A comparison of Voxel compression mapping & longitudinal Voxel-Based morphometry

Clinical motivation: Serial brain imaging can reveal patterns of change over time with important clinical implications for neurodegenerative disease [1]. We investigate the performance of four analysis methods, in terms of a comparison of 20 patients with probable AD to 20 age- and sex-matched controls, characterising differences in change from baseline to later scans

Development of an in-field voltammetric method for the determination of barium

This work presents a reliable, cost-effective, rapid and infield voltammetric method for the detection of barium. The optimized method consists of an ultrathin mercury film deposited in-situ on a glassy carbon electrode in 0.02 M potassium chloride without deoxygenation; a deposition potential of -2500 mV, pulse height = 50 mV, step duration = 10 ms and a scan rate of 100 mV/s using differential pulse anodic stripping voltammetry (DP-ASV). The linear working range for barium was determined to be 5 – 80 μg/L (r2 = 0.997), and limit of detection (LOD) was 1.6 μg/L, for 30 sec deposition time. Percent relative standard deviation for 10 measurements performed at 20 μg/L was 5.8%. Application of the method allowed for the quantitative determination of barium concentration in a variety of waters, brake pad dust and gunshot residue (GSR) samples. Comparative analysis of sample results from DP-ASV with inductively-coupled plasma mass spectroscopy (ICP-MS) showed a mean percent difference of 1.8%. The method also permitted the simultaneous measurement of barium and lead, crucial for GSR samples

Longitudinal multivariate tensor- and searchlight-based morphometry using permutation testing

Tensor based morphometry [1] was used to detect statistically significant regions of neuroanatomical change over time in a comparison between 36 probable Alzheimer's Disease patients and 20 age- and sexmatched controls. Baseline and twelve-month repeat Magnetic Resonance images underwent tied spatial normalisation [10] and longitudinal high-dimensional warps were then estimated. Analyses involved univariate and multivariate data derived from the longitudinal deformation fields. The most prominent findings were expansion of the fluid spaces, and contraction of the hippocampus and temporal region. Multivariate measures were notably more powerful, and have the potential to identify patterns of morphometric difference that would be overlooked by conventional mass-univariate analysis

The Kinematics of Forearm Passing in Low Skilled and High Skilled Volleyball Players

Passing may well be the least glamorous of all volleyball techniques. It is usually appreciated only by players and coaches who realize its importance. Since the advent of the forearm pass in the 1950's, many volleyball coaches at all levels of play, find themselves spending an inordinate amount of practice time in perfecting this skill. Some of the variables that make it difficult to successfully pass the ball are the varying ball speeds, angles, and unpredictable flight paths associated with float serves and block deflections. Every offensive play begins with a pass. The flow of the match is very much influenced by the serve reception which mainly is done with a forearm pass. Bad receptions prevent quick combination attacks which many teams rely on in today's game. Today's quick paced game has created an even greater need for exact, consistent passing. The goal in today's game is to isolate hitters against only one blocker. Pinpoint passing accuracy is required so that the setter has a choice of several quick play-sets and is not forced to always go outside where a double block is waiting. In higher levels of play forearm passing is often executed with low passing angles and a quick delivery to the setter in order to speed up the offensive pace and decrease the defense's time to set up effectively against the attack. Few studies (Koenh, 1978; Rauh, 1972; Plunket, 1969) have investigated the kinematics of the forearm pass and no published research has been identified that has studied passing in both high and low skilled passers. The purposes of this study were to produce a kinematic profile of low skilled and high skilled volleyball players on the forearm pass. The resulting profile will be a significant step in the development of sound coaching techniques

Abstraction and Generalization in Conceptual Design Process: Involving Safety Principles in TRIZ-SDA Environment

Abstraction and generalization are the processes of facilitating a specific problem to help designers solve problems efficiently. Abstraction and generalization reduce complexity and increase creativity. Both abstraction and generalization guide designers to focus on the key factors of a problem towards producing a broader solution perspective. This paper aims to discuss the use of abstraction and generalization in the conceptual design process within the Theory of Inventive Problem Solving (TRIZ) environment, specifically, in TRIZ-SDA (Systematic Design Approach), which was developed to increase the understanding of safety principles in the conceptual design process. In addition, the aspects of abstraction and generalization advantages, their implementation in the design process, safety constraints and comparisons between abstraction and generalization are also reviewed. A case study of an aircraft component is used as the example in conducting abstraction and generalization in the safety approach

Formation and structural characterization of Ni nanoparticles embedded in SiO₂

Face-centered cubic Ni nanoparticles were formed in SiO₂ by ion implantation and thermal annealing. Small-angle x-ray scattering in conjunction with transmission electron microscopy was used to determine the nanoparticle size as a function of annealing temperature, whereas the local atomic structure was measured with x-ray absorption spectroscopy. The influence of finite-size effects on the nanoparticle structural properties was readily apparent and included a decrease in coordination number and bond length and an increase in structural disorder for decreasing nanoparticle size. Such results are consistent with the non-negligible surface-to-volume ratio characteristic of nanoparticles. In addition, temperature-dependent x-ray absorption spectroscopy measurements showed the mean vibrational frequency (as obtained from the Einstein temperature) decreased with decreasing nanoparticle size. This reduction was attributed to the greater influence of the loosely bound, under-coordinated surface atoms prevailing over the effects of capillary pressure, the former enhancing the low frequency modes of the vibrational density of statesThis work was financially supported by the Australian Synchrotron and the Australian Research Council with access to equipment provided by the Australian Nanofabrication Facility

Estimation of total intracranial volume - a comparison of methods

Total intracranial volume is a useful measure of inter-subject variability in pre-morbid brain volume, which has been recommended for inclusion in region of interest and voxel-based morphometric studies of dementia [1]. TIV can be estimated from structural MRI using time-consuming manual tracing or using automated methods. We show that recent improvements to the Statistical Parametric Mapping (SPM) software's unified segmentation method allow highly accurate and unbiased estimates to be obtained rapidly and without interaction

Developments of rubber material wear in conveyer belt system

Regular degradation of rubbers contribute frequent maintenance of conveyer belt system. This paper investigates wear rate and mechanisms of rubber and associated influential parameters based on the information available in literature. Abrasion, fatigue and roll formation are dominate wear mechanisms that are influenced by load, sliding velocity, hardness and friction. Correlations among influential parameters and their effect on rubber wear was established in details. Archad's equation does not work for rubber wear but researchers have proposed equations similar to that. Adhesion wear forms roll in the smooth surface when tear strength of rubber is low. Wear caused by adhesion is abrasion when surface texture is harsh. Hysteresis enhances fatigue wear if the substrate asperities are round or blunt

The importance of radio sources in accounting for the highest mass black holes

The most massive black holes lie in the most massive elliptical galaxies, and at low-z all radio-loud AGNs lie in giant ellipticals. This strongly suggests a link between radio-loudness and black hole mass. We argue that the increase in the radio-loud fraction with AGN luminosity in optically-selected quasar samples is consistent with this picture. We also use the ratio of black holes today to quasars at z~2 to conclude that the most bolometrically-luminous AGN, either radio-loud or radio quiet, are constrained to have lifetimes <~10^8 yr. If radio sources are associated with black holes of >~10^9 M_sun at all redshifts, then the same lifetime constraint applies to all radio sources with luminosities above L_5GHz ~ 10^24 W/Hz/sr.Comment: 6 pages, 2 figures. To appear in "Lifecycles of Radio Galaxies", ed J. Biretta et al., New Astronomy Review