939 research outputs found
Even Between-Lap Pacing Despite High Within-Lap Variation During Mountain Biking
Purpose: Given the paucity of research on pacing strategies during competitive events, this study examined
changes in dynamic high-resolution performance parameters to analyze pacing profiles during a multiple-lap
mountain-bike race over variable terrain. Methods: A global-positioning-system (GPS) unit (Garmin, Edge
305, USA) recorded velocity (m/s), distance (m), elevation (m), and heart rate at 1 Hz from 6 mountain-bike
riders (mean ± SD age = 27.2 ± 5.0 y, stature = 176.8 ± 8.1 cm, mass = 76.3 ± 11.7 kg, VO2max = 55.1 ± 6.0 mL
· kgâ1 . minâ1) competing in a multilap race. Lap-by-lap (interlap) pacing was analyzed using a 1-way ANOVA
for mean time and mean velocity. Velocity data were averaged every 100 m and plotted against race distance
and elevation to observe the presence of intralap variation. Results: There was no significant difference in lap times (P = .99) or lap velocity (P = .65) across the 5 laps. Within each lap, a high degree of oscillation in velocity was observed, which broadly reflected changes in terrain, but high-resolution data demonstrated additional
nonmonotonic variation not related to terrain. Conclusion: Participants adopted an even pace strategy across
the 5 laps despite rapid adjustments in velocity during each lap. While topographical and technical variations
of the course accounted for some of the variability in velocity, the additional rapid adjustments in velocity
may be associated with dynamic regulation of self-paced exercise
Psychosocial Factors Associated with Patterns of Smoking Surrounding Pregnancy in Fragile Families
Although research has documented factors associated with maternal smoking, we need a more in-depth understanding of the risk factors associated with changes in smoking behaviors during the postpartum period. We investigate smoking patterns during pregnancy and 1Â year postpartum as a function of relevant psychosocial factors. We use data on 3,522 postpartum mothers from the Fragile Families and Child Wellbeing Study to analyze the predictors of smoking among mothers who did not smoke during pregnancy but smoked at 1Â year postpartum, mothers who smoked both during pregnancy and postpartum, and mothers who did not smoke during either period. Our covariates are grouped into four categories of risk factors for smoking: socioeconomic status, health care, life course and health, and partner and social support. Postpartum mothers in our sample were more likely to smoke throughout or after their pregnancies if they had only a high school education or less, had a household income three or more times below the poverty line, had public or no health insurance, breastfed for less than 5Â months, were not married to the infantâs father, if the infantâs father currently smoked, and if they attended religious services less than once a week. Mental health problems were consistently associated with an increased risk of constant and postpartum smoking relative to non-smoking. Psychosocial factors play a role in postpartum smoking, but they have a stronger effect in predicting smoking that persists throughout pregnancy and the first year postpartum
Biologic predictors of clinical improvement in rituximab-treated refractory myositis Clinical rheumatology and osteoporosis
Background: To examine the longitudinal utility of a biomarker signature in conjunction with myositis autoantibodies (autoAbs) as predictors of disease improvement in refractory myositis patients treated with rituximab. Methods: In the RIM Trial, all subjects received rituximab on 2 consecutive weeks. Using start of treatment as baseline, serum samples (nâ=â177) were analyzed at baseline and after rituximab with multiplexed sandwich immunoassays to quantify type-1 IFN-regulated and other pro-inflammatory chemokines and cytokines. Biomarker scores were generated for the following pathways: type-1 IFN-inducible (IFNCK), innate, Th1, Th2, Th17 and regulatory cytokines. Myositis autoAbs (anti-synthetase nâ=â28, TIF-Îł nâ=â19, Mi-2 nâ=â25, SRP nâ=â21, MJ nâ=â18, non-MAA nâ=â24, unidentified autoantibody nâ=â9, and no autoantibodies nâ=â33) determined by immunoprecipitation at baseline, were correlated with outcome measures. Kruskal-Wallis rank sum tests were used for comparisons. Results: The mean (SD) values for muscle disease and physician global disease activity VAS scores (0-100 mm) were 46 (22) and 49 (19). IFNCK scores (median values) were higher at baseline in subjects with anti-synthetase (43), TIF1-Îł (31) and Mi-2 (30) compared with other autoAb groups (pâ30) and autoAb group (Mi-2, non-MAA, and undefined autoantibody) demonstrated the greatest clinical improvement based on muscle VAS (muscle-interaction pâ=â0.075). Conclusion: Biomarker signatures in conjunction with autoAbs help predict response to rituximab in refractory myositis. Biomarker and clinical responses are greatest at 16 weeks after rituximab
Nonlinear Dynamics of 3D Massive Gravity
We explore the nonlinear classical dynamics of the three-dimensional theory
of "New Massive Gravity" proposed by Bergshoeff, Hohm and Townsend. We find
that the theory passes remarkably highly nontrivial consistency checks at the
nonlinear level. In particular, we show that: (1) In the decoupling limit of
the theory, the interactions of the helicity-0 mode are described by a single
cubic term -- the so-called cubic Galileon -- previously found in the context
of the DGP model and in certain 4D massive gravities. (2) The conformal mode of
the metric coincides with the helicity-0 mode in the decoupling limit. Away
from this limit the nonlinear dynamics of the former is described by a certain
generalization of Galileon interactions, which like the Galileons themselves
have a well-posed Cauchy problem. (3) We give a non-perturbative argument based
on the presence of additional symmetries that the full theory does not lead to
any extra degrees of freedom, suggesting that a 3D analog of the 4D
Boulware-Deser ghost is not present in this theory. Last but not least, we
generalize "New Massive Gravity" and construct a class of 3D cubic order
massive models that retain the above properties.Comment: 21 page
Effects of web-based electrocardiography simulation on strategies and learning styles
Objective: To identify the association between the use of web simulation electrocardiography and the learning approaches, strategies and styles of nursing degree students. Method: A descriptive and correlational design with a one-group pretestâ posttest measurement was used. The study sample included 246 students in a Basic and Advanced Cardiac Life Support nursing class of nursing degree. Results: No significant differences between genders were found in any dimension of learning styles and approaches to learning. After the introduction of web simulation electrocardiography, significant differences were found in some item scores of learning styles: theorist (p < 0.040), pragmatic (p < 0.010) and approaches to learning. Conclusion: The use of a web electrocardiogram (ECG) simulation is associated with the development of active and reflexive learning styles, improving motivation and a deep approach in nursing students
Galileon Higgs vortices
Vortex solutions are topologically stable field configurations that can play
an important role in condensed matter, field theory, and cosmology. We
investigate vortex configuration in a 2+1 dimensional Abelian Higgs theory
supplemented by higher order derivative self-interactions, related with
Galileons. Our vortex solutions have features that make them qualitatively
different from well-known Abrikosov-Nielsen-Olesen configurations, since the
derivative interactions turn on gauge invariant field profiles that break axial
symmetry. By promoting the system to a 3+1 dimensional string configuration, we
study its gravitational backreaction. Our results are all derived within a
specific, analytically manageable system, and might offer indications for
understanding Galileonic interactions and screening mechanisms around
configurations that are not spherically symmetric, but only at most
cylindrically symmetric.Comment: 26 pages, 8 figure
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at â s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fbâ1 of â s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Observation of associated near-side and away-side long-range correlations in âsNN=5.02ââTeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (ÎÏ) and pseudorapidity (Îη) are measured in âsNN=5.02ââTeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1ââÎŒb-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<|Îη|<5) ânear-sideâ (ÎÏâŒ0) correlation that grows rapidly with increasing ÎŁETPb. A long-range âaway-sideâ (ÎÏâŒÏ) 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 Îη and ÎÏ) and ÎŁETPb dependence. The resultant ÎÏ correlation is approximately symmetric about Ï/2, and is consistent with a dominant cosâĄ2ÎÏ modulation for all ÎŁETPb ranges and particle pT
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