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https://www.readbyqxmd.com/read/28213678/unifying-differential-item-functioning-in-factor-analysis-for-categorical-data-under-a-discretization-of-a-normal-variant
#1
Yu-Wei Chang, Nan-Jung Hsu, Rung-Ching Tsai
The multiple-group categorical factor analysis (FA) model and the graded response model (GRM) are commonly used to examine polytomous items for differential item functioning to detect possible measurement bias in educational testing. In this study, the multiple-group categorical factor analysis model (MC-FA) and multiple-group normal-ogive GRM models are unified under the common framework of discretization of a normal variant. We rigorously justify a set of identified parameters and determine possible identifiability constraints necessary to make the parameters just-identified and estimable in the common framework of MC-FA...
February 17, 2017: Psychometrika
https://www.readbyqxmd.com/read/28213373/cost-effectiveness-of-the-2014-u-s-preventive-services-task-force-uspstf-recommendations-for-intensive-behavioral-counseling-interventions-for-adults-with-cardiovascular-risk-factors
#2
Ji Lin, Xiaohui Zhuo, Barbara Bardenheier, Deborah B Rolka, W Edward Gregg, Yuling Hong, Guijing Wang, Ann Albright, Ping Zhang
OBJECTIVE: In 2014, the U.S. Preventive Services Task Force (USPSTF) recommended behavioral counseling interventions for overweight or obese adults with the following known cardiovascular disease risk factors: impaired fasting glucose (IFG), hypertension, dyslipidemia, or metabolic syndrome. We assessed the long-term cost-effectiveness (CE) of implementing the recommended interventions in the U.S. RESEARCH DESIGN AND METHODS: We used a disease progression model to simulate the 25-year CE of the USPSTF recommendation for eligible U...
February 17, 2017: Diabetes Care
https://www.readbyqxmd.com/read/28213189/is-heart-rate-variability-hrv-an-adequate-tool-for-evaluating-human-emotions-a-focus-on-the-use-of-the-international-affective-picture-system-iaps
#3
Kwang-Ho Choi, Junbeom Kim, O Sang Kwon, Min Ji Kim, Yeon Hee Ryu, Ji-Eun Park
Because human emotion varies greatly among individuals and is a qualitative factor, measuring it with any degree of accuracy is very difficult. Heart rate variability (HRV), which is used in evaluations of the autonomic nervous system (ANS), is used to evaluate human emotions. This study examines the validity of HRV as a tool to evaluate emotions using the International Affective Picture System (IAPS). For experimentation, five photos were selected for each of the categories of "happy," "unhappy", and "neutral" from among the images provided by the IAPS...
February 11, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/28213166/influence-of-clamping-stress-and-duration-on-the-trauma-of-liver-tissue-during-surgery-operation
#4
Jin Wang, Qing-Yuan Yu, Wei Li, Bing-Rui Wang, Zhong-Rong Zhou
BACKGROUND: Tissue grasping damage often occurs in minimally invasive surgery, which would increase the postoperative recovery time and the risk of surgical complications. The purpose of this study was to evaluate the relationship between liver tissue trauma and compression stress magnitude and duration during tissue clamping operation. METHODS: The clamping experiments of liver tissues in vivo were conducted by using a universal soft tissue mechanical testing machine under different clamping stress magnitudes and durations...
February 10, 2017: Clinical Biomechanics
https://www.readbyqxmd.com/read/28212418/experimental-evidence-of-formation-of-transparent-exopolymer-particles-tep-and-poc-export-provoked-by-dust-addition-under-current-and-high-pco2-conditions
#5
Justine Louis, Maria Luiza Pedrotti, Frédéric Gazeau, Cécile Guieu
The evolution of organic carbon export to the deep ocean, under anthropogenic forcing such as ocean warming and acidification, needs to be investigated in order to evaluate potential positive or negative feedbacks on atmospheric CO2 concentrations, and therefore on climate. As such, modifications of aggregation processes driven by transparent exopolymer particles (TEP) formation have the potential to affect carbon export. The objectives of this study were to experimentally assess the dynamics of organic matter, after the simulation of a Saharan dust deposition event, through the measurement over one week of TEP abundance and size, and to evaluate the effects of ocean acidification on TEP formation and carbon export following a dust deposition event...
2017: PloS One
https://www.readbyqxmd.com/read/28212401/preload-based-starling-like-control-of-rotary-blood-pumps-an-in-vitro-evaluation
#6
Mahdi Mansouri, Shaun D Gregory, Robert F Salamonsen, Nigel H Lovell, Michael C Stevens, Jo P Pauls, Rini Akmeliawati, Einly Lim
Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs) are used to provide mechanical circulatory support. To address the preload insensitivity of the constant speed controller (CSC) used in conventional LVADs, we developed a preload-based Starling-like controller (SLC). The SLC emulates the Starling law of the heart to maintain mean pump flow ([Formula: see text]) with respect to mean left ventricular end diastolic pressure (PLVEDm) as the feedback signal. The SLC and CSC were compared using a mock circulation loop to assess their capacity to increase cardiac output during mild exercise while avoiding ventricular suction (marked by a negative PLVEDm) and maintaining circulatory stability during blood loss and severe reductions in left ventricular contractility (LVC)...
2017: PloS One
https://www.readbyqxmd.com/read/28212010/assessing-generic-collective-variables-for-determining-reaction-rates-in-metadynamics-simulations
#7
Christopher D Fu, Luiz F L Oliveira, Jim Pfaendtner
A persistent challenge in using the metadynamics method is deciding which degrees of freedom, or collective variables, should be biased because these selections are not obvious and require intuition about the system being studied. There are, however, collective variables, which can be constructed with only basic knowledge about the system studied, that provide an opportunity to alleviate this issue. We simulated two different reacting systems where two types of such collective variables (SPRINT coordinates and the collective variable-driven hyperdynamics method) were biased following the infrequent metadynamics method in order to recover the rates of reactions...
February 17, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28212006/effect-of-sand-bed-depth-and-media-age-on-escherichia-coli-and-turbidity-removal-in-biosand-filters
#8
Julie A Napotnik, Derek Baker, Kristen L Jellison
The main objective of this study was to build several full-scale biosand filters (BSFs) and assess the long-term (9 month) efficacy for particulate and Escherichia coli removal under simulated real-world usage. Four replicates of three different filter designs were built: the traditional concrete BSF, and two scaled-down versions that use a 5-gal or 2-gal bucket, respectively, as the casing material. The smaller sand bed depths in the bucket-sized filters did not impact filter performance with respect to (i) turbidity and E...
February 17, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28211288/imaging-evaluating-of-the-implant-bone-interface-an-in-vitro-radiographic-study
#9
M M Vidor, G S Liedke, M B Vizzotto, Hld da Silveira, P F da Silveira, C W Araujo, Hed da Silveira
OBJECTIVES: To analyze the diagnostic accuracy of conventional and digital radiographic images and the impact of digital filters in evaluating the bone/implant interface. METHODS: Titanium implants were inserted into 74 fresh bovine ribs blocks, 37 fitting tight to the bone walls (simulating the existence of osseointegration), and 37 with a gap of 0.125 mm (simulating a failure in the osseointegration process). Periapical radiographs were taken with conventional film and two phosphor-plate systems (Vista Scan and Express)...
February 17, 2017: Dento Maxillo Facial Radiology
https://www.readbyqxmd.com/read/28211218/the-integration-of-mri-in-radiation-therapy-collaboration-of-radiographers-and-radiation-therapists
#10
Robba Rai, Shivani Kumar, Vikneswary Batumalai, Doaa Elwadia, Lucy Ohanessian, Ewa Juresic, Lynette Cassapi, Shalini K Vinod, Lois Holloway, Paul J Keall, Gary P Liney
The increased utilisation of magnetic resonance imaging (MRI) in radiation therapy (RT) has led to the implementation of MRI simulators for RT treatment planning and influenced the development of MRI-guided treatment systems. There is extensive literature on the advantages of MRI for tumour volume and organ-at-risk delineation compared to computed tomography. MRI provides both anatomical and functional information for RT treatment planning (RTP) as well as quantitative information to assess tumour response for adaptive treatment...
February 16, 2017: Journal of Medical Radiation Sciences
https://www.readbyqxmd.com/read/28211048/the-assessment-of-knowledge-and-learning-in-competence-spaces-the-gain-loss-model-for-dependent-skills
#11
Pasquale Anselmi, Luca Stefanutti, Debora de Chiusole, Egidio Robusto
The gain-loss model (GaLoM) is a formal model for assessing knowledge and learning. In its original formulation, the GaLoM assumes independence among the skills. Such an assumption is not reasonable in several domains, in which some preliminary knowledge is the foundation for other knowledge. This paper presents an extension of the GaLoM to the case in which the skills are not independent, and the dependence relation among them is described by a well-graded competence space. The probability of mastering skill s at the pretest is conditional on the presence of all skills on which s depends...
February 17, 2017: British Journal of Mathematical and Statistical Psychology
https://www.readbyqxmd.com/read/28210896/maximum-availability-and-mineralogical-control-of-chromium-released-from-aod-slag
#12
Junguo Li, Bao Liu, Yanan Zeng, Ziming Wang, Zhiyuan Gao
AOD (argon oxygen decarburization) slag is the by-product in the stainless steel refining process. Chromium existing in AOD slag can leach out and probably poses a serious threat to the environment. To assess the leaching toxicity of chromium released from AOD slag, the temperature-dependent maximum availability leaching test was performed. To determine the controlling mineralogical phases of chromium released from AOD slag, a Visual MINTEQ simulation was established based on Vminteq30 and the FactSage 7.0 database...
March 2017: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/28210755/assessment-of-quinoxyfen-phototransformation-pathways-by-liquid-chromatography-coupled-to-accurate-mass-spectrometry
#13
Priscila Ferri, María Ramil, Isaac Rodríguez, Rosângela Bergamasco, Angélica Marquetotti Salcedo Vieira, Rafael Cela
Quinoxyfen has been recently identified as a priority hazardous substance in the field of the European water policy. In this work, its fate in aqueous samples and solid supports under UV and solar radiation is investigated. Diverse degradation experiments were carried out, at lab scale, using spiked aliquots of different aqueous matrices (ultrapure, treated wastewater and river water) irradiated at different wavelengths (λ = 254 nm, λ = 365 nm and solar light). Half-lives of quinoxyfen (2-26 min) depended on the wavelength and the intensity of radiation whilst the nature of the aqueous matrix did not play an important role in degradation kinetics...
February 16, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28210345/the-dutch-technical-tactical-tennis-test-d4t-for-talent-identification-and-development-psychometric-characteristics
#14
Nikki Kolman, Barbara Huijgen, Tamara Kramer, Marije Elferink-Gemser, Chris Visscher
This study examined the test-retest reliability, validity and feasibility of the newly developed Dutch Technical-Tactical Tennis Test (D4T). This new test is relevant for talent identification and development in tennis. Thirty-two youth male tennis players (age 13.4 ± 0.5) were classified as elite (n = 15) or sub-elite (n = 17) according to their position on the national youth ranking list under 15 years (cut-off rank 50) in the Netherlands. Games, rallies and different tactical situations (i.e. offensive, neutral and defensive) were simulated with a ball machine...
January 1, 2017: Journal of Human Kinetics
https://www.readbyqxmd.com/read/28208832/mitigating-multipath-bias-using-a-dual-polarization-antenna-theoretical-performance-algorithm-design-and-simulation
#15
Lin Xie, Xiaowei Cui, Sihao Zhao, Mingquan Lu
It is well known that multipath effect remains a dominant error source that affects the positioning accuracy of Global Navigation Satellite System (GNSS) receivers. Significant efforts have been made by researchers and receiver manufacturers to mitigate multipath error in the past decades. Recently, a multipath mitigation technique using dual-polarization antennas has become a research hotspot for it provides another degree of freedom to distinguish the line-of-sight (LOS) signal from the LOS and multipath composite signal without extensively increasing the complexity of the receiver...
February 13, 2017: Sensors
https://www.readbyqxmd.com/read/28208231/fast-left-ventricle-tracking-using-localized-anatomical-affine-optical-flow
#16
Sandro Queirós, João L Vilaça, Pedro Morais, Jaime C Fonseca, Jan D'hooge, Daniel Barbosa
In daily clinical cardiology practice, left ventricle (LV) global and regional function assessment is crucial for disease diagnosis, therapy selection and patient follow-up. Currently, this is still a time-consuming task, spending valuable human resources. In this work, a novel fast methodology for automatic LV tracking is proposed based on localized anatomically constrained affine optical flow. This novel method can be combined to previously proposed segmentation frameworks or manually delineated surfaces at an initial frame to obtain fully delineated datasets and, thus, assess both global and regional myocardial function...
February 16, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28208223/conceptualization-of-karstic-aquifer-with-multiple-outlets-using-a-dual-porosity-model
#17
Seiyed Mossa Hosseini, Behzad Ataie-Ashtiani
In this study, two conceptual models, the classic reservoir (CR) model and exchange reservoirs model embedded by dual porosity approach (DPR) are developed for simulation of karst aquifer functioning drained by multiple outlets. The performances of two developed models are demonstrated at a less developed karstic aquifer with three spring outlets located in Zagros Mountain in the south-west of Iran using 22-years of daily data. During the surface recharge, a production function based on water mass balance is implemented for computing the time series of surface recharge to the karst formations...
February 16, 2017: Ground Water
https://www.readbyqxmd.com/read/28208083/biodegradation-testing-of-chemicals-with-high-henry-s-constants-separating-mass-and-effective-concentration-reveals-higher-rate-constants
#18
Heidi Birch, Henrik R Andersen, Mike Comber, Philipp Mayer
During simulation-type biodegradation tests, volatile chemicals will continuously partition between water phase and headspace. This study addressed how (1) this partitioning affects test results and (2) can be accounted for by combining equilibrium partition and dynamic biodegradation models. An aqueous mixture of 9 (semi)volatile chemicals was first generated using passive dosing and then diluted with environmental surface water producing concentrations in the ng/L to μg/L range. After incubation for 2 h to 4 weeks, automated Headspace Solid Phase Microextraction (HS-SPME) was applied directly on the test systems to measure substrate depletion by biodegradation relatively to abiotic controls...
February 3, 2017: Chemosphere
https://www.readbyqxmd.com/read/28207766/climate-change-across-seasons-experiment-ccase-a-new-method-for-simulating-future-climate-in-seasonally-snow-covered-ecosystems
#19
Pamela H Templer, Andrew B Reinmann, Rebecca Sanders-DeMott, Patrick O Sorensen, Stephanie M Juice, Francis Bowles, Laura E Sofen, Jamie L Harrison, Ian Halm, Lindsey Rustad, Mary E Martin, Nicholas Grant
Climate models project an increase in mean annual air temperatures and a reduction in the depth and duration of winter snowpack for many mid and high latitude and high elevation seasonally snow-covered ecosystems over the next century. The combined effects of these changes in climate will lead to warmer soils in the growing season and increased frequency of soil freeze-thaw cycles (FTCs) in winter due to the loss of a continuous, insulating snowpack. Previous experiments have warmed soils or removed snow via shoveling or with shelters to mimic projected declines in the winter snowpack...
2017: PloS One
https://www.readbyqxmd.com/read/28207283/modeling-information-content-via-dirichlet-multinomial-regression-analysis
#20
Alberto Ferrari
Shannon entropy is being increasingly used in biomedical research as an index of complexity and information content in sequences of symbols, e.g. languages, amino acid sequences, DNA methylation patterns and animal vocalizations. Yet, distributional properties of information entropy as a random variable have seldom been the object of study, leading to researchers mainly using linear models or simulation-based analytical approach to assess differences in information content, when entropy is measured repeatedly in different experimental conditions...
February 16, 2017: Multivariate Behavioral Research
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