EFFECTS OF SURFACE ON OXYGEN UPTAKE, POWER OUTPUT, AND HEART RATE DURING UPHILL CYCLING

An alternative to stationary cycling is to use an actual bicycle on a treadmill. While eliminating differences between bicycles, this method may limit inferential conclusions to overground cycling. The current study examined physiological and biomechanical responses while cycling uphill overground versus over treadmill. Thirteen subjects rode uphill at 6.4 km ⋅ hr-1 on a 2.5 X 3.0 m treadmill and an asphalt paved road nine min at 8-12% grade. Power output (PO), cadence (CAD), VO2, and HR, were obtained via telemetry. Mean data from minutes 3 to 6 were analyzed via Two-way (surface by time) Repeated Measures ANOVA. Mean VO2, HR, and PO were higher for treadmill riding than overground (p0.05). No interactions were found. Results of the current study indicate that cycling on a treadmill impose different demands than overground cycling even when the equipment is the same

The Impact of the Cold Pressor Test on Inter-Arm Differences in Blood Pressure

International Journal of Exercise Science 16(2): 875-884, 2023. A large inter-arm difference (IAD+; ≥10mmHg between arms at rest) in blood pressure (BP) at rest is linked to cardiovascular risk, and exercise can change this difference. As mechanisms for IAD are elusive, unique physiological stimuli may provide insight towards a better understanding of this phenomenon. The cold pressor test (CPT) has a potent effect on BP and acts primarily through sympathetic nervous system (SNS) stimulation, though the effects of SNS stimulation on IAD are unknown. Therefore, the purpose of the present study was to examine the effects of the CPT on IAD. BP was monitored simultaneously using two automated, auscultatory monitors (SunTech Tango) and a non-invasive hemodynamic device (Physioflow). Participants completed a CPT test, including a 15-minute rest, three pre-test BP measurements (averaged), and a three-minute water immersion (3°C; measurements at 30-sec and 2-min). Descriptive statistics were calculated, and a repeated measures ANOVA test used to compare both the absolute and relative IAD responses. The CPT induced an average absolute increase in IAD of 4.0 mmHg at 30-sec and 6.7mmHg at 2-min across all participants (P\u3c0.05). Differences in both the absolute and relative IAD responses to the CPT were noted between IAD- and IAD+ individuals (P\u3c0.05). Despite a consistent HR response to the CPT between groups, stroke volume was lower in IAD+ participants at 30-sec and 2-min. Sympathetic stimulation via the CPT induced changes in both the inter-arm difference in blood pressure and hemodynamics in young, apparently-healthy individuals

Eight Weeks of Kettlebell Swing Training Does Not Improve Sprint Performance in Recreationally Active Females

International Journal of Exercise Science 9(4): 437-444, 2016. The kettlebell swing (KBS), emphasizing cyclical, explosive hip extension in the horizontal plane, aligns with movement- and velocity-specificity of sprinting. The present study examined the effect of an eight-week KBS intervention on sprinting in recreationally-active females, in comparison to an eight-week intervention using the stiff-legged deadlift (SDL). Following a pre-testing session measuring 30 meter sprint and countermovement vertical jump performance, participants were divided evenly by sprint time into KBS (n=8) and SDL (n=10) cohorts. Following familiarization with the exercises, KBS met twice weekly to perform swings using the Tabata interval (20s work, 10s rest, 8 rounds), stressing a rapid, explosive tempo. In contrast, the SDL group performed their Tabata stiff-legged deadlifts at a conventional resistance training tempo (2 seconds concentric, 2 seconds eccentric). Following eight weeks and greater than 95% training adherence, the SDL group only had a slightly greater average training volume (~3%) than KBS. No significant differences in pre-test values, or changes were noted in sprint performance from pre- to post-intervention in either group. An improvement in vertical jump performance was noted across groups. Potential explanations for the lack of sprint improvement compared to previous studies include differences between recreationally-active and athletic females, and low exercise volume (~46% of a comparable study with improvements in vertical jump). Future studies should seek to determine the appropriate volume and intensity for KBS components of sprint programming

Comparison of polychlorinated biphenyl levels across studies of human neurodevelopment.

Polychlorinated biphenyls (PCBs) are persistent pollutants that are ubiquitous in the food chain, and detectable amounts are in the blood of almost every person in most populations that have been examined. Extensive evidence from animal studies shows that PCBs are neurotoxins, even at low doses. Interpretation of human data regarding low-level, early-life PCB exposure and subsequent neurodevelopment is problematic because levels of exposure were not similarly quantified across studies. We expressed the exposure levels from 10 studies of PCB and neurodevelopment in a uniform manner using a combination of data from original investigators, laboratory reanalyses, calculations based on published data, and expert opinion. The mainstay of our comparison was the median level of PCB 153 in maternal pregnancy serum. The median concentration of PCB 153 in the 10 studies ranged from 30 to 450 ng/g serum lipid, and the median of the 10 medians was 110 ng/g. We found that (a)) the distribution of PCB 153 exposure in most studies overlapped substantially, (b)) exposure levels in the Faroe Islands study were about 3-4-fold higher than in most other studies, and (c)) the exposure levels in the two recent U.S. studies were about one-third of those in the four earlier U.S. studies or recent Dutch, German, and northern Québec studies. Our results will facilitate a direct comparison of the findings on PCBs and neurodevelopment when they are published for all 10 studies

Images of Eyes Enhance Investments in a Real-Life Public Good

A key issue in cooperation research is to determine the conditions under which individuals invest in a public good. Here, we tested whether cues of being watched increase investments in an anonymous public good situation in real life. We examined whether individuals would invest more by removing experimentally placed garbage (paper and plastic bottles) from bus stop benches in Geneva in the presence of images of eyes compared to controls (images of flowers). We provided separate bins for each of both types of garbage to investigate whether individuals would deposit more items into the appropriate bin in the presence of eyes. The treatment had no effect on the likelihood that individuals present at the bus stop would remove garbage. However, those individuals that engaged in garbage clearing, and were thus likely affected by the treatment, invested more time to do so in the presence of eyes. Images of eyes had a direct effect on behaviour, rather than merely enhancing attention towards a symbolic sign requesting removal of garbage. These findings show that simple images of eyes can trigger reputational effects that significantly enhance on non-monetary investments in anonymous public goods under real life conditions. We discuss our results in the light of previous findings and suggest that human social behaviour may often be shaped by relatively simple and potentially unconscious mechanisms instead of very complex cognitive capacities

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino