A new method for the study of essential fatty acid requirements in fish larvae

This study describes a methodology with potential application in the estimation of essential fatty acid (EFA) requirements of fish larvae. Senegalese sole (Solea senegalensis) larvae were fed, from 16 days after hatching (DAH), on Artemia enriched with different oils, inducing graded dietary concentrations of DHA: (1) soyabean oil, containing no measurable amounts of DHA (NDHA); (2) fish oil, inducing a medium DHA level (MDHA, 3 g DHA/100 g fatty acids); and (3) a mixture of Easy DHA Selco and Microfeed, resulting in high DHA content (HDHA, 8 g/100 g). At 28 DAH a metabolic trial was conducted where larvae were tube fed [1-(14) C]DHA, in order to determine its absorption, retention in the gut and body tissues, as well as its oxidation. At 23 DAH the HDHA treatment induced a significantly higher larval growth, while at 32 DAH significant differences were only found between the NDHA and HDHA treatments. The absorption of tube-fed [1-(14) C]DHA was extremely high (94-95%) and independent of feeding regime. However, in larvae fed NDHA Artemia, a significantly higher amount of label was retained in the gut compartment and a concurrently lower retention was measured in the body. A significantly higher proportion of the absorbed DHA label was oxidized in larvae fed HDHA, compared to NDHA. Based on these results, we suggest that increasing dietary supply of DHA above the larval requirement level results in its increased oxidation for energy purposes and we propose potential applications of the tube feeding methodology using radiolabelled EFA in conjunction with dose-response studies.'Fundacao para a Ciencia e a Tecnologia', Portugal [SFRH/BD/4902/2001]; FEDER, European Commission [PROMAR/SP5.P117/03

A glance at the competing values framework of Quinn and the Miles & Snow strategic models: Case studies in health organizations

AbstractThe present research seeks to describe and understand how strategy influences leadership and how this in turn interacts in the process of innovation and change in health organizations.This is an exploratory and descriptive study that involved five health organizations: four Portuguese and one Spanish. We used a mixed approach of research (qualitative and quantitative), which enabled us to understand, through case study, how strategy and leadership were articulated with innovation in these five health organizations.Despite their complexity and specificity, both the model of Miles & Snow (organizational strategy) and the model of the Competing Values Framework of Quinn (organizational culture and leadership), suitably adapted, have proven heuristic power and are able to be applied to healthcare organizations.Public and private healthcare organizations, as well as public–private partnerships, can be tracked and monitored in their processes of innovation and change in order to understand its kind of culture, leadership or organizational strategy adopted.Health organizations coexist in a continuum, where the environment (internal and external) and time are key factors which determine the strategy to be adopted. Here too depending on the dynamic and complex reality where the organization moves, there are no pure types. There is indeed a great organizational plasticity and flexibility.Leaders usually carry the formal authority by circular normative. They are not pairs (or primi inter pares). Instead they are, sometimes, in a position of superiority, when the best thing is partnership, collaboration, cooperation, building consensus and cooperation with all stakeholders, in order that they are the real protagonists and facilitators of change and innovation

The abundance and diversity of larval and juvenile fish in a Tropical estuary

The larval and juvenile fish of the Cayenne river estuary (French Guiana, South America) were sampled at two stations from June 1989 until October 1990. A total of 52989 individuals from 59 species, some still incompletely identified, were collected. Three families, #Engraulidae, #Gobiidae and #Scianidae$, accounted for over 97% of the total number of juveniles. The analysis of data over this period showed low diversity, and a difference in diversity between the two sampling locations (H' = 1.24 and 1.68). The results conform to some theoretical models of abundance that suggest a relative equilibrium of juvenile assemblages. In contrast, the seasonal variations in diversity and abundance and the results of a correspondence analysis showed significant differences in species distribution and in their relative abundance at the two sampling locations at certain periods, mainly in the rainy season. Our study indicates that, in spite of an apparent stability, the year to year variation in salinity and freshwater inputs could affect juvenile recruitment of some species and induces modifications in the composition of larval and juvenile estuarine fish assemblages. (Résumé d'auteur

Disseny i anàlisi d'una taula de snowboard

L'objectiu del projecte és el disseny i l'anàlisi d?una taula de snowboard. Pel que fa el disseny, l'objectiu serà intentar reduir el pes mantenint les prestacions actuals o millorant-les. D'altra banda, es realitzarà un anàlisis i simulació del disseny a través del mètode dels elements finits per computador

Quantitative sampling of freshwater shrimps : comparison of two electrofishing procedures in a Caribbean stream

Two electrofishing procedures (point abundance sampling and removal sampling) for estimating community structure and the abundance of freshwater shrimps (#Decapoda : #Natantia) were compared at five sites in the Grand-Carbet River, Guadeloupe, French West Indies, on the basis of species richness, species frequency and the length of caught individuals. Sampling was carried out using battery-powered portable electric fishing gear. Both point abundance sampling and removal procedures highlighted a steep longitudinal gradient related to the shrimp fauna and non consistent discrepancy was observed between the two procedures in the different sites. Thus, the choice of one of these two procedures will depend only on the study objective. The benefits and disadvantages of these two electrofishing procedures are concisely discussed. (Résumé d'auteur

Zonation longitudinale des peuplements ichtyques avant mise en eau de la retenue de Petit-Saut (Guyane française)

La composition et la structure des peuplements ichthyques du fleuve Sinnamary en Guyane française sont étudiées en fonction des grands types d'unités morphologiques (biefs, petits affluents, rapides) et de leur position dans le gradient amont-aval. Cette étude est une étude de référence des peuplements piscicoles avant mise en eau du barrage de Petit-Saut. Elle a permis également de déterminer si le remplissage de la retenue va faire disparaître des zones aux caractéristiques spécifiques marquées ou comportant des espèces endémiques. Les résultats montrent que la zonation longitudinale est ici encore moins marquée que dans les fleuves d'Afrique de l'Ouest et correspond à un accroissement de la richesse spécifique vers l'aval par ajout d'espèces aux affinités marines plus fortes plutôt qu'à un remplacement progressif des espèces. Au total 85 prélèvements ont été réalisés dans des biefs, 26 dans des petits affluents et 10 dans des rapides. Les zones qui seront noyées par le barrage ne présentent pas de peuplements aux caractéristiques marquées. Une seule espèce trouvée dans cette zone n'a pas été retrouvée ailleurs dans le fleuve. Les biefs de la zone située en aval du barrage présentent quant à eux une structure et une composition spécifique plus caractéristique (24 espèces propres), marquée essentiellement par la présence d'espèces à forte affinité marine. Vu la mauvaise qualité de l'eau relarguée par le barrage, ces peuplements sont les plus exposés aux impacts de l'ouvrage. Dans les premiers mois qui ont suivi la mise en eau seules 6 de ces 24 espèces (dont 5 Clupéiformes) n'ont pas été retrouvées au cours des pêches réalisées tant dans la retenue que dans les criques et les biefs aval. Il sera cependant essentiel de suivre l'évolution de ces populations lorsque la situation se sera stabilisée dans la retenue et que le barrage entrera dans sa phase d'exploitation. (Résumé d'auteur

Les stratégies de reproduction et les premiers stades de vie des poissons du fleuve Sinnamary (Guyane française) : une revue bibliographique

Le barrage hydro-électrique de Petit-Saut, construit par Electricité de France sur le fleuve Sinnamary en Guyane française, a été fermé en janvier 1994. Cet ouvrage a profondément modifié un milieu dont les éléments avaient co-évolué depuis de nombreuses années sans intervention humaine majeure. Face aux nouvelles conditions de milieu, certains paramètres des stratégies de reproduction des espèces qui se maintiendront à l'aval du barrage ou dans la retenue devraient évoluer. Ces modifications de milieu auront aussi un profond impact sur leurs permiers stades de vie. Le travail présenté ici a pour but de faire un inventaire des informations disponibles, dans la littérature scientifique et dans celle des aquariophiles, relatives aux principaux traits biologiques de différentes espèces appartenant aux genres représentés dans le fleuve Sinnamary. Malgré de nombreuses lacunes, ces données apportent le cadre bibliographique nécessaire au programme de recherches en cours destiné à déterminer les stratégies de reproduction des espèces qui se maintiendront à l'aval du barrage de Petit-Saut et dans la retenue. (Résumé d'auteur

Novas tecnologias, mídias sociais e democracia

This article aims to consider the impact of new technologies in the Brazilian elections of 2018, questioning about the possibilities of its transformation with the prominent use of social networks to directly connect citizens and candidates, without the customary intervention of political parties and traditional media. It also aims to discuss the role of fake news in the electoral process and the means to fight it, so it does not denature the free thought formation as a human right essential to the practice of citizenship in the new digital age.Este artículo tiene como objetivo considerar el impacto de las nuevas tecnologías en las elecciones brasileñas de 2018, cuestionando sobre las posibilidades de su transformación con el uso destacado de las redes sociales para conectar directamente a los ciudadanos y los candidatos, sin la intervención habitual de los partidos políticos y los medios de comunicación tradicionales. También se pretende discutir el papel de las noticias falsas en el proceso electoral y los medios para combatirlas, para que no desnaturalicen la formación del libre pensamiento como derecho humano esencial para el ejercicio de la ciudadanía en la nueva era digital.Este artigo visa considerar o impacto das novas tecnologias nas eleições brasileiras de 2018, questionando as possibilidades de sua transformação com o uso proeminente de redes sociais para conectar diretamente cidadãos e candidatos, sem a habitual intervenção dos partidos políticos e da mídia tradicional. Visa também discutir o papel das falsas notícias no processo eleitoral e os meios para combatê-las, para que não desnaturalize a livre formação do pensamento como um direito humano essencial à prática da cidadania na nova era digital