1,221 research outputs found
THE EFFECTS OF UNSTABLE EXERCISE TRAINING ON DYNAMIC BALANCE AND ABDOMINAL MUSCLE STRENGTH IN YOUNG FEMALE INDIVIDUALS
The purpose of this study was to evaluate the effects of unstable exercise training (UET) on dynamic balance (DB) and abdominal muscle strength in young female individuals. 22 healthy collegiate female students underwent a series of UET sessions. DB was evaluated by the 8-direction limits of stability (LOS) test. Abdominal strength was measured using 60s sit-up test. The UET combined the Both Sides Utilized (BOSU) and Swiss ball exercises, undertaken for 90mins, twice per week, for 6 weeks. The LOS performance in overall, forward, right, forward-left, backward-right, and backward-left at level 6 also significantly improved post-training. Further, significant improvements were observed in the 60s sit-up test. It is concluded that regular UET can improve DB and abdominal muscle strength in young female individuals
Pattern Registration Between Spherical Block-Copolymer Domains and Topographical Templates
Pattern registration is achieved in thin films of self-assembling block copolymers by using a topographical template to guide the positions of the polymer domains. The placement accuracy of the polymer domains is related to the edge roughness of the topographical template, and the ultimate placement accuracy is assessed (see Figure). For a block copolymer with spherical morphology, a registered polymer array is achieved by using a two-dimensional template
A COMPARISON OF BALANCE CONTROL BETWEEN JAVELIN THROWERS AND BASEBALL PITCHERS
This study evaluated the balance control in javelin throwers and baseball pitchers. Twenty-four athletes took part in the study and for each we measured their static and dynamic balance by Biodex Balance System, AMTl AccuSway force plate and Y balance test. The paired t-test was conducted to compare all the variables within subjects. The independent t-test was used to compare trail leg (TL) of baseball pitchers with propulsive leg (PL) of javelin throwers and stride leg (SL) of baseball pitchers with braking leg (BL) of javelin throwers. The results showed that there was no difference between the PL and BL in dynamic and static balance in javelin throwers. However, the dynamic balance in the TL was significantly better than the SL in baseball pitchers. The static balance in the PL in javelin throwers was also better than the TL in baseball pitchers. The research improves the understanding of balance control in elite athletes
Thermal Fatigue Resistance of Bionic Compacted Graphite Cast Iron Treated with the Twice Laser Process in Water
For enhancing the thermal fatigue resistance of bionic compacted graphite cast iron (CGI) lasertreated in water, the bionic units are treated twice with the laser to form an uneven bionic surface imitating the alternately soft and hard structure of a plant leaf, which can resist the tearing wind. The results show that this method, without changing the phase composition of the bionic unit, makes the austenite-to-martensite transformation more complete and the content of residual austenite is reduced, in addition, the microstructure coarsens and microhardness slightly turns lower. The twice laser process in water can effectively enhance the thermal fatigue resistance of bionic CGI by reducing the number of cracks in bionic units since the number of cross cracks on the bionic unit surface is the key factor, which affects their resistance to thermal crack propagation.For enhancing the thermal fatigue resistance of bionic compacted graphite cast iron (CGI) lasertreated in water, the bionic units are treated twice with the laser to form an uneven bionic surface imitating the alternately soft and hard structure of a plant leaf, which can resist the tearing wind. The results show that this method, without changing the phase composition of the bionic unit, makes the austenite-to-martensite transformation more complete and the content of residual austenite is reduced, in addition, the microstructure coarsens and microhardness slightly turns lower. The twice laser process in water can effectively enhance the thermal fatigue resistance of bionic CGI by reducing the number of cracks in bionic units since the number of cross cracks on the bionic unit surface is the key factor, which affects their resistance to thermal crack propagation
BETTER POSTURAL CONTROL DURING ACCURATE SHOOTING IN ELITE FEMALE BASKETBALL PLAYERS
The purpose of this study was to evaluate the differences of postural control (PC) during accurate and inaccurate shooting in elite female basketball players. 21 female professional basketball players recruited as subjects. The PC was evaluated by the Accusway as sway radius, velocity, radial and 95% area of the center of pressure (COP) during standard penalty line shooting. The results showed that the COP sway area during accurate shooting was significantly smaller than during inaccurate shooting (74.0 ± 37.9 vs. 110.6 ± 49.1, p < .05). Moreover, no significant differences were found between situations in the COP radius and velocity. This study found that during the accurate shooting, elite female basketball player had better PC which demonstrated that significant smaller COP sway area than inaccurate shooting
Topologically Stable Electroweak Flux Tube
We show that for a large range of parameters in a
electroweak theory with two Higgs doublets there may exist classically stable
flux tubes of Z boson magnetic field. In a limit of an extra global symmetry, these flux-tubes become topologically stable. These results are
automatically valid even if is gauged.Comment: 10 pages, LATE
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Characteristics of regional new particle formation in urban and regional background environments in the North China Plain
Long-term measurements of particle number size distributions were carried out both at an urban background site (Peking University, PKU) and a regional Global Atmospheric Watch station (Shangdianzi, SDZ) from March to November in 2008. In total, 52 new particle formation (NPF) events were observed simultaneously at both sites, indicating that this is a regional phenomenon in the North China Plain. On average, the mean condensation sink value before the nucleation events started was 0.025 s−1 in the urban environment, which was 1.6 times higher than that at regional site. However, higher particle formation and growth rates were observed at PKU (10.8 cm−3 s−1 and 5.2 nm h−1) compared with those at SDZ (4.9 cm−3 s−1 and 4.0 nm h−1). These results implied that precursors were much more abundant in the polluted urban environment. Different from the observations in cleaner environments, the background conditions of the observed particle homogeneous nucleation events in the North China Plain could be characterized as the co-existing of a stronger source of precursor gases and a higher condensational sink of pre-existing aerosol particles. Secondary aerosol formation following nucleation events results in an increase of particle mass concentration, particle light scattering coefficient, and cloud condensation nuclei (CCN) number concentration, with consequences on visibility, radiative effects, and air quality. Typical regional NPF events with significant particle nucleation rates and subsequent particle growth over a sufficiently long time period at both sites were chosen to investigate the influence of NPF on the number concentration of "potential" CCN. As a result, the NPF and the subsequent condensable growth increased the CCN number concentration in the North China Plain by factors in the range from 5.6 to 8.7. Moreover, the potential contribution of anthropogenic emissions to the CCN number concentration was more than 50%, to which more attention should be drawn in regional and global climate modeling, especially in the polluted urban areas
CP Violation in D0 - anti-D0 Oscillations: General Considerations and Applications to the Littlest Higgs Model with T-Parity
The observed D0 - anti-D0 oscillations provide a new stage in our search for
New Physics in heavy flavour dynamics. The theoretical verdict on the observed
values of x_D and y_D remains ambiguous: while they could be totally generated
by Standard Model dynamics, they could also contain a sizable or even leading
contribution from New Physics. Those oscillations are likely to enhance the
observability of CP violation as clear manifestations of New Physics. We
present general formulae for D0 - anti-D0 oscillations, concentrating on the
case of negligible direct CP violation. In particular we derive a general
formula for the time-dependent mixing-induced CP asymmetry in decays to a CP
eigenstate and its correlation with the semileptonic CP asymmetry a_SL(D0) in
D0(t) -> l nu K. We apply our formalism to the Littlest Higgs model with
T-parity, using the time-dependent CP asymmetry in D -> K_S phi as an example.
We find observable effects at a level well beyond anything possible with CKM
dynamics. Comparisons with CP violation in the K and B systems offer an
excellent test of this scenario and reveal the specific pattern of flavour and
CP violation in the D0 - anti-D0 system predicted by this model. We discuss a
number of charm decays that could potentially offer an insight in the dynamics
of CP violation in D decays. We also apply our formalism to B_s - anti-B_s
mixing.Comment: 26 pages, 9 png figures, 1 table. v2: eq. (A.1) corrected, minor
clarifying comments and few references added. v3: typos corrected, matches
published versio
Gene Expression of Human Lung Cancer Cell Line CL1-5 in Response to a Direct Current Electric Field
Background: Electrotaxis is the movement of adherent living cells in response to a direct current (dc) electric field (EF) of physiological strength. Highly metastatic human lung cancer cells, CL1-5, exhibit directional migration and orientation under dcEFs. To understand the transcriptional response of CL1-5 cells to a dcEF, microarray analysis was performed in this study. Methodology/Principal Findings: A large electric-field chip (LEFC) was designed, fabricated, and used in this study. CL1-5 cells were treated with the EF strength of 0mV/mm (the control group) and 300mV/mm (the EF-treated group) for two hours. Signaling pathways involving the genes that expressed differently between the two groups were revealed. It was shown that the EF-regulated genes highly correlated to adherens junction, telomerase RNA component gene regulation, and tight junction. Some up-regulated genes such as ACVR1B and CTTN, and some down-regulated genes such as PTEN, are known to be positively and negatively correlated to cell migration, respectively. The protein-protein interactions of adherens junction-associated EF-regulated genes suggested that platelet-derived growth factor (PDGF) receptors and ephrin receptors may participate in sensing extracellular electrical stimuli. We further observed a high percentage of significantly regulated genes which encode cell membrane proteins, suggesting that dcEF may directly influence the activity of cell membrane proteins in signal transduction. Conclusions/Significance: In this study, some of the EF-regulated genes have been reported to be essential whereas others are novel for electrotaxis. Our result confirms that the regulation of gene expression is involved in the mechanism of electrotactic response
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