THE STRATEGY OF MUSCULAR PRE-TENSION DURING INITIAL BLOCK PHASE IN SWIMMING GRAB START

The purpose of this study was to examine the effects of muscular pre-tension on swimming grab start performance. Eight well-trained subjects participated in this study. They were instructed to perform three strategies (stretch-shortening cycle, purely concentric with and with no muscular pre-tension) in grab start. Two Peak-Performance high-speed video cameras operating at 120 Hz and one Kistler force plate (600 Hz) mounted on the starting block were synchronized to collect the data. The results showed that the block time was significantly shorter and horizontal velocity of taking off was larger in muscular pre-tension than in stretch-shortening cycle strategy. Based on the results of the present study, it has been suggested that using muscular pre-tension strategy during initial block phase in grab start could add some benefits of decreasing time

BIOMECHANICAL ANALYSIS OF THE GRAB AND TRACK SWIMMING STARTS

The aim of this study was to compare the grab and track competitive swimming starts. Twelve male college competitive swimmers (six used the grab start and six the track start) participated in this study. Data were collected from two video cameras (60Hz) above water. The video data were digitized and analysis was performed with the Kwon3D Motion Analysis system. No significant differences existed between the two groups for flight time and distance, time to 12m, takeoff velocity and angle, entry velocity and angle and the center of mass at highest position above water. The track start had the centre of mass on the block more towards the rear and a shorter block time (

Joint Modeling with Censored Data and Group-based Trajectory Clustering

Trajectories of data are collected in a variety of settings and offer insight into the evolution of a disease in the fields of biomedical, human genetic, and public health research. However, trajectories based on serum biomarkers are often subjected to censoring due to the low sensitivity of the bioassay used to measure the marker. A joint modeling approach incorporating a binary outcome and bivariate normal longitudinal markers which subject to left-censoring is proposed as a method to understand the relationship between two longitudinal outcomes and a binary outcome. The binary outcome is fitted by a logistic regression model, and the bivariate correlated longitudinal data are modeled using a linear mixed model. The binary outcome and bivariate measurements are then joined through the random coefficients that are present in both models. A clinical example from the GenIMS study is given. The public health significance is that the proposed method examined the relationship of the two censored longitudinal biomarkers and the binary outcome in a joint modeling approach which provided for direct inference on the effects of the two censored longitudinal marker measurements on the evolution of the disease outcome in public health. Secondly, latent group-based trajectory modeling has been widely used to categorize individuals into several homogeneous trajectory groups. If there exist a small number of individuals who have unique trajectory patterns that are not similar to those observed in the rest of the population, the latent group-based trajectory modeling may end up identifying a larger number of latent trajectory groups with several groups containing very few individuals. Further analysis treating latent groups as a covariate may then cause unstable estimates of standard errors. The second part of this dissertation applies the idea of the tight clustering method in the human genetic field into group-based trajectory analysis to classify latent trajectory groups that are more efficient, and to classify miscellaneous individuals or outliers whose trajectory patterns are dissimilar to the patterns in the rest of the population. We used the Bayesian information criterion as the criterion for model selection. A clinical example from the Normal Aging PiB study is provided. The public health relevance is that this innovative method is able to identify latent trajectory groups and outliers making it widely applicable in any public health setting where longitudinal trajectories are of interest

Holographic duality between (2+1)(2+1)-d quantum anomalous Hall state and (3+1)(3+1)-d topological insulators

In this paper, we study $(2+1)$-dimensional quantum anomalous Hall states, i.e. band insulators with quantized Hall conductance, using the exact holographic mapping. The exact holographic mapping is an approach to holographic duality which maps the quantum anomalous Hall state to a different state living in $(3+1)$-dimensional hyperbolic space. By studying topological response properties and the entanglement spectrum, we demonstrate that the holographic dual theory of a quantum anomalous Hall state is a $(3+1)$-dimensional topological insulator. The dual description enables a new characterization of topological properties of a system by the quantum entanglement between degrees of freedom at different length scales.Comment: 10 pages, 9 figure

Fluoroquinolone therapy for bloodstream infections caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae

AbstractBackground/PurposeFor extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae infections, carbapenems are recommended as first line therapy, and clinical data on the therapeutic efficacy of fluoroquinolones (FQs) is limited. This study compares the efficacy of FQs and carbapenems for bloodstream infections caused by ESBL-producing Escherichia coli or Klebsiella pneumoniae.MethodsBetween 2008 and 2010, adults with ESBL-producing E. coli or K. pneumoniae bacteremia at two medical centers were reviewed. Adults receiving definitive FQ or carbapenem therapy were compared in a propensity score-matched analysis, and 30-day mortality was the primary endpoint.ResultsA total of 299 patients were eligible. Patients receiving a FQ (n = 24), either ciprofloxacin or levofloxacin, had a lower 30-day mortality rate than those with carbapenem therapy (8.3%, 2/24 vs. 23.3%, 64/275; p = 0.12). Multivariate regression analysis revealed that a critical illness [Pitt bacteremia score ≥ 4 points; odds ratio (OR), 7.09; p < 0.001], rapidly fatal underlying disease (OR, 5.73; p < 0.001), and hospital-associated infection (OR, 2.57; p = 0.01) were independently associated with 30-day mortality. By contrast, FQ definitive therapy was a protective factor compared with carbapenems (OR, 0.18; p = 0.04). There were 72 matched cases with carbapenem therapy in a propensity score-matched analysis, and a difference in the 30-day mortality rate of two groups was noted (8.3% vs. 29.2%; p = 0.05).ConslusionFor ESBL-producing E. coli or K. pneumoniae bacteremia, ciprofloxacin or levofloxacin, if active in vitro, can be considered as a carbapenem-sparing alternative

A neuronal death model: overexpression of neuronal intermediate filament protein peripherin in PC12 cells

<p>Abstract</p> <p>Background</p> <p>Abnormal accumulation of neuronal intermediate filament (IF) is a pathological indicator of some neurodegenerative disorders. However, the underlying neuropathological mechanisms of neuronal IF accumulation remain unclear. A stable clone established from PC12 cells overexpressing a GFP-Peripherin fusion protein (pEGFP-Peripherin) was constructed for determining the pathway involved in neurodegeneration by biochemical, cell biology, and electronic microscopy approaches. In addition, pharmacological approaches to preventing neuronal death were also examined.</p> <p>Results</p> <p>Results of this study showed that TUNEL positive reaction could be detected in pEGFP-Peripherin cells. Swollen mitochondria and endoplasmic reticulum (ER) were seen by electron microscopy in pEGFP-Peripherin cells on day 8 of nerve growth factor (NGF) treatment. Peripherin overexpression not only led to the formation of neuronal IF aggregate but also causes aberrant neuronal IF phosphorylation and mislocation. Western blots showed that calpain, caspase-12, caspase-9, and caspase-3 activity was upregulated. Furthermore, treatment with calpain inhibitor significantly inhibited cell death.</p> <p>Conclusions</p> <p>These results suggested that the cytoplasmic neuronal IF aggregate caused by peripherin overexpression may induce aberrant neuronal IF phosphorylation and mislocation subsequently trapped and indirectly damaged mitochondria and ER. We suggested that the activation of calpain, caspase-12, caspase-9, and caspase-3 were correlated to the dysfunction of the ER and mitochondria in our pEGFP-Peripherin cell model. The present study suggested that pEGFP-Peripherin cell clones could be a neuronal death model for future studies in neuronal IFs aggregate associated neurodegeneration.</p

THE COMPARSION OF CURVATURE RADIUS IN DIFFERENT PERFORMANCES

The purpose of this study was to compare the curvature radius of different performance (63.20m and 68.46m) of hammer throw. The subject, who is the present record holder in Taiwan, has 9 years of experience in hammer throw. Two Peak-Performance high-speed video cameras operating at 120Hz were used simultaneously to record the performances of the subject. The results indicated that the patterns were completely different between two performances of hammer throw. The better performance was more periodic than the other. Based on the results of this study, it has been suggested that other sport events that include aspects of rotation may also benefit by adjustment of the pattern from their curvature radius

Computational Procedure of Performance Assessment of Lifetime Index of Products for the Weibull Distribution with the Progressive First-Failure-Censored Sampling Plan

Process capability analysis has been widely applied in the field of quality control to monitor the performance of industrial processes. In practice, lifetime performance index CL is a popular means to assess the performance and potential of their processes, where L is the lower specification limit. This study will apply the large-sample theory to construct a maximum likelihood estimator (MLE) of CL with the progressive first-failure-censored sampling plan under the Weibull distribution. The MLE of CL is then utilized to develop a new hypothesis testing procedure in the condition of known L