3,754 research outputs found

    Evaluating metabolites in patients with major depressive disorder who received mindfulness-based cognitive therapy and healthy controls using short echo MRSI at 7 Tesla.

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    ObjectivesOur aim was to evaluate differences in metabolite levels between unmedicated patients with major depressive disorder (MDD) and healthy controls, to assess changes in metabolites in patients after they completed an 8-week course of mindfulness-based cognitive therapy (MBCT), and to exam the correlation between metabolites and depression severity.Materials and methodsSixteen patients with MDD and ten age- and gender-matched healthy controls were studied using 3D short echo-time (20 ms) magnetic resonance spectroscopic imaging (MRSI) at 7 Tesla. Relative metabolite ratios were estimated in five regions of interest corresponding to insula, anterior cingulate cortex (ACC), caudate, putamen, and thalamus.ResultsIn all cases, MBCT reduced severity of depression. The ratio of total choline-containing compounds/total creatine (tCr) in the right caudate was significantly increased compared to that in healthy controls, while ratios of N-acetyl aspartate (NAA)/tCr in the left ACC, myo-inositol/tCr in the right insula, and glutathione/tCr in the left putamen were significantly decreased. At baseline, the severity of depression was negatively correlated with my-inositol/tCr in the left insula and putamen. The improvement in depression severity was significantly associated with changes in NAA/tCr in the left ACC.ConclusionsThis study has successfully evaluated regional differences in metabolites for patients with MDD who received MBCT treatment and in controls using 7 Tesla MRSI

    Predicting College Student Gambling Frequency Using the Theory of Planned Behvior: Does the Theory Work Differently for Disordered and Non-Disordered Gamblers?

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    We examined whether disordered gambling moderates the prediction of gambling behavior via the theory of planned behavior (TPB; i.e., intentions, subjective norms, perceived behavioral control, and attitudes) among college students. A convenience sample of undergraduate students (N=377) at a large, Southeastern university who gambled in the past year completed a classroom-based survey. Approximately half of participants were male (n = 205; 54.4%), and the majority were Caucasian (n = 310; 83.8%). Gambling frequency, gambling problems and gambling-specific TPB constructs were assessed via a cross-sectional survey. A series of regression analyses were conducted to test the utility of the TPB model to predict gambling behavior (i.e., frequency) among (1) non-disordered gamblers (N=342) and (2) disordered gamblers (N=35). Moderation analyses indicated that disordered gamblers might not proceed through the thought processes that guide gambling in non-disordered gamblers. However, findings should be interpreted cautiously, as our study was limited by a small number of lifetime disordered gamblers

    Neogene stratigraphic architecture and tectonic evolution of Wanganui, King Country, and eastern Taranaki Basins, New Zealand

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    Analysis of the stratigraphic architecture of the fills of Wanganui, King Country, and eastern Taranaki Basins reveals the occurrence of five 2nd order Late Paleocene and Neogene sequences of tectonic origin. The oldest is the late Eocene-Oligocene Te Kuiti Sequence, followed by the early-early Miocene (Otaian) Mahoenui Sequence, followed by the late-early Miocene (Altonian) Mokau Sequence, all three in King Country Basin. The fourth is the middle Miocene to early Pliocene Whangamomona Sequence, and the fifth is the middle Pliocene-Pleistocene Rangitikei Sequence, both represented in the three basins. Higher order sequences (4th, 5th, 6th) with a eustatic origin occur particularly within the Whangamomona and Rangitikei Sequences, particularly those of 6th order with 41 000 yr periodicity

    Ares I-X Upper Stage Simulator Compartment Pressure Comparisons During Ascent

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    Predictions of internal compartment pressures are necessary in the design of interstage regions, systems tunnels, and protuberance covers of launch vehicles to assess potential burst and crush loading of the structure. History has proven that unexpected differential pressure loads can lead to catastrophic failure. Pressures measured in the Upper Stage Simulator (USS) compartment of Ares I-X during flight were compared to post-flight analytical predictions using the CHCHVENT chamber-to-chamber venting analysis computer program. The measured pressures were enveloped by the analytical predictions for most of the first minute of flight but were outside of the predictions thereafter. This paper summarizes the venting system for the USS, discusses the probable reasons for the discrepancies between the measured and predicted pressures, and provides recommendations for future flight vehicles

    HT2005-72581 HEAT TRANSFER DYNAMICS DURING TREATMENT OF PORT WINE STAIN BIRTHMARKS WITH MULTIPLE-INTERMITTENT CRYOGEN SPURTS AND LASER PULSES

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    ABSTRACT Port wine stain (PWS) is a congenital, progressive vascular malformation of human skin. Presently, all PWS patients are treated using single cryogen spurt and single laser pulse exposure (SCS-SLP), which does not produce complete lesion blanching in the vast majority of patients. In this study, the feasibility of applying multiple cryogen spurts intermittently with multiple laser pulse exposures (MCS-MLP) is studied numerically. Laser therapy of PWS was simulated with finite element heat diffusion and Monte Carlo light distribution models. Epidermal and thermal damage of PWS blood vessels of various diameters (50 -130 ÎŒm) were calculated with an Arrhenius-type kinetic model. The results show that the proposed MCS-MLP approach can provide sufficient epidermal protection while at the same time achieving higher core intravascular temperatures over longer periods of time. PWS patients may benefit from the MCS-MLP approach, depending on PWS vessels diameter

    LocalControl: An R Package for Comparative Safety and Effectiveness Research

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    The LocalControl R package implements novel approaches to address biases and confounding when comparing treatments or exposures in observational studies of outcomes. While designed and appropriate for use in comparative safety and effectiveness research involving medicine and the life sciences, the package can be used in other situations involving outcomes with multiple confounders. LocalControl is an open-source tool for researchers whose aim is to generate high quality evidence using observational data. The package implements a family of methods for non-parametric bias correction when comparing treatments in observational studies, including survival analysis settings, where competing risks and/or censoring may be present. The approach extends to bias-corrected personalized predictions of treatment outcome differences, and analysis of heterogeneity of treatment effect-sizes across patient subgroups

    Effect of surfactants on the thermoresponse of PNIPAM investigated in the brush geometry

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    Hypothesis: Anionic surfactants have been reported to interact with poly(N-isopropyl acrylamide) (PNIPAM), suppressing its thermoresponse. Scattering and NMR studies of the anionic sodium dodecylsulfate (SDS) system propose that the PNIPAM-surfactant interaction is purely hydrophobic. However, prior phenomenological investigations of a range of surfactant identities (anionic, cationic, nonionic) show that only anionic surfactants affect the thermoresponse and conformation of PNIPAM, implying that the hydrophilic head–group also contributes. Crucially, the phenomenological experiments do not measure the affinity of the tested surfactants to the polymer, only their effect on its behaviour. Experiments: We study the adsorption of six surfactants within a planar PNIPAM brush system, elucidating the polymer conformation, thermoresponse, and surfactant adsorption kinetics using ellipsometry, neutron reflectometry (NR), optical reflectometry and the quartz crystal microbalance technique. NR is used to measure the distribution of surfactants within the brush. Findings: We find that only anionic surfactants modify the structure and thermoresponse of PNIPAM, with the greater affinity of anionic surfactants for PNIPAM (relative to cationic and nonionic surfactants) being the primary reason for this behaviour. These results show that the surfactant head–group has a more critical role in mediating PNIPAM-surfactant interaction than previously reported. Taking inspiration from prior molecular dynamics work on the PEO-surfactant system, we propose an interaction mechanism for PNIPAM and SDS that reconciles evidence for hydrophobic interaction with the observed head–group-dependent affinity.</p

    Vortex Plastic Flow, B(x,y,H(t)),M(H(t)),Jc(B(t))B(x,y,H(t)), M(H(t)), J_c(B(t)), Deep in the Bose Glass and Mott-Insulator Regimes

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    We present simulations of flux-gradient-driven superconducting vortices interacting with strong columnar pinning defects as an external field H(t)H(t) is quasi-statically swept from zero through a matching field BϕB_{\phi}. We analyze several measurable quantities, including the local flux density B(x,y,H(t)) B(x,y,H(t)), magnetization M(H(t))M(H(t)), critical current Jc(B(t))J_{c}(B(t)), and the individual vortex flow paths. We find a significant change in the behavior of these quantities as the local flux density crosses BϕB_{\phi}, and quantify it for many microscopic pinning parameters. Further, we find that for a given pin density Jc(B)J_c(B) can be enhanced by maximizing the distance between the pins for B<Bϕ B < B_{\phi} .Comment: 4 pages, 4 PostScript Figure
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