Sökning: "food web structure"

Visar resultat 11 - 15 av 56 avhandlingar innehållade orden food web structure.

1. 11. The significance of species groups for food web structure and functioning

   Författare :Mikael Ohlsson; Anna Eklöf; György Barabas; Louis-Félix Bersier; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : In ecosystems across the world, species co-exist, compete, and consume, all while adapting to environmental conditions and disruptions. An important key to the puzzle of understanding how species will respond to changes in the ecosystems, caused by for example climate change, pollution, habitat destruction, and overexploitation, is what current roles species have in a larger context. LÄS MER

3. 12. Direct and indirect effects of fish predation and excretion in aquatic food webs

   Författare :José Luiz Attayde; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; Hydrobiology; zooplankton; resilience; predation; phytoplankton; nutrient enrichment; nutrient recycling; interaction strength; herbivory; food webs; food chain; excretion; fish; detritus; detritivory; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

   Sammanfattning : The aim of this thesis was to elucidate the mechanisms by which planktivorous fish can affect planktonic communities in lakes and how they may affect benthic communities through their effects on planktonic communities. In a laboratory experiment, nutrients released by fish increased algal biomass and altered phytoplankton community structure, suggesting that fish can affect phytoplankton by directly releasing nutrients. LÄS MER

4. 13. The role of allelopathy in microbial food webs

   Författare :Astrid Weissbach; Catherine Legrand; Ellen Van Donk; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Microbial food web; Allelopathy; Alexandrium tamarense; Prymnesium parvum; Infochemicals; marine plankton community; Freshwater ecology; Limnisk ekologi; Akvatisk ekologi; Aquatic Ecology;

   Sammanfattning : Phytoplankton produce allelochemicals; excreted chemical substances that are affecting other microorganisms in their direct environment.In my thesis, I investigated strain specific variability in the expression of allelochemicals of the harmful flagellate Prymnesium parvum, that is euryhaline but mainly bloom forming in brackish water. LÄS MER

5. 14. Functionality of Spray-Dried Whey Protein Powders - Surface Composition, Particle Morphology and Rehydration

   Författare :Ida-Marie Andersson; Avdelningen för livsmedel och läkemedel; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Milk serum protein; Lactose; Whey protein powders; Spray drying; Particle morphology; Surface composition; Rehydration; Functionality; Milk serum protein; Lactose; Whey protein powders; Spray drying; Particle morphology; Surface composition; Rehydration; Functionality;

   Sammanfattning : Whey protein powder functionality is expected to be closely linked to both structure and properties of the proteins. It is essential that whey protein powders are easily dispersed and dissolved in order to fulfil the specified nutrient content and the functionality in the final product. LÄS MER

7. 15. Food Service and Nutritional Care in Swedish Elderly Care : The Progress of National Actions and their Local Interpretations

   Författare :Malin Skinnars Josefsson; Ylva Mattsson Sydner; Margaretha Nydahl; Anne Marie Beck; Uppsala universitet; []
   Nyckelord :food service; nutritional care; elderly care; national actions; municipality; questionnaire; registry data; Kostvetenskap; Food; Nutrition and Dietetics;

   Sammanfattning : The main aim of this thesis is to study local level outcomes regarding food service and nutritional care in Swedish elderly care in relation to the progress of national actions. Study I compared results from a repeated national survey using a questionnaire investigating the general structure and organisation of food service in elderly care. LÄS MER