Phylogenetic congruence of mealybugs and their primary endosymbionts

Tight interactions between unrelated organisms such as is seen in plant–insect, host–parasite, or host–symbiont associations may lead to speciation of the smaller partners when their hosts speciate. Totally congruent phylogenies of interacting taxa have not been observed often but a number of studies have provided evidence that various hemipteran insect taxa and their primary bacterial endosymbionts share phylogenetic histories. Like other hemipterans, mealybugs (Pseudococcidae) harbour multiple intracellular bacterial symbionts, which are thought to be strictly vertically inherited, implying codivergence of hosts and symbionts. Here, robust estimates of phylogeny were generated from four fragments of three nuclear genes for mealybugs of the subfamily Pseudococcinae, and a substantial fragment of the 16S–23S rDNA of their P-endosymbionts. Phylogenetic congruence was highly significant, with 75% of nodes on the two trees identical, and significant correlation of branch lengths indicated coincident timing of cladogenesis. It is suggested that the low level of observed incongruence was influenced by uncertainty in phylogenetic estimation, but evolutionary outcomes other than congruence, including host shifts, could not be rejected

Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution

BACKGROUND: Integration of diverse data (molecules, fossils) provides the most robust test of the phylogeny of cetaceans. Positioning key fossils is critical for reconstructing the character change from life on land to life in the water. METHODOLOGY/PRINCIPAL FINDINGS: We reexamine relationships of critical extinct taxa that impact our understanding of the origin of Cetacea. We do this in the context of the largest total evidence analysis of morphological and molecular information for Artiodactyla (661 phenotypic characters and 46,587 molecular characters, coded for 33 extant and 48 extinct taxa). We score morphological data for Carnivoramorpha, Creodonta, Lipotyphla, and the raoellid artiodactylan Indohyus and concentrate on determining which fossils are positioned along stem lineages to major artiodactylan crown clades. Shortest trees place Cetacea within Artiodactyla and close to Indohyus, with Mesonychia outside of Artiodactyla. The relationships of Mesonychia and Indohyus are highly unstable, however--in trees only two steps longer than minimum length, Mesonychia falls inside Artiodactyla and displaces Indohyus from a position close to Cetacea. Trees based only on data that fossilize continue to show the classic arrangement of relationships within Artiodactyla with Cetacea grouping outside the clade, a signal incongruent with the molecular data that dominate the total evidence result. CONCLUSIONS/SIGNIFICANCE: Integration of new fossil material of Indohyus impacts placement of another extinct clade Mesonychia, pushing it much farther down the tree. The phylogenetic position of Indohyus suggests that the cetacean stem lineage included herbivorous and carnivorous aquatic species. We also conclude that extinct members of Cetancodonta (whales+hippopotamids) shared a derived ability to hear underwater sounds, even though several cetancodontans lack a pachyostotic auditory bulla. We revise the taxonomy of living and extinct artiodactylans and propose explicit node and stem-based definitions for the ingroup

Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists

The Current Status of Research on the Integration of Sexual and Reproductive Health and HIV Services.

Integration of services for sexual and reproductive health (SRH) and HIV has been widely promoted globally in the belief that both clients and health providers benefit through improvements in quality, efficient use of resources, and lower costs, helping to maximize limited health resources and provide comprehensive client-centered care. This article builds on the growing body of research on integrated sexual SRH and HIV services. It brings together critical reviews on issues within the wider SRH and rights agenda and synthesizes recent research on integrated services, drawing on the Integra Initiative and other major research. Unintended pregnancy and HIV are intrinsically interrelated SRH issues, however broadening the constellation of services, scaling up, and mainstreaming integration continue to be challenging. Overcoming stigma, reducing gender-based violence, and meeting key populations' SRH needs are critical. Health systems research using SRH as the entry point for integrated services and interaction with communities and clients is needed to realize universal health coverage

Farmers’ attitudes and perceptions of adoption of agricultural innovations in Kenya: a mixed methods analysis

Attitudes and perceptions are key constructs in decision making. Their nature and influence on agricultural technology adoption among smallholder farmers in Kenya has not been adequately researched. The research applied a mixed methods approach to assess the influence of attitudes and perceptions in adoption of agricultural innovations by smallholder farmers in Kenya. The quantitative phase used a survey (n=245) while the qualitative consisted of focus groups (n=28) to elicit subjective farmer views of innovations. A principal component analysis (PCA) technique reduced 14-attitudes statements to five conceptual clusters: challenges in accessing agricultural innovations (explained 19.09% of the total variance); effectiveness of agricultural technologies (11.88%); enjoyment of agricultural technologies (10.02%); social influence in use of technology (9.47%); and experience with agricultural technologies (8.13%). Qualitative analysis identified key themes: farmer ambivalence about innovations; economic benefits of innovation use; ease of use of technology encouraged adoption; lack of trust; and limited knowledge of innovations. Farmers' positive evaluation of technology did not encourage widespread adoption of innovations. Farmers were found to be poorly equipped to use innovations due to limited access to agricultural information and training supporting the use of innovations. The absence of trust between the farmers and extension agents aggravated the situation

Les détergents et les désinfectants : rôle en médecine (1re partie)

International audienceRésumé Objectifs: Faire le point sur le rôle des détergents et désinfectants en médecine. Les produits: Les détergents, désinfectants (y compris les antiseptiques) sont des produits chimiques. Ils sont soumis à l'évolution constante des réglementations qui veillent à privilégier des produits présentant le meilleur rapport bénéfice/risques tant pour l'homme que pour l'environnement. Mode d'action: Les détergents agissent sur les salissures alors que les désinfectants agissent sur les micro-organismes. Les modes d'action sont complexes et varient en fonction de nombreux paramètres. La plupart des désinfectants ou des antiseptiques sont inhibés par les matières organiques, ce qui rend le préalable de la détergence indispensable à leur utilisation. Utilisation en médecine: Les détergents et les désinfectants sont des produits largement utilisés dans de nombreuses applications concernant les objets inertes ou la peau. Ils sont utilisés en médecine que ce soit en curatif ou en préventif pour l'homme ou son environnement