction of pro-apoptotic signaling has been confirmed for both treatments by detection of the cleavage of caspase 3. Likewise, the induction of redox-sensitive protein species could be correlated to an increased cellular level of ROS observed following CB treatment. Finally, common mechanisms in the cellular response to aromatic VOCs have been investigated (Chapter 6). A similar number (4.6-6.9\%) of all quantified protein spots showed differential expression (p<0.05) following cell exposure to styrene, CB or 1,2-DCB. However, not more than three protein spots showed significant regulation in the same direction for all three volatile compounds: voltage-dependent anion-selective channel protein 2, peroxiredoxin 1 and elongation factor 2. However, all of these proteins are important molecular targets in stress- and cell death-related signaling pathways.}, language = {en} } @book{PfauSteinbach2006, author = {Pfau, Roland and Steinbach, Markus}, title = {Modality-independent and modality-specific aspects of grammaticalization in sign languages}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-53-7}, issn = {1864-1857}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10886}, publisher = {Universit{\"a}t Potsdam}, pages = {97}, year = {2006}, abstract = {One type of internal diachronic change that has been extensively studied for spoken languages is grammaticalization whereby lexical elements develop into free or bound grammatical elements. Based on a wealth of spoken languages, a large amount of prototypical grammaticalization pathways has been identified. Moreover, it has been shown that desemanticization, decategorialization, and phonetic erosion are typical characteristics of grammaticalization processes. Not surprisingly, grammaticalization is also responsible for diachronic change in sign languages. Drawing data from a fair number of sign languages, we show that grammaticalization in visual-gestural languages - as far as the development from lexical to grammatical element is concerned - follows the same developmental pathways as in spoken languages. That is, the proposed pathways are modalityindependent. Besides these intriguing parallels, however, sign languages have the possibility of developing grammatical markers from manual and non-manual co-speech gestures. We will discuss various instances of grammaticalized gestures and we will also briefly address the issue of the modality-specificity of this phenomenon.}, language = {en} } @phdthesis{Ott2006, author = {Ott, Christian David}, title = {Stellar iron core collapse in {3+1} general relativity and the gravitational wave signature of core-collapse supernovae}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12986}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {I perform and analyse the first ever calculations of rotating stellar iron core collapse in {3+1} general relativity that start out with presupernova models from stellar evolutionary calculations and include a microphysical finite-temperature nuclear equation of state, an approximate scheme for electron capture during collapse and neutrino pressure effects. Based on the results of these calculations, I obtain the to-date most realistic estimates for the gravitational wave signal from collapse, bounce and the early postbounce phase of core collapse supernovae. I supplement my {3+1} GR hydrodynamic simulations with 2D Newtonian neutrino radiation-hydrodynamic supernova calculations focussing on (1) the late postbounce gravitational wave emission owing to convective overturn, anisotropic neutrino emission and protoneutron star pulsations, and (2) on the gravitational wave signature of accretion-induced collapse of white dwarfs to neutron stars.}, language = {en} } @misc{Hocking1996, author = {Hocking, Brian}, title = {Bridging boundaries: creating linkages : non-central governments and multilayered policy environments}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11126}, year = {1996}, abstract = {Observers of international politics have been conscious of the growing international involvement of non-central governments (NCGs), particularly in federal systems. These have been supplemented by the internationalisation of subnational actors in quasi-federal and even unitary states. One of the difficulties is that analysis has often been locked into the dominant paradigm debate in International Relations concerning who and who are not significant actors. Having briefly explored the nature of this changing environment, marked by a growing emphasis on access rather than control as a policy objective and the emergence of what is termed a 'catalytic diplomacy', the discussion focuses on the need for linkage between the levels of government in the pursuit of international as well as domestic policy goals. The nature of linkage mechanisms are discussed.}, language = {en} } @inproceedings{BergmannKopp2006, author = {Bergmann, Kirsten and Kopp, Stefan}, title = {Verbal or visual? : How information is distributed across speech and gesture in spatial dialog}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10375}, year = {2006}, abstract = {In spatial dialog like in direction giving humans make frequent use of speechaccompanying gestures. Some gestures convey largely the same information as speech while others complement speech. This paper reports a study on how speakers distribute meaning across speech and gesture, and depending on what factors. Utterance meaning and the wider dialog context were tested by statistically analyzing a corpus of direction-giving dialogs. Problems of speech production (as indicated by discourse markers and disfluencies), the communicative goals, and the information status were found to be influential, while feedback signals by the addressee do not have any influence.}, language = {en} } @inproceedings{Diderichsen2006, author = {Diderichsen, Philip}, title = {Cross recurrence quantification analysis of indefinite anaphora in Swedish dialog : an eye-tracking pilot experiment}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10388}, year = {2006}, abstract = {A new method is used in an eye-tracking pilot experiment which shows that it is possible to detect differences in common ground associated with the use of minimally different types of indefinite anaphora. Following Richardson and Dale (2005), cross recurrence quantification analysis (CRQA) was used to show that the tandem eye movements of two Swedish-speaking interlocutors are slightly more coupled when they are using fully anaphoric indefinite expressions than when they are using less anaphoric indefinites. This shows the potential of CRQA to detect even subtle processing differences in ongoing discourse.}, language = {en} } @inproceedings{LueckingRieserStaudacher2006, author = {L{\"u}cking, Andy and Rieser, Hannes and Staudacher, Marc}, title = {Multi-modal integration for gesture and speech}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10393}, year = {2006}, abstract = {Demonstratives, in particular gestures that "only" accompany speech, are not a big issue in current theories of grammar. If we deal with gestures, fixing their function is one big problem, the other one is how to integrate the representations originating from different channels and, ultimately, how to determine their composite meanings. The growing interest in multi-modal settings, computer simulations, human-machine interfaces and VRapplications increases the need for theories ofmultimodal structures and events. In our workshopcontribution we focus on the integration of multimodal contents and investigate different approaches dealing with this problem such as Johnston et al. (1997) and Johnston (1998), Johnston and Bangalore (2000), Chierchia (1995), Asher (2005), and Rieser (2005).}, language = {en} } @inproceedings{SagetGuyomard2006, author = {Saget, Sylvie and Guyomard, Marc}, title = {Goal-oriented dialog as a collaborative subordinated activity involving collective acceptance}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10420}, year = {2006}, abstract = {Modeling dialog as a collaborative activity consists notably in specifying the contain of the Conversational Common Ground and the kind of social mental state involved. In previous work (Saget, 2006), we claim that Collective Acceptance is the proper social attitude for modeling Conversational Common Ground in the particular case of goal-oriented dialog. We provide a formalization of Collective Acceptance, besides elements in order to integrate this attitude in a rational model of dialog are provided; and finally, a model of referential acts as being part of a collaborative activity is provided. The particular case of reference has been chosen in order to exemplify our claims.}, language = {en} } @inproceedings{DeVaultStone2006, author = {DeVault, David and Stone, Matthew}, title = {Scorekeeping in an uncertain language game}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10448}, year = {2006}, abstract = {Received views of utterance context in pragmatic theory characterize the occurrent subjective states of interlocutors using notions like common knowledge or mutual belief. We argue that these views are not compatible with the uncertainty and robustness of context-dependence in human–human dialogue. We present an alternative characterization of utterance context as objective and normative. This view reconciles the need for uncertainty with received intuitions about coordination and meaning in context, and can directly inform computational approaches to dialogue.}, language = {en} } @misc{HoffmannLonghurst1999, author = {Hoffmann, Arthur and Longhurst, Kerry}, title = {German strategic culture and the changing role of the Bundeswehr}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11448}, year = {1999}, abstract = {The article mobilises the concept of strategic culture in order to identify the impact of history upon contemporary security policy. The article will first look at the "wholesale construction" of a strategic culture after the Second World War in West Germany before exploring its impact upon security policy since the end of the Cold War in two areas: the Bundeswehr's out-of-area role and conscription. The central argument presented here is that the strategic culture of the former Federal Republic now writ large on to the new united Germany sets the context within which security policies are designed. This strategic culture, as will be argued, acts as both a facilitating and a restraining variable on behaviour, making certain policy options possible and others impossible.}, language = {en} } @misc{Archer1999, author = {Archer, Clive}, title = {The EU, security and the Baltic region}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11453}, year = {1999}, abstract = {The end of the cold war division of the Baltic Sea in 1989, and the three Baltic states' return to independence in 1991 created new opportunities for the decision-makers of the area, as well as new possibilities for fashioning security in the region. This article will examine the security debate affecting the Baltic Sea region in the post-cold war period, and in particular, the relevance of the European Union to that debate. The following section will examine various concepts of security relevant to the Baltic region; the third section looks at the EU and the Baltic area; and the last part deals with the implications that EU membership by the Baltic Sea states may have for the security of the Baltic Sea zone.}, language = {en} } @misc{RoellySortais2004, author = {Roelly, Sylvie and Sortais, Michel}, title = {Space-time asymptotics of an infinite-dimensional diffusion having a long- range memory}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6700}, year = {2004}, abstract = {We develop a cluster expansion in space-time for an infinite-dimensional system of interacting diffusions where the drift term of each diffusion depends on the whole past of the trajectory; these interacting diffusions arise when considering the Langevin dynamics of a ferromagnetic system submitted to a disordered external magnetic field.}, language = {en} } @misc{RoellyThieullen2005, author = {Roelly, Sylvie and Thieullen, Mich{\`e}le}, title = {Duality formula for the bridges of a Brownian diffusion : application to gradient drifts}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6710}, year = {2005}, abstract = {In this paper, we consider families of time Markov fields (or reciprocal classes) which have the same bridges as a Brownian diffusion. We characterize each class as the set of solutions of an integration by parts formula on the space of continuous paths C[0; 1]; R-d) Our techniques provide a characterization of gradient diffusions by a duality formula and, in case of reversibility, a generalization of a result of Kolmogorov.}, language = {en} } @inproceedings{KuhnertGuentnerKlannetal.2006, author = {Kuhnert, Matthias and G{\"u}ntner, Andreas and Klann, Mechthild and Martin Garrido, F. and Zillgens, Birgit}, title = {Methods for spatial pattern comparison in distributed hydrological modelling : [Poster]}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7160}, year = {2006}, abstract = {The rigorous development, application and validation of distributed hydrological models obligates to evaluate data in a spatially distributed way. In particular, spatial model predictions such as the distribution of soil moisture, runoff generating areas or nutrient-contributing areas or erosion rates, are to be assessed against spatially distributed observations. Also model inputs, such as the distribution of modelling units derived by GIS and remote sensing analyses, should be evaluated against groundbased observations of landscape characteristics. So far, however, quantitative methods of spatial field comparison have rarely been used in hydrology. In this paper, we present algorithms that allow to compare observed and simulated spatial hydrological data. The methods can be applied for binary and categorical data on regular grids. They comprise cell-by-cell algorithms, cell-neighbourhood approaches that account for fuzziness of location, and multi-scale algorithms that evaluate the similarity of spatial fields with changing resolution. All methods provide a quantitative measure of the similarity of two maps. The comparison methods are applied in two mountainous catchments in southern Germany (Brugga, 40 km2) and Austria (L{\"o}hnersbach, 16 km2). As an example of binary hydrological data, the distribution of saturated areas is analyzed in both catchments. For categorical data, vegetation zones that are associated with different runoff generation mechanisms are analyzed in the L{\"o}hnersbach. Mapped spatial patterns are compared to simulated patterns from terrain index calculations and from satellite image analysis. It is discussed how particular features of visual similarity between the spatial fields are captured by the quantitative measures, leading to recommendations on suitable algorithms in the context of evaluating distributed hydrological models.}, language = {en} } @misc{RoellyDaiPra2004, author = {Roelly, Sylvie and Dai Pra, Paolo}, title = {An existence result for infinite-dimensional Brownian diffusions with non- regular and non Markovian drift}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6684}, year = {2004}, abstract = {We prove in this paper an existence result for infinite-dimensional stationary interactive Brownian diffusions. The interaction is supposed to be small in the norm ||.||∞ but otherwise is very general, being possibly non-regular and non-Markovian. Our method consists in using the characterization of such diffusions as space-time Gibbs fields so that we construct them by space-time cluster expansions in the small coupling parameter.}, language = {en} } @inproceedings{WolskaKruijffKorbayova2006, author = {Wolska, Magdalena and Kruijff-Korbayov{\´a}, Ivana}, title = {Modeling anaphora in informal mathematical dialogue}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10455}, year = {2006}, abstract = {We analyze anaphoric phenomena in the context of building an input understanding component for a conversational system for tutoring mathematics. In this paper, we report the results of data analysis of two sets of corpora of dialogs on mathematical theorem proving. We exemplify anaphoric phenomena, identify factors relevant to anaphora resolution in our domain and extensions to the input interpretation component to support it.}, language = {en} } @inproceedings{KempsonCann2006, author = {Kempson, Ruth and Cann, Ronnie}, title = {Dialogue pressures and syntactic change}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10469}, year = {2006}, abstract = {On the basis of the Dynamic Syntax framework, this paper argues that the production pressures in dialogue determining alignment effects and given versus new informational effects also drive the shift from case-rich free word order systems without clitic pronouns into systems with clitic pronouns with rigid relative ordering. The paper introduces assumptions of Dynamic Syntax, in particular the building up of interpretation through structural underspecification and update, sketches the attendant account of production with close coordination of parsing and production strategies, and shows how what was at the Latin stage a purely pragmatic, production-driven decision about linear ordering becomes encoded in the clitics in theMedieval Spanish system which then through successive steps of routinization yield the modern systems with immediately pre-verbal fixed clitic templates.}, language = {en} } @techreport{Becker2004, type = {Working Paper}, author = {Becker, Ralf E.}, title = {Revisiting public investment}, issn = {0948-7549}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-9025}, year = {2004}, abstract = {The consumption equivalence method is the theoretical basis of public cost-benefit analysis. Consumption equivalence public capital prices are explicitly introduces in order to sufficiently care for the opportunity cost of public expenditure. This can solve the dispute about the social rate of discount within public cost-benefit analysis witch was generated on a criterion looking similar to the capital value formula, known as Lind's approach. The social rate of discount is liberated from opportunity costs considerations and the discounting away of the effects for future welfare vanishes. The corresponding question whether one should accept a positive value of the pure rate of social time preference is an old issue. Its current state between the prescriptive and descriptive view can also be interpreted as a consequence of the oversimplification of standard cost- benefit analysis. But apart from an economic self-process the pure rate of social time preference is also defined as a business-as-usual value of social distance discounting. Hence, a political choice has to be made about this rate which is free in principal.}, language = {en} } @techreport{Drechsler2005, type = {Working Paper}, author = {Drechsler, Denis}, title = {Unemployment in Germany and the Eurosclerosis debate}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-9036}, year = {2005}, abstract = {Many European countries have experienced a significant increase of unemployment in recent years. This paper reviews several theoretical models that try to explain this phenomenon. Predominantly, these models claim a link between the poor performance of European labor markets and the high level of market regulation. Commonly referred to as the Eurosclerosis debate, prominent approaches consider insider-outsider relationships, search-models, and the influence of hiring and firing costs on equilibrium employment. The paper presents empirical evidence of each model and studies the relevance of the identified rigidities as a determinant of high unemployment in Europe. Furthermore, a case study analyzes the unemployment problem in Germany and critically discusses new reform efforts. In particular this section analyzes whether the recently enacted Hartz reforms can induce higher employment.}, language = {en} } @techreport{Eberhardt2005, type = {Working Paper}, author = {Eberhardt, Bj{\"o}rn}, title = {Public pensions in the U.S.}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-9058}, year = {2005}, abstract = {Contents: The Public Old Age Insurance of the U.S. -Historical overview -Technical details -Individual equity and social adequacy The Economic Problem of Old Age -Risks and economic security -Old age, retirement, and idividual precaution -Insurance markets, market failures, and social insurance -Options for public pension systems The Problems of Social Security -The financial balance of OASDI -Causes of the long-run problems -Rates of return -Conclusion - The case for Social Security reform Proposed Remedies -Full, partial, or no privatization? -The President's Commission to Strengthen Social Security -Kotlikoff's Personal Security System -The Diamond-Orszag Three-Part plan}, language = {en} } @inproceedings{VlugterKnott2006, author = {Vlugter, Peter and Knott, Alistair}, title = {A multi-speaker dialogue system for computer-aided language learning}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10208}, year = {2006}, abstract = {The main topic of this paper is how to configure a dialogue system to support computer-aided language learning. The paper also serves to introduce our new multi-speaker dialogue system, and highlight some of its novel features.}, language = {en} } @misc{LoehmannsroebenBeckHildebrandtetal.2006, author = {L{\"o}hmannsr{\"o}ben, Hans-Gerd and Beck, Michael and Hildebrandt, Niko and Schm{\"a}lzlin, Elmar and van Dongen, Joost T.}, title = {New challenges in biophotonics : laser-based fluoroimmuno analysis and in-vivo optical oxygen monitoring}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10120}, year = {2006}, abstract = {Two examples of our biophotonic research utilizing nanoparticles are presented, namely laser-based fluoroimmuno analysis and in-vivo optical oxygen monitoring. Results of the work include significantly enhanced sensitivity of a homogeneous fluorescence immunoassay and markedly improved spatial resolution of oxygen gradients in root nodules of a legume species.}, subject = {Sauerstoff}, language = {en} } @misc{NiederkruegerSalbBecketal.2006, author = {Niederkr{\"u}ger, Matthias and Salb, Christian and Beck, Michael and Hildebrandt, Niko and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Marowsky, Gerd}, title = {Improvement of a fluorescence immunoassay with a compact diode-pumped solid state laser at 315 nm}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10150}, year = {2006}, abstract = {We demonstrate the improvement of fluorescence immunoassay (FIA) diagnostics in deploying a newly developed compact diode-pumped solid state (DPSS) laser with emission at 315 nm. The laser is based on the quasi-three-level transition in Nd:YAG at 946 nm. The pulsed operation is either realized by an active Q-switch using an electro-optical device or by introduction of a Cr4+:YAG saturable absorber as passive Q-switch element. By extra-cavity second harmonic generation in different nonlinear crystal media we obtained blue light at 473 nm. Subsequent mixing of the fundamental and the second harmonic in a β-barium-borate crystal provided pulsed emission at 315 nm with up to 20 μJ maximum pulse energy and 17 ns pulse duration. Substitution of a nitrogen laser in a FIA diagnostics system by the DPSS laser succeeded in considerable improvement of the detection limit. Despite significantly lower pulse energies (7 μJ DPSS laser versus 150 μJ nitrogen laser), in preliminary investigations the limit of detection was reduced by a factor of three for a typical FIA.}, subject = {Immunoassay}, language = {en} } @inproceedings{Karagjosova2006, author = {Karagjosova, Elena}, title = {Correction and acceptance by contrastive focus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10258}, year = {2006}, abstract = {An account is presented of the focus properties, common ground effect and dialogue behaviour of the accented German discourse marker "doch" and the accented sentence negation "nicht". It is argued that "doch" and "nicht" evoke as a focus alternative the logical complement of the proposition expressed by the sentence in which they occur, and that an analysis in terms of contrastive focus accounts for their effect on the common ground and their function in dialogue.}, language = {en} } @inproceedings{MacuraGinzburg2006, author = {Macura, Zoran and Ginzburg, Jonathan}, title = {Acquiring words across generations : introspectively or interactively?}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10408}, year = {2006}, abstract = {How does a shared lexicon arise in population of agents with differing lexicons, and how can this shared lexicon be maintained over multiple generations? In order to get some insight into these questions we present an ALife model in which the lexicon dynamics of populations that possess and lack metacommunicative interaction (MCI) capabilities are compared. We ran a series of experiments on multi-generational populations whose initial state involved agents possessing distinct lexicons. These experiments reveal some clear differences in the lexicon dynamics of populations that acquire words solely by introspection contrasted with populations that learn using MCI or using a mixed strategy of introspection and MCI. The lexicon diverges at a faster rate for an introspective population, eventually collapsing to one single form which is associated with all meanings. This contrasts sharply with MCI capable populations in which a lexicon is maintained, where every meaning is associated with a unique word. We also investigated the effect of increasing the meaning space and showed that it speeds up the lexicon divergence for all populations irrespective of their acquisition method.}, language = {en} } @inproceedings{Thomas2006, author = {Thomas, Kavita E.}, title = {Modelling Correction Signalled by "But" in Dialogue}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10308}, year = {2006}, abstract = {Claiming that cross-speaker "but" can signal correction in dialogue, we start by describing the types of corrections "but" can communicate by focusing on the Speech Act (SA) communicated in the previous turn and address the ways in which "but" can correct what is communicated. We address whether "but" corrects the proposition, the direct SA or the discourse relation communicated in the previous turn. We will also briefly address other relations signalled by cross-turn "but". After presenting a typology of the situations "but" can correct, we will address how these corrections can be modelled in the Information State model of dialogue, motivating this work by showing how it can be used to potentially avoid misunderstandings. We wrap up by showing how the model presented here updates beliefs in the Information State representation of the dialogue and can be used to facilitate response deliberation.}, language = {en} } @inproceedings{BeyssadeMarandin2006, author = {Beyssade, Claire and Marandin, Jean-Marie}, title = {From complex to simple speech acts : a bidimensional analysis of illocutionary}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10319}, year = {2006}, abstract = {We present a new analysis of illocutionary forces in dialogue. We analyze them as complex conversational moves involving two dimensions: what Speaker commits herself to and what she calls on Addressee to perform. We start from the analysis of speech acts such as confirmation requests or whimperatives, and extend the analysis to seemingly simple speech acts, such as statements and queries. Then, we show how to integrate our proposal in the framework of the Grammar for Conversation (Ginzburg, to app.), which is adequate for modelling agents' information states and how they get updated.}, language = {en} } @inproceedings{Hara2006, author = {Hara, Yurie}, title = {Question intonation and lexicalized bias expression}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10323}, year = {2006}, abstract = {This paper examines the interaction between different utterance types and the Japanese modal particle darou, and proposes that the decision-theoretic semantics accounts for the interaction among darou, sentence types and intonation.}, language = {en} } @inproceedings{ArtsteinPoesio2006, author = {Artstein, Ron and Poesio, Massimo}, title = {Identifying reference to abstract objects in dialogue}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10357}, year = {2006}, abstract = {In two experiments, many annotators marked antecedents for discourse deixis as unconstrained regions of text. The experiments show that annotators do converge on the identity of these text regions, though much of what they do can be captured by a simple model. Demonstrative pronouns are more likely than definite descriptions to be marked with discourse antecedents. We suggest that our methodology is suitable for the systematic study of discourse deixis.}, language = {en} } @inproceedings{LascaridesStone2006, author = {Lascarides, Alex and Stone, Matthew}, title = {Formal semantics for iconic gesture}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10330}, year = {2006}, abstract = {We present a formal analysis of iconic coverbal gesture. Our model describes the incomplete meaning of gesture that's derivable from its form, and the pragmatic reasoning that yields a more specific interpretation. Our formalism builds on established models of discourse interpretation to capture key insights from the descriptive literature on gesture: synchronous speech and gesture express a single thought, but while the form of iconic gesture is an important clue to its interpretation, the content of gesture can be resolved only by linking it to its context.}, language = {en} } @inproceedings{LueckingRieserStaudacher2006, author = {L{\"u}cking, Andy and Rieser, Hannes and Staudacher, Marc}, title = {SDRT and multi-modal situated communication}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10348}, year = {2006}, abstract = {Classical SDRT (Asher and Lascarides, 2003) discussed essential features of dialogue like adjacency pairs or corrections and up-dating. Recent work in SDRT (Asher, 2002, 2005) aims at the description of natural dialogue. We use this work to model situated communication, i.e. dialogue, in which sub-sentential utterances and gestures (pointing and grasping) are used as conventional modes of communication. We show that in addition to cognitive modelling in SDRT, capturing mental states and speech-act related goals, special postulates are needed to extract meaning out of contexts. Gestural meaning anchors Discourse Referents in contextually given domains. Both sorts of meaning are fused with the meaning of fragments to get at fully developed dialogue moves. This task accomplished, the standard SDRT machinery, tagged SDRSs, rhetorical relations, the up-date mechanism, and the Maximize Discourse Coherence constraint generate coherent structures. In sum, meanings from different verbal and non-verbal sources are assembled using extended SDRT to form coherent wholes.}, language = {en} } @inproceedings{KranstedtLueckingPfeifferetal.2006, author = {Kranstedt, Alfred and L{\"u}cking, Andy and Pfeiffer, Thies and Rieser, Hannes and Staudacher, Marc}, title = {Measuring and reconstructing pointing in visual contexts}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10362}, year = {2006}, abstract = {We describe an experiment to gather original data on geometrical aspects of pointing. In particular, we are focusing upon the concept of the pointing cone, a geometrical model of a pointing's extension. In our setting we employed methodological and technical procedures of a new type to integrate data from annotations as well as from tracker recordings. We combined exact information on position and orientation with rater's classifications. Our first results seem to challenge classical linguistic and philosophical theories of demonstration in that they advise to separate pointings from reference.}, language = {en} } @misc{KaafaraniWexStrehmeletal.2002, author = {Kaafarani, Bilal R. and Wex, Brigitte and Strehmel, Bernd and Neckers, Douglas C.}, title = {Structural concept for fluorinated Y-enynes with solvatochromic properties}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13168}, year = {2002}, abstract = {An approach to the development of fluorescent probes to follow polymerizations in situ using fluorinated cross-conjugated enediynes (Y-enynes) is reported. Different substitution patterns in the Y-enynes result in distinct solvatochromic behavior. β,β-Bis(phenylethynyl)pentafluorostyrene 7, which bears no donor substituents and only fluorine at the styrene moiety, shows no solvatochromism. Donor substituted β,β-bis(3,4,5-trimethoxyphenylethynyl) pentafluorostyrene 8 and β,β-bis(4-butyl-2,3,5,6-tetrafluorophenylethynyl)-3,4,5-trimethoxystyrene 9 exhibit solvatochromism upon change of solvent polarity. Y-enyne 8 showed the largest solvatochromic shift (94 nm bathochromic shift) upon changing solvent from cyclohexane to acetonitrile. A smaller solvatochromic response (44 nm bathochromic shift) was observed for 9. Lippert-Mataga treatment of 8 and 9 yields slopes of -10,800 and -6,400 cm -1, respectively. This corresponds to a change in dipole moment of 9.6 and 6.9 D, respectively. The solvatochromic behavior in 8 and 9 supports the formation of an intramolecular charge transfer (ICT) state. The low fluorescence quantum yields are caused by competitive double bond rotation. The fluorescence decay time of 9 decreases in methyltetrahydrofuran from 2.1 ns at 77 K to 0.11 ns at 200 K. Efficient single bond rotation in 9 was frozen at -50 °C in a configuration in which the trimethoxyphenyl ring is perpendicular to the fluorinated rings. 7-9 are photostable compounds. The X-ray structure of 7 shows it is not planar and that its conjugation is distorted. Y-enyne 7 stacks in the solid state showing coulombic, actetylene-arene, and fluorine-π interactions.}, language = {en} } @unpublished{WittKurthsKrauseetal.1994, author = {Witt, Annette and Kurths, J{\"u}rgen and Krause, F. and Fischer, K.}, title = {On the validity of a model for the reversals of the Earth's magnetic field}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13460}, year = {1994}, abstract = {We have used techniques of nonlinear dynamics to compare a special model for the reversals of the Earth's magnetic field with the observational data. Although this model is rather simple, there is no essential difference to the data by means of well-known characteristics, such as correlation function and probability distribution. Applying methods of symbolic dynamics we have found that the considered model is not able to describe the dynamical properties of the observed process. These significant differences are expressed by algorithmic complexity and Renyi information.}, language = {en} } @unpublished{KurthsVossWittetal.1994, author = {Kurths, J{\"u}rgen and Voss, A. and Witt, Annette and Saparin, P. and Kleiner, H. J. and Wessel, Niels}, title = {Quantitative analysis of heart rate variability}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13470}, year = {1994}, abstract = {In the modern industrialized countries every year several hundred thousands of people die due to the sudden cardiac death. The individual risk for this sudden cardiac death cannot be defined precisely by common available, non-invasive diagnostic tools like Holter-monitoring, highly amplified ECG and traditional linear analysis of heart rate variability (HRV). Therefore, we apply some rather unconventional methods of nonlinear dynamics to analyse the HRV. Especially, some complexity measures that are basing on symbolic dynamics as well as a new measure, the renormalized entropy, detect some abnormalities in the HRV of several patients who have been classified in the low risk group by traditional methods. A combination of these complexity measures with the parameters in the frequency domain seems to be a promising way to get a more precise definition of the individual risk. These findings have to be validated by a representative number of patients.}, language = {en} } @phdthesis{Rust2007, author = {Rust, Henning}, title = {Detection of long-range dependence : applications in climatology and hydrology}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13347}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {It is desirable to reduce the potential threats that result from the variability of nature, such as droughts or heat waves that lead to food shortage, or the other extreme, floods that lead to severe damage. To prevent such catastrophic events, it is necessary to understand, and to be capable of characterising, nature's variability. Typically one aims to describe the underlying dynamics of geophysical records with differential equations. There are, however, situations where this does not support the objectives, or is not feasible, e.g., when little is known about the system, or it is too complex for the model parameters to be identified. In such situations it is beneficial to regard certain influences as random, and describe them with stochastic processes. In this thesis I focus on such a description with linear stochastic processes of the FARIMA type and concentrate on the detection of long-range dependence. Long-range dependent processes show an algebraic (i.e. slow) decay of the autocorrelation function. Detection of the latter is important with respect to, e.g. trend tests and uncertainty analysis. Aiming to provide a reliable and powerful strategy for the detection of long-range dependence, I suggest a way of addressing the problem which is somewhat different from standard approaches. Commonly used methods are based either on investigating the asymptotic behaviour (e.g., log-periodogram regression), or on finding a suitable potentially long-range dependent model (e.g., FARIMA[p,d,q]) and test the fractional difference parameter d for compatibility with zero. Here, I suggest to rephrase the problem as a model selection task, i.e.comparing the most suitable long-range dependent and the most suitable short-range dependent model. Approaching the task this way requires a) a suitable class of long-range and short-range dependent models along with suitable means for parameter estimation and b) a reliable model selection strategy, capable of discriminating also non-nested models. With the flexible FARIMA model class together with the Whittle estimator the first requirement is fulfilled. Standard model selection strategies, e.g., the likelihood-ratio test, is for a comparison of non-nested models frequently not powerful enough. Thus, I suggest to extend this strategy with a simulation based model selection approach suitable for such a direct comparison. The approach follows the procedure of a statistical test, with the likelihood-ratio as the test statistic. Its distribution is obtained via simulations using the two models under consideration. For two simple models and different parameter values, I investigate the reliability of p-value and power estimates obtained from the simulated distributions. The result turned out to be dependent on the model parameters. However, in many cases the estimates allow an adequate model selection to be established. An important feature of this approach is that it immediately reveals the ability or inability to discriminate between the two models under consideration. Two applications, a trend detection problem in temperature records and an uncertainty analysis for flood return level estimation, accentuate the importance of having reliable methods at hand for the detection of long-range dependence. In the case of trend detection, falsely concluding long-range dependence implies an underestimation of a trend and possibly leads to a delay of measures needed to take in order to counteract the trend. Ignoring long-range dependence, although present, leads to an underestimation of confidence intervals and thus to an unjustified belief in safety, as it is the case for the return level uncertainty analysis. A reliable detection of long-range dependence is thus highly relevant in practical applications. Examples related to extreme value analysis are not limited to hydrological applications. The increased uncertainty of return level estimates is a potentially problem for all records from autocorrelated processes, an interesting examples in this respect is the assessment of the maximum strength of wind gusts, which is important for designing wind turbines. The detection of long-range dependence is also a relevant problem in the exploration of financial market volatility. With rephrasing the detection problem as a model selection task and suggesting refined methods for model comparison, this thesis contributes to the discussion on and development of methods for the detection of long-range dependence.}, language = {en} } @unpublished{ThiessenhusenEspositoKurthsetal.1995, author = {Thiessenhusen, Kai-Uwe and Esposito, Larry W. and Kurths, J{\"u}rgen and Spahn, Frank}, title = {Detection of hidden resonances in Saturn's B-ring}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13618}, year = {1995}, abstract = {The Voyager 2 Photopolarimeter experiment has yielded the highest resolved data of Saturn's rings, exhibiting a wide variety of features. The B-ring region between 105000 km and 110000 km distance from Saturn has been investigated. It has a high matter density and contains no significance features visible by eye. Analysis with statistical methods has let us to the detection of two significant events. These features are correlated with the inner 3:2 resonances of the F-ring shepherd satellites Pandora and Prometheus, and may be evidence of large ring paricles caught in the corotation resonances.}, language = {en} } @misc{DoscheMicklerLoehmannsroebenetal.2007, author = {Dosche, Carsten and Mickler, Wulfhard and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Agenet, Nicolas and Vollhardt, K. Peter C.}, title = {Photoinduced electron transfer in [N]phenylenes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12463}, year = {2007}, abstract = {First studies of electron transfer in [N]phenylenes were performed in bimolecular quenching reactions of angular [3]- and triangular [4]phenylene with various electron acceptors. The relation between the quenching rate constants kq and the free energy change of the electron transfer (ΔG0CS ) could be described by the Rehm-Weller equation. From the experimental results, a reorganization energy λ of 0.7 eV was derived. Intramolecular electron transfer reactions were studied in an [N]phenylene bichomophore and a corresponding reference compound. Fluorescence lifetime and quantum yield of the bichromophor display a characteristic dependence on the solvent polarity, whereas the corresponding values of the reference compound remain constant. From the results, a nearly isoenergonic ΔG0CS can be determined. As the triplet quantum yield is nearly independent of the polarity, charge recombination leads to the population of the triplet state.}, language = {en} } @phdthesis{Demircioglu2007, author = {Demircioglu, Aydin}, title = {Reconstruction of deligne classes and cocycles}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13755}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {In der vorliegenden Arbeit verallgemeinern wir im Wesentlichen zwei Theoreme von Mackaay-Picken und Picken (2002, 2004). Im ihrem Artikel zeigen Mackaay und Picken,dass es eine bijektive Korrespodenz zwischen Deligne 2-Klassen \$\xi \in \check{H}^2(M, \mathcal{D}^2)\$ und Holonomie Abbildungen von der zweiten d{\"u}nnen Homotopiegruppe \$\pi_2^2(M)\$ in die abelsche Gruppe \$U(1)\$ gibt. Im zweiten Artikel wird eine Verallgemeinerung dieses Theorems bewiesen: Picken zeigt, dass es eine Bijektion gibt zwischen Deligne 2-Kozykeln und gewissen 2-dimensionalen topologischen Quantenfeldtheorien. In dieser Arbeit zeigen wir, dass diese beiden Theoreme in allen Dimensionen gelten.Wir betrachten zun{\"a}chst den Holonomie Fall und k{\"o}nnen mittels simplizialen Methoden nachweisen, dass die Gruppe der glatten Deligne \$d\$-Klassen isomorph ist zu der Gruppe der glatten Holonomie Abbildungen von der \$d\$-ten d{\"u}nnen Homotopiegruppe \$\pi_d^d(M)\$ nach \$U(1)\$, sofern \$M\$ eine \$(d-1)\$-zusammenh{\"a}ngende Mannigfaltigkeit ist. Wir vergleichen dieses Resultat mit einem Satz von Gajer (1999). Gajer zeigte, dass jede Deligne \$d\$-Klasse durch eine andere Klasse von Holonomie-Abbildungen rekonstruiert werden kann, die aber nicht nur Holonomien entlang von Sph{\"a}ren, sondern auch entlang von allgemeinen \$d\$-Mannigfaltigkeiten in \$M\$ enth{\"a}lt. Dieser Zugang ben{\"o}tigt dann aber nicht, dass \$M\$ hoch-zusammenh{\"a}ngend ist. Wir zeigen, dass im Falle von flachen Deligne \$d\$-Klassen unser Rekonstruktionstheorem sich von Gajers unterscheidet, sofern \$M\$ nicht als \$(d-1)\$, sondern nur als \$(d-2)\$-zusammenh{\"a}ngend angenommen wird. Stiefel Mannigfaltigkeiten besitzen genau diese Eigenschaft, und wendet man unser Theorem auf diese an und vergleicht das Resultat mit dem von Gajer, so zeigt sich, dass es zuviele Deligne Klassen rekonstruiert. Dies bedeutet, dass unser Rekonstruktionsthreorem ohne die Zusatzbedingungen an die Mannigfaltigkeit M nicht auskommt, d.h. unsere Rekonstruktion ben{\"o}tigt zwar weniger Informationen {\"u}ber die Holonomie entlang von d-dimensionalen Mannigfaltigkeiten, aber daf{\"u}r muss M auch \$(d-1)\$-zusammenh{\"a}ngend angenommen werden. Wir zeigen dann, dass auch das zweite Theorem verallgemeinert werden kann: Indem wir das Konzept einer Picken topologischen Quantenfeldtheorie in beliebigen Dimensionen einf{\"u}hren, k{\"o}nnen wir nachweisen, dass jeder Deligne \$d\$-Kozykel eine solche \$d\$-dimensionale Feldtheorie mit zwei besonderen Eigenschaften, der d{\"u}nnen Invarianz und der Glattheit, induziert. Wir beweisen, dass jede \$d\$-dimensionale topologische Quantenfeldtheorie nach Picken mit diesen zwei Eigenschaften auch eine Deligne \$d\$-Klasse definiert und pr{\"u}fen nach, dass diese Konstruktion sowohl surjektiv als auch injektiv ist. Demzufolge sind beide Gruppen isomorph.}, language = {en} } @inproceedings{MillsHealey2006, author = {Mills, Gregory J. and Healey, Patrick G. T.}, title = {Clarifying spatial descriptions : local and global effects on semantic co-ordination}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10414}, year = {2006}, abstract = {A key problem for models of dialogue is to explain the mechanisms involved in generating and responding to clarification requests. We report a 'Maze task' experiment that investigates the effect of 'spoof' clarification requests on the development of semantic co-ordination. The results provide evidence of both local and global semantic co-ordination phenomena that are not captured by existing dialogue co-ordination models.}, language = {en} } @inproceedings{DzikovskaCallawayStoneetal.2006, author = {Dzikovska, Myroslava O. and Callaway, Charles B. and Stone, Matthew and Moore, Johanna D.}, title = {Understanding student input for tutorial dialogue in procedural domains}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10193}, year = {2006}, abstract = {We present an analysis of student language input in a corpus of tutoring dialogue in the domain of symbolic differentiation. Our focus on procedural tutoring makes the dialogue comparable to collaborative problem-solving (CPS). Existing CPS models describe the process of negotiating plans and goals, which also fits procedural tutoring. However, we provide a classification of student utterances and corpus annotation which shows that approximately 28\% of non-trivial student language in this corpus is not accounted for by existing models, and addresses other functions, such as evaluating past actions or correcting mistakes. Our analysis can be used as a foundation for improving models of tutoring dialogue.}, language = {en} } @misc{PueschelOppermannMuscholetal.1989, author = {P{\"u}schel, Gerhard Paul and Oppermann, Martin and Muschol, Waldemar and G{\"o}tze, Otto and Jungermann, Kurt}, title = {Increase of glucose and lactate output and decrease of flow by human anaphylatoxin C3a but not C5a in perfused rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16733}, year = {1989}, abstract = {The complement fragments C3a and C5a were purified from zymosan-activated human serum by column chromatographic procedures after the bulk of the proteins had been removed by acidic polyethylene glycol precipitation. In the isolated in situ perfused rat liver C3a increased glucose and lactate output and reduced flow. Its effects were enhanced in the presence of the carboxypeptidase inhibitor DL-mercaptomethyl-3-guanidinoethylthio-propanoic acid (MERGETPA) and abolished by preincubation of the anaphylatoxin with carboxypeptidase B or with Fab fragments of an anti-C3a monoclonal antibody. The C3a effects were partially inhibited by the thromboxane antagonist BM13505. C5a had no effect. It is concluded that locally but not systemically produced C3a may play an important role in the regulation of local metabolism and hemodynamics during inflammatory processes in the liver.}, language = {en} } @book{SkopeteasFiedlerHellmuthetal.2006, author = {Skopeteas, Stavros and Fiedler, Ines and Hellmuth, Sam and Schwarz, Anne and Stoel, Ruben and Fanselow, Gisbert and F{\´e}ry, Caroline and Krifka, Manfred}, title = {Questionnaire on information structure (OUIS): reference manual}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-14-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12413}, publisher = {Universit{\"a}t Potsdam}, pages = {263}, year = {2006}, abstract = {Contents: Chapter 1. Introduction 1 Information Structure 2 Grammatical Correlates of Information Structure 3 Structure of the Questionnaire 4 Experimental Tasks 5 Technicalities 6 Archiving 7 Acknowledgments Chapter 2. General Questions 1 General Information 2 Phonology 3 Morphology and Syntax Chapter 3. Experimental tasks 1 Changes (Given/New in Intransitives and Transitives) 2 Giving (Given/New in Ditransitives) 3 Visibility (Given/New, Animacy and Type/Token Reference) 4 Locations (Given/New in Locative Expressions) 5 Sequences (Given/New/Contrast in Transitives) 6 Dynamic Localization (Given/New in Dynamic Loc. Descriptions) 7 Birthday Party (Weight and Discourse Status) 8 Static Localization (Macro-Planning and Given/New in Locatives) 9 Guiding (Presentational Utterances) 10 Event Cards (All New) 11 Anima (Focus types and Animacy) 12 Contrast (Contrast in pairing events) 13 Animal Game (Broad/Narrow Focus in NP) 14 Properties (Focus on Property and Possessor) 15 Eventives (Thetic and Categorical Utterances) 16 Tell a Story (Contrast in Text) 17 Focus Cards (Selective, Restrictive, Additive, Rejective Focus) 18 Who does What (Answers to Multiple Constituent Questions) 19 Fairy Tale (Topic and Focus in Coherent Discourse) 20 Map Task (Contrastive and Selective Focus in Spontaneous Dialogue) 21 Drama (Contrastive Focus in Argumentation) 22 Events in Places (Spatial, Temporal and Complex Topics) 23 Path Descriptions (Topic Change in Narrative) 24 Groups (Partial Topic) 25 Connections (Bridging Topic) 26 Indirect (Implicational Topic) 27 Surprises (Subject-Topic Interrelation) 28 Doing (Action Given, Action Topic) 29 Influences (Question Priming) Chapter 4. Translation tasks 1 Basic Intonational Properties 2 Focus Translation 3 Topic Translation 4 Quantifiers Chapter 5. Information structure summary survey 1 Preliminaries 2 Syntax 3 Morphology 4 Prosody 5 Summary: Information structure Chapter 6. Performance of Experimental Tasks in the Field 1 Field sessions 2 Field Session Metadata 3 Informants' Agreement}, language = {en} } @inproceedings{BoegelButtHautlietal.2008, author = {B{\"o}gel, Tina and Butt, Miriam and Hautli, Annette and Sulger, Sebastian}, title = {Developing a finite-state morphological analyzer for Urdu and Hindi}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27155}, year = {2008}, abstract = {We introduce and discuss a number of issues that arise in the process of building a finite-state morphological analyzer for Urdu, in particular issues with potential ambiguity and non-concatenative morphology. Our approach allows for an underlyingly similar treatment of both Urdu and Hindi via a cascade of finite-state transducers that transliterates the very different scripts into a common ASCII transcription system. As this transliteration system is based on the XFST tools that the Urdu/Hindi common morphological analyzer is also implemented in, no compatibility problems arise.}, language = {en} } @inproceedings{YliJyrae2008, author = {Yli-Jyr{\"a}, Anssi}, title = {Applications of diamonded double negation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27109}, year = {2008}, abstract = {Nested complementation plays an important role in expressing counter- i.e. star-free and first-order definable languages and their hierarchies. In addition, methods that compile phonological rules into finite-state networks use double-nested complementation or "double negation". This paper reviews how the double-nested complementation extends to a relatively new operation, generalized restriction (GR), coined by the author (Yli-Jyr{\"a} and Koskenniemi 2004). This operation encapsulates a double-nested complementation and elimination of a concatenation marker, diamond, whose finite occurrences align concatenations in the arguments of the operation. The paper demonstrates that the GR operation has an interesting potential in expressing regular languages, various kinds of grammars, bimorphisms and relations. This motivates a further study of optimized implementation of the operator.}, language = {en} } @inproceedings{BarbaianiCanceddaDanceetal.2008, author = {Barbaiani, Mădălina and Cancedda, Nicola and Dance, Chris and Fazekas, Szil{\´a}rd and Ga{\´a}l, Tam{\´a}s and Gaussier, {\´E}ric}, title = {Asymmetric term alignment with selective contiguity constraints by multi-tape automata}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27115}, year = {2008}, abstract = {This article describes a HMM-based word-alignment method that can selectively enforce a contiguity constraint. This method has a direct application in the extraction of a bilingual terminological lexicon from a parallel corpus, but can also be used as a preliminary step for the extraction of phrase pairs in a Phrase-Based Statistical Machine Translation system. Contiguous source words composing terms are aligned to contiguous target language words. The HMM is transformed into a Weighted Finite State Transducer (WFST) and contiguity constraints are enforced by specific multi-tape WFSTs. The proposed method is especially suited when basic linguistic resources (morphological analyzer, part-of-speech taggers and term extractors) are available for the source language only.}, language = {en} } @inproceedings{Karttunen2008, author = {Karttunen, Lauri}, title = {New features in PARC finite state toolkits (Abstract)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27085}, year = {2008}, language = {en} } @misc{ElsenbeerCasselCastro1992, author = {Elsenbeer, Helmut and Cassel, Keith and Castro, Jorge}, title = {Spatial analysis of soil hydraulic conductivity in a tropical rain forest catchment}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16979}, year = {1992}, abstract = {The topography of first-order catchments in a region of western Amazonia was found to exhibit distinctive, recurrent features: a steep, straight lower side slope, a flat or nearly flat terrace at an intermediate elevation between valley floor and interfluve, and an upper side slope connecting interfluve and intermediate terrace. A detailed survey of soil-saturated hydraulic conductivity (K sat)-depth relationships, involving 740 undisturbed soil cores, was conducted in a 0.75-ha first-order catchment. The sampling approach was stratified with respect to the above slope units. Exploratory data analysis suggested fourth-root transformation of batches from the 0-0.1 m depth interval, log transformation of batches from the subsequent 0.1 m depth increments, and the use of robust estimators of location and scale. The K sat of the steep lower side slope decreased from 46 to 0.1 mm/h over the overall sampling depth of 0.4 m. The corresponding decrease was from 46 to 0.1 mm/h on the intermediate terrace, from 335 to 0.01 mm/h on the upper side slope, and from 550 to 0.015 mm/h on the interfluve. A depthwise comparison of these slope units led to the formulation of several hypotheses concerning the link between K sat and topography.}, language = {en} } @inproceedings{YliJyrae2008, author = {Yli-Jyr{\"a}, Anssi}, title = {Transducers from parallel replace rules and modes with generalized lenient composition}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27246}, year = {2008}, abstract = {Generalized Two-Level Grammar (GTWOL) provides a new method for compilation of parallel replacement rules into transducers. The current paper identifies the role of generalized lenient composition (GLC) in this method. Thanks to the GLC operation, the compilation method becomes bipartite and easily extendible to capture various application modes. In the light of three notions of obligatoriness, a modification to the compilation method is proposed. We argue that the bipartite design makes implementation of parallel obligatoriness, directionality, length and rank based application modes extremely easy, which is the main result of the paper.}, language = {en} } @inproceedings{Saleschus2008, author = {Sal{\´e}schus, Dirk}, title = {On resolving long distance dependencies in Russian verbs}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27235}, year = {2008}, abstract = {Morphological analyses based on word syntax approaches can encounter difficulties with long distance dependencies. The reason is that in some cases an affix has to have access to the inner structure of the form with which it combines. One solution is the percolation of features from ther inner morphemes to the outer morphemes with some process of feature unification. However, the obstacle of percolation constraints or stipulated features has lead some linguists to argue in favour of other frameworks such as, e.g., realizational morphology or parallel approaches like optimality theory. This paper proposes a linguistic analysis of two long distance dependencies in the morphology of Russian verbs, namely secondary imperfectivization and deverbal nominalization.We show how these processes can be reanalysed as local dependencies. Although finitestate frameworks are not bound by such linguistically motivated considerations, we present an implementation of our analysis as proposed in [1] that does not complicate the grammar or enlarge the network unproportionally.}, language = {en} } @inproceedings{IlarrazaGojenolaOronozetal.2008, author = {Ilarraza, Arantza D{\´i}az de and Gojenola, Koldo and Oronoz, Maite and Otaegi, Maialen and Alegria, I{\~n}aki}, title = {Syntactic error detection and correction in date expressions using finite-state transducers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27180}, year = {2008}, abstract = {This paper presents a system for the detection and correction of syntactic errors. It combines a robust morphosyntactic analyser and two groups of finite-state transducers specified using the Xerox Finite State Tool (xfst). One of the groups is used for the description of syntactic error patterns while the second one is used for the correction of the detected errors. The system has been tested on a corpus of real texts, containing both correct and incorrect sentences, with good results.}, language = {en} } @inproceedings{Fernando2008, author = {Fernando, Tim}, title = {Temporal propositions as regular languages}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27194}, year = {2008}, abstract = {Temporal propositions are mapped to sets of strings that witness (in a precise sense) the propositions over discrete linear Kripke frames. The strings are collected into regular languages to ensure the decidability of entailments given by inclusions between languages. (Various notions of bounded entailment are shown to be expressible as language inclusions.) The languages unwind computations implicit in the logical (and temporal) connectives via a system of finite-state constraints adapted from finite-state morphology. Applications to Hybrid Logic and non-monotonic inertial reasoning are briefly considered.}, language = {en} } @inproceedings{Didakowski2008, author = {Didakowski, J{\"o}rg}, title = {SynCoP : combining syntactic tagging with chunking using weighted finite state transducers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27172}, year = {2008}, abstract = {This paper describes the key aspects of the system SynCoP (Syntactic Constraint Parser) developed at the Berlin-Brandenburgische Akademie der Wissenschaften. The parser allows to combine syntactic tagging and chunking by means of constraint grammar using weighted finite state transducers (WFST). Chunks are interpreted as local dependency structures within syntactic tagging. The linguistic theories are formulated by criteria which are formalized by a semiring; these criteria allow structural preferences and gradual grammaticality. The parser is essentially a cascade of WFSTs. To find the most likely syntactic readings a best-path search is used.}, language = {en} } @inproceedings{ZarriessSeeker2008, author = {Zarrieß, Sina and Seeker, Wolfgang}, title = {Finite-state rule deduction for parsing non-constituent coordination}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27254}, year = {2008}, abstract = {In this paper, we present a finite-state approach to constituency and therewith an analysis of coordination phenomena involving so-called non-constituents. We show that non-constituents can be seen as parts of fully-fledged constituents and therefore be coordinated in the same way. We have implemented an algorithm based on finite state automata that generates an LFG grammar assigning valid analyses to non-constituent coordination structures in the German language.}, language = {en} }