Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Total Environ ; 761: 143310, 2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33183812

RESUMO

Marine litter (ML) consists of any item of anthropogenic origin that has been lost, discarded or intentionally disposed of into the environment, being acknowledged as a worldwide environmental and ecological threat. In the last decade, there has been an attempt across different sectors to tackle, reduce and mitigate sources of litter. In this study, meso and macrodebris between 2 and 30 cm was recorded and classified in two established study areas (Porto Pim and Conceição beaches), throughout five monitoring years (2012-2018). The litter abundance, density and weighted average by abundance were evaluated in eight main categories: plastics, cloths/fabrics, glass, metals, rubber, processed lumber, other and large. Field surveys provided evidence that plastic represented 95% of all litter. ML abundance was treated as an "environmental variable" and used to determine its anomalies, temporal trends and forecasts. Results from this time-series addressed possible periodic oscillations and density peaks of litter. Reference values of ML presence were obtained and could potentially be used for developing a diagnostic tool for anthropogenic pollution in the Azores.

2.
Proc Natl Acad Sci U S A ; 104(21): 9029-34, 2007 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-17488814

RESUMO

Floodwaters in New Orleans from Hurricanes Katrina and Rita were observed to contain high levels of fecal indicator bacteria and microbial pathogens, generating concern about long-term impacts of these floodwaters on the sediment and water quality of the New Orleans area and Lake Pontchartrain. We show here that fecal indicator microbe concentrations in offshore waters from Lake Pontchartrain returned to prehurricane concentrations within 2 months of the flooding induced by these hurricanes. Vibrio and Legionella species within the lake were more abundant in samples collected shortly after the floodwaters had receded compared with samples taken within the subsequent 3 months; no evidence of a long-term hurricane-induced algal bloom was observed. Giardia and Cryptosporidium were detected in canal waters. Elevated levels of fecal indicator bacteria observed in sediment could not be solely attributed to impacts from floodwaters, as both flooded and nonflooded areas exhibited elevated levels of fecal indicator bacteria. Evidence from measurements of Bifidobacterium and bacterial diversity analysis suggest that the fecal indicator bacteria observed in the sediment were from human fecal sources. Epidemiologic studies are highly recommended to evaluate the human health effects of the sediments deposited by the floodwaters.


Assuntos
Desastres , Sedimentos Geológicos/microbiologia , Microbiologia da Água , Água Doce/microbiologia , Louisiana , Microbiologia da Água/normas
3.
Protist ; 151(3): 275-82, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11079772

RESUMO

Leptomyxid amoebae encompass a diverse assemblage of amoeboid protists that have been implicated as encephalitis-causing agents. This characteristic is attributed to recent studies identifying new members of the Leptomyxidae, in particular, Balamuthia mandrillaris, that cause the disease. Their morphologies range from limax to plasmodial, as well as reticulated and polyaxial. Although systematic studies have identified B. mandrillaris as a new member of the Leptomyxidae, its precise placement within the leptomyxids is uncertain. To further assess the taxonomic placement of Balamuthia among the leptomyxid amoebae and to determine whether the members of the Leptomyxida form a monophyletic assemblage, we have sequenced 16S-like rRNA genes from representatives of three leptomyxid families. Our phylogenetic analyses revealed that current members of the order Leptomyxida do not constitute a monophyletic assemblage. Our analyses clearly show that Gephyramoeba, as well as Balamuthia do not belong in the order Leptomyxida. We highlight where molecular data give differing insights than taxonomic schemes based on traditional characters.


Assuntos
Amoeba/genética , Filogenia , RNA Ribossômico 16S , Animais , Funções Verossimilhança , Dados de Sequência Molecular , Análise de Sequência de DNA
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...