1,952 research outputs found
Volcano dome dynamics at Mount St. Helens:Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets
The surface deformation field measured at volcanic domes provides insights into the effects of magmatic processes, gravity-and gas-driven processes, and the development and distribution of internal dome structures. Here we study short-term dome deformation associated with earthquakes at Mount St. Helens, recorded by a permanent optical camera and seismic monitoring network. We use Digital Image Correlation (DIC) to compute the displacement field between successive images and compare the results to the occurrence and characteristics of seismic events during a 6 week period of dome growth in 2006. The results reveal that dome growth at Mount St. Helens was repeatedly interrupted by short-term meter-scale downward displacements at the dome surface, which were associated in time with low-frequency, large-magnitude seismic events followed by a tremor-like signal. The tremor was only recorded by the seismic stations closest to the dome. We find a correlation between the magnitudes of the camera-derived displacements and the spectral amplitudes of the associated tremor. We use the DIC results from two cameras and a high-resolution topographic model to derive full 3-D displacement maps, which reveals internal dome structures and the effect of the seismic activity on daily surface velocities. We postulate that the tremor is recording the gravity-driven response of the upper dome due to mechanical collapse or depressurization and fault-controlled slumping. Our results highlight the different scales and structural expressions during growth and disintegration of lava domes and the relationships between seismic and deformation signals
Spatial deorientation of upper-Stark-state-selected supersonic beams of CH3F, CH3Cl, CH3Br, and CH3I
Competing in hot conditions at the Tokyo Olympic Games : Preparation strategies used by Australian race walkers
Introduction: The Tokyo 2021 Olympic Games was anticipated to expose athletes to the most challenging climatic conditions experienced in the history of the modern Olympic Games. This study documents strategies executed by Australian endurance athletes during the team holding camp and Olympic Games experiences, including (1) baseline physiological data, training data, and heat acclimation/acclimatization practices; (2) pre- and in-race cooling and nutritional strategies, and (3) Olympic Games race performance data.
Methods: Six athletes (three males, three females; age 24 ± 4 years; VO2max 63.2 ± 8.7 mLâ
kgâ1â
minâ1; sum of 7 skinfolds 53.1 ± 23.4 mm) were observed prior to and during the team holding camp held in Cairns, QLD, Australia. Athletes completed 6â7 weeks of intermittent heat acclimation training, utilizing a combination of 2â4 passive and active acclimation sessions per week. Active acclimation was systematically increased via exposure time, exercise intensity, temperature, and humidity. In the team holding camp, athletes undertook a further 23 heat acclimatization training sessions over 18 days in a continuous fashion. Hyperhydration (using sodium and glycerol osmolytes), and internal and external pre-and in-race cooling methods were also utilized. A low energy availability intervention was implemented with two athletes, as a strategy to periodize ideal race body composition. Race performance data and environmental conditions from the 2021 Olympic Games were also documented.
Results: The highest values for aerobic capacity were 63.6 mLâ
kgâ1â
minâ1 for female race walkers and 73.7 mLâ
kgâ1â
minâ1 for males. Training volume for the six athletes was the highest in the second week of the team holding camp, and training intensity was lowest in the first week of the team holding camp. Performance outcomes included 6th place in the womenâs 20 km event (1:30:39), which was within 2% of her 20 km personal best time, and 8th place in the menâs 50 km event (3:52:01), which was a personal best performance time.
Conclusion: Periodized training, heat acclimation/acclimatization, cooling and nutritional strategies study may have contributed to the race outcomes in Olympic Games held hot, humid conditions, for the race walkers within this observational study
Ultraviolet photochemistry of 2-bromothiophene explored using universal ionization detection and multi-mass velocity-map imaging with a PImMS2 sensor
This project is funded by EPSRC Programme Grant No. EP/L005913/1. The raw ion events data and calculation log files can be retrieved from the University of Bristolâs research data repository and can be accessed using the following DOI:10.5523/bris.k35bi3pqsdbh2b5moo2e3puxf.The ultraviolet photochemistry of 2-bromothiophene (C4H3SBr) has been studied across the wavelength range 265-245 nm using a velocity-map imaging (VMI) apparatus recently modified for multi-mass imaging and vacuum ultraviolet (VUV, 118.2 nm) universal ionization. At all wavelengths, molecular products arising from the loss of atomic bromine were found to exhibit recoil velocities and anisotropies consistent with those reported elsewhere for the Br fragment [J. Chem. Phys. 142, 224303 (2015)]. Comparison between the momentum distributions of the Br and C4H3S fragments suggests that bromine is formed primarily in its ground (2P3/2) spin-orbit state. These distributions match well at high momentum, but relatively fewer slow moving molecular fragments were detected. This is explained by the observation of a second substantial ionic product, C3H3+. Analysis of ion images recorded simultaneously for several ion masses and the results of high-level ab initio calculations suggest that this fragment ion arises from dissociative ionization (by the VUV probe laser) of the most internally excited C4H3S fragments. This study provides an excellent benchmark for the recently modified VMI instrumentation and offers a powerful demonstration of the emerging field of multi-mass VMI using event-triggered, high frame-rate sensors, and universal ionization.Publisher PDFPeer reviewe
Systematic literature review of determinants of sedentary behaviour in older adults:a DEDIPAC study
BACKGROUND: Older adults are the most sedentary segment of society and high sedentary time is associated with poor health and wellbeing outcomes in this population. Identifying determinants of sedentary behaviour is a necessary step to develop interventions to reduce sedentary time.
METHODS: A systematic literature review was conducted to identify factors associated with sedentary behaviour in older adults. Pubmed, Embase, CINAHL, PsycINFO and Web of Science were searched for articles published between 2000 and May 2014. The search strategy was based on four key elements: (a) sedentary behaviour and its synonyms; (b) determinants and its synonyms (e.g. correlates, factors); (c) types of sedentary behaviour (e.g. TV viewing, sitting, gaming) and (d) types of determinants (e.g. environmental, behavioural). Articles were included in the review if specific information about sedentary behaviour in older adults was reported. Studies on samples identified by disease were excluded. Study quality was rated by means of QUALSYST. The full review protocol is available from PROSPERO (PROSPERO 2014: CRD42014009823). The analysis was guided by the socio-ecological model framework.
RESULTS: Twenty-two original studies were identified out of 4472 returned by the systematic search. These included 19 cross-sectional, 2 longitudinal and 1 qualitative studies, all published after 2011. Half of the studies were European. The study quality was generally high with a median of 82 % (IQR 69-96 %) using Qualsyst tool. Personal factors were the most frequently investigated with consistent positive association for age, negative for retirement, obesity and health status. Only four studies considered environmental determinants suggesting possible association with mode of transport, type of housing, cultural opportunities and neighbourhood safety and availability of places to rest. Only two studies investigated mediating factors. Very limited information was available on contexts and sub-domains of sedentary behaviours.
CONCLUSION: Few studies have investigated determinants of sedentary behaviour in older adults and these have to date mostly focussed on personal factors, and qualitative studies were mostly lacking. More longitudinal studies are needed as well as inclusion of a broader range of personal and contextual potential determinants towards a systems-based approach, and future studies should be more informed by qualitative work
Understanding breast cancer patients' preference for two types of exercise training during chemotherapy in an unblinded randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Patient preference for group assignment may affect outcomes in unblinded trials but few studies have attempted to understand such preferences. The purpose of the present study was to examine factors associated with breast cancer patients' preference for two types of exercise training during chemotherapy.</p> <p>Methods</p> <p>Breast cancer patients (N = 242) completed a battery of tests including a questionnaire that assessed patient preference and the theory of planned behavior (TPB) prior to being randomized to usual care, resistance exercise training (RET), or aerobic exercise training (AET).</p> <p>Results</p> <p>99 (40.9%) participants preferred RET, 88 (36.4%) preferred AET, and 55 (22.7%) reported no preference. Past exercisers (p = 0.023), smokers (p = 0.004), and aerobically fitter participants (p = 0.005) were more likely to prefer RET. As hypothesized, participants that preferred AET had more favorable TPB beliefs about AET whereas participants that preferred RET had more favorable TPB beliefs about RET. In multivariate modeling, patient preference for RET versus AET was explained (R<sup>2 </sup>= .46; p < 0.001) by the difference in motivation for RET versus AET (ÎČ = .56; p < 0.001), smoking status (ÎČ = .13; p = 0.007), and aerobic fitness (ÎČ = .12; p = 0.018). Motivational difference between RET versus AET, in turn, was explained (R<sup>2 </sup>= .48; p < 0.001) by differences in instrumental attitude (ÎČ = .27; p < 0.001), affective attitude (ÎČ = .25; p < 0.001), and perceived behavioral control (ÎČ = .24; p < 0.001).</p> <p>Conclusion</p> <p>Breast cancer patients' preference for RET versus AET during chemotherapy was predicted largely by a difference in motivation for each type of exercise which, in turn, was based on differences in their beliefs about the anticipated benefits, enjoyment, and difficulty of performing each type of exercise during chemotherapy. These findings may help explain patient preference effects in unblinded behavioral trials.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier NCT00115713.</p
Life-Cycle Analysis: IDEA - An International Data Base for Ecoprofile Analysis. A Tool for Decision Makers
Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing
No abstract available
Granulocyte-macrophage colony-stimulating factor can stimulate macrophage proliferation via persistent activation of Na+/H+ antiport. Evidence for two distinct roles for Na+/H+ antiport activation
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Patient-Facing Mobile Apps to Support Physiotherapy Care: Protocol for a Systematic Review of Apps Within App Stores
BACKGROUND: Care delivered by physiotherapists aims to facilitate engagement in positive health behaviors by patients (eg, adherence to exercise). However, research suggests that behavioral interventions are frequently omitted from care. Hence, better understanding of strategies that can be used by physiotherapists to support patients to engage in positive behaviors is important and likely to optimize outcomes. Digital health interventions delivered via mobile apps are garnering attention for their ability to support behavior change. They have potential to incorporate numerous behavior change techniques (BCTs) to support goals of physiotherapy care, including but not limited to self-monitoring, goal setting, and prompts/alerts. Despite their potential to support physiotherapy care, much is still unknown about what apps are available to consumers, the BCTs they use, their quality, and their potential to change behaviors.
OBJECTIVE: The primary aim of this study is to systematically review the mobile apps available in app stores that are intended for use by patients to support physiotherapy care, including the BCTs within these apps. The secondary aims are to evaluate the quality and behavior change potential of these apps.
METHODS: A systematic review of mobile apps in app stores will be undertaken. This will be guided by recommendations for systematic reviews in line with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement but adapted to suit our app store search, consistent with similar systematic reviews of apps published in the Journal of Medical Internet Research. Apple Store and Google Play will be searched with a two-step search strategy, using terms relevant to physiotherapy, physiotherapists, and common physiotherapy care. Key eligibility criteria will include apps that are intended for use by patients and are self-contained or stand-alone without the need of additional wearable devices or other add-ons. Included apps will be coded for BCTs and rated for quality using the Mobile Application Rating Scale (MARS) and for potential to change behavior using the App Behavior Change Scale (ABACUS).
RESULTS: App store search and screening are expected to be completed in 2021. Data extraction and quality appraisal are expected to commence by November 2021. The study results are expected to be published in a subsequent paper in 2022.
CONCLUSIONS: Knowledge gained from this review will support clinical practice and inform research by providing a greater understanding of the quality of currently available mobile apps and their potential to support patient behavior change goals of physiotherapy care.
INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/29047
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