Effects of Additives upon Percolation Temperature in AOT-Based Microemulsions

In the present review the percolative phenomena has been analyzed. Percolation is related to transport phenomena in microemulsions, in particular the electric charge transport. The influence of different additives upon electric percolation has been commented. The effects of the additives considered upon the microemulsion properties appear to come about through their association with the surfactant interface. The effects of these agents on the ease with which interdroplet channels allowing transfer of droplet contents are formed are not only responsible for their effects on percolation temperature, but also have serious implications for the rates of fast chemical reactions performed in microemulsions

Reproductive activity of swordfish Xiñhias gladius, in the Atlantic Ocean inferred on the basis of macroscopic indicators

Regions with intense maturation-reproduction processes versus other regions showing less frequent, sporadic and non-existent maturation events were characterized on the basis of the gonadal index of 18,279 female swordfish. Females larger than 145 cm lower jaw-fork length (LJFL) may present high or low gonadal index values depending on the region and season. The highest gonadal indices were observed mostly in areas having Sea Surface Temperature (SST) ranging between 24°-29°C. However, the reproductive activity of females appears to be mainly restricted to the warmer epipelagic layers of the western regions with a deeper thermocline. The size at first maturity of females (LJFL50) was estimated at 146.5 cm LJFL and the maturity function was pm= 1 / (1 + e(-0.1398 (LJFL-146.5))). Qualitative maturity indicators of females support the results obtained using gonadal indices. According to catch rate data by size, sex and region, the presence of males 125- 165 cm LJFL would account for the high prevalence of males in regions where the most intense reproductive processes were observed. The characteristic ‘spawning’ related sex-ratio at size patterns are explained by thi s positive anomaly in these regions favouring males in a ratio up to 9 or 11 times greater than the abundance of females within the same medium size range. The complex reproductive process of this species would point to the practice of courting rituals, which would explain the migratory pattern of this species and its stratification by area-size-sex.Postprint0,604

El enigma del marrajo dientuso del stock norte del Atlántico

Este resumen divulgativo trata sucesos ocurridos desde 2017 y avances recientes sobre el marrajo dientuso del stock Norte del Atlántico. Algún científico ha sugerido que la falta de datos afectó a la evaluación más reciente de este stock. Pero ese argumento decae al conocer antecedentes, información y literatura disponible; más allá del rumor o la autojustificación

UPDATED STANDARDIZED CATCH RATES OF SWORDFISH (Xiphias gladius) CAUGHT BY THE SPANISH SURFACE LONGLINE FLEET IN THE INDIAN OCEAN DURING THE 2001-2018 PERIOD

Standardized catch rates of the Spanish surface longline fleet targeting swordfish are provided for the period 2001-2018. Generalized Linear Models (GLM) log-normal were used to update standardized catch rates in number of fish and in weight. Factors such as area, quarter, gear and bait, as well as the fishing strategy (based on the ratio between the most prevalent species and that appreciated most by skippers) were taken into account. The model explained 54% and 57% of CPUE variability in number and weight, respectively

La tintorera, la ciencia, la creencia y la fe

Al debatir, es importante establecer si nos moveremos sobre la evidencia y la ciencia, o si usaremos la creencia, la fe, la percepción de la opinión publica-publicada; o simplemente la conveniencia estratégica. Panamá ha lanzado recientemente una propuesta para incluir la tintorera, quenlla o tiburón azul (Prionace glauca) dentro de la lista de especies del apéndice II de CITES.Postprin

Standardized catch rates of shortfin mako (isurus oxyrinchus) caught by the spanish surface longline fishery targeting swordfish in the indian ocean during the period 2001-2018

Standardized catches per unit of effort in number and weight were obtained for the shortfin mako (Isurus oxyrinchus) using General Linear Modeling procedures based on trip data from the Spanish surface longline fleet targeting swordfish in the Indian Ocean over the period 2001-2018. Factors such as area, quarter, gear and bait, as well as the fishing strategy were taken into account. The model explained 31% and 24% of CPUE variability in number and weight, respectivel

UPDATED STANDARDIZED CATCH RATES IN BIOMASS FOR THE BLUE SHARK (PRIONACE GLAUCA) CAUGHT BY THE SPANISH SURFACE LONGLINE FLEET IN THE INDIAN OCEAN DURING THE 2001-2019 PERIOD

This paper provides an update of standardized catch rates in weight of blue shark using a Generalized Linear Model (GLM) from a total of 2,301 trips carried out by the Spanish surface longline fleet targeting swordfish in the Indian Ocean during the 2001-2019 period. The criteria used to define explanatory variables were similar to those used in previous papers. The main factors considered in the analysis were year, quarter, area, ratio, gear and the interaction quarter*area. The results indicate that the ratio factor (an indicator of target criteria of the skippers) defined as the ratio between the two most prevalent species caught -swordfish and blue shark- was the most important factor which explained the CPUE variability. The GLM results explained 80% of CPUE variability in weight. The index showed a stable trend over time

La crisis de producción y abastecimiento: ¿tarde piamos?

Leemos estos días sobre la preocupación de algunos países de la UE por emprender políticas para asegurar la producción y el abastecimiento de alimento