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Asymptotic exit times
(2013)
Asymptotic transition times
(2013)
In this chapter, we introduce the deterministic Chafee-Infante equation. This equation has been the subject of intense research and is very well understood now. We recall some properties of its longtime dynamics and in particular the structure of its attractor. We then define reduced domains of attraction that will be fundamental in our study and give a result describing precisely the time that a solution starting form a reduced domain of attraction needs to reach a stable equilibrium. This result is then proved using the detailed knowledge of the attractor and classical tools such as the stable and unstable manifolds in a neighborhood of an equilibrium.
In this preparatory chapter, the tools of stochastic analysis needed for the investigation of the asymptotic behavior of the stochastic Chafee-Infante equation are provided. In the first place, this encompasses a recollection of basic facts about Lévy processes with values in Hilbert spaces. Playing the role of the additive noise processes perturbing the deterministic Chafee-Infante equation in the systems the stochastic dynamics of which will be our main interest, symmetric ?-stable Lévy processes are in the focus of our investigation (Sect. 3.1).
In this chapter, equipped with our previously obtained knowledge of exit and transition times in the limit of small noise amplitude ??0 , we shall investigate the global asymptotic behavior of our jump diffusion process in the time scale in which transitions occur, i.e. in the scale given by ?0(?)=?(1?Bc?(0)),?,?>0 . It turns out that in this time scale, the switching of the diffusion between neighborhoods of the stable solutions ? ± can be well described by a Markov chain jumping back and forth between two states with a characteristic Q-matrix determined by the quantities ?((D±0)c)?(Bc?(0)) as jumping rates.
Two end-member models have been proposed for the Paleogene Andean foreland: a simple W-E migrating foreland model and a broken-foreland model. We present new stratigraphic, sedimentological and structural data from the Paleogene Quebrada de los Colorados (QLC) Formation, in the Eastern Cordillera, with which to test these two different models. Basin-wide unconformities, growthstrata and changes in provenance indicate deposition of the QLC Formation in a tectonically active basin. Both west- and east-vergent structures, rooted in the basement, controlled the deposition and distribution of the QLC Formation from the Middle Eocene to the Early Miocene. The provenance analysis indicates that the main source areas were basement blocks, like the Paleozoic Oire Eruptive Complex, uplifted during Paleogene shortening, and that delimits the eastern boundary of the present-day intraorogenic Puna plateau. A comparison of the QLC sedimentary basin-fill pattern with those of adjacent Paleogene basins in the Puna plateau and in the Santa Barbara System highlights the presence of discrete depozones. These reflect the early compartmentalization of the foreland, rather than a stepwise advance of the deformation front of a thrust belt. The early Tertiary foreland of the southern central Andes is represented by a ca. 250-km-wide area comprising several deformation zones (Arizaro, Macon, Copalayo and Calchaqui) in which doubly vergent or asymmetric structures, rooted in the basement, were generated. Hence, classical foreland model is difficult to apply in this Paleogene basin; and our data and interpretation agree with a broken-foreland model.
We address the problem of belief change in (nonmonotonic) logic programming under answer set semantics. Our formal techniques are analogous to those of distance-based belief revision in propositional logic. In particular, we build upon the model theory of logic programs furnished by SE interpretations, where an SE interpretation is a model of a logic program in the same way that a classical interpretation is a model of a propositional formula. Hence we extend techniques from the area of belief revision based on distance between models to belief change in logic programs.
We first consider belief revision: for logic programs P and Q, the goal is to determine a program R that corresponds to the revision of P by Q, denoted P * Q. We investigate several operators, including (logic program) expansion and two revision operators based on the distance between the SE models of logic programs. It proves to be the case that expansion is an interesting operator in its own right, unlike in classical belief revision where it is relatively uninteresting. Expansion and revision are shown to satisfy a suite of interesting properties; in particular, our revision operators satisfy all or nearly all of the AGM postulates for revision.
We next consider approaches for merging a set of logic programs, P-1,...,P-n. Again, our formal techniques are based on notions of relative distance between the SE models of the logic programs. Two approaches are examined. The first informally selects for each program P-i those models of P-i that vary the least from models of the other programs. The second approach informally selects those models of a program P-0 that are closest to the models of programs P-1,...,P-n. In this case, P-0 can be thought of as a set of database integrity constraints. We examine these operators with regards to how they satisfy relevant postulate sets.
Last, we present encodings for computing the revision as well as the merging of logic programs within the same logic programming framework. This gives rise to a direct implementation of our approach in terms of off-the-shelf answer set solvers. These encodings also reflect the fact that our change operators do not increase the complexity of the base formalism.
Communicating location-specific information to pedestrians is a challenging task which can be aided by user-friendly digital technologies. In this paper, landmark visibility analysis, as a means for developing more usable pedestrian navigation systems, is discussed. Using an algorithmic framework for image-based 3D analysis, this method integrates a 3D city model with identified landmarks and produces raster visibility layers for each one. This output enables an Android phone prototype application to indicate the visibility of landmarks from the user's actual position. Tested in the field, the method achieves sufficient accuracy for the context of use and improves navigation efficiency and effectiveness.
We used the Linac Coherent Light Source free-electron x-ray laser to probe the electronic structure of CO molecules as their chemisorption state on Ru(0001) changes upon exciting the substrate by using a femtosecond optical laser pulse. We observed electronic structure changes that are consistent with a weakening of the CO interaction with the substrate but without notable desorption. A large fraction of the molecules (30%) was trapped in a transient precursor state that would precede desorption. We calculated the free energy of the molecule as a function of the desorption reaction coordinate using density functional theory, including van der Waals interactions. Two distinct adsorption wells-chemisorbed and precursor state separated by an entropy barrier-explain the anomalously high prefactors often observed in desorption of molecules from metals.
Psycholinguistic research shows that key properties of the human sentence processor are incrementality, connectedness (partial structures contain no unattached nodes), and prediction (upcoming syntactic structure is anticipated). There is currently no broad-coverage parsing model with these properties, however. In this article, we present the first broad-coverage probabilistic parser for PLTAG, a variant of TAG that supports all three requirements. We train our parser on a TAG-transformed version of the Penn Treebank and show that it achieves performance comparable to existing TAG parsers that are incremental but not predictive. We also use our PLTAG model to predict human reading times, demonstrating a better fit on the Dundee eye-tracking corpus than a standard surprisal model.
The adsorption of boron (boric acid) from aqueous solutions on alumina has been investigated at pH 8.0, I=0.1M NaClO4, T=22 +/- 3 degrees C, and under normal atmospheric conditions. The characterization of the adsorbed species was performed by Raman spectroscopy and the spectroscopic speciation was assisted by theoretical DFT calculations. Evaluation of the spectroscopic data points to the formation of inner-sphere surface complexes and indicates the formation of two different types of adsorbed boron species. The theoretical calculations corroborate the spectroscopic data and indicate that at low boron concentration the monodentate surface species dominates, whereas increased boron concentration favors the formation of a bidentate surface species. Assuming low coverage, the conditional formation constant for the monodentate surface species has been evaluated to be log=4.1 +/- 0.1.
1. Developing lesson plans and choosing strategies 2. The aims of the lesson plans in general 3. Strategies as a means to achieve theaims of the lesson plans 4. Evaluating the quality of lesson plans 5. Difficulties during lessons and adaptations afterwards 6. Student teachers’ overall feeling about their work 7. Using the strategies in future classes 8. Conclusion
During the last glacial period, the North Atlantic region experienced pronounced, millennial-scale alternations between cold, stadial conditions and milder interstadial conditions-commonly referred to as Dansgaard-Oeschger oscillations-as well as periods of massive iceberg discharge known as Heinrich events(1). Changes in Northern Hemisphere temperature, as recorded in Greenland(2-4), are thought to have affected the location of the Atlantic intertropical convergence zone(5,6) and the strength of the Indian summer monsoon(7,8). Here we use high-resolution records of sediment colour-a measure of terrigenous versus biogenic content-from the Cariaco Basin off the coast of Venezuela and the Arabian Sea to assess teleconnections with the North Atlantic climate system during the last glacial period. The Cariaco record indicates that the intertropical convergence zone migrated seasonally over the site during mild stadial conditions, but was permanently displaced south of the basin during peak stadials and Heinrich events. In the Arabian Sea, we find evidence of a weak Indian summer monsoon during the stadial events. The tropical records show a more variable response to North Atlantic cooling than the Greenland temperature records. We therefore suggest that Greenland climate is especially sensitive to variations in the North Atlantic system-in particular sea-ice extent-whereas the intertropical convergence zone and Indian monsoon system respond primarily to variations in mean Northern Hemisphere temperature.
Nonrelativistic electrostatic unmagnetized shocks are frequently observed in laboratory plasmas and they are likely to exist in astrophysical plasmas. Their maximum speed, expressed in units of the ion acoustic speed far upstream of the shock, depends only on the electron-to-ion temperature ratio if binary collisions are absent. The formation and evolution of such shocks is examined here for a wide range of shock speeds with particle-in-cell simulations. The initial temperatures of the electrons and the 400 times heavier ions are equal. Shocks form on electron time scales at Mach numbers between 1.7 and 2.2. Shocks with Mach numbers up to 2.5 form after tens of inverse ion plasma frequencies. The density of the shock-reflected ion beam increases and the number of ions crossing the shock thus decreases with an increasing Mach number, causing a slower expansion of the downstream region in its rest frame. The interval occupied by this ion beam is on a positive potential relative to the far upstream. This potential pre-heats the electrons ahead of the shock even in the absence of beam instabilities and decouples the electron temperature in the foreshock ahead of the shock from the one in the far upstream plasma. The effective Mach number of the shock is reduced by this electron heating. This effect can potentially stabilize nonrelativistic electrostatic shocks moving as fast as supernova remnant shocks.
The formation of unmagnetized electrostatic shock-like structures with a high Mach number is examined with one-and two-dimensional particle-in-cell (PIC) simulations. The structures are generated through the collision of two identical plasma clouds, which consist of equally hot electrons and ions with a mass ratio of 250. The Mach number of the collision speed with respect to the initial ion acoustic speed of the plasma is set to 4.6. This high Mach number delays the formation of such structures by tens of inverse ion plasma frequencies. A pair of stable shock-like structures is observed after this time in the 1D simulation, which gradually evolves into electrostatic shocks. The ion acoustic instability, which can develop in the 2D simulation but not in the 1D one, competes with the nonlinear process that gives rise to these structures. The oblique ion acoustic waves fragment their electric field. The transition layer, across which the bulk of the ions change their speed, widens and their speed change is reduced. Double layer-shock hybrid structures develop.
In articolul cu titlul "Identități hibride în comunitatea imigranților români" sunt prezentate rezultate parțiale precum și anumite analize a citatelor vorbitorilor din proiectul meu de doctorat cu titlul Sprachkontakt, Migration und Variation: Die frankophone Integration von Rumänen in Paris nach 1989. Lingvistica migratoare observă mișcările migranților români după căderea cortinei de fier. Aceștia au fost nevoiți să suporte consecințele managementului eronat al sistemului comunist. Între 1989 și 2012 mii de români au pǎrǎsit țara. Începând de atunci numărul imigranților români în Paris a crescut în mod significant. Scopul acestei contribuții este ilustrarea identității sociale a comunității migrante. În centrul lucrării se află descrierea procesului cultural și integrării lingvistice prin observarea dezvoltării a noi identități hibride.
The objectives of the present investigation are (i) to study the effects of climate change on precipitation extremes and (ii) to assess the uncertainty in the climate projections. The investigation is performed on the Lech catchment, located in the Northern Limestone Alps. In order to estimate the uncertainty in the climate projections, two statistical downscaling models as well as a number of global and regional climate models were considered. The downscaling models applied are the Expanded Downscaling (XDS) technique and the Long Ashton Research Station Weather Generator (LARS-WG). The XDS model, which is driven by analyzed or simulated large-scale synoptic fields, has been calibrated using ECMWF-interim reanalysis data and local station data. LARS-WG is controlled through stochastic parameters representing local precipitation variability, which are calibrated from station data only. Changes in precipitation mean and variability as simulated by climate models were then used to perturb the parameters of LARS-WG in order to generate climate change scenarios. In our study we use climate simulations based on the A1B emission scenario. The results show that both downscaling models perform well in reproducing observed precipitation extremes. In general, the results demonstrate that the projections are highly variable. The choice of both the GCM and the downscaling method are found to be essential sources of uncertainty. For spring and autumn, a slight tendency toward an increase in the intensity of future precipitation extremes is obtained, as a number of simulations show statistically significant increases in the intensity of 90th and 99th percentiles of precipitation on wet days as well as the 5- and 20-yr return values.
Effect of ionic strength and layer number on swelling of polyelectrolyte multilayers in water vapour
(2013)
The swelling behavior of polyelectrolyte multilayers (PEMs) of poly(sodium-4 styrene sulfonate) (PSS) and poly(diallyl dimethyl ammonium chloride) (PDADMAC) prepared from aqueous solution of 0.1 M and 0.5 M NaCl are investigated by ellipsometry and Atomic Force Microscopy (AFM). From 1 double-layer up to 4 double-layers of 0.1 M NaCl, the amount of swelling water in the PEMs decreases with increasing number of adsorbed double layers due to an increase in polyelectrolyte density as a result of the attraction between the positively charged outermost PDADMAC layer and the Si substrate. From 6 double layers to 30 double layers, the attraction is reduced due to a much larger distance between substrate and outermost layer leading to a much lower polyelectrolyte density and higher swelling water. In PEMs prepared from aqueous solution of 0.5 M NaCl, the amount of water constantly increases which is related to a monotonically decreasing polyelectrolyte density with increasing number of polyelectrolyte layers. Studies of the surface topology also indicate a transition from a more substrate affected interphase behavior to a continuum properties of the polyelectrolyte multilayers. The threshold for the transition from interphase to continuum behavior depends on the preparation conditions of the PEM.
Die multimedialen Informationsdienste im Internet werden immer umfangreicher und umfassender, wobei auch die nur in gedruckter Form vorliegenden Dokumente von den Bibliotheken digitalisiert und ins Netz gestellt werden. Über Online-Dokumentenverwaltungen oder Suchmaschinen können diese Dokumente gefunden und dann in gängigen Formaten wie z.B. PDF bereitgestellt werden. Dieser Artikel beleuchtet die Funktionsweise der Humboldt Digital Library, die seit mehr als zehn Jahren Dokumente von Alexander von Humboldt in englischer Übersetzung im Web als HDL (Humboldt Digital Library) kostenfrei zur Verfügung stellt. Anders als eine digitale Bibliothek werden dabei allerdings nicht nur digitalisierte Dokumente als Scan oder PDF bereitgestellt, sondern der Text als solcher und in vernetzter Form verfügbar gemacht. Das System gleicht damit eher einem Informationssystem als einer digitalen Bibliothek, was sich auch in den verfügbaren Funktionen zur Auffindung von Texten in unterschiedlichen Versionen und Übersetzungen, Vergleichen von Absätzen verschiedener Dokumente oder der Darstellung von Bilden in ihrem Kontext widerspiegelt. Die Entwicklung von dynamischen Hyperlinks auf der Basis der einzelnen Textabsätze der Humboldt‘schen Werke in Form von Media Assets ermöglicht eine Nutzung der Programmierschnittstelle von Google Maps zur geographischen wie auch textinhaltlichen Navigation. Über den Service einer digitalen Bibliothek hinausgehend, bietet die HDL den Prototypen eines mehrdimensionalen Informationssystems, das mit dynamischen Strukturen arbeitet und umfangreiche thematische Auswertungen und Vergleiche ermöglicht.
1. Porter strategic competitive analysis 2. A Porter analysis of the competitive advantage of banks in business lending and proprietary trading 3. Summary, competitive advantage of banks in business lending and proprietary trading 4. JPMorgan’s “London Whale” speculation 5. A common misapprehension about hedged positions in corporate debt 6. Conclusion
This paper focuses on two different strategies to incorporate gold nanoparticles (AuNPs) into the matrix of polyacrylamide (PAAm) hydrogels. Poly(ethyleneimine) (PEI) is used as both reducing and stabilizing agent for the formation of AuNPs. In addition, the influence of an ionic liquid (IL) (i.e., 1-ethyl-3-methylimidazolium ethylsulfate) on the stability of the nanoparticles and their immobilization in the hydrogel is investigated The results show that AuNPs surrounded by a shell containing PEI and IL, synthesized according to the one-pot approach, are much better immobilized within the PAAm hydrogel. Hereby, the IL is responsible for structural changes in the hydrogel as well as the improved stabilization and embedding of the AuNPs into the polymer gel matrix.
The M (w) 6.2 Baladeh earthquake occurred on 28 May 2004 in the Alborz Mountains, northern Iran. This earthquake was the first strong shock in this intracontinental orogen for which digital regional broadband data are available. The Baladeh event provides a rare opportunity to study fault geometry and ongoing deformation processes using modern seismological methods. A joint inversion for hypocentres and a velocity model plus a surface-wave group dispersion curve analysis were used to obtain an adapted velocity model, customised for mid- and long-period waveform modelling. Based on the new velocity model, regional waveform data of the mainshock and larger aftershocks (M (w) a parts per thousand yen3.3) were inverted for moment tensors. For the Baladeh mainshock, this included inversion for kinematic parameters. All analysed earthquakes show dominant thrust mechanisms at depths between 14 and 26 km, with NW-SE striking fault planes. The mainshock ruptured a 28A degrees south-dipping area of 24 x 21 km along a north-easterly direction. The rupture plane of the mainshock does not coincide with the aftershock distribution, neither in map view nor with respect to depth. The considered aftershocks form two main clusters. The eastern cluster is associated with the mainshock. The western cluster does not appear to be connected with the rupture plane of the mainshock but, instead, indicates a second activated fault plane dipping at 85A degrees towards the north.
BackgroundThe economic impact of drug-eluting stent (DES) in-stent restenosis (ISR) is substantial, highlighting the need for cost-effective treatment strategies.
HypothesisCompared to plain old balloon angioplasty (POBA) or repeat DES implantation, drug-coated balloon (DCB) angioplasty is a cost-effective therapy for DES-ISR.
MethodsA Markov state-transition model was used to compare DCB angioplasty with POBA and repeat DES implantation. Model input parameters were obtained from the literature, and the cost analysis was conducted from a German healthcare payer's perspective. Extensive sensitivity analyses were performed.
ResultsInitial procedure costs amounted to Euro3488 for DCB angioplasty and to Euro2782 for POBA. Over a 6-month time horizon, the DCB strategy was less costly (Euro4028 vs Euro4169) and more effective in terms of life-years (LYs) gained (0.497 versus 0.489) than POBA. The DES strategy incurred initial costs of Euro3167 and resulted in 0.494 LYs gained, at total costs of Euro4101 after a 6-month follow-up. Thus, DCB angioplasty was the least costly and most effective strategy. Base-case results were influenced mostly by initial procedure costs, target lesion revascularization rates, and the costs of dual antiplatelet therapy.
ConclusionsDCB angioplasty is a cost-effective treatment option for coronary DES-ISR. The higher initial costs of the DCB strategy compared to POBA or repeat DES implantation are offset by later cost savings.
Aims Recent studies have demonstrated the safety and efficacy of catheter-based renal sympathetic denervation (RDN) for the treatment of resistant hypertension. We aimed to determine the cost-effectiveness of this approach separately for men and women of different ages.
Methods and results A Markov state-transition model accounting for costs, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness was developed to compare RDN with best medical therapy (BMT) in patients with resistant hypertension. The model ran from age 30 to 100 years or death, with a cycle length of 1 year. The efficacy of RDN was modelled as a reduction in the risk of hypertension-related disease events and death. Analyses were conducted from a payer's perspective. Costs and QALYs were discounted at 3% annually. Both deterministic and probabilistic sensitivity analyses were performed. When compared with BMT, RDN gained 0.98 QALYs in men and 0.88 QALYs in women 60 years of age at an additional cost of (sic)2589 and (sic)2044, respectively. As the incremental cost-effectiveness ratios increased with patient age, RDN consistently yielded more QALYs at lower costs in lower age groups. Considering a willingness-to-pay threshold of (sic)35 000/QALY, there was a 95% probability that RDN would remain cost-effective up to an age of 78 and 76 years in men and women, respectively. Cost-effectiveness was influenced mostly by the magnitude of effect of RDN on systolic blood pressure, the rate of RDN non-responders, and the procedure costs of RDN.
Conclusion Renal sympathetic denervation is a cost-effective intervention for patients with resistant hypertension. Earlier treatment produces better cost-effectiveness ratios.
Collinearity a review of methods to deal with it and a simulation study evaluating their performance
(2013)
Collinearity refers to the non independence of predictor variables, usually in a regression-type analysis. It is a common feature of any descriptive ecological data set and can be a problem for parameter estimation because it inflates the variance of regression parameters and hence potentially leads to the wrong identification of relevant predictors in a statistical model. Collinearity is a severe problem when a model is trained on data from one region or time, and predicted to another with a different or unknown structure of collinearity. To demonstrate the reach of the problem of collinearity in ecology, we show how relationships among predictors differ between biomes, change over spatial scales and through time. Across disciplines, different approaches to addressing collinearity problems have been developed, ranging from clustering of predictors, threshold-based pre-selection, through latent variable methods, to shrinkage and regularisation. Using simulated data with five predictor-response relationships of increasing complexity and eight levels of collinearity we compared ways to address collinearity with standard multiple regression and machine-learning approaches. We assessed the performance of each approach by testing its impact on prediction to new data. In the extreme, we tested whether the methods were able to identify the true underlying relationship in a training dataset with strong collinearity by evaluating its performance on a test dataset without any collinearity. We found that methods specifically designed for collinearity, such as latent variable methods and tree based models, did not outperform the traditional GLM and threshold-based pre-selection. Our results highlight the value of GLM in combination with penalised methods (particularly ridge) and threshold-based pre-selection when omitted variables are considered in the final interpretation. However, all approaches tested yielded degraded predictions under change in collinearity structure and the folk lore'-thresholds of correlation coefficients between predictor variables of |r| >0.7 was an appropriate indicator for when collinearity begins to severely distort model estimation and subsequent prediction. The use of ecological understanding of the system in pre-analysis variable selection and the choice of the least sensitive statistical approaches reduce the problems of collinearity, but cannot ultimately solve them.
Silver nanoparticles (SNPs) are among the most commercialized nanoparticles because of their antibacterial effects. Besides being employed, e. g. as a coatingmaterial for sterile surfaces in household articles and appliances, the particles are also used in a broad range of medical applications. Their antibacterial properties make SNPs especially useful for wound disinfection or as a coating material for prostheses and surgical instruments. Because of their optical characteristics, the particles are of increasing interest in biodetection as well. Despite the widespread use of SNPs, there is little knowledge of their toxicity. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and laser post-ionization secondary neutral mass spectrometry (Laser-SNMS) were used to investigate the effects of SNPs on human macrophages derived from THP-1 cells in vitro. For this purpose, macrophages were exposed to SNPs. The SNP concentration ranges were chosen with regard to functional impairments of the macrophages. To optimize the analysis of the macrophages, a special silicon wafer sandwich preparation technique was employed; ToF-SIMS was employed to characterize fragments originating from macrophage cell membranes. With the use of this optimized sample preparation method, the SNP-exposed macrophages were analyzed with ToF-SIMS and with Laser-SNMS. With Laser-SNMS, the three-dimensional distribution of SNPs in cells could be readily detected with very high efficiency, sensitivity, and submicron lateral resolution. We found an accumulation of SNPs directly beneath the cell membrane in a nanoparticular state as well as agglomerations of SNPs inside the cells.
In einigen Bereichen der Informatiklehre ist es möglich, die persönlichen Erfahrungen der Studierenden im Umgang mit Informationstechnik aufzugreifen und vor dem Hintergrund theoretischer Konzepte aus der Literatur gemeinsam mit ihnen zu reflektieren. Das hier vorgestellte Lehrkonzept des Reflexionsdialogs erstreckt sich über drei Seminartermine und vorbereitende Selbstlernphasen. Unterstützt wird das Konzept durch DialogueMaps, eine Software zur Visualisierung komplexer Sachverhalte und zur Unterstützung interaktiver Dialoge. Dieser Beitrag beschreibt die Hintergründe des Lehrkonzeptes, das Lehrkonzept selbst sowie die inhaltliche Ausgestaltung im Rahmen eines Mastermoduls „Computergestützte Kooperation“.
As of the academic year 2010/2011, Berlin has a two-tier school system consisting of the Gymnasium (high school) and integrated secondary schools. On the basis of data provided by an ethnographically oriented research project, the authors examine the perception of this re-organization and the resulting challenges in a socio-economically weak district of Berlin. It becomes apparent that the equality of the two types of school repeatedly proclaimed in the educational-political discussion and usually grounded on the fact that, in principle, both schools provide the opportunity to achieve matriculation standard is primarily dependent on the conditions prevailing in the respective locations.
Invasive alien species pose a great threat to the integrity of natural communities by competition with and predation on native species. In Germany the invasive raccoon dog (Nyctereutes procyonoides) and the native red fox (Vulpes vulpes) occupy a similar ecological niche. Therefore, the aim of our study was to discover the extent of exploitative diet competition between these two generalist carnivores. Carcasses of red foxes (n=256) and raccoon dogs (n=253) were collected throughout Mecklenburg Western-Pomerania (north-east Germany) and stomachs contains were analysed. Frequency of occurrence and biomass share indicate that both canids are omnivorous and pursue opportunistic feeding strategies. Small mammals and edible plant material were the most important food resources for red foxes and raccoon dogs. Nonetheless, interspecies differences were recorded for edible plant material, small mammals and insects. While red foxes mostly feed on voles, raccoon dogs consumed mice and shrews as often as voles. Only raccoon dogs preyed on amphibians. There were no differences in carrion consumption, both species scavenged on wild boar and we found clear competition for carrion year-round. Moreover, there was evidence that two red foxes foraged on raccoon dogs and vice versa. The mean annual interspecies diet overlap index was relatively high. The diets determined for raccoon dogs and red foxes were quite similar and a similar food niche breadth was recorded. However, only minor competition is assumed to take place since differences in feeding habits do exist.
The main objective was to discover extent of interference and/or exploitative competition between the native red fox (Vulpes vulpes) and the introduced, invasive raccoon dog (Nyctereues proconoides) in the intensively used, agricultural landscape of northeast Germany (Mecklenburg-Western Pomerania) using very high frequency (VHF) radio telemetry. We recorded location data for 12 foxes and 16 raccoon dogs between July 2004 and December 2006. Species had similar average home range sizes estimated in each season (K95). Home ranges of adjacent raccoon dogs and foxes overlapped from 0.5 to 74.5 % with a mean of 26.4 %. We found a significantly different home range overlap index between the species showing that raccoon dog ranges shifted between seasons to a greater extent than red fox ranges. The raccoon dog differed significantly from the red fox in its use of habitat types, preferring dense vegetation cover and avoiding open areas. The red fox displayed less preference for or avoidance of specific habitat types. Moreover, an almost neutral inter-specific interaction index ranging from -0.12 to 0.12 indicates that raccoon dogs and red foxes ignored each other. It is concluded that widespread and available resources and differences in spatial use patterns prevent competition between red foxes and raccoon dogs in the agricultural landscape of northeast Germany.
This study examines patterns of climate variability by mapping shoreline changes between 1973 and 2008 for two shallow lakes in Malawi, East Africa. Multi-temporal LANDSAT data covering eight different years within the period of investigation were utilised for lake-area mapping, using image classification techniques. The approach was verified using simple comparisons with local rainfall data and satellite altimetry data. Results indicated that the lake areas varied between the different years investigated and that, although the lakes were affected by the same climate-forcing mechanisms, the individual basin characteristics had a critical effect on their responses. The most likely drivers for the climate-related shoreline variations are the El Nino/Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), causing synchronous changes to the water levels in both lakes, albeit showing differences in climate signal amplification.
The effect of student body composition on academic achievement International and National Evidence
(2013)
This paper reviews empirical evidence on the effect of the composition of a student body on academic achievement of students. After defining the term composition effect, methodological aspects regarding the study of composition effects are considered. International and national evidence for the composition of a student body with respect to students' abilities, social, and ethnic background is then presented. Whereas international studies find evidence for social, ethnic, and achievement composition variables, national studies reveal that mean achievement level of a school or class is the most important composition variable in Germany. However, this effect is confounded with school track and social composition, which itself exerts a small incremental effect. Ethnic composition, however, does not seem to play an important role. The paper closes with a presentation of the underlying processes of composition effects and a discussion on how the composition of a student body is considered in school governance practices.
The study investigates the effects of classroom composition (average ability, achievement, and socio-economic background, proportion of immigrant students) on the development in mathematics achievement, and reading literacy from grade 5 to 6. The study draws on a sample of N=1892 students in vocational track schools (Hauptschule) and intermediate track schools (Realschule) in Baden-Wuerttemberg, Germany. After controlling for school type, and between-school differences in student intake characteristics, none of the compositional characteristics showed a statistically significant effect on achievement development. School track was associated with the development of reading literacy even after controlling for individual differences; however, this relationship lost its statistical significance after the composition of the student body was additionally taken into account.
A series of 5-unsubstituted and 5-substituted 2-alkylidene-4-oxothiazolidine-S-oxides were synthesized by the sulfur-oxidation with m-CPBA. The stereochemistry of 5-substituted sulfoxides was determined by means of NMR spectroscopy and DFT theoretical calculations. It was found that the thermodynamically less stable anti-isomer was initially formed in the course of the oxidation, but it underwent epimerization to the mixture enriched in the more stable syn-isomer, during the work-up process. The higher stability of syn-isomers is ascribed to the stronger hyperconjugative sigma(C-H)->sigma*(S-O) interaction versus the weaker sigma(C-C)->sigma*(S-O) delocalization in their anti-counterparts and to the existence of intramolecular 1,5-CH center dot center dot center dot C hydrogen bonds.
Microorganisms such as Bacteria and Archaea play important roles in the Arctic food web and biogeochemical cycles. Nevertheless, knowledge of microbial community composition in Greenland waters is scarce, and information on microorganisms associated with Arctic zooplankton species is virtually non-existent. We compared free-living microbial communities with those associated with two key copepod species (Calanus finmarchicus and Metridia longa) along a salinity gradient from the deep waters beyond Fyllas Banke to the inner part of Godthabsfjord, West Greenland, in summer 2008. Using genetic fingerprinting we found that free-living Bacteria (in particular Alphaproteobacteria) and Archaea varied with environmental factors and formed different communities along the fjord. Microbial communities associated with the two copepod species were clearly different from those in the ambient water. Surprisingly, Archaea could not be detected on the copepods. Our results show that zooplankton form "microbial islands" in the Arctic pelagic realm with a distinctive community composition and presumably functionality different from the free-living Bacteria. Changes in intensity and timing of meltwater runoff due to global warming are expected to affect these microbial assemblages differently, with potentially significant ramifications for Arctic food webs and biogeochemistry.
Der traditionelle Weg in der Informatik besteht darin, Kompetenzen entweder normativ durch eine Expertengruppe festzulegen oder als Ableitungsergebnis eines Bildungsstandards aus einem externen Feld. Dieser Artikel stellt einen neuartigen und alternativen Ansatz vor, der sich der Methodik der Qualitativen Inhaltsanalyse (QI) bedient. Das Ziel war die Ableitung von informatischen Schlüsselkompetenzen anhand bereits etablierter und erprobter didaktischer Ansätze der Informatikdidaktik. Dazu wurde zunächst aus einer Reihe von Informatikdidaktikbüchern eine Liste mit möglichen Kandidaten für Kompetenzen generiert. Diese Liste wurde als QI-Kategoriensystem verwendet, mit der sechs verschiedene didaktische Ansätze analysiert wurden. Ein abschließender Verfeinerungsschritt erfolgte durch die Überprüfung, welche der gefundenen Kompetenzen in allen vier Kernbereichen der Informatik (theoretische, technische, praktische und angewandte Informatik) Anwendung finden. Diese Methode wurde für die informatische Schulausbildung exemplarisch entwickelt und umgesetzt, ist aber ebenfalls ein geeignetes Vorgehen für die Identifizierung von Schlüsselkompetenzen in anderen Gebieten, wie z. B. in der informatischen Hochschulausbildung, und soll deshalb hier kurz vorgestellt werden.
Zurzeit haben wir es mit der folgenden Situation an Universitäten zu tun: Studierende kommen mit unterschiedlichem Wissen und Kompetenzen zur Universität, um informatikbezogene Studiengänge zu belegen. Diesem Umstand muss in den universitären Kursen entgegengewirkt werden, um ein einheitliches Bildungsziel zu erreichen. Für einige Studierende bedeutet dies oft eine Lehrbelastung in einem ohnehin sehr zeitintensiven Studium, was nicht selten zum Studienabbruch führt. Ein anderes Problem ist die fehlende Transparenz bezüglich der Gegenstände des Informatikstudiums: einige angehende Studierende kommen mit einem von der Realität abweichenden Bild der Informatik zur Universität, andere entscheiden sich u. U. deshalb gegen ein Informatikstudium, da ihnen nicht bewusst ist, dass das Studium für sie interessant sein könnte. In diesem Artikel soll ein Lösungsvorschlag anhand eines Kompetenzrahmenmodells vorgestellt werden, mit dessen Hilfe eine Verbesserung der Hochschulsituation erreicht werden kann.
Was Bürger bem(a)erken
(2013)
Eingebettet in die aktuelle Open-Government-Debatte gewinnen E-Bürgerdienste weiter an Bedeutung. Zu den Vorreitern internetbasierter Bürgerdienste wird der Brandenburger Bürgerservice Maerker gezählt, da dieser eine einfache Möglichkeit der Kommunikation zwischen Bürger und Verwaltung über Infrastrukturprobleme in der Gemeinde bietet. Auf der Grundlage von Experteninterviews und einer Umfrage unter den teilnehmenden Kommunen evaluieren die Autoren die Einführung und Umsetzung des Maerker Brandenburgs. Im Ergebnis zeigen sich neben einer großen Breite an Akzeptanz und Zustimmung unter den beteiligten Akteuren auch unausgeschöpfte Potenziale zur Verbesserung der Prozesse innerhalb der Verwaltung. Dieser Artikel stellt die Ergebnisse der Evaluation des Maerkers dar und gibt einen Ausblick auf weitere Entwicklungspotenziale.
This study presents the theory, applicability, and merits of the new THERIAK_D add-on for the open source Theriak/Domino software package. The add-on works as an interface between Theriak and user-generated scripts, providing the opportunity to process phase equilibrium computation parameters in a programming environment (e. g., C or MATLABV (R)). THERIAK_D supports a wide range of features such as calculating the solid rock density or testing the stability of mineral phases along any pressure-temperature (P-T) path and P-T grid. To demonstrate applicability, an example is given in which the solid rock density of a 2-D-temperature-pressure field is calculated, portraying a simplified subduction zone. Consequently, the add-on effectively combines thermodynamics and geodynamic modeling. The carefully documented examples could be easily adapted for a broad range of applications. THERIAK_D is free, and the program, user manual, and source codes may be downloaded from http://www.min.unikiel.de/similar to ed/theriakd/.
Background: Short lived, iteroparous animals in seasonal environments experience variable social and environmental conditions over their lifetime. Animals can be divided into those with a "young-of-the-year" life history (YY, reproducing and dying in the summer of birth) and an "overwinter" life history (OW, overwintering in a subadult state before reproducing next spring).
We investigated how behavioural patterns across the population were affected by season and sex, and whether variation in behaviour reflects the variation in life history patterns of each season. Applications of pace-of-life (POL) theory would suggest that long-lived OW animals are shyer in order to increase survival, and YY are bolder in order to increase reproduction. Therefore, we expected that in winter and spring samples, when only OW can be sampled, the animals should be shyer than in summer and autumn, when both OW and YY animals can be sampled. We studied common vole (Microtus arvalis) populations, which express typical, intra-annual density fluctuation. We captured a total of 492 voles at different months over 3 years and examined boldness and activity level with two standardised behavioural experiments.
Results: Behavioural variables of the two tests were correlated with each other. Boldness, measured as short latencies in both tests, was extremely high in spring compared to other seasons. Activity level was highest in spring and summer, and higher in males than in females.
Conclusion: Being bold in laboratory tests may translate into higher risk-taking in nature by being more mobile while seeking out partners or valuable territories. Possible explanations include asset-protection, with OW animals being rather old with low residual reproductive value in spring. Therefore, OW may take higher risks during this season. Offspring born in spring encounter a lower population density and may have higher reproductive value than offspring of later cohorts. A constant connection between life history and animal personality, as suggested by the POL theory, however, was not found. Nevertheless, correlations of traits suggest the existence of animal personalities. In conclusion, complex patterns of population dynamics, seasonal variation in life histories, and variability of behaviour due to asset-protection may cause complex seasonal behavioural dynamics in a population.
Shrews have very high metabolic rates and are often unintentionally starved in rodent live-traps during capture mark recapture (CMR) studies. Here, we suggest a shrew exit as a modification to rodent traps. To test whether this modification is (1) saving shrews and (2) not jeopardizing results of rodent captures, we compared captures in Ugglan traps with and without shrew exits, studying bank voles (Myodes glareolus) in a spruce forest in central Finland. Numbers of captured bank voles and body size of smallest juvenile bank voles were not affected by the shrew exit, while the number of captured common shrews (Sorex araneus) was reduced from 31 to 0 individuals per 100 trap nights. However, rare larger shrew species (> 8 g body weight) could not escape through the exit. A shrew exit can, therefore, save smaller shrew species in standard live-trapping of vole-sized rodents without affecting CMR data of the rodent.
La contribution ci-dessous essaie d’expliciter quelques pistes de réflexion présentées lors de la conférence plénière sur les certifications en langue du 34e congrès de l’APLIUT à Strasbourg. Il s’agira donc de s’attarder sur les considérations du Conseil d’administration de l’APLIUT (CA d’APLIUT : 2007). La 1ère partie présentera de manière succincte des exemples de mise en situation professionnelle des étudiants dans les cours de langues étrangères en IUT. L’application de cette méthode demande de développer des compétences plus complexes que celles développées dans un cours se limitant à des sujets du vécu quotidien. Il conviendra ensuite de se demander dans quelle mesure les effets souhaités de cette approche font l’objet des épreuves de certification recommandées par les Programmes Pédagogiques Nationaux (PPN) des DUT. En raison de l’incohérence entre les cours et les épreuves de certification, la question de la certification a l’air d’être sans issue. Du fait qu’à ce jour la recherche d’une certification validant l’enseignement dans les IUT n’a toujours pas abouti au résultat escompté, il faudrait peut-être envisager de créer une attestation propre destinée aux IUT. L’atteinte de cet objectif passe par l’aboutissement d’importants travaux préliminaires et également par la valorisation d’une certification grâce à un système d’assurance qualité, voir la 3e partie.
In most cases tendency to synchrony in networks of oscillatory units increases with the coupling strength. Using the popular Hindmarsh-Rose neuronal model, we demonstrate that even for identical neurons and simple coupling the dynamics can be more complicated. Our numerical analysis for globally coupled systems and oscillator lattices reveals a new scenario of synchrony breaking with the increase of coupling, resulting in a quasiperiodic, modulated synchronous state.
In many biological and environmental applications spatially resolved sensing of molecular oxygen is desirable. A powerful tool for distributed measurements is optical time domain reflectometry (OTDR) which is often used in the field of telecommunications. We combine this technique with a novel optical oxygen sensor dye, triangular-[4] phenylene (TP), immobilized in a polymer matrix. The TP luminescence decay time is 86 ns. The short decay time of the sensor dye is suitable to achieve a spatial resolution of some meters. In this paper we present the development and characterization of a reflectometer in the UV range of the electromagnetic spectrum as well as optical oxygen sensing with different fiber arrangements.
The hypothesis is considered that the present, local Galactic cosmic-ray spectrum is, due to source intermittency, softer than average over time and over the Galaxy. Measurements of muogenic nuclides underground could provide an independent measurement of the time-averaged spectrum. Source intermittency could also account for the surprising low anisotropy reported by the IceCube Collaboration. Predictions for Galactic emission of ultrahigh-energy (UHE) quanta, such as UHE gamma rays and neutrinos, might be higher or lower than previously estimated.
We study the isoperimetric structure of asymptotically flat Riemannian 3-manifolds (M, g) that are C-0-asymptotic to Schwarzschild of mass m > 0. Refining an argument due to H. Bray, we obtain an effective volume comparison theorem in Schwarzschild. We use it to show that isoperimetric regions exist in (M, g) for all sufficiently large volumes, and that they are close to centered coordinate spheres. This implies that the volume-preserving stable constant mean curvature spheres constructed by G. Huisken and S.-T. Yau as well as R. Ye as perturbations of large centered coordinate spheres minimize area among all competing surfaces that enclose the same volume. This confirms a conjecture of H. Bray. Our results are consistent with the uniqueness results for volume-preserving stable constant mean curvature surfaces in initial data sets obtained by G. Huisken and S.-T. Yau and strengthened by J. Qing and G. Tian. The additional hypotheses that the surfaces be spherical and far out in the asymptotic region in their results are not necessary in our work.
We studied bacterial associations with the green alga Desmodesmus armatus and the diatom Stephanodiscus minutulus under changing environmental conditions and bacterial source communities, to evaluate whether bacteriaalgae associations are species-specific or more generalized and determined by external factors. Axenic and xenic algae were incubated in situ with and without allelopathically active macrophytes, and in the laboratory with sterile and nonsterile lake water and an allelochemical, tannic acid (TA). Bacterial community composition (BCC) of algae-associated bacteria was analyzed by denaturing gradient gel electrophoresis (DGGE), nonmetric multidimensional scaling, cluster analyses, and sequencing of DGGE bands. BCC of xenic algal cultures of both species were not significantly affected by changes in their environment or bacterial source community, except in the case of TA additions. Species-specific interactions therefore appear to overrule the effects of environmental conditions and source communities. The BCC of xenic and axenic D.armatus cultures subjected to in situ bacterial colonization, however, had lower similarities (ca.55%), indicating that bacterial precolonization is a strong factor for bacteriaalgae associations irrespective of environmental conditions and source community. Our findings emphasize the ecological importance of species-specific bacteriaalgae associations with important repercussions for other processes, such as the remineralization of nutrients, and organic matter dynamics.
Recent evidences indicating that cellular kinase signaling cascades are triggered by oligomers of N-acetylglucosamine (ChOS) and that condrocytes of human osteoarthritic cartilage secrete the inflammation associated chitolectin YKL-40, prompted us to study the binding affinity of partially acetylated ChOS to YKL-40 and their effect on primary chondrocytes in culture. Extensive chitinase digestion and filtration of partially deacetylated chitin yielded a mixture of ChOS (Oligomin(TM)) and further ultrafiltration produced T-ChOS(TM), with substantially smaller fraction of the smallest sugars. YKL-40 binding affinity was determined for the different sized homologues, revealing micromolar affinities of the larger homologues to YKL-40. The response of osteoarthritic chondrocytes to Oligomin(TM) and T-ChOS(TM) was determined, revealing 2- to 3-fold increases in cell number. About 500 mu g/ml was needed for Oligomin(TM) and around five times lower concentration for T-ChOS(TM), higher concentrations abolished this effect for both products. Addition of chitotriose inhibited cellular responses mediated by larger oligosaccharides. These results, and the fact that the partially acetylated T-ChOS(TM) homologues should resist hydrolysis, point towards a new therapeutic concept for treating inflammatory joint diseases.
Anglizismen im Deutschen
(2013)
Der vorliegende Artikel befasst sich mit Adventure-based Learning, einer digitalen, spielbasierten Lernmethode. Das Ziel derartiger Anwendungen ist es, Motivation und Begeisterung der Lernenden zu stimulieren und dadurch Lernprozesse zu unterstützen. Die Frage, inwiefern Adventure-based Learning tatsächlich lernförderliche Mehrwerte induziert, wird anhand einer Fallstudie im Kontext betrieblicher Weiterbildung untersucht. Hierzu wird ein Experiment mit 40 Probanden durchgeführt, in der eine Adventure-based Learning-Anwendung mit einer interaktiven Powerpoint-Präsentation verglichen wird. Die Ergebnisse der Untersuchung deuten darauf hin, dass viele Lernende sich Lernprogramme wünschen, die weniger textlastig sind und mit Adventure-based Learning eine vergleichbare Behaltensleistung erreicht wird.
We comprehensively analyze the emergence of anomalous statistics in the context of the random relaxation ( RARE) model [Eliazar and Metzler, J. Chem. Phys. 137, 234106 ( 2012)], a recently introduced versatile model of random relaxations in random environments. The RARE model considers excitations scattered randomly across a metric space around a reaction center. The excitations react randomly with the center, the reaction rates depending on the excitations' distances from this center. Relaxation occurs upon the first reaction between an excitation and the center. Addressing both the relaxation time and the relaxation range, we explore when these random variables display anomalous statistics, namely, heavy tails at zero and at infinity that manifest, respectively, exceptionally high occurrence probabilities of very small and very large outliers. A cohesive set of closed-form analytic results is established, determining precisely when such anomalous statistics emerge.
Event-related potentials (ERPs) to single visual stimuli were recorded in 7-month-old infants. In a three-stimulus oddball paradigm, infants watched one frequently occurring standard stimulus (either an animal or a furniture item) and two infrequently occurring oddball stimuli, presenting one exemplar from the same and one from the different super-ordinate category as compared to the standard stimulus. Additionally, visual attributes of the stimuli were controlled to investigate whether infants focus on category membership or on perceptual similarity when processing the stimuli. Infant ERPs indicated encoding of the standard stimulus and discriminating it from the two oddball stimuli by larger Nc peak amplitude and late-slow-wave activity for the infrequent stimuli. Moreover, larger Nc latency and positive-slow-wave activity indicated increased processing for the different-category as compared to the same-category oddball. Thus, 7-month-olds seem to encode single stimuli not only by surface perceptual features, but they also regard information of category membership, leading to facilitated processing of the oddball that belongs to the same domain as the standard stimulus.
Rational action understanding requires that infants evaluate the efficiency of a movement in achieving a goal with respect to situational constraints. In contrast, recent accounts have highlighted the impact of perceptual characteristics of the demonstrated movement or constraints to explain infants' behavior in so-called rational imitation tasks. The current study employed eye tracking to investigate how 13- to 15-month-old infants distribute their visual attention to different aspects of an action demonstration. In three tasks (touchlight, house, and obstacle), infants watched videos in which a model performed an unusual action while she was or was not restricted by situational constraints. Infants' overall looking to the demonstration as well as looking to four segments of the video (initial segment, constraint demonstration, action performance, and final segment) and to specific areas (constraint area of interest [AOI] and action AOI) was analyzed. Overall, infants looked longer at the demonstration in the constraint condition compared with the no-constraint condition. The condition differences occurred in the two video segments where the constraint or action was displayed and were especially profound for the constraint AOI. These findings indicate that infants processed the situational constraints. However, the pattern of condition differences varied slightly in the three tasks. In sum, the data imply that infants process perceptual characteristics of the movement or constraints and that low-level perceptual processes interact with higher level cognitive processes in infants' action perception.
In diesem Beitrag berichten wir über die Erfahrungen einer umgestalteten Lehre im Bereich Informatik und Gesellschft (IuG). Die Gründe für die Umge staltung und die Konzeption werden skizziert. Die Erfahrungen haben wir zu Thesen verdichtet: 1. Informatik und Gesellschaft sollte eine Pflichtveranstaltung im Bachelor-Studium sein, in der Studierende einen Überblick erhalten, welche gesellschaftlichen Rahmenbedingungen für sie relevant sind und wie man diese in die Praxis mit einbeziehen kann. 2. Historische Inhalte der Informatik sollen hier aufgearbeitet werden, indem man aktuelle Entwicklungen im Kontext ihrer Genese betrachtet.
We explore the interaction between oculomotor control and language comprehension on the sentence level using two well-tested computational accounts of parsing difficulty. Previous work (Boston, Hale, Vasishth, & Kliegl, 2011) has shown that surprisal (Hale, 2001; Levy, 2008) and cue-based memory retrieval (Lewis & Vasishth, 2005) are significant and complementary predictors of reading time in an eyetracking corpus. It remains an open question how the sentence processor interacts with oculomotor control. Using a simple linking hypothesis proposed in Reichle, Warren, and McConnell (2009), we integrated both measures with the eye movement model EMMA (Salvucci, 2001) inside the cognitive architecture ACT-R (Anderson et al., 2004). We built a reading model that could initiate short Time Out regressions (Mitchell, Shen, Green, & Hodgson, 2008) that compensate for slow postlexical processing. This simple interaction enabled the model to predict the re-reading of words based on parsing difficulty. The model was evaluated in different configurations on the prediction of frequency effects on the Potsdam Sentence Corpus. The extension of EMMA with postlexical processing improved its predictions and reproduced re-reading rates and durations with a reasonable fit to the data. This demonstration, based on simple and independently motivated assumptions, serves as a foundational step toward a precise investigation of the interaction between high-level language processing and eye movement control.
Small and medium-sized enterprises (SME) contribute to innovation and economic growth, despite their resource shortages and lack of professional intellectual property (IP) management practices. Drawing on social practice theory and combining insights from recent scholarship on IP strategies and its management, this paper examines the cases of three pharmaceutical SME providing insights into how they appropriate returns on research and development (R&D) investments. It discusses their IP strategies and management practices, examining how the IP management practices are embedded in the firm's organisational structure. Moreover, this paper develops recommendations for SME regarding the professionalisation of their IP management practices.
1. Die Produzenten eines Schulbuchs 2. Erwartungen an Schulbücher 3. Schulbuchzulassung 4. Einschätzung der Lehrerinnen und Lehrer 5. Verlegerische Herausforderungen durch den Wandel des Schulbuchs 6. Herausforderungen des Informationszeitalters 7. Das Schulbuch für den Geographieunterricht - Ein "heimlicher" Lehrplan?
Irradiating a ferromagnet with a femtosecond laser pulse is known to induce an ultrafast demagnetization within a few hundred femtoseconds. Here we demonstrate that direct laser irradiation is in fact not essential for ultrafast demagnetization, and that electron cascades caused by hot electron currents accomplish it very efficiently. We optically excite a Au/Ni layered structure in which the 30 nm Au capping layer absorbs the incident laser pump pulse and subsequently use the X-ray magnetic circular dichroism technique to probe the femtosecond demagnetization of the adjacent 15 nm Ni layer. A demagnetization effect corresponding to the scenario in which the laser directly excites the Ni film is observed, but with a slight temporal delay. We explain this unexpected observation by means of the demagnetizing effect of a superdiffusive current of non-equilibrium, non-spin-polarized electrons generated in the Au layer.
Background and objectives Trials with the antioxidant vitamin E have failed to show benefit in the general population. Considering the different causes of death in ESRD, this study investigated the association between plasma concentrations of alpha-tocopherol and specific clinical outcomes in diabetic hemodialysis patients.
Design, settings, participants, & measurements In 1046 diabetic hemodialysis patients (participants of the German Diabetes and Dialysis Study), alpha-tocopherol was measured in plasma by reversed-phase HPLC. By Cox regression analyses, hazard ratios were determined for prespecified end points according to baseline plasma alpha-tocopherol levels: sudden death (n=134), myocardial infarction (n=172), stroke (n=89), combined cardiovascular events (n=398), fatal infection (n=107), and all-cause mortality (n=508).
Results Patients had a mean age of 66 8 years, and mean plasma alpha-tocopherol level was 22.8+/-9.6 mu mol/L. Levels of alpha-tocopherol were highly correlated to triglycerides (r=0.63, P<0.001). Patients in the lowest alpha-tocopherol quartile had (in unadjusted analyses) a 79% higher risk of stroke and a 31% higher risk of all-cause mortality compared with patients in the highest quartile. The associations were attenuated after adjustment for confounders (hazard ratio(stroke)=1.56, 95% confidence interval=0.75-3.25; hazard ratio(mortality)=1.22, 95% confidence interval=0.89-1.69, respectively). There was no association between alpha-tocopherol and myocardial infarction, sudden death, or infectious death.
Conclusions Plasma alpha-tocopherol concentrations were not independently associated with cardiovascular outcomes, infectious deaths, or all-cause mortality in diabetic hemodialysis patients. The lack of association can partly be explained by a confounding influence of malnutrition, which should be considered in the planning of trials to reduce cardiovascular risk in dialysis patients.
Fußball als Text : Überlegungen zu den Weltmeisterschaften, Costa Rica und den Kulturwissenschaften
(2013)
Coca Cola und "Coolitude"
(2013)
Miedo y catástrofe : miedo ante la catástrofe ; sobre la economía del miedo de cara a la muerte
(2013)
Miedo y catástrofe = Miedo ante la catástrofe : sobre la economía del miedo de cara a la muerte
(2013)
"Mobile mappings" y las literaturas sin residencia fija : Perspectivas de una poética del movimiento
(2013)
Migration und Konvivenz
(2013)
Pensamiento nómada
(2013)
fundamental challenge for product-lifecycle management in collaborative value networks is to utilize the vast amount of product information available from heterogeneous sources in order to improve business analytics, decision support, and processes. This becomes even more challenging if those sources are distributed across multiple organizations. Federations of semantic information services, combining service-orientation and semantic technologies, provide a promising solution for this problem. However, without proper measures to establish information security, companies will be reluctant to join an information federation, which could lead to serious adoption barriers.
Following the design science paradigm, this paper presents general objectives and a process for designing a secure federation of semantic information services. Furthermore, new as well as established security measures are discussed. Here, our contributions include an access-control enforcement system for semantic information services and a process for modeling access-control policies across organizations. In addition, a comprehensive security architecture is presented. An implementation of the architecture in the context of an application scenario and several performance experiments demonstrate the practical viability of our approach.
beta(2)-microglobulin (beta(2)m) is known to be the major component of fibrillar deposits in the joints of patients suffering from dialysis-related amyloidosis. We have developed a simplified procedure to convert monomeric recombinant beta(2)m into amyloid fibrils at physiological pH by a combination of stirring and heating, enabling us to follow conformational changes associated with the assembly by infrared spectroscopy and electron microscopy. Our studies reveal that fibrillogenesis begins with the formation of relatively large aggregates, with secondary structure not significantly altered by the stirring-induced association. In contrast, the conversion of the amorphous aggregates into amyloid fibrils is associated with a profound re-organization at the level of the secondary and tertiary structures, leading to non-native like parallel arrangements of the beta-strands in the fully formed amyloid structure of beta(2)m. This study highlights the power of an approach to investigate the formation of beta(2)m fibrils by a combination of biophysical techniques including IR spectroscopy.
Reliable hydrological monitoring is the basis for sound water management in drained wetlands. Since statistical methods cannot be employed for unobserved or sparsely monitored areas, the primary design (first set-up) may be arbitrary in most instances. The objective of this paper is therefore to provide a guideline for designing the initial hydrological monitoring network. A scheme is developed that handles different parts of monitoring and hydrometry in wetlands, focusing on the positioning of surface water and groundwater gauges. For placement of the former, control units are used which correspond to areas whose water levels can be regulated separately. The latter are arranged depending on hydrological response units, defined by combinations of soil type and land use, and the chosen surface water monitoring sites. A practical application of the approach is shown for an investigation area in the Spreewald region in north-east Germany. The presented scheme leaves a certain degree of freedom to its user, allowing the inclusion of expert knowledge or special concerns. Based on easily obtainable data, the developed hydrological network serves as a first step in the iterative procedure of monitoring network optimisation. Copyright (c) 2013 John Wiley & Sons, Ltd.
The German Banking System
(2013)
Ca2+ and cAMP signalling pathways interact in a complex manner at multiple sites. This crosstalk fine-tunes the spatiotemporal patterns of Ca2+ and cAMP signals. In salivary glands of the blowfly Calliphora vicina fluid secretion is stimulated by serotonin (5-hydroxytryptamine, 5-HT) via activation of two different 5-HT receptors coupled to the InsP(3)/Ca2+ (Cv5-HT2 alpha) or the cAMP pathway (Cv5-HT7), respectively. We have shown recently in permeabilized gland cells that cAMP sensitizes InsP(3)-induced Ca2+ release to InsP(3). Here we study the effects of the CAMP signalling pathway on 5-HT-induced oscillations in transepithelial potential (TEP) and in intracellular [Ca2+]. We show: (1) Blocking the activation of the cAMP pathway by cinanserin suppresses the generation of TEP and Ca2+ oscillations, (2) application of 8-CPT-cAMP in the presence of cinanserin restores 5-HT-induced TEP and Ca2+ oscillations, (3) 8-CPT-cAMP sensitizes the InsP(3)/Ca2+ signalling pathway to 5-HT and the Cv5-HT2 alpha, receptor agonist 5-MeOT, (4) 8-CPT-cAMP induces Ca2+ oscillations in cells loaded with subthreshold concentrations of InsP(3), (5) inhibition of protein kinase A by H-89 abolishes 5-HT-induced TEP and Ca2+ spiking and mimics the effect of cinanserin. These results suggest that activation of the cyclic AMP pathway promotes the generation of 5-HT-induced Ca2+ oscillations in blowfly salivary glands.