The effects of heat stress on neuromuscular activity during endurance exercise

This study analysed the effect of hot (35 C) and cold (15 C) environments on electromyographic (EMG) signal characteristics, skin and rectal temperatures and heart rate during progressive endurance exercise. Eight healthy subjects performed three successive 15-min rides at 30%, 50% and 70% of their peak sustained power output and then cycled at increasing (15 W/min) work rates to exhaustion in both 35 C and 15 C environments. Skin and rectal temperatures, heart rate and EMG data were measured during the trials. The skin temperatures were higher and the subjects felt more uncomfortable in the hot conditions (Bedford scale) (P<0.01). Rectal temperature was slightly, but not significantly, higher under hot conditions. Heart rate was significantly higher in the hot group (between condition P<0.05). Peak power output (267.4€67.7 W vs. 250.1€61.5 W) and time-toexhaustion (55.7€16.7 min vs. 54.5€17.1 min) (COLD vs. HOT) were not different between conditions. There were no differences in integrated EMG (IEMG) or mean power frequency spectrum between conditions. Rating of perceived exertion increased similarly in both conditions over time. Although the hot conditions increased heart rate and skin temperature, there were no differences in muscle recruitment or maximal performance, which suggests that the thermal stress of 35 C, in combination with exercise, did not impair maximal performance in this study

Peak rates of diuresis in healthy humans during oral fluid overload

Objective. To determine whether rates of intestinal fluid absorption and renal diuresis can match high rates of fluid ingestion in healthy humans exposed to oral fluid overload, thereby preventing the development of hyponatraemia either by reverse sodium movement across the intestine (the Priestley-Haldane effect) or by expansion of the extracellular fluid volume.Methods. Changes in renal function and in plasma chemical measurements in response to an oral fluid overload (0.9 - 1.8 1/ h x 3 h) were investigated in 6 healthy control subjects at rest, and in a subject with a history of exercise induced symptomatic hyponatraemia, during both prolonged (160-minute) exercise and at rest.Findings. All control subjects gained weight (2.7 ± 0.2 kg, mean ± standard error of mean (SEM)) because the rate of oral fluid intake exceeded the peak rate of urine production (778 ± 39 rnl / h). Blood volume rose by 7.1 (± 0.5)% and plasma sodium concentrations fell progressively from 144 ± 2.6 to 136 ± 1.1 mmol/ 1 (P < 0.05) in the control subjects. Plasma potassium and angiotensin II concentrations were unchanged and creatinine clearance was normal ( -125 rnl/min). Free water clearance reached a maximum of 11.2 ± 0.9 rnl/min after 2 hours. The increase in body mass could be accounted for by calculated or measured changes in extra- and intracellular fluid volumes. Similar changes were measured in the subject with a previous history of symptomatic hyponatraernia.Conclusion. The rate of intestinal fluid absorption appeared to match the rate of oral fluid ingestion and there was no  evidence of fluid accumulation in the intestine with reverse sodium movement from the extracellular space into intestinal fluid. The results of this study are therefore at variance with the Priestley-Haldane hypothesis and suggest that reverse sodium movement did not contribute to the hyponatraernia induced by oral fluid overload in these subjects. Rather it appears that humans may have a limited capacity to excrete fluid at rates in excess of -900 rnl/ h in response to higher rates of oral fluid intake. When the rate of intestinal fluid absorption matches the rate of fluid ingestion and exceeds the kidneys' maximum capacity for fluid excretion, the excess fluid accumulates in the extra- and intracellular fluid compartments, inducing the dilutional hyponatraemia of water intoxication. These findings may have relevance to other clinical conditions in which hyponatraemia develops in response to high rates of oral or intravenous fluid provision

Caffeine ingestion does not alter performance during a 100-km cycling time-trial performance

This study analyzed the effect of caffeine ingestion on performance during a repeated-measures, 100-km, laboratory cycling time trial that included bouts of 1- and 4-km high intensity epochs (HIE). Eight highly trained cyclists participated in 3 separate trials - placebo ingestion before exercise with a placebo carbohydrate solution and placebo tablets during exercise (Pl), or placebo ingestion before exercise with a 7% carbohydrate drink and placebo tablets during exercise (Cho), or caffeine tablet ingestion before and during exercise with 7% carbohydrate (Caf). Placebo (twice) or 6 mg · kg-1 caffeine was ingested 60 min prior to starting 1 of the 3 cycling trials, during which subjects ingested either additional placebos or a caffeine maintenance dose of 0.33 mg · kg-1 every 15 min to trial completion. The 100-km time trial consisted of five 1-km HIE after 10, 32, 52, 72, and 99 km, as well as four 4-km HIE after 20, 40, 60, and 80 km. Subjects were instructed to complete the time trial and all HIE as fast as possible. Plasma (caffeine) was significantly higher during Caf (0.43 ± 0.56 and 1.11 ± 1.78 mM pre vs. post Pl; and 47.32 ± 12.01 and 72.43 ± 29.08 mM pre vs. post Caf). Average power, HIE time to completion, and 100-km time to completion were not different between trials. Mean heart rates during both the 1-km HIE (184.0 ± 9.8 Caf; 177.0 ± 5.8 Pl; 177.4 ± 8.9 Cho) and 4-km HIE (181.7 ± 5.7 Caf; 174.3 ± 7.2 Pl; 175.6 ± 7.6 Cho;p less than .05) was higher in Caf than in the other groups. No significant differences were found between groups for either EMG amplitude (IEMG) or mean power frequency spectrum (MPFS). IEMG activity and performance were not different between groups but were both higher in the 1-km HIE, indicating the absence of peripheral fatigue and the presence of a centrally-regulated pacing strategy that is not altered by caffeine ingestion. Caffeine may be without ergogenic benefit during endurance exercise in which the athlete begins exercise with a defined, predetermined goal measured as speed or distance

Measurement of fisheries compliance outcomes : a preliminary national study : FRDC final report

This report presents the results of a project undertaken by a group of Australia and United States based fishery compliance experts to assess and compare methods for measuring fisheries compliance outcomes that can be used to assess and compare the effectiveness of fishery enforcement and compliance assistance activities. This eight month project was requested in 2013 by Australia’s National Fisheries Compliance Committee (NFCC) as a way to provide fisheries compliance groups with improved methods for measuring and tracking the effectiveness of their activities and for justifying and managing their budgets

The effect of selective beta1-blockade on EMG signal characteristics during progressive endurance exercise

This study analysed the effect of selective b1- blockade on neuromuscular recruitment characteristics during progressive endurance exercise. Ten healthy subjects ingested a selective b1-blocker, acebutolol (200 mg b.d.), for 7 days (for one of two cycling trials), with a 10-day wash-out period between trials. On the last day of acebutolol ingestion subjects performed three successive 15-min rides at 30%, 50% and 70% of their peak power output and then cycled at increasing (15 W min-1) work rates to exhaustion. Force output, heart rate, submaximal V_O2, rate of perceived exertion (RPE), electromyographic (EMG) data and blood lactate were captured during the cycling activity. Peak work rate [270 (111) W vs 197 (75) W, CON vs BETA, P<0.01], time to exhaustion [49.7 (23.2) min vs 40.3 (23.7) min, CON vs BETA, P <0.05] and heart rate [mean, for the full ride 135.5 (38.3) beats min-1 vs 111.5 (30.0) beats min-1 CON vs BETA, P <0.05] were significantly lower for the group who ingested b1-blockade (BETA) compared to the control group (CON). Although not significant, submaximal V_O2 was reduced in BETA during the ride, while RPE was significantly higher during the ride for BETA (P <0.01). Mean integrated electromyography was higher in the BETA group although these differences were not significant. Mean power frequency values of the BETA group showed a significant (P <0.05) shift to the upper end of the spectrum in comparison to the control group. Lactate values [11.7 (3.5) mmol.l-1 vs 7.1 (4.1) mmol.l-1 CON vs BETA] were significantly lower (P <0.05) at exhaustion in BETA. Significant reductions in cycling performance were found when subjects ingested b1- blockers. This study has shown significant shifts to the upper end of the EMG frequency spectrum after b1- blocker ingestion, which could be caused by a change in neuromuscular recruitment strategy to compensate for the impaired submaximal exercise performance

Chronic disease risk factors, healthy days and medical claims in South African employees presenting for health risk screening

BACKGROUND: Non-communicable diseases (NCD) accounts for more than a third (37%) of all deaths in South Africa. However, this burden of disease can be reduced by addressing risk factors. The aim of this study was to determine the health and risk profile of South African employees presenting for health risk assessments and to measure their readiness to change and improve lifestyle behaviour. METHODS: Employees (n = 1954) from 18 companies were invited to take part in a wellness day, which included a health-risk assessment. Self-reported health behaviour and health status was recorded. Clinical measures included cholesterol finger-prick test, blood pressure and Body Mass Index (BMI). Health-related age was calculated using an algorithm incorporating the relative risk for all case mortality associated with smoking, physical activity, fruit and vegetable intake, BMI and cholesterol. Medical claims data were obtained from the health insurer. RESULTS: The mean percentage of participation was 26% (n = 1954) and ranged from 4% in transport to 81% in the consulting sector. Health-related age (38.5 +/- 12.9 years) was significantly higher than chronological age (34.9 +/- 10.3 yrs) (p < 0.001). Both chronological and risk-related age were significantly different between the sectors (P < 0.001), with the manufacturing sector being the oldest and finance having the youngest employees. Health-related age was significantly associated with number of days adversely affected by mental and physical health, days away from work and total annual medical costs (p < 0.001). Employees had higher rates of overweight, smoking among men, and physical inactivity (total sample) when compared the general SA population. Increased health-related expenditure was associated with increased number of risk factors, absenteeism and reduced physical activity. CONCLUSION: SA employees' health and lifestyle habits are placing them at increased risk for NCD's, suggesting that they may develop NCD's earlier than expected. Inter-sectoral differences for health-related age might provide insight into those companies which have the greatest need for interventions, and may also assist in predicting future medical expenditure. This study underscores the importance of determining the health and risk status of employees which could assist in identifying the appropriate interventions to reduce the risk of NCD's among employees

Identifying Regional Priority Areas for Focusing Conservation Actions in Streams and Grasslands: Conservation Planning

In the United States, many resources devoted to conservation are routed through states, but animal and plant populations do not conform to state boundaries. Consequently, neighboring states can enhance their collective conservation impact by coordinating natural resources management. In order to support managers as they review and revise state Wildlife Action Plans in Illinois, Indiana, Michigan, and Wisconsin, this project identified regional conservation priorities for streams and grasslands of the Upper Midwest. Specifically, we (1) selected stream and grassland species of common conservation interest to partnering states, (2) modeled and mapped regional distributions of these species, and (3) used predicted species occurrences to identify regional conservation focal areas.We focused on 31 native grassland and stream species: eight birds, 10 freshwater mussels, 12 fish, and one salamander. The birds, mussels, salamander, and one fish were listed as Species of Greatest Conservation Need (SGCNs) by at least two participating states (Table 1). The remaining 11 fish were reproductive hosts for the selected freshwater mussels. With the help of state Departments of Natural Resources, Natural Heritage programs, and other project partners (Table 3 and Acknowledgments), we compiled comprehensive occurrence data for all 31 species. We also downloaded environmental data for streams and grasslands across the Upper Midwest.We used the assembled species and environmental data to develop regional distribution models for all selected aquatic species and five of the selected grassland birds. The most reliable models were obtained from species with widespread survey data (e.g., fish, birds), although some rare species remained data-limited. It was more difficult to model species with presence-only observations (i.e., no absences recorded; e.g., Mudpuppy) or with surveys whose design or data availability differed among states (e.g., mussels). Predicted species distributions were used to identify regional focal areas for stream and grassland conservation. We used Marxan, a spatially explicit conservation planning software, to design reserve systems that most efficiently protect 10% of the regional populations of all selected SGCNs, which were mostly grassland birds and freshwater mussels. Marxan solutions that addressed these regional conservation priorities emphasized the importance of grassland protection in Illinois and Wisconsin and streams protection in Illinois, Indiana, and Michigan. Proposed focal areas often overlapped with Illinois and Wisconsin Conservation Opportunity Areas, Illinois State Acres For wildlife Enhancement (SAFE) Areas, and Chicago Wilderness’s Green Infrastructure Vision, but this project also points out new areas where conservation initiatives are likely to be effective. Relative to prior efforts, this project’s proposed grassland and stream reserve designs expand coverage to all of Illinois, Indiana, Michigan, and Wisconsin. 3The regional conservation priority maps for streams and grasslands can be used by natural resource managers to ensure that individual state conservation strategies contribute meaningfully to regional goals. State managers can also take a species-specific approach, identifying likely population hotspots within their state by referring to the included high-resolution maps of predicted species distributions. Conservation focal areas spanning state borders highlight opportunities where neighboring states might cooperate to more effectively manage shared natural resources. In summary, by modeling the spatial distributions of selected stream and grassland species, this project provides a regional perspective for conservation in the Upper MidwestIllinois Department of Natural Resources Office of Resource Conservation State Wildlife Grant Program T-94-R-1unpublishednot peer reviewedOpe

Similarity Regression predicts evolution of transcription factor sequence specificity

Transcription factor (TF) binding specificities (motifs) are essential to the analysis of noncoding DNA and gene regulation. Accurate prediction of the sequence specificities of TFs is critical, because the hundreds of sequenced eukaryotic genomes encompass hundreds of thousands of TFs, and assaying each is currently infeasible. There is ongoing controversy regarding the efficacy of motif prediction methods, as well as the degree of motif diversification among related species. Here, we describe Similarity Regression (SR), a significantly improved method for predicting motifs. We have updated and expanded the Cis-BP database using SR, and validate its predictive capacity with new data from diverse eukaryotic TFs. SR inherently quantifies TF motif evolution, and we show that previous claims of near-complete conservation of motifs between human and Drosophila are grossly inflated, with nearly half the motifs in each species absent from the other. We conclude that diversification in DNA binding motifs is pervasive, and present a new tool and updated resource to study TF diversity and gene regulation across eukaryotes

Inhibition of APE1/Ref-1 for Neovascular Eye Diseases: From Biology to Therapy

Proliferative diabetic retinopathy (PDR), neovascular age-related macular degeneration (nvAMD), retinopathy of prematurity (ROP) and other eye diseases are characterized by retinal and/or choroidal neovascularization, ultimately causing vision loss in millions of people worldwide. nvAMD and PDR are associated with aging and the number of those affected is expected to increase as the global median age and life expectancy continue to rise. With this increase in prevalence, the development of novel, orally bioavailable therapies for neovascular eye diseases that target multiple pathways is critical, since current anti-vascular endothelial growth factor (VEGF) treatments, delivered by intravitreal injection, are accompanied with tachyphylaxis, a high treatment burden and risk of complications. One potential target is apurinic/apyrimidinic endonuclease 1/reduction-oxidation factor 1 (APE1/Ref-1). The multifunctional protein APE1/Ref-1 may be targeted via inhibitors of its redox-regulating transcription factor activation activity to modulate angiogenesis, inflammation, oxidative stress response and cell cycle in neovascular eye disease; these inhibitors also have neuroprotective effects in other tissues. An APE1/Ref-1 small molecule inhibitor is already in clinical trials for cancer, PDR and diabetic macular edema. Efforts to develop further inhibitors are underway. APE1/Ref-1 is a novel candidate for therapeutically targeting neovascular eye diseases and alleviating the burden associated with anti-VEGF intravitreal injections

Metal oxide coating of carbon supports for supercapacitor applications.

The global market for wireless sensor networks in 2010 will be valued close to $10 B, or 200 M units. TPL, Inc. is a small Albuquerque based business that has positioned itself to be a leader in providing uninterruptible power supplies in this growing market with projected revenues expected to exceed$26 M in 5 years. This project focused on improving TPL, Inc.'s patent-pending EnerPak{trademark} device which converts small amounts of energy from the environment (e.g., vibrations, light or temperature differences) into electrical energy that can be used to charge small energy storage devices. A critical component of the EnerPak{trademark} is the supercapacitor that handles high power delivery for wireless communications; however, optimization and miniaturization of this critical component is required. This proposal aimed to produce prototype microsupercapacitors through the integration of novel materials and fabrication processes developed at New Mexico Technology Research Collaborative (NMTRC) member institutions. In particular, we focused on developing novel ruthenium oxide nanomaterials and placed them into carbon supports to significantly increase the energy density of the supercapacitor. These improvements were expected to reduce maintenance costs and expand the utility of the TPL, Inc.'s device, enabling New Mexico to become the leader in the growing global wireless power supply market. By dominating this niche, new customers were expected to be attracted to TPL, Inc. yielding new technical opportunities and increased job opportunities for New Mexico