694 research outputs found
Buried alive: Aquatic plants survive in āghost pondsā under agricultural fields
The widespread loss of wetlands due to agricultural intensification has been highlighted as a major threat to aquatic biodiversity. However, all is not lost as we reveal that the propagules of some aquatic species could survive burial under agricultural fields in the sediments of āghost pondsā - ponds in-filled during agricultural land consolidation. Our experiments showed at least eight aquatic macrophyte species to germinate from seeds and oospores, following 50ā150 years of dormancy in the sediments of ghost ponds. This represents a significant proportion of the expected macrophyte diversity for local farmland ponds, which typically support between 6 and 14 macrophyte species. The rapid (< 6 months) re-colonisation of resurrected ghost ponds by a diverse aquatic vegetation similarly suggests a strong seed-bank influence. Ghost ponds represent abundant, dormant time capsules for aquatic species in agricultural landscapes around the globe, affording opportunities for enhancing landscape-scale aquatic biodiversity and connectivity. While reports of biodiversity loss through agricultural intensification dominate conservation narratives, our study offers a rare positive message, demonstrating that aquatic organisms survive prolonged burial under intensively managed agricultural fields. We urge conservationists and policy makers to consider utilizing and restoring these valuable resources in biodiversity conservation schemes and in agri-environmental approaches and policies
Concurrent Resistance and Aquatic Treadmill Training Elicits Greater Lean Mass Gains than Resistance Training Alone.
PURPOSE: To examine the effects of combined aquatic treadmill training (ATM) and resistance training (RT) on body composition (Bcomp), strength, and VO2max following 12 wks of training compared to RT alone. METHODS: 5 healthy, sedentary men (32.6yr Ā±11, 187.5 cm Ā±4.9, 107.9 kg Ā±19.5) and 6 women (34.2 yrs Ā±14.3, 166.6 cm Ā±8.4, 78.6 kg Ā±19.69) were recruited and screened to assess VO2max (GXT), Bcomp (DEXA), and strength. During strength assessment, 1RMs were assessed in this order: leg press, chest press, leg curl, lat pull, leg ext, triceps push-down, biceps curl. Subjects were then randomized into 2 groups. Both groups (R = resistance training, CT = concurrent training) performed progressive RT for 12 wks (2/wk, 3 x 8-12 @ 60%1RM, ~1.5min rest int.). Following wk 6, 1RMs were reassessed and intensity was increased for wks 7-12 (3 x 4-8, beginning @ 75%1RM). Concurrently, the CT group performed 12 wks of progressive ATM (60ā85%VO2max). VO2max was reassessed following wk 6. ATM occurred immediately following RT sessions and in isolation on a 3rd day during the wk. After training, baseline tests were again performed. A 2x3 factorial ANOVA w/ repeated measures for group (2) by time (3) was used to examine absolute and relative changes in body composition, strength, and VO2max
Remote work across jobs, companies and space
The pandemic catalyzed an enduring shift to remote work. To measure and characterize this shift, we examine more than 250 million job vacancy postings across five English-speaking countries. Our measurements rely on a state-of-the-art language-processing framework that we fit, test, and refine using 30,000 human classifications. We achieve 99% accuracy in flagging job postings that advertise hybrid or fully remote work, greatly outperforming dictionary methods and also outperforming other machine-learning methods. From 2019 to early 2023, the share of postings that say new employees can work remotely one or more days per week rose more than three-fold in the U.S and by a factor of five or more in Australia, Canada, New Zealand and the U.K. These developments are highly non-uniform across and within cities, industries, occupations, and companies. Even when zooming in on employers in the same industry competing for talent in the same occupations, we find large differences in the share of job postings that explicitly offer remote work
Prediction of the Total Energy Cost of an Acute Bout of Resistance Exercise in Young Men and Women
Prediction of the Total Energy Cost of an Acute Bout of Resistance Exercise in Young Men and Women
Brad S. Lambertā , Steven E. Martinā”, John S. Greenā” (FACSM), Aaron F. Carbuhnā , Stephen F. Crouseā” (FACSM). Department of Health and Kinesiology, Texas A&M University, College Station, TX (Sponsor S.F. Crouse)
ACSM currently recommends resistance training (RT) for each major muscle group at least 2 times per week with a traditional repetition range of 8-12 per set. Because many investigators as well as fitness professionals consider kcal expenditure when creating training protocols, energy costs during both RT and aerobic training must be considered. PURPOSE: To develop a regression equation to predict kcal expenditure for a RT bout involving each major muscle group using VO2max, height, weight, lean body mass, fat mass, and total exercise volume (TV=sets*reps*wt) as independent variables. METHODS: Twelve subjects (7 men, 5 women, age 21-25 yrs) were tested using the standard Bruce treadmill protocol for VO2max, and strength tested to determine their 3-5 repetition max (RM) on KeiserĀ® RT equipment 1 week prior to their experimental RT bout. Body composition was assessed using DEXA. For their experimental RT bout, a warm-up set followed by 2-3 sets of 8-12 reps at 60-70% predicted 1RM were performed for each exercise. Each set was started every two minutes. Exercises progressed in the following order: leg press, chest press, leg curl, lat pull, leg ext., triceps ext., biceps curl. Oxygen consumption was measured continuously throughout the RT bout using an automated metabolic cart. Multiple Linear Regression was used to determine the best model for prediction of kcal consumption. Results: Mean kcal expenditure for the entire RT bout was 221.8Ā±20.65 kcal (men = 272Ā±36 & women = 150Ā±16) with a mean kcal cost of 26.32-38.94 per exercise. Large muscle group/multi-joint exercises had the highest total kcal expenditures as expected. Collinearity diagnostics from the regression revealed that VO2max (L/min) and the square root of TV (TV0.5) were the only predictors needed in the model with all other variables being highly intercorrellated with VO2max (L/min), thus not adding significant improvement to the model. The prediction equation was (p\u3c0.05, R2=0.86):
Total kcal = (37.264*VO2max L/min) + (1.087*TV0.5) ā 132.488
CONCLUSIONS: VO2max (L/min) and TV0.5 were found to be significant predictors of the energy cost of a RT bout involving each major muscle group. In regards to fitness, performance, and weight management, this equation may aid practitioners and young exercising adults in documenting kcal expenditure from resistance training
Association of Aerobic Fitness and Metabolic Syndrome in Male Firefighters
Metabolic syndrome has been shown in numerous studies to be related to a higher incidence of coronary artery disease. A study by Jurca and coworkers (Med. Sci. Sports Exerc 36(8):1301-1307, 2004) found a relationship between aerobic fitness and the prevalence of metabolic syndrome in a group of men enrolled in the Aerobics Center Longitudinal Study (ACLS). In addition, recent work in our lab (Int J Exerc Sci 2(1): S43, 2009) has supported these findings. However, research exploring this relationship is still lacking in male firefighters, whose leading cause of line-of-duty deaths is heart attacks. Purpose: To further evaluate the association of metabolic syndrome and aerobic fitness in male fire fighters. Methods: As part of an annual physical exam, 210 male fire fighters (average age = 36) underwent evaluation of risk factors associated with metabolic syndrome as defined by NCEP III. These include the presence of three or more of the following: Waist Circumference \u3e 40 , HDL Cholesterol \u3c 40 mg/dL, Triglycerides \u3e 150 mg/dL, Blood Glucose \u3e 110 mg/dL, and Resting Blood Pressure \u3e 130/85 mm Hg. Aerobic Fitness was determined by estimating VO2max from time on treadmill during a Bruce protocol. Results: The subjects were ranked and divided into quartiles based on VO2max. All data were analyzed using a Chi Square test (p \u3c 0.05). Prevalence of metabolic syndrome increased significantly across quartiles as aerobic fitness declined. Conclusion: These data suggest that as aerobic fitness improves, the likelihood of male firefighters having metabolic syndrome decreases
Relationship between community drug administration strategy and changes in trachoma prevalence, 2007 to 2013
Australia is the only high income country with persisting endemic trachoma and a national control program has been in place since 2006. The program involves annual screening of children for trachoma in communities designated to be at high risk of disease and treatment of those affected with the antibiotic azithromycin. Depending on the level of trachoma detected in children, antibiotic treatment is also given to households and other community members. We used data collected annually from 2007 to 2013 to examine what effect the extent of azithromycin treatment had on subsequent levels of trachoma in children aged 5ā9 years. We found that in communities with high levels of trachoma, when all community members received azithromycin (community-wide treatment), the greatest reduction in trachoma level was achieved. However in communities with moderate levels of trachoma, using either community-wide treatment or more targeted (household) treatment resulted in equivalent reductions in trachoma. This observation needs to be confirmed in other studies before changes to current recommendations regarding trachoma control strategies are considered
The Relationship of Metabolic Syndrome and Aerobic Exercise in Adult Male Fire Fighters
Previous studies have concluded that incidence of Metabolic Syndrome may be greater in male firefighters than in the US male population. A recent study reported that approximately 31% of firefighters were positive for Metabolic Syndrome; compared to 24% for the U.S. male population (NCEPIII). Participation in aerobic exercise may decrease the risk of Metabolic Syndrome as cardiac risk factors are improved. This study aims to determine the effect of aerobic exercise participation on the prevalence of metabolic syndrome in a sample of male firefighters. Purpose: To examine the effect of aerobic exercise participation on the prevalence of Metabolic Syndrome in a sample of adult male firefighters. Methods: As a part of an annual physical exam, 177 male firefighters (average age=36) participated in an evaluation of risk factors associated with Metabolic Syndrome as defined by NCEP III. Metabolic Syndrome is defined as having the presence of three or more of the following: Waist circumference \u3e 40ā, HDL Cholesterol \u3c 40 mg/dl, Triglycerides \u3e 150 mg/dl, Blood Glucose \u3e 110 mg/dl and resting blood pressure \u3e 130/85 mm Hg. Aerobic exercise participation was determined by self reported activity from a standard health history questionnaire. Subjects were classified for aerobic exercise participation as: aerobic exercise participation of less than or equal to 1 day per week (LOW), 2 to 3 days per week (MOD), and aerobic exercise participation greater than or equal to 4 days per week (HIGH). Results: The subjects were divided into groups based on the level of weekly aerobic activity. All data were analyzed using a Chi Square test (p \u3c 0.05). Of the 177 firefighters tested 46.3% (82) reported LOW, 48% (85) reported MOD, and 5.6% (10) reported HIGH weekly aerobic activity. The prevalence of Metabolic Syndrome for LOW was 25.6% (21) while the prevalence of Metabolic Syndrome for MOD was 15.3% (13). No one in the HIGH group met the criteria for Metabolic Syndrome. Conclusion: Participation in aerobic exercise appears to affect the incidence of metabolic syndrome in adult male fire fighters
Aquatic treadmill running reduces muscle soreness following intense sprint exercise in trained men
Delayed onset muscle soreness is associated with muscle damage, disturbances in proprioception, and decreases in muscular power. The purpose was to determine if short duration aquatic treadmill (ATM) running reduces muscle soreness following intense sprint exercise in trained men. Twenty trained men (180.3Ā±4.4cm, 86.3Ā±5.8kg, 20Ā±1yr) were recruited and randomly divided into two groups: ATM recovery (ATMRec) and passive recovery (PRec). During testing, subjects performed a warm-up followed by sixteen 110yrd cutback runs with a sprint of 60yrds, sharp change of direction, and a return sprint of 50yrds. Work to rest ratio was set at 1:3. Additionally, following exercise, the ATMRec group performed ATM running using a HydroWorxĀ® treadmill at 5mph, 50% maximal jet resistance, and water(33Ā°C) level at chest depth for 10min. Both groups then evaluated their level of soreness/pain using a numerical rating scale (NRS: 0-10, 0=no pain, 10=worst pain) immediately following all exercise (IPE), 24h, and 48h post exercise in the following regions: ARMS, LEGS, BACK, CHEST, SHOULDERS, HIPS, ABDOMEN, NECK, OVERALL. Data were analyzed for group x time interactions using a 2x3 Generalized Linear Mixed Model for non-parametric data (Ī±ā¤0.05). For significant interactions, the same procedure was used to analyze between group differences at the same measurement timepoint(Ī±ā¤0.05)
Cross-validation of a Prediction Equation for Energy Expenditure of an Acute Resistance Exercise Bout
Previously, our laboratory introduced a regression equation for predicting net kcal consumption of a resistance exercise (RE) bout: Total net kcal = 0.874(height, cm) - 0.596(age, years) - 1.016(fat mass, kg) + 1.638(lean mass, kg) + 2.461(total volume x 10-3) - 110.742 (R2 = 0.773, SEE=28.5 kcal). PURPOSE: The purpose of this study was to validate this regression equation using the same variables as predictors. METHODS: Forty-seven healthy, active subjects (23 men, 24 women, 20-58 yrs, 173.5 Ā± 10.5 cm, 85.5 Ā± 19.0 kg, VO2max 36.0 Ā± 8.4 ml/kg/min) were randomly divided into validation and cross-validation groups (nv = 24, ncv = 23). The validation groupās data was used to develop an equation to predict net kcal consumption, which was applied to the cross-validation groupās data to estimate net kcal consumption. Similarly, a prediction equation was derived from the cross-validation groupās raw data and applied to that of the validation group. The strength of the relationship between each groupās measured and estimated net kcal consumption was assessed via correlational analysis. RESULTS: Multiple linear regression yielded the following estimates of net kcal consumption: validation net kcal = 1.125(height, cm) ā 0.662(age, years) ā 0.800(fat mass, kg) + 1.344(lean mass, kg) + 2.278(total volume x 10-3) ā 144.846 (R2 = 0.751, p \u3c 0.0001, SEE=29.7 kcal); cross-validation net kcal = 0.515(height, cm) - 0.520(age, years) - 1.220(fat mass, kg) + 1.995(lean mass, kg) + 2.620(total volume x 10-3) ā 59.988 (R2 = 0.823, p \u3c 0.0001, SEE=29.2 kcal). These equations had a cross-validation coefficient of 0.902 and a double cross-validation coefficient of 0.863. CONCLUSION: The strong relationship between the measured and estimated net kcal consumption of both the cross-validation and validation group lead us to conclude that the regression equation derived by this laboratory is valid for estimating net energy expenditure for a total RE bout
The Zwicky Transient Facility Observing System
The Zwicky Transient Facility (ZTF) is a synoptic optical survey for high-cadence time-domain astronomy. Building upon the experience and infrastructure of the highly successful Palomar Transient Factory (PTF) team, ZTF will survey more than an order of magnitude faster than PTF in sky area and volume in order to identify rare, rapidly varying optical sources. These sources will include a trove of supernovae, exotic explosive transients, unusual stellar variables, compact binaries, active galactic nuclei, and asteroids. The single-visit depth of 20.4 mag is well matched to spectroscopic follow-up observations, while the co-added images will provide wide sky coverage 1.5 ā 2 mag deeper than SDSS. The ZTF survey will cover the entire Northern Sky and revisit fields on timescales of a few hours, providing hundreds of visits per field each year, an unprecedented cadence, as required to detect fast transients and variability. This high-cadence survey is enabled by an observing system based on a new camera having 47 deg^2 field of view ā a factor of 6.5 greater than the existing PTF camera - equipped with fast readout electronics, a large, fast exposure shutter, faster telescope and dome drives, and various measures to optimize delivered image quality. Our project has already received an initial procurement of e2v wafer-scale CCDs and we are currently fabricating the camera cryostat. International partners and the NSF committed funds in June 2014 so construction can proceed as planned to commence engineering commissioning in 2016 and begin operations in 2017. Public release will allow broad utilization of these data by the US astronomical community. ZTF will also promote the development of transient and variable science methods in preparation for the seminal first light of LSST
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