RESUMO
In this paper is presented a kinetic study of the catalytic combustion of trichloroethylene (TCE) over Y-zeolites exchanged with several cations. The catalysts, based on zeolite, were prepared by ion exchange and characterized by means of physico-chemical techniques and then tested under kinetic conditions. The kinetic results obtained were interpreted using kinetic models of power-law type and Eley-Rideal. The results obtained indicate that catalyst Y-Cr is more active than Y-Co catalyst. The greater activity of catalyst exchanged with Cr can be attributed to the higher acidity that presented these catalysts.
Assuntos
Incineração , Tricloroetileno/química , Zeolitas/química , Catálise , Cromo/química , Cobalto/química , Troca Iônica , CinéticaRESUMO
The large sessile tunicate Pyura stolonifera (Pleurogona: Stolibranchiata: Pyuridae), has been regarded as a complex taxon with disjointed distributions, including Australia (Pyura stolonifera praeputialis), South Africa (Pyura stolonifera stolonifera) and South America (Chile, Antofagasta: Pyura sp., the 'piure de Antofagasta'), and has been cited under at least five taxonomic combinations. The 'piure de Antofagasta' is a competitively dominant species in rocky intertidal habitats and shows a limited geographical range (60-70 km) exclusively inside the Bay of Antofagasta. Using cytochrome oxidase I (COI) mitochondrial sequence data from Pyura specimens of the three taxa we tested whether the Chilean taxon represents: (i) a Gondwana relict; (ii) a more recently divergent species; or (iii) a recently introduced species. The results suggest that the Chilean taxon is a recent introduction to Chile from Australian populations and that Pyura stolonifera praeputialis, from Australia, and the 'piure de Antofagasta' are geographical populations of a single species: Pyura praeputialis; whereas the South African taxon represents a second species: Pyura stolonifera.
Assuntos
Urocordados/genética , Urocordados/fisiologia , Animais , Austrália , Chile , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mitocôndrias/enzimologia , Filogenia , África do Sul , Urocordados/classificaçãoRESUMO
The lake Laguna Chichancanab contains one of the evolutionarily youngest species flocks known, composed of five endemic species of the genus Cyprinodon. The presumed sister species Cyprinodon artifrons still exists in marine coastal habitats. Sequences of the mitochondrial control region were obtained for C. artifrons (genes of 17 individuals sequenced) and for all five endemic species (genes of 32 individuals sequenced). While nine different haplotypes were found in C. artifrons, only a single haplotype was shared with the species from the laguna. Four additional haplotypes were found among the endemics. These four were most closely related to that single haplotype shared with C. artifrons. The deprivation in haplotypes among the endemics points to a small founder population or to bottlenecking. The distribution pattern of overlapping haplotypes in four of the five species suggests incomplete lineage sorting or hybridization among them. Complete reproductive isolation is only assumed for one species, C. maya, in which a single and unique haplotype was found.
Assuntos
Cyprinidae/genética , Animais , Sequência de Bases , Cyprinidae/classificação , México , Dados de Sequência Molecular , RNA de Transferência de Treonina/genética , Especificidade da EspécieRESUMO
PIP: Nongovernmental organizations (NGOs) in Latin America have grown more rapidly than has our understanding of the economic and political implications of this major institutional change. In Ecuador, between 1984 and late 1992, at least 24 new environmental NGOs emerged. An economist does a case study of them, especially Fundacion Natura (FN) in Ecuador, to understand their role and behavior which are a large part of environmental politics in Latin America. NGOs are successful because the public sector cannot meet the countries' needs and donors want to help NGOs, thereby providing the demand. For example, FN has received funding from USAID, World Wildlife Fund, the International Union for the Conservation of Nature, and other groups. FN charges donors 15% to cover administrative costs while many other NGOs do not receive international funding for administrative costs. FN is well connected with the public sector which is supportive and beneficial. FN activities complement the public sector's efforts in the environment. Further, it is well connected with private industry from whom it receives financial support. It has been criticized for supporting industry on some environmental issues, however. In fact, its Cuenca chapter split from FN in 1984 to form Tierra Viva, because FN sided with industry when industry wanted to build on agricultural land in Cuenca. FN's relationship with USAID is strained. FN is successful because it employs quality personnel who are committed to FN objectives. Yet FN and other NGOs do not have the monetary incentives for efficient production. Most other NGOs are financially strapped and depend on volunteers. The more radical environmental NGOs do not accept donations from the private sector and do not want to work with government. Despite the influence donors have on NGOs, the NGOs' powerful presence and their environmental education programs have consequences beyond donor control (e.g., FN and USAID).^ieng
Assuntos
Conservação dos Recursos Naturais , Economia , Meio Ambiente , Estudos de Avaliação como Assunto , Órgãos Governamentais , Cooperação Internacional , Organização e Administração , Organizações , Setor Privado , Mudança Social , América , Países em Desenvolvimento , Equador , Administração Financeira , América Latina , Pesquisa , América do SulRESUMO
Nos alento para la presentacion de este trabajo, la rara incidencia de osteomielitis com las caracteristicas del sindrome mano-pie, sin estar asociado a la drepanocitosis. Presentamos a una nina de 3 anos de edad que, luego de un episodio de deshidratacion aguda, manifiesta un cuadro septico con hemocultivos y coprovultivos positivos para Salmonella paratyphi A. Se observa tumefaccion dolorosa en ambas manos y en ambos pies que, posteriormente, tiene manifestacion radiologica compatible con osteomielitis (imagenes en sacabocado en todos los metacarpianos y metatarsianos Se le instituyo tratamiento segun antibiograma, obteniendose una mejoria clinica y radiologica ostensible
Assuntos
Lactente , Humanos , Feminino , Osteomielite , Salmonella paratyphi ARESUMO
Nos alento para la presentacion de este trabajo, la rara incidencia de osteomielitis com las caracteristicas del sindrome mano-pie, sin estar asociado a la drepanocitosis. Presentamos a una nina de 3 anos de edad que, luego de un episodio de deshidratacion aguda, manifiesta un cuadro septico con hemocultivos y coprovultivos positivos para Salmonella paratyphi A. Se observa tumefaccion dolorosa en ambas manos y en ambos pies que, posteriormente, tiene manifestacion radiologica compatible con osteomielitis (imagenes en sacabocado en todos los metacarpianos y metatarsianos Se le instituyo tratamiento segun antibiograma, obteniendose una mejoria clinica y radiologica ostensible
Assuntos
Lactente , Humanos , Feminino , Osteomielite , Salmonella paratyphi ARESUMO
Is an acute bronchial, obstructive disease of the infant caused mainly by the respiratory syncytial virus. It appears epidemically preceded by infections of the upper respiratory ducts, followed by coughing, dysnea, expiratory sibilants, suprasternal and subcostal during inspiration and radiologic evidences of choneking. In the differential diagnosis the physician must consider pulmonary dysgenesis, diaphragmatic hernia, congenital lobar emphysema, congenital cardiopathy, pneumothorax, obstruction due to foreign body, asthmatic crisis and fibrocystic disease. Fundamentally, two diagnoses should be discarded: 1) dyspenic bacterial bronchopneumonic syndrome; 2) prime infection T. B. bronchopneumonia with bronchiolitic syndrome.