4,704 research outputs found
Desenvolvimento e caracterização de latões ecológicos
O chumbo é um elemento de liga normalmente presente na composição química dos latões conferindo-lhes boa maquinabilidade.
Todavia, sendo um elemento tóxico, a sua presença é possível fonte de contaminação de águas, com eventuais danos
para a saúde pública e para o ambiente. Por essa razão, a legislação publicada em vários Países tem vindo a demonstrar a
sua preocupação neste domínio, restringindo ou eliminando o teor deste elemento nos latões, particularmente nos produtos
que estão em contacto directo com a água para consumo humano, como torneiras, acessórios de canalização e tubagens
Investigação das argamassas antigas de revestimento da Redução Jesuítica Guarani, São Miguel Arcanjo, Brasil
A Redução Guaranítica de São Miguel Arcanjo, um dos sete povos missioneiros que se instalaram no noroeste do estado do Rio Grande do Sul, Brasil, por volta de 1687 no atual sítio, e parte de um dos trinta povos formados pela Companhia de Jesus. Dada a sua relevância histórica para o Brasil, este estudo tem como objetivo principal caracterizar analiticamente a constituição físicoquímica das argamassas originais, que ainda pontualmente são encontradas na Ruína, identificar seus principais materiais constituintes, bem como a existência ou não da cal e a forma com que esta se apresenta. Resultados obtidos, por microscopia eletrônica de varredura (MEV-EDS), difração de raios X (DRX), espectroscopia no infravermelho por transformada de Fourier (FTIR), análise granulométrica e análise por termogravimétrica (TG/DTG) indicam que a fonte principal de aglomerante era a cal. Cal, de origem animal ou pétrea, com a presença da cal calcítica em ambos os conjuntos de amostras. Os estudos mostram a presença da variação do carbonato de cálcio em aragonita nas amostras internas e de hidroxiapatita nas externas. Assim, com base neste estudo, busca-se de modo simplificado facilitar o trabalho de investigação de uma obra de restauro, com a criação de uma rotina básica para conhecimento e caracterização da matéria a ser restaurada se necessário para posterior intervenção
Sigmoid colon perforation at CT colonography secondary to a possible obstructive mechanism: report of a case
We report a case of colonic perforation in CT colonography, which was observed in a sigmoid colon segment contained within an inguinal hernia. At surgery, apart from the perforation, a normal large-bowel wall was found. Although rare, perforation may occur in patients with normal bowel wall, possibly resulting from a mechanical strain caused by gaseous overdistention. Radiologists performing the procedure must be aware of this possibilit
Additions to the lichen flora found on Cryptomeria japonica D. Don, in the Azores.
Twenty-nine lichens species were reported in samples from Azorean Cryptomeria japonica
forests. One species, Ramalina peruviana Ach., is newly recorded for the Macaronesian
Region. On Cryptomeria japonica, seven new lichen records were found for the Azores:
Parmotrema bangii (Vain.) Hale, Pyrrospora quernea (Dickson) Körber, Pyxine
subcinerea Stirt., Ramalina implectens Nyl., Ramalina peruviana Ach., Usnea dasaea
Stirton and Usnea esperantiana P. Clerc.The species Ramalina peruviana Ach., is rare
within the Macaronesian Region
Informal Trade of Psychoactive Herbal Products in the City of Diadema, SP, Brazil: Quality and Potential Risks
The present study aimed to assess the quality and risks involved in the consumption of psychoactive herbal products (PHs) that are available through informal commerce in the city of Diadema, SP, Brazil. Methods of ethnography were used to conduct the fieldwork during which four dealers were selected to record the collection, handling, packaging, types of PHs marketed, and their therapeutic purposes. in addition, lots of the PHs selected were purchased from the dealers and analyzed using microbiology and pharmacognosy techniques. 217 PHs were recorded and categorized into two main groups: stimulants (67%) and depressants (27%) of the central nervous system; sixteen of them were selected, and their 52 lots were acquired. the deficiencies observed in handling and packaging these lots by dealers were confirmed by microbiological analysis; 80.8% of them presented risk according to the indicators defined by the Brazilian Pharmacopoeia. the pharmacognostic analysis confirmed the authenticity of only 9 to 16 PHs analyzed. in addition, descriptions of contraindications, adverse reactions, and drug interactions were found in the literature for the PHs. the results of this study allow the observation of the priorities for the sanitary adequacy of the popular trade of herbs.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)AFIP-Associacao Fundo de Incentivo a PesquisaUniversidade Federal de São Paulo, Dept Med Prevent, BR-04038034 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, Ctr Estudos Etnobot & Etnofarmacol, BR-09972270 Diadema, SP, BrazilUniv São Paulo, Dept Farm, BR-05508000 São Paulo, BrazilAdolfo Lutz Inst, Ctr Medicamentos Cosmet & Saneantes, BR-01246902 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, BR-04023062 São Paulo, BrazilUniv Bandeirante Anhanguera, BR-02071013 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Med Prevent, BR-04038034 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, Ctr Estudos Etnobot & Etnofarmacol, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, BR-09972270 Diadema, SP, BrazilWeb of Scienc
Efeito do silício em alguns componentes de resistência a antracnose em linhagens de sorgo.
xEdição dos Resumos do XL Congresso Brasileiro de Fitopatologia, Maringá, PR, ago. 2007
Bird extinctions and introductions are causing taxonomic and functional homogenization in oceanic islands
Humans are quickly reshaping species assemblages through the loss and gain of species at multiple scales. Extinctions and introductions are non-random events known to be contributing to taxonomic homogenization. However, it is not yet clear if they also promote functional homogenization. Here, we assess whether extinctions and introductions are leading to taxonomic and functional homogenization of 64 oceanic island bird assemblages, belonging to 11 archipelagos. Based on island lists of extinct and extant, native and introduced species and on species traits, we use probabilistic hypervolumes in trait space to calculate functional beta-diversity before and after extinctions and introductions. Bird extinctions and introductions promoted taxonomic and functional homogenization on most oceanic islands. These results follow our expectations, considering previous studies on taxonomic homogenization, the predictable link between taxonomic and functional diversity, and the trait similarity of many introduced species, often adapted to anthropogenic habitats, linked to the non-randomness of bird introductions on islands. Taxonomic homogenization was more common across than within archipelagos, also corroborating previous studies describing stronger homogenization on islands that are further apart and thus had distinctive native assemblages. Surprisingly, the widespread loss of species with similar traits, namely large flightless birds, often led to functional differentiation across archipelagos. However, this differentiation effect tended to be offset by the homogenizing effect of introductions. Functional homogenization increases the vulnerability to global changes, by reducing the variability of responses to disturbance and thus the resilience of ecosystem services, posing a threat to human societies on islands. Our results highlight subtle variations in taxonomic and functional beta-diversity of bird assemblages in oceanic islands, providing important insights to allow a better assessment of how anthropogenic changes might alter ecosystem functioning, which is vital to develop effective long-term conservation strategies. Read the free Plain Language Summary for this article on the Journal blog.Peer reviewe
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