Search results for "ravinto"
showing 10 items of 194 documents
Simulated eutrophication and browning alters zooplankton nutritional quality and determines juvenile fish growth and survival
2018
Source at https://doi.org/10.1002/ece3.3832. The first few months of life is the most vulnerable period for fish and their optimal hatching time with zooplankton prey is favored by natural selection. Traditionally, however, prey abundance (i.e., zooplankton density) has been considered important, whereas prey nutritional composition has been largely neglected in natural settings. High‐quality zooplankton, rich in both essential amino acids (EAAs) and fatty acids (FAs), are required as starting prey to initiate development and fast juvenile growth. Prey quality is dependent on environmental conditions, and, for example, eutrophication and browning are two major factors defining primary produ…
Relationships of temperature and biodiversity with stability of natural aquatic food webs
2023
Temperature and biodiversity changes occur in concert, but their joint effects on ecological stability of natural food webs are unknown. Here, we assess these relationships in 19 planktonic food webs. We estimate stability as structural stability (using the volume contraction rate) and temporal stability (using the temporal variation of species abundances). Warmer temperatures were associated with lower structural and temporal stability, while biodiversity had no consistent effects on either stability property. While species richness was associated with lower structural stability and higher temporal stability, Simpson diversity was associated with higher temporal stability. The responses of…
A New Method to Reconstruct Quantitative Food Webs and Nutrient Flows from Isotope Tracer Addition Experiments
2020
Understanding how nutrients flow through food webs is central in ecosystem ecology. Tracer addition experiments are powerful tools to reconstruct nutrient flows by adding an isotopically enriched element into an ecosystem and tracking its fate through time. Historically, the design and analysis of tracer studies have varied widely, ranging from descriptive studies to modeling approaches of varying complexity. Increasingly, isotope tracer data are being used to compare ecosystems and analyze experimental manipulations. Currently, a formal statistical framework for analyzing such experiments is lacking, making it impossible to calculate the estimation errors associated with the model fit, the…
The effects of an 8-year individualised lifestyle intervention on food consumption and nutrient intake from childhood to adolescence: the PANIC Study.
2021
Abstract We aimed to investigate the effects of a long-term, individualised, family-based lifestyle intervention on food consumption and nutrient intake from childhood to adolescence. We conducted an 8-year diet and physical activity intervention study in a population sample of children aged 7–9 years at baseline in 2007–2009. We allocated the participants to the intervention group (n 306) and the control group (n 198). We assessed diet by 4-d food records at baseline, 2-year follow-up and 8-year follow-up. We analysed the data using linear mixed-effects models adjusted for age at baseline and sex. The consumption of vegetables and vegetable oil-based spreads (fat ≥60 %) increased in the in…
Evidence for protein leverage in a general population sample of children and adolescents
2023
Background/ObjectivesThe strong regulation of protein intake can lead to overconsumption of total energy on diets with a low proportion of energy from protein, a process referred to as protein leverage. The protein leverage hypothesis posits that protein leverage explains variation in energy intake and potentially obesity in ecological settings. Here, we tested for protein leverage and the protein leverage hypothesis in children and adolescents.Subjects/MethodsA population sample of children, mean (SD) age 7.6 (0.4) years (n = 422), followed up at age 9.8 (0.4) years (n = 387) and at age 15.8 (0.4) years (n = 229), participating for the Physical Activity and Nutrition in Children (PANIC) st…
Maajoukkuetason kestävyysurheilijoiden ravintoanalyysi yleisurheilussa
2003
Optimaalisella ruokavaliolla voidaan vaikuttaa urheilijan suorituskykyyn sekä suorituksesta palautumiseen.Riittävän kokonaisenergiansaannin lisäksi on varmistettava riittävä hiilihydraattien, proteiiniensekä mikroravintoaineiden saanti. Lisäenergiantarpeen täyttämisen tulisi tapahtua etupäässähiilihydraattipitoisia ruoka-aineita nauttimalla. (American College of Sports Medicine ym., 2000;Hawley ym., 1995.) Tämän tutkimuksen tarkoituksena on selvittää yleisurheilun maajoukkuetasonkestävyysurheilijoiden ravintotottumuksia ruokapäiväkirjan avulla sekä päivittäisen kokonaisenergianja ravintoaineiden saannin suhdetta arvioituun energiankulutukseen sekä harjoittelu- ja suorituskykymuuttujiinviide…
Energiansaanti ja ravitsemukselliset erityispiirteet eri urheilulajeissa ja kuntoilussa
2013
Ravitsemuksella on suuri rooli ihmisen kokonaisvaltaisessa hyvinvoinnissa. Urheilijoille ruokavalio on jaksamisen, palautumisen, kehittymisen ja suorituskyvyn kannalta tärkeää. Eri urheilulajeissa on erilaisia vaatimuksia ravintoaineiden määrän ja niiden jakautumisen suhteen. Tämän tutkimuksen tarkoituksena oli selvittää eri urheilulajien edustajien ja kuntoilijoiden ravinnon saantia sekä vertailla niitä keskenään. Menetelmät. Koehenkilöinä oli 29 urheilijaa (hiihtäjät, teholajien urheilijat ja uimarit) ja 32 kuntoilijaa (ikä 17–37), joiden ravitsemustottumuksia selvitettiin ruokapäiväkirjojen avulla. Ruokapäiväkirjat analysoitiin Nutriflow-, Nutrica- ja AivoDiet -ohjelmilla. Saatuja tuloks…
Marine food web perspective to fisheries-induced evolution
2021
Fisheries exploitation can cause genetic changes in heritable traits of targeted stocks. The direction of selective pressure forced by harvest acts typically in reverse to natural selection and selects for explicit life-histories, usually for younger and smaller spawners with deprived spawning potential. While the consequences that such selection might have on the populational dynamics of a single species are well emphasised, we are just beginning to perceive the variety and severity of its propagating effects within the entire marine food webs and ecosystems. Here, we highlight the potential pathways in which fishing-induced evolution, driven by size-selective fishing, might resonate throu…
Lowered nutritional quality of prey decrease the growth and biomolecule content of rainbow trout fry
2022
Diet quality is crucial for the development of offspring. Here, we examined how the nutritional quality of prey affects somatic growth and the lipid, carbohydrate, protein, amino acid, and polyunsaturated fatty acid content of rainbow trout (Oncorhynchus mykiss) fry using a three-trophic-level experimental setup. Diets differed especially in their content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are physiologically essential polyunsaturated fatty acids for a fish fry. Trout were fed with an artificial diet (fish feed, DHA-rich), marine zooplankton diet (krill/Mysis, DHA-rich), or freshwater zooplankton diet (Daphnia, Cladocera, DHA-deficient). The Daphnia were gr…
Eutrophication reduces the nutritional value of phytoplankton in boreal lakes
2019
Eutrophication (as an increase in total phosphorus [TP]) increases harmful algal blooms and reduces the proportion of high-quality phytoplankton in seston and the content of ω-3 long-chain polyunsaturated fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) in fish. However, it is not well-known how eutrophication affects the overall nutritional value of phytoplankton. Therefore, we studied the impact of eutrophication on the production (as concentration; μg L−1) and content (μg mg C−1) of amino acids, EPA, DHA, and sterols, i.e., the nutritional value of phytoplankton in 107 boreal lakes. The lakes were categorized in seven TP concentration categories ranging from ultra…