RinA controls phage-mediated packaging and transfer of virulence genes in gram-positive bacteria

Phage-mediated transfer of microbial genetic elements plays a crucial role in bacterial life style and evolution. In this study, we identify the RinA family of phage-encoded proteins as activators required for transcription of the late operon in a large group of temperate staphylococcal phages. RinA binds to a tightly regulated promoter region, situated upstream of the terS gene, that controls expression of the morphogenetic and lysis modules of the phage, activating their transcription. As expected, rinA deletion eliminated formation of functional phage particles and significantly decreased the transfer of phage and pathogenicity island encoded virulence factors. A genetic analysis of the late promoter region showed that a fragment of 272 bp contains both the promoter and the region necessary for activation by RinA. In addition, we demonstrated that RinA is the only phage-encoded protein required for the activation of this promoter region. This region was shown to be divergent among different phages. Consequently, phages with divergent promoter regions carried allelic variants of the RinA protein, which specifically recognize its own promoter sequence. Finally, most Gram-postive bacteria carry bacteriophages encoding RinA homologue proteins. Characterization of several of these proteins demonstrated that control by RinA of the phage-mediated packaging and transfer of virulence factor is a conserved mechanism regulating horizontal gene transfer.

Prioritization of knowledge needs for sustainable aquaculture: a national and global perspective

Aquaculture is currently the fastest expanding global animal food production sector and is a key future contributor to food security. An increase in food security will be dependent upon the development and improvement of sustainable practices. A prioritization exercise was undertaken, focusing on the future knowledge needs to underpin UK sustainable aquaculture (both domestic and imported products) using a ‘task force’ group of 36 ‘practitioners’ and 12 ‘research scientists’ who have an active interest in sustainable aquaculture. A long list of 264 knowledge needs related to sustainable aquaculture was developed in conjunction with the task force. The long list was further refined through a three stage process of voting and scoring, including discussions of each knowledge need. The top 25 knowledge needs are presented, as scored separately by ‘practitioners’ or ‘research scientists’. There was similar agreement in priorities identified by these two groups. The priority knowledge needs will provide guidance to structure ongoing work to make science accessible to practitioners and help to prioritize future science policy needs and funding. The process of knowledge exchange, and the mechanisms by which this can be achieved, effectively emerged as the top priority for sustainable aquaculture. Viable alternatives to wild fish-based aquaculture feeds, resource constraints that will potentially limit expansion of aquaculture, sustainable offshore aquaculture and the treatment of sea lice also emerged as strong priorities. Although the exercise was focused on UK needs for sustainable aquaculture, many of the emergent issues are considered to have global application.

The transfer of energy between electrons and ions in solids

In this review we consider those processes in condensed matter that involve the irreversible flow of energy between electrons and nuclei that follows from a system being taken out of equilibrium. We survey some of the more important experimental phenomena associated with these processes, followed by a number of theoretical techniques for studying them. The techniques considered are those that can be applied to systems containing many nonequivalent atoms. They include both perturbative approaches (Fermi's Golden Rule and non-equilibrium Green's functions) and molecular dynamics based (the Ehrenfest approximation, surface hopping, semi-classical Gaussian wavefunction methods and correlated electron-ion dynamics). These methods are described and characterized, with indications of their relative merits.

Practicum in Educational Psychology: comparative analysis between areas of knowledge

In this paper we present the process and results of an investigation in which, after reflecting on the concept of Practicum and, specifically, in the Practicum in Educational Psychology degree taught at the University of A Coruña, an assessment is made taking into account the opinion of the students who have studied this matter, as to the relevance that the planned objectives are given and subsequent achievement of these. The results differ considering the area that the teacher who has tutored belongs to. Methodologicaly, it is a descriptive research, survey type, which involved a significant sample of students in their final year of the degree in the year 2012/13 through a questionnaire which validity (Teaching and content) and reliability (internal consistency) have been properly set (judgment of experts and a pilot experience for the calculation of Cronbach's alpha). The results show that the Practicum program has a good development of most of the objectives, especially those related to skills, where the average of the highest rated goals exceed the rating of 4. This suggests clear lines for innovation and improvement in the areas of conceptual and attitudinal level.