687 research outputs found
BIOMECHANICAL ANALYSIS OF HIGH-LOW IMPACT AEROBIC DANCE AND STEP AEROBICS
The purpose of this study was to compare the kinematics and kinetics both in high-Iow impact aerobic dance and step aerobics. Six female subjects performed front knee lift movements under high-Iow impact aerobics and two-step heights (10, 20 cm) in step aerobics. One Peak high-speed camera (120 Hz) and one Kistler force plate (600 Hz) were synchronized to collect the data. An ANOVA for repeated measures was used to identify differences for each dependent variable. The result indicated that it is important to flex at the knee and ankle joints in order to absorb and reduce the shock in the landing phase. When compared to the low impact front knee lift, high impact front knee lift and two-step heights of step aerobics had significant shorter time to first peak impact force and higher values for first peak impact force, passive impact impulse, and total work
Production of N-acetyl-D-neuraminic acid using two sequential enzymes overexpressed as double-tagged fusion proteins
<p>Abstract</p> <p>Background</p> <p>Two sequential enzymes in the production of sialic acids, N-acetyl-D-glucosamine 2-epimerase (GlcNAc 2-epimerase) and <it>N</it>-acetyl-D-neuraminic acid aldolase (Neu5Ac aldolase), were overexpressed as double-tagged gene fusions. Both were tagged with glutathione S-transferase (GST) at the N-terminus, but at the C-terminus, one was tagged with five contiguous aspartate residues (5D), and the other with five contiguous arginine residues (5R).</p> <p>Results</p> <p>Both fusion proteins were overexpressed in <it>Escherichia coli </it>and retained enzymatic activity. The fusions were designed so their surfaces were charged under enzyme reaction conditions, which allowed isolation and immobilization in a single step, through a simple capture with either an anionic or a cationic exchanger (Sepharose Q or Sepharose SP) that electrostatically bound the 5D or 5R tag. The introduction of double tags only marginally altered the affinity of the enzymes for their substrates, and the double-tagged proteins were enzymatically active in both soluble and immobilized forms. Combined use of the fusion proteins led to the production of <it>N</it>-acetyl-D-neuraminic acid (Neu5Ac) from <it>N</it>-acetyl-D-glucosamine (GlcNAc).</p> <p>Conclusion</p> <p>Double-tagged gene fusions were overexpressed to yield two enzymes that perform sequential steps in sialic acid synthesis. The proteins were easily immobilized via ionic tags onto ionic exchange resins and could thus be purified by direct capture from crude protein extracts. The immobilized, double-tagged proteins were effective for one-pot enzymatic production of sialic acid.</p
Online assessment of patients' views on hospital performances using Rasch model's KIDMAP diagram
<p>Abstract</p> <p>Background</p> <p>To overcome the drawback of individual item-by-item box plots of disclosure for patient views on healthcare service quality, we propose to inspect interrelationships among items that measure a common entity. A visual diagram on the Internet is developed to provide thorough information for hospitals.</p> <p>Methods</p> <p>We used the Rasch rating scale model to analyze the 2003 English inpatient questionnaire data regarding patient satisfactory perception, which were collected from 169 hospitals, examined model-data fit, and developed a KIDMAP diagram on the Internet depicting the satisfaction level of each hospital and investigating aberrant responses with Z-scores and MNSQ statistics for individual hospitals. Differential item functioning (DIF) analysis was conducted to verify construct equivalence across types of hospitals.</p> <p>Results</p> <p>18 of the 45 items fit to the model's expectations, indicating they jointly defined a common construct and an equal-interval logit scale was achieved. The most difficult aspect for hospitals to earn inpatients' satisfaction were item 29 (staff told you about any medication side effects to watch when going home). No DIF in the 18-item questionnaire was found between types of hospitals, indicating the questionnaire measured the same construct across hospitals. Different types of hospitals obtained different levels of satisfaction. The KIDMAP on the Internet provided more interpretable and visualized message than traditional item-by-item box plots of disclosure.</p> <p>Conclusion</p> <p>After removing misfit items, we find that the 18-item questionnaire measures the same construct across types of hospitals. The KIDMAP on the Internet provides an exemplary comparison in quality of healthcare. Rasch analysis allows intra- and inter-hospital performances to be compared easily and reliably with each other on the Internet.</p
Light scattering properties beyond weak-field excitation in a few-atom system
In the study of optical properties of large atomic system, a weak laser
driving is often assumed to simplify the system dynamics by linearly coupled
equations. Here we investigate the light scattering properties of atomic
ensembles beyond weak-field excitation through cumulant expansion method. By
progressively incorporating higher-order correlations into the steady-state
equations, an enhanced accuracy can be achieved in comparison to the exact
solutions from solving a full density matrix. Our analysis reveals that, in the
regime of weak dipole-dipole interaction (DDI), the first-order expansion
yields satisfactory predictions for optical depth, while denser atomic
configurations necessitate consideration of higher-order correlations. As the
intensity of incident light increases, atom saturation effects become
noticeable, giving rise to significant changes of light transparency, energy
shift, and decay rate. This saturation phenomenon extends to subradiant atom
arrays even under weak driving conditions, leading to substantial deviations
from the linear model. Our findings demonstrate the potential of mean-field
models as good extensions to linear models as it balances both accuracy and
computational complexity, which can be an effective tool for probing optical
properties in large atom systems. However, the crucial role of higher-order
cumulants in large atom systems under finite laser field excitations remains
unclear since it is challenging theoretically owing to the
exponentially-increasing Hilbert space in such light-matter interacting
systems.Comment: 4 figure
BIOMECHANICAL ANALYSIS DURING COUNTERMOVEMENT JUMP IN CHILDREN AND ADULTS
This study was to examine the biomechanical characteristics of children and adults during countermovement jump. Seven children and seven adult males were recruited to the study. A Peak high-speed camera (120Hz) synchronized with a force plate (600Hz) were used to record vertical jumping action. The kinetic parameters were calculated by using inverse dynamic method. Results showed that the children had both immature joint function prior to propulsion and inadequate knee and ankle joints function during propulsion. It is concluded that a lack of form in jumping strategy was performed during vertical jumpings in the children's group in terms of the kinetic methods was performed. This information may be used in following studies about countermovement jump, avoiding some important information needed only by kinematic analysis, it will be more complete to apply kinetic analysis for children movement researches
Thoracoscopic plication for a huge thoracic meningocele in a patient with Neurofibromatosis
Intrathoracic meningoceles associated with neurofibromatosis type I are rare, and the optimal treatment is still unknown. Herein, we present the case of a 48-year-old Asian female with a huge thoracic meningocele associated with cutaneous neurofibromatosis type I and kyphoscoliosis of the thoracic spine. The large thoracic meningocele was successfully treated through thoracoscopic plication
Web-based computer adaptive assessment of individual perceptions of job satisfaction for hospital workplace employees
<p>Abstract</p> <p>Background</p> <p>To develop a web-based computer adaptive testing (CAT) application for efficiently collecting data regarding workers' perceptions of job satisfaction, we examined whether a 37-item Job Content Questionnaire (JCQ-37) could evaluate the job satisfaction of individual employees as a single construct.</p> <p>Methods</p> <p>The JCQ-37 makes data collection via CAT on the internet easy, viable and fast. A Rasch rating scale model was applied to analyze data from 300 randomly selected hospital employees who participated in job-satisfaction surveys in 2008 and 2009 via non-adaptive and computer-adaptive testing, respectively.</p> <p>Results</p> <p>Of the 37 items on the questionnaire, 24 items fit the model fairly well. Person-separation reliability for the 2008 surveys was 0.88. Measures from both years and item-8 job satisfaction for groups were successfully evaluated through item-by-item analyses by using <it>t</it>-test. Workers aged 26 - 35 felt that job satisfaction was significantly worse in 2009 than in 2008.</p> <p>Conclusions</p> <p>A Web-CAT developed in the present paper was shown to be more efficient than traditional computer-based or pen-and-paper assessments at collecting data regarding workers' perceptions of job content.</p
Decoration of graphene nanoribbons by transition-metal elements
Graphene is a famous truly two-dimensional (2D) material, possessing a
cone-like energy structure near the Fermi level and treated as a gapless
semiconductor. Its unique properties trigger researchers to find applications
of it. The gapless feature shrinks the development of graphene nanoelectronics.
Making one-dimensional (1D) strips of graphene nanoribbons (GNRs) could be one
of the promising routes to modulating the electronic and optical properties of
graphene. The electronic and optical properties of GNRs are highly sensitive to
the edge and width. The tunability in electronic and optical properties further
implies the possibilities of GNR application. However, the dangling bonds at
ribbon edges remain an open question in GNR systems. Various passivation at the
ribbon edge might change the essential physical properties. In this work,
transition-metal elements are considered as the guest atoms at the edges. The
geometric structure, energy bands, density of states, charge distribution, and
optical transitions are discussed
Applying Quantile Regression to Assess the Relationship between R&D, Technology Import and Patent Performance in Taiwan
[[abstract]]Electronics companies are facing global economic and trade competition. As patents can form an endowment shield that protects the development of corporate capabilities, companies are actively increasing their number of patents and attaching importance to technological research and development and patent management to achieve differentiated strategic effects. As such, patent layout and research and development (R&D) investment have become important strategic weapons for Taiwanese manufacturers, with which to enter the international market or compete among enterprises. This study first utilized the principal components analysis method to define patents in terms of the number of patents and the times patents are cited, with R&D defined in terms of expenditure and intensity. Furthermore, this study used a quantile regression model to visualize the relationship between R&D, technological imports, and patent performance in Taiwanese listed electronics companies. The empirical results show that technological imports in the second time-lag period require patents, while the effect on patents varies alongside industry characteristics. In addition, the empirical results found that the total assets, number of employees, and number of patent inventors are also factors that significantly affect patents. This research proposes that Taiwan’s listed electronics companies should expand their scale, increase their economic efficiency, maximize their resources, increase their patents, enhance their corporate value, boost their investor confidence, and improve their industry competitiveness.[[notice]]補ćŁĺ®Ś
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