Cutting edge: Regulation of exosome secretion by the integral MAL protein in T cells

Exosomes secreted by T cells play an important role in coordinating the immune response. HIV-1 Nef hijacks the route of exosome secretion of T cells to modulate the functioning of uninfected cells. Despite the importance of the process, the protein machinery involved in exosome biogenesis is yet to be identified. In this study, we show that MAL, a tetraspanning membrane protein expressed in human T cells, is present in endosomes that travel toward the plasma membrane for exosome secretion. In the absence of MAL, the release of exosome particles and markers was greatly impaired. This effect was accompanied by protein sorting defects at multivesicular endosomes that divert the exosomal marker CD63 to autophagic vacuoles. Exosome release induced by HIV-1 Nef was also dependent on MAL expression. Therefore,MAL is a critical element of the machinery for exosome secretion andmay constitute a target for modulating exosome secretion by human T cells. The Journal of Immunology, 2015, 195: 810–814.Peer Reviewe

Morphological Variations of Wild Populations of Brycon dentex (Characidae, Teleostei) in the Guayas Hydrographic Basin (Ecuador). The Impact of Fishing Policies and Environmental Conditions

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance

Usefulness of Discriminant Analysis in the Morphometric Differentiation of Six Native Freshwater Species from Ecuador

The aim of this research was to find out the morphometric differentiation of six native freshwater species in the Guayas Hydrographic Basin (Ecuador) by means of discriminant analysis. A total of 1355 mature fishes (Cichlasoma festae, Andinoacara rivulatus, Dormitator latifrons, Bryncon dentex, Hoplias microlepis and Leporinus ecuadorensis) were captured and 27 morphometric measurements and 20 landmarks were used. Two-way analysis of variance with species and sex as fixed factors and discriminant analysis were applied. The selection of the most discriminant variables was made applying the F of Snedecor, Wilks’-Lambda and the 1-Tolerance. While sex within species had no significant effect on the morphology, differences among species were significant. Twenty-seven morphological variables showed highly significant differences among six native freshwater species. Nine biometric variables with high discriminant power were selected. The six species analyzed were discriminated by the morphometric models generated, thus showing that discriminant analysis was useful for differentiating species. The morphometric differentiation by discriminant analysis is a direct, simple and economic methodology to be applied in situ in rural communities. It favors the implementation of a livestock development program and it could be used with other native freshwater species in the Guayas Hydrographic Basin

BioExtreme workshop, O Rosal (Galicia, España), verano 2018

La concentración de gases de efecto invernadero en la atmósfera aumenta anualmente debido, principalmente, al uso generalizado de combustibles fósiles como fuente de energía. Este incremento está detrás de una serie de cambios a nivel planetario en parámetros tan importantes como el clima (ej. cambios en el rango de temperaturas y precipitaciones globales) o los niveles de salinidad y pH de los océanos, con importantes implicaciones para la biodiversidad. Existe también un aumento en la disponibilidad de bases de datos y modelos climáticos (ej. MERRAClim, WorldClim, CHELSA, ENVIREM, CliMond, AquaMaps, Bio-ORACLE) que sirven para estimar futuros escenarios de cambio climático y escenarios del pasado reciente, como el último máximo glaciar o el Holoceno medio (ej. ecoClimate, PaleoClim, etc.). Estos modelos suelen proporcionar valores medios de temperatura (ej. temperatura media anual, temperatura media del trimestre más frío o más cálido, etc.) y valores agregados de precipitación (ej. precipitación anual, precipitación del trimestre más seco o más húmedo, etc.). Tradicionalmente, la mayoría de los estudios científicos enfocados en entender los efectos del cambio climático sobre los ecosistemas han utilizado este tipo de variables. Sin embargo, cada vez es más patente que otro tipo de parámetros del clima, como valores extremos de temperatura o precipitación, pueden afectar de manera importante a las especies y sus hábitats. El pasado verano se organizó en O Rosal (Galicia, España) (Fig.1) un workshop interdisciplinar al que acudieron especialistas en biogeografía, macroecología, herpetología, mastozoología, ecología del suelo y oceanografía con el objetivo de discutir sobre qué tipos de extremos climáticos pueden tener una mayor influencia en el funcionamiento de los ecosistemas y la distribución de los organismos. Como resultado de esta reunión se seleccionaron un conjunto de variables climáticas altamente relevantes a nivel ecológico tanto para el medio marino como para el medio terrestre, y las cuales tienen en cuenta la intensidad y duración de los eventos climáticos extremos

Fatores que afetam o valor nutritivo da silagens de forrageiras tropicais

Considering the importance of silage as alternative for animal feeding systems, this review aims to present recent results available in literature on factors affecting the nutritive value of silage, especially in tropical forages. Considering the cost of feed, the use of silage as animal feed is an important practice in the sustainability of production systems, especially in dry periods of the year. The ensiling of by-products of industry may be an important tool to reduce the dependence on external inputs, and reduce the environmental contamination by these residues. Changes and losses during ensilage are influenced by the characteristics of the fodder plant and are also associated with management, harvesting and storage practices. The factors that influence the process of ensilage are numerous and act alone or interact with each other, which should be considered to obtain silage of higher quality and more stable. In relation with the application of, enzymatic additives or its association with inoculants, in tropical forage, the results available in the literature are controversial and dependent on local conditions, concentration and type of inoculum, method of application, quality of forage plant, and present microflora, among other factors.Considerando a importância do uso da ensilagem como alternativa dos sistemas de alimentação animal, essa revisão objetiva apresentar resultados recentes disponíveis na literatura sobre alguns fatores que afetam o valor nutritivo da silagem, notadamente de forrageiras tropicais. A utilização de silagem na alimentação animal é uma prática importante na sustentabilidade dos sistemas produtivos, considerando os custos com alimentação animal, principalmente nos períodos seco do ano. A ensilagem de subprodutos da indústria pode ser uma importante ferramenta para diminuir a dependência de insumos externos, além de diminuir a contaminação ambiental por esses resíduos. As mudanças e perdas durante a ensilagem são influenciadas pelas características da planta forrageira e estão também associadas às práticas de manejo, colheita e armazenamento. Os fatores que influenciam no processo de ensilagem são muitos e agem isoladamente ou interagem entre si, que precisam ser considerados para obtenção de silagem de maior qualidade e mais estáveis. Resultados sobre a aplicação de aditivos enzimáticos ou sua associação com inoculantes em forrageiras tropicais são controversos na literatura disponível e dependentes das condições locais, concentração e tipo de inoculante, método de aplicação, qualidade da planta forrageira, microflora pré-existente, entre outros fatores

Morphometric and Meristic Characterization of Native Chame Fish (Dormitator latifrons) in Ecuador Using Multivariate Analysis

Ecuador, a country exhibiting large developments in fish farming, has a great variety of freshwater native fish. Among these fish is the Dormitator latifrons or chame, which has characteristics that make its farming prone to occur at a quite-developed stage. However, morphological characterization is required to establish a conservation program. In this study, 300 chames were captured in the Manabi province (Ecuador) to analyze their morphostructural model and to evaluate the effects of sex and the production system through multivariant techniques. The fish from the farm presented morphological measurements that were statistically (p 0.05). The percentage of correct adscription was 84%, with larger errors in wild fish. The morphostructural model had a high homogeneity, with 89.95% significant correlations (p < 0.05), and wild male and female fish were more homogeneous. The farm fish were larger because of the higher food availability. Moreover, the species exhibited sexual dimorphism, although there were no great differences in the morphometric measurements. This study shows the great biodiversity that naturally exists in Ecuadorian rivers. Therefore, it is of great interest to develop a chame breeding and conservation program

Is the increase of scale in the tropics a pathway to smallholders? Dimension and ecological zone effect on the mixed crop-livestock farms

Mixed crop-livestock farms are widely spread in different tropical regions in the world; they contribute to food security, rural development, sustainability and poverty alleviation. The effect of scale on performance of dual purpose (DP) cattle farms was evaluated in two Mexican ecological zones: dry (DT) and wet tropics (WT). In 2011, a questionnaire of 184 items distributed into technical and social characteristics was applied to a representative sample of 3,285 farms with 50 or less cows (0.97%). The farms were classified into three groups according to their dimension: very small (1-9 cows), small (10-19 cows) and medium (20-50 cows). A general linear model (GLM) with two factors and their interactions was applied. Significant effects in dimension and ecological zone were found as well as seven interactions between both factors (p&lt;0.05). Native pastures were used in all farms for grazing. However, small farms’ herds frequently grazed on cultivated pastures and on crop residues (p&lt;0.05). Medium farms showed the highest grazing surface, but in the WT silage and green fodder were used while in the DT dry fodders were used (p&lt;0.001). The interactions between factors showed a bigger specialization in milk production in DT farms, whereas WT farms were more specialized in meat production. The mixed crop-livestock system in tropic region requires an increase in herd size according to farm’s own productive structure, which is strongly influenced by the ecological zone. The systems would improve with the active participation of smallholders to identify and achieve best practices, higher technological adoption level and with an effective support from public and private Institutions

The association between diet and sleep quality among Spanish university students

While it has long been recognized that diet is a leading behavioral risk factor for human health, recent scientific findings have also suggested that diet and sleep quality may be connected. The purpose of the present study is to evaluate the association between diet and sleep quality among a group of Spanish university students. To do so, a cross-sectional study of 868 students was carried out. Sleep quality was assessed using the Spanish version of the Pittsburgh Sleep Quality Index (PSQI), while diet was assessed using the Spanish Healthy Eating Index (SHEI). The study revealed a noteworthy rate of bad sleepers (51.6%) and students whose diet needed modifications (82.2%). Unhealthy eaters were more likely to have poor sleep quality (aOR = 4.20; CI 95%: 2.07-8.52). The unbalanced intake of vegetables (aOR = 1.63; CI 95%: 1.14-2.34), fruits (aOR = 4.08; CI 95%: 2.90-5.74), dairy products (aOR = 1.96; CI 95%: 1.41-2.72), lean meats (aOR = 1.82; CI 95%: 1.19-2.78), legumes (aOR = 1.43; CI 95%: 1.00-2.02), sweets (aOR = 1.60; CI 95%: 1.13-2.25) and sugary soft drinks (aOR = 1.46; CI 95%: 1.07-1.99) was associated with lower sleep quality