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201.
202.
Twenty‐five–year survival for aboriginal and caucasian children with congenital heart defects in Western Australia, 1980 to 2010 下载免费PDF全文
203.
Simon D. Rees Glenda M. Orledge Michael W. Bruford Andrew F. G. Bourke 《Conservation Genetics》2010,11(3):823-834
Social Hymenoptera have been relatively little studied in terms of conservation genetics even though their sociality and complementary
sex determination potentially influence the interaction of genetics with extinction risk. Using microsatellite markers, we
investigated the social and genetic structure of nests and populations of the Black Bog Ant Formica picea at four sites in the UK, where this habitat specialist has a localized and fragmented range. Nests were weakly polygynous
(effective queen number, 4–27 per nest) with low worker relatedness. Isolation by distance tended to be present within sites,
indicating limited dispersal, but inbreeding was rare. The four study sites fell into three main populations (two in South
Wales, one in southern England). We conclude that, although UK F. picea populations are not at immediate risk from genetic factors, their limited dispersal abilities at both within- and between-site
scales should inform conservation management decisions. 相似文献
204.
P. M. Austin Bourke 《International journal of biometeorology》1963,7(2):121-125
Summary A more scientific approach to agriculture generally, coupled with the interest of the emergent nations of the world in a planned rural development, has led to a boom in agricultural meteorology. Major developments include an improvement in interdisciplinary communication at both the national and international level, a move toward standardization with the publication of the WMO GUIDE TO AGRICULTURAL METEOROLOGICAL PRACTICES, and the application of the principles of agroclimatic classification, in a pilot project, to the arid and semi-arid zones of the Near East. Other advances are recorded in such questions as the responses of crops and farm animals to weather conditions, the forecasting of agricultural diseases and pests, and the effect of environmental factors on the storage of agricultural products. An intensified research effort is being devoted to long-term weather forecasting for agriculture,and to questions of soil moisture balance. 相似文献
205.
Ryan E. Brock Liam P. Crowther David J. Wright David S. Richardson Claire Carvell Martin I. Taylor Andrew F. G. Bourke 《Proceedings. Biological sciences / The Royal Society》2021,288(1944)
Genetic bottlenecks can limit the success of populations colonizing new ranges. However, successful colonizations can occur despite bottlenecks, a phenomenon known as the genetic paradox of invasion. Eusocial Hymenoptera such as bumblebees (Bombus spp.) should be particularly vulnerable to genetic bottlenecks, since homozygosity at the sex-determining locus leads to costly diploid male production (DMP). The Tree Bumblebee (Bombus hypnorum) has rapidly colonized the UK since 2001 and has been highlighted as exemplifying the genetic paradox of invasion. Using microsatellite genotyping, combined with the first genetic estimates of DMP in UK B. hypnorum, we tested two alternative genetic hypotheses (‘bottleneck’ and ‘gene flow’ hypotheses) for B. hypnorum''s colonization of the UK. We found that the UK population has not undergone a recent severe genetic bottleneck and exhibits levels of genetic diversity falling between those of widespread and range-restricted Bombus species. Diploid males occurred in 15.4% of reared colonies, leading to an estimate of 21.5 alleles at the sex-determining locus. Overall, the findings show that this population is not bottlenecked, instead suggesting that it is experiencing continued gene flow from the continental European source population with only moderate loss of genetic diversity, and does not exemplify the genetic paradox of invasion. 相似文献
206.
Addition of norepinephrine or isoproterenol to primary cultures started from the brains of 1-3 day old rats caused up to 200-fold increases in cAMP levels, which reached a maximum by 5-10 min and then declined. This effect was studied in detail for norepinephrine. The rise in cAMP levels was followed by morphological changes, in which up to 65% of the cells exhibited an astrocyte-like morphology, and 2-3 fold increases in carbonic anhydrase and (Na+-K+) ATPase activities. However, morphological transformation also occurred after much smaller increases in total cAMP levels. These effects on cell morphology and enzyme activities reached a maximum 1-2 h after addition of norepinephrine and then declined. Carbonic anhydrase activity was found both in the particulate and post 100,000 g supernatant fractions from homogenates of these cultured cells, and in the latter case the activity was activated 3-fold by addition of cAMP. The significance of these obscrvations on the cellular localization of, and functional role for similar increases in cAMP in brain tissue is discussed. 相似文献
207.
William M. Fogarty Catherine T. Kelly Anne C. Bourke Evelyn M. Doyle 《Biotechnology letters》1994,16(5):473-478
Summary
Pseudomonas sp. IMD 353 produced an extracellular consititutive maltotetraose-forming amylase in a medium containing glucose (or fructose), yeatex and mineral salts. Km values on starch, amylopectin and short chain amylose were 4.0, 2.8 and 3.0 mg/ml, repectively. Sulphydryl reducing agents activated the enzyme considerably, as did Co2+ and Mn2+. 相似文献
208.