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1.
Harmful Algae ; 116: 102254, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35710203

RESUMO

Harmful algal blooms (HABs) negatively impact coastal ecosystems, fisheries, and human health, and their prediction has become imperative for effective coastal management. This study aimed to evaluate spatial-temporal variability patterns and phenology for key toxigenic phytoplankton species off southern Portugal, during a 6-year period, and identify region-specific environmental drivers and predictors. Total abundance of species responsible for amnesic shellfish poisoning (Pseudo-nitzschia spp.), diarrhetic shellfish poisoning (Dinophysis spp.), and paralytic shellfish poisoning (G. catenatum) were retrieved, from the National Bivalve Mollusk Monitoring System public database. Contemporaneous environmental variables were acquired from satellite remote sensing, model-derived data, and in situ observations, and generalized additive models (GAMs) were used to explore the functional relationships between HABs and environmental variables and identify region-specific predictors. Pseudo-nitzschia spp. showed a bimodal annual cycle for most coastal production areas, with spring and summer maxima, reflecting the increase in light intensity during the mixed layer shoaling stage, and the later stimulatory effects of upwelling events, with a higher bloom frequency over coastal areas subjected to stronger upwelling intensity. Dinophysis spp. exhibited a unimodal annual cycle, with spring/summer maxima associated with stratified conditions, that typically promote dinoflagellates. Dinophysis spp. blooms were delayed with respect to Pseudo-nitzschia spp. spring blooms, and followed by Pseudo-nitzschia spp. summer blooms, probably reflecting upwelling-relaxation cycles. G. catenatum occurred occasionally, namely in areas more influenced by river discharges, under weaker upwelling. Statistical-empirical models (GAMs) explained 7-8%, and 21-54% of the variability in Pseudo-nitzschia spp. and Dinophysis spp., respectively. Overall, a set of four easily accessible environmental variables, surface photosynthetically available radiation, mixed layer depth, sea surface temperature, and chlorophyll-a concentration, emerged as the most influential predictors. Additionally, over the coastal production areas along the south coast, river discharges exerted minor negative effects on both HAB groups. Despite evidence supporting the role of upwelling intensity as an environmental driver of Pseudo-nitzschia spp., it was not identified as a relevant model predictor. Future model developments, such as the inclusion of additional environmental variables, and the implementation of species- and period-specific, and hybrid modelling approaches, may further support HAB operational forecasting and managing over complex coastal domains.


Assuntos
Diatomáceas , Dinoflagellida , Intoxicação por Frutos do Mar , Ecossistema , Proliferação Nociva de Algas , Fitoplâncton , Portugal
2.
Mar Pollut Bull ; 174: 113296, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34995889

RESUMO

This study aimed to assess the influence of treated wastewater disposal on Ria Formosa coastal lagoon (South Portugal), the largest national producer of bivalve mollusks. Water quality was evaluated at two areas under different wastewater loads and hydrodynamic conditions, using physico-chemical variables, bacterial indicators of contamination, chlorophyll-a concentration, phytoplankton abundance and composition. Samples were collected monthly, between October 2018 and September 2019. Minor influence of effluent discharge was detected at the eastern Olhão area, exposed to stronger hydrodynamics and higher wastewater load than the northwestern Faro area (ca. 2-4-fold total nitrogen and phosphorus). The lower load weakly flushed area showed a poorer water quality, up to 500 m from the discharge point, more marked during the spring-summer period. The intensity, persistence, and spatial extent of the wastewater footprint, lower for the highest-loading area, reflected the role of local hydrodynamic conditions, modulating the influence of wastewater discharge on lagoonal water quality.


Assuntos
Águas Residuárias , Qualidade da Água , Monitoramento Ambiental , Hidrodinâmica , Portugal , Taiwan
3.
Arq. bras. med. vet. zootec. (Online) ; 71(4): 1179-1186, jul.-ago. 2019. tab, graf, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1038597

RESUMO

As lesões dos meniscos são uma das principais causas de dor e claudicação em equinos. O objetivo do presente estudo foi avaliar a morfometria dos meniscos da articulação femorotibial de equinos. Foram utilizados 48 meniscos de 12 animais de ambos os sexos, com idade entre cinco e 15 anos e com peso entre 400kg e 500kg. A medida da extensão periférica compreendeu desde a parte mais cranial à mais caudal e denominou-se circunferência externa (CE). A margem interna, com o mesmo tratamento, foi chamada de circunferência interna (CI). Os meniscos foram divididos em terços craniais, médios e caudais. A espessura foi obtida nos pontos médios de cada terço. Foi calculada a área dos meniscos em contato com os côndilos femorais. O menisco medial apresentou maior CE com média de 126,38mm, enquanto o menisco lateral apresentou média de 115,32mm. O menisco lateral mostrou maior espessura nos terços médio e caudal, com valores médios de 16,00mm e 19,85mm, respectivamente, contra 13,75mm e 14,99mm dos meniscos mediais. Os resultados deste estudo mostraram relação importante entre os dados morfométricos e os achados clínicos na tentativa de explicar a maior incidência de lesões envolvendo o menisco medial.(AU)


Meniscal lesions are one of the main causes of pain and lameness in horses. The objective of this study was to evaluate the morphometry of the meniscus of the femorotibial joint of horses. 48 meniscus were used from 12 animals, aged between five and 15 years and weighing between 400kg and 500kg. The measurement of the peripheral extension went from the most cranial part to the most caudal, denominated external circumference (CE). The internal margin, with the same treatment, was called internal circumference (IC). The meniscus was divided into cranial, middle and caudal thirds. The thickness was obtained at the midpoints of each third. The area of the meniscus in contact with the femoral condyles was also calculated. The medial meniscus presented a higher CE with a mean of 126.38mm, while the lateral meniscus presented a mean of 115.32mm. The lateral meniscus showed greater thickness in the middle and caudal thirds, with mean values of 16.00mm and 19.85mm respectively, against 13.75mm and 14.99mm of the medial meniscus. The results of this study showed an important relationship between the morphometric data and the clinical findings in an attempt to explain the higher incidence of lesions involving the medial meniscus.(AU)


Assuntos
Animais , Tíbia/anatomia & histologia , Meniscos Tibiais/anatomia & histologia , Fêmur/anatomia & histologia , Lesões do Menisco Tibial/veterinária , Cavalos/anatomia & histologia
4.
Mar Environ Res ; 136: 158-173, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29506823

RESUMO

This study evaluated the impacts of submarine groundwater discharges (SGD) on a rocky intertidal community of South Portugal, during April-November 2011. Chlorophyll-a concentration was higher at the SGD site in respect to the Reference site. Epibenthic community structure differed between sites, with an increase in Chthamalus spp. and a decrease in macroalgae coverage at the SGD site. The abundance and body size of Mytilus galloprovincialis were consistently higher at the SGD site. During mid-spring, under potentially higher SGD and less favorable conditions for coastal phytoplankton, the ecophysiological condition of M. galloprovincialis and G. umbilicalis was also higher at the SGD site. These beneficial effects on filter-feeders and herbivores probably resulted from local increases in prey availability, supported by SGD-driven nutrient inputs. Conversely, P. depressa was not favoured by SGD, probably due to a lower dependency on algae as food. The analysis of epibenthic community structure and ecophysiological condition represents a promising approach to disentangle the ecological impacts of SGD on intertidal ecosystems.


Assuntos
Organismos Aquáticos/fisiologia , Ecossistema , Monitoramento Ambiental , Água Subterrânea/química , Animais , Água Subterrânea/análise , Herbivoria , Fitoplâncton , Portugal , Água do Mar/química
5.
Mem Inst Oswaldo Cruz ; 92(1): 15-20, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9302407

RESUMO

The frequency of asymptomatic infection among relatives and neighbors of cases of visceral leishmaniasis (VL) was compared and characterization of the immunological response in these subjects was performed. Cases were from a new endemic area close to the beach and near Salvador capital of the State of Bahia, Brazil. The characterization of asymptomatic infection was made using a skin reaction test and detection of antibody to Leishmania chagasi by the ELISA test. To characterize the immunological response of these subjects with asymptomatic L. chagasi infection the cytokines profile and the lymphoproliferative response were determined after stimulation of lymphocytes by L. chagasi antigen. There was no difference in the frequency of L. chagasi infection in relatives (45%) and in neighbors (27%) of cases of VL (P > 0.05). The immunological response from these subjects was characterized by high production of IFN-gamma and a low production of IL-10 and a good lymphoproliferative response to L. chagasi antigen.


Assuntos
Leishmania infantum , Leishmaniose Visceral/diagnóstico , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Feminino , Humanos , Leishmaniose Visceral/parasitologia , Masculino , Pessoa de Meia-Idade
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