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Visar resultat 21 - 25 av 348 avhandlingar som matchar ovanstående sökkriterier.

1. 21. Effects of Great Cormorant Predation on Fish Populations and Fishery

   Författare :Henri Engström; Sture Hansson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Great Cormorant; Phalacrocorax carbo sinensis; predation; population regulation; diet; diet preferences; eel; behavioural responses; bird-fishery conflicts; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

   Sammanfattning : The strong increase in number of Great cormorants Phalacrocorax carbo in Sweden in recent years has led to conflicts - particularly with fishery. This thesis focuses on the possible effects of cormorant predation on fish populations. LÄS MER

3. 22. Life history decisions in a changing environment : A long-term study of a temperate barnacle goose population

   Författare :Henk van der Jeugd; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Age at first reproduction; Barnacle goose; Branta leucopsis; Coloniality; Dispersal; Life-history; Mate choice; Population dynamics; Survival; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; Animal Ecology; zooekologi;

   Sammanfattning : This thesis shows that climate and increasing population density have profound effects on survival, age at first reproduction, and natal dispersal in a rapidly increasing temperate barnacle goose Branta leucopsis population on Gotland, Sweden.Colony size was found to be the most important fitness-determinant because of strong density-dependent effects on reproduction. LÄS MER

4. 23. Prodromal Cognitive Signs of Dementia

   Författare :Simona Sacuiu; Göteborgs universitet; []
   Nyckelord :cognitive function; mild cognitive impairment; prediction of dementia; Alzheimer s disease; vascular dementia; population study; birth cohort trends; terminal decline;

   Sammanfattning : The increase in proportion of elderly worldwide, coupled with the fact that increasing age is a primary risk factor for dementia, have fuelled the efforts to unveil the warning signs of dementia. Although important achievements have been made in this field during the last decades, many questions are still to be answered. LÄS MER

5. 24. Studying ageing: experiences, description, variation, prediction and explanation

   Författare :Bo G. Eriksson; Göteborgs universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Sociology; Gerontology; Demography; Longevity; Health promotion; Social facts; Sense of cohesion; Population; Random sample.;

   Sammanfattning : The study follows a line of experiences, description, variation, prediction and explanation concerning ageing, health promotion and longevity. The experiences of aging were acquired during my studies of conversations, participation in longitudinal population studies in Gothenburg, and working with the Centre for Development of Home help services. LÄS MER

7. 25. Birth cohort differences in cognitive aging: Secular trends in cognitive functioning and decline over 30 years in three population-based Swedish samples

   Författare :Peter Karlsson; Göteborgs universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Aging; cardiovascular risk factors; cognitive decline; cohort differences; fluid and crystallized abilities; Flynn effect; longitudinal;

   Sammanfattning : The overarching aim of this thesis was to investigate birth cohort differences in level of cognitive functioning and change in later life in three population-based representative samples drawn from the Gerontological and Geriatric Population Studies in Gothenburg (H70), Sweden. We used data from cohorts, born in 1901-02, 1906-07, and 1930, measured at ages 70, 75, and 79 on the same cognitive measures. LÄS MER