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https://www.readbyqxmd.com/read/28636276/covariate-selection-with-group-lasso-and-doubly-robust-estimation-of-causal-effects
#1
Brandon Koch, David M Vock, Julian Wolfson
The efficiency of doubly robust estimators of the average causal effect (ACE) of a treatment can be improved by including in the treatment and outcome models only those covariates which are related to both treatment and outcome (i.e., confounders) or related only to the outcome. However, it is often challenging to identify such covariates among the large number that may be measured in a given study. In this article, we propose GLiDeR (Group Lasso and Doubly Robust Estimation), a novel variable selection technique for identifying confounders and predictors of outcome using an adaptive group lasso approach that simultaneously performs coefficient selection, regularization, and estimation across the treatment and outcome models...
June 21, 2017: Biometrics
https://www.readbyqxmd.com/read/28636253/estimation-of-vanadium-water-quality-benchmarks-for-the-protection-of-aquatic-life-with-relevance-to-the-athabasca-oil-sands-region-using-species-sensitivity-distributions
#2
Stephanie Schiffer, Karsten Liber
Elevated vanadium (V) concentrations in oil sands coke, which is produced and stored on the site of some major Athabasca Oil Sands companies, could pose a risk to aquatic ecosystems in northern Alberta, Canada, depending on its future storage and utilization. In the present study, V toxicity was determined in reconstituted Athabasca River water to various freshwater organisms, including 2 midge species (Chironomus dilutus and Chironomus riparius; 4-d and 30- to 40-d exposures) and 2 freshwater fish species (Oncorhynchus mykiss and Pimephales promelas; 4-d and 28-d exposures) to facilitate estimation of water quality benchmarks...
June 21, 2017: Environmental Toxicology and Chemistry
https://www.readbyqxmd.com/read/28636236/assessment-of-silibinin-as-a-potential-antifungal-agent-and-investigation-of-its-mechanism-of-action
#3
Dae Gyu Yun, Dong Gun Lee
Silibinin, which is derived from Silybum marianum (milk thistle), has used as a traditional remedy for liver or biliary disorders and known to have superior antioxidant activity. In addition, silibinin was recently reported to have antifungal effect related to fungal apoptosis against Candida albicans and the interest in the therapeutic effect is increasing. In this study, we found another mode of antifungal action of silibinin and its antibiofilm activity on C. albicans. To investigate influence on fungal plasma membrane, propidium iodide and bis-(1, 3-dibutylbarbituric acid) trimethineoxonol [DiBAC4 (3)] assay were primarily carried out...
June 21, 2017: IUBMB Life
https://www.readbyqxmd.com/read/28636183/ordination-with-any-dissimilarity-measure-a-weighted-euclidean-solution
#4
Michael Greenacre
The classical approach to ordination is to use variants of the Euclidean distance to measure differences between samples (e.g. sites in a community study) based on their observation vectors (e.g. abundance counts for a set of species). Examples are: Euclidean distance on standardized or log-transformed data, on which principal component analysis and redundancy analysis are based; chi-square distance, on which (canonical) correspondence analysis is based; and Hellinger distance, using square roots of relative values in each multivariate vector...
June 21, 2017: Ecology
https://www.readbyqxmd.com/read/28636148/magneto-structural-characterization-of-oxalamide-dihalo-bridged-copper-dimers-intra-and-interdimer-interactions-studied-by-single-crystal-esr-spectroscopy
#5
Dijana Zilic, Debdeep Maity, Mario Cetina, Kresimir Molcanov, Zoran Dzolic, Mirta Herak
The detailed single crystal electron spin resonance (ESR) analysis of oxalamide complexes with halogen-bridged copper dimers, supported by X-ray, magnetic susceptibility and powder ESR studies, is reported. Four complexes with two different ligands were synthesized: [CuLA(μ-X)]₂ and [CuLV(μ-X)]₂, where LA = N-(L-alanine methyl ester)-N'-((2-pyridine-2-yl)methyl)oxalamide and LV=N-(L-valine methyl ester)-N'-((2-pyridine-2-yl)methyl)oxalamide, while X=Cl or Br. X-ray analysis shows that geometry at each copper(II) ion is square pyramidal while two pyramids share one base-to-apex edge with parallel basal planes...
June 21, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28636137/the-experience-of-waiting-for-a-kidney-transplant-a-qualitative-study
#6
Tania Burns, Ritin Fernandez, Moira Stephens
BACKGROUND: In Australia over 1100 people are living on dialysis while waiting for a kidney transplant from a deceased donor. Worldwide there are an estimated 170,000 people who wait an average of three years before an organ becomes available. OBJECTIVE: To provide an understanding of the lived experience of people waiting on dialysis for a kidney transplant from a deceased donor. APPROACH: A qualitative descriptive research design was used...
June 21, 2017: Journal of Renal Care
https://www.readbyqxmd.com/read/28636089/geographic-substructure-in-craniometric-estimates-of-admixture-for-contemporary-american-populations
#7
Bridget F B Algee-Hewitt
OBJECTIVES: This study investigates heterogeneity in craniometrically-derived estimates of admixture in order to reveal population substructure in a sample of Black, White, Hispanic, and Native American individuals from the FDB. It reports evidence of spatial trends in population-specific patterns of admixture and contextualizes its results in terms of demographic diversity in the United States. MATERIALS AND METHODS: The FDB was sampled to capture the population variation within forensic casework, skeletal collections, and the U...
June 21, 2017: American Journal of Physical Anthropology
https://www.readbyqxmd.com/read/28636070/development-of-a-population-based-microsimulation-model-of-body-mass-index
#8
Deirdre Hennessy, Rochelle Garner, William M Flanagan Ron Wall And Claude Nadeau M Flanagan, Ron Wall, Claude Nadeau
BACKGROUND: The increasing prevalence of overweight and obesity has necessitated the development of body mass index (BMI) projection models such as the POpulation HEalth Model (POHEM). This study describes the POHEM-BMI model, a microsimulation tool that can be used to support evidence-based health policy making for obesity reduction. DATA AND METHODS: The National Population Health Survey, the Canadian Community Health Survey (CCHS), and the Canadian Health Measures Survey (CHMS) were used to develop and validate a predictive model of BMI for adults and childhood BMI history...
June 21, 2017: Health Reports
https://www.readbyqxmd.com/read/28635970/expansion-of-the-tibetan-plateau-during-the-neogene
#9
Weitao Wang, Wenjun Zheng, Peizhen Zhang, Qiang Li, Eric Kirby, Daoyang Yuan, Dewen Zheng, Caicai Liu, Zhicai Wang, Huiping Zhang, Jianzhang Pang
The appearance of detritus shed from mountain ranges along the northern margin of the Tibetan Plateau heralds the Cenozoic development of high topography. Current estimates of the age of the basal conglomerate in the Qaidam basin place this event in Paleocene-Eocene. Here we present new magnetostratigraphy and mammalian biostratigraphy that refine the onset of basin fill to ∼25.5 Myr and reveal that sediment accumulated continuously until ∼4.8 Myr. Sediment provenance implies a sustained source in the East Kunlun Shan throughout this time period...
June 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28635963/single-molecule-analysis-of-steroid-receptor-and-cofactor-action-in-living-cells
#10
Ville Paakinaho, Diego M Presman, David A Ball, Thomas A Johnson, R Louis Schiltz, Peter Levitt, Davide Mazza, Tatsuya Morisaki, Tatiana S Karpova, Gordon L Hager
Population-based assays have been employed extensively to investigate the interactions of transcription factors (TFs) with chromatin and are often interpreted in terms of static and sequential binding. However, fluorescence microscopy techniques reveal a more dynamic binding behaviour of TFs in live cells. Here we analyse the strengths and limitations of in vivo single-molecule tracking and performed a comprehensive analysis on the intranuclear dwell times of four steroid receptors and a number of known cofactors...
June 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28635950/genetically-predicted-high-body-mass-index-was-associated-with-increased-gastric-cancer-risk
#11
Yingying Mao, Caiwang Yan, Qun Lu, Meng Zhu, Fei Yu, Cheng Wang, Juncheng Dai, Hongxia Ma, Zhibin Hu, Hongbing Shen, Guangfu Jin
Epidemiological studies have linked body mass index (BMI) with risk of gastrointestinal cancers. However, for gastric cancer, the relationship is more controversial. In particular, it is unclear whether the observed association is due to confounding or bias inherent in conventional observational studies. To investigate whether BMI is causally associated with gastric cancer risk, we applied Mendelian randomization using individual-level data from 2631 gastric cancer cases and 4373 cancer-free controls. We derived a weighted genetic risk score (wGRS) using 37 BMI-associated genetic variants as an instrumental variable...
June 21, 2017: European Journal of Human Genetics: EJHG
https://www.readbyqxmd.com/read/28635678/evaluation-of-classifier-performance-for-multiclass-phenotype-discrimination-in-untargeted-metabolomics
#12
Patrick J Trainor, Andrew P DeFilippis, Shesh N Rai
Statistical classification is a critical component of utilizing metabolomics data for examining the molecular determinants of phenotypes. Despite this, a comprehensive and rigorous evaluation of the accuracy of classification techniques for phenotype discrimination given metabolomics data has not been conducted. We conducted such an evaluation using both simulated and real metabolomics datasets, comparing Partial Least Squares-Discriminant Analysis (PLS-DA), Sparse PLS-DA, Random Forests, Support Vector Machines (SVM), Artificial Neural Network, k-Nearest Neighbors (k-NN), and Naïve Bayes classification techniques for discrimination...
June 21, 2017: Metabolites
https://www.readbyqxmd.com/read/28635640/analysis-of-maneuvering-targets-with-complex-motions-by-two-dimensional-product-modified-lv-s-distribution-for-quadratic-frequency-modulation-signals
#13
Fulong Jing, Shuhong Jiao, Changbo Hou, Weijian Si, Yu Wang
For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM) signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR) and the quadratic chirp rate (QCR) are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed...
June 21, 2017: Sensors
https://www.readbyqxmd.com/read/28635637/a-short-term-biological-indicator-for-long-term-kidney-damage-after-radionuclide-therapy-in-mice
#14
Giovanni Pellegrini, Klaudia Siwowska, Stephanie Haller, Daniel J Antoine, Roger Schibli, Anja Kipar, Cristina Müller
Folate receptor (FR)-targeted radionuclide therapy using folate radioconjugates is of interest due to the expression of the FR in a variety of tumor types. The high renal accumulation of radiofolates presents, however, a risk of radionephropathy. A potential option to address this challenge would be to use radioprotectants, such as amifostine. Methods for early detection of kidney damage that-in this case-cannot be predicted based on dose estimations, would facilitate the development of novel therapies. The aim of this study was, therefore, to assess potentially changing levels of plasma and urine biomarkers and to determine DNA damage at an early stage after radiofolate application...
June 21, 2017: Pharmaceuticals
https://www.readbyqxmd.com/read/28635636/cell-selection-technique-for-millimeter-wave-cellular-systems-with-hybrid-beamforming
#15
Mohammed Saquib Khan, Sung Joon Maeng, Yong Soo Cho
In this paper, a cell selection technique for millimeter-wave (mm-wave) cellular systems with hybrid beamforming is proposed. To select a serving cell, taking into account hybrid beamforming structures in a mm-wave cellular system, the angles of arrival and departure for all candidate cells need to be estimated in the initialization stage, requiring a long processing time. To enable simultaneous multi-beam transmissions in a multi-cell environment, a cell and beam synchronization signal (CBSS) is proposed to carry beam IDs in conjunction with cell IDs...
June 21, 2017: Sensors
https://www.readbyqxmd.com/read/28635625/soil-moisture-content-estimation-based-on-sentinel-1-and-auxiliary-earth-observation-products-a-hydrological-approach
#16
Dimitrios D Alexakis, Filippos-Dimitrios K Mexis, Anthi-Eirini K Vozinaki, Ioannis N Daliakopoulos, Ioannis K Tsanis
A methodology for elaborating multi-temporal Sentinel-1 and Landsat 8 satellite images for estimating topsoil Soil Moisture Content (SMC) to support hydrological simulation studies is proposed. After pre-processing the remote sensing data, backscattering coefficient, Normalized Difference Vegetation Index (NDVI), thermal infrared temperature and incidence angle parameters are assessed for their potential to infer ground measurements of SMC, collected at the top 5 cm. A non-linear approach using Artificial Neural Networks (ANNs) is tested...
June 21, 2017: Sensors
https://www.readbyqxmd.com/read/28635617/the-dosimetric-impact-of-gadolinium-based-contrast-media-in-gbm-brain-patient-plans-for-a-mri-linac
#17
Syed Bilal Ahmad, Moti Raj Paudel, Arman Sarfehnia, Anthony Kim, Geordi Pang, Mark Ruschin, Arjun Sahgal, Brian M Keller
Dosimetric effects of gadolinium based contrast media (Gadovist) were evaluated for the Elekta MRI Linear accelerator (MRL) using the research version of Monaco treatment planning system (TPS). In order to represent a gadolinium uptake it was manually assigned to a phantom as well as to the Gross Tumour Volume (GTV) of 6 Glioblastoma Multiforme (GBM) patients. A preliminary estimate of dose enhancement, due to gadolinium, was performed using the phantom irradiated with a single beam. More complicated assessment was performed for the GBM patients using a 7 field IMRT technique...
June 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28635549/a-missed-primary-care-appointment-correlates-with-a-subsequent-emergency-department-visit-among-children-with-asthma
#18
Colleen Marie McGovern, Margaret Redmond, Kimberly Arcoleo, David R Stukus
OBJECTIVE: Since the Affordable Care Act's implementation, emergency department (ED) visits have increased. Poor asthma control increases the risk of acute exacerbations and preventable ED visits. The Centers for Medicare and Medicaid Services support the reduction of preventable ED visits to reduce healthcare spending. Implementation of interventions to avoid preventable ED visits has become a priority for many healthcare systems yet little data exist examining children's missed asthma management primary care (PC) appointments and subsequent ED visits...
March 2, 2017: Journal of Asthma: Official Journal of the Association for the Care of Asthma
https://www.readbyqxmd.com/read/28635522/dietary-intake-among-opioid-and-alcohol-using-pregnant-women
#19
Shikhar Shrestha, Elizabeth Jimenez, Laura Garrison, Peter Pribis, Dennis W Raisch, Julia M Stephen, Ludmila N Bakhireva
BACKGROUND: Substance abuse in nonpregnant adults has been associated with increased intake in calories and decreased intake of nutrient-dense foods; however, studies examining dietary intake in opioid-using and alcohol-using pregnant women are lacking. OBJECTIVE: The objective of this study was to evaluate dietary intake in opioid-using pregnant women with or without concurrent light-to-moderate alcohol use as compared to abstaining controls. METHODS: This prospective birth cohort included 102 pregnant women classified into four study groups: controls (n = 27), medication-assisted treatment (MAT; n = 26), alcohol (ALC; n = 22), and concurrent use of both substances (MAT + ALC; n = 27)...
February 22, 2017: Substance Use & Misuse
https://www.readbyqxmd.com/read/28635504/applying-rasch-model-analysis-in-the-development-of-the-cantonese-tone-identification-test-cantit
#20
Kathy Y S Lee, Joffee H S Lam, Kit T Y Chan, Charles Andrew van Hasselt, Michael C F Tong
OBJECTIVE: Applying Rasch analysis to evaluate the internal structure of a lexical tone perception test known as the Cantonese Tone Identification Test (CANTIT). DESIGN: A 75-item pool (CANTIT-75) with pictures and sound tracks was developed. Respondents were required to make a four-alternative forced choice on each item. A short version of 30 items (CANTIT-30) was developed based on fit statistics, difficulty estimates, and content evaluation. Internal structure was evaluated by fit statistics and Rasch Factor Analysis (RFA)...
March 1, 2017: International Journal of Audiology
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