Search results for "web"
showing 10 items of 2018 documents
Niveles y patrones de actividad física en sesiones de motricidad infantil basadas en el juego libre
2017
[Resumen] El objetivo del estudio consistió en analizar los niveles y patrones de actividad física de niñas y niños de educación infantil en dos sesiones de motricidad centradas en el juego libre. Participaron 32 estudiantes, de edades comprendidas entre los 48 y 54 meses y pertenecientes al segundo ciclo de educación infantil, de un colegio público de la Provincia de València, España. Los niveles y patrones de actividad física se determinaron a través de podometría y de un sistema observacional. El modelo A consistió en una sesión de juego libre por rincones-tiempo, mientras que el modelo B consistió en una sesión de juego libre por rincones-libre elección. Los resultados muestran que más …
Hiding in plain sight: observing planet-starspot crossings with the James Webb Space Telescope
2021
Transiting exoplanets orbiting active stars frequently occult starspots and faculae on the visible stellar disc. Such occultations are often rejected from spectrophotometric transits, as it is assumed they do not contain relevant information for the study of exoplanet atmopsheres. However, they can provide useful constraints to retrieve the temperature of active features and their effect on transmission spectra. We analyse the capabilities of the James Webb Space Telescope in the determination of the spectra of occulted starspots, despite its lack of optical wavelength instruments on board. Focusing on K and M spectral types, we simulate starspots with different temperatures and in differen…
Are people willing to pay for eco-labeled wild seafood? An overview
2017
In the last two decades, eco-labeled seafood has been becoming an instrument of sustainability directed towards consumers, addressing a market-based incentive for better management of fisheries. In this context, several studies across the countries have been conducted about how much consumers are willing to pay for fish caught by certifiably sustainable fishing activities. In this direction, the aim of this study was to systematize the available information about the willingness-topay (WTP) more for eco-labeled wild seafood. Therefore, only papers published on ISI journals were searched on “Web of Knowledge” and “SciVerse Scopus” platforms, using the combinations of the following key words:…
A Top-Down Approach Based on Business Patterns for Web Information Systems Design
2009
International audience; In this paper we develop an approach that is based on a top-down strategy to realization of transactional web services. Our approach highlights non-functional properties (e.g., traceability, security) which are essential to preserving an application's quality. It is implemented in three steps. The first step is a breakdown of the application in accordance with a related business involved. The goal of this step is to have sets of actors and activity patterns defined as an activity workflow that support the architecture of the application. The next step allows developing a mapping of the activity pattern on this architecture. The aim of this step is to identify the ris…
Changes in community composition determine recovery trajectories from multiple agricultural stressors in freshwater ecosystems
2020
AbstractPesticides have been identified worldwide as a threat for aquatic biodiversity due to their widespread use in agriculture and their capacity to reach freshwater ecosystems. Very little is known about the consequences of pesticide mixtures targeting different organism groups on community dynamics. Especially, how horizontal changes within one trophic level are propagated vertically across the food web has been rarely investigated. To get insight on the effects of pesticide mixtures on community dynamics, we performed a mesocosm experiment manipulating three common agricultural stressors: chlorpyrifos (an insecticide), diuron (an herbicide) and nutrients. The results of this study sho…
Pelagic food web as the basis of fisheries in Lake Tanganyika: A bioenergetic modeling analysis
2002
Fisheries in Lake Tanganyika, East Africa, are mainly based on two predominantly planktivorous clupeids (Stolothrissa tanganicae and Limnothrissa miodon) and a centropomid predator (Lates stappersi), caught with lift nets, purse seines, and beach seines by traditional, artisanal, and industrial fishers. The biological basis and sustainability of the present fisheries were assessed in a comprehensive project “Research for the Management of the Fisheries on Lake Tanganyika” in 1992–1998. Production in the whole lake was estimated for the entire pelagic food chain leading to the commercially important fish species. Preliminary calculations based on a constant production efficiency suggested th…
Regulation of decomposer community structure and decomposition processes in herbicide stressed humus soil
1997
Abstract Regulation of soil decomposer community structure and ecosystem processes, such as nutrient cycling, under herbicide stress was studied in a microcosm experiment. For the experiment, coniferous forest soil was defaunated and put into the microcosms. In the microcosms two different food webs including microbes, nematodes, tardigrades and oribatid mites, either with or without predatory mesostigmatid mites, were reconstructed. Half of the microcosms were stressed with a herbicide (active ingredient was terbuthylazine). During the 57 weeks incubation community structure of decomposers and nitrogen mineralisation were studied at five destructive samplings and two water irrigations. Soi…
Notes on Two Specimens of the Rare Swallowtail Eurytides iphitas Hübner, [1821] (Papilionidae) from the Friedrich Wilhelm Niepelt Collection in the M…
2021
Eurytides iphitas Hubner, [1821] is a rare swallowtail species endemic to southeast Brazil. Some authors believe that the species is extinct as the last live specimens were seen in 1937. During examination of the Friedrich Wilhelm Niepelt collection in the Museum of Natural History, University of Wroclaw, two specimens of this species were found. One of them has an enigmatic label “Peru Weberbauer S. G.”, which we can certainly attribute to the naturalist Otto Weberbauer, or his son August Weberbauer, the most famous pioneer of Peruvian botany.
Effects of temporal abiotic drivers on the dynamics of an allometric trophic network model
2023
Current ecological research and ecosystem management call for improved understanding of the abiotic drivers of community dynamics, including temperature effects on species interactions and biomass accumulation. Allometric trophic network (ATN) models, which simulate material (carbon) transfer in trophic networks from producers to consumers based on mass-specific metabolic rates, provide an attractive framework to study consumer–resource interactions from organisms to ecosystems. However, the developed ATN models rarely consider temporal changes in some key abiotic drivers that affect, for example, consumer metabolism and producer growth. Here, we evaluate how temporal changes in carrying ca…
Poor nutritional quality of primary producers and zooplankton driven by eutrophication is mitigated at upper trophic levels
2022
Eutrophication and rising water temperature in freshwaters may increase the total production of a lake while simultaneously reducing the nutritional quality of food web components. We evaluated how cyanobacteria blooms, driven by agricultural eutrophication (in eutrophic Lake Köyliöjärvi) or global warming (in mesotrophic Lake Pyhäjärvi), influence the biomass and structure of phytoplankton, zooplankton, and fish communities. In terms of the nutritional value of food web components, we evaluated changes in the ω-3 and ω-6 polyunsaturated fatty acids (PUFA) of phytoplankton and consumers at different trophic levels. Meanwhile, the lakes did not differ in their biomasses of phytoplankton, zoo…