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Carotenoids in the egg yolks of birds are considered to be important antioxidants and immune stimulants during the rapid growth of embryos. Yolk carotenoid composition is strongly affected by the carotenoid composition of the female??s diet at the time of egg formation. Spatial and temporal differences in carotenoid availability may thus be reflected in yolk concentrations. To assess whether yolk carotenoid concentrations or carotenoid profiles show any large-scale geographical trends or differences among habitats, we collected yolk samples from 16 European populations of the pied flycatcher, Ficedula hypoleuca. We found that the concentrations and proportions of lutein and some other xanthophylls in the egg yolks decreased from Central Europe northwards. The most southern population (which is also the one found at the highest altitude) also showed relatively low carotenoid levels. Concentrations of ??-carotene and zeaxanthin did not show any obvious geographical gradients. Egg yolks also contained proportionally more lutein and other xanthophylls in deciduous than in mixed or coniferous habitats. We suggest that latitudinal gradients in lutein and xanthophylls reflect the lower availability of lutein-rich food items in the northern F. hypoleuca populations and in montane southern populations, which start egg-laying earlier relative to tree phenology than the Central European populations. Similarly, among-habitat variation is likely to reflect the better availability of lutein-rich food in deciduous forests. Our study is the first to indicate that the concentration and profile of yolk carotenoids may show large-scale spatial variation among populations in different parts of the species?? geographical range. Further studies are needed to test the fitness effects of this geographical variation.  相似文献   
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Evidence from a number of avian studies suggests that limitation of exogenous calcium (Ca) may reduce egg quality and retard nestling growth. However, it is poorly understood whether reduction in chick growth in Ca-poor areas is due to insufficient intake of dietary Ca or caused by maternal Ca limitation mediated through subtle changes in composition of eggs. In this study, we provide new evidence that Ca availability during egg formation may indeed affect egg composition and influence chick development of the great tit Parus major at early developmental stages. Ca-supplemented birds breeding in base-poor pine forests produced eggs with elevated yolk Ca concentration compared with controls, while no such effect of supplementation was detected in case of eggshell thickness. Nestling tarsus length in the first half of the nestling period was positively influenced by both yolk dry mass and yolk Ca concentration. The effect of supplementary Ca did not persist throughout the nestling period; initial effects of egg components disappeared as nestlings aged. We conclude that apparently normal eggs may harbor poor nutrient and mineral conditions for chick growth. Such subtle changes in composition of eggs can depress chick growth, especially in harsh years.  相似文献   
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In birds, it has been shown that reproductive effort may impair parental condition, while the relation of different condition indices to subsequent survival is still poorly understood. In this study, we measured body mass and various hematological condition indices in breeding great tits in relation to local survival. Number and quality of nestlings and the occurrence of second broods, potentially reflecting parents' breeding effort, were also considered in analyses. The great tits, both male and female, that returned the following year had had a higher albumin/globulin ratio, lower plasma globulin concentration, and a lower heterophile/lymphocyte ratio during breeding in the preceding year, compared to those who did not return. Surviving males (but not females) also had had a higher level of circulating lymphocytes, compared to nonsurvivors. There was no correlation between breeding effort and survival. We conclude that better immunological state and lower stress in great tits during breeding were positively related to their survival probability.  相似文献   
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Vallo  V.  Remund  U.  Boller  E. F. 《BioControl》1976,21(3):251-256
The authors, members of the IOBC working group on genetic control of the European cherry fruit flyRhagoletis cerasi L., present the summarized results of a joint 4-year experiment aiming at the optimalization of storage conditions for stockpiled pupae. Highest emergence rates are achieved by chilling periods of 5 to 6 months and recommended storage temperatures are close to the developmental threshold of +5°C. Total storage time of pupae should not exceed 14 months.
Résumé Les auteurs, membres du groupe de travail de l'O.I.L.B. sur la lutte génétique contre la mouche européene de la cerise,Rhagoletis cerasi L., présentent le bilan de 4 ans d'expérimentation en commun en vue de trouver la meilleure méthode de conservation des pupes. Les taux d'émergence imaginale les plus élevés sont obtenus à la suite d'une période de froid de 5 à 6 mois à une température voisine du seuil de développement: 5°C. La durée totale de la conservation au froid des pupes ne doit pas dépasser 14 mois.


Fourth report of the IOBC working group on genetic control ofR. cerasi.  相似文献   
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Phenological events such as conception or parturition dates may have profound impact on several key life-history traits of ungulates at the individual as well as the population level. However, relatively little is known about the causes of variation in the timing of reproduction. Based on a 17-year survey of reproductive tracts, we investigated the effect of climate, population density, and age on the conception date of female moose (Alces alces) harvested in Estonia. Ninety-five percent of studied moose cows were conceived within a period of 9 weeks (29 August–30 October), while more than 45 % of all moose cows were conceived from 19 September to 2 October. Conception date was negatively related to population density and nonlinearly to the regional measure of winter climate reflecting the maximal extent of ice on the Baltic Sea (MIE) in the previous winter. High air temperatures during rut (in September) delayed the conception date. The timing of conception also depended on female age. Yearlings conceived significantly later as compared to females of all other age groups. Our findings corroborate the importance of density-dependent as well density-independent processes on the timing of conception of this ungulate. We also propose that the effect of population density on conception date may be mediated by increasing ecological carrying capacity concurrent with increasing population abundance.  相似文献   
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The authors — members of the OILB working group on genetic control of the Europan cherry fruit fly,Rhagoletis cerasi L. — describe in this second report the development of a standard trap for the target species and its applications in the framework of the genetic control procedures in progress. The trap has increased the attractiveness for the flies about 100 times compared with the traditional bait traps and has proven its effectiveness in recent suppression programs in the field.
Résumé Les auteurs, membres du groupe de travail OILB sur la lutte génétique contre la mouche européenne des cerises,R. cerasi, décrivent la mise au point d'un piège standard pour l'espèce considérée et ses applications dans le cadre des investigations en cours sur la lutte génétique contre ce ravageur. Ce piège est cent fois plus attractif que les pièges traditionnels et a prouvé son efficacité dans les récentes études conduites sur le terrain.


Second report of the OILB working group on genetic control ofR. cerasi.  相似文献   
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