DNA recognition and transcriptional regulation by the WhiA sporulation factor

Sporulation in the filamentous bacteria Streptomyces coelicolor is a tightly regulated process involving aerial hyphae growth, chromosome segregation, septation and spore maturation. Genetic studies have identified numerous genes that regulate sporulation, including WhiA and the sigma factor WhiG. WhiA, which has been postulated to be a transcriptional regulator, contains two regions typically associated with DNA binding: an N-terminal domain similar to LAGLIDADG homing endonucleases, and a C-terminal helix-turn-helix domain. We characterized several in vitro activities displayed by WhiA. It binds at least two sporulation-specific promoters: its own and that of parABp2. DNA binding is primarily driven by its HTH domain, but requires full-length protein for maximum affinity. WhiA transcription is stimulated by WhiG, while the WhiA protein binds directly to WhiG (leading to inhibition of WhiG-dependent transcription). These separate activities, which resemble a possible feedback loop, may help coordinate the closely timed cessation of aerial growth and subsequent spore formation

Cardiovascular disease by diabetes status in five ethnic minority groups compared to ethnic Norwegians

<p>Abstract</p> <p>Background</p> <p>The population in Norway has become multi-ethnic due to migration from Asia and Africa over the recent decades. The aim of the present study was to explore differences in the self-reported prevalence of cardiovascular disease (CVD) and associated risk factors by diabetes status in five ethnic minority groups compared to ethnic Norwegians.</p> <p>Methods</p> <p>Pooled data from three population-based cross-sectional studies conducted in Oslo between 2000 and 2002 was used. Of 54,473 invited individuals 24,749 (45.4%) participated. The participants self-reported health status, underwent a clinical examination and blood samples were drawn. A total of 17,854 individuals aged 30 to 61 years born in Norway, Sri-Lanka, Pakistan, Iran, Vietnam or Turkey were included in the study. Chi-square tests, one-way ANOVAs, ANCOVAs, multiple and logistic regression were used.</p> <p>Results</p> <p>Age- and gender-standardized prevalence of self-reported CVD varied between 5.8% and 8.2% for the ethnic minority groups, compared to 2.9% among ethnic Norwegians (p < 0.001). Prevalence of self-reported diabetes varied from 3.0% to 15.0% for the ethnic minority groups versus 1.8% for ethnic Norwegians (p < 0.001). Among individuals without diabetes, the CVD prevalence was 6.0% versus 2.6% for ethnic minorities and Norwegians, respectively (p < 0.001). Corresponding CVD prevalence rates among individuals with diabetes were 15.3% vs. 12.6% (p = 0.364). For individuals without diabetes, the odds ratio (OR) for CVD in the ethnic minority groups remained significantly higher (range 1.5-2.6) than ethnic Norwegians (p < 0.05), after adjustment for age, gender, education, employment, and body height, except for Turkish individuals. Regardless of diabetes status, obesity and physical inactivity were prevalent in the majority of ethnic minority groups, whereas systolic- and diastolic- blood pressures were higher in Norwegians. In nearly all ethnic groups, individuals with diabetes had higher triglycerides, waist-to-hip ratio (WHR), and body mass index compared to individuals without diabetes. Age, diabetes, hypertension, hypercholesterolemia, and WHR were significant predictors of CVD in both ethnic Norwegians and ethnic minorities, but significant ethnic differences were found for age, diabetes, and hypercholesterolemia.</p> <p>Conclusions</p> <p>Ethnic differences in the prevalence of CVD were prominent for individuals without diabetes. Primary CVD prevention including identification of undiagnosed diabetes should be prioritized for ethnic minorities without known diabetes.</p

An Estimate of Avian Mortality at Communication Towers in the United States and Canada

Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action

The effects of thoracic manipulation on posteroanterior spinal stiffness

Study Design: Controlled laboratory study, with measurements taken before and after a standardized clinical intervention. Objectives: To determine if thoracic manipulation alters the posteroanterior (PA) spinal stiffness of the thoracic spine, and the factors associated with any potential changes in stiffness. Background: Spinal manipulation is commonly used to treat thoracic pain and dysfunction. Therapists use manual assessment of PA spinal stiffness to determine the appropriateness and effectiveness of treatment, with potential changes in spinal stiffness possibly contributing to symptomatic improvement following manipulation. Methods: Thoracic PA spinal stiffness was measured at 5 vertebral levels (manipulated level and 2 levels above and below), in 24 asymptomatic subjects, before and after manipulation. Five cycles of standardized mechanical PA force were applied to the spinous process while recording resistance to movement and concurrent displacement, with stiffness defined as the slope of the linear portion of the force-displacement curve. A 2-way repeated-measures analysis of variance determined differences between premanipulation and postmanipulation among multiple spinal levels. Linear regression determined the relationship between stiffness magnitude and its change following manipulation. Generalized linear mixed models were used to determine if subject age, gender, spinal level, premanipulation stiffness, or manipulative thrust parameters were associated with postmanipulation stiffness. Results: Thoracic spine PA stiffness differed between spinal levels (F₄,₉₂= 21.1, P<.001) but was not significantly different following manipulation. The mean change in spinal stiffness correlated with stiffness magnitude at the manipulated spinal level only but not other levels (Pearson r, –0.65; P<.001). Greater postmanipulation stiffness was associated with being male (regression coefficient, 1.16; 95% CI: 0.52, 1.79; P<.001) and with higher premanipulation stiffness (regression coefficient, 0.63; 95% CI: 0.49, 0.77; P<.001). Manipulation force parameters were not associated with postmanipulation stiffness. Conclusion: In asymptomatic individuals, thoracic PA spinal stiffness is not significantly different when measured before and after thrust manipulation, but any potential mechanical effects appear associated with the manipulated spinal level rather than other levels