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Realist evaluation

Kathia Sandoval, Yan Ding, Piero Gardinali
Comprehensive characterization of exposure media used in toxicology studies is still an area of significant divergence when evaluating potential oil spill impacts. When preparing exposure media used for toxicology testing, small variations in simple parameters such as mixing energy, oil type and loading can significantly affect the concentration of the oil components to which test organisms are exposed. The key goal of this study was compare and contrast the physical and chemical compositions of oil water mixtures prepared using fresh and weathered Macondo-related oils under different conditions of mixing and in the presence/absence of chemical dispersants...
October 23, 2016: Science of the Total Environment
Cannada Andrew Lewis, Justus Aaron Calvin, Edward F Valeev
We describe the Clustered Low Rank (CLR) framework for block-sparse and block-low-rank tensor representation and computation. The CLR framework exploits the tensor structure revealed by basis clustering; computational savings arise from low-rank compression of tensor blocks and performing block arithmetic in the low-rank form whenever beneficial. The precision is rigorously controlled by 2 parameters, avoiding ad-hoc heuristics, such as domains: one controls the CLR block rank truncation and the other controls screening of small contributions in arithmetic operations on CLR tensors to propagate sparsity through expressions...
October 26, 2016: Journal of Chemical Theory and Computation
Vicki T Taasti, Jørgen B B Petersen, Ludvig P Muren, Jesper Thygesen, David C Hansen
PURPOSE: In this study the authors present a new method for estimation of proton stopping power ratios (SPRs) using dual energy CT (DECT), which is robust toward CT noise. The authors propose a parametrization for SPR based directly on the CT numbers in a DECT image set, whereby the intermediate steps of estimating the relative electron density, ρe, and mean excitation energy, I, are avoided. METHODS: The SPR parametrization proposed in this study is a purely empirical fit based on the theoretical SPR values for a list of 34 reference human tissues...
October 2016: Medical Physics
Xian Teng, Sen Pei, Flaviano Morone, Hernán A Makse
Identifying the most influential spreaders that maximize information flow is a central question in network theory. Recently, a scalable method called "Collective Influence (CI)" has been put forward through collective influence maximization. In contrast to heuristic methods evaluating nodes' significance separately, CI method inspects the collective influence of multiple spreaders. Despite that CI applies to the influence maximization problem in percolation model, it is still important to examine its efficacy in realistic information spreading...
October 26, 2016: Scientific Reports
J L Santiago, R Borge, F Martin, D de la Paz, A Martilli, J Lumbreras, B Sanchez
The distribution of pollutants is spatially heterogeneous within urban streets making difficult to build a realistic concentration map. In this paper, a methodology based on computational fluid dynamic modeling with Reynolds-averaged Navier-Stokes approach is used to compute maps of concentration for a period of several weeks. The methodology is evaluated by comparing simulation results against experimental data from two different campaigns where a large number of passive samplers deployed in an area with heavy vehicular traffic in Madrid (Spain)...
October 22, 2016: Science of the Total Environment
Yu Gu, Yang-Fu Wang, Qiang Li, Zu-Wu Liu
Chinese liquors can be classified according to their flavor types. Accurate identification of Chinese liquor flavors is not always possible through professional sommeliers' subjective assessment. A novel polymer piezoelectric sensor electric nose (e-nose) can be applied to distinguish Chinese liquors because of its excellent ability in imitating human senses by using sensor arrays and pattern recognition systems. The sensor, based on the quartz crystal microbalance (QCM) principle is comprised of a quartz piezoelectric crystal plate sandwiched between two specific gas-sensitive polymer coatings...
October 20, 2016: Sensors
Zakieh Alihemmati, Bahman Vahidi, Nooshin Haghighipour, Mohammad Salehi
It has been found that cells react to mechanical stimuli, while the type and magnitude of these cells are different in various physiological and pathological conditions. These stimuli may affect cell behaviors via mechanotransduction mechanisms. The aim of this study is to evaluate mechanical responses of a mesenchymal stem cell (MSC) to a pressure loading using finite elements method (FEM) to clarify procedures of MSC mechanotransduction. The model is constructed based on an experimental set up in which statics and cyclic compressive loads are implemented on a model constructed from a confocal microscopy 3D image of a stem cell...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Gaurav Kumar Pal, P V Suresh
Collagen and collagen fibers have been widely documented as a potential and competitive biomaterial for medical applications. However, the searches for safe and realistic new collagen sources are still underway. Currently, fishery by-products (scales), a promising collagen source are usually discarded. In the present study, in vitro fibril-forming ability of the extracted fish scale collagen is reported. The aim of the investigation was to evaluate the concomitant comparison of fibril-forming abilities and characteristics of acid and pepsin soluble collagens from the scales of Indian major carp catla (Catla catla) and rohu (Labeo rohita)...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Chen-Hsiang Yeang, Robert A Beckman
BACKGROUND: Current cancer precision medicine strategies match therapies to static consensus molecular properties of an individual's cancer, thus determining the next therapeutic maneuver. These strategies typically maintain a constant treatment while the cancer is not worsening. However, cancers feature complicated sub-clonal structure and dynamic evolution. We have recently shown, in a comprehensive simulation of two non-cross resistant therapies across a broad parameter space representing realistic tumors, that substantial improvement in cure rates and median survival can be obtained utilizing dynamic precision medicine strategies...
October 22, 2016: Biology Direct
Dureid Qazzazie, Mohammad Halhouli, Olena Yurchenko, Gerald Urban
The lack of performance of graphene-based electrocatalysts for oxygen reduction (ORR) is a major concern for fuel cells which can be mastered using nanocomposites. This work is highlighted by the optimization of nitrogen(N)-doped graphene/carbon nanotubes (CNTs) nanocomposite's ORR performance examined by galvanostatic measurements in realistically approached glucose half-cells. Obtained results mark an essential step for the development of nanocarbon-based cathodes, as we specifically evaluate the electrode performance under real fuel cell conditions...
October 21, 2016: Nanotechnology
James Raftery, Steve Hanney, Trish Greenhalgh, Matthew Glover, Amanda Blatch-Jones
BACKGROUND: This report reviews approaches and tools for measuring the impact of research programmes, building on, and extending, a 2007 review. OBJECTIVES: (1) To identify the range of theoretical models and empirical approaches for measuring the impact of health research programmes; (2) to develop a taxonomy of models and approaches; (3) to summarise the evidence on the application and use of these models; and (4) to evaluate the different options for the Health Technology Assessment (HTA) programme...
October 2016: Health Technology Assessment: HTA
Marek Sramko, Dan Wichterle, Josef Kautzner
This study evaluated hemodynamic feasibility and reproducibility of a new method for in vivo simulation of human atrial fibrillation (AF). The method was tested during sinus rhythm in 10 patients undergoing catheter ablation for AF. A simple electronic device was assembled that allowed triggering a cardiac stimulator by predefined series of RR intervals. Irregular RR interval sequences with a mean heart rate of 90/min and 130/min were obtained from ECG recordings of another patients with AF. Simultaneous atrioventricular pacing was delivered by catheters placed inside the coronary sinus and at the His bundle region...
2016: PloS One
Anna B Cope, Catalina Ramirez, Robert F DeVellis, Robert Agans, Victor J Schoenbach, Adaora A Adimora
BACKGROUND: Concurrent sexual partnerships (partnerships that overlap in time) may contribute to higher rates of HIV transmission in African Americans. Attitudes toward a behavior constitute an important component of most models of health-related behavior and behavioral change. We have developed a scale, employing realistic vignettes that appear to reliably measure attitudes about concurrency in young African American adults. METHODS: Vignette-based items to assess attitudes about concurrency were developed following focus groups and cognitive testing of items adapted from existing scales assessing psychosocial constructs surrounding related sexual behaviors...
2016: PloS One
Tina Gupta, Steven M Silverstein, Jessica A Bernard, Brian P Keane, Thomas V Papathomas, Andrea Pelletier-Baldelli, Derek J Dean, Raeana E Newberry, Ivanka Ristanovic, Vijay A Mittal
Patients with psychosis exhibit a reduced susceptibility to depth inversion illusions (DII) in which a physically concave surface is perceived as convex (e.g., the hollow mask illusion). Here, we examined the extent to which lessened susceptibility to DII characterized youth at ultra high risk (UHR) for psychosis. In this study, 44 UHR participants and 29 healthy controls judged the apparent convexity of face-like human masks, two of which were concave and the other convex. One of the concave masks was painted with realistic texture to enhance the illusion; the other was shown without such texture...
2016: NeuroImage: Clinical
Zahra Polat, Erdoğan Bulut, Ahmet Ataş
BACKGROUND: Spoken word recognition and speech perception tests in quiet are being used as a routine in assessment of the benefit which children and adult cochlear implant users receive from their devices. Cochlear implant users generally demonstrate high level performances in these test materials as they are able to achieve high level speech perception ability in quiet situations. Although these test materials provide valuable information regarding Cochlear Implant (CI) users' performances in optimal listening conditions, they do not give realistic information regarding performances in adverse listening conditions, which is the case in the everyday environment...
September 2016: Balkan Medical Journal
Daniela S Tavares, Cláudia B Lopes, Ana L Daniel-da-Silva, Carlos Vale, Tito Trindade, Maria E Pereira
Dithiocarbamate-functionalized magnetite nanoparticles (Fe3O4@SiO2/SiDTC) have been investigated as a convenient and effective sorbent for mercury removal from river, estuarine and sea waters, and their capability to decrease realistic environmental concentrations to the new environmental quality standards was evaluated. The sorption kinetics was well described by the Elovich model and the initial sorption rate was dependent of the sorbent dose. Except for river water sample, the Fe3O4@SiO2/SiDTC particles uptake 99...
October 13, 2016: Water Research
Xiaoqi Li, Yong Chen, Ruosha Li
We consider recurrent events of the same type that occur during alternating restraint and non-restraint time periods. This research is motivated by a study on juvenile recidivism, where the probationers were followed for re-offenses during alternating placement periods and free-time periods. During the placement periods, the probationers were under a restricted environment with direct supervision of the probation officers. During the free-time periods, the probationers were released to home and not under direct supervision...
October 18, 2016: Statistics in Medicine
Jennifer M Hensel, Jay Shaw, Lianne Jeffs, Noah M Ivers, Laura Desveaux, Ashley Cohen, Payal Agarwal, Walter P Wodchis, Joshua Tepper, Darren Larsen, Anita McGahan, Peter Cram, Geetha Mukerji, Muhammad Mamdani, Rebecca Yang, Ivy Wong, Nike Onabajo, Trevor Jamieson, R Sacha Bhatia
BACKGROUND: Mental illness is a substantial and rising contributor to the global burden of disease. Access to and utilization of mental health care, however, is limited by structural barriers such as specialist availability, time, out-of-pocket costs, and attitudinal barriers including stigma. Innovative solutions like virtual care are rapidly entering the health care domain. The advancement and adoption of virtual care for mental health, however, often occurs in the absence of rigorous evaluation and adequate planning for sustainability and spread...
October 18, 2016: BMC Psychiatry
Jill A Awkerman, Becky Hemmer, Alex Almario, Crystal Lilavois, Mace G Barron, Sandy Raimondo
Evaluating long-term contaminant effects on wildlife populations depends on spatial information about habitat quality, heterogeneity in contaminant exposure, and sensitivities and distributions of species integrated into a systems modeling approach. Rarely is this information readily available, making it difficult to determine the applicability of realistic models to quantify population-level risks. To evaluate the trade-offs between data demands and increased specificity of spatially explicit models for population-level risk assessments, we developed a model for a standard toxicity test species, the sheepshead minnow (Cyprinodon variegatus), exposed to oil contamination following the Deepwater Horizon oil spill and compared the output with various levels of model complexity to a standard risk quotient approach...
September 2016: Ecological Applications: a Publication of the Ecological Society of America
Susanne M Van Hooft, Janet M J Been-Dahmen, Erwin Ista, AnneLoes Van Staa, Hennie R Boeije
AIM: To examine how nurse-led interventions that support self-management of outpatients with chronic conditions work and in what contexts they work successfully. BACKGROUND: Self-management could be directed at goals such as quality of life, adherence, or patients' empowerment. Self-management support is an increasingly important task of nurses. Many nurse-led interventions have been developed but it is not clear how these actually help improve patients' self-management capabilities...
October 18, 2016: Journal of Advanced Nursing
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