BIOMECHANICAL VALIDATION OF TRANSFER ASSESSMENT INSTRUMENT (TAI) IN EVALUATING DIFFERENT INDEPENDENT TRANSFERS IN WHEELCHAIR USERS

Transfers are one of the most essential and physically demanding daily activities for wheelchair users (WUs). The Transfer Assessment Instrument (TAI) is the first tool to standardize the way clinicians evaluate transfer techniques and to help identify specific skills to target during transfer training. The study was to validate the function of the TAI, indicate the effects of transfer skills in performing toilet transfers in two different setups, and evaluate the immediate effects of individualized TAI-based structured transfer training. Up to twenty-six WUs performed transfers to a level-height bench and a toilet with a side and front setup while force plates, load cells, and a motion capture system recorded the biomechanics of their natural transferring skills. Their skills were simultaneously evaluated by two clinicians using the TAI. Logistic and multiple linear regression models were used to determine the relationships between TAI scores and the joint kinetic variables on both arms. Multivariate analysis of variance models were built to test biomechanical differences between using and non-using skill groups during toilet transfers with a side and front setup respectively. Wilcoxon signed-rank test was used to compare the differences of the biomechanical variables between pre and post TAI-based transfer training. The results showed that the completion of TAI skills was associated with lower resultant moments and/or their rates of rise at both shoulders and/or elbows (p<0.02). Some skills increased the moment magnitude or rate on the leading side (p<0.03). Compared to WUs who did not use skills, WUs who scooted forward in their wheelchair and used an appropriate handgrip and head-hip techniques had better shoulder positioning and lower joint forces and moments on both arms in toilet transfers with a side setup (p<0.04), and WUs who used close wheelchair positioning had significantly lower trailing arm loading (p=0.03) in a front setup. The TAI-based transfer training intervention improved the leading shoulder posture (p<0.04) and reduced the joint forces and moments and their rates on both shoulders and trailing elbow and wrist (p<0.05). Structured training and the routine practice of TAI skills is recommended to help reduce the risk of developing secondary injuries

Networks on Chips: Structure and Design Methodologies

The next generation of multiprocessor system on chip (MPSoC) and chip multiprocessors (CMPs) will contain hundreds or thousands of cores. Such a many-core system requires high-performance interconnections to transfer data among the cores on the chip. Traditional system components interface with the interconnection backbone via a bus interface. This interconnection backbone can be an on-chip bus or multilayer bus architecture. With the advent of many-core architectures, the bus architecture becomes the performance bottleneck of the on-chip interconnection framework. In contrast, network on chip (NoC) becomes a promising on-chip communication infrastructure, which is commonly considered as an aggressive long-term approach for on-chip communications. Accordingly, this paper first discusses several common architectures and prevalent techniques that can deal well with the design issues of communication performance, power consumption, signal integrity, and system scalability in an NoC. Finally, a novel bidirectional NoC (BiNoC) architecture with a dynamically self-reconfigurable bidirectional channel is proposed to break the conventional performance bottleneck caused by bandwidth restriction in conventional NoCs

Geographical heterogeneity and influenza infection within households

Although it has been suggested that schoolchildren vaccination reduces influenza morbidity and mortality in the community, it is unknown whether geographical heterogeneity would affect vaccine effectiveness

The Liquid Sensor Using Thin Film Bulk Acoustic Resonator with C-Axis Tilted AlN Films

Dual-mode thin film bulk acoustic resonator (TFBAR) devices are fabricated with c-axis tilted AlN films. To fabricate dual-mode TFBAR devices, the off-axis RF magnetron sputtering method for the growth of tilted piezoelectric AlN thin films is adopted. In this report, the AlN thin films are deposited with tilting angles of 15° and 23°. The frequency response of the TFBAR device with 23° tilted AlN thin film is measured to reveal its ability to provide dual-mode resonance. The sensitivities of the longitudinal and shear modes to mass loading are calculated to be 2295 Hz cm2/ng and 1363 Hz cm2/ng with the mechanical quality factors of 480 and 287, respectively. The sensitivities of the longitudinal and shear modes are calculated to be 0 and 15 Hz cm2/μg for liquid loading

The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion

BACKGROUND: The rear-wheel camber, defined as the inclination of the rear wheels, is usually used in wheelchair sports, but it is becoming increasingly employed in daily propulsion. Although the rear-wheel camber can increase stability, it alters physiological performance during propulsion. The purpose of the study is to investigate the effects of rear-wheel cambers on temporal-spatial parameters, joint angles, and propulsion patterns. METHODS: Twelve inexperienced subjects (22.3±1.6 yr) participated in the study. None had musculoskeletal disorders in their upper extremities. An eight-camera motion capture system was used to collect the three-dimensional trajectory data of markers attached to the wheelchair-user system during propulsion. All participants propelled the same wheelchair, which had an instrumented wheel with cambers of 0°, 9°, and 15°, respectively, at an average velocity of 1 m/s. RESULTS: The results show that the rear-wheel camber significantly affects the average acceleration, maximum end angle, trunk movement, elbow joint movement, wrist joint movement, and propulsion pattern. The effects are especially significant between 0° and 15°. For a 15° camber, the average acceleration and joint peak angles significantly increased (p < 0.01). A single loop pattern (SLOP) was adopted by most of the subjects. CONCLUSIONS: The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration

A Bayesian measurement error model for two-channel cell-based RNAi data with replicates

RNA interference (RNAi) is an endogenous cellular process in which small double-stranded RNAs lead to the destruction of mRNAs with complementary nucleoside sequence. With the production of RNAi libraries, large-scale RNAi screening in human cells can be conducted to identify unknown genes involved in a biological pathway. One challenge researchers face is how to deal with the multiple testing issue and the related false positive rate (FDR) and false negative rate (FNR). This paper proposes a Bayesian hierarchical measurement error model for the analysis of data from a two-channel RNAi high-throughput experiment with replicates, in which both the activity of a particular biological pathway and cell viability are monitored and the goal is to identify short hair-pin RNAs (shRNAs) that affect the pathway activity without affecting cell activity. Simulation studies demonstrate the flexibility and robustness of the Bayesian method and the benefits of having replicates in the experiment. This method is illustrated through analyzing the data from a RNAi high-throughput screening that searches for cellular factors affecting HCV replication without affecting cell viability; comparisons of the results from this HCV study and some of those reported in the literature are included.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS496 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Cdk5rap2 Interacts with Pericentrin to Maintain the Neural Progenitor Pool in the Developing Neocortex

Primary autosomal-recessive microcephaly (MCPH) and Majewski osteodysplastic primordial dwarfism type II (MOPDII) are both genetic diseases that result in decreased brain size at birth. MCPH is thought to arise from alterations in the size of the neural progenitor pool, but the cause of this defect has not been thoroughly explored. We find that one of the genes associated with MCPH, Cdk5rap2, is highly expressed in the neural progenitor pool and that its loss results in a depletion of apical progenitors and increased cell-cycle exit leading to premature neuronal differentiation. We link Cdk5rap2 function to the pericentriolar material protein pericentrin, loss of function of which is associated with MOPDII. Depletion of pericentrin in neural progenitors phenocopies effects of Cdk5rap2 knockdown and results in decreased recruitment of Cdk5rap2 to the centrosome. Our findings uncover a common mechanism, involving aberrations in the neurogenesis program, that may underlie the development of microcephaly in multiple diseases.National Institutes of Health (U.S.) (grant NS37007)Howard Hughes Medical Institute (Investigator