804 research outputs found
Catch composition, catch rates and size selectivity of three long-line methods in the Algarve (southern Portugal)
Three long-line methods have been studied in the Algarve: 1) small-hook long-line for inshore (less than 30 m) ‘white’ sea breams (Sparidae); 2) small-hook long-line for deeper water (40-60 m) ‘red’ sea breams; and 3) deep water (500-700 m) semi-pelagic long-line for hake Merluccius merluccius
(Linnaeus, 1758). Selectivity studies were carried out with three hook sizes in the first two cases: Mustad round-bent Quality 2369 hooks, numbers 15, 13, and 11, baited with a standardsized razor-shell Ensis siliqua (Linnaeus, 1758). Four hook sizes (numbers 10, 9, 7, and 5) of Stell round-bent, eyed hooks were used in the semi-pelagic long-line selectivity study, baited with a half of a standard-sized sardine. Some factors affecting catch composition and catch rates of the small
hook long-lines were also evaluated: bait, gangion length, setting time, fishing ground, and depth. Species diversity was relatively high, with 40, 36 and 27 species, respectively, in the three studies. However, the catches were dominated by a limited number of species. Catch rates (number
of fish per 100 hooks) were variable ( 20 %), with a general decrease in catch rate with increasing hook size in all the studies. In general, the catch size distributions for the different hook sizes for each species were highly overlapping, with little or no evidence of differences in
size selectivity. Hooks caught a wide size-range for each species, with few or no illegal-sized fish, in most cases. Some implications of these results for the management of multi-species, multi-gear fisheries are discussed.info:eu-repo/semantics/publishedVersio
Catch composition, catch rates and size selectivity of three long-line methods in the Algarve (southern Portugal)
Three long-line methods have been studied in the Algarve: 1) small-hook long-line for inshore (less than 30 m) ‘white' sea breams (Sparidae); 2) small-hook long-line for deeper water (40-60 m) ‘red' sea breams; and 3) deep water (500-700 m) semi-pelagic long-line for hake Merluccius merluccius (Linnaeus, 1758). Selectivity studies were carried out with three hook sizes in the first two cases: Mustad round-bent Quality 2369 hooks, numbers 15, 13, and 11, baited with a standardsized razor-shell Ensis siliqua (Linnaeus, 1758). Four hook sizes (numbers 10, 9, 7, and 5) of Stell round-bent, eyed hooks were used in the semi-pelagic long-line selectivity study, baited with a half of a standard-sized sardine. Some factors affecting catch composition and catch rates of the small hook long-lines were also evaluated: bait, gangion length, setting time, fishing ground, and depth. Species diversity was relatively high, with 40, 36 and 27 species, respectively, in the three studies. However, the catches were dominated by a limited number of species. Catch rates (number of fish per 100 hooks) were variable ( 5 %; 20 %), with a general decrease in catch rate with increasing hook size in all the studies. In general, the catch size distributions for the different hook sizes for each species were highly overlapping, with little or no evidence of differences in size selectivity. Hooks caught a wide size-range for each species, with few or no illegal-sized fish, in most cases. Some implications of these results for the management of multi-species, multi-gear fisheries are discussed.Tres artes de palangre han sido estudiados en Algarve: 1) palangre de anzuelo pequeño para espáridos de aguas costeras (menos de 30 m); 2) palangre de anzuelo pequeño para espáridos rojos de aguas mas profundas (40-60 m); y 3) palangre semipelágico de profundidad para merluza Merluccius merluccius (Linnaeus, 1758). En los dos primeros casos, los estudios de selectividad han utilizado anzuelos de tres tamaños: round bent marca Mustad modelo 2369 (números 15, 13 y 11), utilizando como cebo pedazos de navajas Ensis siliqua (Linnaeus, 1758) de la misma talla. En el estudio de selectividad con el palangre semipelágico se han utilizado cuatro tamaños de anzuelo (números 10, 9, 7 y 5) round hook de la marca Stell, con media sardina como cebo. Se evalúan, también, otros factores que afectan a la composición y a la tasa de captura de los palangres equipados con anzuelo pequeño: cebo, longitud de la puntera, hora de largada del aparejo, área de pesca y profundidad. La diversidad de especies en los tres estudios ha sido relativamente elevada: 40, 36 y 27 especies, respectivamente. Sin embargo, las capturas han sido dominadas por un número reducido de especies. Las tasas de captura (número de peces por 100 anzuelos) han variado ( 5 %; 20 %), observándose en los tres estudios un descenso general de las tasas de captura con el aumento del tamaño del anzuelo. De forma general, se ha observado una fuerte sobreposición de las distribuciones de las capturas con los diferentes tamaños de anzuelo para cada especie, con poca o ninguna evidencia de diferencias en la selectividad por talla. Los tamaños de anzuelo probados han capturado un rango de tallas amplio para cada especie, con escasa o ninguna captura de peces de talla ilegal en la mayorÃa de los casos. Se discuten algunas implicaciones de estos resultados en la gestión de pesquerÃas incluyendo varias especies y varios artes de pesca.Instituto Español de OceanografÃ
Simulation of in vitro water deficit for selecting drought-tolerant banana genotypes.
The objective of this work was to determine a method to simulate water stress in vitro to select drought-tolerant banana (Musa sp.) genotypes. The BRS Tropical and Prata Anã cultivars were grown in vitro in an MS liquid medium containing sucrose and benzylaminopurine (BAP), supplemented with different concentrations of polyethylene glycol (PEG) or sorbitol. The yield stability index of dry matter was evaluated. Cultivation for 30 days in a medium containing 15 g L-1 PEG or 36.4 g L-1 sorbitol is appropriate to simulate water stress in vitro.Notas CientÃficas. TÃtulo em português: Simulação de deficit hÃdrico in vitro para seleção de bananeiras tolerantes à seca
Comportamento meiótico e viabilidade de pólen de bananeiras autotetraploides NBA-14.
A indução da duplicação de cromossomos é uma alternativa para gerar novos triploides de bananeira resistentes a doenças e com frutos de qualidade. Os autotetraploides obtidos através desta técnica poderão ser utilizados para gerar triploides secundários (AAA) mediante o cruzamento com diploides (AA)
Efeito do teor de umidade na germinação in vitro de sementes de banana oriundas de autotetraploide induzido por duplicação dos cromossomos.
O processo de desidratação é um dos pontos cruciais para o sucesso da criopreservação de tecidos vegetais. Pois teores muito baixos levam à desidratação excessiva e morte das células, e aqueles elevados levam a formação de cristais de gelo no interior das células (1)
Competition between static gear of the small-scale fisheries in Algarve waters (southern Portugal)
Parallel fishing trials with 0.30 mm diameter monofilament gill nets and longlines using small hooks were carried out in the Algarve (southern Portugal) over a one-year period, 1997-1998, with the objective of comparing species composition, catch rates, discards and size ranges. Four hook sizes of MUSTAD brand, round bent, flatted sea hooks (numbers 15, 13, 12 and 11) and four mesh sizes of 50, 60, 70, and 80 (stretched mesh) (nominal bar length) of gill nets were used in the trials. Overall, 84 species were caught, with gill nets taking 71 species and longlines 54 species and with 41 species caught by both gear types. The amount of discarding was higher for gill nets than for longlines. The catch species composition differed between the two gear types, with the commercially valuable sea breams dominating the longline catches whereas small pelagics were relatively more important in the gill nets. Multivariate analysis showed a clear separation between the different sizes of the two gear types both in terms of numbers and weights per species. Algarve gill netters and longliners fish the same species assemblage on the same fishing grounds, but have clearly different impacts in terms of catch species composition, catch rates and sizes. This information will be useful for the improved management of these small-scale, multi-species, multi-gear fisheries, where different gear types compete for scarce resources. In particular this study provides a basis for a more rational allocation of licenses and control of fishing effort
Age, growth and reproduction of the Axilary Seabream, "Pagellus acarne" (Risso, 1827), from the South coast of Portugal
Axillary seabream, Pagellus acarne, caught by longlines in the Algarve (Southern Portugal), were
sampled between August 1995 and August 1996. Age was studied by counting growth increments on otoliths
and the estimated von Bertalanffy parameters were Linf = 28.82 cm, K = 0.29 year-1 and t0 = -1.47 year for
males and Linf = 32.30 cm, K = 0.18 year-1 and t0 = -2.56 year for females. Evidence of the annual periodicity of
the deposition of increments was found by marginal increment analyses. Macroscopic analysis of the
gonads and the gonad somatic index showed that reproduction occurred over an extensive period of
time, from May to November. Lengths at first maturity were 18.10 and 17.60 cm for males and females,
respectively. This species was characterized as being a protandric hermaphrodite.info:eu-repo/semantics/publishedVersio
Non-AIDS-related comorbidities in people living with HIV-1 aged 50 years and older: The AGING POSITIVE study.
OBJECTIVE:
To characterize the profile of non-AIDS-related comorbidities (NARC) in the older HIV-1-infected population and to explore the factors associated with multiple NARC.
METHODS:
This was a multicentre, cross-sectional study including HIV-1-infected patients aged ≥50 years, who were virologically suppressed and had been on a stable antiretroviral therapy (ART) regimen for at least 6 months. A multiple regression model explored the association between demographic and clinical variables and the number of NARC.
RESULTS:
Overall, 401 patients were enrolled. The mean age of the patients was 59.3 years and 72.6% were male. The mean duration of HIV-1 infection was 12.0 years and the median exposure to ART was 10.0 years. The mean number of NARC was 2.1, and 34.7% of patients had three or more NARC. Hypercholesterolemia was the most frequent NARC (60.8%), followed by arterial hypertension (39.7%) and chronic depression/anxiety (23.9%). Arterial hypertension and diabetes mellitus were the most frequently treated NARC (95.6% and 92.6% of cases, respectively). The linear regression analysis showed a positive relationship between age and NARC (B=0.032, 95% confidence interval 0.015-0.049; p=0.0003) and between the duration of HIV-1 infection and NARC (B=0.039, 95% confidence interval 0.017-0.059; p=0.0005).
CONCLUSIONS:
A high prevalence of NARC was found, the most common being metabolic, cardiovascular, and psychological conditions. NARC rates were similar to those reported for the general population, suggesting a larger societal problem beyond HIV infection. A multidisciplinary approach is essential to reduce the burden of complex multi-morbid conditions in the HIV-1-infected population.info:eu-repo/semantics/publishedVersio
Micropropagação de autotetraploides de bananeira obtidos por duplicação de cromossomos.
Este trabalho teve como objetivo multiplicar autotetraploides provenientes da duplicação cromossômica de quatro diploides de bananeira
Uso de indutores de estresse hÃdrico na avaliação in vitro de bananeira para tolerância ao déficit hÃdrico.
Dentre os problemas atuais enfrentados na cultura da bananeira, o déficit hÃdrico tem ganhado destaque. Esse fator abiótico tem sido considerado, em algumas situações, o principal determinante da redução de rendimento verificado em nÃvel de campo, e existe a previsão de intensificação dos efeitos desse estresse, pelas mudanças climáticas
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