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Ross DA Whitmarsh RB Ali SA Boudreaux JE Coleman R Fleisher RL Girdler R Manheim F Matter A Nigrini C Stoffers P Supko PR 《Science (New York, N.Y.)》1973,179(4071):377-380
Recent drilling in the Red Sea has shown that much of the basin is underlain by evaporites of a similar age to that of evaporites found in the Mediterranean Sea. These evaporites and their structural positions indicate that other brine areas are present-and, indeed, several others have been discovered. 相似文献
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Wen-Hung Twan Hua-Fang Wu Jiang-Shiou Hwang Yan-Horn Lee Ching-Fong Chang 《Fish physiology and biochemistry》2005,31(2-3):111-115
Most broadcast spawning scleractinian corals synchronously release gametes during a brief annual spawning period. In southern
Taiwan, the mass spawning of scleractinians occurs in lunar mid-March. Endocrine system has been proposed to play important
roles in this annual phenomenon. A scleractinian coral, Euphyllia ancora has been selected as a model for the hormones and reproduction studies. We detected the presence of estradiol (E2), testosterone
(T), glucuronided E2, glucuronided T, aromatase, immunoreactive (ir)GnRH in coral polyps E. ancora. Annual profiles of sex steroids, aromatase, and irGnRH have also been characterized. We found the parallel increases in
irGnRH concentrations, aromatase activity and free E2 and glucuronided E2 concentrations at the time of coral mass spawning.
The stimulation of mammalian (m)GnRH agonist in the increased aromatase activity and sex steroid concentrations was also observed
in corals. Coral extracts (irGnRH) and mGnRH agonist had a similar dose-dependent effect on luteinizing hormone release in
black porgy fish pituitary cells (in vitro). In conclusion, our data suggest that irGnRH and glucuronided E2 may play important
roles in the control of reproduction and mass spawning in corals. Corals already evolved the vertebrate-type hormone system
in the sexual reproduction. 相似文献
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Twan Stoffers Antonie D. Buijse Johan A. J. Verreth Leopold A. J. Nagelkerke 《Fish and Fisheries》2022,23(1):162-182
The large-scale degradation of riparian ecotones and of the connectivity between rivers and their floodplains has resulted in a drastic decline of rheophilic fish populations in European temperate lowland rivers. Recent river restoration projects have had variable success in effectively restoring these fish populations. Knowledge on nursery habitat requirements is considered essential for effective population restoration. However, a detailed understanding of the role of habitat heterogeneity in young-of-the-year (YOY) fish population development is limited. Therefore, we carried out a synthesis of the available knowledge on nursery habitat requirements of rheophilic fish species found in European temperate lowland rivers (<200 m elevation). From a total of 603 papers, 77 studies with primary information were selected, containing 390 associations between habitat features and YOY fish. As expected, most studies focused on static components of physical riparian habitat. Generally, YOY fish require habitats of shallow depth (<0.5 m), with slow-flowing water (<0.2 m/s), gentle bank slope (<20°), variety in substratum types (fine sand to gravel), relatively warm water and high food availability. Surprisingly, no clear ontogenetic habitat shifts between larvae and juveniles were found, which may be explained by the limited spatial–temporal resolution of most studies. Since 2011, studies on habitat heterogeneity have increased, but few have explicitly assessed its role in relation to movement patterns of YOY fish for nursery success. Therefore, we recommend that future research focuses on fish movement patterns between habitat patches in heterogeneous (river-floodplain) environments, to increase the knowledge base for effective recovery of rheophilic fish populations. 相似文献
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van Gerwe TJ 《Tijdschrift voor diergeneeskunde》2012,137(3):172-176
Campylobacteriosis is a prevalent diarrhoeal illness in humans, and poultry meat is considered the most important source of foodborne infection with Campylobacter spp. In this review, the disease burden of campylobacteriosis, the most important risk factors for Campylobacter colonization in broilers, and potential interventions to reduce poultry-related human exposure to Campylobacter spp. are discussed. 相似文献
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A considerable fraction of the poultry carcasses becomes contaminated with Campylobacter by cross-contamination from the digestive tract of colonized broilers at slaughter. Campylobacter in the crop may serve as a possible source of cross-contamination, because the crop may contain high numbers of Campylobacter and is more likely to rupture during the slaughtering process than intestines. In this study, the correlation between Campylobacter colonization levels in crop and cecum was assessed in 48 broilers of 31 days of age. In addition, the effect of drinking water supplemented with 0.2% volatile fatty acid (VFA) on these Campylobacter colonization levels was studied. No correlation between crop and cecal colonization levels was found (p = 0.09; P = 0.71), indicating that future studies on cross-contamination should include an examination of not only cecal colonization levels but also crop colonization levels. Supplementation of drinking water with VFA did not result in a significant reduction of colonization levels in either the crop (P = 0.50) or the ceca (P = 0.92), indicating that this is not an effective measure to reduce cross-contamination at slaughter. 相似文献
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