984 resultados para École de Barbizon


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Plastic debris is a widespread contaminant, prevalent in aquatic ecosystems across the globe. Zooplankton readily ingest microscopic plastic (microplastic, < 1 mm), which are later egested within their faecal pellets. These pellets are a source of food for marine organisms, and contribute to the oceanic vertical flux of particulate organic matter as part of the biological pump. The effects of microplastics on faecal pellet properties are currently unknown. Here we test the hypotheses that (1) faecal pellets are a vector for transport of microplastics, (2) polystyrene microplastics can alter the properties and sinking rates of zooplankton egests and, (3) faecal pellets can facilitate the transfer of plastics to coprophagous biota. Following exposure to 20.6 μm polystyrene microplastics (1000 microplastics mL–1) and natural prey (∼1650 algae mL–1) the copepod Calanus helgolandicus egested faecal pellets with significantly (P < 0.001) reduced densities, a 2.25-fold reduction in sinking rates, and a higher propensity for fragmentation. We further show that microplastics, encapsulated within egests of the copepod Centropages typicus, could be transferred to C. helgolandicus via coprophagy. Our results support the proposal that sinking faecal matter represents a mechanism by which floating plastics can be vertically transported away from surface waters.

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After considering museums as cultural institutions responsible for preserving cultural memory and its evolution over time, this article describes the cultural practices within our society that are aimed at disseminating art and at reproducing and transmitting culture, history and identity. Further, it considers the key role that older people are steadily assuming in Spain’s ageing society. New social-empowerment activities based on volunteering by the elderly are linked to generativity because the individual and social groups acquire new skills through those activities, thereby strengthening a society for all ages. Never in the history of social work have so many older people been prepared to participate actively at the community level, and never has a social movement with these features gone so unnoticed by so many social agents.

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The conflict’s coverage, since its inception, has been closely linked to the relationship that both the military and the media have. The freedom they maintained during their first conflicts, although not without problems, though they suffered strict censorship suffered during World War I, and lastly the straitjacket treatment that they have endured during recent wars. The Vietnam War marked a turning point in this relationship, and after the invasion of Grenada, the military would launch new information guidelines, called Department of Defense National Media Pool. The lack of clear guidance of both control and space, has made for a complicated relationship between media and military, so the rules have evolved after every conflict shaping the future of press coverage and thus, war reporting.

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Reality shows are TV programs which represent a format used in television nowadays; however, the observation practices of individual and/or group intimacy dates from thousands years ago. Sometimes this was driven by voyeurism or morbid fascination, some others, by the purpose of guarding, supervising and maintaining status quo. This work offers an alternative answer to the explanation of this type of TV program emergence and relates this appearance to a government procedure bound up with modern State terrorism which began at the end of the eighteenth century and has been recalled by different regimes until present days.

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