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Dara M Shearer, W Murray Thomson, Jonathan M Broadbent, Jim Mann, Richie Poulton
AIM: To examine associations between periodontitis and developmental trajectories of glycated haemoglobin (HbA1c) during the third and fourth decades in an initially healthy sample. MATERIALS AND METHODS: HbA1c data collected at ages 26, 32 and 38 in the prospective Dunedin Multidisciplinary Health and Development Study were used to assign study members (n=893) to trajectories applying group-based trajectory modelling (GBTM). The model allowed the statistical linking of baseline demographic, smoking and waist-height ratio covariates to group membership probability; and added a time-varying covariate (periodontitis) to the trajectories themselves to examine whether events that occurred during the course of the trajectory altered its course...
October 26, 2016: Journal of Clinical Periodontology
Jorge Barros, Susana Morales, Orietta Echávarri, Arnol García, Jaime Ortega, Takeshi Asahi, Claudia Moya, Ronit Fischman, María P Maino, Catalina Núñez
Objective: To analyze suicidal behavior and build a predictive model for suicide risk using data mining (DM) analysis. Methods: A study of 707 Chilean mental health patients (with and without suicide risk) was carried out across three healthcare centers in the Metropolitan Region of Santiago, Chile. Three hundred forty-three variables were studied using five questionnaires. DM and machine-learning tools were used via the support vector machine technique. Results: The model selected 22 variables that, depending on the circumstances in which they all occur, define whether a person belongs in a suicide risk zone (accuracy = 0...
October 20, 2016: Revista Brasileira de Psiquiatria
Michael J Dunn, Jennifer A Jackson, Stacey Adlard, Amanda S Lynnes, Dirk R Briggs, Derren Fox, Claire M Waluda
We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3...
2016: PloS One
Joanna P MacEwan, Felicia M Forma, Jason Shafrin, Ainslie Hatch, Darius N Lakdawalla, Jean-Pierre Lindenmayer
BACKGROUND: Poor medication adherence contributes to negative treatment response, symptom relapse, and hospitalizations in schizophrenia. Many health plans use claims-based measures like medication possession ratios or proportion of days covered (PDC) to measure patient adherence to antipsychotics. Classifying patients solely on the basis of a single average PDC measure, however, may mask clinically meaningful variations over time in how patients arrive at an average PDC level. OBJECTIVE: To model patterns of medication adherence evolving over time for patients with schizophrenia who initiated treatment with an oral atypical antipsychotic and, based on these patterns, to identify groups of patients with different adherence behaviors...
November 2016: Journal of Managed Care & Specialty Pharmacy
James C Lamsdell, Paul A Selden
Mass extinctions have altered the trajectory of evolution a number of times over the Phanerozoic. During these periods of biotic upheaval a different selective regime appears to operate, although it is still unclear whether consistent survivorship rules apply across different extinction events. We compare variations in diversity and disparity across the evolutionary history of a major Paleozoic arthropod group, the Eurypterida. Using these data, we explore the group's transition from a successful, dynamic clade to a stagnant persistent lineage, pinpointing the Devonian as the period during which this evolutionary regime shift occurred...
October 26, 2016: Evolution; International Journal of Organic Evolution
Xi Song
In recent years, sociological research investigating grandparent effects in three-generation social mobility has proliferated, mostly focusing on the question of whether grandparents have a direct effect on their grandchildren's social attainment. This study hypothesizes that prior research has overlooked family structure as an important factor that moderates grandparents' direct effects. Capitalizing on a counterfactual causal framework and multigenerational data from the Panel Study of Income Dynamics, this study examines the direct effect of grandparents' years of education on grandchildren's years of educational attainment and heterogeneity in the effects associated with family structure...
October 25, 2016: Demography
Arthur Caye, James Swanson, Anita Thapar, Margaret Sibley, Louise Arseneault, Lily Hechtman, L Eugene Arnold, Janni Niclasen, Terrie Moffitt, Luis Augusto Rohde
There is a renewed interest in better conceptualizing trajectories of attention-deficit/hyperactivity disorder (ADHD) from childhood to adulthood, driven by an increased recognition of long-term impairment and potential persistence beyond childhood and adolescence. This review addresses the following major issues relevant to the course of ADHD in light of current evidence from longitudinal studies: (1) conceptual and methodological issues related to measurement of persistence of ADHD, (2) estimates of persistence rate from childhood to adulthood and its predictors, (3) long-term negative outcomes of childhood ADHD and their early predictors, and (4) the recently proposed new adult-onset ADHD...
December 2016: Current Psychiatry Reports
Steven M Kurtz, Edmund Lau, Kevin L Ong, Jeffrey N Katz, Kevin J Bozic
No abstract text is available yet for this article.
October 25, 2016: Clinical Orthopaedics and related Research
Amber Kunkel, Forrest W Crawford, James Shepherd, Ted Cohen
OBJECTIVE: Extending the duration of isoniazid preventive therapy (IPT) among people living with HIV (PLHIV) may improve its effectiveness at both individual and population levels, but could also increase selective pressure in favor of isoniazid-resistant tuberculosis (TB) strains. The objective of this study was to determine the relative importance of these two effects. METHODS: Transmission dynamic model. DESIGN: We created a mathematical model of TB transmission incorporating HIV incidence and treatment, mixed strain latent TB infections, and four different phenotypes of TB drug resistance (pan-susceptible, isoniazid monoresistant, rifampicin monoresistant, and multidrug resistant)...
November 13, 2016: AIDS
Jun Dang, Fang-Fang Yin, Tao You, Chunhua Dai, Deyu Chen, Jing Wang
PURPOSE: Current approaches using deformable vector field (DVF) for motion-compensated 4D-cone beam CT (CBCT) reconstruction typically utilize an isotropically smoothed DVF between different respiration phases. Such isotropically smoothed DVF does not work well if sliding motion exists between neighboring organs. This study investigated an anisotropic motion modeling scheme by extracting organ boundary local motions (e.g., sliding) and incorporated them into 4D-CBCT reconstruction to optimize the motion modeling and reconstruction methods...
October 2016: Medical Physics
Svenja Ipsen, Ralf Bruder, Rick O'Brien, Paul J Keall, Achim Schweikard, Per R Poulsen
PURPOSE: With the trend in radiotherapy moving toward dose escalation and hypofractionation, the need for highly accurate targeting increases. While MLC tracking is already being successfully used for motion compensation of moving targets in the prostate, current real-time target localization methods rely on repeated x-ray imaging and implanted fiducial markers or electromagnetic transponders rather than direct target visualization. In contrast, ultrasound imaging can yield volumetric data in real-time (3D + time = 4D) without ionizing radiation...
October 2016: Medical Physics
Hui Wu, Zhi-Xin Duan, Shu-Hui Yin, Guang-Jiu Zhao
The quantum dynamics calculations of the H + HS (v = 0, j = 0) reaction on the (3)A' and (3)A″ potential energy surfaces (PESs) are performed using the reactant coordinate based time-dependent wave packet method. State-averaged and state-resolved results for both channels of the title reaction are presented in the 0.02-1.0 eV collision energy range and compared with those carried out with quasi-classical trajectory (QCT) method. Total integral cross sections (ICSs) for both channels are in excellent agreement with previous quantum mechanical (QM)-Coriolis coupling results while poorly agree with the QCT ICSs of the exchange channel, particularly near the threshold energy region...
September 28, 2016: Journal of Chemical Physics
David R Jacobson, Omar A Saleh
High spatial and temporal resolution magnetic tweezers experiments allow for the direct calibration of pulling forces applied to short biomolecules. In one class of experiments, a force is applied to a structured RNA or protein to induce an unfolding transition; when the force is maintained at particular values, the molecule can exhibit conformational switching between the folded and unfolded states or between intermediate states. Here, we analyze the degree to which common force calibration approaches, involving the fitting of model functions to the Allan variance or power spectral density of the bead trajectory, are biased by this conformational switching...
September 2016: Review of Scientific Instruments
Mark Wijzenbroek, Darcey Helstone, Jörg Meyer, Geert-Jan Kroes
We have performed calculations on the dissociative chemisorption of H2 on un-reconstructed and reconstructed Au(111) with density functional theory, and dynamics calculations on this process on un-reconstructed Au(111). Due to a very late barrier for dissociation, H2 + Au(111) is a candidate H2-metal system for which the dissociative chemisorption could be considerably affected by the energy transfer to electron-hole pairs. Minimum barrier geometries and potential energy surfaces were computed for six density functionals...
October 14, 2016: Journal of Chemical Physics
Rajib Biswas, William Carpenter, Gregory A Voth, Andrei Tokmakoff
Infrared (IR) spectroscopy of the water O-H stretch has been widely used to probe both the local hydrogen-bonding structure and dynamics of aqueous systems. Although of significant interest, the IR spectroscopy of excess protons in water remains difficult to assign as a result of extensive and strong intermolecular interactions in hydrated proton complexes. As an alternate approach, we develop a mixed quantum-classical model for the vibrational spectroscopy of the excess proton in isotopically dilute water that draws on frozen proton-water clusters taken from reactive molecular dynamics trajectories of the latest generation multi-state empirical valence bond proton model (MS-EVB 3...
October 21, 2016: Journal of Chemical Physics
Konrad Hinsen, Gerald R Kneller
Anomalous diffusion is characterized by its asymptotic behavior for t → ∞. This makes it difficult to detect and describe in particle trajectories from experiments or computer simulations, which are necessarily of finite length. We propose a new approach using Bayesian inference applied directly to the observed trajectories sampled at different time scales. We illustrate the performance of this approach using random trajectories with known statistical properties and then use it for analyzing the motion of lipid molecules in the plane of a lipid bilayer...
October 21, 2016: Journal of Chemical Physics
Oluwaseun O Mesele, Ward H Thompson
Approaches for directly calculating the activation energy for a chemical reaction from a simulation at a single temperature are explored with applications to both classical and quantum systems. The activation energy is obtained from a time correlation function that can be evaluated from the same molecular dynamics trajectories or quantum dynamics used to evaluate the rate constant itself and thus requires essentially no extra computational work.
October 7, 2016: Journal of Chemical Physics
Roger F Loring
Optically detected single-turnover measurements of biological and inorganic catalysts provide a detailed picture of structural and dynamical influences on catalytic activity. Measurement at the single-molecule level of catalysis of a fluorogenic reaction (or its reverse) yields a stochastic fluorescence trajectory reflecting the statistics of individual reaction and product dissociation events. Analysis of time correlations displayed by this trajectory reveals reaction details inaccessible in a bulk measurement of averaged dynamics...
October 7, 2016: Journal of Chemical Physics
Michał Wojciechowski, Marek Cieplak
A recent experimental study by Jobst et al. of stretching of a wild-type (WT) cohesin-dockerin complex has identified two kinds of the force-displacement patterns, with a single or double-peaked final rupture, which are termed "short" and "long" here. This duality has been interpreted as arising from the existence of two kinds of binding. Here, we analyze the separation of two cohesin-dockerin complexes of C. thermocellum theoretically. We use a coarse-grained structure-based model and the values of the pulling speeds are nearly experimental...
October 7, 2016: Journal of Chemical Physics
István Szabó, Gábor Czakó
We report a detailed quasiclassical trajectory study for the dynamics of the ground-state and CH/CD stretching-excited F(-) + CHD2Cl(vCH/CD = 0, 1) → Cl(-) + CHD2F, HF + CD2Cl(-), and DF + CHDCl(-) SN2, proton-, and deuteron-abstraction reactions using a full-dimensional global ab initio analytical potential energy surface. The simulations show that (a) CHD2Cl(vCH/CD = 1), especially for vCH = 1, maintains its mode-specific excited character prior to interaction, (b) the SN2 reaction is vibrationally mode-specific,...
October 7, 2016: Journal of Chemical Physics
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