84 research outputs found
Cluster M Mycobacteriophages Bongo, PegLeg, and Rey with Unusually Large Repertoires of tRNA Isotopes
Genomic analysis of a large set of phages infecting the common hostMycobacterium smegmatis mc2155 shows that they span considerable genetic diversity. There are more than 20 distinct types that lack nucleotide similarity with each other, and there is considerable diversity within most of the groups. Three newly isolated temperate mycobacteriophages, Bongo, PegLeg, and Rey, constitute a new group (cluster M), with the closely related phages Bongo and PegLeg forming subcluster M1 and the more distantly related Rey forming subcluster M2. The cluster M mycobacteriophages have siphoviral morphologies with unusually long tails, are homoimmune, and have larger than average genomes (80.2 to 83.7 kbp). They exhibit a variety of features not previously described in other mycobacteriophages, including noncanonical genome architectures and several unusual sets of conserved repeated sequences suggesting novel regulatory systems for both transcription and translation. In addition to containing transfer-messenger RNA and RtcB-like RNA ligase genes, their genomes encode 21 to 24 tRNA genes encompassing complete or nearly complete sets of isotypes. We predict that these tRNAs are used in late lytic growth, likely compensating for the degradation or inadequacy of host tRNAs. They may represent a complete set of tRNAs necessary for late lytic growth, especially when taken together with the apparent lack of codons in the same late genes that correspond to tRNAs that the genomes of the phages do not obviously encode
Drinking behaviours and blood alcohol concentration in four European drinking environments: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Reducing harm in drinking environments is a growing priority for European alcohol policy yet few studies have explored nightlife drinking behaviours. This study examines alcohol consumption and blood alcohol concentration (BAC) in drinking environments in four European cities.</p> <p>Methods</p> <p>A short questionnaire was implemented among 838 drinkers aged 16-35 in drinking environments in four European cities, in the Netherlands, Slovenia, Spain and the UK. Questions included self-reported alcohol use before interview and expected consumption over the remainder of the night. Breathalyser tests were used to measured breath alcohol concentration (converted to BAC) at interview.</p> <p>Results</p> <p>Most participants in the Dutch (56.2%), Spanish (59.6%) and British (61.4%) samples had preloaded (cf Slovenia 34.8%). In those drinking < 3 h at interview, there were no differences in BAC by gender or nationality. In UK participants, BAC increased significantly in those who had been drinking longer, reaching 0.13% (median) in females and 0.17% in males drinking > 5 h. In other nationalities, BAC increases were less pronounced or absent. High BAC (> 0.08%) was associated with being male, aged > 19, British and having consumed spirits. In all cities most participants intended to drink enough alcohol to constitute binge drinking.</p> <p>Conclusions</p> <p>Different models of drinking behaviour are seen in different nightlife settings. Here, the UK sample was typified by continued increases in inebriation compared with steady, more moderate intoxication elsewhere. With the former being associated with higher health risks, European alcohol policy must work to deter this form of nightlife.</p
The national burden of road traffic injuries in Thailand
Background: This study quantifies the burden of road traffic injuries (RTIs) in Thailand in 2004, incorporating new Thai data on mortality and the frequency and severity of long-term disability
Cluster K Mycobacteriophages: Insights into the Evolutionary Origins of Mycobacteriophage TM4
Five newly isolated mycobacteriophages âAngelica, CrimD, Adephagia, Anaya, and Pixie â have similar genomic architectures to mycobacteriophage TM4, a previously characterized phage that is widely used in mycobacterial genetics. The nucleotide sequence similarities warrant grouping these into Cluster K, with subdivision into three subclusters: K1, K2, and K3. Although the overall genome architectures of these phages are similar, TM4 appears to have lost at least two segments of its genome, a central region containing the integration apparatus, and a segment at the right end. This suggests that TM4 is a recent derivative of a temperate parent, resolving a long-standing conundrum about its biology, in that it was reportedly recovered from a lysogenic strain of Mycobacterium avium, but it is not capable of forming lysogens in any mycobacterial host. Like TM4, all of the Cluster K phages infect both fast- and slow-growing mycobacteria, and all of them â with the exception of TM4 â form stable lysogens in both Mycobacterium smegmatis and Mycobacterium tuberculosis; immunity assays show that all five of these phages share the same immune specificity. TM4 infects these lysogens suggesting that it was either derived from a heteroimmune temperate parent or that it has acquired a virulent phenotype. We have also characterized a widely-used conditionally replicating derivative of TM4 and identified mutations conferring the temperature-sensitive phenotype. All of the Cluster K phages contain a series of well conserved 13 bp repeats associated with the translation initiation sites of a subset of the genes; approximately one half of these contain an additional sequence feature composed of imperfectly conserved 17 bp inverted repeats separated by a variable spacer. The K1 phages integrate into the host tmRNA and the Cluster K phages represent potential new tools for the genetics of M. tuberculosis and related species
A Broadly Implementable Research Course in Phage Discovery and Genomics for First-Year Undergraduate Students
Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over 4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of phage genomics but also stimulates studentsâ interest in science, positively influences academic achievement, and enhances persistence in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science education and research training
A model of management academics' intentions to influence values
Business schools face increased criticism for failing in the teaching of management studies to nurture their studentsâ values. Assuming that individual academics play an important role in shaping the value-related influence of business schools, I model management academicsâ intentions to influence values. The suggested model encompasses academicsâ economic and social values as internal variables, as well as perceived support for attempting to influence values and academic tenure as social and structural variables. A test with empirical data from 1,254 management academics worldwide reveals that perceived external support is most relevant for explaining intentions. Moreover, academicsâ social values, but not their economic ones, contribute to an explanation of their intentions to influence values. The results reveal how important it is for academics to believe that their colleagues, higher education institutions, and other stakeholders support their value-related behavioral intentions
A Broadly Implementable Research Course in Phage Discovery and Genomics for First-Year Undergraduate Students
Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over 4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of phage genomics but also stimulates studentsâ interest in science, positively influences academic achievement, and enhances persistence in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science education and research training
Recommended from our members
A Broadly Implementable Research Course in Phage Discovery and Genomics for First-Year Undergraduate Students
Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We
have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a
research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated
within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with
established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters
Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over
4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of
phage genomics but also stimulates studentsâ interest in science, positively influences academic achievement, and enhances persistence
in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating
other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science
education and research training.
IMPORTANCE: Engagement of undergraduate students in scientific research at early stages in their careers presents an opportunity
to excite students about science, technology, engineering, and mathematics (STEM) disciplines and promote continued interests
in these areas. Many excellent course-based undergraduate research experiences have been developed, but scaling these to a
broader impact with larger numbers of students is challenging. The Howard Hughes Medical Institute (HHMI) Science Education
Alliance Phage Hunting Advancing Genomics and Evolutionary Science (SEA-PHAGES) program takes advantage of the
huge size and diversity of the bacteriophage population to engage students in discovery of new viruses, genome annotation, and
comparative genomics, with strong impacts on bacteriophage research, increased persistence in STEM fields, and student selfidentification
with learning gains, motivation, attitude, and career aspirations
- âŠ