Search results for "ravinto"

Diet estimation and comparison of fatty acid-based diet modelling methods

2019

Trophic interactions have been a popular research subject among ecologists for decades because understanding the structure of food webs is essential in understanding consumer-resource interactions and complex ecosystems. Consumer diet estimation with biological tracer-based mixing models is an important and recently rapidly developing tool for deciphering aquatic food webs. Bayesian frameworks have been introduced to estimate diets accurately with stable isotope proportions. The low quantity of different stable isotope tracers, however, limits greatly the diet estimation accuracy of complex consumer diets. Therefore, fatty acids have been used as biological tracers to multiply the quantity …

Understanding and Controlling Food Protein Structure and Function in Foods: Perspectives from Experiments and Computer Simulations

2020

The structure and interactions of proteins play a critical role in determining the quality attributes of many foods, beverages, and pharmaceutical products. Incorporating a multiscale understanding of the structure–function relationships of proteins can provide greater insight into, and control of, the relevant processes at play. Combining data from experimental measurements, human sensory panels, and computer simulations through machine learning allows the construction of statistical models relating nanoscale properties of proteins to the physicochemical properties, physiological outcomes, and tastes of foods. This review highlights several examples of advanced computer simulations at mol…

Blackfly Larvae (Simulium spp.) Can Intensify Methylmercury Biomagnification in Boreal Food Webs

2020

AbstractGlobal pollution of mercury (Hg) threatens ecosystem and human health. We measured total Hg (THg) and monomethylmercury (MMHg) concentrations in filter-feeding blackfly (Simulium spp.) larvae in the inflows and the outflows of six boreal lakes with no Hg point source pollution. THg in the larvae ranged from 0.03 to 0.31 mg kg−1 dw and MMHg between 0.02 and 0.25 mg kg−1 dw. The proportion of MMHg in the larvae was 74 ± 0.16% and ranged from 43 to 98% of THg, the highest proportions being comparable to those typically found in aquatic predatory insects and fish. We compared the larvae MMHg concentrations to river water quality, catchment land-use, and to size-adjusted lake pike THg da…

Filtration of Nordic recirculating aquaculture system wastewater : Effects on microalgal growth, nutrient removal, and nutritional value

2021

Microalgal bioremediation of recirculating aquaculture system (RAS) wastewater represents an alternative for wastewater treatment with the potential to generate valuable biomass. This study evaluated the effects of removing biological contamination and suspended solids from Nordic area RAS wastewater through filtration with 0.45 μm filters on the performance and nutritional value of microalgae. All three tested green microalgae (Haematococcus pluvialis, Monoraphidium griffithii, and Selenastrum sp.) were able to grow in raw (unfiltered) and filtered RAS wastewater. Cultivation in raw RAS wastewater decreased the ω-3 and ω-6 fatty acid content of H. pluvialis as compared to filtered wastewat…

Ventovieraana Verkkokalastajatorpassa : kulttuurifilosofinen vuoropuhelu

2017

The importance of environmental microbes for Drosophila melanogaster during seasonal macronutrient variability

2021

AbstractExperiments manipulating the nutritional environment and the associated microbiome of animals have demonstrated their importance for key fitness components. However, there is little information on how macronutrient composition and bacterial communities in natural food sources vary across seasons in nature and on how these factors affect the fitness components of insects. In this study, diet samples from an orchard compost heap, which is a natural habitat for many Drosophila species and other arthropods, were collected over 9 months covering all seasons in a temperate climate. We developed D. melanogaster on diet samples and investigated stress resistance and life-history traits as w…

Intressikamppailua alkoholikentällä : karaokekysymyksen yhteiskuntapoliittiset diskurssit

2008

Tämän pro gradu -tutkielman aiheena on alkoholihallinnon ja ravintolaelinkeinon välinen anniskelun jatkoaikoihin liittyvä intressikamppailutilanne. Tutkielmassa tarkastellaan sitä, miten alkoholihallinnon ja ravintolaelinkeinon välinen intressikamppailutilanne (karaokekysymys) on rakentunut, millaisia diskursseja sen taustalla on sekä miten diskurssit vaikuttavat alkoholikentän toimintaan. Kysymyksiin pureudutaan tutkimalla sitä, miten intressikamppailutilannetta kuvataan, millaiset puhetavat rakentavat, pitävät yllä tai pyrkivät muuttamaan intressikamppailutilannetta sekä millaisia seurauksia diskursseilla on. Tutkimuksen tavoitteena on tuottaa uutta tietoa alkoholikentän rakenteesta ja to…

The second life of terrestrial and plastic carbon as nutritionally valuable food for aquatic consumers

2023

Primary production is the basis for energy and biomolecule flow in food webs. Nutritional importance of terrestrial and plastic carbon via mixotrophic algae to upper trophic level is poorly studied. We explored this question by analysing the contribution of osmo- and phagomixotrophic species in boreal lakes and used 13C-labelled materials and compound-specific isotopes to determine biochemical fate of carbon backbone of leaves, lignin–hemicellulose and polystyrene at four-trophic level experiment. Microbes prepared similar amounts of amino acids from leaves and lignin, but four times more membrane lipids from lignin than leaves, and much less from polystyrene. Mixotrophic algae (Cryptomonas…

Fish Diets in Aquaponics

2019

AbstractFish and feed waste provide most of the nutrients required by the plants in aquaponics if the optimum ratio between daily fish feed inputs and the plant growing area is sustained. Thus, the fish feed needs to fulfil both the fish’s and plant’s nutritional requirements in an aquaponic system. A controlled fish waste production strategy where the nitrogen, phosphorus and mineral contents of fish diets are manipulated and used provides a way of influencing the rates of accumulation of nutrients, thereby reducing the need for the additional supplementation of nutrients. To optimize the performance and cost-effectiveness of aquaponic production, fish diets and feeding schedules should be…

Ecology and extent of freshwater browning - What we know and what should be studied next in the context of global change

2022

Water browning or brownification refers to increasing water color, often related to increasing dissolved organic matter (DOM) and carbon (DOC) content in freshwaters. Browning has been recognized as a significant physicochemical phenomenon altering boreal lakes, but our understanding of its ecological consequences in different freshwater habitats and regions is limited. Here, we review the consequences of browning on different freshwater habitats, food webs and aquatic-terrestrial habitat coupling. We examine global trends of browning and DOM/DOC, and the use of remote sensing as a tool to investigate browning from local to global scales. Studies have focused on lakes and rivers while seldo…