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It has been suggested that the relation between diet and breast cancer may depend on estrogen receptor (ER) status. We examined the responses to a self-administered questionnaire on frequency of consumption of various foods by 493 women with breast cancer (160 with ER-negative tumours and 333 with ER-positive tumours) and 527 controls whose menopausal status was known. Analysis of the reported consumption of foods selected for their fat or carotene content showed no clear distinction in dietary factors between the ER-negative and ER-positive groups. Frequent consumption of meat fats generally increased the risk of both ER-negative and ER-positive tumours; there were no clear trends in risk associated with vegetable consumption for either ER group. Fish was the only item affecting the risk for ER-negative and ER-positive tumours differently, frequent consumption reducing the risk for the former (p = 0.02). The results do not support the hypothesis that ER status influences the relation between dietary fat consumption and risk of breast cancer. 相似文献
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An airlift reactor with double net draft tubes was developed. A sparger was located between the two draft tubes. The draft tubes had a significant effect on breaking bubbles into smaller ones. The assessment of the reactor performance was based on gas holdup, mixing time, and volumetric mass transfer coefficient. The proposed reactor had higher gas holdup and volumetric mass transfer coefficient, and lower mixing time in comparison with those of the bubble column. Application of the proposed reactor to fermentation of Saccharomyces cerevisiae demonstrated that the cultivation time was significantly shortened. 相似文献
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swinger: a user‐friendly computer program to establish captive breeding groups that minimize relatedness without pedigree information 下载免费PDF全文
Jonathan Sandoval‐Castillo Catherine R. M. Attard Shashikanth Marri Chris J. Brauer Luciana M. Möller Luciano B. Beheregaray 《Molecular ecology resources》2017,17(2):278-287
Captive breeding programmes are often a necessity for the continued persistence of a population or species. They typically have the goal of maintaining genetic diversity and minimizing inbreeding. However, most captive breeding programmes have been based on the assumption that the founding breeders are unrelated and outbred, even though in situ anthropogenic impacts often mean these founders may have high relatedness and substantial inbreeding. In addition, polygamous group‐breeding species in captivity often have uncertain pedigrees, making it difficult to select the group composition for subsequent breeding. Molecular‐based estimates of relatedness and inbreeding may instead be used to select breeding groups (≥two individuals) that minimize relatedness and filter out inbred individuals. swinger constructs breeding groups based on molecular estimates of relatedness and inbreeding. The number of possible combinations of breeding groups quickly becomes intractable by hand. swinger was designed to overcome this major issue in ex situ conservation biology. The user can specify parameters within swinger to reach breeding solutions that suit the mating system of the target species and available resources. We provide evidence of the efficiency of the software with an empirical example and using simulations. The only data required are a typical molecular marker data set, such as a microsatellite or SNP data set, from which estimates of inbreeding and pairwise relatedness may be obtained. Such molecular data sets are becoming easier to gather from non‐model organisms with next‐generation sequencing technology. swinger is an open‐source software with a user‐friendly interface and is available at http://www.molecularecology.flinders.edu.au/molecular-ecology-lab/software/swinger/swinger/ and https://github.com/Yuma248/Swinger . 相似文献
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Antarctic fish, such as the Trematomus bernacchii, living at −1.9°C maintain a serum osmolality of around 600 mOsm kg−1, nearly twice that of temperate fish. Upon warm acclimation, Antarctic fish significantly lower their serum osmolality. It
has been suggested that this response to warm acclimation is due to stress. The purpose of this study was to determine, whether
upon warm acclimation there was a change in the levels of the stress hormone cortisol and hematocrit associated with the decrease
in serum osmolality. T. bernacchii were warm acclimated up to 4 weeks and serum osmolality, cortisol and hematocrit were measured. Upon warm acclimation to
+1.6 and +3.8°C over the course of 4 weeks, T. bernacchii significantly lowered their serum osmolality (from 547 ± 4 mOsm kg−1 to 494 ± 6 and 489 ± 4 mOsm kg−1, respectively), yet did not alter their serum cortisol (29 ± 6 nl ml−1) or hematocrit (22 ± 1%) levels. These results suggest that warm acclimation does not induce a stress response in T. bernacchii. 相似文献
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Kisseberth N Brauer G Grosser B Potter CS Carragher B 《Journal of structural biology》1999,125(2-3):229-234
JavaScope is a Web-based java applet that implements an "exploration/browser" tool for operating a Philips CM200 transmission electron microscope and viewing digital images remotely. The primary use of the application is as a collaborative tool for remote consultations. 相似文献