@article{XieXuGessneretal.2012, author = {Xie, Zai-Lai and Xu, Hai-Bing and Gessner, Andre and Kumke, Michael Uwe and Priebe, Magdalena and Fromm, Katharina M. and Taubert, Andreas}, title = {A transparent, flexible, ion conductive, and luminescent PMMA ionogel based on a Pt/Eu bimetallic complex and the ionic liquid [Bmim][N(Tf)(2)]}, series = {Journal of materials chemistry}, volume = {22}, journal = {Journal of materials chemistry}, number = {16}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {0959-9428}, doi = {10.1039/c2jm15862k}, pages = {8110 -- 8116}, year = {2012}, abstract = {Transparent, ion-conducting, luminescent, and flexible ionogels based on the room temperature ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl) imide [Bmim][N(Tf)(2)], a PtEu2 chromophore, and poly(methylmethacrylate) (PMMA) have been prepared. The thermal stability of the PMMA significantly increases with IL incorporation. In particular, the onset weight loss observed at ca. 229 degrees C for pure PMMA increases to 305 degrees C with IL addition. The ionogel has a high ionic conductivity of 10(-3) S cm(-1) at 373 K and exhibits a strong emission in the red with a long average luminescence decay time of tau = 890 mu s. The resulting material is a new type of soft hybrid material featuring useful thermal, optical, and ion transport properties.}, language = {en} } @article{KoethTierschAppelhansetal.2012, author = {Koeth, Anja and Tiersch, Brigitte and Appelhans, Dietmar and Gradzielski, Michael and C{\"o}lfen, Helmut and Koetz, Joachim}, title = {Synthesis of Core-Shell Gold Nanoparticles with Maltose-Modified Poly(Ethyleneimine)}, series = {Journal of dispersion science and technology}, volume = {33}, journal = {Journal of dispersion science and technology}, number = {1-3}, publisher = {Taylor \& Francis Group}, address = {Philadelphia}, issn = {0193-2691}, doi = {10.1080/01932691.2010.530084}, pages = {52 -- 60}, year = {2012}, abstract = {The synthesis of ultrafine gold nanoparticles in presence of maltose-modified hyperbranched poly(ethyleneimines) (PEI) is described. The polymer acted as both a reducing and stabilising agent in the particle formation process. The nanoparticles were characterized by means of dynamic light scattering (DLS), transmission electron microscopy (TEM), analytical ultracentrifugation (AUC), small-angle x-ray scattering (SAXS), and small-angle neutron scattering (SANS). The mechanism of nanoparticle formation can be described in two steps. The reduction process of the Au3+ ions located in the inner coil region of the hyperbranched PEI led to the formation of a compact gold core, and is accompanied by a collapse of the polymer coil. Therefore, in the subsequent reduction process a gold-polymer hybrid shell is formed. By using the PEI of higher molar mass, core-shell gold nanoparticles of about 3.6 nm size with a more narrow size distribution and special fluorescence behavior could be synthesized.}, language = {en} } @article{SumpfMaiwaldMulleretal.2012, author = {Sumpf, Bernd and Maiwald, Martin and Muller, Andre and Ginolas, Arnim and Haeusler, Karl and Erbert, Goetz and Traenkle, Guenther}, title = {Reliable operation for 14 500 h of a wavelength-stabilized Diode Laser System on a Microoptical Bench at 671 nm}, series = {IEEE transactions on components, packaging and manufacturing technology}, volume = {2}, journal = {IEEE transactions on components, packaging and manufacturing technology}, number = {1}, publisher = {Inst. of Electr. and Electronics Engineers}, address = {Piscataway}, issn = {2156-3950}, doi = {10.1109/TCPMT.2011.2171342}, pages = {116 -- 121}, year = {2012}, abstract = {Reliability tests for wavelength-stabilized compact diode laser systems emitting at 671 nm are presented. The devices were mounted on microoptical benches with the dimensions of 13 mm x 4 mm. Reflecting Bragg gratings were used for wavelength stabilization and emission width narrowing. The reliability tests were performed at 25 degrees C and at an output power up to 10 mW per micrometer stripe width of the gain medium. Reliable operation could be demonstrated over a test time up to 14 500 h at an output power up to 1.0 W. Environmental tests using random vibrations with acceleration up to 29 g were performed without deterioration of the devices.}, language = {en} } @article{GoebelWhiteTitiricietal.2012, author = {Goebel, Ronald and White, Robin J. and Titirici, Maria-Magdalena and Taubert, Andreas}, title = {Carbon-based ionogels tuning the properties of the ionic liquid via carbon-ionic liquid interaction}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {14}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {17}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/c2cp23929a}, pages = {5992 -- 5997}, year = {2012}, abstract = {The behavior of two ionic liquids (ILs), 1-ethyl-3-methylimidazolium dicyanamide [Emim][DCA] and 1-ethyl-3-methylimidazolium triflate [Emim][TfO], in (meso) porous carbonaceous hosts was investigated. Prior to IL incorporation into the host, the carbon matrix was thermally annealed between 180 and 900 degrees C to control carbon condensation and surface chemistry. The resulting materials have an increasing "graphitic'' carbon character with increasing treatment temperature, reflected in a modified behavior of the ILs when impregnated into the carbon host. The two ILs show significant changes in the thermal behavior as measured from differential scanning calorimetry; these changes can be assigned to anion-pi interaction between the IL anions and the pore wall surfaces of these flexible carbonaceous support materials.}, language = {en} } @article{RazzaqBehlFranketal.2012, author = {Razzaq, Muhammad Yasar and Behl, Marc and Frank, Ute and Koetz, Joachim and Szczerba, Wojciech and Lendlein, Andreas}, title = {Oligo(omega-pentadecalactone) decorated magnetic nanoparticles}, series = {Journal of materials chemistry}, volume = {22}, journal = {Journal of materials chemistry}, number = {18}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {0959-9428}, doi = {10.1039/c2jm16146j}, pages = {9237 -- 9243}, year = {2012}, abstract = {Hybrid magnetic nanoparticles (mgNP) with a magnetite core diameter of 10 +/- 1 nm surface functionalized with oligo(omega-pentadecalactone) (OPDL) oligomers with M-n between 1300 and 3300 g mol(-1) could be successfully prepared having OPDL grafted from 200 mg g(-1) to 2170 mg g(-1). The particles are dispersible in chloroform resulting in stable suspensions. Magnetic response against an external magnetic field proved the superparamagnetic nature of the particles with a low coercivity (B-c) value of 297 mu T. The combination of the advantageous superparamagnetism of the mgNP with the exceptional stability of OPDL makes these novel hybrid mgNP promising candidates as multifunctional building blocks for magnetic nanocomposites with tunable physical properties.}, language = {en} } @article{NeumannNoeskeTaubertetal.2012, author = {Neumann, Mike and Noeske, Robert and Taubert, Andreas and Tiersch, Brigitte and Strauch, Peter}, title = {Highly structured, biomorphous beta-SiC with high specific surface area from Equisetaceae}, series = {Journal of materials chemistry}, volume = {22}, journal = {Journal of materials chemistry}, number = {18}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {0959-9428}, doi = {10.1039/c2jm30253e}, pages = {9046 -- 9051}, year = {2012}, abstract = {Mesoporous, highly structured silicon carbide (beta-SiC) was synthesised from renewable plant materials (two Equisetaceae species) in a one-step carbothermal process at remarkably low temperatures down to 1200 degrees C. The SiC precursor is a silicon-carbon mixture with finely dispersed carbon prepared by pyrolysis of the organic plant matrix. Yields are 3 to 100\% (omega(Si/Si) related to the silicon deposited in the plant material), depending on reaction temperature and time. IR spectroscopy, X-ray diffraction, and nitrogen sorption prove the formation of high-purity beta-SiC with minor inorganic impurities after purification and a high specific surface area of up to 660 m(2) g(-1). Scanning electron microscopy shows that the plant morphology is maintained in the final SiC. Sedimentation analysis finds a mean particle size (diameters d(50)) of 20 mu m.}, language = {en} } @article{NeyerFelberGebhardt2012, author = {Neyer, Franz J. and Felber, Juliane and Gebhardt, Claudia}, title = {Development and validation of a brief measure of technology commitment}, series = {Diagnostica}, volume = {58}, journal = {Diagnostica}, number = {2}, publisher = {Hogrefe}, address = {G{\"o}ttingen}, issn = {0012-1924}, doi = {10.1026/0012-1924/a000067}, pages = {87 -- 99}, year = {2012}, abstract = {The authors propose a model of technology commitment that describes individual differences in the willingness of technology use in terms of three facets: technology acceptance, technology competence, technology control. It is assumed that technology commitment predicts adaptive technology use especially in old age. Data from three studies (N = 825 participants) support the conceptual distinction of the constructs and confirm the psychometric properties of the newly constructed scale. Construct validity was established via correlations with theoretically related constructs (technology use, personality, successful aging, health) as well as concurrently vis-a-vis other measures of technology acceptance.}, language = {de} } @article{SchmidtElizarov2012, author = {Schmidt, Bernd and Elizarov, Nelli}, title = {Selective arene functionalization through sequential oxidative and non-oxidative Heck reactions}, series = {Chemical communications}, volume = {48}, journal = {Chemical communications}, number = {36}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1359-7345}, doi = {10.1039/c2cc30752a}, pages = {4350 -- 4352}, year = {2012}, abstract = {A sequence of acetamide directed oxidative Heck reaction and deacetylation-diazotation-Heck coupling allows the traceless removal of the acetamide group and its dual exploitation as a catalyst directing group and a leaving group.}, language = {en} } @article{GuetschowNesmeWerner2012, author = {Guetschow, Johannes and Nesme, Vincent and Werner, Reinhard F.}, title = {Self-similarity of cellular automata on abelian groups}, series = {Journal of cellular automata}, volume = {7}, journal = {Journal of cellular automata}, number = {2}, publisher = {Old City Publishing Science}, address = {Philadelphia}, issn = {1557-5969}, pages = {83 -- 113}, year = {2012}, abstract = {It is well known that the spacetime diagrams of some cellular automata have a self-similar fractal structure: for instance Wolfram's rule 90 generates a Sierpinski triangle. Explaining the self-similarity of the spacetime diagrams of cellular automata is a well-explored topic, but virtually all of the results revolve around a special class of automata, whose typical features include irreversibility, an alphabet with a ring structure, a global evolution that is a ring homomorphism, and a property known as (weakly) p-Fermat. The class of automata that we study in this article has none of these properties. Their cell structure is weaker, as it does not come with a multiplication, and they are far from being p-Fermat, even weakly. However, they do produce self-similar spacetime diagrams, and we explain why and how.}, language = {en} } @article{KeehnerFischer2012, author = {Keehner, Madeleine and Fischer, Martin H.}, title = {Unusual bodies, uncommon behaviors individual and group differences in embodied cognition in spatial tasks}, series = {Spatial cognition and computation}, volume = {12}, journal = {Spatial cognition and computation}, number = {2-3}, publisher = {Taylor \& Francis Group}, address = {Philadelphia}, issn = {1387-5868}, doi = {10.1080/13875868.2012.659303}, pages = {71 -- 82}, year = {2012}, abstract = {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.}, language = {en} } @article{ZhongMetwalliKauneetal.2012, author = {Zhong, Qi and Metwalli, Ezzeldin and Kaune, Gunar and Rawolle, Monika and Bivigou Koumba, Achille Mayelle and Laschewsky, Andr{\´e} and Papadakis, Christine M. and Cubitt, Robert and M{\"u}ller-Buschbaum, Peter}, title = {Switching kinetics of thin thermo-responsive hydrogel films of poly(monomethoxy-diethyleneglycol-acrylate) probed with in situ neutron reflectivity}, series = {Soft matter}, volume = {8}, journal = {Soft matter}, number = {19}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1744-683X}, doi = {10.1039/c2sm25401h}, pages = {5241 -- 5249}, year = {2012}, abstract = {The switching kinetics of thin thermo-responsive hydrogel films of poly(monomethoxy-diethyleneglycol-acrylate) (PMDEGA) are investigated. Homogeneous and smooth PMDEGA films with a thickness of 35.9 nm are prepared on silicon substrates by spin coating. As probed with white light interferometry, PMDEGA films with a thickness of 35.9 nm exhibit a phase transition temperature of the lower critical solution temperature (LCST) type of 40 degrees C. In situ neutron reflectivity is performed to investigate the thermo-responsive behavior of these PMDEGA hydrogel films in response to a sudden thermal stimulus in deuterated water vapor atmosphere. The collapse transition proceeds in a complex way which can be seen as three steps. The first step is the shrinkage of the initially swollen film by a release of water. In the second step the thickness remains constant with water molecules embedded in the film. In the third step, perhaps due to a conformational rearrangement of the collapsed PMDEGA chains, water is reabsorbed from the vapor atmosphere, thereby giving rise to a relaxation process. Both the shrinkage and relaxation processes can be described by a simple model of hydrogel deswelling.}, language = {en} } @article{KrauseLiesenjohann2012, author = {Krause, E. Tobias and Liesenjohann, Thilo}, title = {Predation pressure and food abundance during early life alter risk-taking behaviour and growth of guppies (Poecilia reticulata)}, series = {Behaviour : an international journal of behavioural biology}, volume = {149}, journal = {Behaviour : an international journal of behavioural biology}, number = {1}, publisher = {Brill}, address = {Leiden}, issn = {0005-7959}, doi = {10.1163/156853912X623748}, pages = {1 -- 14}, year = {2012}, abstract = {The trade-off between predation risk and the need to feed is one of the major constraints animals have to cope with. Virtually all animals have a higher risk of being preyed upon when being active (e.g., searching for food or mating partners), compared with being inactive (e.g., staying at their burrows, nests, etc.). Yet, staying safe leads to a higher risk of starvation and may reduce reproductive success and body growth. Hence selection on behaviour optimizing the search, handling and digestion of food while avoiding the risk of predation is strong and should lead to strategies maximising survival chances and inclusive fitness. These facts call for integrative studies manipulating both, abundance of food and predation risk in a factorial set up, analysing the effects of both factors on behaviour and physiological parameters. We present results of a 2 x 2 factorial experiment, manipulating risk of predation and food abundance in guppies. We found that the two factors have an additive effect on body growth, but that predation risk by a pike cichlid is the main factor affecting the expression of behavioural strategies in guppies. Low food availability and high predation risk led to lower body growth. High predation risk affected swimming depth and risk sensitivity of guppies and might represent adaptive behavioural changes to the environmental context experienced in early life. Our study shows that integrative studies, analysing multiple interdependent and interconnected factors in the wild and in the lab are needed to further understand animal behaviour and development.}, language = {en} } @article{JanewaGhoshScheffler2012, author = {Janewa, Vanessa Sch{\"o}nfeld and Ghosh, Arnab and Scheffler, Christiane}, title = {Comparison of BMI and percentage of body fat of Indian and German children and adolescents}, series = {Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft f{\"u}r Anthropologie}, volume = {69}, journal = {Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft f{\"u}r Anthropologie}, number = {2}, publisher = {Schweizerbart}, address = {Stuttgart}, issn = {0003-5548}, doi = {10.1127/0003-5548/2012/0170}, pages = {175 -- 187}, year = {2012}, abstract = {Today, serious health problems as overweight and obesity are not just constricted to the developed world, but also increase in the developing countries (Prentice 2006, Ramachandram et al. 2002). Focusing on this issue, BMI and percentage of body fat were compared in 2094 schoolchildren from two cross-sectional studies from India and Germany investigated in 2008 and 2009. The German children are in all age groups significantly taller, whereas the Indian children show higher values in BMI (e.g. 12 years: Indian: around 22 kg/m(2); German: around 19 kg/m(2)) and in the percentage of body fat (e.g. 12 years: Indian: around 27 \%; German: around 18-20\%) in most of the investigated age groups. The Indian children have significantly higher BMI between 10 and 13 (boys) respectively 14 years (girls). Indian children showed significant higher percentage of body fat between 10 and 15 years (boys) and between 8 and 16 years (girls). The difference in overweight between Indian and German children was strongest at 11 (boys) and 12 (girls) years: 70 \% of the Indian but 20\% of the German children were classified as overweight. In countries such as India that undergo nutritional transition, a rapid increase in obesity and overweight is observed. In contrast to the industrialized countries, the risk of overweight in developing countries is associated with high socioeconomic status. Other reasons of the rapid increase of overweight in the developing countries caused by different environmental or genetic factors are discussed.}, language = {en} } @article{HermanussenLiebermanJanewaetal.2012, author = {Hermanussen, Michael and Lieberman, Leslie Su and Janewa, V. Schoenfeld and Scheffler, Christiane and Ghosh, Arunava and Bogin, Barry and Godina, Elena and Kaczmarek, M. and El-Shabrawi, M. and Salama, E. E. and R{\"u}hli, Frank J. and Staub, Kaspar and Woitek, U. and Blaha, Pawel and Aßmann, Christian and van Buuren, Stef and Lehmann, A. and Satake, T. and Thodberg, H. H. and Jopp, E. and Kirchengast, S. and Tutkuviene, J. and McIntyre, M. H. and Wittwer-Backofen, U. and Boldsen, Jesper L. and Martin, D. D. and Meier, J.}, title = {Diversity in auxology between theory and practice}, series = {Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft f{\"u}r Anthropologie}, volume = {69}, journal = {Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft f{\"u}r Anthropologie}, number = {2}, publisher = {Schweizerbart}, address = {Stuttgart}, issn = {0003-5548}, doi = {10.1127/0003-5548/2012/0133}, pages = {159 -- 174}, year = {2012}, abstract = {Auxology has developed from mere describing child and adolescent growth into a vivid and interdisciplinary research area encompassing human biologists, physicians, social scientists, economists and biostatisticians. The meeting illustrated the diversity in auxology, with the various social, medical, biological and biostatistical aspects in studies on child growth and development.}, language = {en} } @article{NagyTrautweinMaaz2012, author = {Nagy, Gabriel and Trautwein, Ulrich and Maaz, Kai}, title = {Ability and interest profiles at the end of lower secondary school structure, specification, and associations with educational choices}, series = {Zeitschrift f{\"u}r p{\"a}dagogische Psychologie.}, volume = {26}, journal = {Zeitschrift f{\"u}r p{\"a}dagogische Psychologie.}, number = {2}, publisher = {Hogrefe}, address = {Bern}, issn = {1010-0652}, doi = {10.1024/1010-0652/a000063}, pages = {79 -- 99}, year = {2012}, abstract = {This paper investigates the role of ability profiles and profiles of vocational interests at the transition from "Realschule" (lower secondary level) into the academic and vocational oriented "Gymnasium" (upper secondary track) school. Based on Guttman's (1954) radex model of cognitive and academic abilities as well as Holland's (1997) circumplex model of vocational interests, we developed statistical models for assessing individual differences in intraindividual profiles. The empirical results underscore the validity of our profile approach. Particularly (1) profiles derived on basis of test scores, grades, and interests were associated with all educational choices under consideration, and (2) decisions for different gymnasia types were systematically and meaningfully associated with individual profile parameters. In addition (3) criterion correlations of interest and ability measures could be explained by individual profile parameters.}, language = {de} } @article{Dunst2012, author = {Dunst, Alexander}, title = {After trauma time and affect in american culture beyond 9/11}, series = {Parallax}, volume = {18}, journal = {Parallax}, number = {2}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1353-4645}, doi = {10.1080/13534645.2012.672244}, pages = {56 -- 71}, year = {2012}, language = {en} } @article{ParedesBooAmoretal.2012, author = {Paredes, E. G. and Boo, M. and Amor, M. and Bruguera, J. D. and D{\"o}llner, J{\"u}rgen Roland Friedrich}, title = {Extended hybrid meshing algorithm for multiresolution terrain models}, series = {International journal of geographical information science}, volume = {26}, journal = {International journal of geographical information science}, number = {5}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1365-8816}, doi = {10.1080/13658816.2011.615317}, pages = {771 -- 793}, year = {2012}, abstract = {Hybrid terrains are a convenient approach for the representation of digital terrain models, integrating heterogeneous data from different sources. In this article, we present a general, efficient scheme for achieving interactive level-of-detail rendering of hybrid terrain models, without the need for a costly preprocessing or resampling of the original data. The presented method works with hybrid digital terrains combining regular grid data and local high-resolution triangulated irregular networks. Since grid and triangulated irregular network data may belong to different datasets, a straightforward combination of both geometries would lead to meshes with holes and overlapping triangles. Our method generates a single multiresolution model integrating the different parts in a coherent way, by performing an adaptive tessellation of the region between their boundaries. Hence, our solution is one of the few existing approaches for integrating different multiresolution algorithms within the same terrain model, achieving a simple interactive rendering of complex hybrid terrains.}, language = {en} } @article{HerfurthdeMolinaWielandetal.2012, author = {Herfurth, Christoph and de Molina, Paula Malo and Wieland, Christoph and Rogers, Sarah and Gradzielski, Michael and Laschewsky, Andr{\´e}}, title = {One-step RAFT synthesis of well-defined amphiphilic star polymers and their self-assembly in aqueous solution}, series = {Polymer Chemistry}, volume = {3}, journal = {Polymer Chemistry}, number = {6}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/c2py20126g}, pages = {1606 -- 1617}, year = {2012}, abstract = {Multifunctional chain transfer agents for RAFT polymerisation were designed for the one-step synthesis of amphiphilic star polymers. Thus, hydrophobically end-capped 3- and 4-arm star polymers, as well as linear ones for reference, were made of the hydrophilic monomer N,N-dimethylacrylamide (DMA) in high yield with molar masses up to 150 000 g mol(-1), narrow molar mass distribution (PDI <= 1.2) and high end group functionality (similar to 90\%). The associative telechelic polymers form transient networks of interconnected aggregates in aqueous solution, thus acting as efficient viscosity enhancers and rheology modifiers, eventually forming hydrogels. The combination of dynamic light scattering (DLS), small angle neutron scattering (SANS) and rheology experiments revealed that several molecular parameters control the structure and therefore the physical properties of the aggregates. In addition to the size of the hydrophilic block (maximum length for connection) and the length of the hydrophobic alkyl chain ends (stickiness), the number of arms (functionality) proved to be a key parameter.}, language = {en} } @article{GuttZurellBracegridleetal.2012, author = {Gutt, Julian and Zurell, Damaris and Bracegridle, Thomas J. and Cheung, William and Clark, Melody S. and Convey, Peter and Danis, Bruno and David, Bruno and De Broyer, Claude and di Prisco, Guido and Griffiths, Huw and Laffont, Remi and Peck, Lloyd S. and Pierrat, Benjamin and Riddle, Martin J. and Saucede, Thomas and Turner, John and Verde, Cinzia and Wang, Zhaomin and Grimm, Volker}, title = {Correlative and dynamic species distribution modelling for ecological predictions in the Antarctic a cross-disciplinary concept}, series = {Polar research : a Norwegian journal of Polar research}, volume = {31}, journal = {Polar research : a Norwegian journal of Polar research}, number = {6}, publisher = {Co-Action Publ.}, address = {Jarfalla}, issn = {0800-0395}, doi = {10.3402/polar.v31i0.11091}, pages = {23}, year = {2012}, abstract = {Developments of future scenarios of Antarctic ecosystems are still in their infancy, whilst predictions of the physical environment are recognized as being of global relevance and corresponding models are under continuous development. However, in the context of environmental change simulations of the future of the Antarctic biosphere are increasingly demanded by decision makers and the public, and are of fundamental scientific interest. This paper briefly reviews existing predictive models applied to Antarctic ecosystems before providing a conceptual framework for the further development of spatially and temporally explicit ecosystem models. The concept suggests how to improve approaches to relating species' habitat description to the physical environment, for which a case study on sea urchins is presented. In addition, the concept integrates existing and new ideas to consider dynamic components, particularly information on the natural history of key species, from physiological experiments and biomolecular analyses. Thereby, we identify and critically discuss gaps in knowledge and methodological limitations. These refer to process understanding of biological complexity, the need for high spatial resolution oceanographic data from the entire water column, and the use of data from biomolecular analyses in support of such ecological approaches. Our goal is to motivate the research community to contribute data and knowledge to a holistic, Antarctic-specific, macroecological framework. Such a framework will facilitate the integration of theoretical and empirical work in Antarctica, improving our mechanistic understanding of this globally influential ecoregion, and supporting actions to secure this biodiversity hotspot and its ecosystem services.}, language = {en} } @article{DebatinMoellmerMondaletal.2012, author = {Debatin, Franziska and M{\"o}llmer, Jens and Mondal, Suvendu Sekhar and Behrens, Karsten and M{\"o}ller, Andreas and Staudt, Reiner and Thomas, Arne and Holdt, Hans-J{\"u}rgen}, title = {Mixed gas adsorption of carbon dioxide and methane on a series of isoreticular microporous metal-organic frameworks based on 2-substituted imidazolate-4-amide-5-imidates}, series = {Journal of materials chemistry}, volume = {22}, journal = {Journal of materials chemistry}, number = {20}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {0959-9428}, doi = {10.1039/c2jm15811f}, pages = {10221 -- 10227}, year = {2012}, abstract = {In this work the adsorption of CO2 and CH4 on a series of isoreticular microporous metal-organic frameworks based on 2-substituted imidazolate-4-amide-5-imidates, IFP-1-IFP-6 (IFP Imidazolate Framework Potsdam), is studied firstly by pure gas adsorption at 273 K. All experimental isotherms can be nicely described by using the Toth isotherm model and show the preferred adsorption of CO2 over CH4. At low pressures the Toth isotherm equation exhibits a Henry region, wherefore Henry's law constants for CO2 and CH4 uptake could be determined and ideal selectivity (alpha CO2/CH4) has been calculated. Secondly, selectivities were calculated from mixture data by using nearly equimolar binary mixtures of both gases by a volumetric-chromatographic method to examine the IFPs. Results showed the reliability of the selectivity calculation. Values of (alpha CO2/CH4) around 7.5 for IFP-5 indicate that this material shows much better selectivities than IFP-1, IFP-2, IFP-3, IFP-4 and IFP-6 with slightly lower selectivity (alpha CO2/CH4) = 4-6. The preferred adsorption of CO2 over CH4 especially of IFP-5 and IFP-4 makes these materials suitable for gas separation application.}, language = {en} } @article{CostaBronstertdeAraujo2012, author = {Costa, A. C. and Bronstert, Axel and de Araujo, Jose Carlos}, title = {A channel transmission losses model for different dryland rivers}, series = {Hydrology and earth system sciences : HESS}, volume = {16}, journal = {Hydrology and earth system sciences : HESS}, number = {4}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1027-5606}, doi = {10.5194/hess-16-1111-2012}, pages = {1111 -- 1135}, year = {2012}, abstract = {Channel transmission losses in drylands take place normally in extensive alluvial channels or streambeds underlain by fractured rocks. They can play an important role in streamflow rates, groundwater recharge, freshwater supply and channel-associated ecosystems. We aim to develop a process-oriented, semi-distributed channel transmission losses model, using process formulations which are suitable for data-scarce dryland environments and applicable to both hydraulically disconnected losing streams and hydraulically connected losing(/gaining) streams. This approach should be able to cover a large variation in climate and hydro-geologic controls, which are typically found in dryland regions of the Earth. Our model was first evaluated for a losing/gaining, hydraulically connected 30 km reach of the Middle Jaguaribe River (MJR), Ceara, Brazil, which drains a catchment area of 20 000 km(2). Secondly, we applied it to a small losing, hydraulically disconnected 1.5 km channel reach in the Walnut Gulch Experimental Watershed (WGEW), Arizona, USA. The model was able to predict reliably the streamflow volume and peak for both case studies without using any parameter calibration procedure. We have shown that the evaluation of the hypotheses on the dominant hydrological processes was fundamental for reducing structural model uncertainties and improving the streamflow prediction. For instance, in the case of the large river reach (MJR), it was shown that both lateral stream-aquifer water fluxes and groundwater flow in the underlying alluvium parallel to the river course are necessary to predict streamflow volume and channel transmission losses, the former process being more relevant than the latter. Regarding model uncertainty, it was shown that the approaches, which were applied for the unsaturated zone processes (highly nonlinear with elaborate numerical solutions), are much more sensitive to parameter variability than those approaches which were used for the saturated zone (mathematically simple water budgeting in aquifer columns, including backwater effects). In case of the MJR-application, we have seen that structural uncertainties due to the limited knowledge of the subsurface saturated system interactions (i.e. groundwater coupling with channel water; possible groundwater flow parallel to the river) were more relevant than those related to the subsurface parameter variability. In case of the WEGW application we have seen that the non-linearity involved in the unsaturated flow processes in disconnected dryland river systems (controlled by the unsaturated zone) generally contain far more model uncertainties than do connected systems controlled by the saturated flow. Therefore, the degree of aridity of a dryland river may be an indicator of potential model uncertainty and subsequent attainable predictability of the system.}, language = {en} } @article{ScheweLevermannCheng2012, author = {Schewe, Jacob and Levermann, Anders and Cheng, Hai}, title = {A critical humidity threshold for monsoon transitions}, series = {Climate of the past : an interactive open access journal of the European Geosciences Union}, volume = {8}, journal = {Climate of the past : an interactive open access journal of the European Geosciences Union}, number = {2}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1814-9324}, doi = {10.5194/cp-8-535-2012}, pages = {535 -- 544}, year = {2012}, abstract = {Monsoon systems around the world are governed by the so-called moisture-advection feedback. Here we show that, in a minimal conceptual model, this feedback implies a critical threshold with respect to the atmospheric specific humidity q(o) over the ocean adjacent to the monsoon region. If q(o) falls short of this critical value q(o)(c), monsoon rainfall over land cannot be sustained. Such a case could occur if evaporation from the ocean was reduced, e.g. due to low sea surface temperatures. Within the restrictions of the conceptual model, we estimate q(o)(c) from present-day reanalysis data for four major monsoon systems, and demonstrate how this concept can help understand abrupt variations in monsoon strength on orbital timescales as found in proxy records.}, language = {en} } @article{SchadEngbert2012, author = {Schad, Daniel and Engbert, Ralf}, title = {The zoom lens of attention simulating shuffled versus normal text reading using the SWIFT model}, series = {Visual cognition}, volume = {20}, journal = {Visual cognition}, number = {4-5}, publisher = {Wiley}, address = {Hove}, issn = {1350-6285}, doi = {10.1080/13506285.2012.670143}, pages = {391 -- 421}, year = {2012}, abstract = {Assumptions on the allocation of attention during reading are crucial for theoretical models of eye guidance. The zoom lens model of attention postulates that attentional deployment can vary from a sharp focus to a broad window. The model is closely related to the foveal load hypothesis, i.e., the assumption that the perceptual span is modulated by the difficulty of the fixated word. However, these important theoretical concepts for cognitive research have not been tested quantitatively in eye movement models. Here we show that the zoom lens model, implemented in the SWIFT model of saccade generation, captures many important patterns of eye movements. We compared the model's performance to experimental data from normal and shuffled text reading. Our results demonstrate that the zoom lens of attention might be an important concept for eye movement control in reading.}, language = {en} } @article{SchellhasGrundmannEdelstein2012, author = {Schellhas, Bernd and Grundmann, Matthias and Edelstein, Wolfgang}, title = {Control beliefs and school achievement in the context of family socialization results of a longitudinal study}, series = {Psychologie in Erziehung und Unterricht : Zeitschrift f{\"u}r Forschung und Praxis}, volume = {59}, journal = {Psychologie in Erziehung und Unterricht : Zeitschrift f{\"u}r Forschung und Praxis}, number = {2}, publisher = {Reinhardt}, address = {M{\"u}nchen}, issn = {0342-183X}, pages = {93 -- 108}, year = {2012}, abstract = {In a longitudinal sample of Icelandic children (7.9-12-15 years; n=109) the developmental relations between of control beliefs (locus of control) and school achievement were examined on the background of child rearing practices, socialization conditions, and social class from childhood to adolescence. Results show that supportive and restrictive socialization conditions in social classes affect school achievement as well as the development of control beliefs. Supportive child rearing practices in upper class families encourage the development of internal control beliefs in adolescence, and are coincident with higher school achievement. On the other hand, restrictive child rearing practices appear independent of social class and generally hinder the development of internal control beliefs and positive school achievement. Results of a path model suggest a lagged relationship between school achievement and control beliefs. School achievement in childhood (ages 7 and 9) predicts internal control beliefs in adolescence.}, language = {de} } @article{LevermannAlbrechtWinkelmannetal.2012, author = {Levermann, Anders and Albrecht, Tanja and Winkelmann, Ricarda and Martin, Maria A. and Haseloff, Monika and Joughin, I.}, title = {Kinematic first-order calving law implies potential for abrupt ice-shelf retreat}, series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union}, volume = {6}, journal = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union}, number = {2}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1994-0416}, doi = {10.5194/tc-6-273-2012}, pages = {273 -- 286}, year = {2012}, abstract = {Recently observed large-scale disintegration of Antarctic ice shelves has moved their fronts closer towards grounded ice. In response, ice-sheet discharge into the ocean has accelerated, contributing to global sea-level rise and emphasizing the importance of calving-front dynamics. The position of the ice front strongly influences the stress field within the entire sheet-shelf-system and thereby the mass flow across the grounding line. While theories for an advance of the ice-front are readily available, no general rule exists for its retreat, making it difficult to incorporate the retreat in predictive models. Here we extract the first-order large-scale kinematic contribution to calving which is consistent with large-scale observation. We emphasize that the proposed equation does not constitute a comprehensive calving law but represents the first-order kinematic contribution which can and should be complemented by higher order contributions as well as the influence of potentially heterogeneous material properties of the ice. When applied as a calving law, the equation naturally incorporates the stabilizing effect of pinning points and inhibits ice shelf growth outside of embayments. It depends only on local ice properties which are, however, determined by the full topography of the ice shelf. In numerical simulations the parameterization reproduces multiple stable fronts as observed for the Larsen A and B Ice Shelves including abrupt transitions between them which may be caused by localized ice weaknesses. We also find multiple stable states of the Ross Ice Shelf at the gateway of the West Antarctic Ice Sheet with back stresses onto the sheet reduced by up to 90 \% compared to the present state.}, language = {en} } @article{DimitrovaKoppitz2012, author = {Dimitrova, Ilinka and Koppitz, J{\"o}rg}, title = {On the monoid of all partial order-preserving extensive transformations}, series = {Communications in algebra}, volume = {40}, journal = {Communications in algebra}, number = {5}, publisher = {Taylor \& Francis Group}, address = {Philadelphia}, issn = {0092-7872}, doi = {10.1080/00927872.2011.557813}, pages = {1821 -- 1826}, year = {2012}, abstract = {A partial transformation alpha on an n-element chain X-n is called order-preserving if x <= y implies x alpha <= y alpha for all x, y in the domain of alpha and it is called extensive if x <= x alpha for all x in the domain of alpha. The set of all partial order-preserving extensive transformations on X-n forms a semiband POEn. We determine the maximal subsemigroups as well as the maximal subsemibands of POEn.}, language = {en} } @article{SiTaubertMantionetal.2012, author = {Si, Satyabrata and Taubert, Andreas and Mantion, Alexandre and Rogez, Guillaume and Rabu, Pierre}, title = {Peptide-intercalated layered metal hydroxides effect of peptide chain length and side chain functionality on structural, optical and magnetic properties}, series = {Chemical science}, volume = {3}, journal = {Chemical science}, number = {6}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2041-6520}, doi = {10.1039/c2sc01087a}, pages = {1945 -- 1957}, year = {2012}, abstract = {New hybrid materials have been prepared by grafting synthetic peptides in the interlayer spacing of Cu(II) and Co(II) layered simple hydroxides (LSHs). The interlayer spacing of the hybrids depends on the peptide chain length; the dependence is specific for the copper and cobalt-based hybrids. This suggests a metal-or LSH-specific interaction of the peptides with the respective inorganic layers. When tyrosine is present in the peptide, its fluorescence is quenched after grafting the peptide to the LSH. Studies of the luminescence vs. pH indicate deprotonation of the tyrosine moieties to tyrosinate at high pH, accompanied by the onset of luminescence. The luminescence increases with increasing OH- concentration, suggesting an application of the hybrids as chemical sensors. Moreover, the peptides influence the magnetic properties of the hybrids. The copper-based hybrids behave antiferromagnetically and the cobalt-based hybrids are ferrimagnets.}, language = {en} } @article{KleinpeterKoch2012, author = {Kleinpeter, Erich and Koch, Andreas}, title = {Are lithium and sodium salts of N-(2-hydroxyphenyl)-salicylaldimine aromatic metalla-hetero[10]annulenes? An answer given by spatial magnetic properties (through space NMR shieldings-TSNMRS)}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {14}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {24}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/c2cp40501f}, pages = {8742 -- 8746}, year = {2012}, abstract = {The spatial magnetic properties (through space NMR shieldings-TSNMRS) of the enol tautomer of N-(2-hydroxyphenyl)-salicylaldimine, the lithium and sodium salts in comparison with cyclodecapentaene and pyrano[2,3-b] pyrrole were studied to answer this question.}, language = {en} } @article{KlaumuenzerKroenerLischkaetal.2012, author = {Klaum{\"u}nzer, Bastian and Kr{\"o}ner, Dominik and Lischka, Hans and Saalfrank, Peter}, title = {Non-adiabatic excited state dynamics of riboflavin after photoexcitation}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {14}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {24}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/c2cp40978j}, pages = {8693 -- 8702}, year = {2012}, abstract = {Flavins are chromophores in light-gated enzymes and therefore central in many photobiological processes. To unravel the optical excitation process as the initial, elementary step towards signal transduction, detailed ultrafast (femtosecond) experiments probing the photo-activation of flavins have been carried out recently [Weigel et al., J. Phys. Chem. B, 2011, 115, 3656-3680.]. The present paper contributes to a further understanding and interpretation of these experiments by studying the post-excitation vibrational dynamics of riboflavin (RF) and microsolvated riboflavin, RF center dot 4H(2)O, using first principles non-adiabatic molecular dynamics. By analyzing the characteristic atom motions and calculating time-resolved stimulated emission spectra following pi pi* excitation, it is found that after optical excitation C-N and C-C vibrations in the isoalloxazine rings of riboflavin set in. The Franck-Condon (vertically excited) state decays within about 10 fs, in agreement with experiment. Anharmonic coupling leads to Intramolecular Vibrational energy Redistribution (IVR) on the timescale of about 80-100 fs, first to (other) C-C stretching modes of the isoalloxazine rings, then by energy spread over the whole molecule, including low-frequency in-plane modes. The IVR is accompanied by a red-shift and broadening of the emission spectrum. When RF is microsolvated with four water molecules, an overall redshift of optical spectra by about 20 nm is observed but the relaxation dynamics is only slightly affected. For several trajectories, a tendency for hydrogen transfer from water to flavin-nitrogen (N-5) was found.}, language = {en} } @article{RoeselGrossart2012, author = {Roesel, Stefan and Grossart, Hans-Peter}, title = {Contrasting dynamics in activity and community composition of free-living and particle-associated bacteria in spring}, series = {Aquatic microbial ecology : international journal}, volume = {66}, journal = {Aquatic microbial ecology : international journal}, number = {2}, publisher = {Institute of Mathematical Statistics}, address = {Oldendorf Luhe}, issn = {0948-3055}, doi = {10.3354/ame01568}, pages = {169 -- +}, year = {2012}, abstract = {Phytoplankton development affects the community structure and dynamics of freshwater bacteria by changing the availability of nutrients, algal exudates and biological surfaces. To elucidate these effects of phytoplankton development in spring in oligotrophic Lake Stechlin (Germany), we measured limnological and biological parameters, including the bacterial community composition (BCC), at the depth of the highest chlorophyll a concentration. To increase the resolution of BCC measurements, we separated particle-associated (PA) and free-living (FL) bacteria using serial filtration through 5.0 and 0.2 mu m pore size filters, respectively. The BCC of ultramicrobacteria was also determined by collecting the 0.2 mu m filtrate on 0.1 mu m filters. Changes in the community composition of Bacteria and particularly of Actinobacteria, one of the most important bacterial groups in temperate freshwater habitats, were studied via DGGE analysis of PCR-amplified 16S rRNA gene fragments. Patterns in BCC dynamics of FL Bacteria and Actinobacteria remained fairly constant throughout the study period, while patterns of PA Bacteria were more variable over time. At the breakdown of the diatom spring bloom, bacterial production and abundance sharply increased, indicating a close coupling between heterotrophic bacteria and algal detritus. The succession in BCC revealed life-style dependent patterns related to specific environmental variables. Our results indicate independent dynamics of PA and FL Bacteria as well as Actinobacteria during succession of phytoplankton spring blooms. These differences in bacterial lifestyle can only be resolved when the PA and FL fractions of microorganisms are separated.}, language = {en} } @article{Hennemann2012, author = {Hennemann, Anja}, title = {The epistemic and evidential use of Spanish modal adverbs and verbs of cognitive attitude}, series = {Folia linguistica}, volume = {46}, journal = {Folia linguistica}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, issn = {0165-4004}, doi = {10.1515/FLIN.2012.5}, pages = {133 -- 170}, year = {2012}, abstract = {This article deals with Spanish modal adverbs and verbs of cognitive attitude (Capelli 2007) and their epistemic and/or evidential use. The article is based upon the hypothesis that the study of the use of these linguistic devices has to be highly context-sensitive, as it is not always (only) the sentence level that has to be looked at if one wants to find out whether a certain adverb or verb of cognitive attitude is used evidentially or epistemically. In this article, therefore, the context is used to determine which meaning aspects of an element are encoded and which are contributed by the context. The data were retrieved from the daily newspaper El Pais. Nevertheless, the present study is not a quantitative one, but rather a qualitative study. My corpus analysis indicates that it is not possible to differentiate between the linguistic categories of evidentiality and epistemic modality in every case, although it indeed is possible in the vast majority of cases. In verbs of cognitive attitude, evidentiality and epistemic modality seem to be two interwoven categories, while concerning modal adverbs it is usually possible to separate the categories and to distinguish between the different subtypes of evidentiality such as visual evidence, hearsay and inference.}, language = {en} } @article{OrejasLambers2012, author = {Orejas, Fernando and Lambers, Leen}, title = {Lazy graph transformation}, series = {Fundamenta informaticae}, volume = {118}, journal = {Fundamenta informaticae}, number = {1-2}, publisher = {IOS Press}, address = {Amsterdam}, issn = {0169-2968}, doi = {10.3233/FI-2012-706}, pages = {65 -- 96}, year = {2012}, abstract = {Applying an attributed graph transformation rule to a given object graph always implies some kind of constraint solving. In many cases, the given constraints are almost trivial to solve. For instance, this is the case when a rule describes a transformation G double right arrow H, where the attributes of H are obtained by some simple computation from the attributes of G. However there are many other cases where the constraints to solve may be not so trivial and, moreover, may have several answers. This is the case, for instance, when the transformation process includes some kind of searching. In the current approaches to attributed graph transformation these constraints must be completely solved when defining the matching of the given transformation rule. This kind of early binding is well-known from other areas of Computer Science to be inadequate. For instance, the solution chosen for the constraints associated to a given transformation step may be not fully adequate, meaning that later, in the search for a better solution, we may need to backtrack this transformation step. In this paper, based on our previous work on the use of symbolic graphs to deal with different aspects related with attributed graphs, including attributed graph transformation, we present a new approach that, based on the new notion of narrowing graph transformation rule, allows us to delay constraint solving when doing attributed graph transformation, in a way that resembles lazy computation. For this reason, we have called lazy this new kind of transformation. Moreover, we show that the approach is sound and complete with respect to standard attributed graph transformation. A running example, where a graph transformation system describes some basic operations of a travel agency, shows the practical interest of the approach.}, language = {en} } @article{EhrigGolasHabeletal.2012, author = {Ehrig, Hartmut and Golas, Ulrike and Habel, Annegret and Lambers, Leen and Orejas, Fernando}, title = {M-Adhesive Transformation Systems with Nested Application Conditions Part 2: Embedding, Critical Pairs and Local Confluence}, series = {Fundamenta informaticae}, volume = {118}, journal = {Fundamenta informaticae}, number = {1-2}, publisher = {IOS Press}, address = {Amsterdam}, issn = {0169-2968}, doi = {10.3233/FI-2012-705}, pages = {35 -- 63}, year = {2012}, abstract = {Graph transformation systems have been studied extensively and applied to several areas of computer science like formal language theory, the modeling of databases, concurrent or distributed systems, and visual, logical, and functional programming. In most kinds of applications it is necessary to have the possibility of restricting the applicability of rules. This is usually done by means of application conditions. In this paper, we continue the work of extending the fundamental theory of graph transformation to the case where rules may use arbitrary (nested) application conditions. More precisely, we generalize the Embedding theorem, and we study how local confluence can be checked in this context. In particular, we define a new notion of critical pair which allows us to formulate and prove a Local Confluence Theorem for the general case of rules with nested application conditions. All our results are presented, not for a specific class of graphs, but for any arbitrary M-adhesive category, which means that our results apply to most kinds of graphical structures. We demonstrate our theory on the modeling of an elevator control by a typed graph transformation system with positive and negative application conditions.}, language = {en} } @article{FeherWhelanMueller2012, author = {Feher, Kristen and Whelan, James and M{\"u}ller, Samuel}, title = {Exploring multicollinearity using a random matrix theory approach}, series = {Statistical applications in genetics and molecular biology}, volume = {11}, journal = {Statistical applications in genetics and molecular biology}, number = {3}, publisher = {De Gruyter}, address = {Berlin}, issn = {1544-6115}, doi = {10.1515/1544-6115.1668}, pages = {35}, year = {2012}, abstract = {Clustering of gene expression data is often done with the latent aim of dimension reduction, by finding groups of genes that have a common response to potentially unknown stimuli. However, what is poorly understood to date is the behaviour of a low dimensional signal embedded in high dimensions. This paper introduces a multicollinear model which is based on random matrix theory results, and shows potential for the characterisation of a gene cluster's correlation matrix. This model projects a one dimensional signal into many dimensions and is based on the spiked covariance model, but rather characterises the behaviour of the corresponding correlation matrix. The eigenspectrum of the correlation matrix is empirically examined by simulation, under the addition of noise to the original signal. The simulation results are then used to propose a dimension estimation procedure of clusters from data. Moreover, the simulation results warn against considering pairwise correlations in isolation, as the model provides a mechanism whereby a pair of genes with 'low' correlation may simply be due to the interaction of high dimension and noise. Instead, collective information about all the variables is given by the eigenspectrum.}, language = {en} } @article{SchmidtKrehlJablowski2012, author = {Schmidt, Bernd and Krehl, Stefan and Jablowski, Eric}, title = {Assisted tandem catalytic RCM-aromatization in the synthesis of pyrroles and furans}, series = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry}, volume = {10}, journal = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry}, number = {26}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1477-0520}, doi = {10.1039/c2ob25543j}, pages = {5119 -- 5130}, year = {2012}, abstract = {An assisted tandem catalytic transformation of diallyl amines and diallyl ethers into N-aryl pyrroles and furans, respectively, is described. The sequence relies on ring closing metathesis followed by dehydrogenation of the initially formed dihydropyrroles and dihydrofurans. Both steps are Ru-catalyzed, but the sequence requires only one precatalyst, because conversion of the metathesis catalyst into the dehydrogenation catalyst is achieved in situ, triggered by the oxidant tert-butyl hydroperoxide.}, language = {en} } @article{ScherlerStrecker2012, author = {Scherler, Dirk and Strecker, Manfred}, title = {Large surface velocity fluctuations of Biafo Glacier, central Karakoram, at high spatial and temporal resolution from optical satellite images}, series = {Journal of glaciology}, volume = {58}, journal = {Journal of glaciology}, number = {209}, publisher = {International Glaciological Society}, address = {Cambridge}, issn = {0022-1430}, doi = {10.3189/2012JoG11J096}, pages = {569 -- 580}, year = {2012}, abstract = {Despite global warming and unlike their Himalayan neighbours, glaciers in the Karakoram mountains do not show signs of significant retreat. Here we report high velocity variations of Biafo Glacier, central Karakoram, which occurred between 2001 and 2009 and which indicate considerable dynamics in its flow behaviour. We have generated a dense time series of glacier surface velocities, based on cross-correlation of optical satellite images, which clearly shows seasonal and interannual velocity variations, reaching 50\% in some places. The interannual velocity variations resemble the passing of a broad wave of high velocities, with peak velocities during 2005 and some diffusion down-glacier over a period of at least 4 years. High interannual velocity variations are also observed at other glaciers in the vicinity, suggesting a common cause, although these appear to partly comprise longer acceleration phases. Analysis of weather station data provides some indications of meteorological conditions that could have promoted sustained sliding events during this period, but this does not explain the wave-like nature of the acceleration at Biafo Glacier, and the regular, protracted velocity changes.}, language = {en} } @article{BraunMustafaNordtetal.2012, author = {Braun, Christina and Mustafa, Osama and Nordt, Anja and Pfeiffer, Simone and Peter, Hans-Ulrich}, title = {Environmental monitoring and management proposals for the Fildes Region, King George Island, Antarctica}, series = {Polar research : a Norwegian journal of Polar research}, volume = {31}, journal = {Polar research : a Norwegian journal of Polar research}, number = {209}, publisher = {Co-Action Publ.}, address = {Jarfalla}, issn = {0800-0395}, doi = {10.3402/polar.v31i0.18206}, pages = {18}, year = {2012}, abstract = {The Antarctic terrestrial environment is under increasing pressure from human activities. The Fildes Region is characterized by high biodiversity, but is also a major logistic centre for the northern Antarctic Peninsula. Different interests, from scientific research, nature conservation, protection of geological and historical values, station operations, transport logistics and tourism, regularly overlap in space and time. This has led to increasing conflict among the multiple uses of the region and breaches of the legal requirements for environmental protection that apply in the area. The aim of this study was to assess the impacts of human activities in the Fildes Region by monitoring the distribution of bird and seal breeding sites and recording human activities and their associated environmental impacts. Data from an initial monitoring period 2003-06 were compared with data from 2008-10. We observed similar or increased levels of air, land and ship traffic, but fewer violations of overflight limits near Antarctic Specially Protected Area No. 150 Ardley Island. Open waste dumping and oil contamination are still major environmental impacts. Scientific and outdoor leisure activities undertaken by station personnel are more frequent than tourist activities and are likely to have a commensurate level of environmental impact. Despite the initial success of some existing management measures, it is essential that scientific and environmental values continue to be safeguarded, otherwise environmental impacts will increase and the habitat will be further degraded. We argue that the Fildes Region should be considered for designation as an Antarctic Specially Managed Area, a measure that has proven effective for environmental management of vulnerable areas of the Antarctic.}, language = {en} } @article{SeifanSeifanJeltschetal.2012, author = {Seifan, Merav and Seifan, Tal and Jeltsch, Florian and Tielboerger, Katja}, title = {Combined disturbances and the role of their spatial and temporal properties in shaping community structure}, series = {Perspectives in plant ecology, evolution and systematics}, volume = {14}, journal = {Perspectives in plant ecology, evolution and systematics}, number = {3}, publisher = {Elsevier}, address = {Jena}, issn = {1433-8319}, doi = {10.1016/j.ppees.2011.11.003}, pages = {217 -- 229}, year = {2012}, abstract = {Disturbances are characteristic for many ecosystems. However, we still lack generalizations concerning their role in shaping communities, particularly when disturbances co-occur. To study such effects, we used a novel modeling approach that is unrestricted by a priori tradeoffs among specific plant traits, except for those generated by allocation principles. Thus, trait combinations were emergent properties associated with biotic and abiotic constraints. Specifically, we asked which traits dominate under specific disturbance regimes, whether single and combined disturbance regimes promote similar trait tradeoffs and how complex disturbance regimes affect species richness and functional diversity. Overall, disturbances' temporal properties governed the outcome of combined disturbances and were a stronger assortative force than spatial disturbance properties: low temporal predictability decreased seed-dispersability and dormancy, but increased competitive ability and disturbance tolerance. Evidence for tradeoffs between different colonization modes and between dormancy and disturbance tolerance were found, while surprisingly, the widely accepted colonization-competition tradeoff was not generated. Diversity was highest at intermediate disturbance intensity, but decreased monotonically with increasing unpredictability. In accordance with our results, future models should avoid restrictive assumptions about tradeoffs to generate robust and more general predictions about the role of disturbances for community dynamics.}, language = {en} } @article{ChenLiWangetal.2012, author = {Chen, You-Peng and Li, Jian and Wang, Zi-Neng and Reichetzeder, Christoph and Xu, Hao and Gong, Jian and Chen, Guang-Ji and Pfab, Thiemo and Xiao, Xiao-Min and Hocher, Berthold}, title = {Renin angiotensin aldosterone system and glycemia in pregnancy}, series = {Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion}, volume = {58}, journal = {Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion}, number = {5-6}, publisher = {Clin Lab Publ., Verl. Klinisches Labor}, address = {Heidelberg}, issn = {1433-6510}, pages = {527 -- 533}, year = {2012}, abstract = {Background: The renin-angiotensin-aldosterone system (RAAS) is involved in the pathogenesis of insulin resistance and type 2 diabetes in the general population. The RAAS is activated during pregnancy. However, it is unknown whether the RAAS contributes to glycemia in pregnant women. Methods: Plasma renin activity (PRA) and plasma aldosterone levels were quantified at delivery in 689 Chinese mothers. An oral glucose tolerance test in fasted women was performed in the second trimester of pregnancy. The diagnosis of gestational diabetes mellitus (GDM) and impaired glucose tolerance during pregnancy were made according to the guidelines of the Chinese Society of Obstetrics. Results: Plasma aldosterone was significantly higher in pregnant women with GDM as compared to those without impairment of glycemic control (normal pregnancies: 0.27 +/- 0.21 ng/mL, GDM: 0.36 +/- 0.30 ng/mL; p<0.05). Regression analyses revealed that PRA was negatively correlated with fasting blood glucose (FBG) (R-2 = 0.03, p = 0.007), whereas plasma aldosterone and aldosterone/PRA ratio were positively correlated with FBG (R-2 = 0.05, p<0.001 and R-2 = 0.03, p = 0.007, respectively). Multivariable regression analysis models considering relevant confounding factors confirmed these findings. Conclusions: This study demonstrated that fasting blood glucose in pregnant women is inversely correlated with the PRA, whereas plasma aldosterone showed a highly significant positive correlation with fasting blood glucose during pregnancy. Moreover, plasma aldosterone is significantly higher in pregnant women with GDM as compared to those women with normal glucose tolerance during pregnancy. Although causality cannot be proven in association studies, these data may indicate that the RAAS during pregnancy contributes to the pathogenesis of insulin resistance/new onset of diabetes during pregnancy.}, language = {en} } @article{VukicevicVukovicStoyanovetal.2012, author = {Vukicevic, Radovan and Vukovic, Ivana and Stoyanov, Hristiyan and Korwitz, Andreas and Pospiech, Doris and Kofod, Guggi and Loos, Katja and ten Brinke, Gerrit and Beuermann, Sabine}, title = {Poly(vinylidene fluoride)-functionalized single-walled carbon nanotubes for the preparation of composites with improved conductivity}, series = {Polymer Chemistry}, volume = {3}, journal = {Polymer Chemistry}, number = {8}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/c2py20166f}, pages = {2261 -- 2265}, year = {2012}, abstract = {The surface of single-walled carbon nanotubes (SWCNTs) was functionalized with azide-terminated poly(vinylidene fluoride) (PVDF). Functionalization was confirmed by dispersibility, Raman spectroscopy, and thermogravimetric analyses. Raman spectra show disordering of the SWCNTs, thus, strongly suggesting that PVDF was covalently attached to SWCNTs. Functionalized SWCNTs were mixed with commercially available PVDF in a twin-screw extruder and thin films were obtained by melt-pressing. Films containing 0.5 and 1 wt\% PVDF-functionalized SWCNTs exhibited significantly improved electrical conductivity compared to PVDF films containing pristine SWCNTs.}, language = {en} } @article{GirndtRieschSchroederetal.2012, author = {Girndt, Antje and Riesch, R{\"u}diger and Schr{\"o}der, Christiane and Sehlupp, Ingo and Plath, Martin and Tiedemann, Ralph}, title = {Multiple paternity in different populations of the sailfin molly, Poecilia latipinna}, series = {Animal biology}, volume = {62}, journal = {Animal biology}, number = {3}, publisher = {Brill}, address = {Leiden}, issn = {1570-7555}, doi = {10.1163/157075611X618192}, pages = {245 -- 262}, year = {2012}, abstract = {Rates of multiple paternities were investigated in the sailfin molly (Poecilia latipinna), using eight microsatellite loci. Genotyping was performed for offspring and mothers in 40 broods from four allopatric populations from the south-eastern U.S.A. along a geographic stretch of 1200 km in west-east direction and approximately 200 km from north to south. No significant differences regarding rates of multiple paternities were found between populations despite sample populations stemming from ecologically divergent habitats. Even the most conservative statistical approach revealed a minimum of 70\% of the broods being sired by at least two males, with an average of 1.80-2.95 putative fathers per brood. Within broods, one male typically sired far more offspring than would be expected under an assumed equal probability of all detected males siring offspring.}, language = {en} } @article{AydelottBaerHenneyTrzaskowskietal.2012, author = {Aydelott, Jennifer and Baer-Henney, Dinah and Trzaskowski, Maciej and Leech, Robert and Dick, Frederic}, title = {Sentence comprehension in competing speech dichotic sentence-word priming reveals hemispheric differences in auditory semantic processing}, series = {Language and cognitive processes}, volume = {27}, journal = {Language and cognitive processes}, number = {7-8}, publisher = {Wiley}, address = {Hove}, issn = {0169-0965}, doi = {10.1080/01690965.2011.589735}, pages = {1108 -- 1144}, year = {2012}, abstract = {This study examined the effects of competing speech on auditory semantic comprehension using a dichotic sentence-word priming paradigm. Lexical decision performance for target words presented in spoken sentences was compared in strongly and weakly biasing semantic contexts. Targets were either congruent or incongruent with the sentential bias. Sentences were presented to one auditory channel (right or left), either in isolation or with competing speech produced by a single talker of the same gender presented simultaneously. The competing speech signal was either presented in the same auditory channel as the sentence context, or in a different auditory channel, and was either meaningful (played forward) or unintelligible (time-reversed). Biasing contexts presented in isolation facilitated responses to congruent targets and inhibited responses to incongruent targets, relative to a neutral baseline. Facilitation priming was reduced or eliminated by competing speech presented in the same auditory channel, supporting previous findings that semantic activation is highly sensitive to the intelligibility of the context signal. Competing speech presented in a different auditory channel affected facilitation priming differentially depending upon ear of presentation, suggesting hemispheric differences in the processing of the attended and competing signals. Results were consistent with previous claims of a right ear advantage for meaningful speech, as well as with visual word recognition findings implicating the left hemisphere in the generation of semantic predictions and the right hemisphere in the integration of newly encountered words into the sentence-level meaning. Unlike facilitation priming, inhibition was relatively robust to the energetic and informational masking effects of competing speech and was not influenced by the strength of the contextual bias or the meaningfulness of the competing signal, supporting a two-process model of sentence priming in which inhibition reflects later-stage, expectancy-driven strategic processes that may benefit from perceptual reanalysis after initial semantic activation.}, language = {en} } @article{GoebelXieNeumannetal.2012, author = {Goebel, Ronald and Xie, Zai-Lai and Neumann, Mike and G{\"u}nter, Christina and Loebbicke, Ruben and Kubo, Shiori and Titirici, Maria-Magdalena and Giordano, Cristina and Taubert, Andreas}, title = {Synthesis of mesoporous carbon/iron carbide hybrids with unusually high surface areas from the ionic liquid precursor [Bmim][FeCl4]}, series = {CrystEngComm}, volume = {14}, journal = {CrystEngComm}, number = {15}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1466-8033}, doi = {10.1039/c2ce25064k}, pages = {4946 -- 4951}, year = {2012}, abstract = {Mesoporous carbon/iron carbide hybrid materials with surface areas reaching 800 m(2) g(-1) were synthesized via an exotemplating route using monolithic mesoporous silica as template and the ionic liquid 1-butyl-3-methylimidazolium tetrachloridoferrate(III) [Bmim][FeCl4] as carbon and iron source. After heat treatment (750 degrees C under argon) of the [Bmim][FeCl4] precursor confined within the silica matrix, the silica exotemplate was removed with HF leaving the mesoporous C/Fe3C hybrid behind. The surface areas and the pore sizes depend on the exotemplate and the surface areas a significantly larger than any other surface area reported for C/Fe3C hybrid materials so far. The approach is thus a prototype for the synthesis of high-surface area iron carbide-based hybrid materials with potential application in catalysis.}, language = {en} } @article{WieseFreywaldSchalowskietal.2012, author = {Wiese, Heike and Freywald, Ulrike and Schalowski, Soeren and Mayr, Katharina}, title = {The neighborhood-German corpus spontaneous language data from young urban residential areas}, series = {Deutsche Sprache : ds ; Zeitschrift f{\"u}r Theorie, Praxis, Dokumentation}, volume = {40}, journal = {Deutsche Sprache : ds ; Zeitschrift f{\"u}r Theorie, Praxis, Dokumentation}, number = {2}, publisher = {E. Schmidt}, address = {Berlin}, issn = {0340-9341}, pages = {97 -- 123}, year = {2012}, language = {de} } @article{AdamcikJeonKarczewskietal.2012, author = {Adamcik, Jozef and Jeon, Jae-Hyung and Karczewski, Konrad J. and Metzler, Ralf and Dietler, Giovanni}, title = {Quantifying supercoiling-induced denaturation bubbles in DNA}, series = {Soft matter}, volume = {8}, journal = {Soft matter}, number = {33}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1744-683X}, doi = {10.1039/c2sm26089a}, pages = {8651 -- 8658}, year = {2012}, abstract = {In both eukaryotic and prokaryotic DNA sequences of 30-100 base-pairs rich in AT base-pairs have been identified at which the double helix preferentially unwinds. Such DNA unwinding elements are commonly associated with origins for DNA replication and transcription, and with chromosomal matrix attachment regions. Here we present a quantitative study of local DNA unwinding based on extensive single DNA plasmid imaging. We demonstrate that long-lived single-stranded denaturation bubbles exist in negatively supercoiled DNA, at the expense of partial twist release. Remarkably, we observe a linear relation between the degree of supercoiling and the bubble size, in excellent agreement with statistical modelling. Furthermore, we obtain the full distribution of bubble sizes and the opening probabilities at varying salt and temperature conditions. The results presented herein underline the important role of denaturation bubbles in negatively supercoiled DNA for biological processes such as transcription and replication initiation in vivo.}, language = {en} } @article{KammerStarkePietruchaetal.2012, author = {Kammer, Stefan and Starke, Ines and Pietrucha, Andreas and Kelling, Alexandra and Mickler, Wulfhard and Schilde, Uwe and Dosche, Carsten and Kleinpeter, Erich and Holdt, Hans-J{\"u}rgen}, title = {1,12-Diazaperylene and 2,11-dialkylated-1,12-diazaperylene iridium(III) complexes [Ir((CN)-N-boolean AND)(2)((NN)-N-boolean AND)]PF6: new supramolecular assemblies}, series = {Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry}, volume = {41}, journal = {Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry}, number = {34}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1477-9226}, doi = {10.1039/c2dt30412k}, pages = {10219 -- 10227}, year = {2012}, abstract = {A series of new monocationic iridium(III) complexes [Ir((CN)-N-boolean AND)(2)((NN)-N-boolean AND)]PF6 with "large-surface" alpha,alpha'-diimin ligands (NN)-N-boolean AND (dap = 1,12-diazaperylene, dmedap = 2,11-dimethyl-1,12-diazaperylene, dipdap = 2,11-diisopropyl-1,12-diazaperylene) and different cyclometalating ligands (CN)-N-boolean AND (piq = 1-phenylisoquinoline, bzq = benzo[h]quinoline, ppz = 1-phenylpyrazole, thpy = 2-(2-thienyl)pyridine, ppy = 2-phenylpyridine, meppy = 2-(4-methylphenyl)pyridine, dfppy = 2-(2,4-difluorophenyl)pyridine) were synthesized. The solid structures of the complexes [Ir(piq)(2)(dap)]PF6, [Ir(bzq)(2)(dap)]PF6, [Ir(ppy)(2)(dipdap)]PF6, [Ir(piq)(2)(dmedap)]PF6, [Ir(ppy)(2)(dap)]PF6 and [Ir(ppz)(2)(dap)]PF6 are reported. In [Ir(piq)(2)(dap)]PF6, the dap ligand and one of the piq ligands of each cationic complex are involved in pi-pi stacking interactions forming supramolecular channels running along the crystallographic c axis. In the crystalline [Ir(bzq)(2)(dap)]PF6 pi-pi stacking interactions between the metal complexes lead to the formation of a 2D layer structure. In addition, CH-pi interactions were found in all compounds, which are what stabilizes the solid structure. In particular, a significant number of them were found in [Ir(piq)(2)(dap)]PF6 and [Ir(bzq)(2)(dap)]PF6. The crystal structures of [Ir(ppy)(2)(dipdap)]PF6 and [Ir(ppy)(2)(dmedap)]PF6 are also presented, being the first examples of bis-cyclometalated iridium(III) complexes with phenanthroline-type alpha,alpha'-diimin ligands bearing bulky alkyl groups in the neighbourhood of the N-donor atoms. These ligands implicate a distorted octahedral coordination geometry that in turn destabilized the Ir-N-N boolean AND N bonds. The new iridium (III) complexes are not luminescent. All compounds show an electrochemically irreversible anodic peak between 1.15 and 1.58 V, which is influenced by the different cyclometalated ligands. All of the new complexes show two reversible successive one-electron "large-surface" ligand-centred reductions around -0.70 V and -1.30 V. Electrospray ionisation mass spectrometry (ESI-MS) and collision induced decomposition (CID) measurements were used to investigate the stability of the new complexes. Thereby, the stability agreed well with the order of the Ir-N-N boolean AND N bond lengths.}, language = {en} } @article{DelahayeGoebelLoebbickeetal.2012, author = {Delahaye, Emilie and Goebel, Ronald and Loebbicke, Ruben and Guillot, Regis and Sieber, Christoph and Taubert, Andreas}, title = {Silica ionogels for proton transport}, series = {Journal of materials chemistry}, volume = {22}, journal = {Journal of materials chemistry}, number = {33}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {0959-9428}, doi = {10.1039/c2jm00037g}, pages = {17140 -- 17146}, year = {2012}, abstract = {A number of ionogels - silica-ionic liquid (IL) hybrid materials - were synthesized and studied for their ionic conductivity. The materials are based on a sulfonated IL, 1-methyl-3-(3-sulfopropyl-)-imidazolium p-toluenesulfonate, [PmimSO(3)H][PTS], which contains a sulfonic acid/sulfonate group both in the IL anion and in the side chain of the IL cation. By way of the sulfonate-sulfonic acid proton transfer, the IL imparts the ionogel with a high ionic conductivity of ca. 10(-2) S cm(-1) in the as-synthesized state at 120 degrees C and 10(-3) S cm(-1) in the dry state at 120 degrees C. The ionogels are stable up to ca. 150 degrees C in dynamic thermogravimetric analysis. This suggests that these materials, which are relatively cheap and easily fabricated, could find application in fuel cells in intermediate temperature ranges where many other membrane materials are not suitable.}, language = {en} } @article{WulfBookhagenScherler2012, author = {Wulf, Hendrik and Bookhagen, Bodo and Scherler, Dirk}, title = {Climatic and geologic controls on suspended sediment flux in the Sutlej River Valley, western Himalaya}, series = {Hydrology and earth system sciences : HESS}, volume = {16}, journal = {Hydrology and earth system sciences : HESS}, number = {7}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1027-5606}, doi = {10.5194/hess-16-2193-2012}, pages = {2193 -- 2217}, year = {2012}, abstract = {The sediment flux through Himalayan rivers directly impacts water quality and is important for sustaining agriculture as well as maintaining drinking-water and hydropower generation. Despite the recent increase in demand for these resources, little is known about the triggers and sources of extreme sediment flux events, which lower water quality and account for extensive hydropower reservoir filling and turbine abrasion. Here, we present a comprehensive analysis of the spatiotemporal trends in suspended sediment flux based on daily data during the past decade (2001-2009) from four sites along the Sutlej River and from four of its main tributaries. In conjunction with satellite data depicting rainfall and snow cover, air temperature and earthquake records, and field observations, we infer climatic and geologic controls of peak suspended sediment concentration (SSC) events. Our study identifies three key findings: First, peak SSC events (a parts per thousand yen 99th SSC percentile) coincide frequently (57-80\%) with heavy rainstorms and account for about 30\% of the suspended sediment flux in the semi-arid to arid interior of the orogen. Second, we observe an increase of suspended sediment flux from the Tibetan Plateau to the Himalayan Front at mean annual timescales. This sediment-flux gradient suggests that averaged, modern erosion in the western Himalaya is most pronounced at frontal regions, which are characterized by high monsoonal rainfall and thick soil cover. Third, in seven of eight catchments, we find an anticlockwise hysteresis loop of annual sediment flux variations with respect to river discharge, which appears to be related to enhanced glacial sediment evacuation during late summer. Our analysis emphasizes the importance of unconsolidated sediments in the high-elevation sector that can easily be mobilized by hydrometeorological events and higher glacial-meltwater contributions. In future climate change scenarios, including continuous glacial retreat and more frequent monsoonal rainstorms across the Himalaya, we expect an increase in peak SSC events, which will decrease the water quality and impact hydropower generation.}, language = {en} } @article{BangHoviSprinz2012, author = {Bang, Guri and Hovi, Jon and Sprinz, Detlef F.}, title = {US presidents and the failure to ratify multilateral environmental agreements}, series = {Climate policy}, volume = {12}, journal = {Climate policy}, number = {6}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1469-3062}, doi = {10.1080/14693062.2012.699788}, pages = {755 -- 763}, year = {2012}, abstract = {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.}, language = {en} } @article{BluethgenDormannPratietal.2012, author = {Bl{\"u}thgen, Nico and Dormann, Carsten F. and Prati, Daniel and Klaus, Valentin H. and Kleinebecker, Till and Hoelzel, Norbert and Alt, Fabian and Boch, Steffen and Gockel, Sonja and Hemp, Andreas and M{\"u}ller, J{\"o}rg and Nieschulze, Jens and Renner, Swen C. and Sch{\"o}ning, Ingo and Schumacher, Uta and Socher, Stephanie A. and Wells, Konstans and Birkhofer, Klaus and Buscot, Francois and Oelmann, Yvonne and Rothenw{\"o}hrer, Christoph and Scherber, Christoph and Tscharntke, Teja and Weiner, Christiane N. and Fischer, Markus and Kalko, Elisabeth K. V. and Linsenmair, Karl Eduard and Schulze, Ernst-Detlef and Weisser, Wolfgang W.}, title = {A quantitative index of land-use intensity in grasslands integrating mowing, grazing and fertilization}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {13}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, number = {3}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2012.04.001}, pages = {207 -- 220}, year = {2012}, abstract = {Land use is increasingly recognized as a major driver of biodiversity and ecosystem functioning in many current research projects. In grasslands, land use is often classified by categorical descriptors such as pastures versus meadows or fertilized versus unfertilized sites. However, to account for the quantitative variation of multiple land-use types in heterogeneous landscapes, a quantitative, continuous index of land-use intensity (LUI) is desirable. Here we define such a compound, additive LUI index for managed grasslands including meadows and pastures. The LUI index summarizes the standardized intensity of three components of land use, namely fertilization, mowing, and livestock grazing at each site. We examined the performance of the LUI index to predict selected response variables on up to 150 grassland sites in the Biodiversity Exploratories in three regions in Germany(Alb, Hainich, Schorlheide). We tested the average Ellenberg nitrogen indicator values of the plant community, nitrogen and phosphorus concentration in the aboveground plant biomass, plant-available phosphorus concentration in the top soil, and soil C/N ratio, and the first principle component of these five response variables. The LUI index significantly predicted the principal component of all five response variables, as well as some of the individual responses. Moreover, vascular plant diversity decreased significantly with LUI in two regions (Alb and Hainich). Inter-annual changes in management practice were pronounced from 2006 to 2008, particularly due to variation in grazing intensity. This rendered the selection of the appropriate reference year(s) an important decision for analyses of land-use effects, whereas details in the standardization of the index were of minor importance. We also tested several alternative calculations of a LUI index, but all are strongly linearly correlated to the proposed index. The proposed LUI index reduces the complexity of agricultural practices to a single dimension and may serve as a baseline to test how different groups of organisms and processes respond to land use. In combination with more detailed analyses, this index may help to unravel whether and how land-use intensities, associated disturbance levels or other local or regional influences drive ecological processes.}, language = {en} }