Squirrelpox virus: assessing prevalence, transmission and environmental degradation

Red squirrels (Sciurus vulgaris) declined in Great Britain and Ireland during the last century, due to habitat loss and the introduction of grey squirrels (Sciurus carolinensis), which competitively exclude the red squirrel and act as a reservoir for squirrelpox virus (SQPV). The disease is generally fatal to red squirrels and their ecological replacement by grey squirrels is up to 25 times faster where the virus is present. We aimed to determine: (1) the seropositivity and prevalence of SQPV DNA in the invasive and native species at a regional scale; (2) possible SQPV transmission routes; and, (3) virus degradation rates under differing environmental conditions. Grey (n = 208) and red (n = 40) squirrel blood and tissues were sampled. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qPCR) techniques established seropositivity and viral DNA presence, respectively. Overall 8% of squirrels sampled (both species combined) had evidence of SQPV DNA in their tissues and 22% were in possession of antibodies. SQPV prevalence in sampled red squirrels was 2.5%. Viral loads were typically low in grey squirrels by comparison to red squirrels. There was a trend for a greater number of positive samples in spring and summer than in winter. Possible transmission routes were identified through the presence of viral DNA in faeces (red squirrels only), urine and ectoparasites (both species). Virus degradation analyses suggested that, after 30 days of exposure to six combinations of environments, there were more intact virus particles in scabs kept in warm (25°C) and dry conditions than in cooler (5 and 15°C) or wet conditions. We conclude that SQPV is present at low prevalence in invasive grey squirrel populations with a lower prevalence in native red squirrels. Virus transmission could occur through urine especially during warm dry summer conditions but, more notably, via ectoparasites, which are shared by both species

PRIME-HF: Novel Exercise for Older Patients with Heart Failure. A Pilot Randomized Controlled Study

OBJECTIVES: To test the hypothesis that (1) older patients with heart failure (HF) can tolerate COMBined moderate-intensity aerobic and resistance training (COMBO), and (2) 4 weeks of Peripheral Remodeling through Intermittent Muscular Exercise (PRIME) before 4 weeks of COMBO will improve aerobic capacity and muscle strength to a greater extent than 8 weeks of COMBO. DESIGN: Prospective randomized parallel open-label blinded end point. SETTING: Single-site Australian metropolitan hospital. PARTICIPANTS: Nineteen adults (72.8 ± 8.4 years of age) with heart failure with reduced ejection fraction (HFrEF). INTERVENTION: Participants were randomized to 4 weeks of PRIME or COMBO (phase 1). All participants subsequently completed 4 weeks of COMBO (phase 2). Sessions were twice a week for 60 minutes. PRIME is a low-mass, high-repetition regime (40% one-repetition maximum [1RM], eight strength exercises, 5 minutes each). COMBO training involved combined aerobic (40%-60% of peak aerobic capacity [VO2peak ], up to 20 minutes) and resistance training (50-70% 1RM, eight exercises, two sets of 10 repetitions). MEASUREMENTS: We measured VO2peak , VO2 at anaerobic threshold (AT), and muscle voluntary contraction (MVC). RESULTS: The PRIME group significantly increased VO2peak after 8 weeks (2.4 mL/kg/min; 95% confidence interval [CI] = .7-4.1; P = .004), whereas the COMBO group showed minimal change (.2; 95% CI -1.5 to 1.8). This produced a large between-group effect size of 1.0. VO2 at AT increased in the PRIME group (1.6 mL/kg/min; 95% CI .0-3.2) but not in the COMBO group (-1.2; 95% CI -2.9 to .4), producing a large between-group effect size. Total MVC increased significantly in both groups in comparison with baseline; however, the change was larger in the COMBO group (effect size = .6). CONCLUSION: Traditional exercise approaches (COMBO) and PRIME improved strength. Only PRIME training produced statistically and clinically significant improvements to aerobic capacity. Taken together, these findings support the hypothesis that PRIME may have potential advantages for older patients with HFrEF and could be a possible alternative exercise modality

Evidence for variation in the effective population size of animal mitochondrial DNA

Background: It has recently been shown that levels of diversity in mitochondrial DNA are remarkably constant across animals of diverse census population sizes and ecologies, which has led to the suggestion that the effective population of mitochondrial DNA may be relatively constant. Results: Here we present several lines of evidence that suggest, to the contrary, that the effective population size of mtDNA does vary, and that the variation can be substantial. First, we show that levels of mitochondrial and nuclear diversity are correlated within all groups of animals we surveyed. Second, we show that the effectiveness of selection on non-synonymous mutations, as measured by the ratio of the numbers of non-synonymous and synonymous polymorphisms, is negatively correlated to levels of mitochondrial diversity. Finally, we estimate the effective population size of mitochondrial DNA in selected mammalian groups and show that it varies by at least an order of magnitude. Conclusions: We conclude that there is variation in the effective population size of mitochondria. Furthermore we suggest that the relative constancy of DNA diversity may be due to a negative correlation between the effective population size and the mutation rate per generation

Inorganic nitrate as a treatment for acute heart failure: a protocol for a single center, randomized, double-blind, placebo-controlled pilot and feasibility study

Abstract Background Acute heart failure (AHF) is a frequent reason for hospitalization worldwide and effective treatment options are limited. It is known that AHF is a condition characterized by impaired vasorelaxation, together with reduced nitric oxide (NO) bioavailability, an endogenous vasodilatory compound. Supplementation of inorganic sodium nitrate (NaNO3) is an indirect dietary source of NO, through bioconversion. It is proposed that oral sodium nitrate will favorably affect levels of circulating NO precursors (nitrate and nitrite) in AHF patients, resulting in reduced systemic vascular resistance, without significant hypotension. Methods and outcomes We propose a single center, randomized, double-blind, placebo-controlled pilot trial, evaluating the feasibility of sodium nitrate as a treatment for AHF. The primary hypothesis that sodium nitrate treatment will result in increased systemic levels of nitric oxide pre-cursors (nitrate and nitrite) in plasma, in parallel with improved vasorelaxation, as assessed by non-invasively derived systemic vascular resistance index. Additional surrogate measures relevant to the known pathophysiology of AHF will be obtained in order to assess clinical effect on dyspnea and renal function. Discussion The results of this study will provide evidence of the feasibility of this novel approach and will be of interest to the heart failure community. This trial may inform a larger study

Cumulative Risk Effects in the Bullying of Children and Young People with Autism Spectrum Conditions

Students with autism are more likely to be bullied than their typically developing peers. However, several studies have shown that their likelihood of being bullied increases in the context of exposure to certain risk factors (e.g. behaviour difficulties, poor peer relationships). This study explores vulnerability to bullying from a cumulative risk perspective, where the number of risks rather than their nature is considered. 722 teachers and 119 parents of young people with ASC participated in the study. Established risk factors were summed to form a cumulative risk score in teacher and parent models. There was evidence of a cumulative risk effect in both models, suggesting that as the number of risks increased, so did exposure to bullying. A quadratic effect was found in the teacher model, indicating that there was a disproportionate increase in the likelihood of being bullied in relation to the number of risk factors to which a young person was exposed. In light of these findings, it is proposed that more attention needs to be given to the number of risks to which children and young people with ASC are exposed when planning interventions and providing a suitable educational environment