1,364 research outputs found

    Diary of Ten Years Eventful Life of an Early Settler in Western Australia

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    https://commons.und.edu/settler-literature/1095/thumbnail.jp

    Cumulative lifetime stress exposure, depression, anxiety, and well-being in elite athletes: A mixed-method study

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    Research suggests that elite athletes are at increased risk of poor mental health, partly due to the intense demands associated with top-level sport. Despite growing interest in the topic, the factors that influence the mental health and well-being of elite athletes remain unclear. From a theoretical perspective, the accumulation of stress and adversity experienced over the life course may be an important factor. To investigate this possibility, we employed a mixed-method design to: (a) examine whether cumulative lifetime stress predicted depression, anxiety, and well-being in elite athletes; and (b) help explain why cumulative lifetime stress exposure might have resulted in poor mental health and well-being. Ninety-five elite athletes (Mage = 29.81, SD = 10.88) completed the Stress and Adversity Inventory, Patient Health Questionnaire, Generalized Anxiety Disorder 7-item scale, and the Scales of General Well-Being. Hierarchical regression analyses revealed that total count and severity of lifetime stressor exposure significantly predicted greater depression (ÎČ = .42, p < .001; ÎČ = .46, p < .001) and anxiety symptoms (ÎČ = .34, p = .003; ÎČ = .28, p = .018), and worse well-being (ÎČ = -.42, p < .001; ÎČ = -.30, p = .015). Semi-structured interviews were then conducted with six athletes. Thematic analysis revealed that cumulative lifetime stress exposure fostered poor mental health and well-being by promoting maladaptive long-term coping strategies, increasing susceptibility to future stress, and limiting interpersonal relationships. These findings can help practitioners identify, and intervene accordingly with, elite athletes at risk of experiencing stress-related mental health problems

    Assessing lifetime stressor exposure in sport performers:Associations with trait stress appraisals, health, well-being, and performance

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    Research has found that greater lifetime stressor exposure increases the risk for mental and physical health problems. Despite this, few studies have examined how stressors occurring over the entire lifespan affect sport performers’ health, well-being, and performance, partly due to the difficulty of assessing lifetime stressor exposure. To address this issue, we developed a sport-specific stress assessment module (Sport SAM) for the Stress and Adversity Inventory (STRAIN) and then analyzed the instrument’s usability, acceptability, validity, and test-retest reliability. Furthermore, we examined whether trait-like tendencies to appraise stressful situations as a challenge or threat mediated the association between lifetime stressor exposure and health, well-being, and performance. Participants were 395 sport performers (M(age) = 22.50 years, SD = 5.33) who completed an online survey. Results revealed that the Sport SAM demonstrated good usability and acceptability, good concurrent validity in relation to the Adult STRAIN (rs = 0.23 to 0.29), and very good test-retest reliability (r(icc) = 0.87 to 0.89). Furthermore, the Sport SAM was significantly associated with symptoms of depression (ÎČ = 0.21 to 0.24, ps ≀ .001) and anxiety (ÎČ = 0.13 to 0.19, ps ≀ .012), and general physical (ÎČ = 0.24 to 0.27, ps = ≀ 0.001) and mental (ÎČ = 0.23 to 0.32, p ≀ .001) health complaints. Finally, we found that associations between total lifetime non-sport and sport-specific stressor severity and health were mediated by trait stress appraisals. Consequently, these findings may help practitioners better identify sport performers who are at risk of developing stress-related health problems

    Lifetime Stressor Exposure and Psychophysiological Reactivity and Habituation to Repeated Acute Social Stressors

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    This study addressed whether lifetime stressor exposure was associated with psychophysiological reactivity and habituation to a novel laboratory-based stressor. Eighty-six participants (Mage = 23.31 years, SD = 4.94) reported their exposure to lifetime non-sport and sport-specific stressors before completing two consecutive trials of the Trier Social Stress Test while cardiovascular (i.e., heart rate) and endocrine (i.e., salivary cortisol) data were recorded. Exposure to a moderate number of lifetime non-sport and sport-specific stressors was associated with adaptive cardiovascular reactivity, whereas very low or very high stressor exposure was related to maladaptive reactivity. Moreover, experiencing a very low number of lifetime non-sport (but not sport-specific) stressors was associated with poorer habituation. In contrast, lifetime stressor severity was unrelated to cardiovascular reactivity. Finally, greater lifetime non-sport and sport-specific stressor count were associated with blunted cortisol reactivity and poorer habituation. These results suggest that lifetime stressor exposure may influence sport performers’ acute stress responses

    Graphical analysis of interactions between oxidation-reduction sites in two site oxidation-reduction protein

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    Many enzymes that catalyze electron-transfer reaction contain multiple oxidation-reduction centers (sites). The oxidation-reduction potential of one site as well as the kinetics of electron transfer through this site may be altered by the state of reduction of a neighboring site. Oxidation-reduction site interactions may be mechanistically important and quantitation of site interactions would aid the interpretation of thermodynamic data and possibly kinetic data. A graphical means to detect and quantitate interactions between oxidation-reduction sites from oxidation-reduction equilibrium data (type A + B C + D)is described and has its roots in the Scatchard analysis of ligand binding equilibria (type A + B C). Oxidation-reduction sites often have distinct physical properties allowing the titration behavior of specific sites to be monitored. Equilibrium measurements on specific sites of a two site protein allow a further analysis of the data which can be combined with the oxidation-reduction Scatchard analysis to solve for all four specific site equilibrium constants. Ligand binding systems can usually measure only total site binding and simplifying assumptions of identical sites or noninteracting sites are required to solve for the site specific equilibrium constants. Thus, specific site equilibrium measurements offer a distinct advantage over total site measurements. The principles of the method are illustrated by applying the graphical analysis to the two site protein, thioredoxin reductase, which contains an oxidation-reduction active site disulfide in addition to FAD. The specific site oxidation-reduction midpoint potentials (Em) of the FAD and disulfide couples of thioredoxin reductase at pH 6.0, 12[deg]C, were found to be FAD/FADH2-enzyme-(S)2 = -0.183 V, FAD/FADH2-enzyme-(SH)2 = -0.199 V, (FAD)-enzyme-(S)2/(SH)2 = -0.202 V, and (FADH2)-enzyme-(S)2/(SH)2 = -0.218 V. Hence, at pH 6.0, the FAD and disulfide sites of thioredoxin reductase have Em values that differ by approximately 0.019 V and have a negative interaction of about 0.016 V.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24992/1/0000419.pd

    Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress

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    In human addicts, drug relapse and craving are often provoked by stress. Since 1995, this clinical scenario has been studied using a rat model of stress-induced reinstatement of drug seeking. Here, we first discuss the generality of stress-induced reinstatement to different drugs of abuse, different stressors, and different behavioral procedures. We also discuss neuropharmacological mechanisms, and brain areas and circuits controlling stress-induced reinstatement of drug seeking. We conclude by discussing results from translational human laboratory studies and clinical trials that were inspired by results from rat studies on stress-induced reinstatement. Our main conclusions are (1) The phenomenon of stress-induced reinstatement, first shown with an intermittent footshock stressor in rats trained to self-administer heroin, generalizes to other abused drugs, including cocaine, methamphetamine, nicotine, and alcohol, and is also observed in the conditioned place preference model in rats and mice. This phenomenon, however, is stressor specific and not all stressors induce reinstatement of drug seeking. (2) Neuropharmacological studies indicate the involvement of corticotropin-releasing factor (CRF), noradrenaline, dopamine, glutamate, kappa/dynorphin, and several other peptide and neurotransmitter systems in stress-induced reinstatement. Neuropharmacology and circuitry studies indicate the involvement of CRF and noradrenaline transmission in bed nucleus of stria terminalis and central amygdala, and dopamine, CRF, kappa/dynorphin, and glutamate transmission in other components of the mesocorticolimbic dopamine system (ventral tegmental area, medial prefrontal cortex, orbitofrontal cortex, and nucleus accumbens). (3) Translational human laboratory studies and a recent clinical trial study show the efficacy of alpha-2 adrenoceptor agonists in decreasing stress-induced drug craving and stress-induced initial heroin lapse

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

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    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentre−of−massframeisusedtosuppressthelargemulti−jetbackground.Thecross−sectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  Όb-1 of data as a function of transverse momentum (pT) and the transverse energy (ÎŁETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∌0) correlation that grows rapidly with increasing ÎŁETPb. A long-range “away-side” (Δϕ∌π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ÎŁETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ÎŁETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁥2Δϕ modulation for all ÎŁETPb ranges and particle pT
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