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931.
Barbara Tillmann Pierre Jolic?ur Masami Ishihara Nathalie Gosselin Olivier Bertrand Yves Rossetti Isabelle Peretz 《PloS one》2010,5(4)
Congenital amusia is a neurogenetic disorder of music processing that is currently ascribed to a deficit in pitch processing. A recent study challenges this view and claims the disorder might arise as a consequence of a general spatial-processing deficit. Here, we assessed spatial processing abilities in two independent samples of individuals with congenital amusia by using line bisection tasks (Experiment 1) and a mental rotation task (Experiment 2). Both amusics and controls showed the classical spatial effects on bisection performance and on mental rotation performance, and amusics and controls did not differ from each other. These results indicate that the neurocognitive impairment of congenital amusia does not affect the processing of space. 相似文献
932.
Blood and cloacal swab sampling for avian influenza monitoring has no effect on survival rates of free‐ranging ducks 下载免费PDF全文
Matthieu Guillemain Jocelyn Champagnon Marie‐Lucile Gourlay‐Larour Francois Cavallo Anne‐Laure Brochet Jean Hars Gregoire Massez Thierry George Pierre‐Yves Perroi Veronique Jestin Alain Caizergues 《Ibis》2015,157(4):743-753
Concerns about the spread of avian influenza viruses (AIVs) have led to cloacal swab sampling of hundreds of thousands of birds worldwide as part of AIV surveillance schemes, but the effects of cloacal swabbing have not been adequately evaluated. We tested for differences between swabbed, swabbed and bled, and non‐sampled wild ducks in terms of live re‐encounter and dead recoveries for Common Pochard Aythya ferina and Tufted Duck Aythya fuligula, and also determined re‐encounter and recovery rates for Mallard Anas platyrhynchos and Common Teal Anas crecca. No effects of sampling methods were detected, except in Teal. Re‐encounter rates were lower in sampled Teal than in controls, with annual re‐encounter probabilities being 25% and 35% lower in males and females, respectively. Teal possibly left or avoided sampling sites, or sought sites where they were less detectable after sampling. In general, no deleterious effects were found, suggesting that cloacal swabbing and blood sampling are suitable methods for conducting AIV surveillance in ducks. 相似文献
933.
934.
In this work we consider a structured population with groups and subgroups of individuals. The intra-group dynamics is assumed to be fast in comparison with the inter-group dynamics. We study linear discrete models where the slow dynamics is represented by a single matrix and the fast dynamics is described by means of the first k terms of a converging sequence of different matrices. The number k can be interpreted as the ratio between the two time scales.The aim of this work is to extend aggregation techniques to the case of fast changing environments. The main idea of aggregation is to build up a new system, with lower dimension, that summarizes the information concerning the fast process. This "aggregated" system provides essential information on the original one. It is shown that the asymptotic behavior of the original system can be approximated by the asymptotic behavior of the aggregated system when the ratio between the two time scales is large enough.We present an example of an age structured population in a patchy environment. The migration process is assumed to be fast in comparison with the demographic process. Numerical simulations illustrate that the asymptotic growth rate and the stable age distribution of the population in the original and the aggregated systems are getting closer as the ratio k increases. 相似文献
935.
936.
Pierre Bennoun 《BBA》1970,216(2):357-363
Reoxidation of the fluorescence quencher “Q” in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea
Reoxidation of the fluorescence quencher Q in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea shows the following properties:
It is sensitive to very low concentrations of hydroxylamine (a few μM).
It corresponds to a back reaction between Q− and the primary oxidant Z+ formed in the light. A part of this back reaction gives rise to luminescence emission.
Within the range we studied the kinetic of reoxidation is second order with regards to Q−. 相似文献
937.
The quantification of -acetolactate (AAL) extracellular oxidative decarboxylation during an AAL overproducing strain culture shows that this reaction is at the origin of about 90% of the diacetyl production and that only a small proportion of extracellular AAL is readily transformed to diacetyl. These results, compared with previous ones obtained with a non AAL accumulating strain, allow research options to be put forward for the improvement of microbiological diacetyl production. 相似文献
938.
Long-term effects of iron: Zinc interactions on growth in rats 总被引:1,自引:0,他引:1
Bouglé D Isfaoun A Bureau F Neuville D Jauzac P Arhan P 《Biological trace element research》1999,67(1):37-48
The influence of iron (Fe) on the bioavailability and functional status of zinc (Zn) was studied in young rats using metabolic
balances and tissue dosages, which were compared to growth. Diets supplied adequate intakes of Fe (45 and 300 mg/kg diet)
and Zn (14 and 45 mg/kg) for 2 mo. Two metabolic balance determinations were performed that were correlated for Zn and Fe
during the first and the last weeks of the study.
A significant effect of Fe supply, but not of Zn was displayed on Fe absorption; both Fe and Zn diet concentrations had a
significant influence on Zn absorption.
Fe and Zn organ contents were significantly correlated with the amount absorbed during the two metabolic balances. There was
a positive correlation between liver and muscle Fe and Fe absorption, and Fe absorption and muscle Zn, as well as a negative
one with liver Zn; a positive correlation was displayed between Zn absorption and Zn organ content. No correlation was found
between Zn absorption and Fe tissue content.
Growth was correlated with Zn, but not with Fe absorption during both balances. A positive correlation was displayed between
growth and Zn liver content, and a negative one with Fe liver content. Care must be taken to give growing subjects balanced
diets or supplementation, since the negative interactions between these trace elements are likely to persist as long as the
diet is given. 相似文献
939.
Mucins have been implicated in tumor-associated immunosuppression. The possibility that colon cancer mucin (CCM) may modulate
T-helper 1 (TH1) activity was evaluated by investigating its effect on the production of interleukin-2 (IL-2) by CD4+ cells, a process that requires antigen-specific and costimulatory signals. Methods: CCM was purified from human colorectal cancer cells by gel-exclusion fast-pressure liquid chromatography. Cytokine production
of purified CD4+ cells was evaluated at the protein and gene level in the presence of a phorbol ester or an anti-CD3 monoclonal antibody (mAb)
plus mAb against the CD28 costimulatory receptor to mimic two-signal activation. Results: Soluble CCM, which contains mucins MUC2 as well as MUC1, inhibited IL-2 mRNA expression and secretion of CD4+ stimulated with a phorbol ester or an anti-CD3 mAb plus anti-CD28 mAb. Pretreatment of CD4+ cells with anti-CD28 mAb abrogated the suppressive effects of CCM on IL-2 production, and flow cytometry showed decreased
binding of anti-CD28 mAb to its receptor in the presence of mucin. In addition, Ca2+ mobilization after T cell receptor cross-linking with anti-CD3 mAb was maintained in the presence of CCM. Although interferon
γ production was also diminished, CCM did not induce a general inhibition of cytokine production, nor did it decrease cell
viability. Macrophage inflammatory protein 1α production was up-regulated; the production of IL-10 and transforming growth
factor β was unchanged. Conclusions: The results indicate that CCM can alter TH1 activity and suggest that the modulation of costimulatory interactions is involved.
They provide another mechanism of immunosuppression mediated by these highly expressed tumor products.
Received: 23 March 1999 / Accepted: 3 August 1999 相似文献
940.
Microtubule alteration is an early cellular reaction to the metabolic challenge in ischemic cardiomyocytes 总被引:5,自引:0,他引:5
Vandroux D Schaeffer C Tissier C Lalande A Bès S Rochette L Athias P 《Molecular and cellular biochemistry》2004,258(1-2):99-108
Cytoskeleton damage, particularly microtubule (MT) alterations, may play an important role in the pathogenesis of ischemia-induced myocardial injury. However, this disorganization has been scarcely confirmed in the cellular context. We evaluated MT network disassembly in myoblast cell line H9c2 and in neonatal rat cardiomyocytes in an in vitro substrate-free hypoxia model of simulated ischemia (SI). After different duration of SI from 30 up to 180 min, the cells were fixed and the microtubule network was revealed by immunocytochemistry. The microtubule alterations were quantified using a house-developed image analysis program. Additionally, the tubulin fraction were extracted and quantified by Western blotting. The cell respiration, the release of cellular LDH and the cell viability were evaluated at the same periods. An early MT disassembly was observed after 60 min of SI. The decrease in MT fluorescence intensity at 60 and 90 min was correlated with a microtubule disassembly. Conversely, SI-induced significant LDH release (35%) and decrease in cell viability (34%) occurred after 120 min only. These results suggest that the simulated ischemia-induced changes in MT network should not be considered as an ultrastructural hallmark of the cell injury and could rather be an early ultrastructural correlate of the cellular reaction to the metabolic challenge. 相似文献