Spiders do not escape reproductive manipulations by Wolbachia

<p>Abstract</p> <p>Background</p> <p>Maternally inherited bacteria that reside obligatorily or facultatively in arthropods can increase their prevalence in the population by altering their hosts' reproduction. Such reproductive manipulations have been reported from the major arthropod groups such as insects (in particular hymenopterans, butterflies, dipterans and beetles), crustaceans (isopods) and mites. Despite the observation that endosymbiont bacteria are frequently encountered in spiders and that the sex ratio of particular spider species is strongly female biased, a direct relationship between bacterial infection and sex ratio variation has not yet been demonstrated for this arthropod order.</p> <p>Results</p> <p>Females of the dwarf spider <it>Oedothorax gibbosus </it>exhibit considerable variation in the sex ratio of their clutches and were infected with at least three different endosymbiont bacteria capable of altering host reproduction i.e. <it>Wolbachia</it>, <it>Rickettsia </it>and <it>Cardinium</it>. Breeding experiments show that sex ratio variation in this species is primarily maternally inherited and that removal of the bacteria by antibiotics restores an unbiased sex ratio. Moreover, clutches of females infected with <it>Wolbachia </it>were significantly female biased while uninfected females showed an even sex ratio. As female biased clutches were of significantly smaller size compared to non-distorted clutches, killing of male embryos appears to be the most likely manipulative effect.</p> <p>Conclusions</p> <p>This represents to our knowledge the first direct evidence that endosymbiont bacteria, and in particular <it>Wolbachia</it>, might induce sex ratio variation in spiders. These findings are pivotal to further understand the diversity of reproductive phenotypes observed in this arthropod order.</p

Comunidades de práctica e innovación: aprender a emprender en el área de Bibliotecología y Ciencias de la Documentación

ResumenEl propósito del trabajo es ofrecer directrices teóricas y metodológicas para diseñar, crear y desarrollar Comunidades de Práctica (CoP) en el área de la Bibliotecología y las Ciencias de la Documentación. Las CoP presentan la posibilidad de integrar en un mismo entorno o comunidad a miembros con objetivos comunes que buscan beneficiarse de la generación de conocimientos compartidos. En este contexto de desarrollo se presenta un caso real, circunscrito en el marco de un proyecto de innovación educativa, con alumnos del Máster en Gestión de la Documentación, Bibliotecas y Archivos de la Facultad de Ciencias de la Documentación de la Universidad Complutense de Madrid (España). Dicho caso ofrece una perspectiva de uso efectivo de una CoP aportando un escenario o red de intercambio de conocimiento común, que sirve de apoyo al aprendizaje educativo y cuya finalidad principal es fomentar la cultura innovadora y emprendedora entre todos sus participantes.AbstractThis study aims to provide guidelines for designing, creating and developing a Community of Practice (CoP) in the area Library and Documentation Science. Such a CoP offers the potential of bringing together persons with shared interests and objectives who can reap real benefits through the generation of shared knowledge. The paper presents a case study involving an educational project with master degree candidates in the Documentation, Libraries and Archives Management of the Faculty of the Documentary Science of the Universidad Complutense de Madrid (Spain). This case provides a view of the effective use of CoP, which constitutes a scenario or network for exchange of shared knowledge, while underpinning educational learning and promoting the culture of innovation and enterprise among the members of the community

Individual and environmental factors influencing adolescents’ dietary behavior in low- and middle-income settings

PRIFPRI3; ISIPHN

Participant characteristics.

Participant characteristics.</p

Specification of a SEM for predicting dietary behavior, including mediation effects.

<p>Rectangles indicate observed variables, and ellipses latent variables. HE: Healthy Eating.</p

Conceptual framework for healthy dietary behavior in an Ecuadorian population.

<p>Conceptual framework for healthy dietary behavior in an Ecuadorian population.</p

Cronbach’s alpha and Intra-class Correlation Coefficient for retained constructs in the model at individual and environmental level.

<p>Cronbach’s alpha and Intra-class Correlation Coefficient for retained constructs in the model at individual and environmental level.</p

Individual and Environmental Factors Influencing Adolescents’ Dietary Behavior in Low- and Middle-Income Settings - Fig 3

<p>(A) Individual and environmental influences on sugary drink consumption. Only statistically significant paths at P < 0.05 are shown. Goodness of Fit-statistics: χ²(303) = 630.18, p< 0.001; RMSEA = 0.038; NNFI = 0.92; CFI = 0.93, GFI = 0.93. HE: Healthy Eating. (B) Individual and environmental influences on breakfast consumption. Only statistically significant paths at P < 0.05 are shown. Goodness of Fit-statistics: χ²(303) = 630.50, p< 0.001; RMSEA = 0.038; NNFI = 0.92; CFI = 0.93, GFI = 0.94. HE: Healthy Eating. (C) Individual and environmental influences on fruit, vegetable and fruit and vegetable consumption. Only statistically significant paths at P < 0.05 are shown. Goodness of Fit-statistics: χ²(303) = 623.69, p< 0.001; RMSEA = 0.038; NNFI = 0.92; CFI = 0.93, GFI = 0.94. ^a significant pathway for vegetable intake only. HE: Healthy Eating(D) Individual and environmental influences on unhealthy snacking. Only statistically significant paths at P < 0.05 are shown. Goodness of Fit-statistics: χ²(303) = 619.19, p< 0.001; RMSEA = 0.037; NNFI = 0.92; CFI = 0.93, GFI = 0.94. HE: Healthy Eating.</p

Key components of dietary behaviour as measured by two 24h dietary recalls.

<p>Key components of dietary behaviour as measured by two 24h dietary recalls.</p