Sökning: "food web"

Visar resultat 16 - 20 av 175 avhandlingar innehållade orden food web.

1. 16. Benthic invertebrate food webs in the Baltic Sea : Anthropogenic pressure effects and methodological advancements

   Författare :Julie Garrison; Francisco Nascimento; Ángel Borja; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; food web; trophic network; detritivore; Baltic Sea; macrofauna; marinbiologi; Marine Biology;

   Sammanfattning : Trophic interactions are ecologically important, as they structure communities, and globally important for the ecosystem functions that they facilitate. Anthropogenic pressures are altering the structure of food webs, their stability, and resilience to change. LÄS MER

3. 17. Dietary and metabolic effects of a 2-year lifestyle intervention in overweight and obese children

   Författare :Maria Waling; Christel Larsson; Marie Löf; Umeå universitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Domestic science and nutrition; Hushålls- och kostvetenskap; Kostvetenskap; Food and Nutrition;

   Sammanfattning : Background Childhood overweight and obesity have increased during the past decades and there is a need for effective intervention programs both for treatment and prevention to interrupt the increased trend. Overweight and obesity result from a combination of genetic predisposition and lifestyle where an imbalance in energy intake (EI) and total energy expenditure (TEE) is the key factor. LÄS MER

4. 18. Promoting physical activity among overweight and obese children : Effects of a family-based lifestyle intervention on physical activity and metabolic markers

   Författare :Catharina Bäcklund; Christel Larsson; Gunnevi Sundelin; Agneta Ståhle; Umeå universitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; intervention: children: overweight: obestiy: physical activity; Domestic science and nutrition; Hushålls- och kostvetenskap; Physiotherapy; Sjukgymnastik fysioterapi; sjukgymnastik; Physiotherapy; Kostvetenskap; Food and Nutrition;

   Sammanfattning : Background Overweight and obesity in childhood is associated with physical, psychological and social consequences. Physical inactivity is regarded as one of the main factors that have contributed to the increase in childhood obesity through out the world. LÄS MER

5. 19. Food web structures and carbon transfer efficiencies in a brackish water ecosystem

   Författare :Kristin Dahlgren; Ulf Båmstedt; Agneta Andersson; Marja Koski; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon transfer efficiency; Food web efficiency; zooplankton; production; pelagic; benthic; fatty acids; wax esters; Marine ecology; Marin ekologi;

   Sammanfattning : Two differently structured food webs can be distinguished in the pelagic habitat of aquatic systems; the classical one (autotrophic) with phytoplankton as a base and the microbial food web (heterotrophic) with bacteria as a base. Energy (produced at the basal trophic level) reaches higher trophic levels, i.e. LÄS MER

7. 20. Uptake Processes of Polychlorinated Biphenyls at the Base of the Pelagic Food Web

   Författare :Anna Sobek; Örjan Gustafsson; Derek Muir; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PCBs; plankton; equilibrium partitioning; uptake; aquatic food web; Environmental chemistry; Miljökemi;

   Sammanfattning : Hydrophobic organic contaminants (HOCs) are persistent, toxic to biota and are known to bioaccumulate in food webs. In this thesis, polychlorinated biphenyls (PCBs) were used as model compounds to study the fate and transport of HOCs in the aquatic environment. LÄS MER