387 research outputs found
EFFECTS OF BACKPACK LOADS ON NECK-TRUNK MUSCLE ACTIVATION AMONG OFFICE WORKERS
The main purposes of this study were to investigate the effect of weight carriage on necktrunk muscle activation during standing and walking among office workers and to compare electromyography activation between healthy and symptomatic office workers. Twenty-one participants were recruited. Three load trials (0%, 10%, and 15% BW) and two conditions (standing and walking) were encountered. Repeated measure ANOVA was used to test main effect of load and condition on kinetic data. There was a significant condition*load interaction on right trapezius. Significantly increasing activation of right abdominis was found as carrying 15% BW. There was a significant decrease on activation of left erector spinae while carrying 10% BW. Considering to electromyography data, we suggest the backpack load under 10% BW was suitable for office workers
Cross-Layer Optimization for Efficient Delivery of Scalable Video over WiMAX
Abstract. Video delivery application over wireless network has become increasingly important in recent years. For achieving more flexible video streams transmission, the scalable extension of the H.264/AVC standard has been developed, as well as which is combined with temporal, spatial and quality scalabilities to adapt efficiently the wireless bandwidth resource. In this paper, a cross-layer optimization for robust H.264 scalable video delivery over WiMAX network is proposed. In order to obtain a better delivery performance, the proposed method is used the hierarchical B-picture approach to classify video packets into different priorities. In the cross-layer optimization, the scalable video and packet classifier are proposed at the application layer, and the packet priority and queue allocation are used at the MAC layer. Finally, it is shown by NS2 simulations that the proposed method provides more stable wireless bandwidth and also achieves a better quality of the video streaming delivery
Factors Affecting Occupational Exposure to Needlestick and Sharps Injuries among Dentists in Taiwan: A Nationwide Survey
BACKGROUND: Although the risks of needlestick and sharps injuries (NSIs) for dentists are well recognized, most papers published only described the frequency of occupational exposure to NSIs. Less has been reported assessing factors contributing to exposure to NSIs. The purpose of this study was to update the epidemiology of NSIs among dentists in Taiwan and identify factors affecting NSIs in order to find preventive strategies. METHODOLOGY/PRINCIPAL FINDINGS: A nationwide survey was conducted in dentists at 60 hospitals and 340 clinics in Taiwan. The survey included questions about factors supposedly affecting exposure to NSIs, such as dentist and facility characteristics, knowledge and attitudes about infectious diseases, and practices related to infection control. Univariate and multivariate logistic regression analyses were conducted to determine the association between risk factors and exposure to NSIs. In total, 434 (74.8%) of 580 dentists returned the survey questionnaires, and 100 (23.0%) reported that they had experienced more than one NSI per week. Our data showed that the risk of occupational NSIs is similarly heightened by an older age (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.62-6.25), more years in practice (OR, 2.57; 95% CI, 1.41-4.69), working in clinics (OR, 1.73; 95% CI, 1.08-2.77), exhibiting less compliance with infection-control procedures (OR, 1.82; 95% CI, 1.04-3.18), having insufficient knowledge of blood-borne pathogens (OR, 1.67; 95% CI, 1.04-2.67), and being more worried about being infected by blood-borne pathogens (OR, 1.82; 95% CI, 1.05-3.13). CONCLUSIONS/SIGNIFICANCE: High rates of NSIs and low compliance with infection-control procedures highly contribute to the chance of acquiring a blood-borne pathogen infection and threaten occupational safety. This study reveals the possible affecting factors and helps in designing prevention strategies for occupational exposure to NSIs
Low-Level Laser-Accelerated Peripheral Nerve Regeneration within a Reinforced Nerve Conduit across a Large Gap of the Transected Sciatic Nerve in Rats
This study proposed a novel combination of neural regeneration techniques for the repair of damaged peripheral nerves. A biodegradable nerve conduit containing genipin-cross-linked gelatin was annexed using beta-tricalcium phosphate (TCP) ceramic particles (genipin-gelatin-TCP, GGT) to bridge the transection of a 15 mm sciatic nerve in rats. Two trigger points were irradiated transcutaneously using 660 nm of gallium-aluminum arsenide phosphide (GaAlAsP) via laser diodes for 2 min daily over 10 consecutive days. Walking track analysis showed a significant improvement in sciatic functional index (SFI) (P<0.01) and pronounced improvement in the toe spreading ability of rats undergoing laser stimulation. Electrophysiological measurements (peak amplitude and area) illustrated by compound muscle action potential (CMAP) curves demonstrated that laser stimulation significantly improved nerve function and reduced muscular atrophy. Histomorphometric assessments revealed that laser stimulation accelerated nerve regeneration over a larger area of neural tissue, resulting in axons of greater diameter and myelin sheaths of greater thickness than that observed in rats treated with nerve conduits alone. Motor function, electrophysiological reactions, muscular reinnervation, and histomorphometric assessments all demonstrate that the proposed therapy accelerated the repair of transected peripheral nerves bridged using a GGT nerve conduit
Phosphorylation at Ser473 regulates heterochromatin protein 1 binding and corepressor function of TIF1beta/KAP1
<p>Abstract</p> <p>Background</p> <p>As an epigenetic regulator, the transcriptional intermediary factor 1β (TIF1β)/KAP1/TRIM28) has been linked to gene expression and chromatin remodeling at specific loci by association with members of the heterochromatin protein 1 (HP1) family and various other chromatin factors. The interaction between TIF1β and HP1 is crucial for heterochromatin formation and maintenance. The HP1-box, PXVXL, of TIF1β is responsible for its interaction with HP1. However, the underlying mechanism of how the interaction is regulated remains poorly understood.</p> <p>Results</p> <p>This work demonstrates that TIF1β is phosphorylated on Ser473, the alteration of which is dynamically associated with cell cycle progression and functionally linked to transcriptional regulation. Phosphorylation of TIF1β/Ser473 coincides with the induction of cell cycle gene <it>cyclin A2 </it>at the S-phase. Interestingly, chromatin immunoprecipitation demonstrated that the promoter of <it>cyclin A2 </it>gene is occupied by TIF1β and that such occupancy is inversely correlated with Ser473 phosphorylation. Additionally, when HP1β was co-expressed with TIF1β/S473A, but not TIF1β/S473E, the colocalization of TIF1β/S473A and HP1β to the promoters of <it>Cdc2 </it>and <it>Cdc25A </it>was enhanced. Non-phosphorylated TIF1β/Ser473 allowed greater TIF1β association with the regulatory regions and the consequent repression of these genes. Consistent with possible inhibition of TIF1β's corepressor function, the phosphorylation of the Ser473 residue, which is located near the HP1-interacting PXVXL motif, compromised the formation of TIF1β-HP1 complex. Finally, we found that the phosphorylation of TIF1β/Ser473 is mediated by the PKCδ pathway and is closely linked to cell proliferation.</p> <p>Conclusion</p> <p>The modulation of HP1β-TIF1β interaction through the phosphorylation/de-phosphorylation of TIF1β/Ser473 may constitute a molecular switch that regulates the expression of particular genes. Higher levels of phosphorylated TIF1β/Ser473 may be associated with the expression of key regulatory genes for cell cycle progression and the proliferation of cells.</p
Associations between child maltreatment, PTSD, and internet addiction among Taiwanese students
AbstractThis study examines (1) the associations between multiple types of child maltreatment and Internet addiction, and (2) the mediating effects of post-traumatic stress disorder (PTSD) on these associations. We collected data from a national proportionately stratified random sample of 6233 fourth-grade students in Taiwan in 2014. We conducted bivariate correlations and sets of multiple regression analyses to examine the associations between multiple types of maltreatment (5 types in total) and Internet addiction, and to identify the mediating role of PTSD. The results reveal that being male and experiencing abuse (psychological neglect, physical neglect, paternal physical violence, sexual violence) were associated with increased risk among children of developing PTSD and Internet addiction. Moreover, PTSD mediated the associations between multiple types of maltreatment (except maternal physical violence) and Internet addiction. This study demonstrates (1) the effects of multiple types of maltreatment on the PTSD and Internet addiction of children and (2) the importance of early prevention and intervention in addressing related public-health concerns
- …