Amnestic Mild Cognitive Impairment and Early Alzheimer's Disease in an Asian Memory Clinic – Evidence for a Clinical Spectrum

Objectives: To determine if mild cognitive impairment (MCI) represents a continuum of cognitive and functional deficits. Methods: Clinical data of 164 subjects with no dementia (ND, n = 52), uncertain dementia (n = 69), and mild probable Alzheimer’s disease (AD, n = 43) were reviewed. Uncertain dementia patients were classified as pre-MCI (n = 11), early amnestic MCI (e-aMCI, n = 15) and late amnestic MCI (l-aMCI, n = 15). Cognitive assessments [Chinese Mini-Mental State Examination (CMMSE) and a validated neuropsychological battery], functional assessments (Lawton’s scale for instrumental activities of daily living) and neuroimaging (ischemic lesions and medial temporal lobe atrophy) were reviewed. Results: ND, aMCI and mild AD subjects demonstrated a significant trend for worsening performance for all cognitive and functional measures (ANOVA, p Conclusions: Clinical delineation of aMCI allows the differentiation of those likely to progress for better correlation to biomarker development

Control of Ascaris infection by chemotherapy: which is the most cost-effective option?

Cost-effectiveness analysis is used to predict the optimal design of mass chemotherapy strategies in controlling Ascaris lumbricoides infection. The question of who to treat, how many to treat, and how often to treat are addressed using a population dynamic model of helminth transmission that assesses effectiveness in terms of disease reduction, combined with cost data from an actual control programme. Child-targeted treatment can be more cost-effective than population treatment in reducing the number of disease cases. The model also implies that, in the circumstances described here, enhancing coverage is a more cost-effective approach than increasing frequency of treatmen

Structure determination of PF3 adsorption on Cu(100) using X-ray standing waves

The local structure of the Cu(100)c(4x2)-PF3 adsorption phase has been investigated through the use of normal-incidence X-ray standing waves (NIXSW), monitored by P 1s and F 1s photoemission, together with P K-edge near-edge X-ray absorption fine structure (NEXAFS). NEXAFS shows the molecule to be oriented with its C3v symmetry axis essentially perpendicular to the surface, while the P NIXSW data show the molecule to be adsorbed in atop sites 2.37±0.04 Å above the surface, this distance corresponding to the Cu-P nearest-neighbour distance in the absence of any surface relaxation. F NIXSW indicates a surprisingly small height difference of the P and F atoms above the surface 0.44±0.06 Å, compared with the value expected for an undistorted gas-phase geometry of 0.77 Å, implying significant increases in the F-P-F bond angles. In addition, however, the F NIXSW data indicate that the molecules have a well-defined azimuthal orientation with a molecular mirror plane aligned in a substrate mirror plane, and with a small (5-10°) tilt of the molecule in this plane such that the two symmetrically-equivalent F atoms in each molecule are tilted down towards the surface

A polarized atomic hydrogen beam

We describe the design and operating characteristics of a simple polarized atomic hydrogen beam particularly suitable for applications to crossed beams experiments. In addition to experimental measurements, we present the results of detailed computer models, using Monte-Carlo ray tracing techniques, optical analogs, and phase-space methods, that not only provide us with a confirmation of our measurement, but also allow us to characterize the density, polarization, and atomic fraction of the beam at all points along its path. As a subsidiary result, we also present measurements of the relative and absolute efficiencies of the V/G Supavac mass analyzer for masses 1 and 2

Self-determined motivation in sport predicts anti-doping motivation and intention: A perspective from the trans-contextual model

Objectives: Motivation in sport has been frequently identified as a key factor of young athletes’ intention of doping in sport, but there has not been any attempt in scrutinizing the motivational mechanism involved. The present study applied the trans-contextual model of motivation to explain the relationship between motivation in a sport context and motivation and the social-cognitive factors (attitude, subjective norm, perceived behavioral control, and intention) from the theory of planned behavior (TPB) in an anti-doping context. Design: A cross-sectional survey was conducted. Methods: Questionnaire data was collected from 410 elite and sub-elite young athletes in Australia (Mean age [17.7 ± 3.9 yr], 55.4% male, Years in sport [9.1 ± 3.2]). We measured the key model variables of study in relation to sport motivation (Behavioral Regulation in Sport Questionnaire), and the motivation (adapted version of the Treatment Self-Regulation Questionnaire) and social cognitive patterns (the theory of planned behavior questionnaire) of doping avoidance. The data was analyzed by variance-based structural equation modeling with bootstrapping of 999 replications. Results: The goodness-of-fit of the hypothesized model was acceptable. The bootstrapped parameter estimates revealed that autonomous motivation and amotivation in sport were positively associated with the corresponding types of motivation for the avoidance of doping. Autonomous motivation, subjective norm, and perceived behavioral control in doping avoidance fully mediated the relationship between autonomous motivation in sport and intention for doping avoidance. Conclusions: The findings support the tenets of the trans-contextual model, and explain how motivation in sport is related to athletes’ motivation and intention with respect to anti-doping behaviors

An oncogenic role for sphingosine kinase 2

While both human sphingosine kinases (SK1 and SK2) catalyze the generation of the pleiotropic signaling lipid sphingosine 1-phosphate, these enzymes appear to be functionally distinct. SK1 has well described roles in promoting cell survival, proliferation and neoplastic transformation. The roles of SK2, and its contribution to cancer, however, are much less clear. Some studies have suggested an antiproliferative/ pro-apoptotic function for SK2, while others indicate it has a prosurvival role and its inhibition can have anti-cancer effects. Our analysis of gene expression data revealed that SK2 is upregulated in many human cancers, but only to a small extent (up to 2.5-fold over normal tissue). Based on these findings, we examined the effect of different levels of cellular SK2 and showed that high-level overexpression reduced cell proliferation and survival, and increased cellular ceramide levels. In contrast, however, low-level SK2 overexpression promoted cell survival and proliferation, and induced neoplastic transformation in vivo. These findings coincided with decreased nuclear localization and increased plasma membrane localization of SK2, as well as increases in extracellular S1P formation. Hence, we have shown for the first time that SK2 can have a direct role in promoting oncogenesis, supporting the use of SK2-specific inhibitors as anti-cancer agents.Heidi A. Neubauer, Duyen H. Pham, Julia R. Zebol, Paul A.B. Moretti, Amanda L. Peterson, Tamara M. Leclercq, Huasheng Chan, Jason A. Powell, Melissa R. Pitman, Michael S. Samuel, Claudine S. Bonder, Darren J. Creek, Briony L. Gliddon and Stuart M. Pitso

Type IIB Solutions with Interpolating Supersymmetries

We study type IIB supergravity solutions with four supersymmetries that interpolate between two types widely considered in the literature: the dual of Becker and Becker's compactifications of M-theory to 3 dimensions and the dual of Strominger's torsion compactifications of heterotic theory to 4 dimensions. We find that for all intermediate solutions the internal manifold is not Calabi-Yau, but has SU(3) holonomy in a connection with a torsion given by the 3-form flux. All 3-form and 5-form fluxes, as well as the dilaton, depend on one function appearing in the supersymmetry spinor, which satisfies a nonlinear differential equation. We check that the fields corresponding to a flat bound state of D3/D5-branes lie in our class of solutions. The relations among supergravity fields that we derive should be useful in studying new gravity duals of gauge theories, as well as possibly compactifications.Comment: 27pp, v2 REVTeX4, typographical fixes and minor clarifications, v3 added ref, modified discussion of RR axion slightl

Apparent soil electrical conductivity as an indicator of paddy soil productivity (Konduktiviti elektrik berkelihatan sebagai petunjuk produktiviti tanah padi)

Abstract Paddy soils are naturally heterogeneous in terms of their physico-chemical properties which influence rice productivity. Currently, uniform application of agricultural fertilizers for the entire field is not efficient and could result in either insufficient or excess nutrient supply. Good agricultural practices can be achieved if soil and nutrient variations within a farm are considered, and a soil-yield interrelationship is established. Simple, rapid and accurate methods to characterize these variations are needed. This study was conducted in MARDI Seberang Perai Research Station located at the northern part of Peninsular Malaysia. Soil samples were collected at regular grid spacing from the upper (0-20 cm) and lower (30 -50 cm) soil layers. These samples were analysed for their soil texture and chemical properties. Crop cutting test yields were taken at the same soil sampling locations. Geo-referenced apparent electrical conductivity (EC a ) measurements were obtained by using Veris 3100 cart equipped with a data logger and a differential global positioning system (DGPS). The relationship between grain yield and EC a was examined for three crop seasons in scatter plots. A boundary line using log-normal function was fitted to the upper edge of the data in the scatter plots. Significant relationships between potential grain yield and EC a were found with r 2 >0.58. The significant correlations of temporal soil EC a and measurements implied that soil EC a within field do not tend to change significantly over time. Comparison of potential yield (Y po ) and observed yield (Y ob ) led to classification of farm areas into different management zones and allows for discriminate management practices particularly to low yield areas due to less than ideal field conditions

Z boson pair production at LHC in a stabilized Randall-Sundrum scenario

We study the Z boson pair production at LHC in the Randall-Sundrum scenario with the Goldberger-Wise stabilization mechanism. It is shown that comprehensive account of the Kaluza-Klein graviton and radion effects is crucial to probe the model: The KK graviton effects enhance the cross section of $g g \to Z Z$ on the whole so that the resonance peak of the radion becomes easy to detect, whereas the RS effects on the $q\bar{q} \to Z Z$ process are rather insignificant. The $p_T$ and invariant-mass distributions are presented to study the dependence of the RS model parameters. The production of longitudinally polarized Z bosons, to which the SM contributions are suppressed, is mainly due to KK gravitons and the radion, providing one of the most robust methods to signal the RS effects. The $1 \sigma$ sensitivity bounds on $(\Lambda_\pi, m_\phi)$ with $k/M_{\rm Pl} =0.1$ are also obtained such that the effective weak scale $\Lambda_\pi$ of order 5 TeV can be experimentally probed.Comment: 28 pages, LaTex file, 18 eps figure