2,175 research outputs found
Predicting the outcome of renal transplantation
ObjectiveRenal transplantation has dramatically improved the survival rate of hemodialysis patients. However, with a growing proportion of marginal organs and improved immunosuppression, it is necessary to verify that the established allocation system, mostly based on human leukocyte antigen matching, still meets today's needs. The authors turn to machine-learning techniques to predict, from donor-recipient data, the estimated glomerular filtration rate (eGFR) of the recipient 1 year after transplantation.DesignThe patient's eGFR was predicted using donor-recipient characteristics available at the time of transplantation. Donors' data were obtained from Eurotransplant's database, while recipients' details were retrieved from Charite Campus Virchow-Klinikum's database. A total of 707 renal transplantations from cadaveric donors were included.MeasurementsTwo separate datasets were created, taking features with <10% missing values for one and <50% missing values for the other. Four established regressors were run on both datasets, with and without feature selection.ResultsThe authors obtained a Pearson correlation coefficient between predicted and real eGFR (COR) of 0.48. The best model for the dataset was a Gaussian support vector machine with recursive feature elimination on the more inclusive dataset. All results are available at http://transplant.molgen.mpg.de/.LimitationsFor now, missing values in the data must be predicted and filled in. The performance is not as high as hoped, but the dataset seems to be the main cause.ConclusionsPredicting the outcome is possible with the dataset at hand (COR=0.48). Valuable features include age and creatinine levels of the donor, as well as sex and weight of the recipient
Using Prevention Science to Promote Children's Mental Health
This poster was presented at the International Counseling Psychology Conference in Chicago, IL, in March 2008.In a recent issue of The Counseling Psychologist, Hage et al. (2007) encouraged greater involvement of counseling psychologists in prevention related activities. To support these efforts, the authors described 15 principles of prevention science and provided aspirational guidelines to counseling psychologists. Although the call for counseling psychology participation in prevention activities is not new, the article was unique in connecting counseling psychology to the emerging field of prevention science and in offering suggestions for applying these principles. The present poster is intended to highlight the prevention science principles articulated by Hage et al. (2007) by describing the activities of the Missouri Prevention Center, a program that uses these principles of prevention science within counseling research to enhance children's mental health
Impurity transport in Alcator C-Mod in the presence of poloidal density variation induced by ion cyclotron resonance heating
Impurity particle transport in an ion cyclotron resonance heated Alcator
C-Mod discharge is studied with local gyrokinetic simulations and a theoretical
model including the effect of poloidal asymmetries and elongation. In spite of
the strong minority temperature anisotropy in the deep core region, the
poloidal asymmetries are found to have a negligible effect on the turbulent
impurity transport due to low magnetic shear in this region, in agreement with
the experimental observations. According to the theoretical model, in outer
core regions poloidal asymmetries may contribute to the reduction of the
impurity peaking, but uncertainties in atomic physics processes prevent
quantitative comparison with experiments.Comment: 32 pages, 12 figure
Evidence and modeling of turbulence bifurcation in L-mode confinement transitions on Alcator C-Mod
© 2020 Author(s). Analysis and modeling of rotation reversal hysteresis experiments show that a single turbulent bifurcation is responsible for the Linear to Saturated Ohmic Confinement (LOC/SOC) transition and concomitant intrinsic rotation reversal on Alcator C-Mod. Plasmas on either side of the reversal exhibit different toroidal rotation profiles and therefore different turbulence characteristics despite the profiles of density and temperature, which are indistinguishable within measurement uncertainty. Elements of this bifurcation are also shown to persist for auxiliary heated L-modes. The deactivation of subdominant (in the linear growth rate and contribution to heat transport) ion temperature gradient and trapped electron mode instabilities is identified as the only possible change in turbulence within a reduced quasilinear transport model across the reversal, which is consistent with the measured profiles and inferred heat and particle fluxes. Experimental constraints on a possible change from strong to weak turbulence, outside the description of the quasilinear model, are also discussed. These results indicate an explanation for the LOC/SOC transition that provides a mechanism for the hysteresis through the dynamics of subdominant modes and changes in their relative populations and does not involve a change in the most linearly unstable ion-scale drift-wave instability
Helping Schools Select and Implement Empirically Supported Practices in Prevention
This poster was presented at the American Psychological Association Conference, Boston, MA, in August 2008.School districts are inundated with innovation. Ongoing developments in academic and social-emotional curriculum, combined with external pressures to improve student outcomes, create challenges for districts to make informed decisions about programs to implement in their schools. In particular, efforts to identify and implement best practices in mental health programming and services are complicated by constantly evolving initiatives, strategies, and delivery systems. Our poster presents a rationale and model for helping school districts select and implement best practices in prevention and mental health promotion programming
The Role of Prevention Science in Promoting Children's Mental Health: A Model for School Psychologists
This poster was presented at the American Psychological Association Conference in Boston, MA, in August 2008.Research has shown that early and focused prevention efforts can greatly reduce the costs, economic, psychological and social, borne by families and societies afflicted by poor mental health. With the help of a model program, the poster highlights school psychologists' involvement in prevention science activities to enhance children's mental health. Specifically, the Missouri Prevention Center exemplifies such a model and it is described in detail
Ultra-high frequency, high Q/volume micromechanical resonators in a planar AlN phononic crystal
Citation: Baboly, M. G., Alaie, S., Reinke, C. M., El-Kady, I., & Leseman, Z. C. (2016). Ultra-high frequency, high Q/volume micromechanical resonators in a planar AlN phononic crystal. Journal of Applied Physics, 120(3), 5. doi:10.1063/1.4958671This paper presents the first design and experimental demonstration of an ultrahigh frequency complete phononic crystal (PnC) bandgap aluminum nitride (AlN)/air structure operating in the GHz range. A complete phononic bandgap of this design is used to efficiently and simultaneously confine elastic vibrations in a resonator. The PnC structure is fabricated by etching a square array of air holes in an AlN slab. The fabricated PnC resonator resonates at 1.117 GHz, which corresponds to an out-of-plane mode. The measured bandgap and resonance frequencies are in very good agreement with the eigen-frequency and frequency-domain finite element analyses. As a result, a quality factor/volume of 7.6 x 10(17)/m(3) for the confined resonance mode was obtained that is the largest value reported for this type of PnC resonator to date. These results are an important step forward in achieving possible applications of PnCs for RF communication and signal processing with smaller dimensions. Published by AIP Publishing
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Metabolomics analysis identifies sex-associated metabotypes of oxidative stress and the autotaxin-lysoPA axis in COPD.
Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease and a leading cause of mortality and morbidity worldwide. The aim of this study was to investigate the sex dependency of circulating metabolic profiles in COPD.Serum from healthy never-smokers (healthy), smokers with normal lung function (smokers), and smokers with COPD (COPD; Global Initiative for Chronic Obstructive Lung Disease stages I-II/A-B) from the Karolinska COSMIC cohort (n=116) was analysed using our nontargeted liquid chromatography-high resolution mass spectrometry metabolomics platform.Pathway analyses revealed that several altered metabolites are involved in oxidative stress. Supervised multivariate modelling showed significant classification of smokers from COPD (p=2.8×10-7). Sex stratification indicated that the separation was driven by females (p=2.4×10-7) relative to males (p=4.0×10-4). Significantly altered metabolites were confirmed quantitatively using targeted metabolomics. Multivariate modelling of targeted metabolomics data confirmed enhanced metabolic dysregulation in females with COPD (p=3.0×10-3) relative to males (p=0.10). The autotaxin products lysoPA (16:0) and lysoPA (18:2) correlated with lung function (forced expiratory volume in 1 s) in males with COPD (r=0.86; p<0.0001), but not females (r=0.44; p=0.15), potentially related to observed dysregulation of the miR-29 family in the lung.These findings highlight the role of oxidative stress in COPD, and suggest that sex-enhanced dysregulation in oxidative stress, and potentially the autotaxin-lysoPA axis, are associated with disease mechanisms and/or prevalence
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