130 research outputs found

    The validity and reliability of the my jump 2 app for measuring the reactive strength index and drop jump performance.

    Get PDF
    BACKGROUND: This is the first study to independently assess the concurrent validity and reliability of the My Jump 2 app for measuring drop jump performance. It is also the first to evaluate the app's ability to measure the reactive strength index (RSI). METHODS: Fourteen male sport science students (age: 29.5±9.9 years) performed three drop jumps from 20 cm and 40 cm (totaling 84 jumps), assessed via a force platform and the My Jump 2 app. Reported metrics included reactive strength index, jump height, ground contact time, and mean power. Measurements from both devices were compared using the intraclass correlation coefficient (ICC), Pearson product moment correlation coefficient (r), Cronbach's alpha (α), coefficient of variation (CV) and Bland-Altman plots. RESULTS: Near perfect agreement was seen between devices at 20 cm for RSI (ICC=0.95) and contact time (ICC=0.99) and at 40 cm for RSI (ICC=0.98), jump height (ICC=0.96) and contact time (ICC=0.92); with very strong agreement seen at 20 cm for jump height (ICC=0.80). In comparison with the force plate the app showed good validity for RSI (20 cm: r=0.94; 40 cm; r=0.97), jump height (20 cm: r=0.80; 40 cm; r=0.96) and contact time (20 cm=0.96; 40 cm; r=0.98). CONCLUSIONS: The results of the present study show that the My Jump 2 app is a valid and reliable tool for assessing drop jump performance

    Microscopic Theory of Heterogeneity and Non-Exponential Relaxations in Supercooled Liquids

    Full text link
    Recent experiments and computer simulations show that supercooled liquids around the glass transition temperature are "dynamically heterogeneous" [1]. Such heterogeneity is expected from the random first order transition theory of the glass transition. Using a microscopic approach based on this theory, we derive a relation between the departure from Debye relaxation as characterized by the β\beta value of a stretched exponential response function ϕ(t)=e(t/τKWW)β\phi(t) =e^{-(t/ \tau_{KWW})^{\beta}}, and the fragility of the liquid. The β\beta value is also predicted to depend on temperature and to vanish as the ideal glass transition is approached at the Kauzmann temperature.Comment: 4 pages including 3 eps figure

    The Shapes of Cooperatively Rearranging Regions in Glass Forming Liquids

    Full text link
    The shapes of cooperatively rearranging regions in glassy liquids change from being compact at low temperatures to fractal or ``stringy'' as the dynamical crossover temperature from activated to collisional transport is approached from below. We present a quantitative microscopic treatment of this change of morphology within the framework of the random first order transition theory of glasses. We predict a correlation of the ratio of the dynamical crossover temperature to the laboratory glass transition temperature, and the heat capacity discontinuity at the glass transition, Delta C_p. The predicted correlation agrees with experimental results for the 21 materials compiled by Novikov and Sokolov.Comment: 9 pages, 6 figure

    Self generated randomness, defect wandering and viscous flow in stripe glasses

    Full text link
    We show that the competition between interactions on different length scales, as relevant for the formation of stripes in doped Mott insulators, can cause a glass transition in a system with no explicitly quenched disorder. We analytically determine a universal criterion for the emergence of an exponentially large number of metastable configurations that leads to a finite configurational entropy and a landscape dominated viscous flow. We demonstrate that glassines is unambiguously tied to a new length scale which characterizes the typical length over which defects and imperfections in the stripe pattern are allowed to wander over long times.Comment: 17 pages, 9 figure

    Monsoon-driven seasonal hypoxia along the northern coast of Oman

    Get PDF
    Dissolved oxygen and current observations from a cabled ocean observatory in the Sea of Oman show that the annual recurrence of coastal hypoxia, defined as dissolved oxygen concentrations ≤63 μM, is associated with the seasonal cycle of local monsoon winds. The observations represent the first long-term (5+ years) continuous moored observations off the northern Omani coast. During the summer/fall southwest (SW) monsoon season (Jun-Nov), winds in the Sea of Oman generate ocean currents that result in coastal upwelling of subsurface waters with low dissolved oxygen concentrations. The source of the poorly oxygenated water is the oxygen minimum zone (OMZ) in the Arabian Sea, a layer approximately 1000-m thick within the 100 to 1200 m depth range, where dissolved oxygen values approach anoxia. During the winter monsoon season (Dec-Feb), the Sea of Oman winds are from the northwest, forcing strong and persistent southeast currents. These winds generate oceanic downwelling conditions along the coastal ocean that ventilate waters at depth. Possible impacts of the monsoon-driven seasonal hypoxia on local fisheries and implications due to climate change are also discussed in this study

    Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers

    Get PDF
    Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

    Get PDF
    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    A framework for increasing the availability of life cycle inventory data based on the role of multinational companies

    Get PDF
    Purpose The aim of the paper is to assesses the role and effectiveness of a proposed novel strategy for Life Cycle Inventory (LCI) data collection in the food sector and associated supply chains. The study represents one of the first of its type and provides answers to some of the key questions regarding the data collection process developed, managed and implemented by a multinational food company across the supply chain. Methods An integrated LCI data collection process for confectionery products was developed and implemented by Nestlé, a multinational food company. Some of the key features includes: (1) management and implementation by a multinational food company, (2) types of roles to manage, provide and facilitate data exchange, (3) procedures to identify key products, suppliers and customers, (4) LCI questionnaire and cover letter, and (5) data quality management based on the pedigree matrix. Overall, the combined features in an integrated framework provides a new way of thinking about the collection of LCI data from the perspective of a multinational food company. Results The integrated LCI collection framework spanned across five months and resulted in 87 new LCI datasets for confectionery products from raw material, primary resource use, emission and waste release data collected from suppliers across 19 countries. The data collected was found to be of medium-to-high quality compared with secondary data. However, for retailers and waste service companies only partially completed questionnaires were returned. Some of the key challenges encountered during the collection and creation of data included: lack of experience, identifying key actors, communication and technical language, commercial compromise, confidentiality protection, and complexity of multi-tiered supplier systems. A range of recommendations are proposed to reconcile these challenges which include: standardisation of environmental data from suppliers, concise and targeted LCI questionnaires, and visualising complexity through drawings. Conclusions The integrated LCI data collection process and strategy has demonstrated the potential role of a multinational company to quickly engage and act as a strong enabler to unlock latent data for various aspects of the confectionery supply chain. Overall, it is recommended that the research findings serve as the foundations to transition towards a standardised procedure which can practically guide other multinational companies to considerably increase the availability of LCI data
    corecore