Exercise-Induced Glycogen Reduction Increases Muscle Activity

International Journal of Exercise Science 9(3): 336-346, 2016. Intramuscular glycogen stores are an important energy source during extended bouts of strenuous exercise. A substantial reduction in glycogen could influence neural muscular drive and result in a decreasing quality of exercise performance and potentially increased injury rates. The aim of this study was to examine the effect of glycogen reduction on motor drive as determined by the surface electromyogram (EMG) amplitude and median frequency during a cycling graded exercise test. Eight trained cyclists performed a discontinuous cycling graded exercise test to exhaustion under both normal and glycogen reduced conditions. EMG was collected from the vastus lateralis. Repeated measures regression models indicated that EMG amplitudes were elevated at cycling workloads higher than 196 Watts and metabolic workloads higher than 40.8 ml/kg/min, corresponding to 77% VO2max. There was no effect of increases in workload or glycogen reduction on EMG median frequency. Changes in mechanical and metabolic workload had a substantial effect on EMG amplitude (Cohen’s f2 = 0.227 and 0.247, respectively), but not median frequency (Cohen’s f2 = 0.026 and 0.033, respectively). Thus, EMG amplitude is a more effective and reliable measure to examine changes in motor drive during variable workload conditions and metabolic perturbations. The results suggest that healthy glycogen reduced humans require higher levels of muscle activity in order to attain a given mechanical and metabolic workload. This may affect the long term performance of professional and military athletes who need to be able to perform at a high level for extended periods of activity

Risk factors for heart failure in patients with type 2 diabetes mellitus and stage 4 chronic kidney disease treated with bardoxolone methyl

Background: A phase 3 randomized clinical trial was designed to test whether bardoxolone methyl, a nuclear factor erythroid-2–related factor 2 (Nrf2) activator, slows progression to end-stage renal disease in patients with stage 4 chronic kidney disease and type 2 diabetes mellitus. The trial was terminated because of an increase in heart failure in the bardoxolone methyl group; many of the events were clinically associated with fluid retention.<p></p> Methods and Results: We randomized 2,185 patients with type 2 diabetes mellitus (T2DM) and stage 4 chronic kidney disease (CKD) (estimated glomerular filtration rate 15 to <30 mL min−1 1.73 m−2) to once-daily bardoxolone methyl (20 mg) or placebo. We used classification and regression tree analysis to identify baseline factors predictive of heart failure or fluid overload events. Elevated baseline B-type natriuretic peptide and previous hospitalization for heart failure were identified as predictors of heart failure events; bardoxolone methyl increased the risk of heart failure by 60% in patients with these risk factors. For patients without these baseline characteristics, the risk for heart failure events among bardoxolone methyl– and placebo-treated patients was similar (2%). The same risk factors were also identified as predictors of fluid overload and appeared to be related to other serious adverse events.<p></p> Conclusions: Bardoxolone methyl contributed to events related to heart failure and/or fluid overload in a subpopulation of susceptible patients with an increased risk for heart failure at baseline. Careful selection of participants and vigilant monitoring of the study drug will be required in any future trials of bardoxolone methyl to mitigate the risk of heart failure and other serious adverse events.<p></p&gt

Performance of a Magnesium-Rich Primer on Pretreated AA2024-T351 in Full Immersion: a Galvanic Throwing Power Investigation Using a Scanning Vibrating Electrode Technique

The scanning vibrating electrode technique (SVET) was employed to examine the effect of ‘galvanic throwing power’ and the distance over which a Mg-rich primer (MgRP) provided sacrificial anode-based cathodic protection to AA2024-T351. Three systems were investigated in full immersion conditions where the same MgRP was used with three different pretreatments: Non-film forming (NFF), trivalent chromium pretreatment (TCP) and anodization with a chromate seal (ACS). Experiments were conducted with two coating/defect area ratios and three parameters were monitored: 1) the maximum peak height of local anodes, inferring the location and intensity of pits, 2) the current density profile at the coating/defect interface (CDI) region and 3) total integrated anodic and cathodic current density values of defined areas in the defect region moving progressively away from the CDI. The NFF-based system was shown to provide the superior galvanic throwing power and a quasi-steady-state galvanic current distribution was detected in the defect region adjacent to the CDI indicating enhanced cathodic activity in response to the MgRP. High resistance between the MgRP and the substrate, due to the thickness of the pretreatment layer, appeared to mediate galvanic interactions in the case of TCP and ACS-based systems

Multi-Line Gamma-Ray Spectrometer Performance of a Si(Li) Detector Stack

Experimental data is presented which for the first time displays multi-line spectrometer performance of a Si(Li) detector stack at elevated temperature. The stack consists of four elements, each with a 2 cm diameter active area. Ba-133 and Ag-110m spectra are obtained using various techniques to enhance the peak-to-background ratio. Spectral data are shown as a function of temperature (94 K less than or = T less than or = 230 K) using optimized peak shaping

Referral for specialist follow-up and its association with post-discharge mortality among patients with systolic heart failure (from the National Heart Failure Audit for England and Wales)

For patients admitted with worsening heart failure, early follow-up after discharge is recommended. Whether outcomes can be improved when follow-up is done by cardiologists is uncertain. We aimed to determine the association between cardiology follow-up and risk of death for patients with heart failure discharged from hospital. Using data from the National Heart Failure Audit (England & Wales), we investigated the effect of referral to cardiology follow-up on 30-day and one-year mortality in 68 772 patients with heart failure and a reduced left ventricular ejection fraction (HFREF) discharged from 185 hospitals between 2007 to 2013. The primary analyses used instrumental variable analysis complemented by hierarchical logistic and propensity matched models. At the hospital level, rates of referral to cardiologists varied from 6% to 96%. The median odds ratio (OR) for referral to cardiologist was 2.3 (95% confidence interval [CI] 2.1, 2.5), suggesting that, on average, the odds of a patient being referred for cardiologist follow-up after discharge differed approximately 2.3 times from one randomly selected hospital to another one. Based on the proportion of patients (per region) referred for cardiology follow-up, referral for cardiology follow-up was associated with lower 30-day (OR 0.70; CI 0.55, 0.89) and one-year mortality (OR 0.81; CI 0.68, 0.95) compared with no plans for cardiology follow-up (i.e., standard follow-up done by family doctors). Results from hierarchical logistic models and propensity matched models were consistent (30-day mortality OR 0.66; CI 0.61, 0.72 and 0.66; CI 0.58, 0.76 for hierarchical and propensity matched models, respectively). For patients with HFREF admitted to hospital with worsening symptoms, referral to cardiology services for follow-up after discharge is strongly associated with reduced mortality, both early and late

Effects of dalcetrapib in patients with a recent acute coronary syndrome

In observational analyses, higher levels of high-density lipoprotein (HDL) cholesterol have been associated with a lower risk of coronary heart disease events. However, whether raising HDL cholesterol levels therapeutically reduces cardiovascular risk remains uncertain. Inhibition of cholesteryl ester transfer protein (CETP) raises HDL cholesterol levels and might therefore improve cardiovascular outcomes

Transitioning to adulthood with a mild intellectual disability: Young people's experiences, expectations, and aspirations

Aim: Very little attention has been paid to the views and experiences of young people with mild intellectual disabilities on the broad topics of adulthood and adult identity. The following study was undertaken to explore how young adults with mild intellectual disabilities conceptualize, relate to, and experience the process of transition. Method: Eight young adults with mild to borderline intellectual disabilities participated in semi‐structured interviews. Results were analysed using interpretive thematic analysis. Results: Two umbrella themes were identified: “On a developmental pathway” and “Negotiations in the environment”. Conclusions: The participants concerns were surprisingly similar to those commonly expressed by young adults without disabilities. Self‐perceived adult identity appeared to be affected by the participants' personal definitions of adulthood, as well as by social comparisons with both peers and adults. Finally, while concerns were expressed about their capacity to cope with responsibility, most felt optimistic about adopting full adult status in the future

Impact of Renal Impairment on Beta-Blocker Efficacy in Patients With Heart Failure.

BACKGROUND: Moderate and moderately severe renal impairment are common in patients with heart failure and reduced ejection fraction, but whether beta-blockers are effective is unclear, leading to underuse of life-saving therapy. OBJECTIVES: This study sought to investigate patient prognosis and the efficacy of beta-blockers according to renal function using estimated glomerular filtration rate (eGFR). METHODS: Analysis of 16,740 individual patients with left ventricular ejection fraction <50% from 10 double-blind, placebo-controlled trials was performed. The authors report all-cause mortality on an intention-to-treat basis, adjusted for baseline covariates and stratified by heart rhythm. RESULTS: Median eGFR at baseline was 63 (interquartile range: 50 to 77) ml/min/1.73 m2; 4,584 patients (27.4%) had eGFR 45 to 59 ml/min/1.73 m2, and 2,286 (13.7%) 30 to 44 ml/min/1.73 m2. Over a median follow-up of 1.3 years, eGFR was independently associated with mortality, with a 12% higher risk of death for every 10 ml/min/1.73 m2 lower eGFR (95% confidence interval [CI]: 10% to 15%; p < 0.001). In 13,861 patients in sinus rhythm, beta-blockers reduced mortality versus placebo; adjusted hazard ratio (HR): 0.73 for eGFR 45 to 59 ml/min/1.73 m2 (95% CI: 0.62 to 0.86; p < 0.001) and 0.71 for eGFR 30 to 44 ml/min/1.73 m2 (95% CI: 0.58 to 0.87; p = 0.001). The authors observed no deterioration in renal function over time in patients with moderate or moderately severe renal impairment, no difference in adverse events comparing beta-blockers with placebo, and higher mortality in patients with worsening renal function on follow-up. Due to exclusion criteria, there were insufficient patients with severe renal dysfunction (eGFR <30 ml/min/1.73 m2) to draw conclusions. In 2,879 patients with atrial fibrillation, there was no reduction in mortality with beta-blockers at any level of eGFR. CONCLUSIONS: Patients with heart failure, left ventricular ejection fraction <50% and sinus rhythm should receive beta-blocker therapy even with moderate or moderately severe renal dysfunction

Variable Temperature Performance of a Si(Li) Detector Stack

New experimental data is presented which displays 137Cs resolution of both single Si(Li) devices and a detector stack 2 cm in height as a function of temperature (85 K greater than or equal to T greater than or equal to 245 K). We also discuss variations in photopeak shape which indicate that detector charge collection may be temperature dependent over the range of interest

Spatial and Temporal Trends of Freshwater Mussel Assemblages in the Meramec River Basin, Missouri, USA

The Meramec River basin in east-central Missouri has one of the most diverse unionoid mussel faunas in the central United States with .40 species identified. Data were analyzed from historical surveys to test whether diversity and abundance of mussels in the Meramec River basin (Big, Bourbeuse, and Meramec rivers, representing .400 river miles) decreased between 1978 and 1997. We found that over 20 y, species richness and diversity decreased significantly in the Bourbeuse and Meramec rivers but not in the Big River. Most species were found at fewer sites and in lower numbers in 1997 than in 1978. Federally endangered species and Missouri Species of Conservation Concern with the most severe temporal declines were Alasmidonta viridis, Arcidens confragosus, Elliptio crassidens, Epioblasma triquetra, Fusconaia ebena, Lampsilis abrupta, Lampsilis brittsi, and Simpsonaias ambigua. Averaged across all species, mussels were generally being extirpated from historical sampling sites more rapidly than colonization was occurring. An exception was one reach of the Meramec River between river miles 28.4 and 59.5, where mussel abundance and diversity were greater than in other reaches and where colonization of Margaritiferidae, Lampsilini, and Quadrulini exceeded extirpation. The exact reasons mussel diversity and abundance have remained robust in this 30-mile reach is uncertain, but the reach is associated with increased gradients, few long pools, and vertical rock faces, all of which are preferable for mussels. Complete loss of mussel communities at eight sites (16%) with relatively diverse historical assemblages was attributed to physical habitat changes including bank erosion, unstable substrate, and sedimentation. Mussel conservation efforts, including restoring and protecting riparian habitats, limiting the effects of in-stream sand and gravel mining, monitoring and controlling invasive species, and protecting water quality, may be warranted in the Meramec River basin