6 research outputs found

    Seasonal variability of stable carbon isotopes (<delta>13CDIC) in the Skagerrak and the Baltic Sea: Distinguishing between mixing and biological productivity

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    We documented the annual cycle of the carbon isotopic composition of dissolved inorganic carbon (δ13CDIC) in the water columns of the Skagerrak and Baltic Sea to obtain an increased understanding of the processes involved controlling the carbon isotopic distribution in shelf seas. The lowest δ13CDIC values (-4.9‰) were found in the low-oxygen, brackish Baltic bottom water whereas the highest values (+1.8‰) were observed in the surface water of the Skagerrak during late summer. Photosynthesis drove the high δ13CDIC values (between 1.0 and 1.8‰) noted in the surface waters of both the Skagerrak and the Baltic. The δ13CDIC values below the halocline in the Baltic reflect mixing of brackish water and the more saline water from the Skagerrak, and foremost organic matter remineralization processes that release significant amounts of low-δ13C CO2. Similarly, in the stagnant fjord basins, little deep water exchange and the degradation of terrestrial and marine organic matter set the δ13C composition. Deep-water renewal in the fjord basins resulted in rapid increases of the δ13CDIC on the order of 1‰, whereas remineralization processes caused a decrease in δ13CDIC of 0.1-0.3‰ per month depending on location. The combined effects of water mixing and remineralization processes (estimated using apparent oxygen utilization (AOU) values) yielded the expression: δ13CDIC =0.032*S-0.01*AOU-0.12 for the Baltic - Skagerrak region at water depths below the halocline

    Adolpho Lutz and controversies over the transmission of leprosy by mosquitoes Adolpho Lutz e as controvérsias sobre a transmissão da lepra por mosquitos

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    During his years of study in Switzerland and Germany, Adolpho Lutz published his first articles on zoology, clinical practice, and therapeutics. In Limeira, São Paulo, he began studies on animal and human diseases caused by germs and parasites. In 1885-86, Lutz traveled to Hamburg to study the morphology of germs related to skin diseases, in conjunction with Paul Gerson Unna, one of Germany's foremost dermatologists. He proposed the inclusion of Hansen's and Koch's bacilli in a new genus. In 1889, Unna nominated his student as physician-in-chief of the Leper Settlement on Molokai Island, Hawaii. From then on, Lutz sustained the theory that the disease was transmitted by mosquitoes. He conducted research to prove this theory when he was head of the Instituto Bacteriológico de São Paulo (1893-1908) and, later, after he moved to the Instituto Oswaldo Cruz (1908-1940). Although this research was not successful, on commissions and at congresses in which he participated until his death in October 1940, he still held to his conviction that leprosy was transmitted by mosquitoes.<br>Quando estudava na Suíça e Alemanha, Adolpho Lutz publicou os primeiros trabalhos sobre zoologia, clínica e terapêutica. Em Limeira, São Paulo, iniciou estudos sobre doenças humanas e animais causadas por germes e parasitas. Em 1885-86, viajou para Hamburgo para estudar microrganismos relacionados a doenças de pele sob a orientação de Paul Gerson Unna, um dos mais renomados dermatologistas alemães. Propôs a inclusão dos bacilos de Hansen e Koch num novo gênero. Em 1889, Unna indicou seu discípulo como chefe dos serviços médicos do Leprosário de Molokai, no Havaí. Lutz passou a defender a transmissão da doença por mosquitos. Realizou pesquisas para provar esta teoria depois que assumiu a chefia do Instituto Bacteriológico de São Paulo (1893-1908) e, sobretudo, após a transferência para o Instituto Oswaldo Cruz (1908-1940). Apesar de não terem sido bem-sucedidas estas pesquisas, sustentou a transmissão da lepra por mosquitos nas comissões e congressos de que participou, até sua morte em outubro de 1940
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