Search results for " web"

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…

Data from: The importance of phytoplankton biomolecule availability for secondary production

2018

The growth and reproduction of animals is affected by their access to resources. In aquatic ecosystems, the availability of essential biomolecules for filter-feeding zooplankton depends greatly on phytoplankton. Here, we analyzed the biochemical composition, i.e., the fatty acid, sterol and amino acid profiles and concentrations as well as protein, carbon, nitrogen, and phosphorus content of 17 phytoplankton monocultures representing the seven most abundant phytoplankton classes in boreal and sub-arctic lakes. To examine how the differences in the biochemical composition between phytoplankton classes affect their nutritional quality for consumers, we assessed the performance of Daphnia, on …

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…

Taming big knowledge evolution

2016

Information and its derived knowledge are not static. Instead, information is changing over time and our understanding of it evolves with our ability and willingness to consume the information. When compared to humans, current computer systems seem very limited in their ability to really understand the meaning of things. On the other hand, they are very powerful when it comes down to performing exact computations. One aspect which sets humans apart from machines when trying to understand the world is that we will often make mistakes, forget information, or choose what to focus on. To put this in another perspective, it seems like humans can behave somehow more randomly and still outperform …

Introduzione

2015

Il saggio, a carattere introduttivo, descrive come gli studi di genere abbiano attraversato trasversalmente i temi della sociologia, fino ad articolarne le categorie che oggi identificano le nuove tecnologie della comunicazione, nella auto ed etero costruzione del sé.

Il geodatabase dell'Herbarium Mediterraneum Panormitanum [PAL] per la mappatura di dati primari sulla biodiversità

2010

Controlling factors of phytoplankton assemblages in wetlands: an experimental approach

2003

The aim of this work is to answer some questions like: what factors control the phytoplankton assemblage? What factor or factors are perturbing the assemblage? What factors are driving or maintaining the stability? Are the different responses to the control factors dependent on the hierarchy level? For that, we tested experimentally the influence of herbivory, planktivory, nutrients and sediment on phytoplankton assemblages and its stability from a hypertrophic wetland (Las Tablas de Daimiel National Park, Spain) in three microcosm experiments. The study of the steady state phytoplankton assemblages in this perturbed system could point out some underlying processes instead of competition. T…

Another New Riparian Dendrobatid Frog Species from the Upper Amazon Basin of Peru

2003

A new dendrobatid frog of the genus Colostethus is described from the Cordillera El Sira, an isolated mountain ridge in the upper Amazon basin of central Peru. It has bright yellowish dorsolateral stripes thus resembling Colostethus exasperatus, Colostethus sp. (cf. exasperatus), and Colostethus nexipus, all from the upper Amazon basin of Ecuador and Peru. In morphology, the new species is most similar to Colostethus mcdiarmidi from the eastern Andean slopes of Bolivia and Colostethus alessandroi from the eastern Andean slopes of Peru. The new species can be distinguished from all these taxa on the basis of coloration including the color of the ring around pupil in life, adult male size, le…

Trophic cascades in benthic marine ecosystems: lessons for fisheries and protected-area management

2000

An important principle of environmental science is that changes in single components of systems are likely to have consequences elsewhere in the same systems. In the sea, food web data are one of the few foundations for predicting such indirect effects, whether of fishery exploitation or following recovery in marine protected areas (MPAs). We review the available literature on one type of indirect interaction in benthic marine ecosystems, namely trophic cascades, which involve three or more trophic levels connected by predation. Because many indirect effects have been revealed through fishery exploitation, in some cases we include humans as trophic levels. Our purpose is to establish how wi…

Use of algae in active biomonitoring of Surface waters

2014

Przeprowadzono badania biomonitoringowe trzech zbiorników retencyjnych położonych na terenie województwa opolskiego (południowa Polska): Zbiornika Turawa, Zbiornika Nysa i Zbiornika Otmuchów. W glonach słodkowodnych Spirogyra sp. i morskich Palmaria palmata (Linnaeus) Weber & Mohr, eksponowanych w badanych wodach, oznaczono metodą absorpcyjnej spektrometrii atomowej (AAS) przyrosty stężeń: Mn, Fe, Cu, Zn, Cd i Pb. W wodach oznaczano także pH, konduktywność oraz stężenie Mn i Fe. Stężenia Cu, Zn, Cd i Pb w badanych wodach były mniejsze od granicy oznaczalności metody. Badania prowadzono od czerwca do lipca 2014 r. Wskazano na różnice w przyrostach stężeń metali ciężkich w próbkach glonów eks…