2,371 research outputs found

    The Stem Cell Environment: Kinetics, Signaling and Markers

    Get PDF

    ACCURACY OF DIGITIZATION USING AUTOMATED AND MANUAL METHODS

    Get PDF
    The objective of this study was to determine the limits of accuracy of angular estimates produced by a computerized three-dimensional (3-D) motion measurement system using auto-digitization and manual digitization. We hypothesized that auto-digitization would produce more accurate and reliable estimates of angular data than manual digitization. Twelve reference angles were estimated from markers placed on a T-shaped pendulum. The pendulum’s angular velocity was systematically increased by changing the release position from four angles (0 -static, 45 , 90 , and 120 ). Angular estimates were compared over 20 frames for 10 trials at each release position using analysis of variance (ANOVA), and intra-class correlation coefficients (ICC’s) were used to estimate the variability among release positions. Two S-VHS camcorders were placed at 45 angles relative to the activity plane for filming, forming an inter-camera angle of 90 . The cameras operated at a film speed of 60 Hz, with a shutter speed of 1/500 second. A single 300-W flood light was positioned beside each camera to illuminate 1.90 cm diameter retro reflective markers. A 3-D calibration structure defined a calibration area 182.88 cm wide, 152.40 cm high, and 60.96 cm deep. Eighty independent film clips (4 angular velocities X 10 trials X 2 views) were manually digitized across 20 frames by five experienced digitizers. Data was transformed to 3-D coordinates using a DLT, and smoothed with a Butterworth second-order, low-pass recursive filter with a fc of 6 Hz. Mean errors of the angular estimates across trials and frames were within ±1.0 for each of the four release positions. ANOVA and a post-hoc Tukey test revealed the mean error of the auto-digitized trials was statistically larger (

    A randomised controlled intervention trial evaluating the efficacy of a Mediterranean dietary pattern on cognitive function and psychological wellbeing in healthy older adults: the MedLey study

    Get PDF
    Background: The incidence of age-related cognitive decline is rising considerably around the world. There is evidence from a number of recent cross-sectional and prospective studies indicating positive associations between the Mediterranean dietary pattern (MedDiet) and improved cognitive outcomes among the elderly including, reduced age-related cognitive decline and enhanced age-related cognitive performance. However, to date no study has validated these associations in healthy older adult populations (≥65 years and above) with randomised evidence. The main aim of the present study is to provide justified evidence regarding the efficacy of a MedDiet approach to safely reduce the onset of cognitive decline, and promote optimal cognitive performance among healthy older adults using rigorous, randomised intervention methodology. Methods/Design: MedLey is a 6-month, randomised controlled 2-cohort parallel group intervention trial, with initial assessment at baseline and repeated every three months. A sample of 166 healthy Australian men and women aged 65 years and above, with normal cognitive function and proficient in English language were recruited from metropolitan Adelaide, South Australia for the study. Participants randomly allocated to the experimental group are required to maintain an intervention dietary pattern based from the traditional Cretan MedDiet (i.e. vegetables, fruits, olive oil, legumes, fish, whole grain cereals, nuts and seeds and low consumption of processed foods, dairy products, red meat and vegetable oils) for six months, while those participants allocated to the control group are asked to maintain their customary lifestyle and diet. The primary outcome of interest is the quantitative difference in age-related cognitive performance, as measured by latent variables (cognitive constructs) sensitive to normal ageing and diet (i.e. speed of processing, memory, attention, executive functions, visual spatial and visuomotor ability). Secondary outcomes include change in biomarkers of inflammation, oxidative stress, lipid metabolism, glucose, insulin, blood flow velocity, and psychological well-being factors (i.e. stress, sleep, anxiety, depression). Discussion: To our knowledge this will be one of the first randomised clinical trials worldwide to provide evidence for the cause-effect relationship between the MedDiet and age-related cognitive function in a healthy older adult population (≥65 years and over).Alissa Knight, Janet Bryan, Carlene Wilson, Jonathan Hodgson and Karen Murph

    In Situ ATR-SEIRAS of Carbon Dioxide Reduction at a Plasmonic Silver Cathode.

    Get PDF
    Illumination of a voltage-biased plasmonic Ag cathode during CO2 reduction results in a suppression of the H2 evolution reaction while enhancing CO2 reduction. This effect has been shown to be photonic rather than thermal, but the exact plasmonic mechanism is unknown. Here, we conduct an in situ ATR-SEIRAS (attenuated total reflectance-surface-enhanced infrared absorption spectroscopy) study of a sputtered thin film Ag cathode on a Ge ATR crystal in CO2-saturated 0.1 M KHCO3 over a range of potentials under both dark and illuminated (365 nm, 125 mW cm-2) conditions to elucidate the nature of this plasmonic enhancement. We find that the onset potential of CO2 reduction to adsorbed CO on the Ag surface is -0.25 VRHE and is identical in the light and the dark. As the production of gaseous CO is detected in the light near this onset potential but is not observed in the dark until -0.5 VRHE, we conclude that the light must be assisting the desorption of CO from the surface. Furthermore, the HCO3- wavenumber and peak area increase immediately upon illumination, precluding a thermal effect. We propose that the enhanced local electric field that results from the localized surface plasmon resonance (LSPR) is strengthening the HCO3- bond, further increasing the local pH. This would account for the decrease in H2 formation and increase the CO2 reduction products in the light

    Experimental validation of a dimensional analysis of spheronisation of cylindrical extrudates

    Get PDF
    Extrusion–spheronisation is a widely used technique for the manufacture of pellets with high sphericity and narrow size distribution. A dimensionless framework for describing the evolution of pellet shape with spheronisation time is presented for the first time and is validated using new experimental data obtained with two families of materials: (i) microcrystalline cellulose (MCC)/water-based pastes with loadings of up to 15 wt.% calcium carbonate representing a ‘hard’ active pharmaceutical ingredient, and (ii) a lactose/MCC/water paste. The dimensional analysis of the pellet rounding stage identified the paste density and bulk yield strength, σY, as scaling quantities: σY was measured in separate extrusion tests and found to increase with increasing carbonate content. Larger paste strength gave longer spheronisation times and less spherical pellets for a given set of spheronisation conditions. The pellet aspect ratio was found to increase in a linear manner with the logarithm of spheronisation time, progressing towards an asymptotic final value. This behaviour, which is evident in old data sets but has not been discussed previously, is compared with two simple models. High speed imaging was also used to examine the collision behaviour of pellets during the breakage and rounding stages in spheronisation. This confirmed that the rounding phase was the rate-determining step. The velocities of a number of tracked pellets were consistently lower than the tip speed of the rotating friction plate, confirming previous findings in studies of beds of pellets.Microcrystalline cellulose for this final year student research project was kindly provided by MSD Devlab, Hoddesdon, UK. Support for M.P. Bryan from CERATIZIT GmbH and Sandvik Hyperion is gratefully acknowledged.This is the author accepted manuscript. The final version is available from Elsevier via https://doi.org/10.1016/j.powtec.2016.05.00

    CNN Architectures for Large-Scale Audio Classification

    Full text link
    Convolutional Neural Networks (CNNs) have proven very effective in image classification and show promise for audio. We use various CNN architectures to classify the soundtracks of a dataset of 70M training videos (5.24 million hours) with 30,871 video-level labels. We examine fully connected Deep Neural Networks (DNNs), AlexNet [1], VGG [2], Inception [3], and ResNet [4]. We investigate varying the size of both training set and label vocabulary, finding that analogs of the CNNs used in image classification do well on our audio classification task, and larger training and label sets help up to a point. A model using embeddings from these classifiers does much better than raw features on the Audio Set [5] Acoustic Event Detection (AED) classification task.Comment: Accepted for publication at ICASSP 2017 Changes: Added definitions of mAP, AUC, and d-prime. Updated mAP/AUC/d-prime numbers for Audio Set based on changes of latest Audio Set revision. Changed wording to fit 4 page limit with new addition

    Annual Progress Report, Study of Dynamic Rigidity of Marine Sediments

    Get PDF
    The report is divided into two tasks with each task summary being prepared by the principal investigators of that task. Task 1 includes a study of the dynamic rigidity, acoustic, and other engineering properties of marine sediments. Task 2 covers a study of upper ocean turbulence as related to acoustic measurements. (Author)http://archive.org/details/studyofdynamicri00and

    Infinite temperature limit of meson spectral functions calculated on the lattice

    Full text link
    We analyze the cut-off dependence of mesonic spectral functions calculated at finite temperature on Euclidean lattices with finite temporal extent. In the infinite temperature limit we present analytic results for lattice spectral functions calculated with standard Wilson fermions as well as a truncated perfect action. We explicitly determine the influence of `Wilson doublers' on the high momentum structure of the mesonic spectral functions and show that this cut-off effect is strongly suppressed when using an improved fermion action.Comment: 25 pages, 8 figure
    corecore