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581.
Accessing genetic diversity for crop improvement 总被引:1,自引:0,他引:1
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Developing taste buds in the anterior mandibular floor of perihatching
chicks were studied by high voltage electron microscopic autoradiography in
order to identify proliferating gemmal cell types. Montaged profiles of 29
taste buds in five cases euthanized between embryonic day 21 and
posthatching day 2 were analyzed after a single [3H]thymidine injection
administered on embryonic day 16, 17 or 18. Results showed that dark cells
comprised 55% of identified (n = 900 cells) and 62% of labeled (n = 568
cells) gemmal cells as compared with light, intermediate, basal or
perigemmal bud cells. Dark cells had both a greater (P < 0.05) number of
labeled cells and a greater amount of label (grains/nucleus) than the other
four bud cell types, irrespective of injection day. The nuclear area
(micron 2) of dark cells was not significantly larger (P > 0.05) than
that of the other gemmal cell types and therefore cannot account for the
greater amount for label in the dark cells. Interestingly, only dark cells
showed a positive correlation (P < 0.003) between amount of label and
nuclear area. Results suggest that, during the perihatching period of
robust cell proliferation, dividing dark cells may give rise primarily, but
not exclusively, to dark cell progeny.
相似文献
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Maxime Lavoie Pierre Blanchette Serge Larivière Jean-Pierre Tremblay 《Population Ecology》2017,59(3):239-249
Temperate species occupying habitats at the northern limit of their geographical distribution are limited by weather and climatic conditions. Such conditions often directly affect population dynamics, and thus, influence shifts in distribution via changes in demographic parameters. We examined this question by following three distinct populations of wild turkeys inhabiting areas exposed to a gradient of meteorological conditions at the northern limit of the species distribution. Four years of radio-telemetry on 181 birds and monitoring of 95 nests revealed that population demographics of wild turkeys were influenced by snow depth, winter temperature and summer rainfall. During winter, survival of turkeys decreased drastically when snow depth remained >30 cm for >10 days and also decreased as temperatures got colder. In the spring, snow persistence delayed nest initiation, whereas nest survival was negatively affected by rainfall. Our findings show that the effects of critical meteorological factors such as snow and temperature can be compounded when both reach the limit of a species tolerance simultaneously. 相似文献
587.
Employing a Harm-Reduction Approach Between Women and Girls Within Indigenous Familial Relationships
Cooper Elizabeth Driedger S. Michelle Lavoie Josée G. 《Culture, medicine and psychiatry》2019,43(1):134-159
Culture, Medicine, and Psychiatry - It is important to recognize that experiences of racial and gendered violence are a sad legacy of colonialism. The experiences of historical trauma are on-going.... 相似文献
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Karine Couturier Stéphane Servais Harry Koubi Brigitte Sempore Marie-Hélène Sornay-Mayet Jean-Marie Cottet-Emard Dr. Jean-Marc Lavoie Roland Favier 《Obesity (Silver Spring, Md.)》2002,10(3):188-195
Objective: The aims of this study were to investigate some features of the metabolic profile and the body composition of male Lou/C rats and to examine whether these characteristics are strictly related to the food-intake reduction. Research Methods and Procedures: Fourteen-week-old male Lou/C rats were compared with age-matched male Wistar rats fed ad libitum (WAL) and another group of male Wistar rats whose food was chronically restricted (WFR) to the same amount as the Lou/C rats from weeks 3 to 14. Results: Food intake and body weight were significantly (p < 0.01) reduced in Lou/C compared with WAL rats, whereas these reductions were perfectly reproduced in WFR rats. Lou/C rats demonstrated lower relative weights of retroperitoneal (0.97 ± 0.07 vs. 1.67 ± 0.16 and 1.88 ± 0.15 g/100 g body) and epididymal (1.01 ± 0.02 vs. 1.62 ± 0.12 and 1.80 ± 0.11 g/100g body) fat depots than did the two other groups and no decrease in the percentage of carcass proteins, which was observed in the WFR rats. In addition, compared with the WFR group, the Lou/C rats showed lower plasma glucose levels (3.65 ± 0.14 vs. 4.72 ± 0.15 and 4.7 ± 0.19 mM); a tendency (p < 0.1) for lower liver glycogen concentrations; and similar levels of glycerol, free fatty acids, and β-hydroxybutyrate concentrations. Epinephrine and the relative weight of the adrenal glands were significantly (p < 0.01) lower in the Lou/C rats than in the WAL rats and the two other groups, respectively. Discussion: The ability of the Lou/C rats to accumulate less body fat than their equally food-restricted Wistar counterparts (WFR) suggests a difference in basal metabolism in this strain of rats that resembles obesity-resistant rats. 相似文献
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