TAILIEUCHUNG - lackwell Publishing, Ltd. Predictors of reproductive cost in female Soay sheep

The nontraditional distributor as a source of RH/FP information is being replicated in Northern Nigeria, a region that has proven particularly reluctant to use modern contraceptive methods. Local women can be hard to reach because of the tradition of Purdah, which keeps them in the home unless escorted by a male relative. But traditional beauticians (Mai Lalle) and hair stylists (Mai Kitso) have access to both young married and unmarried women. Pathfinder plans to train these women to counsel their clients on RH/FP issues, including healthy timing and spacing of pregnancies. They will distribute contraception and will refer their clients to health facilities when necessary. Mai. | Journal of Animal Ecology 2005 74 201-213 Predictors of reproductive cost in female Soay sheep G. TAVECCHIA tí T. COULSONf B. J. T. MORGANỊ J. J. C. PILKINGTON F. M. D. GULLANDH and T. H. CLUTTON-BROCKf f Department of Zoology University of Cambridge Downing Street Cambridge CB2 3EJ UK Institute of Mathematics and Statistics University of Kent Canterbury CT2 7NF UK Institute of Cell Animal and Population Biology University of Edinburgh West Mains Road Edinburgh EH9 3JT UK and The Marine Mammal Center 1065 Fort Cronkhite Sausalito CA 9496 USA Summary 1. We investigate factors influencing the trade-off between survival and reproduction in female Soay sheep Ovis aries . Multistate capture-recapture models are used to incorporate the state-specific recapture probability and to investigate the influence of age and ecological conditions on the cost of reproduction defined as the difference between survival of breeder and non-breeder ewes on a logistic scale. 2. The cost is identified as a quadratic function of age being greatest for females breeding at 1 year of age and when more than 7 years old. Costs however were only present during severe environmental conditions wet and stormy winters occurring when population density was high . 3. Winter severity and population size explain most of the variation in the probability of breeding for the first time at 1 year of life but did not affect the subsequent breeding probability. 4. The presence of a cost of reproduction was confirmed by an experiment where a subset of females was prevented from breeding in their first year of life. 5. Our results suggest that breeding decisions are quality or condition dependent. We show that the interaction between age and time has a significant effect on variation around the phenotypic trade-off function selection against weaker individuals born into cohorts that experience severe environmental conditions early in life can progressively eliminate low-quality phenotypes from these

• Sức khỏe phụ nữ
• Immunotherapies
• Vaccines
• Envelope Specific
• Antibody and Vaccine
• Vaccine Efficacy
• Cytokines and Chemokines
• comprehensive imple mentation
• stringent enforcement
• intention of regulation
• Novel Immunotherapies
• Therapeutical Responses
• Metastatic Process
• Suppressor Genes
• Human papilloma
• Cancer Pathways
• medical books
• pharmacology
• epidemiologic
• Obstetrics
• anatomy
• Preventing Morbidity
• Multidisciplinary Care
• registration methodology
• giáo trình y học
• tài liệu y học
• các tác nhân chống virus
• điều trị nhiễm virus
• bệnh viêm gan C mãn tính