969 resultados para Jeanroy, Alfred, 1859-1953.
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Périodicité : Trimestriel
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In the mid-20th century, the southern parts of the Madres and Mont Coronat massif (Eastern Pyrenees, France) were characterized by a Mediterranean landscape shaped by human activity. Long-term use of these mountains for crops, livestock, and forestry led to an increase in grassland areas at the expense of forest. However, socioeconomic transformation (abandonment of agriculture and a decrease in the rural population) in recent decades has caused profound changes in this massif. Interpretation of aerial photographs (1953, 1969, 1988, and 2000) made it possible to detect and analyze the changes produced in the study area (6787 ha) during this period. In 1953 most of the massif landscape consisted of grasslands (38%) and open forests (18%), with some areas of dense forest (15%). By 2000, dense forest cover had doubled in size (31%), and grassland had decreased considerably (by 73% of the initial area). Since 1953, the study area has become more homogeneous, with a few local exceptions. The results of this study suggest that socioeconomic factors might be the main cause of landscape transformations in this period of approximately 50 years.
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The centenary of Alfred Werner's Nobel Prize in Chemistry has prompted this retrospect on his important contributions for the development of stereochemistry and for the understanding of the nature of the coordination compounds. His genealogy has been described, including a discussion on the famous Jørgensen-Werner controversy. As an extension, it has also been reported the German biography of Heinrich Rheinboldt, the founder of the Chemistry School at the University of São Paulo, and his relation with Werner's scientific heritage.
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1872/10/26 (Numéro 1953).
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14 x 21 cm
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Kirjallisuusarvostelu
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A morfologia, os parâmetros citomorfométricos e os glicoconjugados presentes na pseudobrânquia de guaru, Poecilia reticulata Peter, 1859 (Cyprinodontiformes: Poeciliidae), foram investigados por microscopia de luz acoplada ao sistema de captura e análise de imagens, juntamente por histoquímica com lectinas. A anatomia microscópica indicou que P. reticulata possui pseudobrânquia glandular formada por dois lóbulos, a qual se localiza abaixo do epitélio faringiano. O órgão é constituído por parênquima vascularizado e rico em células pseudobranquiais. Esse tipo celular exibe estado citofisiológico ativo, com abundante sistema de biomembranas e ausência de óstio na superfície apical,que por sua vez é encontrado nas células ricas em mitocôndrias das holobrânquias. Assim, indica-se que as células da pseudobrânquia se distinguem das células das holobrânquias em relação à morfologia, histoquímica e fisiologia. Em decorrência dessas características intrínsecas, a pseudobrânquia de alevinos do guaru pode desempenhar funções não respiratórias nas fases iniciais do desenvolvimento. Além disso, a caracterização da pseudobrânquia do guaru possibilitará estudos futuros sobre o efeito de poluentes aquáticos em espécies biomonitoras, como P. reticulata.
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Luettelo Kansalliskirjastossa olevan Alfred Anderssénin arkiston sisällöstä