TY - JOUR A1 - Eizner, E. A1 - Horovitz, Baruch A1 - Henkel, Carsten T1 - Van der waals-casimir-polder interaction of an atom with a composite surface JF - The European physical journal : D, Atomic, molecular, optical and plasma physics N2 - We study the dispersion interaction of the van der Waals and Casimir-Polder (vdW-CP) type between a neutral atom and the surface of a conductor by allowing for nonlocal electrodynamics, i.e. electron diffusion. We consider two models: (i) bulk diffusion, and (ii) diffusion in a surface charge layer. In both cases, we find that the transition to a semiconductor as a function of the conductivity is continuous, unlike the case of a local model. The relevant parameter is the electric screening length and depends on the carrier diffusion constant. We find that for distances comparable to the screening length, vdW-CP data can distinguish between bulk and surface diffusion, hence it can be a sensitive probe for surface states. Y1 - 2012 U6 - https://doi.org/10.1140/epjd/e2012-30294-x SN - 1434-6060 VL - 66 IS - 12 PB - Springer CY - New York ER - TY - JOUR A1 - Bödecker, Geesche A1 - Henkel, Carsten T1 - Validity of the quantum regression theorem for resonance fluorescence in a photonic crystal JF - Annalen der Physik N2 - Correlation functions of a driven two-level system embedded in a photonic crystal are analyzed. The spectral density of the photonic bands near a gap makes this system non-Markovian. The equations of motion for two-time correlations are derived by two different methods, the quantum regression theorem and the fluctuation dissipation theorem, and found to be the same. KW - Resonance fluorescence KW - fluctuation dissipation theorem KW - quantum regression theorem KW - non-Markovian dynamics KW - open quantum system KW - photonic bandgap Y1 - 2012 U6 - https://doi.org/10.1002/andp.201200135 SN - 0003-3804 VL - 524 IS - 12 SP - 805 EP - 813 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Müller, Juliane A1 - Mayer, Frank T1 - Validity of isokinetic trunk measurements with respect to healthy adults, athletes and low back pain patients JF - Isokinetics and exercise science : official journal of the European Isokinetic Society N2 - Background: Isokinetic measurements are widely used to assess strength capacity in a clinical or research context. Nevertheless, the validity of isokinetic measures for identifying strength deficits and the evaluation of therapeutic process regarding different pathologies is yet to be established. Therefore, the purpose of this review is to evaluate the validity of isokinetic measures in a specific case: that of muscular capacity in low back pain (LBP). Methods: A literature search (PubMed; ISI Web of Knowledge; The Cochrane Library) covering the last 10 years was performed. Relevant papers regarding isokinetic trunk strength measures in healthy and patients with low back pain (PLBP) were searched. Peak torque values [Nm] and peak torque normalized to body weight [Nm/kg BW] were extracted for healthy and PLBP. Ranked mean values across studies were calculated for the concentric peak torque at 60 degrees/s as well as the flexion/extension (F/E) ratio. Results: 34 publications (31 flexion/extension; 3 rotation) were suitable for reporting detailed isokinetic strength measures in healthy or LBP (untrained adults, adolescents, athletes). Adolescents and athletes were different compared to normal adults in terms of absolute trunk strength values and the F/E ratio. Furthermore, isokinetic measures evaluating therapeutic process and isokinetic rehabilitation training were infrequent in literature (8 studies). Conclusion: Isokinetic measurements are valid for measuring trunk flexion/extension strength and F/E ratio in athletes, adolescents and (untrained) adults with/without LBP. The validity of trunk rotation is questionable due to a very small number of publications whereas no reliable source regarding lateral flexion could be traced. Therefore, isokinetic dynamometry may be utilized for identifying trunk strength deficits in healthy adults and PLBP. KW - Isokinetic KW - validity KW - low back pain KW - peak torque KW - trunk Y1 - 2012 U6 - https://doi.org/10.3233/IES-2012-00482 SN - 0959-3020 VL - 20 IS - 4 SP - 255 EP - 266 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Rohner, Fabian A1 - Garrett, Greg S. A1 - Laillou, Arnaud A1 - Frey, Simone K. A1 - Mothes, Ralf A1 - Schweigert, Florian J. A1 - Locatelli-Rossi, Lorenzo T1 - Validation of a user-friendly and rapid method for quantifying iodine content of salt JF - Food and nutrition bulletin N2 - Background. Despite considerable progress made in the past decade through salt iodization programs, over 2 billion people worldwide still have inadequate iodine intake, with devastating consequences for brain development and intellectual capacity. To optimize these programs with regard to salt iodine content, careful monitoring of salt iodine content is essential, but few methods are available to quantitatively measure iodine concentration in a simple, fast, and safe way. Objective. We have validated a newly developed device that quantitatively measures the content of potassium iodate in salt in a simple, safe, and rapid way. Methods. The linearity, determination and detection limit, and inter- and intra-assay variability of this colorimetric method were assessed and the method was compared with iodometric titration, using salt samples from several countries. Results. Linearity of analysis ranged from 5 to 75 mg/kg iodine, with I mg/kg being the determination limit; the intra- and interassay imprecision was 0.9%, 0.5%, and 0.7% and 1.5%, 1.7%, and 2.5% for salt samples with iodine contents of 17, 30, and 55 mg/kg, respectively; the interoperator imprecision for the same samples was 1.2%, 4.9%, and 4.7%, respectively. Comparison with the iodometric method showed high agreement between the methods (R-2 = 0.978; limits of agreement, -10.5 to 10.0 mg/kg). Conclusions. The device offers a field- and user-friendly solution to quantifying potassium iodate salt content reliably. For countries that use potassium iodide in salt iodization programs, further validation is required. KW - Iodization KW - iodine KW - monitoring KW - potassium iodate KW - quality control KW - rapid test kit KW - regulatory monitoring KW - salt Y1 - 2012 SN - 0379-5721 VL - 33 IS - 4 SP - S330 EP - S335 PB - International Nutrition Foundation CY - Boston ER - TY - JOUR A1 - Raila, Jens A1 - Enjalbert, Francis A1 - Mothes, Ralf A1 - Hurtienne, Andrea A1 - Schweigert, Florian J. T1 - Validation of a new point-of-care assay for determination of ss-carotene concentration in bovine whole blood and plasma JF - Veterinary clinical pathology N2 - Background: beta-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. beta-Carotene concentrations in plasma are used to optimize beta-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure beta-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC). Objective: The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring beta-carotene in whole blood and plasma. Methods: beta-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene). Results: Concentrations of beta-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean +/- SD; n = 166): HPLC-plasma 4.23 +/- 2.35 mg/L; POC-plasma 4.49 +/- 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 +/- 2.12 mg/L; POC-whole blood 3.67 +/- 2.29 mg/L. Conclusions: Concentrations of beta-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding beta-carotene deficiency facilitates rapid and appropriate optimization of beta-carotene supplementation in feed. KW - Biomarker KW - HPLC KW - method comparison KW - nutritional supplements KW - vitamin A Y1 - 2012 U6 - https://doi.org/10.1111/j.1939-165X.2012.00400.x SN - 0275-6382 VL - 41 IS - 1 SP - 119 EP - 122 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Funk, Roger A1 - Li, Yong A1 - Hoffmann, Carsten A1 - Reiche, Matthias A1 - Zhang, Zhuodong A1 - Li, Junjie A1 - Sommer, Michael T1 - Using Cs-137 to estimate wind erosion and dust deposition on grassland in Inner Mongolia-selection of a reference site and description of the temporal variability JF - Plant and soil N2 - The aims of this study were to identify areas of wind erosion and dust deposition and to quantify the effects of different grazing intensities on soil redistribution rates in grasslands based on the Cs-137 technique. Because the method uses a reference inventory as threshold for erosion or deposition, the classification of any other site as source or sink for dust depends on the accurate selection of this reference site. Measurements of Cs-137 inventories and depth distributions were carried out at pasture sites with predominant species of Stipa grandis and Leymus chinensis which are grazed with different intensities. Additional measurements were made at arable land, plant-covered sand dunes and alluvial plains. Wind-induced soil erosion and dust deposition rates were calculated from Cs-137 inventories by means of the "Profile-Distribution" and the "Mass Balance II" models. The selection of the reference site was based on fluid dynamical and process-determining parameters. The chosen site should meet the following four conditions: (i) located at a summit position with obviously low deposition rates, (ii) sufficient vegetation cover to prevent wind erosion, (iii) plane to exclude water erosion and (iv) in the wind/dust shadow of a higher elevation. The measured reference inventory of Cs-137 was 1967(+/- 102) Bqm(-2) located at a summit position of moderately grazed Leymus chinensis steppe. The Cs-137 inventories at other sites ranged from 1330 Bqm(-2) at heavily grazed sites to 5119 Bqm(-2) at river deposits, representing annual average soil losses of up to 130 tkm(-2) and deposits of up to 540 tkm(-2), respectively. The calculated annual averages of dust depositions at ungrazed Leymus chinensis sites were related to the dust storm frequencies of the last 50 years resulting in a description of the temporal variability of annual dust depositions from about 154 tkm(-2) in the 1960s to 26 tkm(-2) at recent times. Based on this quantification already 80% of the total dust depositions can be related to the 20 years between the 1960s and the end of the 1970s and only 20% to the time between 1980 and 2001. Cs-137 technique is a promising method to assess the effect of grazing intensity and land use types on the spatial variability of wind-induced soil and dust redistribution processes in semi-arid grasslands. However, considerable efforts are needed to identify a reliable reference site, because erosion and deposition induced by wind may occur at the same places. The combination of the dust deposition rates derived from Cs-137 profile data with the dust storm frequencies is helpful for a better reconstruction of the temporal variability of dust deposition and wind erosion in this region. The calculated recent deposition rates of about 20 tkm(-2) are in good agreement with data of other authors. KW - Cs-137 KW - Grassland KW - Wind erosion KW - Dust deposition KW - Reference site Y1 - 2012 U6 - https://doi.org/10.1007/s11104-011-0964-y SN - 0032-079X VL - 351 IS - 1-2 SP - 293 EP - 307 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Hartwich, Melanie A1 - Straile, Dietmar A1 - Gaedke, Ursula A1 - Wacker, Alexander T1 - Use of ciliate and phytoplankton taxonomic composition for the estimation of eicosapentaenoic acid concentration in lakes JF - Freshwater biology N2 - 1. The polyunsaturated fatty acid eicosapentaenoic acid (EPA) plays an important role in aquatic food webs, in particular at the primary producerconsumer interface where keystone species such as daphnids may be constrained by its dietary availability. Such constraints and their seasonal and interannual changes may be detected by continuous measurements of EPA concentrations. However, such EPA measurements became common only during the last two decades, whereas long-term data sets on plankton biomass are available for many well-studied lakes. Here, we test whether it is possible to estimate EPA concentrations from abiotic variables (light and temperature) and the biomass of prey organisms (e.g. ciliates, diatoms and cryptophytes) that potentially provide EPA for consumers. 2. We used multiple linear regression to relate size- and taxonomically resolved plankton biomass data and measurements of temperature and light intensity to directly measured EPA concentrations in Lake Constance during a whole year. First, we tested the predictability of EPA concentrations from the biomass of EPA-rich organisms (diatoms, cryptophytes and ciliates). Secondly, we included the variables mean temperature and mean light intensity over the sampling depth (020 m) and depth (08 and 820 m) as factors in our model to check for large-scale seasonal- and depth-dependent effects on EPA concentrations. In a third step, we included the deviations of light and temperature from mean values in our model to allow for their potential influence on the biochemical composition of plankton organisms. We used the Akaike Information Criterion to determine the best models. 3. All approaches supported our proposition that the biomasses of specific plankton groups are variables from which seston EPA concentrations can be derived. The importance of ciliates as an EPA source in the seston was emphasised by their high weight in our models, although ciliates are neglected in most studies that link fatty acids to seston taxonomic composition. The large-scale seasonal variability of light intensity and its interaction with diatom biomass were significant predictors of EPA concentrations. The deviation of temperature from mean values, accounting for a depth-dependent effect on EPA concentrations, and its interaction with ciliate biomass were also variables with high predictive power. 4. The best models from the first and second approaches were validated with measurements of EPA concentrations from another year (1997). The estimation with the best model including only biomass explained 80%, and the best model from the second approach including mean temperature and depth explained 87% of the variability in EPA concentrations in 1997. 5. We show that it is possible to predict EPA concentrations reliably from plankton biomass, while the inclusion of abiotic factors led to results that were only partly consistent with expectations from laboratory studies. Our approach of including biotic predictors should be transferable to other systems and allow checking for biochemical constraints on primary consumers. KW - ciliates KW - diatoms KW - eicosapentaenoic acid KW - light KW - temperature Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-2427.2012.02799.x SN - 0046-5070 VL - 57 IS - 7 SP - 1385 EP - 1398 PB - Wiley-Blackwell CY - Hoboken ER - TY - CHAP A1 - Neumann-Schaal, M. A1 - Messerschmidt, Katrin A1 - Grenz, N. A1 - Micheel, Burkhard A1 - Heilmann, K. T1 - Use of antibody gene library for the isolation of specific single chain antibodies by ampicillin-antigen conjugates T2 - Immunology : an official journal of the British Society for Immunology Y1 - 2012 SN - 0019-2805 VL - 137 IS - 3 SP - 661 EP - 661 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Bang, Guri A1 - Hovi, Jon A1 - Sprinz, Detlef F. T1 - US presidents and the failure to ratify multilateral environmental agreements JF - Climate policy N2 - Whereas the US President signed the Kyoto Protocol, the failure of the US Congress to ratify it seriously hampered subsequent international climate cooperation. This recent US trend, of signing environmental treaties but failing to ratify them, could thwart attempts to come to a future climate agreement. Two complementary explanations of this trend are proposed. First, the political system of the US has distinct institutional features that make it difficult for presidents to predict whether the Senate will give its advice and consent to multilateral environmental agreements (MEAs) and whether Congress will pass the required enabling legislation. Second, elected for a fixed term, US presidents might benefit politically from supporting MEAs even when knowing that legislative support is not forthcoming. Four policy implications are explored, concerning the scope for unilateral presidential action, the potential for bipartisan congressional support, the effectiveness of a treaty without the US, and the prospects for a deep, new climate treaty. Policy relevance Why does the failure of US ratification of multilateral environmental treaties occur? This article analyses the domestic political mechanisms involved in cases of failed US ratification. US non-participation in global environmental institutions often has serious ramifications. For example, it sharply limited Kyoto's effectiveness and seriously hampered international climate negotiations for years. Although at COP 17 in Durban the parties agreed to negotiate a new agreement by 2015, a new global climate treaty may well trigger a situation resembling the one President Clinton faced in 1997 when he signed Kyoto but never obtained support for it in the Senate. US failure to ratify could thwart future climate agreements. KW - enabling legislation KW - environmental treaties KW - Kyoto Protocol KW - political processes KW - ratification KW - United States Y1 - 2012 U6 - https://doi.org/10.1080/14693062.2012.699788 SN - 1469-3062 VL - 12 IS - 6 SP - 755 EP - 763 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Kirpichenko, Svetlana V. A1 - Shainyan, Bagrat A. A1 - Kleinpeter, Erich T1 - Unusual conformational preferences of 1,3-dimethyl-3-isopropoxy-3-silapiperidine JF - Journal of physical organic chemistry N2 - The conformational analysis of the first representative of the Si-alkoxy substituted six-membered Si,N-heterocycles, 1,3-dimethyl-3-isopropoxy-3-silapiperidine, was performed by low-temperature 1H and 13C NMR spectroscopy and DFT theoretical calculations. In contrast to the expectations from the conformational energies of methyl and alkoxy substituents, the Meaxi-PrOeq conformer was found to predominate in the conformational equilibrium in the ratio Meaxi-PrOeq : Meeqi-PrOax of ca. 2 : 1 as from the 1H and 13C NMR study. The thermodynamic parameters obtained by the complete line shape analysis showed that the main contribution to the barrier to ring inversion originates from the entropy term of the free energy of activation. KW - barrier to ring inversion KW - conformational equilibrium KW - DFT theoretical calculations KW - dynamic NMR KW - silapiperidines Y1 - 2012 U6 - https://doi.org/10.1002/poc.3028 SN - 0894-3230 VL - 25 IS - 12 SP - 1321 EP - 1327 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Keehner, Madeleine A1 - Fischer, Martin H. T1 - Unusual bodies, uncommon behaviors individual and group differences in embodied cognition in spatial tasks JF - Spatial cognition and computation N2 - This editorial introduces a set of papers on differential embodiment in spatial tasks. According to the theoretical notion of embodied cognition, our experiences of acting in the world, and the constraints of our sensory and motor systems, strongly shape our cognitive functions. In the current set of papers, the authors were asked to particularly consider idiosyncratic or differential embodied cognition in the context of spatial tasks and processes. In each contribution, differential embodiment is considered from one of two complementary perspectives: either by considering unusual individuals, who have atypical bodies or uncommon experiences of interacting with the world; or by exploring individual differences in the general population that reflect the naturally occurring variability in embodied processes. Our editorial summarizes the contributions to this special issue and discusses the insights they offer. We conclude from this collection of papers that exploring differences in the recruitment and involvement of embodied processes can be highly informative, and can add an extra dimension to our understanding of spatial cognitive functions. Taking a broader perspective, it can also shed light on important theoretical and empirical questions concerning the nature of embodied cognition per se. KW - embodied cognition KW - spatial cognition KW - individual differences KW - spatial ability KW - strategy KW - expertise KW - mental representation Y1 - 2012 U6 - https://doi.org/10.1080/13875868.2012.659303 SN - 1387-5868 VL - 12 IS - 2-3 SP - 71 EP - 82 PB - Taylor & Francis Group CY - Philadelphia ER - TY - THES A1 - Matallana-Ramírez, Lilian Paola T1 - Unraveling the ORE1 regulon in Arabidopsis thaliana : molecular and functional characterization of up- and down-stream components T1 - Aufklärung des ORE1-Regulationsnetzwerks in Arabidopsis thaliana : molekulare und funktionelle Charakterisierung von Über- und untergeordneten Komponenten N2 - Leaf senescence is an active process required for plant survival, and it is flexibly controlled, allowing plant adaptation to environmental conditions. Although senescence is largely an age-dependent process, it can be triggered by environmental signals and stresses. Leaf senescence coordinates the breakdown and turnover of many cellular components, allowing a massive remobilization and recycling of nutrients from senescing tissues to other organs (e.g., young leaves, roots, and seeds), thus enhancing the fitness of the plant. Such metabolic coordination requires a tight regulation of gene expression. One important mechanism for the regulation of gene expression is at the transcriptional level via transcription factors (TFs). The NAC TF family (NAM, ATAF, CUC) includes various members that show elevated expression during senescence, including ORE1 (ANAC092/AtNAC2) among others. ORE1 was first reported in a screen for mutants with delayed senescence (oresara1, 2, 3, and 11). It was named after the Korean word “oresara,” meaning “long-living,” and abbreviated to ORE1, 2, 3, and 11, respectively. Although the pivotal role of ORE1 in controlling leaf senescence has recently been demonstrated, the underlying molecular mechanisms and the pathways it regulates are still poorly understood. To unravel the signaling cascade through which ORE1 exerts its function, we analyzed particular features of regulatory pathways up-stream and down-stream of ORE1. We identified characteristic spatial and temporal expression patterns of ORE1 that are conserved in Arabidopsis thaliana and Nicotiana tabacum and that link ORE1 expression to senescence as well as to salt stress. We proved that ORE1 positively regulates natural and dark-induced senescence. Molecular characterization of the ORE1 promoter in silico and experimentally suggested a role of the 5’UTR in mediating ORE1 expression. ORE1 is a putative substrate of a calcium-dependent protein kinase named CKOR (unpublished data). Promising data revealed a positive regulation of putative ORE1 targets by CKOR, suggesting the phosphorylation of ORE1 as a requirement for its regulation. Additionally, as part of the ORE1 up-stream regulatory pathway, we identified the NAC TF ATAF1 which was able to transactivate the ORE1 promoter in vivo. Expression studies using chemically inducible ORE1 overexpression lines and transactivation assays employing leaf mesophyll cell protoplasts provided information on target genes whose expression was rapidly induced upon ORE1 induction. First, a set of target genes was established and referred to as early responding in the ORE1 regulatory network. The consensus binding site (BS) of ORE1 was characterized. Analysis of some putative targets revealed the presence of ORE1 BSs in their promoters and the in vitro and in vivo binding of ORE1 to their promoters. Among these putative target genes, BIFUNCTIONAL NUCLEASE I (BFN1) and VND-Interacting2 (VNI2) were further characterized. The expression of BFN1 was found to be dependent on the presence of ORE1. Our results provide convincing data which support a role for BFN1 as a direct target of ORE1. Characterization of VNI2 in age-dependent and stress-induced senescence revealed ORE1 as a key up-stream regulator since it can bind and activate VNI2 expression in vivo and in vitro. Furthermore, VNI2 was able to promote or delay senescence depending on the presence of an activation domain located in its C-terminal region. The plasticity of this gene might include alternative splicing (AS) to regulate its function in different organs and at different developmental stages, particularly during senescence. A model is proposed on the molecular mechanism governing the dual role of VNI2 during senescence. N2 - Der Alterungsprozess lebender Organismen wird seit vielen Jahren wissenschaftlich untersucht. In Pflanzen wird der Alterungsprozess Seneszenz genannt. Er ist für das Überleben der Pflanze von großer Bedeutung. Dennoch ist unser Wissen über die molekularen Mechanismen der Blattseneszenz, dessen komplexe Steuerung und die Wechselwirkungen mit Umweltsignale noch sehr limitiert. Ein wichtiges Steuerungselement besteht in der Aktivierung bestimmter Transkriptionsfaktoren (TFs) die während der Seneszenz unterschiedlich exprimiert werden. Aus der Literatur ist bekannt, dass Mitglieder der NAC TF Familie (NAM/ATAF/CUC) an der Regulation der Seneszenz bei Pflanzen beteiligt sind. ORE1 (ANAC092/AtNAC2), ein NAC TF mit erhöhter Genexpression während der Seneszenz, wurde erstmals in Mutanten mit verzögerte Seneszenz beschrieben, die molekularen Mechanismen, wie ORE1 die Seneszenz kontrolliert und die Stoffwechselwege reguliert, sind aber noch weitgehend unbekannt. Die Arbeiten im Rahmen dieser Dissertation wurden durchgeführt, um einen tieferen Einblick in die Regulationsmechanismen von ORE1 auf natürliche, dunkel induzierte sowie Salzstress-induzierte Seneszenz zu erhalten. Ergebnisse von Untersuchungen an zwei unterschiedlichen Pflanzenspezies (Arabidopsis thalinana und Nicotiana tabacum) deuten auf ein ähnliches Expressionsmuster von ORE1 während der natürlichen als auch der Salz-induzierten Seneszenz hin. In der Promotorregion von ORE1 wurde ein für natürliche Seneszenz charakteristisches Muster identifiziert. In vivo Analysen ergaben darüber hinaus. Hinweise auf zwei weitere ORE1 Regulatoren. Debei handelt es sich umeinen weiteren NAC TF (ATAF1) und (ii) CKOR, einer Calcium-abhängige Protein-Kinase (CDPK).In weiteren Studien wurden sechs Gene identifiziert, die durch ORE1 reguliert werden. In den Promotoren dieser Gene wurden entsprechende Bindestellen für ORE1 lokalisiert. Die ORE1-Bindung an die Promotoren wurde daraufhin sowohl in vitro als auch in vivo verifiziert. Zwei dieser Gene, die BIFUNCTIONAL Nuclease I (BFNI) und VND-Interacting2 (VNI2), wurden zudem auf molekularer und physiologischer Ebene untersucht. KW - Blattalterung KW - Transkriptionsfaktor KW - Regulationsweg KW - Leaf senescence KW - transcription factor KW - regulatory pathway Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-62646 ER - TY - JOUR A1 - Guljamow, Arthur A1 - Delissen, Friedmar A1 - Baumann, Otto A1 - Thuenemann, Andreas F. A1 - Dittmann-Thünemann, Elke T1 - Unique properties of eukaryote-type actin and profilin horizontally transferred to cyanobacteria JF - PLoS one N2 - A eukaryote-type actin and its binding protein profilin encoded on a genomic island in the cyanobacterium Microcystis aeruginosa PCC 7806 co-localize to form a hollow, spherical enclosure occupying a considerable intracellular space as shown by in vivo fluorescence microscopy. Biochemical and biophysical characterization reveals key differences between these proteins and their eukaryotic homologs. Small-angle X-ray scattering shows that the actin assembles into elongated, filamentous polymers which can be visualized microscopically with fluorescent phalloidin. Whereas rabbit actin forms thin cylindrical filaments about 100 mu m in length, cyanobacterial actin polymers resemble a ribbon, arrest polymerization at 510 lam and tend to form irregular multi-strand assemblies. While eukaryotic profilin is a specific actin monomer binding protein, cyanobacterial profilin shows the unprecedented property of decorating actin filaments. Electron micrographs show that cyanobacterial profilin stimulates actin filament bundling and stabilizes their lateral alignment into heteropolymeric sheets from which the observed hollow enclosure may be formed. We hypothesize that adaptation to the confined space of a bacterial cell devoid of binding proteins usually regulating actin polymerization in eukaryotes has driven the co-evolution of cyanobacterial actin and profilin, giving rise to an intracellular entity. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0029926 SN - 1932-6203 VL - 7 IS - 1 SP - 221 EP - 231 PB - PLoS CY - San Fransisco ER - TY - THES A1 - Künn, Steffen T1 - Unemployment and active labor market policy : new evidence on start-up subsidies, marginal employment and programs for youth unemployed T1 - Arbeitslosigkeit und die Rolle von aktiver Arbeitsmarktpolitik : neue Erkenntnisse zur Existenzgründungsförderung, geringfügiger Beschäftigung und Programmen für arbeitslose Jugendliche N2 - In industrialized economies such as the European countries unemployment rates are very responsive to the business cycle and significant shares stay unemployed for more than one year. To fight cyclical and long-term unemployment countries spend significant shares of their budget on Active Labor Market Policies (ALMP). To improve the allocation and design of ALMP it is essential for policy makers to have reliable evidence on the effectiveness of such programs available. Although the number of studies has been increased during the last decades, policy makers still lack evidence on innovative programs and for specific subgroups of the labor market. Using Germany as a case study, the dissertation aims at contributing in this way by providing new evidence on start-up subsidies, marginal employment and programs for youth unemployed. The idea behind start-up subsidies is to encourage unemployed individuals to exit unemployment by starting their own business. Those programs have compared to traditional programs of ALMP the advantage that not only the participant escapes unemployment but also might generate additional jobs for other individuals. Considering two distinct start-up subsidy programs, the dissertation adds three substantial aspects to the literature: First, the programs are effective in improving the employment and income situation of participants compared to non-participants in the long-run. Second, the analysis on effect heterogeneity reveals that the programs are particularly effective for disadvantaged groups in the labor market like low educated or low qualified individuals, and in regions with unfavorable economic conditions. Third, the analysis considers the effectiveness of start-up programs for women. Due to higher preferences for flexible working hours and limited part-time jobs, unemployed women often face more difficulties to integrate in dependent employment. It can be shown that start-up subsidy programs are very promising as unemployed women become self-employed which gives them more flexibility to reconcile work and family. Overall, the results suggest that the promotion of self-employment among the unemployed is a sensible strategy to fight unemployment by abolishing labor market barriers for disadvantaged groups and sustainably integrating those into the labor market. The next chapter of the dissertation considers the impact of marginal employment on labor market outcomes of the unemployed. Unemployed individuals in Germany are allowed to earn additional income during unemployment without suffering a reduction in their unemployment benefits. Those additional earnings are usually earned by taking up so-called marginal employment that is employment below a certain income level subject to reduced payroll taxes (also known as “mini-job”). The dissertation provides an empirical evaluation of the impact of marginal employment on unemployment duration and subsequent job quality. The results suggest that being marginal employed during unemployment has no significant effect on unemployment duration but extends employment duration. Moreover, it can be shown that taking up marginal employment is particularly effective for long-term unemployed, leading to higher job-finding probabilities and stronger job stability. It seems that mini-jobs can be an effective instrument to help long-term unemployed individuals to find (stable) jobs which is particularly interesting given the persistently high shares of long-term unemployed in European countries. Finally, the dissertation provides an empirical evaluation of the effectiveness of ALMP programs to improve labor market prospects of unemployed youth. Youth are generally considered a population at risk as they have lower search skills and little work experience compared to adults. This results in above-average turnover rates between jobs and unemployment for youth which is particularly sensitive to economic fluctuations. Therefore, countries spend significant resources on ALMP programs to fight youth unemployment. However, so far only little is known about the effectiveness of ALMP for unemployed youth and with respect to Germany no comprehensive quantitative analysis exists at all. Considering seven different ALMP programs, the results show an overall positive picture with respect to post-treatment employment probabilities for all measures under scrutiny except for job creation schemes. With respect to effect heterogeneity, it can be shown that almost all programs particularly improve the labor market prospects of youths with high levels of pretreatment schooling. Furthermore, youths who are assigned to the most successful employment measures have much better characteristics in terms of their pre-treatment employment chances compared to non-participants. Therefore, the program assignment process seems to favor individuals for whom the measures are most beneficial, indicating a lack of ALMP alternatives that could benefit low-educated youths. N2 - Zur Verbesserung der Arbeitsmarktchancen arbeitsloser Personen und damit zur Bekämpfung von Arbeitslosigkeit werden innerhalb der Europäischen Union jedes Jahr beträchtliche Summen für Maßnahmen der aktiven Arbeitsmarktpolitik (AAP) aufgewendet. Vor diesem Hintergrund ergibt sich die Frage nach der Effektivität dieser Programme. Obwohl in den vergangenen Jahren zahlreiche empirische Evaluationsstudien durchgeführt und hierdurch wesentliche Erkenntnisse über die Wirksamkeit von AAP gewonnen wurden, bestehen noch stets unerforschte bzw. nur unzureichend erforschte Bereiche, wie zum Beispiel für innovative Programme oder für Untergruppen am Arbeitsmarkt. Hierin liegt der Beitrag der Dissertationsschrift. Am Beispiel von Deutschland werden neue Erkenntnisse zur Wirksamkeit der Existenzgründungsförderung, der geringfügigen Beschäftigung sowie der Programme für arbeitslose Jugendliche geliefert. Mit Einführung des Existenzgründungszuschusses (Ich-AG) im Rahmen der Hartz-Reformen, standen gründungswilligen Arbeitslosen, zusammen mit dem bereits seit Mitte der Achtziger Jahre bekannten Überbrückungsgeld, zwischen 2003 und 2006 zwei Förderprogramme zur Verfügung. Beide Programme umfassen eine monetäre Förderung während der Gründungsphase, um arbeitslosen Personen den Weg in die berufliche Selbständigkeit zu erleichtern. Die Analyse der beiden Programme zeigt deutlich, dass die intendierten Ziele, d.h. die Verbesserung der Beschäftigungschancen sowie der Einkommenssituation der Teilnehmer, erreicht wurden. Es zeigt sich weiter, dass beide Programme insbesondere effektiv für benachteiligte Gruppen am Arbeitsmarkt, wie z.B. Geringqualifizierte, sowie in Regionen mit eher schlechten ökonomischen Bedingungen sind. Aber auch die getrennte Analyse für Frauen zieht eine positive Bilanz. Hier erweist sich die Förderung als besonders wirksam, da die berufliche Selbständigkeit (im Gegensatz zur abh. Beschäftigung) anscheinend eine bessere Vereinbarkeit von Familie und Beruf ermöglicht. Abschließend lässt sich somit feststellen, dass die Förderung der beruflichen Selbständigkeit eine sinnvolle Strategie darstellt, da insbesondere bestehende Hürden für benachteiligte Gruppen am Arbeitsmarkt beseitigt und diese Personen langfristig in den Arbeitsmarkt integriert werden. Im nächsten Abschnitt der Dissertationsschrift wird die Aufnahme einer geringfügigen Beschäftigung während der Arbeitslosigkeit untersucht. In Deutschland können arbeitslose Personen bis zu 15 Stunden/Woche eine Beschäftigung aufnehmen, wobei ein Zuverdienst bis 165 Euro/Monat keine Auswirkung auf den Bezug von Arbeitslosengeld hat. Hierzu greifen arbeitslose Personen insbesondere auf die geringfügige Beschäftigung (genannt „Mini-Job“) zurück, da diese für die Arbeitslosen selbst abgabenfrei ist und Arbeitgeber nur einen reduzierten Beitrag zur Sozialversicherung sowie Einkommensteuer zahlen. Das erhöhte Einkommensniveau während der Arbeitslosigkeit sowie der enge Kontakt zum Arbeitsmarkt können unterschiedliche Wirkungen generieren. Es zeigt sich, dass die Aufnahme einer geringfügigen Beschäftigung grundsätzlich keinen signifikanten Einfluss auf die Arbeitslosigkeitsdauer hat, jedoch im Anschluss an die Arbeitslosigkeit zu längeren Beschäftigungsphasen führt. Die Untersuchung der Effektheterogenität zeigt, dass die geringfügige Beschäftigung während der Arbeitslosigkeit die Arbeitslosigkeitsdauer für Langzeitarbeitslose verkürzt und zu insgesamt stabileren Beschäftigungsphasen für diese Personengruppe führt. Das Ergebnis ist von hoher politischer Relevanz, da die Möglichkeit einer Zusatzbeschäftigung während der Arbeitslosigkeit anscheinend ein effektives Instrument zur Bekämpfung von Langzeitarbeitslosigkeit darstellt. Abschließend beschäftigt sich die Dissertationsschrift mit der Untersuchung der Effektivität von AAP zur Verbesserung der Arbeitsmarktchancen von arbeitslosen Jugendlichen. Jugendliche sind im Gegensatz zu Erwachsenen häufiger von Arbeitslosigkeit betroffen, da sie über geringere Such- bzw. Arbeitserfahrung verfügen. Die Bekämpfung von Jugendarbeitslosigkeit steht daher im Fokus der AAP. Vor diesem Hintergrund ist es erstaunlich, dass bisher nur wenig über die Wirksamkeit von AAP für arbeitslose Jugendliche bekannt ist bzw. für Deutschland hierzu noch überhaupt keine Erkenntnisse existieren. Die Dissertationsschrift liefert nun erstmalig Evidenz zur Wirksamkeit von AAP für arbeitslose Jugendliche in Deutschland. Die untersuchten Programme (außer Arbeitsbeschaffungsmaßnahmen) erhöhen die Beschäftigungswahrscheinlichkeit der Teilnehmer gegenüber den Nicht-Teilnehmern. Allerdings zeigt sich auch, dass arbeitslose Jugendliche ohne bzw. mit Hauptschulabschluss weniger von einer Programmteilnahme profitieren als Jugendliche mit einer höheren Schulbildung. Hier scheint noch Optimierungsbedarf zu bestehen, indem die Ausgestaltung der AAP stärker auf die Bedürfnisse von geringqualifizierten Jugendlichen eingehen sollte. KW - aktive Arbeitsmarktpolitik KW - Evaluation KW - Mikroökonometrie KW - langfristige Effekte KW - Effektheterogenität KW - active labor market policy KW - evaluation KW - microeconometrics KW - long-term effects KW - effect heterogeneity Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-62718 ER - TY - BOOK A1 - Albrecht, Alexander A1 - Naumann, Felix T1 - Understanding cryptic schemata in large extract-transform-load systems N2 - Extract-Transform-Load (ETL) tools are used for the creation, maintenance, and evolution of data warehouses, data marts, and operational data stores. ETL workflows populate those systems with data from various data sources by specifying and executing a DAG of transformations. Over time, hundreds of individual workflows evolve as new sources and new requirements are integrated into the system. The maintenance and evolution of large-scale ETL systems requires much time and manual effort. A key problem is to understand the meaning of unfamiliar attribute labels in source and target databases and ETL transformations. Hard-to-understand attribute labels lead to frustration and time spent to develop and understand ETL workflows. We present a schema decryption technique to support ETL developers in understanding cryptic schemata of sources, targets, and ETL transformations. For a given ETL system, our recommender-like approach leverages the large number of mapped attribute labels in existing ETL workflows to produce good and meaningful decryptions. In this way we are able to decrypt attribute labels consisting of a number of unfamiliar few-letter abbreviations, such as UNP_PEN_INT, which we can decrypt to UNPAID_PENALTY_INTEREST. We evaluate our schema decryption approach on three real-world repositories of ETL workflows and show that our approach is able to suggest high-quality decryptions for cryptic attribute labels in a given schema. N2 - Extract-Transform-Load (ETL) Tools werden häufig beim Erstellen, der Wartung und der Weiterentwicklung von Data Warehouses, Data Marts und operationalen Datenbanken verwendet. ETL Workflows befüllen diese Systeme mit Daten aus vielen unterschiedlichen Quellsystemen. Ein ETL Workflow besteht aus mehreren Transformationsschritten, die einen DAG-strukturierter Graphen bilden. Mit der Zeit entstehen hunderte individueller ETL Workflows, da neue Datenquellen integriert oder neue Anforderungen umgesetzt werden müssen. Die Wartung und Weiterentwicklung von großen ETL Systemen benötigt viel Zeit und manuelle Arbeit. Ein zentrales Problem ist dabei das Verständnis unbekannter Attributnamen in Quell- und Zieldatenbanken und ETL Transformationen. Schwer verständliche Attributnamen führen zu Frustration und hohen Zeitaufwänden bei der Entwicklung und dem Verständnis von ETL Workflows. Wir präsentieren eine Schema Decryption Technik, die ETL Entwicklern das Verständnis kryptischer Schemata in Quell- und Zieldatenbanken und ETL Transformationen erleichtert. Unser Ansatz berücksichtigt für ein gegebenes ETL System die Vielzahl verknüpfter Attributnamen in den existierenden ETL Workflows. So werden gute und aussagekräftige "Decryptions" gefunden und wir sind in der Lage Attributnamen, die aus unbekannten Abkürzungen bestehen, zu "decrypten". So wird z.B. für den Attributenamen UNP_PEN_INT als Decryption UNPAIN_PENALTY_INTEREST vorgeschlagen. Unser Schema Decryption Ansatz wurde für drei ETL-Repositories evaluiert und es zeigte sich, dass unser Ansatz qualitativ hochwertige Decryptions für kryptische Attributnamen vorschlägt. T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 60 KW - Extract-Transform-Load (ETL) KW - Data Warehouse KW - Datenintegration KW - Extract-Transform-Load (ETL) KW - Data Warehouse KW - Data Integration Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-61257 SN - 978-3-86956-201-8 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Broß, Justus F. M. T1 - Understanding and leveraging the social physics of the blogosphere Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Zurell, Damaris A1 - Grimm, Volker A1 - Rossmanith, Eva A1 - Zbinden, Niklaus A1 - Zimmermann, Niklaus E. A1 - Schröder-Esselbach, Boris T1 - Uncertainty in predictions of range dynamics black grouse climbing the Swiss Alps JF - Ecography : pattern and diversity in ecology ; research papers forum N2 - Empirical species distribution models (SDMs) constitute often the tool of choice for the assessment of rapid climate change effects on species vulnerability. Conclusions regarding extinction risks might be misleading, however, because SDMs do not explicitly incorporate dispersal or other demographic processes. Here, we supplement SDMs with a dynamic population model 1) to predict climate-induced range dynamics for black grouse in Switzerland, 2) to compare direct and indirect measures of extinction risks, and 3) to quantify uncertainty in predictions as well as the sources of that uncertainty. To this end, we linked models of habitat suitability to a spatially explicit, individual-based model. In an extensive sensitivity analysis, we quantified uncertainty in various model outputs introduced by different SDM algorithms, by different climate scenarios and by demographic model parameters. Potentially suitable habitats were predicted to shift uphill and eastwards. By the end of the 21st century, abrupt habitat losses were predicted in the western Prealps for some climate scenarios. In contrast, population size and occupied area were primarily controlled by currently negative population growth and gradually declined from the beginning of the century across all climate scenarios and SDM algorithms. However, predictions of population dynamic features were highly variable across simulations. Results indicate that inferring extinction probabilities simply from the quantity of suitable habitat may underestimate extinction risks because this may ignore important interactions between life history traits and available habitat. Also, in dynamic range predictions uncertainty in SDM algorithms and climate scenarios can become secondary to uncertainty in dynamic model components. Our study emphasises the need for principal evaluation tools like sensitivity analysis in order to assess uncertainty and robustness in dynamic range predictions. A more direct benefit of such robustness analysis is an improved mechanistic understanding of dynamic species responses to climate change. Y1 - 2012 U6 - https://doi.org/10.1111/j.1600-0587.2011.07200.x SN - 0906-7590 VL - 35 IS - 7 SP - 590 EP - 603 PB - Wiley-Blackwell CY - Hoboken ER - TY - CHAP A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - Müller, Steffen A1 - Mayer, Frank T1 - Ultrasound evaluation of the patellar tendon cross-sectional area and its relation to maximum force T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 714 EP - 714 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Wang, E. A1 - Kirby, E. A1 - Furlong, K. P. A1 - van Soest, M. A1 - Xu, G. A1 - Shi, X. A1 - Kamp, P. J. J. A1 - Hodges, K. V. T1 - Two-phase growth of high topography in eastern Tibet during the Cenozoic JF - NATURE GEOSCIENCE N2 - High topography in eastern Tibet is thought to have formed when deep crust beneath the central Tibetan Plateau flowed towards the plateau margin, causing crustal thickening and surface uplift(1,2). Rapid exhumation starting about 10-15 million years ago is inferred to mark the onset of surface uplift and fluvial incision(3-6). Although geophysical data are consistent with weak crust capable of flow(7,8), it is unclear how the timing(9) and amount of deformation adjacent to the Sichuan Basin during the Cenozoic era can be explained in this way(10,11). Here we use thermochronology to measure the cooling histories of rocks exposed in a section that stretches vertically over 3 km adjacent to the Sichuan Basin. Our thermal models of exhumation-driven cooling show that these rocks, and hence the plateau margin, were subject to slow, steady exhumation during early Cenozoic time, followed by two pulses of rapid exhumation, one beginning 30-25 million years ago and a second 10-15 million years ago that continues to present. Our findings imply that significant topographic relief existed adjacent to the Sichuan Basin before the Indo-Asian collision. Furthermore, the onset of Cenozoic mountain building probably pre-dated development of the weak lower crust, implying that early topography was instead formed during thickening of the upper crust along faults. We suggest that episodes of mountain building may reflect distinct geodynamic mechanisms of crustal thickening. Y1 - 2012 U6 - https://doi.org/10.1038/NGEO1538 SN - 1752-0894 VL - 5 IS - 9 SP - 640 EP - 645 PB - NATURE PUBLISHING GROUP CY - NEW YORK ER - TY - JOUR A1 - Elsner, Robert A1 - Ullmann, Roland A1 - Heuer, Axel A1 - Menzel, Ralf A1 - Ostermeyer, Martin T1 - Two-dimensional modeling of transient gain gratings in saturable gain media JF - OPTICS EXPRESS N2 - A transient two-dimensional model describing degenerate four-wave mixing inside saturable gain media is presented. The new model is compared to existing one-dimensional models with their qualitative results confirmed. Large quantitative differences with respect to peak reflectivity and optimum pump fluence are observed. Furthermore, the influence of the beam focus size, the transverse position and the crossing angle on the reflectivity of the grating is investigated using the improved model. It is demonstrated that the phase conjugate reflectivity depends sensitively on the transverse features of the interacting beams with a transverse shift in the position of the pump beams yielding a threefold improvement in reflectivity. (C) 2012 Optical Society of America Y1 - 2012 U6 - https://doi.org/10.1364/OE.20.006887 SN - 1094-4087 VL - 20 IS - 7 SP - 6887 EP - 6896 PB - OPTICAL SOC AMER CY - WASHINGTON ER -