RMIT University

About: RMIT University is a education organization based out in Melbourne, Victoria, Australia. It is known for research contribution in the topics: Population & Health care. The organization has 40468 authors who have published 82923 publications receiving 1729499 citations. The organization is also known as: Royal Melbourne Institute of Technology & Melbourne Technical College.

Reliability and validity of the Biodex System 3 Pro Isokinetic Dynamometer velocity, torque and position measurements

Abstract: This study quantitatively assessed the mechanical reliability and validity of position, torque and velocity measurements of the Biodex System 3 isokinetic dynamometer. Trial-to-trial and day-to-day reliability were assessed during three trials on two separate days. To assess instrument validity, measurement of each variable using the Biodex System 3 dynamometer was compared to a criterion measure of position, torque and velocity. Position was assessed at 5° increments across the available range of motion of the dynamometer. Torque measures were assessed isometrically by hanging six different calibrated weights from the lever arm. Velocity was assessed (30°/s to 500°/s) across a 70° arc of motion by manually accelerating the weighted lever arm. With the exception of a systematic decrease in velocity at speeds of 300°/s and higher, the Biodex System 3 performed with acceptable mechanical reliability and validity on all variables tested.

A new dynamic approach for statistical optimization of GNSS radio occultation bending angles for optimal climate monitoring utility

Abstract: [1] Global Navigation Satellite System (GNSS)-based radio occultation (RO) is a satellite remote sensing technique providing accurate profiles of the Earth’s atmosphere for weather and climate applications. Above about 30km altitude, however, statistical optimization is a critical process for initializing the RO bending angles in order to optimize the climate monitoring utility of the retrieved atmospheric profiles. Here we introduce an advanced dynamic statistical optimization algorithm, which uses bending angles from multiple days of European Centre for Medium-range Weather Forecasts (ECMWF) short-range forecast and analysis fields, together with averaged-observed bending angles, to obtain background profiles and associated error covariance matrices with geographically varying background uncertainty estimates on a daily updated basis. The new algorithm is evaluated against the existing Wegener Center Occultation Processing System version 5.4 (OPSv5.4) algorithm, using several days of simulated MetOp and observed CHAMP and COSMIC data, for January and July conditions. We find the following for the new method’s performance compared to OPSv5.4: 1.) it significantly reduces random errors (standard deviations), down to about half their size, and leaves less or about equal residual systematic errors (biases) in the optimized bending angles; 2.) the dynamic (daily) estimate of the background error correlation matrix alone already improves the optimized bending angles; 3.) the subsequently retrievedrefractivityprofilesandatmospheric(temperature)profilesbenefit by improvederror characteristics,especiallyabove about 30km. Based on theseencouraging results, we work to employ similar dynamic error covariance estimation also for the observed bending angles and to apply the method to full months and subsequently to entire climate data records.

Intraneuronal Alzheimer Aβ42 Accumulates in Multivesicular Bodies and Is Associated with Synaptic Pathology

Abstract: A central question in Alzheimer's disease concerns the mechanism by which β-amyloid contributes to neuropathology, and in particular whether intracellular versus extracellular β-amyloid plays a critical role. Alzheimer transgenic mouse studies demonstrate brain dysfunction, as β-amyloid levels rise, months before the appearance of β-amyloid plaques. We have now used immunoelectron microscopy to determine the subcellular site of neuronal β-amyloid in normal and Alzheimer brains, and in brains from Alzheimer transgenic mice. We report that β-amyloid 42 localized predominantly to multivesicular bodies of neurons in normal mouse, rat, and human brain. In transgenic mice and human Alzheimer brain, intraneuronal β-amyloid 42 increased with aging and β-amyloid 42 accumulated in multivesicular bodies within presynaptic and especially postsynaptic compartments. This accumulation was associated with abnormal synaptic morphology, before β-amyloid plaque pathology, suggesting that intracellular accumulation of β-amyloid plays a crucial role in Alzheimer's disease.

Tricellulin constitutes a novel barrier at tricellular contacts of epithelial cells

Abstract: For epithelia to function as barriers, the intercellular space must be sealed. Sealing two adjacent cells at bicellular tight junctions (bTJs) is well described with the discovery of the claudins. Yet, there are still barrier weak points at tricellular contacts, where three cells join together. In this study, we identify tricellulin, the first integral membrane protein that is concentrated at the vertically oriented TJ strands of tricellular contacts. When tricellulin expression was suppressed with RNA interference, the epithelial barrier was compromised, and tricellular contacts and bTJs were disorganized. These findings indicate the critical function of tricellulin for formation of the epithelial barrier.

Waist circumference, waist-hip ratio and body mass index and their correlation with cardiovascular disease risk factors in Australian adults.

Abstract: Objectives To compare body mass index (BMI), waist circumference and waist–hip ratio (WHR) as indices of obesity and assess the respective associations with type 2 diabetes, hypertension and dyslipidaemia Design and setting A national sample of 11 247 Australians aged ≥25 years was examined in 2000 in a cross-sectional survey Main outcome measures The examination included a fasting blood sample, standard 2-h 75-g oral glucose tolerance test, blood pressure measurements and questionnaires to assess treatment for dyslipidaemia and hypertension BMI, waist circumference and WHR were measured to assess overweight and obesity Results The prevalence of obesity amongst Australian adults defined by BMI, waist circumference and WHR was 208, 305 and 158% respectively The unadjusted odds ratio for the fourth vs first quartile of each obesity measurement showed that WHR had the strongest relationship with type 2 diabetes, dyslipidaemia (women only) and hypertension Following adjustment for age, however, there was little difference between the three measures of obesity, with the possible exceptions of hypertension in women, where BMI had a stronger association, and dyslipidaemia in women and type 2 diabetes in men, where WHR was marginally superior Conclusions Waist circumference, BMI and WHR identified different proportions of the population, as measured by both prevalence of obesity and cardiovascular disease (CVD) risk factors Whilst WHR had the strongest correlations with CVD risk factors before adjustment for age, the three obesity measures performed similarly after adjustment for age Given the difficulty of using age-adjusted associations in the clinical setting, these results suggest that given appropriate cut-off points, WHR is the most useful measure of obesity to use to identify individuals with CVD risk factors