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91.
Eric Allan Wolfgang W. Weisser Markus Fischer Ernst-Detlef Schulze Alexandra Weigelt Christiane Roscher Jussi Baade Romain L. Barnard Holger Beßler Nina Buchmann Anne Ebeling Nico Eisenhauer Christof Engels Alexander J. F. Fergus Gerd Gleixner Marlén Gubsch Stefan Halle Alexandra M. Klein Ilona Kertscher Annely Kuu Markus Lange Xavier Le Roux Sebastian T. Meyer Varvara D. Migunova Alexandru Milcu Pascal A. Niklaus Yvonne Oelmann Esther Pašalić Jana S. Petermann Franck Poly Tanja Rottstock Alexander C. W. Sabais Christoph Scherber Michael Scherer-Lorenzen Stefan Scheu Sibylle Steinbeiss Guido Schwichtenberg Vicky Temperton Teja Tscharntke Winfried Voigt Wolfgang Wilcke Christian Wirth Bernhard Schmid 《Oecologia》2013,173(1):223-237
In order to predict which ecosystem functions are most at risk from biodiversity loss, meta-analyses have generalised results from biodiversity experiments over different sites and ecosystem types. In contrast, comparing the strength of biodiversity effects across a large number of ecosystem processes measured in a single experiment permits more direct comparisons. Here, we present an analysis of 418 separate measures of 38 ecosystem processes. Overall, 45 % of processes were significantly affected by plant species richness, suggesting that, while diversity affects a large number of processes not all respond to biodiversity. We therefore compared the strength of plant diversity effects between different categories of ecosystem processes, grouping processes according to the year of measurement, their biogeochemical cycle, trophic level and compartment (above- or belowground) and according to whether they were measures of biodiversity or other ecosystem processes, biotic or abiotic and static or dynamic. Overall, and for several individual processes, we found that biodiversity effects became stronger over time. Measures of the carbon cycle were also affected more strongly by plant species richness than were the measures associated with the nitrogen cycle. Further, we found greater plant species richness effects on measures of biodiversity than on other processes. The differential effects of plant diversity on the various types of ecosystem processes indicate that future research and political effort should shift from a general debate about whether biodiversity loss impairs ecosystem functions to focussing on the specific functions of interest and ways to preserve them individually or in combination. 相似文献
92.
Ludovic D'Auria Marisa Fenaux Paulina Aleksandrowicz Patrick Van Der Smissen Christophe Chantrain Christiane Vermylen Miikka Vikkula Pierre J. Courtoy Donatienne Tyteca 《Journal of lipid research》2013,54(4):1066-1076
Micrometric membrane lipid segregation is controversial. We addressed this issue in attached erythrocytes and found that fluorescent boron dipyrromethene (BODIPY) analogs of glycosphingolipids (GSLs) [glucosylceramide (BODIPY-GlcCer) and monosialotetrahexosylganglioside (GM1BODIPY)], sphingomyelin (BODIPY-SM), and phosphatidylcholine (BODIPY-PC inserted into the plasma membrane spontaneously gathered into distinct submicrometric domains. GM1BODIPY domains colocalized with endogenous GM1 labeled by cholera toxin. All BODIPY-lipid domains disappeared upon erythrocyte stretching, indicating control by membrane tension. Minor cholesterol depletion suppressed BODIPY-SM and BODIPY-PC but preserved BODIPY-GlcCer domains. Each type of domain exchanged constituents but assumed fixed positions, suggesting self-clustering and anchorage to spectrin. Domains showed differential association with 4.1R versus ankyrin complexes upon antibody patching. BODIPY-lipid domains also responded differentially to uncoupling at 4.1R complexes [protein kinase C (PKC) activation] and ankyrin complexes (in spherocytosis, a membrane fragility disease). These data point to micrometric compartmentation of polar BODIPY-lipids modulated by membrane tension, cholesterol, and differential association to the two nonredundant membrane:spectrin anchorage complexes. Micrometric compartmentation might play a role in erythrocyte membrane deformability and fragility. 相似文献
93.
Emmanuelle Stoetzel Christiane Denys Jacques Michaux Sabrina Renaud 《Biological journal of the Linnean Society. Linnean Society of London》2013,109(3):599-621
North Africa is an intricate biogeographical region at the crossroads of immigration waves from tropical Africa and Asia. Species confined between various barriers (Atlas Mountains, arid environments such as the Sahara in the south, water masses such as the Mediterranean Sea in the north, and the Atlantic Ocean in the west) were generally forced to adapt locally to environmental changes instead of tracking their habitat by shifting their distribution area. The present study aims at providing first insight into the evolution of the genus Mus, and more specifically of the western Mediterranean species Mus spretus in this area. The study relies on the abundant Late Pleistocene and Middle Holocene fossil assemblage from the El Harhoura 2 cave (Rabat‐Témara, Morocco). This exceptional record was studied using geometric morphometrics applied to first upper and lower molars, constituting the most informative and best preserved fossil remains for such small rodents. Two main issues were addressed. (1) Geometric morphometrics was used to clarify taxonomic status and phylogenetic relationships among fossil and modern species in this area. Morphometric analysis revealed good discrimination of most modern and fossil species but failed to document intermediate forms tracing anagenetic evolution. Not mutually exclusive, the occurrence of complex processes of morphological evolution in this genus such as parallel evolution and the action of stabilizing selection may make it difficult to translate patterns of morphological evolution into phylogenetic conclusions. (2) The record was shown to document a sequence of intraspecific evolution of M. spretus. The morphology of the molars through the fossil record of El Harhoura 2 was surprisingly stable despite extensive modern variation. The limited temporal variation largely failed to correlate to palaeoenvironmental proxies. The mouse fossil record at El Harhoura 2 thus presents an intriguing case of morphological stasis despite extensive environmental changes. This long‐term stability may have been recently perturbed by anthropogenic factors including landscape changes and introduction of various competitors and predators, leading to a size reduction. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 599–621. 相似文献
94.
Background
Continuing efforts in development of non-invasive prenatal genetic tests have focused on the isolation of fetal nucleated red blood cells (NRBCs) from maternal blood for decades. Because no fetal cell-specific antibody has been described so far, the present study focused on the development of monoclonal antibodies (mAbs) to antigens that are expressed exclusively on fetal NRBCs.Methods: Mice were immunized with fetal erythroid cell membranes and hybridomas screened for Abs using a multi-parameter fluorescence-activated cell sorting (FACS). Selected mAbs were evaluated by comparative FACS analysis involving Abs known to bind erythroid cell surface markers (CD71, CD36, CD34), antigen-i, galactose, or glycophorin-A (GPA). Specificity was further confirmed by extensive immunohistological and immunocytological analyses of NRBCs from umbilical cord blood and fetal and adult cells from liver, bone marrow, peripheral blood, and lymphoid tissues.Results: Screening of 690 hybridomas yielded three clones of which Abs from 4B8 and 4B9 clones demonstrated the desired specificity for a novel antigenic structure expressed on fetal erythroblast cell membranes. The antigenic structure identified is different from known surface markers (CD36, CD71, GPA, antigen-i, and galactose), and is not present on circulating adult erythroid cells, except for occasional detectability in adult bone marrow cells.Conclusions:The new mAbs specifically bind the same or highly overlapping epitopes of a surface antigen that is almost exclusively expressed on fetal erythroid cells. The high specificity of the mAbs should facilitate development of simple methods for reliable isolation of fetal NRBCs and their use in non-invasive prenatal diagnosis of fetal genetic status. 相似文献95.
Christiane Baumert Marianne Günthel Sören Krawczyk Marc Hemmer Tom Wersig Andreas Langner Joséf Molnár Hermann Lage Andreas Hilgeroth 《Bioorganic & medicinal chemistry》2013,21(1):166-177
Novel series of N-benzyl 1,4-dihydropyridines have been prepared by facile syntheses. All relevant substituents of the molecular scaffold have been varied. The resulting compounds were biologically evaluated as P-glycoprotein (P-gp) inhibitors. Substitutions of the N-benzyl residue favour biological activity beside respective 3-ester functions. Most active compounds were further evaluated as multidrug resistance (MDR) modulators to restore the cytotoxic properties of varying daunorubicin applications. 相似文献
96.
Bruno Galy Dunja Ferring-Appel Christiane Becker Norbert Gretz Hermann-Josef Gröne Klaus Schümann Matthias W. Hentze 《Cell reports》2013,3(3):844-857
Highlights? Disruption of intestinal IRP function constrains iron absorption in adult mice ? IRPs must limit mucosal ferritin for efficient iron absorption ? IRPs control ferroportin directly and DMT1 directly or through HIF2α ? IRPs define a set point for hepcidin-mediated regulation of iron absorption 相似文献
97.
Lutz?HamannEmail author Alexander?Koch Saubashya?Sur Nadja?Hoefer Christiane?Glaeser Susanne?Schulz Michael?Gross Andre?Franke Ute?N?thlings Kai?Zacharowski Ralf?R?Schumann 《Immunity & ageing : I & A》2013,10(1):43
Background
The pro-inflammatory status of the elderly triggers most of the age-related diseases such as cancer and atherosclerosis. Atherosclerosis, the leading cause world wide of morbidity and death, is an inflammatory disease influenced by life-style and genetic host factors. Stimuli such as oxLDL or microbial ligands have been proposed to trigger inflammation leading to atherosclerosis. It has recently been shown that oxLDL activates immune cells via the Toll-like receptor (TLR) 4/6 complex. Several common single nucleotide polymorphisms (SNPs) of the TLR system have been associated with atherosclerosis. To investigate the role of TLR-6 we analyzed the association of the TLR-6 SNP Pro249Ser with atherogenesis.Results
Genotyping of two independent groups with CAD, as well as of healthy controls revealed a significant association of the homozygous genotype with a reduced risk for atherosclerosis (odds ratio: 0.69, 95% CI 0.51-0.95, P?=?0.02). In addition, we found a trend towards an association with the risk of restenosis after transluminal coronary angioplasty (odds ratio: 0.53, 95% CI 0.24-1.16, P?=?0.12). In addition, first evidence is presented that the frequency of this protective genotype increases in a healthy population with age. Taken together, our results define a role for TLR-6 and its genetic variations in modulating the inflammatory response leading to atherosclerosis.Conclusions
These results may lead to a better risk stratification, and potentially to an improved prophylactic treatment of high-risk populations. Furthermore, the protective effect of this polymorphism may lead to an increase of this genotype in the healthy elderly and may therefore be a novel genetic marker for the well-being during aging.98.
Tobias Bidon Christiane Frosch Hans G. Eiken Verena E. Kutschera Snorre B. Hagen Siv G. Aarnes Steven R. Fain Axel Janke Frank Hailer 《Molecular ecology resources》2013,13(3):362-368
We report a new approach for molecular sex identification of extant Ursinae and Tremarctinae bears. Two Y‐specific fragments (SMCY and 318.2) and one X‐specific fragment (ZFX) are amplified in a multiplex PCR, yielding a double test for male‐specific amplification and an internal positive control. The primers were designed and tested to be bear‐specific, thereby minimizing the risk of cross‐amplification in other species including humans. The high sensitivity and small amplicon sizes (100, 124, 160 base pairs) facilitate analysis of non‐invasively obtained DNA material. DNA from tissue and blood as well as from 30 non‐invasively collected hair and faeces yielded clear and easily interpretable results. The fragments were detected both by standard gel electrophoresis and automated capillary electrophoresis. 相似文献
99.
Eike Gallmeier Dominik C. Bader Lydia Kriegl Sabina Berezowska Hendrik Seeliger Burkhard G?ke Thomas Kirchner Christiane Bruns Enrico N. De Toni 《PloS one》2013,8(2)