Tolerancia a la salinidad aguda de gasterópodos dulceacuícolas nativos e introducidos en Tabasco, México

Background. The increase of salinity in continental ecosystems is a factor influencing organisms distribution, abundance, and development. Understanding how tolerance to environmental stress varies among populations helps to predict the effects of climate change on species locally adapted to their abiotic environment. Goals. Assess the effect of salinity on 4 native and 2 introduced gastropod species in Tabasco, by means of their LC50 and LC90, and LT50 and LT90. Methods. Salinity concentrations from 0-15 g/L were tested to determine LC50 and LC90 and tolerance ranges to acute salinity in 4 native and 2 introduced gastropods. Each concentration had 3 replicates with a control and 20 gastropods in each one. Mortality was quantified every hour up to 12 hours. The number of active mollusks was used as a salinity tolerance index. Results. Aroapyrgus clenchi ? 0.30 g/L and Pyrgophorus coronatus ? 1.00 g/L were the least tolerant species, while Pomacea flagellata, Tarebia granifera, and Melanoides tuberculata ? 5 g/L and Mexinauta impluviata ? 6 g/L were the most tolerant. Correlation between concentration and lethal time was inverse and significant. Conclusions. For the introduced species Tarebia granifera and Melanoides tuberculata, acute tolerance to salinity was not significantly different than Mexinauta impluviata and Pomacea flagellata; whereas all 4 were significantly different than Pyrgophorus coronatus and Aroapyrgus clenchi that are less tolerant to salinity.Antecedentes. El aumento de la salinidad en los ecosistemas continentales es uno de los factores que influye en la distribución, abundancia y desarrollo de los organismos. Entender cómo varía la tolerancia al estrés ambiental entre poblaciones sirve para predecir los efectos del cambio climático en especies localmente adaptadas a su ambiente abiótico. Objetivos. Evaluar el efecto de la salinidad en cuatro especies de gasterópodos nativos y dos introducidos por medio de su CL50 y CL90, y TL50 y TL90 en el estado de Tabasco. Métodos. A fin de calcular CL50, CL90 y los rangos de tolerancia aguda a la salinidad de dichas especies, se probaron concentraciones de 0 a 15 g/L. Se utilizaron tres réplicas y un testigo para cada una con 20 gasterópodos por réplica. La mortalidad se contabilizó cada hora hasta las 12 horas. Se utilizó el número de moluscos activos como un índice de tolerancia a la salinidad. Resultados. Las especies que registraron el menor rango de tolerancia fueron Aroapyrgus clenchi ? 0.30 g/L, Pyrgophorus coronatus ? 1.00 g/L y las de mayor rango fueron Pomacea flagellata, Tarebia granifera y Melanoides tuberculata ? 5 g/L Mexinauta impluviata ? 6 g/L. Se encontró una correlación inversa y significativa entre la concentración y el tiempo letal. Conclusiones. La tolerancia aguda a la salinidad entre las especies introducidas Tarebia granifera y Melanoides tuberculata no mostró diferencias importantes con Mexinauta impluviata y Pomacea flagellata, pero sí con Pyrgophorus coronatus y Aroapyrgus clenchi, que presentaron una tolerancia menor

Características del paisaje y su relación con la diversidad y estructura de la vegetación ribereña del sureste de México

Background and Aims: Land use change generated by human activities has fragmented riparian corridors causing changes in the diversity and structure of its vegetation. The objective of this study was to compare the diversity, structure and floristic similarity in five sites of the Tacotalpa River, Tabasco, Mexico, related to vegetation variables with landscape metrics.Methods: Sampling was performed at five sites of the Tacotalpa River: Tapijulapa (s1), Arroyo Chispa (s2), Nuevo Madero (s3), Mexiquito (s4) and Oxolotán (s5). At each site, 20 sampling units of 10 × 10 m were established. Trees and shrubs with a DBH ≥1 cm were counted. The diversity and structure were compared with a one-way ANOVA. The floristic similarity between sites was compared with a Bray-Curtis cluster, Pearson correlation and PCA between vegetation variables and landscape metrics, using PAST and SPSS.Key results: There were 2589 individuals in 38 families, 92 genera and 119 species. The diversity 0D of s2 was statistically lower than s1 and s3, while 1D was similar in the five sites. The tree density of s1 was significantly greater than in s2, s3 and s5. The averages of DHB and height of s1 were low, showing significance with s2 (p <0.05). The floristic similarity ranged from 0.41 to 0.58. Order 0D diversity, shrub species and tree density correlated positively with some of the landscape metrics. The 1D diversity and tree species correlated positively with the paved road distance, and height with the dirt road.Conclusions: The differences between the sites suggest that there are different levels of disturbance along the Tacotalpa River. Positive correlations between vegetation variables and landscape metrics indicate that infrastructures near the river modify the diversity and structure of the riparian vegetation.Antecedentes y Objetivos: El cambio de uso del suelo generado por actividades humanas, ha fragmentado los corredores ribereños causando cambios en la diversidad y estructura de su vegetación. El objetivo de este estudio fue comparar la diversidad, estructura y similitud florística en cinco sitios del río Tacotalpa en Tabasco, México, relacionando las variables de vegetación con métricas del paisaje.Métodos: Se realizó un muestreo en cinco sitios del río Tacotalpa: Tapijulapa (s1), Arroyo Chispa (s2), Nuevo Madero (s3), Mexiquito (s4) y Oxolotán (s5). En cada sitio se establecieron 20 unidades de muestreo de 10 × 10 m. Los árboles y arbustos con un DAP≥1 cm fueron censados. La diversidad y estructura se comparó con un ANOVA de un factor. La similitud florística entre sitios se comparó con un cluster Bray-Curtis correlación de Pearson y ACP entre las variables de vegetación y métricas del paisaje, usando PAST y SPSS.Resultados clave: Se registraron 2589 individuos en 38 familias, 92 géneros y 119 especies. La diversidad 0D del s2 fue estadísticamente menor que en s1 y s3, mientras que 1D fue similar en los cinco sitios. La densidad de árboles del s1 fue significativamente mayor que s2, s3 y s5. Los promedios del DAP y altura del s1 fueron bajos, mostrando significancia con el s2 (p<0.05). La similitud florística osciló entre 0.41 a 0.58. La diversidad orden 0D, las especies arbustivas y la densidad de árboles se correlacionaron positivamente con algunas de las métricas del paisaje. La diversidad 1D y especies arbóreas se correlacionaron positivamente con la distancia de carretera pavimentada, y la altura con la de terracería.Conclusiones: Las diferencias entre los sitios sugieren que existen diferentes niveles de perturbación en el río Tacotalpa. Las correlaciones positivas entre las variables de vegetación y métricas del paisaje indican que las infraestructuras cercanas a la ribera modifican la diversidad y estructura de la vegetación ribereña.

PROSPECÇÃO TECNOLÓGICA SOBRE MORINGA OLEÍFERA APLICADA À CIÊNCIA E TECNOLOGIA DE ALIMENTOS

A Moringa oleifera Lam. é uma espécie arbórea originária do noroeste indiano, cultivada graças ao seu valor alimentar, alto teor proteico, usos na medicina tradicional, indústria e tratamento de água para o consumo humano. Por apresentar tais características, a moringa tem um grande potencial para cultivo comercial. As características de adaptação climática e de solo da planta a tornam implementável como cultivo tanto em escala industrial quanto de subsistência em grandes extensões do território brasileiro. O presente trabalho objetivou avaliar os resultados de pesquisa relativos às aplicações da moringa na tecnologia de alimentos através de pedidos de patentes. Utilizou-se as bases World Intellectual Property Organization (WIPO), Instituto Nacional de Propriedade Industrial (INPI) e European Patent Office (Espacenet). O período coberto por esta pesquisa baseia-se no período máximo permitido por cada base de dado consultada, e é corrente ao mês de outubro de 2013

PROSPECÇÃO TECNOLÓGICA SOBRE Jatropha curcas L.

Este trabalho apresenta um mapeamento tecnológico sobre as potencialidades da Jatropha curcas L. tanto como fonte energética, considerando a grande busca por novas fontes alternativas de energia que se baseiam no uso desta oleaginosa como biomassa, através de busca por pedidos de patentes. Para a realização da pesquisa, utilizaram-se as bases World Intellectual Property Organization (WIPO), o banco de dados do Instituto Nacional de Propriedade Industrial (INPI) e a European Patent Office (Espacenet). Esta prospecção teve o intuito de avaliar e contribuir com o conhecimento sobre as tecnologias já desenvolvidas, identificando os trabalhos na área de uso, caracterização, possíveis aplicações e potenciais da Jatropha curcas L. Assim, foi possível analisar as potencialidades e a evolução das competências tecnológicas traduzidas através dos depósitos de patentes. O período coberto por esta pesquisa baseia-se no período máximo permitido por cada base de dados consultada, sendo corrente ao mês de outubro de 2013

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus

Background: American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, andmay have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. Methodology/Principal Findings: We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. Conclusions/Significance: Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental condition