黑河下游河岸绿洲区包气带土壤水分与植被生长状况的研究

黑河下游荒漠平原区近年来由于河水流入量的持续减小,致使依赖河水补给来源的地下水呈减少趋势,造成区域性地下水位下降,从而引起一系列生态环境问题。通过研究黑河下游河岸绿洲区非饱和带的含水量、地下潜水埋深、土壤类型结构等与河岸绿洲植被生长状况之间的关系,发现土壤结构、地下水位埋深和土壤盐分是决定研究区植被生长状况的3个主要因素,而土壤结构是不可改变的,土壤盐分又与地下水关系密切,因此,地下水是极端干旱区植被生长状况的决定因素。     

病毒抗原糖基化与免疫关系的研究进展

糖基化是蛋白质的一种重要的翻译后修饰,在影响蛋白质的结构和功能方面扮演着重要角色。许多病毒抗原都有糖基化的现象,糖基化会改变病毒对宿主的免疫逃避、病毒抗原的免疫原性等。了解病毒抗原糖基化与免疫之间的关系,将有助于抗病毒疫苗的研究。     

Physiological status of Drosophila suzukii (Diptera: Drosophilidae) affects their response to attractive odours

An improved understanding of the biology of the invasive pest, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is critical for the development of effective management strategies. Trapping is one technique used for both detection and control; however, the efficacy of trapping can vary depending on the target insect's physiological state, its behavioural priorities and the type of attractant used in the trap. We conducted a series of caged trapping experiments and a greenhouse trapping experiment to investigate the effects of D. suzukii feeding status, age, mating status, ovipositional status and seasonal morph type on the capture rate of traps baited with fermentation odours. Starved flies were trapped at greater rates compared to fed flies; more virgin flies were trapped than mated flies; flies deprived of an oviposition substrate were trapped more frequently than flies given an oviposition substrate. It is still unclear whether age or seasonal morphology affect bait response. Lastly, a caged choice experiment investigated the relationship between female reproductive status and attraction to fermentation or fruit odours. Fermentation‐based traps captured female flies regardless of their reproductive status but, ripe fruit‐based traps were more attractive to flies with more than seven eggs. In summary, studies that use fermentation‐based traps should recognize that capture rates of D. suzukii will depend on the feeding, mating and oviposition experiences of the population; also, fruit‐based traps may better target gravid females.     

Turnover of passerine birds on islands in the Aegean Sea (Greece)

Aim We wish to determine the effect of migratory status on turnover rates in island birds. Because turnover is influenced by factors other than migratory status, we also considered the influence of body size and physical characteristics of the islands inhabited on the probabilities of extinction and immigration. Location The Mediterranean islands of Delos, Astypalea, Paros, Naxos and Lesvos in the Aegean Sea, Greece. Methods The passerine birds of these islands were surveyed between 1954 and 1961 by G.E. Watson, and were resurveyed between 1988 and 1992. The effects of migratory status and body size on the probabilities of extinction and immigration were examined by G‐tests of linear trend in proportion, and analysis of variance, respectively. A combined analysis of migratory status, body size and physical characteristics of the islands was carried out using logistic regressions of the probabilities of extinction and immigration on these factors. Results Species number on each island changed little between surveys, with no island's species number changing by more than one species. Twelve population extinctions and 11 immigrations were recorded. The smallest island, Delos (6 km²), had the highest annualized relative turnover rate (1.08), while the four larger islands (96–1614 km²) had lower and mutually similar rates (0.21–0.27). Populations on higher elevation islands were less likely to go extinct. There is no evidence for an effect of body size on the probabilities of extinction or immigration. Migratory status affected extinction and immigration probabilities differently: migratory species were more likely to immigrate, but less likely to go extinct. Main conclusions The position of the Aegean islands along a major north–south flyway may account for the observed effects of migratory status. The annual passage of large numbers of migrants may, via the rescue effect, decrease the chances of extinction, while at the same time increasing the chances of colonization of unoccupied islands. The likelihood of both extinction and immigration involves a complex interaction between life‐history traits and island characteristics. The effects of migratory status will depend not only on consideration of vagility, vulnerability and stochasticity identified by previous authors, but also upon the location of the islands in relationship to migratory pathways.     

Nitric oxide and changes of iron metabolism in exercise

Accumulated data imply that exercise itself might not lead to a true iron deficiency or 'sport anaemia' in a healthy athlete who has adequate iron intake. The higher prevalence of iron deficiency anaemia in younger female athletes might be not due to exercise itself, but probably results from dietary choices, inadequate iron intake and menstruation. These factors can also induce iron deficiency or anaemia in the general population. However, exercise does affect iron metabolism, leading to low or sub-optimal iron status. The underlying mechanism is unknown. In this review, recent advances in the study of the effect of exercise on iron metabolism and nitric oxide, and the relationship between nitric oxide and iron status in exercise are discussed. A hypothesis that increased production of nitric oxide might contribute to sub-optimal iron status in exercise is proposed.     

Sex differences in circulating antibodies in nestling Pied Flycatchers Ficedula hypoleuca

Sex differences in immune function are relatively well studied in vertebrate animals, although the patterns are not always clear in birds. The study of immune responses in nestlings of wild bird populations may constitute an appropriate way to investigate inherent intersexual differences while controlling for environmental conditions such as parasitism that affect male and female individuals growing in the same nest. We studied whether the cell‐mediated immune response, as measured by phytohaemagglutinin (PHA) injection, and the levels of circulating antibodies differ between sexes of Pied Flycatcher nestlings Ficedula hypoleuca. No sex differences in nestling cell‐mediated immune response were found, but females showed significantly higher levels of plasma immunoglobulins than males did. Although nestling birds may not have a fully functional humoral immune defence, our study indicates that sex differences in the humoral component exist at this early stage of life. Given the importance of antibodies in the fight against parasite, bacterial and viral infections, the intrinsic sex disparity in circulating antibodies may have important implications for the life history of each sex.     

Diversity in the immune system: “Preconceived ideas” or ideas preconceived?

Two concepts of the evolution and regulation of expression of the combining site repertoire of the immune system, are compared. One view is based on the Associative Recognition Theory as formulated by the author and the other is based on the Idiotype Network Idea as conceived by Jerne. The two concepts are analyzed from the point of view of their logic, internal consistency and factual support.     

The GENIPOL European flounder Platichthys flesus L. toxicogenomics microarray: application for investigation of the response to furunculosis vaccination

The GENIPOL cDNA microarray, comprising some 14 000 elements representing 3336 unique expressed sequence tag clusters, was developed for studies on pollutant chemical effects on hepatic gene expression in the sentinel flatfish species Platichthys flesus , the European flounder. This array derived from probes obtained by targeted cloning of xenobiotic metabolising and responsive genes, subtractive suppressive hybridization of pollutant-treated fish and subtracted normalized cDNA libraries of treated fish has been successfully utilized for diagnosing effects of prototypical pollutants, endocrine disruptors and analysis of environmental effects. In the latter context, it has been recommended by the International Council for Exploration of the Sea that the array is tested in European monitoring programmes for assessment of the biological effects of contaminants. Sequence homology is sufficiently great between P. flesus and other pleuronectid flatfish to enable satisfactory use with other species, including American winter flounder and Japanese flounder, plaice, Atlantic halibut and sole. Elucidation of the effects of pollutants requires knowledge of other affectors of gene expression, and in this context the observed effects of a bacterial infection have been studied. The 'infection' was experimentally applied by challenge with a vaccine containing Aeromonas salmonicida , the bacterial agent causing furunculosis in flounder and salmonids. These results show that, despite its currently limited gene coverage, application of this array is not confined to toxicology.     

Western Diet Triggers NLRP3-Dependent Innate Immune Reprogramming

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