TY - JOUR A1 - Scheffler, Christiane A1 - Voigt, Andrea T1 - Vergleich statischer und dynamischer Körpermaße von Jüngeren (20 - 29 Jahre) und Älteren (50 - 85 Jahre) Y1 - 2008 SN - 978-3-88383-734-2 ER - TY - JOUR A1 - Scheffler, Ingo T1 - Zur Fähigkeit von Ektoparasiten der Fledermäuse ihre Wirte aktiv aufzusuchen N2 - Active host-searching in bat ectoparasites. As a pilot study, this paper discribes the mobility of ectoparasites after removing from their hosts. Spinturnix acuminatus (Koch, 1836)(Acari, Spinturnicidae) a permanent stationary bat mite normally survives the removing only a few hours. This species moves easily on the patagium or on human skin. In contrast, on other surfaces the movements of this species seems to be less orientated and it is unlikely that the mite can reach a host in some distance. Nycteribia kolenatii Theodor & Moscona, 1954 (Diptera: Nycteribiidae) a bat fly, shows excellent movements in the fur of its host. The specimens survive the removing from the host several days. The ability to clamber up a wall was tested with a rough clay brick. The bat fly achieves only 9,6 cm on average. This result does not support good abilities for host searching in this species. Bat fleas (Siphonaptera: Ischnopsyllidae): Ischnopsyllus elongatus (Curtis, 1832), I. hexactenus (Kolenati, 1856), I. simplex (Rothschild, 1906)and other species survive the removing from their hosts several days. In case of a vertical barrier they showed a stereotype upside climbing, followed by a horizontal appetitive behavior. The fleas were climbing a distance in the upside of 6,45 m on average(1,2-21,68 m). As excellent climbers bat fleas are able to overcome edges and slopes and to crawl on the ceiling. Therefore, it seems to be no problem for a flea to parasite any bat in a resting room. Additionally, some bugs (Cimex lectularius Linnaeus, 1758) were examinated. They run with a speed of 63 cm per minute and were able to climb easily on the brick. On average their stretch of way achieved 2,85 m in ten minutes. Y1 - 2008 ER - TY - JOUR A1 - Köchy, Martin A1 - Mathaj, Martin A1 - Jeltsch, Florian A1 - Malkinson, Dan T1 - Resilience of stocking capacity to changing climate in arid to Mediterranean landscapes N2 - Small livestock is an important resource for rural human populations in dry climates. How strongly will climate change affect the capacity of the rangeland? We used hierarchical modelling to scale quantitatively the growth of shrubs and annual plants, the main food of sheep and goats, to the landscape extent in the eastern Mediterranean region. Without grazing, productivity increased in a sigmoid way with mean annual precipitation. Grazing reduced productivity more strongly the drier the landscape. At a point just under the stocking capacity of the vegetation, productivity declined precipitously with more intense grazing due to a lack of seed production of annuals. We repeated simulations with precipitation patterns projected by two contrasting IPCC scenarios. Compared to results based on historic patterns, productivity and stocking capacity did not differ in most cases. Thus, grazing intensity remains the stronger impact on landscape productivity in this dry region even in the future. Y1 - 2008 UR - http://www.springerlink.com/content/gj0567116q770036/ U6 - https://doi.org/10.1007/s10113-008-0048-6 ER - TY - JOUR A1 - Behrsing, Olaf A1 - Micheel, Burkhard T1 - Monoklonale Antikörper : Grundlagen und ihre Bedeutung in Diagnostik und Therapie Y1 - 2008 SN - 978-3-540-69412-0 ER - TY - JOUR A1 - Koechy, Martin A1 - Brakenhielm, Sven T1 - Separation of effects of moderate N deposition from natural change in ground vegetation of forests and bogs N2 - The effect of moderate rates of nitrogen deposition on ground floor vegetation is poorly predicted by uncontrolled surveys or fertilization experiments using high rates of nitrogen (N) addition. We compared the temporal trends of ground floor vegetation in permanent plots with moderate (7-13 kg/ha/yr) and lower bulk N deposition (4-6 kg/ha/yr) in southern Sweden during 1982-1998. We examined whether trends differed between growth forms (vascular plants and bryophytes) and vegetation types (three types of coniferous forest, deciduous forest, and bog). Trends of site-standardized cover and richness varied among growth forms, vegetation types, and deposition regions. Cover in spruce forests decreased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs cover decreased faster with low deposition. Cover of bryophytes in spruce forests increased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs and deciduous forests there was a strong non-linear increase with moderate deposition. The trend of number of vascular plants was constant with moderate and decreased with low deposition. We found no trend in the number of bryophyte species. We propose that the decrease of cover and number with low deposition was related to normal ecosystem development (increased shading), suggesting that N deposition maintained or increased the competitiveness of some species in the moderate-deposition region. Deposition had no consistent negative effect on vegetation suggesting that it is less important than normal successional processes. Y1 - 2008 UR - http://dx.doi.org/10.1016/j.foreco.2007.11.039 U6 - https://doi.org/10.1016/j.foreco.2007.11.039 ER - TY - JOUR A1 - Köchy, Martin T1 - Effects of simulated daily precipitation patterns on annual plant populations depend on life stage and climatic region N2 - Background To improve the understanding of consequences of climate change for annual plant communities, I used a detailed, grid-based model that simulates the effect of daily rainfall variability on individual plants in five climatic regions on a gradient from 100 to 800 mm mean annual precipitation (MAP). The model explicitly considers moisture storage in the soil. I manipulated daily rainfall variability by changing the daily mean rain (DMR, rain volume on rainy days averaged across years for each day of the year) by ± 20%. At the same time I adjusted intervals appropriately between rainy days for keeping the mean annual volume constant. In factorial combination with changing DMR I also changed MAP by ± 20%. Results Increasing MAP generally increased water availability, establishment, and peak shoot biomass. Increasing DMR increased the time that water was continuously available to plants in the upper 15 to 30 cm of the soil (longest wet period, LWP). The effect of DMR diminished with increasing humidity of the climate. An interaction between water availability and density-dependent germination increased the establishment of seedlings in the arid region, but in the more humid regions the establishment of seedlings decreased with increasing DMR. As plants matured, competition among individuals and their productivity increased, but the size of these effects decreased with the humidity of the regions. Therefore, peak shoot biomass generally increased with increasing DMR but the effect size diminished from the semiarid to the mesic Mediterranean region. Increasing DMR reduced via LWP the annual variability of biomass in the semiarid and dry Mediterranean regions. Conclusion More rainstorms (greater DMR) increased the recharge of soil water reservoirs in more arid sites with consequences for germination, establishment, productivity, and population persistence. The order of magnitudes of DMR and MAP overlapped partially so that their combined effect is important for projections of climate change effects on annual vegetation. Y1 - 2008 UR - http://www.biomedcentral.com/1472-6785/8/4 ER - TY - JOUR A1 - Thiele, T. A1 - Jeltsch, Florian A1 - Blaum, Niels T1 - Importance of woody vegetation for foraging site selection in the Southern Pied Babbler (Turdoides bicolor) under two different land use regimes Y1 - 2008 SN - 0140-1963 ER - TY - JOUR A1 - Pagel, Jörn A1 - Fritzsch, Katrin A1 - Biedermann, Robert A1 - Schröder-Esselbach, Boris T1 - Annual plants under cyclic disturbance regime : better understanding through model aggregation N2 - In their application for conservation ecology, 'classical' analytical models and individual-based simulation models (IBMs) both entail their specific strengths and weaknesses, either in providing a detailed and realistic representation of processes or in regard to a comprehensive model analysis. This well-known dilemma may be resolved by the combination of both approaches when tackling certain problems of conservation ecology. Following this idea, we present the complementary use of both an IBM and a matrix population model in a case study on grassland conservation management. First, we develop a spatially explicit IBM to simulate the long-term response of the annual plant Thlaspi perfoliatum (Brassicaceae), claspleaf pennycress, to different management schemes (annual mowing vs. infrequent rototilling) based on field experiments. In order to complement the simulation results by further analyses, we aggregate the IBM to a spatially nonexplicit deterministic matrix population model. Within the periodic environment created by management regimes, population dynamics are described by periodic products of annual transition matrices. Such periodic matrix products provide a very conclusive framework to study the responses of species to different management return intervals. Thus, using tools of matrix model analysis (e.g., loop analysis), we can both identify dormancy within the age-structured seed bank as the pivotal strategy for persistence under cyclic disturbance regimes and reveal crucial thresholds in some less certain parameters. Results of matrix model analyses are therefore successfully tested by comparing their results to the respective IBM simulations. Their implications for an enhanced scientific basis for management decisions are discussed as well as some general benefits and limitations of the use of aggregating modeling approaches in conservation. Y1 - 2008 UR - 1960 = DOI: 10.1890/07-1305.1 SN - 1051-0761 ER - TY - JOUR A1 - Schiffers, Katja A1 - Schurr, Frank Martin A1 - Tielbörger, Katja A1 - Urbach, Carsten A1 - Moloney, Kirk A. A1 - Jeltsch, Florian T1 - Dealing with virtual aggregation : a new index for analysing heterogeneous point patterns Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/117966123/home U6 - https://doi.org/10.1111/j.0906-7590.2008.05374.x SN - 0906-7590 ER - TY - JOUR A1 - Higgins, Steven I. A1 - Flores, Olivier A1 - Schurr, Frank Martin T1 - Costs of persistence and the spread of competing seeders and sprouters Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/118509661/home U6 - https://doi.org/10.1111/j.1365-2745.2008.01391.x SN - 0022-0477 ER - TY - JOUR A1 - Berger, Dieter A1 - Walters, R. J. A1 - Gotthard, K. T1 - What limits insect fecundity? : Body size- and temperature-dependent egg maturation and oviposition in a butterfly N2 - * 1. Large female insects usually have high potential fecundity. Therefore selection should favour an increase in body size given that these females get opportunities to realize their potential advantage by maturing and laying more eggs. However, ectotherm physiology is strongly temperature-dependent, and activities are carried out sufficiently only within certain temperature ranges. Thus it remains unclear if the fecundity advantage of a large size is fully realized in natural environments, where thermal conditions are limiting. * 2. Insect fecundity might be limited by temperature at two levels; first eggs need to mature, and then the female needs time for strategic ovipositing of the egg. Since a female cannot foresee the number of oviposition opportunities that she will encounter on a given day, the optimal rate of egg maturation will be governed by trade-offs associated with egg- and time-limited oviposition. As females of different sizes will have different amounts of body reserves, size-dependent allocation trade-offs between the mother"s condition and her egg production might be expected. * 3. In the temperate butterfly Pararge aegeria, the time and temperature dependence of oviposition and egg maturation, and the interrelatedness of these two processes were investigated in a series of laboratory experiments, allowing a decoupling of the time budgets for the respective processes. * 4. The results show that realized fecundity of this species can be limited by both the temperature dependence of egg maturation and oviposition under certain thermal regimes. Furthermore, rates of oviposition and egg maturation seemed to have regulatory effects upon each other. Early reproductive output was correlated with short life span, indicating a cost of reproduction. Finally, large females matured more eggs than small females when deprived of oviposition opportunities. Thus, the optimal allocation of resources to egg production seems dependent on female size. * 5. This study highlights the complexity of processes underlying rates of egg maturation and oviposition in ectotherms under natural conditions. We further discuss the importance of temperature variation for egg- vs. time-limited fecundity and the consequences for the evolution of female body size in insects. Y1 - 2008 UR - http://dx.doi.org/10.1111/j.1365-2435.2008.01392.x U6 - https://doi.org/10.1111/j.1365-2435.2008.01392.x SN - 0269-8463 ER - TY - JOUR A1 - Schmidt, Martin A1 - Kaspar, Rüdiger A1 - Richter, Torsten ED - Kummer, Volker T1 - Ergebnisse der Tagung des BFA Mykologie (NABU) 2006 in Linowsee bei Rheinsberg/Brandenburg Y1 - 2008 ER - TY - JOUR A1 - Küster, Frank A1 - Seckler, Robert T1 - Pea seed lectin folds and oligomerizes via an intermediate not represented in the structural hierarchy N2 - Large oligomeric proteins are usually thought to fold and assemble hierarchically: Domains fold and coalesce to form the subunits, and folded subunits can then associate to form the multimeric structure. We have investigated the refolding pathway of the ;-sheet protein pea seed lectin using spectroscopic and hydrodynamic techniques. In vivo, it is proteolytically processed post-translationally, so that the single-domain subunits of the initial homodimer themselves become heterodimers of intertwined fragment polypeptide chains. Despite this complex topology, mature pea seed lectin reassembles with considerable efficiency at low total protein concentration (10 ;g/mL) and low temperature (10 °C), albeit very slowly (t1/2 ; 2 days). Contrary to expectations, the primary assembly product is not the intact ;-sheet domain, but the larger fragment chains first dimerize to form the native-like subunit interface. The smaller fragment chains then associate with this preformed dimer. Y1 - 2008 UR - http://pubs.acs.org/doi/abs/10.1021/bi7019047 U6 - https://doi.org/10.1021/Bi7019047 SN - 0006-2960 ER - TY - JOUR A1 - Blaum, Niels A1 - Engeman, Richard M. A1 - Wasiolka, Bernd A1 - Rossmanith, Eva T1 - Indexing small mammalian carnivores in the southern Kalahari, South Africa N2 - Monitoring animal populations in changing environments is crucial to wildlife conservation and management, but restrictions in resources are a recurring problem for wildlife managers and researchers throughout Africa. Land-use- induced shrub encroachment in Kalahari savannah rangelands has led to fragmentation of the landscape. Mammalian carnivores are particularly vulnerable to local extinction in fragmented landscapes, but their low numbers and their often nocturnal and secretive habits make them difficult to monitor. In this study, we tested the applicability of a passive tracking method and compared two measurement methods and index calculations for monitoring small carnivores across a grazing gradient in the southern Kalahari. During the four years of monitoring in a five-year period, we used the knowledge of indigenous Khoisan Bushmen for the identification of carnivore tracks on 640 sand transects (5 m x 250 m). Our results showed that this simple and inexpensive observation method enabled detailed monitoring of 10 small carnivore species across the grazing gradient. A binary index calculated an index based on presence/absence of a species' tracks on each transect, whereas the track intrusion index used the number of track intrusions to each transect for each species in its calculations. For less common species, the two indices were similar in trend and magnitude, because the number of intrusions to each transect was typically 1 or 0. Usually, the two indices showed relatively strong correlations. However, species with patchy distributions of higher numbers presented difficulties for the binary index to monitor trends, but not for the track intrusion index. Y1 - 2008 SN - 1035-3712 ER - TY - JOUR A1 - Kummer, Volker T1 - Beiträge zur Pilzflora der Luckauer Umgebung : die Ergebnisse der Pilzexkursion am 07.10.07 in der Calauer Schweiz bei Cabel Y1 - 2008 ER - TY - JOUR A1 - Kummer, Volker T1 - Bemerkenswerte Pflanzenarten des Spreewaldes : 2. Moorflanzen ; Teil 2 Y1 - 2008 ER - TY - JOUR A1 - Scheffler, Ingo T1 - Untersuchungen zur Ektoparasitenfauna (Siphonaptera: Ischnopsyllidae; Diptera: Nycteribiidae; Heteroptera: Cimicidae) an Fledermäusen : Teil 3 N2 - Die vorliegende Untersuchung von Fledermaeusen in Sommer- und Winterquartieren liefert neue daten zur Verbreitung und Haeufigkeit von Ektoparasiten aus Brandenburg und anderen Bundeslaendern. An 11 Fledermausarten wurden insgesamt 7 Floharten (Ischnosyllidae), zwei Lausfliegenarten (Nycteribiidae) und zwei Wanzenarten (Cimicidae) nachgewiesen. Die Floharten Ischnopsyllus intermedius und die Artengruppe I. simplex/mysticus ergaenzen die Liste der aktuellen Funde fuer Brandenburg. Nach dem milden Winter 2006-7 wurden in einigen Winterquartieren Veraenderungen im Artenspektrum der Parasiten festgestellt. Nycteribia kolenatii an Myotis daubentoni und Nycteribia eusarca an Nyctalus noctula traten bei der vorliegenden Untersuchung relativ haeufig auf. Die anderen ektoparasitischen Floehe und Lausfliegen waren sehr selten zu finden. Die meisten Parasitenarten und die hoechste Befallsintensitaet wies die Wasserfledermaus (Myotis daubentoni) auf. Y1 - 2008 ER - TY - JOUR A1 - Schurr, Frank Martin A1 - Steinitz, Ofer A1 - Nathan, Ran T1 - Plant fecundity and seed dispersal in spatially heterogeneous environments : models, mechanisms and estimation Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/118509661/home U6 - https://doi.org/10.1111/j.1365-2745.2008.01371.x SN - 0022-0477 ER - TY - JOUR A1 - Kane, Avinash S. A1 - Hoffmann, Armin S. A1 - Baumgärtel, Peter A1 - Seckler, Robert A1 - Reichardt, Gerd A1 - Horsley, David A. A1 - Schuler, Benjamin A1 - Bakajin, Olgica T1 - Microfluidic mixers for the investigation of rapid protein folding kinetics using synchrotron radiation circular dichroism spectroscopy N2 - We have developed a microfluidic mixer optimized for rapid measurements of protein folding kinetics using synchrotron radiation circular dichroism (SRCD) spectroscopy. The combination of fabrication in fused silica and synchrotron radiation allows measurements at wavelengths below 220 nm, the typical limit of commercial instrumentation. At these wavelengths, the discrimination between the different types of protein secondary structure increases sharply. The device was optimized for rapid mixing at moderate sample consumption by employing a serpentine channel design, resulting in a dead time of less than 200 ;s. Here, we discuss the design and fabrication of the mixer and quantify the mixing efficiency using wide-field and confocal epi-fluorescence microscopy. We demonstrate the performance of the device in SRCD measurements of the folding kinetics of cytochrome c, a small, fast-folding protein. Our results show that the combination of SRCD with microfluidic mixing opens new possibilities for investigating rapid conformational changes in biological macromolecules that have previously been inaccessible. Y1 - 2008 UR - http://pubs.acs.org/doi/abs/10.1021/ac801764r SN - 0003-2700 ER - TY - JOUR A1 - Barbirz, Stefanie A1 - Müller, Jürgen J. A1 - Uetrecht, Charlotte A1 - Clark, Alvin J. A1 - Heinemann, Udo A1 - Seckler, Robert T1 - Crystal structure of Escherichia coli phage HK620 tailspike : podoviral tailspike endoglycosidase modules are evolutionarily related N2 - Bacteriophage HK620 infects Escherichia coli H and is closely related to Shigella phage Sf6 and Salmonella phage P22. All three Podoviridae recognize and cleave their respective host cell receptor polysaccharide by homotrimeric tailspike proteins. The three proteins exhibit high sequence identity in the 110 residues of their N-terminal particle- binding domains, but no apparent sequence similarity in their major, receptor-binding parts. We have biochemically characterized the receptor-binding part of HK620 tailspike and determined its crystal structure to 1.38 Å resolution. Its major domain is a right-handed parallel ;-helix, as in Sf6 and P22 tailspikes. HK620 tailspike has endo-N- acetylglucosaminidase activity and produces hexasaccharides of an O18A1-type O-antigen. As indicated by the structure of a hexasaccharide complex determined at 1.6 Å resolution, the endoglycosidase-active sites are located intramolecularly, as in P22, and not between subunits, as in Sf6 tailspike. In contrast, the extreme C-terminal domain of HK620 tailspike forms a ;-sandwich, as in Sf6 and unlike P22 tailspike. Despite the different folds, structure-based sequence alignments of the C-termini reveal motifs conserved between the three proteins. We propose that the tailspike genes of P22, Sf6 and HK620 have a common precursor and are not mosaics of unrelated gene fragments. Y1 - 2008 UR - http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2958.2008.06311.x/pdf SN - 0950-382X ER - TY - JOUR A1 - Fabian, Heinz A1 - Gast, Klaus A1 - Laue, Michael A1 - Misselwitz, Rolf A1 - Uchanska-Ziegler, Barbara A1 - Ziegler, Andreas A1 - Naumann, Dieter T1 - Early stages of misfolding and association of beta2-microglobulin : insights from infrared spectroscopy and dynamic light scattering N2 - Conformational changes associated with the assembly of recombinant ;2-microglobulin in vitro under acidic conditions were investigated using infrared spectroscopy and static and dynamic light scattering. In parallel, the morphology of the different aggregated species obtained under defined conditions was characterized by electron microscopy. The initial salt-induced aggregate form of ;2-microglobulin, composed of small oligomers (dimers to tetramers), revealed the presence of ;-strands organized in an intramolecular-like fashion. Further particle growth was accompanied by the formation of intermolecular ;-sheet structure and led to short curved forms. An increase in temperature by only 25 °C was able to disaggregate these assemblies, followed by the formation of longer filamentous structures. In contrast, a rise in temperature up to 100 °C was associated with a reorganization of the short curved forms at the level of secondary structure and the state of assembly, leading to a species with a characteristic infrared spectrum different from those of all the other aggregates observed before, suggesting a unique overall structure. The infrared spectral features of this species were nearly identical to those of ;2-microglobulin assemblies formed at low ionic strength with agitation, indicating the presence of fibrils, which was confirmed by electron microscopy. The observed spectroscopic changes suggest that the heat-triggered conversion of the short curved assemblies into fibrils involves a reorganization of the ;-strands from an antiparallel arrangement to a parallel arrangement, with the latter being characteristic of amyloid fibrils of ;2-microglobulin. Y1 - 2008 UR - http://pubs.acs.org/doi/abs/10.1021/bi800279y ER - TY - JOUR A1 - Müller, Jürgen J. A1 - Barbirz, Stefanie A1 - Heinle, Karolin A1 - Freiberg, Alexander A1 - Seckler, Robert A1 - Heinemann, Udo T1 - An intersubunit active site between supercoiled parallel beta helices in the trimeric tailspike endorhamnosidase of Shigella flexneri phage Sf6 N2 - Sf6 belongs to the Podoviridae family of temperate bacteriophages that infect gram-negative bacteria by insertion of their double-stranded DNA. They attach to their hosts specifically via their tailspike proteins. The 1.25 Å crystal structure of Shigella phage Sf6 tailspike protein (Sf6 TSP) reveals a conserved architecture with a central, right-handed ; helix. In the trimer of Sf6 TSP, the parallel ; helices form a left-handed, coiled;; coil with a pitch of 340 Å. The C-terminal domain consists of a ; sandwich reminiscent of viral capsid proteins. Further crystallographic and biochemical analyses show a Shigella cell wall O-antigen fragment to bind to an endorhamnosidase active site located between two ;-helix subunits each anchoring one catalytic carboxylate. The functionally and structurally related bacteriophage, P22 TSP, lacks sequence identity with Sf6 TSP and has its active sites on single subunits. Sf6 TSP may serve as an example for the evolution of different host specificities on a similar general architecture. Y1 - 2008 UR - http://www.cell.com/structure/abstract/S0969-2126%2808%2900106-8 U6 - https://doi.org/10.1016/j.str.2008.01.019 ER - TY - JOUR A1 - Walter, Monica A1 - Fiedler, Christian A1 - Grassl, Renate A1 - Biebl, Manfred A1 - Rachel, Reinhard A1 - Hermo-Parrado, Lois X. A1 - Llamas-Saiz, Aantonio L. A1 - Seckler, Robert A1 - Miller, Stefan A1 - Raaij van, Mark J. T1 - Structure of the receptor-binding protein of bacteriophage Det7 : a podoviral tailspike in a myovirus Y1 - 2008 UR - http://jvi.asm.org/cgi/content/abstract/82/5/2265 SN - 0022-538X ER - TY - JOUR A1 - Landström, Jens A1 - Nordmark, Eva-Lisa A1 - Eklund, Robert A1 - Weintraub, Andrej A1 - Seckler, Robert A1 - Widmalm, Göran T1 - Interaction of a Salmonella enteritidis O-antigen octasaccharide with the phage P22 tailspike protein by NMR spectroscopy and docking studies N2 - The tailspike protein P22 recognizes an octasaccharide derived from the O-antigen polysaccharide of Salmonella enteritidis in a shallow groove and molecular docking successfully identifies this binding region on the protein surface. Analysis by 2D 1H,1H-T-ROESY and transferred NOESY NMR experiments indicate that the bound octasaccharide ligand has a conformation similar to that observed in solution. The results from a saturation transfer difference NMR experiment show that a large number of protons in the octasaccharide are in close contact with the protein as a result of binding. A comparison of the crystal structure of the complex and a molecular dynamics simulation of the octasaccharide with explicit water molecules suggest that only minor conformational changes are needed upon binding to the tailspike protein. Y1 - 2008 UR - http://www.springerlink.com/content/w3146138p25r2456/ U6 - https://doi.org/10.1007/s10719-007-9065-9 SN - 0282-0080 ER - TY - JOUR A1 - Koch, Jennifer A1 - Schaldach, Rüdiger A1 - Koechy, Martin T1 - Modeling the impacts of grazing land management on land-use change for the Jordan River region N2 - In this article, we describe a simulation method for investigating the impacts of different grazing land management strategies on the productivity of (semi-)natural vegetation and the resulting feedback on land-use change. In a first application, we analyze the effects of sustainable and intensive grazing land management in the Jordan River region. For this purpose, we adapt and use the regional version of the spatially explicit modeling framework LandSHIFT. Our simulation experiments indicate that the modeled feedback mechanism has a strong effect on the spatial extent of grazing land. Consequently, the results of our study underline that the inclusion of such feedback mechanisms in land- use models can help to represent and analyze the complex interactions between humans and the environment in a more differentiated and realistic way, but they also identify the demand for more detailed empirical data on grazing land degradation in order to further improve the explanatory power of the model. Y1 - 2008 UR - http://www.sciencedirect.com/science/article/B6VF0-4TPX0NJ-5/2/ 34ae74c07f60d91307937896c0378ddf U6 - https://doi.org/10.1016/j.gloplacha.2008.09.005 ER - TY - JOUR A1 - Scheffler, Christiane A1 - Voigt, Andrea ED - Bodzsár, Eva ED - Susanne, Charles T1 - Physical Mobility of the Elderly - Anthropometric Data of Static and Dynamic Measurements, and Physiologic Parameters under Stress Conditions Y1 - 2008 SN - 978-963-06-5222-3 ER - TY - JOUR A1 - Knösche, Rüdiger T1 - Wiederfund von Najas marina L. ssp. marina im Schollener See (Elbe-Havel-Winkel, Sachsen-Anhalt) Y1 - 2008 SN - 1432-8038 ER - TY - JOUR A1 - Berger, Uta A1 - Piou, Cyril A1 - Schiffers, Katja A1 - Grimm, Volker T1 - Competition among plants : concepts, individual-based modelling approaches, and a proposal for a future research strategy N2 - Competition is a key process in plant populations and communities. We thus need, if we are to predict the responses of ecological systems to environmental change, a comprehensive and mechanistic understanding of plant competition. Considering competition, however, only at the population level is not sufficient because plant individuals usually are different, interact locally, and can adapt their behaviour to the current state of themselves and of their biotic and abiotic environment. Therefore, simulation models that are individual-based and spatially explicit are increasingly used for studying competition in plant systems. Many different individual-based modelling approaches exist to represent competition, but it is not clear how good they are in reflecting essential aspects of plant competition. We therefore first summarize current concepts and theories addressing plant competition. Then, we review individual-based approaches for modelling competition among plants. We distinguish between approaches that are used for more than 10 years and more recent ones. We identify three major gaps that need to be addressed more in the future: the effects of plants on their local environment, adaptive behaviour, and below-ground competition. To fill these gaps, the representation of plants and their interactions have to be more mechanistic than most existing approaches. Developing such new approaches is a challenge because they are likely to be more complex and to require more detailed knowledge and data on individual-level processes underlying competition. We thus need a more integrated research strategy for the future, where empirical and theoretical ecologists as well as computer scientists work together on formulating, implementing, parameterization, testing, comparing, and selecting the new approaches. (c) 2008 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved. Y1 - 2008 SN - 1433-8319 ER - TY - JOUR A1 - Bitzer, Jens A1 - Laessøe, Thomas A1 - Fournier, Jaques A1 - Kummer, Volker A1 - Decock, Cony A1 - Tichy, Hans-Volker A1 - Piepenbring, Meike A1 - Persoh, Derek A1 - Stadler, Marc T1 - Affinities of Phylacia and the daldinioid Xylariaceae, inferred from chemotypes of cultures and ribosomal DNA sequences N2 - A chemotaxonomic evaluation using hplc profiling was undertaken to resolve the infrageneric and intergeneric affinities of over 150 strains of Xylariaceae. Daldinia placentiformis, Hypoxylon nicaraguense, H. polyporus, and Phylacia sagrana were found to contain 8-methoxy-1-naphthol, which is apparently absent in Annulohypoxylon, Hypoxylon, and related genera with bipartite stromata. D. placentiformis and other species of Daldinia and Entonaema produced this naphthol, 5-hydroxy-2-methylchromone, isosclerone derivatives, and 'AB-5046' phytotoxins. Phylacia sagrana differed from most Daldinia spp., except for D. caldariorum, by producing eutypine derivatives in addition to the above compounds. indolylquinones were observed in H. nicaraguense and H. polyporus. Isosclerones were also identified in the A. multiforme complex, but Hypoxylon and other Annulohypoxylon and most Hypoxylon spp. studied Annulohypoxylon spp. contained S-methylmellein as the major metabolite of their cultures. Based on the occurrence of the above metabolites, further mellein-type dihydroisocoumarins, teleomorphic and anamorphic Xylariaceae with Nodulisporium-like anamorphs ('Hypoxyloideae') were divided into various chemotypes. A comparison of their 5.8S/ ITS nuc-rDNA sequences agreed in some important aspects with the above results: H. nicaraguense and H. polyporus appeared basal to a clade comprising Daldinia, Entonaema, and Ph. sagrana. The latter species appeared allied to D. caldariorum, but was distantly related to Pyrenomyxa morganii and Hypoxylon s. str. (C) 2007 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. Y1 - 2008 SN - 0953-7562 ER - TY - JOUR A1 - Heinken, Thilo T1 - Vegetation und Standort bodensaurer Buchenwälder am Arealrand : am Beispiel Mittelbrandenburgs N2 - Different from NW Germany, the northern part of NE Germany and the "Hohe Flaeming" region, central Brandenburg is considered as being largely devoid of natural beech forests because of its subcontinental, dry climate. In the present study the vegetation ecology of beech forests of the region is comprehensively documented for the first time, and they are compared with NW German stands in Lower Saxony. In the study area beech forests are concentrated in the Berlin-Potsdam region along the Havel river lakes which is characterised by relatively high precipitation and a specific land use history. All belong to the Luzulo-Fagetum growing on acid soils. Four subtypes are distinguished according to nutrient availability and soil moisture. The central Brandenburg Luzulo-Fagetum does not markedly deviate from other beech forests in the northern German lowlands with respect to vegetation structure and edaphic subtypes. However, numerous indicator species for humid or moist conditions are less frequent than under atlantic climate conditions in the lowlands of Lower Saxony, a pattern occurring also in other forest communities. On the other hand, nitrogen and disturbance indicators are more frequent in central Brandenburg. As expected, podzolisation of the soils and humus accumulation is lower in beech forests under subcontinental climate, but surprisingly the soils are more sandy and thus drier. However, beech forests are lacking on south-exposed slopes, and they are notably occurring in northern exposition. A combined analysis of distribution patterns and climatic data, postglacial vegetation history and forest use history, and actual rejuvenation dynamics reveals that the present-day beech forests in central Brandenburg have to be considered as near-natural relics, which are currently spreading. The range of potentially natural beech forests is larger than assumed until now, but further on it is not clearly to define. Y1 - 2008 SN - 0018-0637 ER - TY - JOUR A1 - Heinken, Thilo T1 - Welche populationsbiologischen und genetischen Konsequenzen hat Habitatfragmentierung für Pflanzen? : Wissenschaftliche Grundlagen für ein Biotopverbundsystem für Pflanzen in Brandenburg N2 - Neben dem Habitatverlust gelten Konsequenzen der Habitatfragmentierung seit den 1990er Jahren als wesentliche Ursache der Gefaehrdung von Pflanzen und stehen damit nun auch im Fokus des botanischen Artenschutzes. Der vorliegende Beitrag gibt einen ueberblick ueber den Stand der populationsbiologischen und genetischen Forschung und versucht abzuschaetzen, welche Bedeutung Habitatfragmentierung und die dadurch entstehenden kleinen, isolierten Populationen auf heimische Pflanzenarten haben koennen. Als wesentliche und offenbar sehr weit verbreitete negative Effekte werden Zufallsereignisse, Randeffekte, Bestaeuberlimitierung, Gendrift und Inzuchtdepression identifiziert. Zusammen mit verringerter Habitatqualitaet durch Eutrophierung, Entwaesserung oder Nutzungsaenderung wirken sie zumeist negativ auf die Fitness der Individuen und Populationen und erhoehen so deren Aussterberisiko. Dieser negative Effekt kleiner Populationen auf die individuelle Fitness wird unabhaengig von der Ursache als Allee-Effekt bezeichnet. Eine durch einen Biotopverbund gefoerderte Metapopulationsdynamik kann das dauerhafte Aussterben von Pflanzenpopulationen verhindern und mindert die negativen genetischen Effekte der Habitatfragmentierung ueber einen erhoehten Genfluss durch Pollen und Samen. Die bisherigen wissenschaftlichen Studien in Mitteleuropa beruhen allerdings in ueberproportionaler Weise auf bestimmten Pflanzenfamilien (Gentianaceae, Primulaceae), Habitaten (Trocken- und Magerrasen, Wirtschaftsgruenland), insekten- und obligat fremdbestaeubten sowie weitgehend auf sexuelle Fortpflanzung angewiesenen Arten, waehrend etwa ueber Grasartige, Ruderalpflanzen, wind- und selbstbestaeubte sowie an vegetative Fortpflanzung angepasste Arten nur wenige Erkenntnisse vorliegen. Gerade diese und Pflanzenarten mit hohem Ausbreitungspotenzial muessen aber nach derzeitigem Wissensstand als weniger sensitiv gegenueber Habitatfragmentierung eingestuft werden. Auf diesen Befunden aufbauend werden fuer die Naturschutzpraxis Biotoptypen hinsichtlich ihrer Sensitivitaet gegenueber Habitatfragmentierung klassifiziert und ein auf biologischen Merkmalen basierender Kriterienkatalog zur Auswahl von Zielarten des Biotopverbunds vorgestellt. Schließlich wird eroertert, was bei Maßnahmen zur Regeneration kleiner bzw. bereits ausgestorbener Populationen zu beachten ist, und es werden allgemeine Folgerungen zur Ausgestaltung eines Biotopverbundskonzepts fuer Pflanzen gezogen. Y1 - 2008 SN - 0942-9328 ER - TY - JOUR A1 - Nathan, Ran A1 - Schurr, Frank Martin A1 - Spiegel, Orr A1 - Steinitz, Ofer A1 - Trakhtenbrot, Ana A1 - Tsoar, Asaf T1 - Mechanisms of long-distance seed dispersal N2 - Growing recognition of the importance of long-distance dispersal (LDD) of plant seeds for various ecological and evolutionary processes has led to an upsurge of research into the mechanisms underlying LDD. We summarize these findings by formulating six generalizations stating that LDD is generally more common in open terrestrial landscapes, and is typically driven by large and migratory animals, extreme meteorological phenomena, ocean currents and human transportation, each transporting a variety of seed morphologies. LDD is often associated with unusual behavior of the standard vector inferred from plant dispersal morphology, or mediated by nonstandard vectors. To advance our understanding of LDD, we advocate a vector-based research approach that identifies the significant LDD vectors and quantifies how environmental conditions modify their actions. Y1 - 2008 UR - http://www.sciencedirect.com/science/journal/01695347 U6 - https://doi.org/10.1016/j.tree.2008.08.003 SN - 0169-5347 ER - TY - JOUR A1 - Voigt, Bernd A1 - Krikunova, Maria A1 - Lokstein, Heiko T1 - Influence of detergent concentration on aggregation and the spectroscopic properties of light-harvesting complex II Y1 - 2008 U6 - https://doi.org/10.1007/s11120-007-9250-5 ER - TY - JOUR A1 - Schwager, Monika A1 - Covas, Rita A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Limitations of population models in predicting climate change effects : a simulation study of sociable weavers in southern Africa Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/118531693/home U6 - https://doi.org/10.1111/j.0030-1299.2008.16464.x SN - 0030-1299 ER - TY - JOUR A1 - Thuiller, Wilfried A1 - Albert, Cécile H. A1 - Araújo, Miguel B. A1 - Berry, Pam M. A1 - Cabeza, Mar A1 - Guisan, Antoine A1 - Hickler, Thomas A1 - Midgley, Guy F. A1 - Paterson, James A1 - Schurr, Frank Martin A1 - Sykes, Martin T. A1 - Zimmermann, Niklaus E. T1 - Predicting global change impacts on plant species' distributions : future challenges Y1 - 2008 U6 - https://doi.org/10.1016/j.ppees.2007.09.004 SN - 1433-8319 ER - TY - JOUR A1 - Körner, Katrin A1 - Jeltsch, Florian T1 - Detecting general plant functional type responses in fragmented landscapes using spatially-explicit simulations Y1 - 2008 UR - http://www.sciencedirect.com/science/journal/03043800 U6 - https://doi.org/10.1016/j.ecolmodel.2007.08.002 SN - 0304-3800 ER - TY - JOUR A1 - Schmidt, Marcus A1 - Fischer, Petra A1 - Günzl, Bettina A1 - Heinken, Thilo A1 - Kelm, Hans-Jürgen A1 - Meyer, Peter A1 - Prüter, Johannes A1 - Waesch, Gunnar T1 - Flechten-Kiefernwälder : Artenvielfalt durch alte Nutzungsformen? Y1 - 2008 SN - 1430-2713 ER - TY - JOUR A1 - Esther, Alexandra A1 - Groeneveld, Jürgen A1 - Enright, Neal J. A1 - Miller, Ben P. A1 - Lamont, Byron B. A1 - Perry, George L. W. A1 - Schurr, Frank Martin A1 - Jeltsch, Florian T1 - Assessing the importance of seed immigration on coexistence of plant functional types in a species-rich ecosystem N2 - Modelling and empirical studies have shown that input from the regional seed pool is essential to maintain local species diversity. However, most of these studies have concentrated on simplified, if not neutral, model systems, and focus on a limited subset of species or on aggregated measures of diversity only (e.g., species richness or Shannon diversity). Thus they ignore more complex species interactions and important differences between species. To gain a better understanding of how seed immigration affects community structure at the local scale in real communities we conducted computer simulation experiments based on plant functional types (PFTs) for a species-rich, fire-prone Mediterranean-type shrubland in Western Australia. We developed a spatially explicit simulation model to explore the community dynamics of 38 PFTs, defined by seven traits - regeneration mode, seed production, seed size, maximum crown diameter, drought tolerance, dispersal mode and seed bank type - representing 78 woody species. Model parameterisation is based on published and unpublished data on the population dynamics of shrub species collected over 18 years. Simulation experiments are based on two contrasting seed immigration scenarios: (1) the 'equal seed input number' scenario, where the number of immigrant seeds is the same for all PFTs, and (2) the 'equal seed input mass' scenario, where the cumulative mass of migrating seeds is the same for all PFTs. Both scenarios were systematically tested and compared for different overall seed input values. Without immigration the local community drifts towards a state with only 13 coexisting PFTs. With increasing immigration rates in terms of overall mass of seeds the simulated number of coexisting PFTs and Shannon diversity quickly approaches values observed in the field. The equal seed mass scenario resulted in a more diverse community than did the seed number scenario. The model successfully approximates the frequency distributions (relative densities) of all individual plant traits except seed size for scenarios associated with equal seed input mass and high immigration rate. However, no scenario satisfactorily approximated the frequency distribution for all traits in combination. Our results show that regional seed input can explain the more aggregated measures of local community structure, and some, but not all, aspects of community composition. This points to the possible importance of other (untested) processes and traits (e.g., dispersal vectors) operating at the local scale. Our modelling framework can readily allow new factors to be systematically investigated, which is a major advantage compared to previous simulation studies, as it allows us to find structurally realistic models, which can address questions pertinent to ecological theory and to conservation management. Y1 - 2008 UR - http://www.sciencedirect.com/science/journal/03043800 U6 - https://doi.org/10.1016/j.ecolmodel.2008.01.014 SN - 0304-3800 ER - TY - JOUR A1 - Blaum, Niels T1 - Seasonal differences in spatial distribution of small carnivores in fragmented savannah landscapes Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/118510939/home U6 - https://doi.org/10.1111/j.1365-2028.2008.00977.x SN - 0141-6707 ER - TY - JOUR A1 - Jeltsch, Florian A1 - Moloney, Kirk A. A1 - Schurr, Frank Martin A1 - Köchy, Martin A1 - Schwager, Monika T1 - The state of plant population modelling in light of environmental change N2 - Plant population modelling has been around since the 1970s, providing a valuable approach to understanding plant ecology from a mechanistic standpoint. It is surprising then that this area of research has not grown in prominence with respect to other approaches employed in modelling plant systems. In this review, we provide an analysis of the development and role of modelling in the field of plant population biology through an exploration of where it has been, where it is now and, in our opinion, where it should be headed. We focus, in particular, on the role plant population modelling could play in ecological forecasting, an urgent need given current rates of regional and global environmental change. We suggest that a critical element limiting the current application of plant population modelling in environmental research is the trade-off between the necessary resolution and detail required to accurately characterize ecological dynamics pitted against the goal of generality, particularly at broad spatial scales. In addition to suggestions how to overcome the current shortcoming of data on the process-level we discuss two emerging strategies that may offer a way to overcome the described limitation: (1) application of a modern approach to spatial scaling from local processes to broader levels of interaction and (2) plant functional-type modelling. Finally we outline what we believe to be needed in developing these approaches towards a 'science of forecasting'. Y1 - 2008 U6 - https://doi.org/10.1016/j.ppees.2007.11.004 SN - 1433-8319 ER - TY - JOUR A1 - Moloney, Kirk A. A1 - Jeltsch, Florian T1 - Space matters : novel developments in plant ecology through spatial modelling Y1 - 2008 U6 - https://doi.org/10.1016/j.ppees.2007.12.002 SN - 1433-8319 ER - TY - JOUR A1 - Meyer, Jork A1 - Raudnitschka, Dorit A1 - Steinhauser, J. A1 - Jeltsch, Florian A1 - Brandl, Roland T1 - Biology and ecology of "Thallomys nigricauda" (Rodentia, Muridae) in the Thornveld savannah of South Africa Y1 - 2008 UR - http://www.sciencedirect.com/science/journal/16165047 U6 - https://doi.org/10.1016/j.mambio.2006.11.002 SN - 1616-5047 ER - TY - JOUR A1 - Kuparinen, Anna A1 - Schurr, Frank Martin T1 - Assessing the risk of gene flow from genetically modified trees carrying mitigation transgenes Y1 - 2008 UR - http://www.springerlink.com/content/103794 U6 - https://doi.org/10.1007/s10530-007-9129-6 SN - 1387-3547 ER - TY - JOUR A1 - Berg, Christian A1 - Bilz, Melanie A1 - Ristow, Michael A1 - Raab, Bernd T1 - Important Plant Areas (IPA) : ein internationales Konzept zum Schutz der Wildpflanzen der Erde Y1 - 2008 ER - TY - JOUR A1 - Sellrie, Frank A1 - Warsinke, Axel A1 - Micheel, Burkhard T1 - Homogeneous indirect fluorescence quenching immunoassay for the determination of low molecular weight substances JF - Analytical & bioanalytical chemistry N2 - This paper describes the principle of a homogeneous indirect fluorescence quenching immunoassay that uses monoclonal antibodies. It is a carrier-free assay system that is performed completely in solution. The assay system was established for the determination of a low molecular weight substance (hapten), the herbicide diuron, used as a model analyte. A fluorescein-monuron conjugate together with a fluorescence-quenching monoclonal anti-fluorescein antibody and an anti-analyte antibody (here an anti-diuron/monuron monoclonal antibody) were used as central components of the assay. The fluorescein-monuron conjugate can be bound either by the anti-fluorescein monoclonal antibody or by the anti-diuron/ monuron monoclonal antibody. Due to steric hindrance, binding of both antibodies to the conjugate was not possible at the same time. By selecting the antibody concentrations appropriately, a dynamic equilibrium can be established that permits the preferential binding of the anti-diuron/monuron antibody to the conjugate, which allows the fluorescein in the conjugate to fluoresce. This equilibrium can be easily altered by adding free analyte (diuron), which competes with the conjugate to bind to the anti-diuron/monuron antibody. A reduction of anti-diuron/monuron antibody binding to the conjugate results in an increase in the binding of the anti-fluorescein antibody, which leads to a decrease in the fluorescence of the conjugate. The fluorescence is therefore a direct indicator of the state of equilibrium of the system and thus also the presence of free unconjugated analyte. The determination of an analyte based on this test principle does not require any washing steps. After the test components are mixed, the dynamic equilibrium is rapidly reached and the results can be obtained in less than 5 min by measuring the fluorescence of the fluorescein. We used this test principle for the determination of diuron, which was demonstrated for concentrations of approximately 5 nM. Y1 - 2008 UR - http://www.springerlink.com/content/n7227875454216v7/ VL - 386 IS - 2 SP - 206 EP - 210 ER - TY - JOUR A1 - Schlag, Peter M. A1 - Osterziel, Karl Joseph A1 - Özcelik, Cemil A1 - Scherneck, Siegfried A1 - Wenzel, Katrin A1 - Daskalow, Katjana A1 - Herse, Florian A1 - Seitz, Susanne A1 - Zacharias, Ute A1 - Schenk, Jörg A. A1 - Schulz, Herbert A1 - Hübner, Norbert A1 - Micheel, Burkhard T1 - The protein phosphatase 1 inhibitor KEPI is down regulated in breast cancer cell lines and tissues and involved in the regulation of the tumour suppressor EGR1 via the MEK-ERK pathway N2 - KEPI is a protein kinase C-potentiated inhibitory protein for type 1 Ser/Thr protein phosphatases. We found no or reduced expression of KEPI in breast cancer cell lines, breast tumors and metastases in comparison to normal breast cell lines and tissues, respectively. KEPI protein expression and ubiquitous localization was detected with a newly generated antibody. Ectopic KEPI expression in MCF7 breast cancer cells induced differential expression of 95 genes, including the up-regulation of the tumor suppressors EGR1 (early growth response 1) and PTEN (phosphatase and tensin homolog), which is regulated by EGR1. We further show that the up-regulation of EGR1 in MCF7/KEPI cells is mediated by MEK-ERK signaling. The inhibition of this pathway by the MEK inhibitor UO126 led to a strong decrease in EGR1 expression in MCF7/KEPI cells. These results reveal a novel role for KEPI in the regulation of the tumor suppressor gene EGR1 via activation of the MEK-ERK MAPK pathway. Y1 - 2008 UR - http://www.atypon-link.com/doi/abs/10.1515/BC.2007.062 ER -