Population structure and variance effective size of red snapper (Lutjanus campechanus) in the northern Gulf of Mexico*

We assayed allelic variation at 19 nuclear-encoded microsatellites among 1622 Gulf red snapper (Lutjanus campechanus) sampled from the 1995 and 1997 cohorts at each of three offshore localities in the northern Gulf of Mexico (Gulf). Localities represented western, central, and eastern subregions within the northern Gulf. Number of alleles per microsatellite per sample ranged from four to 23, and gene diversity ranged from 0.170 to 0.917. Tests of conformity to Hardy-Weinberg equilibrium expectations and of genotypic equilibrium between pairs of micro-satellites were generally nonsignificant following Bonferroni correction. Significant genic or genotypic heterogeneity (or both) among samples was detected at four microsatellites and over all microsatellites. Levels of divergence among samples were low (FST ≤0.001). Pairwise exact tests revealed that six of seven “significant” comparisons involved temporal rather than spatial heterogeneity. Contemporaneous or variance effective size (NeV) was estimated from the temporal variance in allele frequencies by using a maximum-likelihood method. Estimates of NeV ranged between 1098 and >75,000 and differed significantly among localities; the NeV estimate for the sample from the northcentral Gulf was >60 times as large as the estimates for the other two localities. The differences in variance effective size could ref lect differences in number of individuals successfully reproducing, differences in patterns and intensity of immigration, or both, and are consistent with the hypothesis, supported by life-history data, that different “demographic stocks” of red snapper are found in the northern Gulf. Estimates of NeV for red snapper in the northern Gulf were at least three orders of magnitude lower than current estimates of census size (N). The ratio of effective to census size (Ne/N) is far below that expected in an ideal population and may reflect high variance in individual reproductive success, high temporal and spatial variance in productivity among subregions or a combination of the two.

Length-weight relationship of fishes from Yemen waters (Gulf of Aden and Red Sea)

The data for this study were gathered between 1993 and 1996 on board commercial trawlers from Somalia, China and Yemen and also from the research vessel Ibn Magid belonging to the Marine Science and Resources Research Centre, Aden, Republic of Yemen. Fish were identified using the FAO species identification literature. All fish were measured to the nearest mm (total length) and weighed to the nearest g. Sex was determined by dissection after the length and weight had been measured. The length-weight relationships were calculated using least-squares regression on log-transformed data and the parameters of the relationship of the form of W=aL super(b) are summarized. Maximum and minimum size of fish sampled are also given. Common names and recent changes in nomenclature were taken from ICLARM's FishBase.

Configuración de una red de sensores inalámbricos para adquisición de datos en tiempo real. Acondicionamiento y procesado de señales mediante FPGAs.

El análisis de las vibraciones es utilizado comúnmente en el mantenimiento de los motores. Es por ello que en la industria resulta imprescindible la monitorización de todas las máquinas que estén en funcionamiento; ya que el fallo de uno de los equipos puede causar grandes pérdidas. La adquisición de las vibraciones mediante una red de sensores y el posterior procesado de datos permiten monitorizar en tiempo real el estado de cada uno de los motores. Este trabajo tiene como objetivo diseñar e implementar un sistema para la medición de vibraciones y su posterior procesado para el análisis de los datos en el dominio de la frecuencia. La toma de datos éstos se realizará mediante una red de sensores inalámbricos, haciendo uso de un acelerómetro, y el procesado mediante una FPGA.

El resultado internacional de las nuevas empresas. Una visión relacional asociada a la orientación al mercado de la red

[ES] Este trabajo profundiza en el estudio de los factores que influyen en la competitividad internacional de las nuevas empresas internacionales y, en consecuencia, en su resultado internacional. Aunando las disciplinas del emprendedurismo y del marketing internacional, se trata de remarcar la importancia del conocimiento relacional a través de la influencia de la orientación al mercado de la red en los resultados internacionales logrados por estas empresas en base al efector mediador de las ventajas competitivas. Los resultados obtenidos del contraste de hipótesis, mediante modelos de ecuaciones estructurales y análisis multi-muestra, confirman que la orientación al mercado de la red resulta determinante en la obtención de resultados internacionales superiores por parte de las nuevas empresas. Esta influencia se produce de forma indirecta a partir del efecto mediador de las ventajas competitivas en diferenciación y costes desarrolladas por las mismas. Este estudio extiende la investigación pasada en torno al emprendedurismo internacional, incluyendo nuevas aportaciones propias de la disciplina del marketing respecto a los antecedentes de la competitividad y los resultados de las nuevas empresas internacionales en los mercados exteriores. Además, los resultados obtenidos animan a emprendedores en el contexto internacional a considerar el valor explícito de otros factores distintos al conocimiento experiencial, que la empresa adquiere de forma gradual conforme se incrementa su experiencia en el mercado exterior, para darse cuenta del valor potencial que el conocimiento relacional asociado a la orientación al mercado de la red tiene como antecedente para la consecución de ventajas competitivas en el mercado internacional.

Fisheries of the Farasan Islands (Red Sea)

The fisheries of the Farasan Islands (Saudi Arabia, Red Sea) are described. The fishery resources are exploited by artisanal, investor and industrial sectors. The artisanal fishery consists mostly of line fishing around coral reefs and about half the fishing effort occurs within the proposed marine protected area (MPA). Activities by investor and industrial fisheries sector include line fishing, gill netting, fish trapping and demersal fish trawling. The relevant resource management issues that need to be addressed as part of a planning study for the establishment of a MPA are also presented. The major issues are: (1) the decline in the catch of the artisanal fishery; (2) by catch and habitat degradation; (3) sustainability in the collection of giant clams and pearl shells; and (4) the lack of information such as the importance of MPA to fisheries, stock assessment and catch and effort data. A significant role in the future management of the fisheries has been identified for the traditional representatives of the artisanal sector.

Genetic diversity and selective breeding of red common carps in China

China has a very rich genetic diversity in common carp (Cyprinus carpio) and the red common carp plays an important role in Chinese aquaculture and genetic studies. Selective breeding, particularly crossbreeding has been applied successfully to red common carps in China, and the products of these efforts have been in commercial use since the 1970s. However, knowledge of the quantitative and molecular genetics of these carps is limited. Studies were therefore undertaken to: (1) understand the genetic diversity and genetic relationship of red common carps in China; (2) understand the inheritance of color phenotype of Oujiang color carp; (3) select stable Oujiang color carp with fast growth rate and ornamental Oujiang color carp comparable with the Koi common carp from Japan; (4) study the culture performance and culture systems suitable for the Oujiang color carp in cages and paddies; (5) extend better quality fish and appropriate culture systems for small scale fish farmers in poor areas.

Potentials for different models for freshwater aquaculture development in the Red River Delta (Vietnam) using GIS analysis

This study was an attempt to apply land-based GIS analysis for freshwater aquaculture planning in the Red River Delta of Vietnam. It was based on diverse data sources in order to help decision makers at the site and also to contribute to the modelling of selection processes for aquaculture development planning in the region.

Sínteses e caracterizações de TiO2 puro, dopado e co-dopado pelo método sol-gel e suas atividades fotocatalíticas

Nanopartículas de dióxido de titânio vêm sendo extensamente empregadas como fotocatalisa-dores, já que são eficientes na degradação de diversos poluentes. Visando a obtenção de titâ-nias com diferentes propriedades, realizaram-se sínteses através do método sol-gel, a partir da hidrólise do tetraisopropóxido de titânio (IV) TIPP e seguindo-se os princípios da Química Verde, dispensando-se temperaturas e pressões elevadas. Foi estudada a influência de dife-rentes parâmetros, como: pH, solvente, razão molar álcool/TIPP e ordem de adição dos rea-gentes. Foram obtidas titânias na forma cristalina anatásio, nanométricas, com elevadas áreas superficiais específicas e predominantemente mesoporosas. Visando-se obter titânias com melhores propriedades óticas, isto é, capazes de sofrer a fotoativação pela luz visível, foram sintetizadas titânias dopadas e co-dopadas com os metais ferro e rutênio (Fe3+ e Ru3+) e o a-metal N (N3). A síntese desses materiais também foi realizada através do método sol-gel, sendo a dopagem realizada durante o processo de hidrólise. As amostras foram caracterizadas na forma de pó por difração de raios-X, adsorção-dessorção de nitrogênio, microscopia ele-trônica de varredura e espectroscopia de refletância difusa no UV-Visível. A titânia pura a-presentou como única fase cristalina o anatásio, quando calcinada até 400 C, com a presença de traços de brookita. A partir de 600 C, observou-se o aparecimento da fase rutilo, que em 900C foi a única fase encontrada na titânia. A dopagem com Ru3+dificultou a transformação de fase anatásio para rutilo, ao contrário da dopagem com Fe3+. O processo de co-dopagem acelerou a formação de rutilo, que se apresentou como única fase nas amostras calcinadas a 600 C. As titânias dopadas apresentaram uma leve diminuição na energia de bandgap, sendo os dopantes capazes de deslocar a absorção para o vermelho. Foram realizados testes fotoca-talíticos visando à degradação do azocorante Reactive Yellow 145 com lâmpada de vapor de mercúrio de 125 W a fim de se comparar as atividades fotocatalíticas das titânias puras, dopa-das e co-dopadas, calcinadas a 300C. De todas as titânias sintetizadas, a titânia pura foi a que melhor degradou o corante, tendo um desempenho semelhante ao do TiO2 P25, da Evo-nik