426 research outputs found

    Fun versus Practical: Physiological Responses and Preference of Exercise Equipment

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    The elliptical cross trainer has become a popular a mode of exercise, but can only be used indoors. The StreetStrider was designed as an outdoor elliptical-bike. PURPOSE: The purpose of this study is to determine whether the elliptical or the StreetStrider was more enjoyable, and to compare the physiological variables for energy expenditure, heart rate (HR), VO2, and Rate of Perceived Exertion (RPE). METHODS: Thirty participants (15 male, 15 female, mean age=22±2) from Cleveland State University exercised for 20 minutes at 75% of their age predicted maximal heart rate on the StreetStrider and elliptical. Energy expenditure was measured with a COSMED K4b metabolic system. Participants’ RPE was recorded every five minutes using the Borg Scale for Rate of Perceived Exertion. Data was analyzed using SPSS version 18. A paired sample t-test compared physiological responses. A one-way ANOVA analyzed gender differences. A significance level of .05 was used to determine significance. RESULTS: No significant differences were shown in energy expenditure (p=.930), HR (p=.098), or in average RPE (p=.529) between the exercise trials. A preference survey concluded that most subjects found the StreetStrider more enjoyable than the elliptical. CONCLUSION: The StreetStrider is more enjoyable than the elliptical and as effective in energy expenditure, and could serve as a substitute for the elliptical.https://engagedscholarship.csuohio.edu/u_poster_2014/1034/thumbnail.jp

    Comparison of Electronic and Mechanical Handgrip Devices in Lowering Blood Pressure

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    Hypertension causes billions of deaths per year (Millar et al., 2013). The Zona PlusTM is an expensive tool designed to lower blood pressure (BP) using isometric exercise. This exercise may be achieved using a less expensive Handgrip Dynamometer. PURPOSE: The purpose of this research is to determine if the Zona or Handgrip Dynamometer is more efficient at lowering BP and most cost effective for patients. METHODS: Twenty subjects used the Zona and twenty subjects used the dynamometer three times per week for six weeks. BP was taken once per week prior to the treatment. A maximum voluntary contraction (MVC) was recorded for each hand before every treatment. Participants were required to hold the handgrip at 30% of their MVC for four two-minute contractions. A paired samples T test was used to analyze changes in participants’ BP. A one-way ANOVA was used to compare the BP changes between the Zona and the Handgrip. RESULTS: The results indicated no significant changes in participants’ pre- and post- treatment after training when using the Zona for either stolic (p=0.225) or diastolic BP (p=1.000). There was also no significant difference in participants’ post treatment systolic BP (p=0.199), however, the post treatment for diastolic increased significantly (p=0.027 BP between those that used the Zona PlusTM and Handgrip Dynamometer. CONCLUSION: Though the Dynamometer is more cost efficient, neither the Zona nor the Dynamometer resulted in lowered BP.https://engagedscholarship.csuohio.edu/u_poster_2014/1037/thumbnail.jp

    Low-temperature electron dephasing time in AuPd revisited

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    Ever since the first discoveries of the quantum-interference transport in mesoscopic systems, the electron dephasing times, τϕ\tau_\phi, in the concentrated AuPd alloys have been extensively measured. The samples were made from different sources with different compositions, prepared by different deposition methods, and various geometries (1D narrow wires, 2D thin films, and 3D thickfilms) were studied. Surprisingly, the low-temperature behavior of τϕ\tau_\phi inferred by different groups over two decades reveals a systematic correlation with the level of disorder of the sample. At low temperatures, where τϕ\tau_\phi is (nearly) independent of temperature, a scaling τϕmaxDα\tau_\phi^{\rm max} \propto D^{-\alpha} is found, where tauϕmaxtau_\phi^{\rm max} is the maximum value of τϕ\tau_\phi measured in the experiment, DD is the electron diffusion constant, and the exponent α\alpha is close to or slightly larger than 1. We address this nontrivial scaling behavior and suggest that the most possible origin for this unusual dephasing is due to dynamical structure defects, while other theoretical explanations may not be totally ruled out.Comment: to appear in Physica E, Proceedings for the International Seminar and Workshop "Quantum Coherence, Noise, and Decoherence in Nanostructures", 15-26 May 2006, Dresde

    Edge effects in a frustrated Josephson junction array with modulated couplings

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    A square array of Josephson junctions with modulated strength in a magnetic field with half a flux quantum per plaquette is studied by analytic arguments and dynamical simulations. The modulation is such that alternate columns of junctions are of different strength to the rest. Previous work has shown that this system undergoes an XY followed by an Ising-like vortex lattice disordering transition at a lower temperature. We argue that resistance measurements are a possible probe of the vortex lattice disordering transition as the linear resistance RL(T)A(T)/LR_{L}(T)\sim A(T)/L with A(T)(TTcI) A(T) \propto (T-T_{cI}) at intermediate temperatures TcXY>T>TcIT_{cXY}>T>T_{cI} due to dissipation at the array edges for a particular geometry and vanishes for other geometries. Extensive dynamical simulations are performed which support the qualitative physical arguments.Comment: 8 pages with figs, RevTeX, to appear in Phys. Rev.

    Radiological response heterogeneity is of prognostic significance in metastatic renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy

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    Background: Response evaluation criteria in solid tumours (RECIST) is widely used to assess tumour response but is limited by not considering disease site or radiological heterogeneity (RH). Objective: To determine whether RH or disease site has prognostic significance in patients with metastatic clear-cell renal cell carcinoma (ccRCC). Design, setting, and participants: A retrospective analysis was conducted of a second-line phase II study in patients with metastatic ccRCC (NCT00942877), evaluating 138 patients with 458 baseline lesions. Intervention: The phase II trial assessed vascular endothelial growth factor-targeted therapy ± Src inhibition. Outcome measurements and statistical analysis: RH at week 8 was assessed within individual patients with two or more lesions to predict overall survival (OS) using Kaplan-Meier method and Cox regression model. We defined a high heterogeneous response as occurring when one or more lesion underwent a ≥10% reduction and one or more lesion underwent a ≥10% increase in size. Disease progression was defined by RECIST 1.1 criteria. Results and limitations: In patients with a complete/partial response or stable disease by RECIST 1.1 and two or more lesions at week 8, those with a high heterogeneous response had a shorter OS compared to those with a homogeneous response (hazard ratio [HR] 2.01; 95% confidence interval [CI]: 1.39–2.92; p < 0.001). Response by disease site at week 8 did not affect OS. At disease progression, one or more new lesion was associated with worse survival compared with >20% increase in sum of target lesion diameters only (HR 2.12; 95% CI: 1.43–3.14; p < 0.001). Limitations include retrospective study design. Conclusions: RH and the development of new lesions may predict survival in metastatic ccRCC. Further prospective studies are required. Patient summary: We looked at individual metastases in patients with kidney cancer and showed that a variable response to treatment and the appearance of new metastases may be associated with worse survival. Further studies are required to confirm these findings

    Dynamics of tree diversity in undisturbed and logged subtropical rainforest in Australia

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    In subtropical rainforest in eastern Australia, changes in the diversity of trees were compared under natural conditions and eight silvicultural regimes over 35 years. In the treated plots basal area remaining after logging ranged from 12 to 58 m2 per ha. In three control plots richness differed little over this period. In the eight treated plots richness per plot generally declined after intervention and then gradually increased to greater than original diversity. After logging there was a reduction in richness per plot and an increase in species richness per stem in all but the lightest selective treatments. The change in species diversity was related to the intensity of the logging, however the time taken for species richness to return to pre-logging levels was similar in all silvicultural treatments and was not effected by the intensity of treatment. These results suggest that light selective logging in these forests mainly affects dominant species. The return to high diversity after only a short time under all silvicultural regimes suggests that sustainability and the manipulation of species composition for desired management outcomes is possible

    Gluons and the quark sea at high energies: distributions, polarization, tomography

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    This report is based on a ten-week program on "Gluons and the quark sea at high-energies", which took place at the Institute for Nuclear Theory in Seattle in Fall 2010. The principal aim of the program was to develop and sharpen the science case for an Electron-Ion Collider (EIC), a facility that will be able to collide electrons and positrons with polarized protons and with light to heavy nuclei at high energies, offering unprecedented possibilities for in-depth studies of quantum chromodynamics. This report is organized around four major themes: i) the spin and flavor structure of the proton, ii) three-dimensional structure of nucleons and nuclei in momentum and configuration space, iii) QCD matter in nuclei, and iv) Electroweak physics and the search for physics beyond the Standard Model. Beginning with an executive summary, the report contains tables of key measurements, chapter overviews for each of the major scientific themes, and detailed individual contributions on various aspects of the scientific opportunities presented by an EIC.Comment: 547 pages, A report on the joint BNL/INT/Jlab program on the science case for an Electron-Ion Collider, September 13 to November 19, 2010, Institute for Nuclear Theory, Seattle; v2 with minor changes, matches printed versio

    The Origin, Early Evolution and Predictability of Solar Eruptions

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    Coronal mass ejections (CMEs) were discovered in the early 1970s when space-borne coronagraphs revealed that eruptions of plasma are ejected from the Sun. Today, it is known that the Sun produces eruptive flares, filament eruptions, coronal mass ejections and failed eruptions; all thought to be due to a release of energy stored in the coronal magnetic field during its drastic reconfiguration. This review discusses the observations and physical mechanisms behind this eruptive activity, with a view to making an assessment of the current capability of forecasting these events for space weather risk and impact mitigation. Whilst a wealth of observations exist, and detailed models have been developed, there still exists a need to draw these approaches together. In particular more realistic models are encouraged in order to asses the full range of complexity of the solar atmosphere and the criteria for which an eruption is formed. From the observational side, a more detailed understanding of the role of photospheric flows and reconnection is needed in order to identify the evolutionary path that ultimately means a magnetic structure will erupt

    Fine-Scale Mapping of the 4q24 Locus Identifies Two Independent Loci Associated with Breast Cancer Risk

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    Background: A recent association study identified a common variant (rs9790517) at 4q24 to be associated with breast cancer risk. Independent association signals and potential functional variants in this locus have not been explored. Methods: We conducted a fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium. Results: Conditional analyses identified two independent association signals among women of European ancestry, represented by rs9790517 [conditional P = 2.51 × 10−4; OR, 1.04; 95% confidence interval (CI), 1.02–1.07] and rs77928427 (P = 1.86 × 10−4; OR, 1.04; 95% CI, 1.02–1.07). Functional annotation using data from the Encyclopedia of DNA Elements (ENCODE) project revealed two putative functional variants, rs62331150 and rs73838678 in linkage disequilibrium (LD) with rs9790517 (r2 ≥ 0.90) residing in the active promoter or enhancer, respectively, of the nearest gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factor–binding sites. Using data from both The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), we showed that rs62331150 was associated with level of expression of TET2 in breast normal and tumor tissue. Conclusion: Our study identified two independent association signals at 4q24 in relation to breast cancer risk and suggested that observed association in this locus may be mediated through the regulation of TET2. Impact: Fine-mapping study with large sample size warranted for identification of independent loci for breast cancer risk
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