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131.
Wnt signaling: an essential regulator of cardiovascular differentiation, morphogenesis and progenitor self-renewal 总被引:1,自引:0,他引:1
Emerging evidence indicates that Wnt signaling regulates crucial aspects of cardiovascular biology (including cardiac morphogenesis, and the self-renewal and differentiation of cardiac progenitor cells). The ability of Wnt signaling to regulate such diverse aspects of cardiovascular development rests on the multifarious downstream and tangential targets affected by this pathway. Here, we discuss the roles for Wnt signaling in cardiac and vascular development, and focus on the emerging role of Wnt signaling in cardiovascular morphogenesis and progenitor cell self-renewal. 相似文献
132.
Ethan B Solomon Sima Yaron Karl R Matthews 《Applied and environmental microbiology》2002,68(1):397-400
The transmission of Escherichia coli O157:H7 from manure-contaminated soil and irrigation water to lettuce plants was demonstrated using laser scanning confocal microscopy, epifluorescence microscopy, and recovery of viable cells from the inner tissues of plants. E. coli O157:H7 migrated to internal locations in plant tissue and was thus protected from the action of sanitizing agents by virtue of its inaccessibility. Experiments demonstrate that E. coli O157:H7 can enter the lettuce plant through the root system and migrate throughout the edible portion of the plant. 相似文献
133.
A variety of genetic evidence suggests that a gradient of Decapentaplegic (Dpp) activity determines distinct cell fates in the dorsal region of the Drosophila embryo, and that this gradient may be generated indirectly by an inverse gradient of the BMP antagonist Short gastrulation (Sog). It has been proposed that Sog diffuses dorsally from the lateral neuroectoderm where it is produced, and is cleaved and degraded dorsally by the metalloprotease Tolloid (Tld). Here we show directly that Sog is distributed in a graded fashion in dorsal cells and that Tld degradation limits the levels of Sog dorsally. In addition, we find that Dynamin-dependent retrieval of Sog acts in parallel with degradation by Tld as a dorsal sink for active Sog. 相似文献
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Domination among strategies in an evolutionary game implies that the geometric mean of the frequencies of certain strategies—the unfit—approaches zero. However, as we show by example no one strategy need be eliminated in the limit. 相似文献
136.
The Influence of Exogenous Testosterone on the Dynamics of Nestling Provisioning in Dark-Eyed Juncos 总被引:1,自引:0,他引:1
Ethan D. Clotfelter C. Ray Chandler† Val Nolan Jr ‡ & Ellen D. Ketterson‡ 《Ethology : formerly Zeitschrift fur Tierpsychologie》2007,113(1):18-25
In many songbird species, application of exogenous testosterone (T) during the breeding season has the general effects of reducing male parental investment and increasing allocation of time and energy to mating. Most studies record the number of feeding trips made by males as a function of their hormone treatment, but few have investigated the ways in which testosterone affects the dynamics of male and female provisioning behavior or the quantity of food delivered by males. We attempt to fill these gaps in our understanding of testosterone and male parental effort by utilizing data from a long‐term study on the behavioral endocrinology of the dark‐eyed junco (Junco hyemalis). We found that male and female feeding rates covaried positively, although to different degrees, throughout the nestling period, but that this relationship was degraded in pairs in which males were given T implants. We also found that the coefficients of variation in the duration of intervals between successive feeding trips by males and females were highly positively related in broods of older nestlings. Male hormone treatment, however, had no effect on the coefficients of variation in either male or female feeding intervals. Finally, we examined the quantity of prey delivered by males and found no significant effect of hormone treatment. 相似文献
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Mohammed Mamdani Vernell Williamson Gowon O. McMichael Tana Blevins Fazil Aliev Amy Adkins Laura Hack Tim Bigdeli Andrew D. van der Vaart Bradley Todd Web Silviu-Alin Bacanu Gursharan Kalsi COGA Consortium Kenneth S. Kendler Michael F. Miles Danielle Dick Brien P. Riley Catherine Dumur Vladimir I. Vladimirov 《PloS one》2015,10(9)
140.
Kenyi Saito-Diaz Hassina Benchabane Ajit Tiwari Ai Tian Bin Li Joshua J. Thompson Annastasia S. Hyde Leah M. Sawyer Jeanne N. Jodoin Eduardo Santos Laura A. Lee Robert J. Coffey R. Daniel Beauchamp Christopher S. Williams Anne K. Kenworthy David J. Robbins Yashi Ahmed Ethan Lee 《Developmental cell》2018,44(5):566-581.e8