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排序方式: 共有377条查询结果,搜索用时 15 毫秒
371.
372.
Jacobsen Kathryn H. Aguirre A. Alonso Bailey Charles L. Baranova Ancha V. Crooks Andrew T. Croitoru Arie Delamater Paul L. Gupta Jhumka Kehn-Hall Kylene Narayanan Aarthi Pierobon Mariaelena Rowan Katherine E. Schwebach J. Reid Seshaiyer Padmanabhan Sklarew Dann M. Stefanidis Anthony Agouris Peggy 《EcoHealth》2016,13(1):200-212
EcoHealth - As the Ebola outbreak in West Africa wanes, it is time for the international scientific community to reflect on how to improve the detection of and coordinated response to future... 相似文献
373.
The problem of microbial cell immobilization at present attracts the ever increasing attention of the scientists, since such organisms may be the source of various enzymes. Production of nizin by the immobilized cells of Str. lactis was studied. It was found that the cells of Str. lactis incorporated into polyacrylamide gel produced nizit on definite media. Still, the amount of the antibiotic was 2-3 times lower than in case of using free cells. The effect of a number of factors on the process of immobilization was studied and the influence of some factors, such as temperature, pH, aeration on nizin synthesis by the immobilized cells of the streptococcus was elucidated. Optimal conditions for nizin biosynthesis by the immobilized cells of Str. lactis were developed. 相似文献
374.
INÊS CATRY MARIA P. DIAS TERESA CATRY VSEVOLOD AFANASYEV JAMES FOX ALDINA M.A. FRANCO WILLIAM J. SUTHERLAND 《Ibis》2011,153(1):154-164
The population decline of the Lesser Kestrel Falco naumanni has been the subject of studies across its Western Palaearctic breeding range, but little is known about its use of pre‐migratory areas or African wintering quarters. We used geolocators to describe the temporal and spatial patterns of Portuguese Lesser Kestrel migration and wintering behaviour. Data on the complete migration were obtained from four individuals and another three provided further information. Prior to southward migration, Lesser Kestrels showed two different behaviours: northward‐orientated movements to Spain and movements in the proximity of the breeding area. Autumn migration took place mostly in late September; spring departures occurred mainly in the first half of February. Wintering grounds included Senegal, Mauritania and Mali, with individuals overlapping considerably in Senegal. Movements registered within the wintering grounds suggest itinerant behaviour in relation to local flushes of prey. During spring migration, birds crossed the Sahara Desert through Mauritania, Western Sahara and Morocco before passing over the Mediterranean to reach Portugal. Autumn migration lasted 4.8 ± 1.1 days, and spring migration lasted 4.1 ± 0.3 days. The mean daily flight range varied between approximately 300 and 850 km for an entire journey of around 2500 km. Effective protection of roosting sites in both pre‐migratory and wintering areas and maintaining grasshopper populations in Sahelian wintering quarters appear crucial in preserving this threatened migratory raptor across its African–Eurasian flyway. There was no evidence of any deleterious effects of fitting birds with loggers. 相似文献
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376.
A. V. Baranova 《Russian Journal of Genetics》2008,44(10):1160-1175
Subcutaneous and visceral adipose compartments act, not only as fatty acid depots, but also as active endocrine organs that undergo hyperplastic changes and significantly enhance their function in obesity. Adipokines and other proteins secreted by both adipocytes and stromal cells play a central role in peripheral insulin resistance and the metabolic syndrome (MS). Minor alleles of the adipokine genes substantially contribute to MS. The most important consequence of MS is low-level systemic inflammation supported by adiposespecific synthesis of proinflammatory soluble molecules. Proinflammatory signals are secreted into the bloodstream and spread to peripheral tissues that express their receptors. The signals provided by adipose tissue stimulate the development of secondary complications of MS, including cardiovascular disorders (CVDs) and nonalcoholic fatty liver disease. The review describes the physiological effects of adiponectin, leptin, resistin, visfatin, and apelin and the influence of the minor alleles of the adipokine genes on the development of the secondary complications of MS. 相似文献
377.
Margarita A. Baranova 《The Botanical review》1987,53(1):53-79
There is a long-standing confusion between morphologic and ontogenetic classifications of stomates. The earliest scheme, by Vesque (1889) was proposed as basically ontogenetic, but it was soon widely applied to mature leaves. The ontogenetic distinction between haplocheilic and syndetocheilic stomates in gymnosperms, proposed by Florin (1931, 1933) soon suffered a similar fate. Continuing studies over the past half-century have shown that stomatal ontogeny is only poorly correlated with the mature morphology. Efforts to combine ontogenetic and morphologic features in a single scheme have led to classifications so complex as to be impractical. The explicitly morphological classification by Metcalfe and Chalk (1950) is the foundation for the most widely used present scheme, in which some 14 morphological types are recognized. The distinctions among these types are conceptually useful, though often arbitrary in practice. 相似文献