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61.
Leif Egil Loe Christophe Bonenfant Erling L. Meisingset Atle Mysterud 《European Journal of Wildlife Research》2012,58(1):195-203
Species distribution models (SDMs) are popular in conservation and management of a wide array of taxa. Often parameterized
with coarse GIS-based environmental maps, they perform well in macro-ecological settings but it is debated if the models can
predict distribution within broadly suitable “known” habitats of interest to local managers. We parameterized SDMs with GIS-derived
environmental variables and location data from 82 GPS-collared female red deer (Cervus elaphus) from two study areas in Norway. Candidate GLM models were fitted to address the effect of spatial scale (landscape vs. home
range), sample size, and transferability between study areas, with respect to predictability (AUC) and explained variance
(Generalized R
2 and deviance). The landscape level SDM captured variation in deer distribution well and performed best on all diagnostic
measures of model quality, caused mainly by a trivial effect of avoidance of non-habitat (barren mountains). The home range
level SDMs were far less predictable and explained comparatively little variation in space use. Landscape scale models stabilized
at the low sample size of 5–10 individuals and were highly transferrable between study areas implying a low degree of individual
variation in habitat selection at this scale. It is important to have realistic expectations of SDMs derived from digital
elevation models and coarse habitat maps. They do perform well in highlighting potential habitat on a landscape scale, but
often miss nuances necessary to predict more fine-scaled distribution of wildlife populations. Currently, there seems to be
a trade-off between model quality and usefulness in local management. 相似文献
62.
Shinichi Sunagawa Jens Roat Kultima Paul I Costea Aurélien Amiot Jürgen Böhm Francesco Brunetti Nina Habermann Rajna Hercog Moritz Koch Alain Luciani Daniel R Mende Martin A Schneider Petra Schrotz‐King Christophe Tournigand Jeanne Tran Van Nhieu Takuji Yamada Jürgen Zimmermann Vladimir Benes Matthias Kloor Cornelia M Ulrich Magnus von Knebel Doeberitz Iradj Sobhani Peer Bork 《Molecular systems biology》2014,10(11)
Several bacterial species have been implicated in the development of colorectal carcinoma (CRC),
but CRC-associated changes of fecal microbiota and their potential for cancer screening remain to be
explored. Here, we used metagenomic sequencing of fecal samples to identify taxonomic markers that
distinguished CRC patients from tumor-free controls in a study population of 156 participants.
Accuracy of metagenomic CRC detection was similar to the standard fecal occult blood test (FOBT) and
when both approaches were combined, sensitivity improved > 45% relative to the FOBT,
while maintaining its specificity. Accuracy of metagenomic CRC detection did not differ
significantly between early- and late-stage cancer and could be validated in independent patient and
control populations (N = 335) from different countries. CRC-associated
changes in the fecal microbiome at least partially reflected microbial community composition at the
tumor itself, indicating that observed gene pool differences may reveal tumor-related
host–microbe interactions. Indeed, we deduced a metabolic shift from fiber degradation in
controls to utilization of host carbohydrates and amino acids in CRC patients, accompanied by an
increase of lipopolysaccharide metabolism. 相似文献
63.
64.
Christophe. J Queval Ok-Ryul Song Vincent Delorme Raffaella Iantomasi Romain Veyron-Churlet Nathalie Deboosère Valérie Landry Alain Baulard Priscille Brodin 《Journal of visualized experiments : JoVE》2014,(83)
Despite the availability of therapy and vaccine, tuberculosis (TB) remains one of the most deadly and widespread bacterial infections in the world. Since several decades, the sudden burst of multi- and extensively-drug resistant strains is a serious threat for the control of tuberculosis. Therefore, it is essential to identify new targets and pathways critical for the causative agent of the tuberculosis, Mycobacterium tuberculosis (Mtb) and to search for novel chemicals that could become TB drugs. One approach is to set up methods suitable for the genetic and chemical screens of large scale libraries enabling the search of a needle in a haystack. To this end, we developed a phenotypic assay relying on the detection of fluorescently labeled Mtb within fluorescently labeled host cells using automated confocal microscopy. This in vitro assay allows an image based quantification of the colonization process of Mtb into the host and was optimized for the 384-well microplate format, which is proper for screens of siRNA-, chemical compound- or Mtb mutant-libraries. The images are then processed for multiparametric analysis, which provides read out inferring on the pathogenesis of Mtb within host cells. 相似文献
65.
Yi-Shiang Huang Virginie Bertrand Dimitriya Bozukova Christophe Pagnoulle Christine Labrugère Edwin De Pauw Marie-Claire De Pauw-Gillet Marie-Christine Durrieu 《PloS one》2014,9(12)
Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient''s age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO. On the other hand, we have previously demonstrated that the adhesion of LECs is favored on hydrophobic compared to hydrophilic materials. By combining these two facts and contemporary knowledge in PCO development via the EMT pathway, we propose a biomimetically inspired strategy to promote LEC adhesion without de-differentiation to reduce the risk of PCO development. By surface grafting of a cell adhesion molecule (RGD peptide) onto the conventional hydrophilic acrylic IOL material, the surface-functionalized IOL can be used to reconstitute a capsule-LEC-IOL sandwich structure, which has been considered to prevent PCO formation in literature. Our results show that the innovative biomaterial improves LEC adhesion, while also exhibiting similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties compared to the starting material. In addition, compared to the hydrophobic IOL material, our bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression, which is the crucial pathway to induce PCO. The in vitro assays suggest that this biomaterial has the potential to reduce the risk factor of PCO development. 相似文献
66.
Genetic dissection of sex determinism, inflorescence morphology and downy mildew resistance in grapevine 总被引:1,自引:0,他引:1
Elisa Marguerit Christophe Boury Aurélie Manicki Martine Donnart Gisèle Butterlin Alice Némorin Sabine Wiedemann-Merdinoglu Didier Merdinoglu Nathalie Ollat Stéphane Decroocq 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(7):1261-1278
A genetic linkage map of grapevine was constructed using a pseudo-testcross strategy based upon 138 individuals derived from
a cross of Vitis vinifera Cabernet Sauvignon × Vitis riparia Gloire de Montpellier. A total of 212 DNA markers including 199 single sequence repeats (SSRs), 11 single strand conformation
polymorphisms (SSCPs) and two morphological markers were mapped onto 19 linkage groups (LG) which covered 1,249 cM with an
average of 6.7 cM between markers. The position of SSR loci in the maps presented here is consistent with the genome sequence.
Quantitative traits loci (QTLs) for several traits of inflorescence and flower morphology, and downy mildew resistance were
investigated. Two novel QTLs for downy mildew resistance were mapped on linkage groups 9 and 12, they explain 26.0–34.4 and
28.9–31.5% of total variance, respectively. QTLs for inflorescence morphology with a large effect (14–70% of total variance
explained) were detected close to the Sex locus on LG 2. The gene of the enzyme 1-aminocyclopropane-1-carboxylic acid synthase, involved in melon male organ development
and located in the confidence interval of all QTLs detected on the LG 2, could be considered as a putative candidate gene
for the control of sexual traits in grapevine. Co-localisations were found between four QTLs, detected on linkage groups 1,
14, 17 and 18, and the position of the floral organ development genes GIBBERELLIN INSENSITIVE1, FRUITFULL, LEAFY and AGAMOUS. Our results demonstrate that the sex determinism locus also determines both flower and inflorescence morphological traits. 相似文献
67.
68.
Fran?ois Bartoli David Coinchelin Christophe Robin Guillaume Echevarria 《Plant and Soil》2012,350(1-2):99-115
Aims
The primary aim of this study was to investigate the impact of active nickel and cadmium transport, transpiration and shoot biomass production on Ni and Cd accumulation in the leaves of the Ni-hyperaccumulator Leptoplax emarginata. A secondary objective was to observe the effects of various concentrations of nickel and cadmium in solutions on the plant growth and ecophysiological characteristics of these plants. Finally, the study sought to identify possible nickel and cadmium concentration gradients in solution as a function of the root distance.Methods
The Intact Plant Transpiration Stream Concentration Factor (TSCF=xylem/solution solute concentration ratio) was determined for both Ni and Cd and for the selected intact transpiring Ni-hyperaccumulator Leptoplax emarginata, cultivated on two contrasting fertilized and Ni-Cd-contaminated sandy porous media (rhizotrons with central root compartments, linked to Mariotte tubes operated at ?1?kPa). IPTSCFNi and IPTSCFCd were calculated as the ratios between the hyperaccumulator plant’s nickel or cadmium mass in the leaves and the nickel or cadmium concentration in solution by the volume of water transpired during the period of culture. Plant growth characteristics and gas exchanges were also recorded.Results
IPTSCF values were much greater than 1 (IPTSCFNi?=?5.2?±?0.9 and IPTSCFCd?=?4.4?±?0.6) whatever the amount of available Ni and Cd. This characterized a predominantly active plant metal uptake. Moreover, biological regulation was reported: plant growth and transpiration were significantly lower for hyperaccumulator plants cultivated in sand which was rich in available Ni and Cd, than for hyperaccumulator plants cultivated in topsoil, poor in available Ni and Cd. In the soil rhizosphere, capillary flow was related to transpiration and a depletion pattern was developed for Ni and sometimes for Cd.Conclusions
Overall, the Intact Plant Transpiration Stream Concentration Factor appeared to be a relevant metal bioconcentration factor taking into account the predominant type of metal transport from roots to leaves, plant growth and transpiration coupling and metal availability. IPTSCFNi and IPTSCFCd values were much greater than 1 and similar whatever the amount of available Ni and Cd. This characterized a predominantly active plant combining Ni and Cd uptake and biological regulations dependent of the Ni and Cd concentrations in solution. 相似文献69.
Jessica R. Benson Jiameng Xu Derek M. Moynes Tamia K. Lapointe Christophe Altier Stephen J. Vanner Alan E. Lomax 《Cell and tissue research》2014,356(2):309-317
Sensitization of dorsal root ganglia (DRG) neurons is an important mechanism underlying the expression of chronic abdominal pain caused by intestinal inflammation. Most studies have focused on changes in the peripheral terminals of DRG neurons in the inflamed intestine but recent evidence suggests that the sprouting of central nerve terminals in the dorsal horn is also important. Therefore, we examine the time course and reversibility of changes in the distribution of immunoreactivity for substance P (SP), a marker of the central terminals of DRG neurons, in the spinal cord during and following dextran sulphate sodium (DSS)-induced colitis in mice. Acute and chronic treatment with DSS significantly increased SP immunoreactivity in thoracic and lumbosacral spinal cord segments. This increase developed over several weeks and was evident in both the superficial laminae of the dorsal horn and in lamina X. These increases persisted for 5 weeks following cessation of both the acute and chronic models. The increase in SP immunoreactivity was not observed in segments of the cervical spinal cord, which were not innervated by the axons of colonic afferent neurons. DRG neurons dissociated following acute DSS-colitis exhibited increased neurite sprouting compared with neurons dissociated from control mice. These data suggest significant colitis-induced enhancements in neuropeptide expression in DRG neuron central terminals. Such neurotransmitter plasticity persists beyond the period of active inflammation and might contribute to a sustained increase in nociceptive signaling following the resolution of inflammation. 相似文献
70.
Cécile Faure Béatrice Morio Philippe Chafey Servane Le Plénier Philippe Noirez Voahangy Randrianarison‐Huetz Luc Cynober Christian Aussel Christophe Moinard 《Proteomics》2013,13(14):2191-2201
Citrulline (Cit) actions on muscle metabolism remain unclear. Those latter were investigated using a proteomic approach on Tibialis muscles from male Sprague‐Dawley rats. At 23 months of age, rats were either fed ad libitum (AL group) or subjected to dietary restriction for 12 weeks. At the end of the restriction period, one group of rats was euthanized (R group) and two groups were refed for one week with a standard diet supplemented with nonessential amino acids group or Cit (CIT group). Results of the proteomic approach were validated using targeted Western blot analysis and assessment of gene expression of the related genes. Maximal activities of the key enzymes involved in mitochondrial functioning were also determined. Cit supplementation results in a significant increase in the protein expression of the main myofibrillar constituents and of a few enzymes involved in glycogenolysis and glycolysis (CIT vs. AL and R, p < 0.05). Conversely, the expression of oxidative enzymes from Krebs cycle and mitochondrial respiratory chain was significantly decreased (CIT vs. AL, p < 0.05). However, maximal activities of key enzymes of mitochondrial metabolism were not significantly affected, except for complex 1 which presented an increased activity (CIT vs. AL and R, p < 0.05). In conclusion, Cit supplementation increases expression of the main myofibrillar proteins and seems to induce a switch in muscle energy metabolism, from aerobia toward anaerobia. 相似文献