Sample records for numerous studies implicate

  1. Combinatorial Mathematics: Research into Practice

    ERIC Educational Resources Information Center

    Sriraman, Bharath; English, Lyn D.

    2004-01-01

    Implications and suggestions for using combinatorial mathematics in the classroom through a survey and synthesis of numerous research studies are presented. The implications revolve around five major themes that emerge from analysis of these studies.

  2. Spurious Numerical Solutions Of Differential Equations

    NASA Technical Reports Server (NTRS)

    Lafon, A.; Yee, H. C.

    1995-01-01

    Paper presents detailed study of spurious steady-state numerical solutions of differential equations that contain nonlinear source terms. Main objectives of this study are (1) to investigate how well numerical steady-state solutions of model nonlinear reaction/convection boundary-value problem mimic true steady-state solutions and (2) to relate findings of this investigation to implications for interpretation of numerical results from computational-fluid-dynamics algorithms and computer codes used to simulate reacting flows.

  3. Nonlinearity Domination in Hassellmann Equation as a Reason for Alternative Framework of its Numerical Simulation

    DTIC Science & Technology

    2014-09-30

    nonlinear Schrodinger equation. It is well known that dark solitons are exact solutions of such equation. In the present paper it has been shown that gray...Reason for Alternative Framework of its Numerical Simulation Vladimir Zakharov, Andrei Pushkarev Waves and Solitons LLC 1719 W. Marlette Ave...situation; study of the implications of modulational instability on solitons , rogue waves and air-surface interaction. APPROACH Numerical methods

  4. Genetic Susceptibility to Lymphoma

    PubMed Central

    Skibola, Christine F.; Curry, John D.; Nieters, Alexandra

    2010-01-01

    BACKGROUND Genetic susceptibility studies of lymphoma may serve to identify at risk populations and to elucidate important disease mechanisms. METHODS This review considered all studies published through October 2006 on the contribution of genetic polymorphisms in the risk of lymphoma. RESULTS Numerous studies implicate the role of genetic variants that promote B-cell survival and growth with increased risk of lymphoma. Several reports including a large pooled study by InterLymph, an international consortium of non-Hodgkin lymphoma (NHL) case-control studies, found positive associations between variant alleles in TNF -308G>A and IL10 -3575T>A genes and risk of diffuse large B-cell lymphoma. Four studies reported positive associations between a GSTT1 deletion and risk of Hodgkin and non-Hodgkin lymphoma. Genetic studies of folate-metabolizing genes implicate folate in NHL risk, but further studies that include folate and alcohol assessments are needed. Links between NHL and genes involved in energy regulation and hormone production and metabolism may provide insights into novel mechanisms implicating neuro- and endocrine-immune cross-talk with lymphomagenesis, but will need replication in larger populations. CONCLUSIONS Numerous studies suggest that common genetic variants with low penetrance influence lymphoma risk, though replication studies will be needed to eliminate false positive associations. PMID:17606447

  5. Parental numeric language input to Mandarin Chinese and English speaking preschool children.

    PubMed

    Chang, Alicia; Sandhofer, Catherine M; Adelchanow, Lauren; Rottman, Benjamin

    2011-03-01

    The present study examined the number-specific parental language input to Mandarin- and English-speaking preschool-aged children. Mandarin and English transcripts from the CHILDES database were examined for amount of numeric speech, specific types of numeric speech and syntactic frames in which numeric speech appeared. The results showed that Mandarin-speaking parents talked about number more frequently than English-speaking parents. Further, the ways in which parents talked about number terms in the two languages was more supportive of a cardinal interpretation in Mandarin than in English. We discuss these results in terms of their implications for numerical understanding and later mathematical performance.

  6. Implications of Differential Stress Response Activation Following Non-Frozen Hepatocellular Storage

    PubMed Central

    Corwin, William L.; Baust, John G.; Van Buskirk, Robert G.

    2013-01-01

    Hepatocytes are critical for numerous cell therapies and in vitro investigations. A limiting factor for their use in these applications is the ability to process and preserve them without loss of viability or functionality. Normal rat hepatocytes (NHEPs) and human hepatoma (C3A) cells were stored at either 4°C or 37°C to examine post-processing stress responses. Resveratrol and salubrinal were used during storage to determine how targeted molecular stress pathway modulation would affect cell survival. This study revealed that storage outcome is dependent upon numerous factors including: cell type, storage media, storage length, storage temperature, and chemical modulator. These data implicate a molecular-based stress response that is not universal but is specific to the set of conditions under which cells are stored. Further, these findings allude to the potential for targeted protection or destruction of particular cell types for numerous applications, from diagnostic cell selection to cell-based therapy. Ultimately, this study demonstrates the need for further in-depth molecular investigations into the cellular stress response to bioprocessing and preservation. PMID:24845253

  7. Biological Motion Task Performance Predicts Superior Temporal Sulcus Activity

    ERIC Educational Resources Information Center

    Herrington, John D.; Nymberg, Charlotte; Schultz, Robert T.

    2011-01-01

    Numerous studies implicate superior temporal sulcus (STS) in the perception of human movement. More recent theories hold that STS is also involved in the "understanding" of human movement. However, almost no studies to date have associated STS function with observable variability in action understanding. The present study directly associated STS…

  8. A numerical study of mixing in supersonic combustors with hypermixing injectors

    NASA Technical Reports Server (NTRS)

    Lee, J.

    1993-01-01

    A numerical study was conducted to evaluate the performance of wall mounted fuel-injectors designed for potential Supersonic Combustion Ramjet (SCRAM-jet) engine applications. The focus of this investigation was to numerically simulate existing combustor designs for the purpose of validating the numerical technique and the physical models developed. Three different injector designs of varying complexity were studied to fully understand the computational implications involved in accurate predictions. A dual transverse injection system and two streamwise injector designs were studied. The streamwise injectors were designed with swept ramps to enhance fuel-air mixing and combustion characteristics at supersonic speeds without the large flow blockage and drag contribution of the transverse injection system. For this study, the Mass-Average Navier-Stokes equations and the chemical species continuity equations were solved. The computations were performed using a finite-volume implicit numerical technique and multiple block structured grid system. The interfaces of the multiple block structured grid systems were numerically resolved using the flux-conservative technique. Detailed comparisons between the computations and existing experimental data are presented. These comparisons show that numerical predictions are in agreement with the experimental data. These comparisons also show that a number of turbulence model improvements are needed for accurate combustor flowfield predictions.

  9. A numerical study of mixing in supersonic combustors with hypermixing injectors

    NASA Technical Reports Server (NTRS)

    Lee, J.

    1992-01-01

    A numerical study was conducted to evaluate the performance of wall mounted fuel-injectors designed for potential Supersonic Combustion Ramjet (SCRAM-jet) engine applications. The focus of this investigation was to numerically simulate existing combustor designs for the purpose of validating the numerical technique and the physical models developed. Three different injector designs of varying complexity were studied to fully understand the computational implications involved in accurate predictions. A dual transverse injection system and two streamwise injector designs were studied. The streamwise injectors were designed with swept ramps to enhance fuel-air mixing and combustion characteristics at supersonic speeds without the large flow blockage and drag contribution of the transverse injection system. For this study, the Mass-Averaged Navier-Stokes equations and the chemical species continuity equations were solved. The computations were performed using a finite-volume implicit numerical technique and multiple block structured grid system. The interfaces of the multiple block structured grid systems were numerically resolved using the flux-conservative technique. Detailed comparisons between the computations and existing experimental data are presented. These comparisons show that numerical predictions are in agreement with the experimental data. These comparisons also show that a number of turbulence model improvements are needed for accurate combustor flowfield predictions.

  10. Testing Promotes Eyewitness Accuracy with a Warning: Implications for Retrieval Enhanced Suggestibility

    ERIC Educational Resources Information Center

    Thomas, Ayanna K.; Bulevich, John B.; Chan, Jason C. K.

    2010-01-01

    Numerous studies have demonstrated that repeated retrieval boosts later retention. However, recent research has shown that testing can increase eyewitness susceptibility to misleading post-event information (e.g., Chan, Thomas, & Bulevich, 2009). The present study examines the effects of warning on this counterintuitive finding. In two…

  11. Research Review for the Study of Pacific At-Risk Factors.

    ERIC Educational Resources Information Center

    Kawakami, Alice

    This report provides a brief review of literature on at-risk students and implications for a study being conducted by the Pacific Region Educational Laboratory (PREL). The study aims to identify factors that put students at-risk of failure within the present system of public high schools in the Pacific region. Although numerous studies present a…

  12. The feasibility of desorption on Zeolite-water pair using dry gas

    NASA Astrophysics Data System (ADS)

    Oktariani, E.; Nakashima, K.; Noda, A.; Xue, B.; Tahara, K.; Nakaso, K.; Fukai, J.

    2018-04-01

    The increase in temperature, reduction in partial pressure, reduction in concentration, purging with an inert fluid, and displacement with a more strongly adsorbing species are the basic things that occur in the practical method of desorption. In this study, dry gas at constant temperature and pressure was employed as the aid to reduce the partial pressure in the water desorption on the zeolite 13X. The objective of this study is to confirm the feasibility of desorption using dry gas experimentally and numerically. The implication of heat and mass transfers were numerically investigated to find the most influential. The results of numerical simulation agree with the experimental ones for the distribution of local temperature and average water adsorbed in the packed bed.

  13. The Accuracy of Shock Capturing in Two Spatial Dimensions

    NASA Technical Reports Server (NTRS)

    Carpenter, Mark H.; Casper, Jay H.

    1997-01-01

    An assessment of the accuracy of shock capturing schemes is made for two-dimensional steady flow around a cylindrical projectile. Both a linear fourth-order method and a nonlinear third-order method are used in this study. It is shown, contrary to conventional wisdom, that captured two-dimensional shocks are asymptotically first-order, regardless of the design accuracy of the numerical method. The practical implications of this finding are discussed in the context of the efficacy of high-order numerical methods for discontinuous flows.

  14. Pharmacogenetics of β-Blockers

    PubMed Central

    Shin, Jaekyu; Johnson, Julie A.

    2009-01-01

    β-Blockers are an important cardiovascular drug class, recommended as first-line treatment of numerous diseases such as heart failure, hypertension, and angina, as well as treatment after myocardial infarction. However, responses to a β-blocker are variable among patients. Results of numerous studies now suggest that genetic polymorphisms may contribute to variability in responses to β-blockers. This review summarizes the pharmacogenetic data for β-blockers in patients with various diseases and discusses the potential implications of β-blocker pharmacogenetics in clinical practice. PMID:17542770

  15. The Incest Survivor Syndrome: Implications for Assessment and Treatment.

    ERIC Educational Resources Information Center

    Kirschner, Sam; Kirschner, Diana

    The past decade has witnessed a growing awareness of the prevalence and consequences of childhood sexual abuse. This paper presents findings from numerous studies which indicate that adult survivors of incest suffer from devastating personal and interpersonal difficulties. Recent studies on incest claim that some 20 percent of females and over 16…

  16. On the Factorial Structure of the SAT and Implications for Next-Generation College Readiness Assessments

    ERIC Educational Resources Information Center

    Wiley, Edward W.; Shavelson, Richard J.; Kurpius, Amy A.

    2014-01-01

    The name "SAT" has become synonymous with college admissions testing; it has been dubbed "the gold standard." Numerous studies on its reliability and predictive validity show that the SAT predicts college performance beyond high school grade point average. Surprisingly, studies of the factorial structure of the current version…

  17. A Comparison of the Expertise of University Faculty and Students in American Political Science: Implications for Future Research on High School Civics and Government

    ERIC Educational Resources Information Center

    Budano, Christopher

    2012-01-01

    This study investigated the disciplinary knowledge and nature of expertise among political science experts studying American political science. A comparison group of students who had completed an introductory undergraduate course in American political science also participated in the study. Numerous research studies have found that civics and…

  18. The Quantal Larynx: The Stable Regions of Laryngeal Biomechanics and Implications for Speech Production.

    PubMed

    Moisik, Scott Reid; Gick, Bryan

    2017-03-01

    Recent proposals suggest that (a) the high dimensionality of speech motor control may be reduced via modular neuromuscular organization that takes advantage of intrinsic biomechanical regions of stability and (b) computational modeling provides a means to study whether and how such modularization works. In this study, the focus is on the larynx, a structure that is fundamental to speech production because of its role in phonation and numerous articulatory functions. A 3-dimensional model of the larynx was created using the ArtiSynth platform (http://www.artisynth.org). This model was used to simulate laryngeal articulatory states, including inspiration, glottal fricative, modal prephonation, plain glottal stop, vocal-ventricular stop, and aryepiglotto-epiglottal stop and fricative. Speech-relevant laryngeal biomechanics is rich with "quantal" or highly stable regions within muscle activation space. Quantal laryngeal biomechanics complement a modular view of speech control and have implications for the articulatory-biomechanical grounding of numerous phonetic and phonological phenomena.

  19. A delta-rule model of numerical and non-numerical order processing.

    PubMed

    Verguts, Tom; Van Opstal, Filip

    2014-06-01

    Numerical and non-numerical order processing share empirical characteristics (distance effect and semantic congruity), but there are also important differences (in size effect and end effect). At the same time, models and theories of numerical and non-numerical order processing developed largely separately. Currently, we combine insights from 2 earlier models to integrate them in a common framework. We argue that the same learning principle underlies numerical and non-numerical orders, but that environmental features determine the empirical differences. Implications for current theories on order processing are pointed out. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  20. Numerical Simulation of Vortex Ring Formation in the Presence of Background Flow: Implications for Squid Propulsion

    NASA Astrophysics Data System (ADS)

    Jiang, Houshuo; Grosenbaugh, Mark A.

    2002-11-01

    Numerical simulations are used to study the laminar vortex ring formation in the presence of background flow. The numerical setup includes a round-headed axisymmetric body with a sharp-wedged opening at the posterior end where a column of fluid is pushed out by a piston inside the body. The piston motion is explicitly included into the simulations by using a deforming mesh. The numerical method is verified by simulating the standard vortex ring formation process in quiescent fluid for a wide range of piston stroke to cylinder diameter ratios (Lm/D). The results from these simulations confirm the existence of a universal formation time scale (formation number) found by others from experimental and numerical studies. For the case of vortex ring formation by the piston/cylinder arrangement in a constant background flow (i.e. the background flow is in the direction of the piston motion), the results show that a smaller fraction of the ejected circulation is delivered into the leading vortex ring, thereby decreasing the formation number. The mechanism behind this reduction is believed to be related to the modification of the shear layer profile between the jet flow and the background flow by the external boundary layer on the outer surface of the cylinder. In effect, the vorticity in the jet is cancelled by the opposite signed vorticity in the external boundary layer. Simulations using different end geometries confirm the general nature of the phenomenon. The thrust generated from the jet and the drag forces acting on the body are calculated with and without background flow for different piston programs. The implications of these results for squid propulsion are discussed.

  1. Wellness, Perceived Stress, Mattering, and Marital Satisfaction among Medical Residents and Their Spouses: Implications for Education and Counseling

    ERIC Educational Resources Information Center

    Powers, Anne S.; Myers, Jane E.; Tingle, Lynne R.; Powers, John C.

    2004-01-01

    Numerous studies document that medical education is demanding and stressful, yet few studies have examined the effects of medical training on spouses and medical marriages. Eighty-three individuals (42 couples) living in medical marriages completed questionnaires measuring marital satisfaction, perceived stress, general mattering, and wellness.…

  2. A numerical study on dust devils with implications to global dust budget estimates

    USDA-ARS?s Scientific Manuscript database

    The estimates of the contribution of dust devils (DDs) to the global dust budget have large uncertainties because the dust emission mechanisms in DDs are not yet well understood. In this study, a large-eddy simulation model coupled with a dust scheme is used to investigate DD dust entrainment. DDs a...

  3. An Examination of Class Size Reduction on Teaching and Learning Processes: A Theoretical Perspective

    ERIC Educational Resources Information Center

    Harfitt, Gary James; Tsui, Amy B. M.

    2015-01-01

    The question of how class size impacts on student learning has been debated for some time, not least because it has substantial financial implications for educational policy. The strength of this debate notwithstanding, results from numerous international studies have been inconclusive. The study from which this paper stems sought to conceptualise…

  4. Sleeping Beauty Awakes: Children's Literature and Sex Role Myths.

    ERIC Educational Resources Information Center

    Rose, Karel

    Both males and females are mythologized in children's literature. The internalization of these myths has been found to have far-reaching implications for intellectual achievement and individual functioning in a democracy. Numerous studies have indicated that these sexual myths are destructive to females' self-image. Eleanor Maccoby, in her study…

  5. Wellness Matters

    ERIC Educational Resources Information Center

    Arteaga, Brenda

    2011-01-01

    Creating a healthier school in today's world of budget cuts and seemingly endless to-do lists is not only possible, but it is also imperative. Beyond the health implications, one of the most compelling reasons for creating healthier schools is that wellness serves as a power booster for learning. Numerous studies have documented what educators…

  6. Characteristics Associated with Sleep Duration, Chronotype, and Social Jet Lag in Adolescents

    ERIC Educational Resources Information Center

    Malone, Susan Kohl; Zemel, Babette; Compher, Charlene; Souders, Margaret; Chittams, Jesse; Thompson, Aleda Leis; Lipman, Terri H.

    2016-01-01

    Sleep is a complex behavior with numerous health implications. Identifying sociodemographic and behavioral characteristics of sleep is important for determining those at greatest risk for sleep-related health disparities. In this cross-sectional study, general linear models were used to examine sociodemographic and behavioral characteristics…

  7. Psychoeducational Implications of Sex Chromosome Anomalies

    ERIC Educational Resources Information Center

    Wodrich, David L.; Tarbox, Jennifer

    2008-01-01

    Numerous anomalies involving the sex chromosomes (X or Y) have been documented and their impact on development, learning, and behavior studied. This article reviews three of these disorders, Turner syndrome, Klinefelter syndrome, and Lesch-Nyhan disease. Each of these three is associated with one or more selective impairments or behavioral…

  8. Student Incivility: A Domain Review

    ERIC Educational Resources Information Center

    Burke, Lisa A.; Karl, Katherine; Peluchette, Joy; Evans, W. Randy

    2014-01-01

    A review of the literature was conducted on student incivility in higher education, with an eye toward implications for instructors in business. The incivility construct is defined in the context of numerous associated concepts that have been studied in the higher education literature. Evidence is shared about the prevalence of student incivility…

  9. Evaluation of the expression genes associated with resistance to Aspergillus flavus colonization and aflatoxin production in different maize lines.

    USDA-ARS?s Scientific Manuscript database

    Aflatoxins are carcinogenic toxic compounds produced by Aspergillus flavus during infection of crops including maize (Zea mays L.). Contamination of maize with aflatoxin is exacerbated by late season drought stress. Previous studies have implicated numerous resistance-associated proteins (RAPs) that...

  10. Numerical studies of asymmetric adiabatic accretion flow - The effect of velocity gradients

    NASA Technical Reports Server (NTRS)

    Taam, Ronald E.; Fryxell, B. A.

    1989-01-01

    A numerical study of the time variation of the angular momentum and mass capture rates for a central object accreting from a uniform medium with a velocity gradient transverse to the direction of the mean flow is presented, covering a range of velocity asymmetries and Mach numbers in the incident flow. It is found that the mass accretion rate in a given evolutionary sequence varies in an irregular manner, with the matter accreting onto the central object from either a continuously moving accretion wake or from an accretion disk. The implications of the results from the study of short-term fluctuations observed in the pulse period and luminosity of X-ray pulsars are discussed.

  11. Mixed-Strain Mycobacterium tuberculosis Infections and the Implications for Tuberculosis Treatment and Control

    PubMed Central

    van Helden, Paul D.; Wilson, Douglas; Colijn, Caroline; McLaughlin, Megan M.; Abubakar, Ibrahim; Warren, Robin M.

    2012-01-01

    Summary: Numerous studies have reported that individuals can simultaneously harbor multiple distinct strains of Mycobacterium tuberculosis. To date, there has been limited discussion of the consequences for the individual or the epidemiological importance of mixed infections. Here, we review studies that documented mixed infections, highlight challenges associated with the detection of mixed infections, and discuss possible implications of mixed infections for the diagnosis and treatment of patients and for the community impact of tuberculosis control strategies. We conclude by highlighting questions that should be resolved in order to improve our understanding of the importance of mixed-strain M. tuberculosis infections. PMID:23034327

  12. Cognitive reflection vs. calculation in decision making

    PubMed Central

    Sinayev, Aleksandr; Peters, Ellen

    2015-01-01

    Scores on the three-item Cognitive Reflection Test (CRT) have been linked with dual-system theory and normative decision making (Frederick, 2005). In particular, the CRT is thought to measure monitoring of System 1 intuitions such that, if cognitive reflection is high enough, intuitive errors will be detected and the problem will be solved. However, CRT items also require numeric ability to be answered correctly and it is unclear how much numeric ability vs. cognitive reflection contributes to better decision making. In two studies, CRT responses were used to calculate Cognitive Reflection and numeric ability; a numeracy scale was also administered. Numeric ability, measured on the CRT or the numeracy scale, accounted for the CRT's ability to predict more normative decisions (a subscale of decision-making competence, incentivized measures of impatient and risk-averse choice, and self-reported financial outcomes); Cognitive Reflection contributed no independent predictive power. Results were similar whether the two abilities were modeled (Study 1) or calculated using proportions (Studies 1 and 2). These findings demonstrate numeric ability as a robust predictor of superior decision making across multiple tasks and outcomes. They also indicate that correlations of decision performance with the CRT are insufficient evidence to implicate overriding intuitions in the decision-making biases and outcomes we examined. Numeric ability appears to be the key mechanism instead. PMID:25999877

  13. Cognitive reflection vs. calculation in decision making.

    PubMed

    Sinayev, Aleksandr; Peters, Ellen

    2015-01-01

    Scores on the three-item Cognitive Reflection Test (CRT) have been linked with dual-system theory and normative decision making (Frederick, 2005). In particular, the CRT is thought to measure monitoring of System 1 intuitions such that, if cognitive reflection is high enough, intuitive errors will be detected and the problem will be solved. However, CRT items also require numeric ability to be answered correctly and it is unclear how much numeric ability vs. cognitive reflection contributes to better decision making. In two studies, CRT responses were used to calculate Cognitive Reflection and numeric ability; a numeracy scale was also administered. Numeric ability, measured on the CRT or the numeracy scale, accounted for the CRT's ability to predict more normative decisions (a subscale of decision-making competence, incentivized measures of impatient and risk-averse choice, and self-reported financial outcomes); Cognitive Reflection contributed no independent predictive power. Results were similar whether the two abilities were modeled (Study 1) or calculated using proportions (Studies 1 and 2). These findings demonstrate numeric ability as a robust predictor of superior decision making across multiple tasks and outcomes. They also indicate that correlations of decision performance with the CRT are insufficient evidence to implicate overriding intuitions in the decision-making biases and outcomes we examined. Numeric ability appears to be the key mechanism instead.

  14. Benefits and Risks of Electronic Medical Record (EMR): An Interpretive Analysis of Healthcare Consumers' Perceptions of an Evolving Health Information Systems Technology

    ERIC Educational Resources Information Center

    Thompson, Chester D.

    2013-01-01

    The purpose of this study is to explore healthcare consumers' perceptions of their Electronic Medical Records (EMRs). Although there have been numerous studies regarding EMRs, there have been minimal, if any, research that explores healthcare consumers' awareness of this technology and the social implications that result. As consumers' health…

  15. Numerical calculations of turbulent swirling flow

    NASA Technical Reports Server (NTRS)

    Kubo, I.; Gouldin, F. C.

    1974-01-01

    Description of a numerical technique for solving axisymmetric, incompressible, turbulent swirling flow problems. Isothermal flow calculations are presented for a coaxial flow configuration of special interest. The calculation results are discussed in regard to their implications for the design of gas turbine combustors.

  16. Social and Labour Implications of Flexible Manufacturing Systems.

    ERIC Educational Resources Information Center

    Ebel, Karl-H.

    1985-01-01

    The flexible manufacturing system (FMS), a new way of organizing the production process by means of numerical control machines, robots, and computerized workstations, is described. The author examines some of the implications of FMS and the challenges it poses. (Author/CT)

  17. Flow field analysis of aircraft configurations using a numerical solution to the three-dimensional unified supersonic/hypersonic small disturbance equations, part 1

    NASA Technical Reports Server (NTRS)

    Gunness, R. C., Jr.; Knight, C. J.; Dsylva, E.

    1972-01-01

    The unified small disturbance equations are numerically solved using the well-known Lax-Wendroff finite difference technique. The method allows complete determination of the inviscid flow field and surface properties as long as the flow remains supersonic. Shock waves and other discontinuities are accounted for implicity in the numerical method. This technique was programed for general application to the three-dimensional case. The validity of the method is demonstrated by calculations on cones, axisymmetric bodies, lifting bodies, delta wings, and a conical wing/body combination. Part 1 contains the discussion of problem development and results of the study. Part 2 contains flow charts, subroutine descriptions, and a listing of the computer program.

  18. The Effects of Numerical Magnitude, Size, and Color Saturation on Perceived Interval Duration

    ERIC Educational Resources Information Center

    Alards-Tomalin, Doug; Leboe-McGowan, Jason P.; Shaw, Joshua D. M.; Leboe-McGowan, Launa C.

    2014-01-01

    The relative magnitude (or intensity) of an event can have direct implications on timing estimation. Previous studies have found that greater magnitude stimuli are often reported as longer in duration than lesser magnitudes, including Arabic digits (Xuan, Zhang, He, & Chen, 2007). One explanation for these findings is that different…

  19. Mitigation of oxidative stress and inflammatory signaling by fruit and walnut polyphenols: implications for cognitive aging

    USDA-ARS?s Scientific Manuscript database

    Numerous epidemiological studies have indicated that individuals who consume a diet containing high amounts of fruits and vegetables exhibit fewer age-related diseases such as Alzheimer Disease (AD). A recent report has indicated that individuals who consumed a diet containing 2.5 servings of fruit ...

  20. Perceptions of Value-Congruence with One's Department Chair: Does Match Matter?

    ERIC Educational Resources Information Center

    Virick, Meghna; Strage, Amy

    2016-01-01

    Although studies have examined numerous factors that predict junior faculty success, previous research has paid little attention to the role played by department chairs. Drawing on theory from person-environment fit theory and value congruence, we sought to examine the implication of a match versus mismatch between faculty members and their chairs…

  1. Personal Commitment: A Prerequisite for Women Aspiring to Educational Administration.

    ERIC Educational Resources Information Center

    Moore, Colleen A.

    The decline in the number and status of women in educational administration and the magnitude of their lack of representation in administrative positions is evidenced by numerous studies. To achieve the goal of identifying the components of the problem, solutions suggested by the research, and implications for women who aspire to administrative…

  2. Elementary School Student Mental Health Needs Assessment: Implications for School Counseling Research and Practice.

    ERIC Educational Resources Information Center

    Dykeman, Cass

    This paper reports on the current state of elementary school student mental health needs assessment and makes recommendations for future school counseling research and practice. The review of the theoretical literature on needs assessment examines several studies by numerous researchers. With one exception, all instruments reviewed were generated…

  3. Childhood Sexual Victimization, Educational Attainment, and the Returns to Schooling

    ERIC Educational Resources Information Center

    Robst, John

    2010-01-01

    Numerous studies show that survivors of childhood sexual abuse suffer as adults from depression, post-traumatic stress disorder, alcohol and drug abuse, and other mental illnesses. As such, the effect of experiencing traumatic events during childhood including sexual abuse can have lasting implications. The purpose of this paper is to examine…

  4. The Use of Online Methodologies in Data Collection for Gambling and Gaming Addictions

    ERIC Educational Resources Information Center

    Griffiths, Mark D.

    2010-01-01

    The paper outlines the advantages, disadvantages, and other implications of using the Internet to collect data from gaming addicts. Drawing from experience of numerous addiction studies carried out online by the author, and by reviewing the methodological literature examining online data collection among both gambling addicts and video game…

  5. Genetic and environmental factors affecting early rooting of six Populus genomic groups: implications for tree improvement

    Treesearch

    Ronald S., Jr. Zalesny

    2006-01-01

    Genetic and environmental factors affect the early rooting of Populus planted as unrooted hardwood cuttings. Populus genotypes of six genomic groups were tested in numerous studies for the quantitative genetics of rooting, along with effects of preplanting treatments and soil temperature. Genetics data (e.g. heritabilities,...

  6. Evaluation of the expression of genes associated with resistance to Aspergillus flavus colonization and aflatoxin production in different maize lines

    USDA-ARS?s Scientific Manuscript database

    Aflatoxins are carcinogenic toxic compounds produced by Aspergillus flavus during infection of crops including maize (Zea mays L.). Contamination of maize with aflatoxin is exacerbated by late season drought stress. Previous studies have implicated numerous resistance-associated proteins (RAPs) that...

  7. Doomed to Read in a Second Language: Implications for Learning

    ERIC Educational Resources Information Center

    Miller, Paul; Peleg, Ora

    2010-01-01

    The aim of the study was to elucidate whether and how reliance on a second language impacts the learning of new information under very basic learning conditions. The paradigm used to investigate this issue required individuals to learn a series of associations between numerals and particular letter strings. Participants were two groups of…

  8. Using In-Training Evaluation Report (ITER) Qualitative Comments to Assess Medical Students and Residents: A Systematic Review.

    PubMed

    Hatala, Rose; Sawatsky, Adam P; Dudek, Nancy; Ginsburg, Shiphra; Cook, David A

    2017-06-01

    In-training evaluation reports (ITERs) constitute an integral component of medical student and postgraduate physician trainee (resident) assessment. ITER narrative comments have received less attention than the numeric scores. The authors sought both to determine what validity evidence informs the use of narrative comments from ITERs for assessing medical students and residents and to identify evidence gaps. Reviewers searched for relevant English-language studies in MEDLINE, EMBASE, Scopus, and ERIC (last search June 5, 2015), and in reference lists and author files. They included all original studies that evaluated ITERs for qualitative assessment of medical students and residents. Working in duplicate, they selected articles for inclusion, evaluated quality, and abstracted information on validity evidence using Kane's framework (inferences of scoring, generalization, extrapolation, and implications). Of 777 potential articles, 22 met inclusion criteria. The scoring inference is supported by studies showing that rich narratives are possible, that changing the prompt can stimulate more robust narratives, and that comments vary by context. Generalization is supported by studies showing that narratives reach thematic saturation and that analysts make consistent judgments. Extrapolation is supported by favorable relationships between ITER narratives and numeric scores from ITERs and non-ITER performance measures, and by studies confirming that narratives reflect constructs deemed important in clinical work. Evidence supporting implications is scant. The use of ITER narratives for trainee assessment is generally supported, except that evidence is lacking for implications and decisions. Future research should seek to confirm implicit assumptions and evaluate the impact of decisions.

  9. Young Children Bet On Their Numerical Skills: Metacognition in the Numerical Domain

    PubMed Central

    Vo, Vy A.; Li, Rosa; Kornell, Nate; Pouget, Alexandre; Cantlon, Jessica F.

    2014-01-01

    Metacognition, the ability to assess one’s own knowledge, has been targeted as a critical learning mechanism in mathematics education. Yet, the early childhood origins of metacognition have proven difficult to study. Using a novel nonverbal task and a comprehensive set of metacognitive measures, we provide the strongest evidence to date that young children are metacognitive. We show that children as young as 5 years make metacognitive “bets” on their numerical discriminations in a wagering task. However, contrary to previous reports from adults, children’s metacognition proved to be domain-specific: children’s metacognition in the numerical domain was unrelated to their metacognition in another domain (emotion discrimination). Moreover, children’s metacognitive ability in only the numerical domain predicted their school-based mathematics knowledge. The data provide novel evidence that metacognition is a fundamental, domain-dependent cognitive ability in children. The findings have implications for theories of uncertainty and reveal new avenues for training metacognition in children. PMID:24973137

  10. Using inventory data to determine the impact of drought on tree mortality

    Treesearch

    Greg C. Liknes; Christopher W. Woodall; Charles H. Perry

    2012-01-01

    Drought has been the subject of numerous recent studies that hint at an acceleration of tree mortality due to climate change. In particular, a recent global survey of tree mortality events implicates drought as the cause of quaking aspen mortality in Minnesota, USA in 2007. In this study, data from the Forest Inventory and Analysis program of the USDA Forest Service...

  11. Enhancing Undergraduate Education: Examining Faculty Experiences during Their First Year in a Residential College and Exploring the Implications for Student Affairs Professionals

    ERIC Educational Resources Information Center

    Jessup-Anger, Jody E.; Wawrzynski, Matthew R.; Yao, Christina W.

    2011-01-01

    This qualitative study employed a constructivist, case study approach to explore how faculty made meaning of their experiences in a newly developed residential college at a large, land-grant research university in the Midwest. Findings revealed that faculty focused on determining how to prioritize the numerous opportunities for involvement while…

  12. [Role of myostatin in wasting syndrome associated with chronic diseases].

    PubMed

    Zamora, Elisabet; Galán, Amparo; Simó, Rafael

    2008-11-01

    Muscle wasting is a common process of numerous chronic diseases. Sarcopenia is associated with poor prognosis independently of the outcome of the disease. To date, the mechanisms by which sarcopenia induces these alterations are unknown, but the complexity of muscular metabolism anticipates that many factors can be involved. Myostatin, a new family member of transforming growth factor beta, was initially described from the observation of significant muscular growing in knock out mice for myostatin. Numerous experimental and clinical studies have provided insights in the physiologic knowledge of this protein and its implication in muscle wasting conditions. In recent years different substances have been described that counteract myostatin through numerous physiopathological mecanisms and, therefore, they might be novel therapeutic strategies against the wasting syndrome associated with chronic diseases. In spite of that, more studies are needed to improve the knowledge of all processes involved in muscle wasting in order to prevent its devastating consequences.

  13. Primary care management of patients following bariatric surgery.

    PubMed

    Doolen, Jessica L; Miller, Sally K

    2005-11-01

    To evaluate the nutritional, psychosocial, and other primary care issues faced by nurse practitioners (NPs) and their patients in the long-term management of the increasing population of patients who have had bariatric surgery. An extensive review of the literature provides the foundation for development of assessment and management strategies highlighted in a case study. Management of the patient after bariatric surgery does not end with successful surgical healing. Numerous long-term implications, including significant psychosocial and nutritional issues, require the informed attention of the primary care provider for the rest of the life span. Each year an increasing number of obese patients pursue a surgical solution to obesity, up to an estimated 100,000 in 2004. Numerous long-term health implications are specific to this population. NPs can improve the quality of primary care to these patients by being informed regarding the different procedures and their impact on physiologic phenomena, and the psychosocial issues inherent to extreme weight loss.

  14. Pricing Policies in Academic Libraries.

    ERIC Educational Resources Information Center

    King, Donald W.

    1979-01-01

    Economic considerations of user charges are presented along with economic principles and implications of charging for specific library materials and services. Alternative pricing policies and their implications are described, and, to illustrate the complexity and subtle effects of charging, a numerical example for interlibrary loans is also given.…

  15. Multicultural Teacher Education: Why Teachers Say It Matters in Preparing Them for English Language Learners

    ERIC Educational Resources Information Center

    Kolano, Lan Quach; Dávila, Liv Thorstensson; Lachance, Joan; Coffey, Heather

    2014-01-01

    Numerous studies show that mainstream classroom teachers still remain inadequately prepared to teach diverse students and lack the knowledge base and skills to teach English language learners (ELLs). This has profound implications, particularly in the Southeast, where the rate of school-aged Latino immigrants has grown significantly. Thus, this…

  16. Deficits in Sensory-Specific Devaluation Task Performance Following Genetic Deletions of Cannabinoid (CB1) Receptor

    ERIC Educational Resources Information Center

    Crombag, Hans S.; Johnson, Alexander W.; Zimmer, Anne M.; Zimmer, Andreas; Holland, Peter C.

    2010-01-01

    Cannabinoid CB1 receptor is abundantly expressed throughout the CNS and is implicated in numerous physiological and behavioral functions, including appetite and feeding. In the present study, wild-type and CB1 heterozygous and homozygous knockout mice were tested on an instrumental outcome-selective devaluation task to assess changes in acquired…

  17. Title I Public School Transfer May Potentially Harm Schools' Performance Ratings

    ERIC Educational Resources Information Center

    Freeman Willis, Viola Lorie

    2009-01-01

    The Title I public school transfer option has sparked many debates among educators. Although there are numerous studies that reveal mobility can hurt student performance, the federal No Child Left Behind (NCLB) law urges parents to move their children out of low performing Title I schools. Some school officials may not realize the implications the…

  18. The Complex Relationship between Parental Divorce and the Sense of Control

    ERIC Educational Resources Information Center

    Kim, Joongbaeck; Woo, Hyeyoung

    2011-01-01

    How does parental divorce influence the sense of control in adult offspring? Numerous studies have examined the implications of parental divorce on adult psychological well-being. However, little attention has been paid to the long-term consequences of parental divorce for adult sense of control. Using data from the Survey of Aging, Status, and…

  19. Count on dopamine: influences of COMT polymorphisms on numerical cognition

    PubMed Central

    Júlio-Costa, Annelise; Antunes, Andressa M.; Lopes-Silva, Júlia B.; Moreira, Bárbara C.; Vianna, Gabrielle S.; Wood, Guilherme; Carvalho, Maria R. S.; Haase, Vitor G.

    2013-01-01

    Catechol-O-methyltransferase (COMT) is an enzyme that is particularly important for the metabolism of dopamine. Functional polymorphisms of COMT have been implicated in working memory and numerical cognition. This is an exploratory study that aims at investigating associations between COMT polymorphisms, working memory, and numerical cognition. Elementary school children from 2th to 6th grades were divided into two groups according to their COMT val158met polymorphism [homozygous for valine allele (n = 61) vs. heterozygous plus methionine homozygous children or met+ group (n = 94)]. Both groups were matched for age and intelligence. Working memory was assessed through digit span and Corsi blocks. Symbolic numerical processing was assessed through transcoding and single-digit word problem tasks. Non-symbolic magnitude comparison and estimation tasks were used to assess number sense. Between-group differences were found in symbolic and non-symbolic numerical tasks, but not in working memory tasks. Children in the met+ group showed better performance in all numerical tasks while val homozygous children presented slower development of non-symbolic magnitude representations. These results suggest COMT-related dopaminergic modulation may be related not only to working memory, as found in previous studies, but also to the development of magnitude processing and magnitude representations. PMID:23966969

  20. Lyapunov spectrum of the separated flow around the NACA 0012 airfoil and its dependence on numerical discretization

    NASA Astrophysics Data System (ADS)

    Fernandez, P.; Wang, Q.

    2017-12-01

    We investigate the impact of numerical discretization on the Lyapunov spectrum of separated flow simulations. The two-dimensional chaotic flow around the NACA 0012 airfoil at a low Reynolds number and large angle of attack is considered to that end. Time, space and accuracy-order refinement studies are performed to examine each of these effects separately. Numerical results show that the time discretization has a small impact on the dynamics of the system, whereas the spatial discretization can dramatically change them. Also, the finite-time Lyapunov exponents associated to unstable modes are shown to be positively skewed, and quasi-homoclinic tangencies are observed in the attractor of the system. The implications of these results on flow physics and sensitivity analysis of chaotic flows are discussed.

  1. The relationship between mathematics and language: academic implications for children with specific language impairment and English language learners.

    PubMed

    Alt, Mary; Arizmendi, Genesis D; Beal, Carole R

    2014-07-01

    The present study examined the relationship between mathematics and language to better understand the nature of the deficit and the academic implications associated with specific language impairment (SLI) and academic implications for English language learners (ELLs). School-age children (N = 61; 20 SLI, 20 ELL, 21 native monolingual English [NE]) were assessed using a norm-referenced mathematics instrument and 3 experimental computer-based mathematics games that varied in language demands. Group means were compared with analyses of variance. The ELL group was less accurate than the NE group only when tasks were language heavy. In contrast, the group with SLI was less accurate than the groups with NE and ELLs on language-heavy tasks and some language-light tasks. Specifically, the group with SLI was less accurate on tasks that involved comparing numerical symbols and using visual working memory for patterns. However, there were no group differences between children with SLI and peers without SLI on language-light mathematics tasks that involved visual working memory for numerical symbols. Mathematical difficulties of children who are ELLs appear to be related to the language demands of mathematics tasks. In contrast, children with SLI appear to have difficulty with mathematics tasks because of linguistic as well as nonlinguistic processing constraints.

  2. Determining the value of the fine-structure constant from a current balance: Getting acquainted with some upcoming changes to the SI

    NASA Astrophysics Data System (ADS)

    Davis, Richard S.

    2017-05-01

    The revised International System of Units (SI), expected to be approved late in 2018, has implications for physics pedagogy. The ampere definition, which dates from 1948, will be replaced by a definition that fixes the numerical value of the elementary charge e in coulombs. The kilogram definition, which dates from 1889, will be replaced by a definition that fixes the numerical value of the Planck constant h in joule seconds. Existing SI equations will be completely unaffected. However, there will be a largely negligible, but nevertheless necessary, change to published numerical factors relating SI electrical units to their corresponding units in the Gaussian and other CGS systems of units. The implications of the revised SI for electrical metrology are neatly illustrated by considering the interpretation of results obtained from a current balance in the present SI and in the revised SI.

  3. Quantitative Thermochronology

    NASA Astrophysics Data System (ADS)

    Braun, Jean; van der Beek, Peter; Batt, Geoffrey

    2006-05-01

    Thermochronology, the study of the thermal history of rocks, enables us to quantify the nature and timing of tectonic processes. Quantitative Thermochronology is a robust review of isotopic ages, and presents a range of numerical modeling techniques to allow the physical implications of isotopic age data to be explored. The authors provide analytical, semi-analytical, and numerical solutions to the heat transfer equation in a range of tectonic settings and under varying boundary conditions. They then illustrate their modeling approach built around a large number of case studies. The benefits of different thermochronological techniques are also described. Computer programs on an accompanying website at www.cambridge.org/9780521830577 are introduced through the text and provide a means of solving the heat transport equation in the deforming Earth to predict the ages of rocks and compare them directly to geological and geochronological data. Several short tutorials, with hints and solutions, are also included. Numerous case studies help geologists to interpret age data and relate it to Earth processes Essential background material to aid understanding and using thermochronological data Provides a thorough treatise on numerical modeling of heat transport in the Earth's crust Supported by a website hosting relevant computer programs and colour slides of figures from the book for use in teaching

  4. Determinants of project success

    NASA Technical Reports Server (NTRS)

    Murphy, D. C.; Baker, B. N.; Fisher, D.

    1974-01-01

    The interactions of numerous project characteristics, with particular reference to project performance, were studied. Determinants of success are identified along with the accompanying implications for client organization, parent organization, project organization, and future research. Variables are selected which are found to have the greatest impact on project outcome, and the methodology and analytic techniques to be employed in identification of those variables are discussed.

  5. Vulnerability of reactive skin to electric current perception--a pilot study implicating mast cells and the lymphatic microvasculature.

    PubMed

    Quatresooz, Pascale; Piérard-Franchimont, Claudine; Piérard, Gérald E

    2009-09-01

    Sensitive/reactive skin is regarded as a manifestation of sensory irritation. This susceptibility condition to various exogenous factors suggests the intervention of some neuropeptides and other neurobiological mediators. Mast cells are among the putative implicated cells. The present immunohistochemical and morphometric study was performed on two groups of 36 gender- and age-matched subjects complaining or not from reactive skin as determined by electric current perception. In the mid upper part of the dermis, the numerical density in mast cells and the size of the microvasculature were assessed distinguishing the blood and lymphatic vessels. Globally, the distributions of data were large in reactive skin. This condition was characterized by a prominent increase in both the numerical density in mast cells and the overall size of the lymphatics. By contrast, no difference was found in the size of cutaneous blood vessels. More precisely, it appeared that a subgroup of people with reactive skin exhibited these changes contrasting with some other individuals whose data remained close to the normal range. Mast cells and lymphatics are probably involved in the process of sensory irritation affecting a subgroup of the population.

  6. Evolution and the psychology of intergroup conflict: the male warrior hypothesis.

    PubMed

    McDonald, Melissa M; Navarrete, Carlos David; Van Vugt, Mark

    2012-03-05

    The social science literature contains numerous examples of human tribalism and parochialism-the tendency to categorize individuals on the basis of their group membership, and treat ingroup members benevolently and outgroup members malevolently. We hypothesize that this tribal inclination is an adaptive response to the threat of coalitional aggression and intergroup conflict perpetrated by 'warrior males' in both ancestral and modern human environments. Here, we describe how male coalitional aggression could have affected the social psychologies of men and women differently and present preliminary evidence from experimental social psychological studies testing various predictions from the 'male warrior' hypothesis. Finally, we discuss the theoretical implications of our research for studying intergroup relations both in humans and non-humans and discuss some practical implications.

  7. Task-specific performance effects with different numeric keypad layouts.

    PubMed

    Armand, Jenny T; Redick, Thomas S; Poulsen, Joan R

    2014-07-01

    Two commonly used keypad arrangements are the telephone and calculator layouts. The purpose of this study was to determine if entering different types of numeric information was quicker and more accurate with the telephone or the calculator layout on a computer keyboard numeric keypad. Fifty-seven participants saw a 10-digit numeric stimulus to type with a computer number keypad as quickly and as accurately as possible. Stimuli were presented in either a numerical [1,234,567,890] or phone [(123) 456-7890] format. The results indicated that participants' memory of the layout for the arrangement of keys on a telephone was significantly better than the layout of a calculator. In addition, the results showed that participants were more accurate when entering stimuli using the calculator keypad layout. Critically, participants' response times showed an interaction of stimulus format and keypad layout: participants were specifically slowed when entering numeric stimuli using a telephone keypad layout. Responses made using the middle row of keys were faster and more accurate than responses using the top and bottom row of keys. Implications for keypad design and cell phone usage are discussed. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  8. Event-related potentials dissociate facilitation and interference effects in the numerical Stroop paradigm.

    PubMed

    Szucs, Dénes; Soltész, Fruzsina

    2007-11-05

    In the numerical Stroop paradigm (NSP) participants compare simultaneously presented Arabic digits based on either their numerical or on their physical size dimension. Responses are faster when the numerical and size dimensions are congruent with each other (facilitation), and responses are slower when the numerical and size dimensions are incongruent with each other (interference). We aimed to find out whether facilitation and interference appears during the course of perceptual or response processing. To this end, facilitation and interference effects in the amplitude of event-related brain potentials (ERPs) were examined. The onset of motor preparation was determined by monitoring the lateralized readiness potential. In numerical comparison one facilitation effect was related to perceptual processing at the level of the magnitude representation. A second facilitation effect and interference effects appeared during response processing. In size comparison facilitation and interference appeared exclusively during response processing. In both tasks, ERP interference effects were probably related to contextual analysis and to the conflict monitoring and selection for action activity of the anterior cingulate cortex. The results demonstrate that facilitation and interference effects in the NSP appear during multiple stages of processing, and that they are related to different cognitive processes. Therefore these effects should be clearly separated in studies of the NSP. A model of the processes involved in the NSP is provided and implications for studies of the NSP are drawn.

  9. Cardiac rehabilitation: a comprehensive review

    PubMed Central

    Lear, Scott A; Ignaszewski, Andrew

    2001-01-01

    Cardiac rehabilitation (CR) is a commonly used treatment for men and women with cardiovascular disease. To date, no single study has conclusively demonstrated a comprehensive benefit of CR. Numerous individual studies, however, have demonstrated beneficial effects such as improved risk-factor profile, slower disease progression, decreased morbidity, and decreased mortality. This paper will review the evidence for the use of CR and discuss the implications and limitations of these studies. The safety, relevance to special populations, challenges, and future directions of CR will also be reviewed. PMID:11806801

  10. Implications for Intelligent Tutoring Systems for Research and Practice in Foreign Language Learning, NFLC Occasional Papers.

    ERIC Educational Resources Information Center

    Ginsberg, Ralph B.

    Most of the now commonplace computer-assisted instruction (CAI) uses computers to increase the capacity to perform logical, numerical, and symbolic computations. However, computers are an interactive and potentially intelligent medium. The implications of artificial intelligence (AI) for learning are more radical than those for traditional CAI. AI…

  11. Macroeconomic Analysis of Universal Coverage in the U.S.

    NASA Astrophysics Data System (ADS)

    Feng, Zhigang

    In this paper I employ a dynamic general equilibrium model to study macroeconomic effects and welfare implications of health policies for universal coverage in the U.S. The model is calibrated to the U.S. data. Numerical simulations indicate that adopting universal coverage has several important macroeconomic effects on health expenditures, hours worked, and increases welfare by improving aggregate health status, and removing adverse selection.

  12. A note on nonlinearity bias and dichotomous choice CVM: implications for aggregate benefits estimation

    Treesearch

    R.A. Souter; J. Michael Bowker

    1996-01-01

    It is a generally known statistical fact that the mean of a nonlinear function of a set of random variables is not equivalent to the function evaluated at the means of the variables. However, in dichotomous choice contingent valuation studies, a common practice is to calculate an overall mean (or median) by integrating over offer space (numerically or analytically) an...

  13. Physical oceanography of the US Atlantic and eastern Gulf of Mexico. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Milliman, J.D.; Imamura, E.

    The report provides a summary of the physical oceanography of the U.S. Atlantic and Eastern Gulf of Mexico and its implication to offshore oil and gas exploration and development. Topics covered in the report include: meteorology and air-sea interactions, circulation on the continental shelf, continental slope and rise circulation, Gulf Stream, Loop Current, deep-western boundary current, surface gravity-wave climatology, offshore engineering implications, implications for resource commercialization, and numerical models of pollutant dispersion.

  14. Rigor or mortis: best practices for preclinical research in neuroscience.

    PubMed

    Steward, Oswald; Balice-Gordon, Rita

    2014-11-05

    Numerous recent reports document a lack of reproducibility of preclinical studies, raising concerns about potential lack of rigor. Examples of lack of rigor have been extensively documented and proposals for practices to improve rigor are appearing. Here, we discuss some of the details and implications of previously proposed best practices and consider some new ones, focusing on preclinical studies relevant to human neurological and psychiatric disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Holographic entanglement entropy in imbalanced superconductors

    NASA Astrophysics Data System (ADS)

    Dutta, Arghya; Modak, Sujoy Kumar

    2014-01-01

    We study the behavior of holographic entanglement entropy (HEE) for imbalanced holographic superconductors. We employ a numerical approach to consider the robust case of fully back-reacted gravity system. The hairy black hole solution is found by using our numerical scheme. Then it is used to compute the HEE for the superconducting case. The cases we study show that in presence of a mismatch between two chemical potentials, below the critical temperature, superconducting phase has a lower HEE in comparison to the AdS-Reissner-Nordström black hole phase. Interestingly, the effects of chemical imbalance are different in the contexts of black hole and superconducting phases. For black hole, HEE increases with increasing imbalance parameter while it behaves oppositely for the superconducting phase. The implications of these results are discussed.

  16. Evolution and the psychology of intergroup conflict: the male warrior hypothesis

    PubMed Central

    McDonald, Melissa M.; Navarrete, Carlos David; Van Vugt, Mark

    2012-01-01

    The social science literature contains numerous examples of human tribalism and parochialism—the tendency to categorize individuals on the basis of their group membership, and treat ingroup members benevolently and outgroup members malevolently. We hypothesize that this tribal inclination is an adaptive response to the threat of coalitional aggression and intergroup conflict perpetrated by ‘warrior males’ in both ancestral and modern human environments. Here, we describe how male coalitional aggression could have affected the social psychologies of men and women differently and present preliminary evidence from experimental social psychological studies testing various predictions from the ‘male warrior’ hypothesis. Finally, we discuss the theoretical implications of our research for studying intergroup relations both in humans and non-humans and discuss some practical implications. PMID:22271783

  17. Language and number: a bilingual training study.

    PubMed

    Spelke, E S; Tsivkin, S

    2001-01-01

    Three experiments investigated the role of a specific language in human representations of number. Russian-English bilingual college students were taught new numerical operations (Experiment 1), new arithmetic equations (Experiments 1 and 2), or new geographical or historical facts involving numerical or non-numerical information (Experiment 3). After learning a set of items in each of their two languages, subjects were tested for knowledge of those items, and new items, in both languages. In all the studies, subjects retrieved information about exact numbers more effectively in the language of training, and they solved trained problems more effectively than untrained problems. In contrast, subjects retrieved information about approximate numbers and non-numerical facts with equal efficiency in their two languages, and their training on approximate number facts generalized to new facts of the same type. These findings suggest that a specific, natural language contributes to the representation of large, exact numbers but not to the approximate number representations that humans share with other mammals. Language appears to play a role in learning about exact numbers in a variety of contexts, a finding with implications for practice in bilingual education. The findings prompt more general speculations about the role of language in the development of specifically human cognitive abilities.

  18. Morphology and dynamics of explosive vents

    NASA Astrophysics Data System (ADS)

    Gisler, Galen R.; Galland, Olivier; Haug, Øystein T.

    2014-05-01

    Eruptive processes in nature produce a wide variety of morphologies, including cone sheets, dykes, sills, and pipes. The choice of a particular eruptive style is determined partly by local inhomogeneities, and partly by the gross overall properties of the country rock and the physical properties of the eruptive fluid. In this study we report on experimental and numerical designed to capture a range of morphologies in an eruptive system. Using dimensional analysis we link the experimental and numerical work together and draw implications for field studies. Our experimental work uses silica flour in a Hele-Shaw cell, with air as the eruptive fluid. A phase diagram demonstrates a separation between two distinct morphologies, with vertical structures occurring at high pressure or low depth of fill and diagonal ones at low pressure or high depth of fill. In the numerical work the eruptive fluid is a mixture of basaltic magma, supercritical water, and carbon dioxide, and the ambient material is a fill of basalt with varying material properties. In the numerical work we see three distinct morphologies: vertical pipes are produced at high pressures and softer backgrounds, diagonal pipes at lower pressures and stiffer backgrounds, while horizontal sills are produced in intermediate regimes.

  19. A Longitudinal Study on Predictors of Early Calculation Development among Young Children At-Risk for Learning Difficulties

    PubMed Central

    Peng, Peng; Namkung, Jessica M.; Fuchs, Douglas; Fuchs, Lynn S.; Patton, Samuel; Yen, Loulee; Compton, Donald L.; Zhang, Wenjuan; Miller, Amanda; Hamlett, Carol

    2016-01-01

    The purpose of this study was to explore domain-general cognitive skills, domain-specific academic skills, and demographic characteristics that are associated with calculation development from first through third grade among young children with learning difficulties. Participants were 176 children identified with reading and mathematics difficulties at the beginning of first grade. Data were collected on working memory, language, nonverbal reasoning, processing speed, decoding, numerical competence, incoming calculations, socioeconomic status, and gender at the beginning of first grade and on calculation performance at 4 time points: the beginning of first grade, the end of first grade, the end of second grade, and the end of third grade. Latent growth modelling analysis showed that numerical competence, incoming calculation, processing speed, and decoding skills significantly explained the variance of calculation performance at the beginning of first grade. Numerical competence and processing speed significantly explained the variance of calculation performance at the end of third grade. However, numerical competence was the only significant predictor of calculation development from the beginning of first grade to the end of third grade. Implications of these findings for early calculation instructions among young at-risk children are discussed. PMID:27572520

  20. Confessions of a robot lobotomist

    NASA Technical Reports Server (NTRS)

    Gottshall, R. Marc

    1994-01-01

    Since its inception, numerically controlled (NC) machining methods have been used throughout the aerospace industry to mill, drill, and turn complex shapes by sequentially stepping through motion programs. However, the recent demand for more precision, faster feeds, exotic sensors, and branching execution have existing computer numerical control (CNC) and distributed numerical control (DNC) systems running at maximum controller capacity. Typical disadvantages of current CNC's include fixed memory capacities, limited communication ports, and the use of multiple control languages. The need to tailor CNC's to meet specific applications, whether it be expanded memory, additional communications, or integrated vision, often requires replacing the original controller supplied with the commercial machine tool with a more powerful and capable system. This paper briefly describes the process and equipment requirements for new controllers and their evolutionary implementation in an aerospace environment. The process of controller retrofit with currently available machines is examined, along with several case studies and their computational and architectural implications.

  1. Technology and Jobs: Computer-Aided Design. Numerical-Control Machine-Tool Operators. Office Automation.

    ERIC Educational Resources Information Center

    Stanton, Michael; And Others

    1985-01-01

    Three reports on the effects of high technology on the nature of work include (1) Stanton on applications and implications of computer-aided design for engineers, drafters, and architects; (2) Nardone on the outlook and training of numerical-control machine tool operators; and (3) Austin and Drake on the future of clerical occupations in automated…

  2. The Evolution of Alternative Rural Development Strategies in Ethiopia; Implications for Employment and Income Distribution. African Rural Employment Paper No. 12.

    ERIC Educational Resources Information Center

    Tecle, Tesfai

    As Ethiopia has designed and implemented numerous intensive (geographically concentrated) and minimum-package rural development programs between 1967-75, the purpose of this monograph is to: (1) trace the evolution of these package projects; (2) analyze package performances; and (3) identify the implications for Ethiopian planners and policy…

  3. A Study of the Shaping of the "Emotion and Attitude" Domain in the New English Language Curriculum of China through an EFL Textbook

    ERIC Educational Resources Information Center

    Ma, A.

    2012-01-01

    The English language curriculum (ELC) in China has undergone numerous changes since its modernisation movement in the late 1970s. The recent English language syllabus (2001) marks a new direction by incorporating "emotion and attitude" as one of the ELC's key domains. The implication is that the deep-rooted principle of learning a…

  4. Measures of Residential Energy Consumption and their Relationships to DOE Policy,

    DTIC Science & Technology

    1999-11-01

    on consumer behavior is inconclusive. Du Pont and Lord report that "a large percentage of consumers either ignore or misinterpret the labels (du...residential per capita energy consumption. 2. Implications Consumer behavior with respect to energy efficiency remains poorly understood and the proper...question by studies of consumer behavior . The results are also subject to numerical instability. Descriptive statistics can be helpful in interpreting the

  5. Spurious Solutions Of Nonlinear Differential Equations

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Sweby, P. K.; Griffiths, D. F.

    1992-01-01

    Report utilizes nonlinear-dynamics approach to investigate possible sources of errors and slow convergence and non-convergence of steady-state numerical solutions when using time-dependent approach for problems containing nonlinear source terms. Emphasizes implications for development of algorithms in CFD and computational sciences in general. Main fundamental conclusion of study is that qualitative features of nonlinear differential equations cannot be adequately represented by finite-difference method and vice versa.

  6. Coupling Effects of Unsteady River Discharges and Wave Conditions on Mouth Bar Formation

    NASA Astrophysics Data System (ADS)

    Gao, W.; Shao, D.; Zheng Bing, W.; Yang, W.; Sun, T.; Cui, B.

    2017-12-01

    As a key morphological unit at delta front, the evolution of mouth bar is of critical importance to channel bifurcation and the formation of deltaic distributaries, and therefore have received wide attention, primarily using numerical modelling approaches. Notably, the existing numerical modelling studies were mostly carried out under the assumption that most of the sediments are delivered to the ocean during bankfull discharge stages, so is the most significant deltaic morphological evolution, and hence periods of relatively low river discharge were `safely' neglected, leaving out the effects of unsteadiness of river discharge on the relevant morphodynamic processes altogether. However, the above assumption is worth reviewing in the context of combined fluvial and marine forcing as the relative wave strength has been repeatedly proved to be a critical parameter in estuarine-deltaic morphodynamics. In natural deltas, the period of high river discharge may or may not coincide with the occurrence of maximum wave strength, which further complicates their coupling effects. To assess the coupling effects of unsteady river discharges and wave conditions on mouth bar formation, numerical experiments using Delft3D-SWAN were conducted in this study. A host of combined high-and-low river discharges coupled with varying wave strengths were assumed to mimic the natural variability. Numerical simulation results suggest the existence of three regimes for mouth bar formation, namely, nonexistence of mouth bar (G1), formation of ephemeral mouth bar (G2) and formation of stable mouth bar (G3), which were dictated by the relative wave strength during both onset and reworking stages as well as the reworking time. Implications of the mouth bar formation regimes on delta distributary networks were also discussed. The findings have implications for coastal management at estuaries and deltas such as erosion prevention and mitigation, water and sediment regulation scheme, etc.

  7. The Third World Arms Market in the 1980’s: Implications for U. S. Policy.

    DTIC Science & Technology

    1981-06-02

    transfer of modern armaments has gone beyond6 the bounds of ordinary laisse - faire economics. This study is best remembered for its early recognition of... styles , and 8 relationships" in arms transfers. As in the Adelphi study, arms transfers are tabulated numerically rather than in dollar terms. Country...or sells the services of DOD personnel such as training or management advice. 19 91. ILI ’a.UK E.B. Rex The Third World Arms Market 92. As written

  8. Cognitive correlates of performance in advanced mathematics.

    PubMed

    Wei, Wei; Yuan, Hongbo; Chen, Chuansheng; Zhou, Xinlin

    2012-03-01

    Much research has been devoted to understanding cognitive correlates of elementary mathematics performance, but little such research has been done for advanced mathematics (e.g., modern algebra, statistics, and mathematical logic). To promote mathematical knowledge among college students, it is necessary to understand what factors (including cognitive factors) are important for acquiring advanced mathematics. We recruited 80 undergraduates from four universities in Beijing. The current study investigated the associations between students' performance on a test of advanced mathematics and a battery of 17 cognitive tasks on basic numerical processing, complex numerical processing, spatial abilities, language abilities, and general cognitive processing. The results showed that spatial abilities were significantly correlated with performance in advanced mathematics after controlling for other factors. In addition, certain language abilities (i.e., comprehension of words and sentences) also made unique contributions. In contrast, basic numerical processing and computation were generally not correlated with performance in advanced mathematics. Results suggest that spatial abilities and language comprehension, but not basic numerical processing, may play an important role in advanced mathematics. These results are discussed in terms of their theoretical significance and practical implications. ©2011 The British Psychological Society.

  9. The dynamics of spiral tip adjacent to inhomogeneity in cardiac tissue

    NASA Astrophysics Data System (ADS)

    Zhang, Juan; Tang, Jun; Ma, Jun; Luo, Jin Ming; Yang, Xian Qing

    2018-02-01

    Rotating spiral waves in cardiac tissue are implicated in life threatening cardiac arrhythmias. Experimental and theoretical evidences suggest the inhomogeneities in cardiac tissue play a significant role in the dynamics of spiral waves. Based on a modified 2D cardiac tissue model, the interaction of inhomogeneity on the nearby rigidly rotating spiral wave is numerically studied. The adjacent area of the inhomogeneity is divided to two areas, when the initial rotating center of the spiral tip is located in the two areas, the spiral tip will be attracted and anchor on the inhomogeneity finally, or be repulsed away. The width of the area is significantly dependent on the intensity and size of the inhomogeneity. Our numerical study sheds some light on the mechanism of the interaction of inhomogeneity on the spiral wave in cardiac tissue.

  10. Meso-beta scale numerical simulation studies of terrain-induced jet streak mass/momentum perturbations

    NASA Technical Reports Server (NTRS)

    Lin, Yuh-Lang; Kaplan, Michael L.

    1994-01-01

    An in-depth analysis of observed gravity waves and their relationship to precipitation bands over the Montana mesonetwork during the 1981 CCOPE case study indicates that there were two episodes of coherent internal gravity waves. One of the fundamental unanswered questions from this research, however, concerns the dynamical processes which generated the observed waves, all of which originated from the region encompassing the borders of Montana, Idaho, and Wyoming. While geostrophic adjustment, shearing instability, and terrain where all implicated separately or in concert as possible wave generation mechanisms, the lack of upper-air data within the wave genesis region made it difficult to rigorously define the genesis processes from observations alone. In this report we employ a mesoscale numerical model to help diagnose the intricate early wave generation mechanisms during the first observed wave episode.

  11. Mars Global Surveyor Data Analysis Program. Origins of Small Volcanic Cones: Eruption Mechanisms and Implications for Water on Mars

    NASA Technical Reports Server (NTRS)

    Fagents, Sarah A.; Greeley, Ronald; Thordarson, Thorvaldur

    2002-01-01

    The goal of the proposed work was to determine the origins of small volcanic cones observed in Mars Global Surveyor (MGS) data, and their implications for regolith ice stores and magma volatile contents. For this 1-year study, our approach involved a combination of: Quantitative morphologic analysis and interpretation of Mars Orbiter Camera (MOC) and Mars Orbiter Laser Altimeter (MOLA) data; Numerical modeling of eruption processes responsible for producing the observed features; Fieldwork on terrestrial analogs in Iceland. Following this approach, this study succeeded in furthering our understanding of (i) the spatial and temporal distribution of near-surface water ice, as defined by the distribution and sizes of rootless volcanic cones ("pseudocraters"), and (ii) the properties, eruption conditions, and volatile contents of magmas producing primary vent cones.

  12. Lysine acetyltransferase inhibitors: structure-activity relationships and potential therapeutic implications.

    PubMed

    Fiorentino, Francesco; Mai, Antonello; Rotili, Dante

    2018-05-01

    Lysine acetylation is a post-translational modification of both histone and nonhistone proteins that is catalyzed by lysine acetyltransferases and plays a key role in numerous biological contexts. The dysregulation of this enzyme activity is implicated in many human pathologies such as cancer, neurological and inflammatory disorders. Many lysine acetyltransferase inhibitors (KATi) have been developed so far, but there is still the need for new, more potent, metabolically stable and selective KATi as chemical tools for studying KAT biology and/or as potential therapeutic agents. This review will examine the features of KAT enzymes and related diseases, with particular emphasis on KATi (bisubstrate analogs, natural compounds and synthetic derivatives), analyzing their mechanism of action, structure-activity relationships, pharmacokinetic/pharmacodynamic properties and potential future applications.

  13. Adolescent Pregnancy: An Interdisciplinary Problem

    ERIC Educational Resources Information Center

    Duxbury, Mitzi

    1976-01-01

    Deals with the scope of adolescent pregnancy both numerically and in human terms, pregnancy resolution, long term effects on the mother, associated medical factors, and implications for educational personnel. (Author/RK)

  14. Firefly Algorithm, Lévy Flights and Global Optimization

    NASA Astrophysics Data System (ADS)

    Yang, Xin-She

    Nature-inspired algorithms such as Particle Swarm Optimization and Firefly Algorithm are among the most powerful algorithms for optimization. In this paper, we intend to formulate a new metaheuristic algorithm by combining Lévy flights with the search strategy via the Firefly Algorithm. Numerical studies and results suggest that the proposed Lévy-flight firefly algorithm is superior to existing metaheuristic algorithms. Finally implications for further research and wider applications will be discussed.

  15. Engineered BDNF producing cells as a potential treatment for neurologic disease

    PubMed Central

    Deng, Peter; Anderson, Johnathon D.; Yu, Abigail S.; Annett, Geralyn; Fink, Kyle D.; Nolta, Jan A.

    2018-01-01

    Introduction Brain-derived neurotrophic factor (BDNF) has been implicated in wide range of neurological diseases and injury. This neurotrophic factor is vital for neuronal health, survival, and synaptic connectivity. Many therapies focus on the restoration or enhancement of BDNF following injury or disease progression. Areas covered The present review will focus on the mechanisms in which BDNF exerts its beneficial functioning, current BDNF therapies, issues and potential solutions for delivery of neurotrophic factors to the central nervous system, and other disease indications that may benefit from overexpression or restoration of BDNF. Expert opinion Due to the role of BDNF in neuronal development, maturation, and health, BDNF is implicated in numerous neurological diseases making it a prime therapeutic agent. Numerous studies have shown the therapeutic potential of BDNF in a number of neurodegenerative disease models and in acute CNS injury, however clinical translation has fallen short due to issues in delivering this molecule. The use of MSC as a delivery platform for BDNF holds great promise for clinical advancement of neurotrophic factor restoration. The ease with which MSC can be engineered opens the door to the possibility of using this cell-based delivery system to advance a BDNF therapy to the clinic. PMID:27159050

  16. A longitudinal study on predictors of early calculation development among young children at risk for learning difficulties.

    PubMed

    Peng, Peng; Namkung, Jessica M; Fuchs, Douglas; Fuchs, Lynn S; Patton, Samuel; Yen, Loulee; Compton, Donald L; Zhang, Wenjuan; Miller, Amanda; Hamlett, Carol

    2016-12-01

    The purpose of this study was to explore domain-general cognitive skills, domain-specific academic skills, and demographic characteristics that are associated with calculation development from first grade to third grade among young children with learning difficulties. Participants were 176 children identified with reading and mathematics difficulties at the beginning of first grade. Data were collected on working memory, language, nonverbal reasoning, processing speed, decoding, numerical competence, incoming calculations, socioeconomic status, and gender at the beginning of first grade and on calculation performance at four time points: the beginning of first grade, the end of first grade, the end of second grade, and the end of third grade. Latent growth modeling analysis showed that numerical competence, incoming calculation, processing speed, and decoding skills significantly explained the variance in calculation performance at the beginning of first grade. Numerical competence and processing speed significantly explained the variance in calculation performance at the end of third grade. However, numerical competence was the only significant predictor of calculation development from the beginning of first grade to the end of third grade. Implications of these findings for early calculation instructions among young at-risk children are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. China-Pakistan Economic Corridor.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boyce, Tucker

    International trade and related economic activities in Central and South Asia are increasing as developing economies, particularly India and Pakistan, grow. China continues to emerge as a major regional and global power and has embarked upon numerous regional economic and political initiatives . A major development is the China - Pakistan Economic Corridor (CPEC), a host of infrastructure and trade projects worth over 40 billion American dollars . This report analyzes CPEC a nd its potential regional effects, including the trade security implications of the port and land infrastructure developments . As trade increase s in the reg ion andmore » the major CPEC infrastructure projects are completed, there will be numerous implications on trade security and geopolitics within South Asia. CPEC projects uniquely intersect numerous regional situations, including territorial disputes in Kashmir, the Afghanistan/Pakistan border, and Chinese foreign policy a mbitions. A nuanced understanding of these effects can influence future policy adjustments in this region . The views expressed in this report are those of the author and do not necessarily reflect the position of Sandia National Laboratories or the author's current and past institutions.« less

  18. Smokers' knowledge and understanding of advertised tar numbers: health policy implications.

    PubMed

    Cohen, J B

    1996-01-01

    This article examines health policy implications of providing smokers with numerical tar yield information in cigarette advertising. Results of a national probability telephone survey regarding smokers' knowledge and understanding of numerical tar yields and deliveries are reported. Few smokers knew the tar level of their own cigarettes (the exception being smokers of 1- to 5-mg tar cigarettes), and a majority could not correctly judge the relative tar levels of cigarettes. Smokers were unsure whether switching to lower-tar cigarettes would reduce their personal health risks. Many smokers relied on absolute numbers in making trade-offs between number of cigarettes smoked and their tar levels, thus confusion machine-rated tar-yields with actual amounts ingested. The wisdom of the present method of providing tar and nicotine numbers in ads and recommendations for modifying the test protocol are now under discussion. This research indicates that these tar numbers and their implications are poorly understood. The paper recommends revisions in tar ratings to make them more useful and a required statement on cigarette packages to more explicitly relate tar levels to major health risks.

  19. Smokers' knowledge and understanding of advertised tar numbers: health policy implications.

    PubMed Central

    Cohen, J B

    1996-01-01

    OBJECTIVES. This article examines health policy implications of providing smokers with numerical tar yield information in cigarette advertising. METHODS. Results of a national probability telephone survey regarding smokers' knowledge and understanding of numerical tar yields and deliveries are reported. RESULTS. Few smokers knew the tar level of their own cigarettes (the exception being smokers of 1- to 5-mg tar cigarettes), and a majority could not correctly judge the relative tar levels of cigarettes. Smokers were unsure whether switching to lower-tar cigarettes would reduce their personal health risks. Many smokers relied on absolute numbers in making trade-offs between number of cigarettes smoked and their tar levels, thus confusion machine-rated tar-yields with actual amounts ingested. CONCLUSIONS. The wisdom of the present method of providing tar and nicotine numbers in ads and recommendations for modifying the test protocol are now under discussion. This research indicates that these tar numbers and their implications are poorly understood. The paper recommends revisions in tar ratings to make them more useful and a required statement on cigarette packages to more explicitly relate tar levels to major health risks. PMID:8561236

  20. Dynamical approach study of spurious steady-state numerical solutions of nonlinear differential equations. Part 1: The ODE connection and its implications for algorithm development in computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Sweby, P. K.; Griffiths, D. F.

    1990-01-01

    Spurious stable as well as unstable steady state numerical solutions, spurious asymptotic numerical solutions of higher period, and even stable chaotic behavior can occur when finite difference methods are used to solve nonlinear differential equations (DE) numerically. The occurrence of spurious asymptotes is independent of whether the DE possesses a unique steady state or has additional periodic solutions and/or exhibits chaotic phenomena. The form of the nonlinear DEs and the type of numerical schemes are the determining factor. In addition, the occurrence of spurious steady states is not restricted to the time steps that are beyond the linearized stability limit of the scheme. In many instances, it can occur below the linearized stability limit. Therefore, it is essential for practitioners in computational sciences to be knowledgeable about the dynamical behavior of finite difference methods for nonlinear scalar DEs before the actual application of these methods to practical computations. It is also important to change the traditional way of thinking and practices when dealing with genuinely nonlinear problems. In the past, spurious asymptotes were observed in numerical computations but tended to be ignored because they all were assumed to lie beyond the linearized stability limits of the time step parameter delta t. As can be seen from the study, bifurcations to and from spurious asymptotic solutions and transitions to computational instability not only are highly scheme dependent and problem dependent, but also initial data and boundary condition dependent, and not limited to time steps that are beyond the linearized stability limit.

  1. Numerical Prediction of Chevron Nozzle Noise Reduction using Wind-MGBK Methodology

    NASA Technical Reports Server (NTRS)

    Engblom, W.A.; Bridges, J.; Khavarant, A.

    2005-01-01

    Numerical predictions for single-stream chevron nozzle flow performance and farfield noise production are presented. Reynolds Averaged Navier Stokes (RANS) solutions, produced via the WIND flow solver, are provided as input to the MGBK code for prediction of farfield noise distributions. This methodology is applied to a set of sensitivity cases involving varying degrees of chevron inward bend angle relative to the core flow, for both cold and hot exhaust conditions. The sensitivity study results illustrate the effect of increased chevron bend angle and exhaust temperature on enhancement of fine-scale mixing, initiation of core breakdown, nozzle performance, and noise reduction. Direct comparisons with experimental data, including stagnation pressure and temperature rake data, PIV turbulent kinetic energy fields, and 90 degree observer farfield microphone data are provided. Although some deficiencies in the numerical predictions are evident, the correct farfield noise spectra trends are captured by the WIND-MGBK method, including the noise reduction benefit of chevrons. Implications of these results to future chevron design efforts are addressed.

  2. Using Visual Aids to Improve Communication of Risks about Health: A Review

    PubMed Central

    Garcia-Retamero, Rocio; Okan, Yasmina; Cokely, Edward T.

    2012-01-01

    Recent research has shown that patients frequently experience difficulties understanding health-relevant numerical concepts. A prominent example is denominator neglect, or the tendency to pay too much attention to numerators in ratios (e.g., number of treated patients who died) with insufficient attention to denominators (e.g., overall number of treated patients). Denominator neglect can lead to inaccurate assessments of treatment risk reduction and thus can have important consequences for decisions about health. Here, we reviewed a series of studies investigating (1) different factors that can influence patients' susceptibility to denominator neglect in medical decision making—including numerical or language-related abilities; (2) the extent to which denominator neglect can be attenuated by using visual aids; and (3) a factor that moderates the effectiveness of such aids (i.e., graph literacy). The review spans probabilistic national U.S. and German samples, as well as immigrant (i.e., Polish people living in the United Kingdom) and undergraduate samples in Spain. Theoretical and prescriptive implications are discussed. PMID:22629146

  3. Diverse structures, functions and uses of FK506 binding proteins.

    PubMed

    Bonner, Julia Maeve; Boulianne, Gabrielle L

    2017-10-01

    FK506 (Tacrolimus), isolated from Streptomyces tsukubaenis is a powerful immunosuppressant shown to inhibit T cell activation. FK506 mediated immunosuppression requires the formation of a complex between FK506, a FK506 binding protein (FKBP) and calcineurin. Numerous FKBPs have been identified in a wide range of species, from single celled organisms to humans. FKBPs show peptidylprolyl cis/trans isomerase (PPIase) activity and have been shown to affect a wide range of cellular processes including protein folding, receptor signaling and apoptosis. FKBPs also affect numerous biological functions in addition to immunosuppression including regulation of cardiac function, neuronal function and development and have been implicated in several diseases including cardiac disease, cancer and neurodegenerative diseases such as Alzheimer's disease. More recently, FKBPs have proven useful as molecular tools for studying protein interactions, localization and functions. This review provides an overview of the current state of knowledge of FKBPs and their numerous biological functions and uses. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Using visual aids to improve communication of risks about health: a review.

    PubMed

    Garcia-Retamero, Rocio; Okan, Yasmina; Cokely, Edward T

    2012-01-01

    Recent research has shown that patients frequently experience difficulties understanding health-relevant numerical concepts. A prominent example is denominator neglect, or the tendency to pay too much attention to numerators in ratios (e.g., number of treated patients who died) with insufficient attention to denominators (e.g., overall number of treated patients). Denominator neglect can lead to inaccurate assessments of treatment risk reduction and thus can have important consequences for decisions about health. Here, we reviewed a series of studies investigating (1) different factors that can influence patients' susceptibility to denominator neglect in medical decision making--including numerical or language-related abilities; (2) the extent to which denominator neglect can be attenuated by using visual aids; and (3) a factor that moderates the effectiveness of such aids (i.e., graph literacy). The review spans probabilistic national U.S. and German samples, as well as immigrant (i.e., Polish people living in the United Kingdom) and undergraduate samples in Spain. Theoretical and prescriptive implications are discussed.

  5. The underlying number-space mapping among kindergarteners and its relation with early numerical abilities.

    PubMed

    Chan, Winnie Wai Lan; Wong, Terry Tin-Yau

    2016-08-01

    People map numbers onto space. The well-replicated SNARC (spatial-numerical association of response codes) effect indicates that people have a left-sided bias when responding to small numbers and a right-sided bias when responding to large numbers. This study examined whether such spatial codes were tagged to the ordinal or magnitude information of numbers among kindergarteners and whether it was related to early numerical abilities. Based on the traditional magnitude judgment task, we developed two variant tasks-namely the month judgment task and dot judgment task-to elicit ordinal and magnitude processing of numbers, respectively. Results showed that kindergarteners oriented small numbers toward the left side and large numbers toward the right side when processing the ordinal information of numbers in the month judgment task but not when processing the magnitude information in the number judgment task and dot judgment task, suggesting that the left-to-right spatial bias was probably tagged to the ordinal but not magnitude property of numbers. Moreover, the strength of the SNARC effect was not related to early numerical abilities. These findings have important implications for the early spatial representation of numbers and its role in numerical performance among kindergarteners. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Investigation of detonation velocity in heterogeneous explosive system using the reactive Burgers' analog

    NASA Astrophysics Data System (ADS)

    Di Labbio, G.; Kiyanda, C. B.; Mi, X.; Higgins, A. J.; Nikiforakis, N.; Ng, H. D.

    2016-06-01

    In this study, the applicability of the Chapman-Jouguet (CJ) criterion is tested numerically for heterogeneous explosive media using a simple detonation analog. The analog system consists of a reactive Burgers' equation coupled with an Arrhenius type reaction wave, and the heterogeneity of the explosive media is mimicked using a discrete energy source approach. The governing equation is solved using a second order, finite-volume approach and the average propagation velocity of the discrete detonation is determined by tracking the leading shock front. Consistent with previous studies, the averaged velocity of the leading shock front from the unsteady numerical simulations is also found to be in good agreement with the velocity of a CJ detonation in a uniform medium wherein the energy source is spatially homogenized. These simulations have thus implications for whether the CJ criterion is valid to predict the detonation velocity in heterogeneous explosive media.

  7. Constraining the relative importance of raindrop- and flow-driven sediment transport mechanisms in postwildfire environments and implications for recovery time scales

    USGS Publications Warehouse

    McGuire, Luke; Kean, Jason W.; Staley, Dennis M.; Rengers, Francis K.; Wasklewicz, Thad A.

    2016-01-01

    Mountain watersheds recently burned by wildfire often experience greater amounts of runoff and increased rates of sediment transport relative to similar unburned areas. Given the sedimentation and debris flow threats caused by increases in erosion, more work is needed to better understand the physical mechanisms responsible for the observed increase in sediment transport in burned environments and the time scale over which a heightened geomorphic response can be expected. In this study, we quantified the relative importance of different hillslope erosion mechanisms during two postwildfire rainstorms at a drainage basin in Southern California by combining terrestrial laser scanner-derived maps of topographic change, field measurements, and numerical modeling of overland flow and sediment transport. Numerous debris flows were initiated by runoff at our study area during a long-duration storm of relatively modest intensity. Despite the presence of a well-developed rill network, numerical model results suggest that the majority of eroded hillslope sediment during this long-duration rainstorm was transported by raindrop-induced sediment transport processes, highlighting the importance of raindrop-driven processes in supplying channels with potential debris flow material. We also used the numerical model to explore relationships between postwildfire storm characteristics, vegetation cover, soil infiltration capacity, and the total volume of eroded sediment from a synthetic hillslope for different end-member erosion regimes. This study adds to our understanding of sediment transport in steep, postwildfire landscapes and shows how data from field monitoring can be combined with numerical modeling of sediment transport to isolate the processes leading to increased erosion in burned areas.

  8. [DNA structure from A to Z--biological implications of structural diversity of DNA].

    PubMed

    Bukowiecka-Matusiak, Małgorzata; Woźniak, Lucyna A

    2006-01-01

    Deoxyribonucleic acid (DNA) is a biopolymer of nucleotides, usually adopting a double-stranded helical form in cells, with complementary base pairing holding the two strands together. The most stable is B-DNA conformation, although numerous other double helical structures can occur under specific conditions (A-DNA, Z-DNA, P-DNA). The existence of multiple-stranded (triplex, tetraplex) forms in vivo and their biological function in cells are subject of intensive studies.

  9. Genome-wide association implicates numerous genes and pleiotropy underlying ecological trait variation in natural populations of Populus trichocarpa

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McKown, Athena; Klapste, Jaroslav; Guy, Robert

    2014-01-01

    To uncover the genetic basis of phenotypic trait variation, we used 448 unrelated wild accessions of black cottonwood (Populus trichocarpa Torr. & Gray) from natural populations throughout western North America. Extensive information from large-scale trait phenotyping (with spatial and temporal replications within a common garden) and genotyping (with a 34K Populus SNP array) of all accessions were used for gene discovery in a genome-wide association study (GWAS).

  10. Dynamical conductivity at the dirty superconductor-metal quantum phase transition.

    PubMed

    Del Maestro, Adrian; Rosenow, Bernd; Hoyos, José A; Vojta, Thomas

    2010-10-01

    We study the transport properties of ultrathin disordered nanowires in the neighborhood of the superconductor-metal quantum phase transition. To this end we combine numerical calculations with analytical strong-disorder renormalization group results. The quantum critical conductivity at zero temperature diverges logarithmically as a function of frequency. In the metallic phase, it obeys activated scaling associated with an infinite-randomness quantum critical point. We extend the scaling theory to higher dimensions and discuss implications for experiments.

  11. [Knowing without remembering: the contribution of developmental amnesia].

    PubMed

    Lebrun-Givois, C; Guillery-Girard, B; Thomas-Anterion, C; Laurent, B

    2008-05-01

    The organization of episodic and semantic memory is currently debated, and especially the rule of the hippocampus in the functioning of these two systems. Since theories derived from the observation of the famous patient HM, that highlighted the involvement of this structure in these two systems, numerous studies questioned the implication of the hippocampus in learning a new semantic knowledge. Among these studies, we found Vargha-Kadem's cases of developmental amnesia. In spite of their clear hippocampal atrophy and a massive impairment of episodic memory, these children were able to acquire de novo new semantic knowledge. In the present paper, we describe a new case of developmental amnesia characteristic of this syndrome. In conclusion, the whole published data question the implication of the hippocampus in every semantic learning and suggest the existence of a neocortical network, slower and that needs more exposures to semantic stimuli than the hippocampal one, which can supply a massive hippocampal impairment.

  12. Blood and Treasure: The U.S. Debt and Its Implications for National Defense and Security

    DTIC Science & Technology

    2012-12-01

    Reserve Board, “Major Foreign Holders of Treasury Securities ,” 15 May 2012. http://www.treasury.gov/resource-center/ data -chart- center/tic/Documents...Coupled with numerous cyber -attacks and theft of intelligence, China could be performing dry runs and gaining intelligence on every occasion for the...THE U.S. DEBT AND ITS IMPLICATIONS FOR NATIONAL DEFENSE AND SECURITY by Nicholas C. Malokofsky December 2012 Thesis Advisor: Carolyn

  13. A review of direct numerical simulations of astrophysical detonations and their implications

    DOE PAGES

    Parete-Koon, Suzanne T.; Smith, Christopher R.; Papatheodore, Thomas L.; ...

    2013-04-11

    Multi-dimensional direct numerical simulations (DNS) of astrophysical detonations in degenerate matter have revealed that the nuclear burning is typically characterized by cellular structure caused by transverse instabilities in the detonation front. Type Ia supernova modelers often use one- dimensional DNS of detonations as inputs or constraints for their whole star simulations. While these one-dimensional studies are useful tools, the true nature of the detonation is multi-dimensional. The multi-dimensional structure of the burning influences the speed, stability, and the composition of the detonation and its burning products, and therefore, could have an impact on the spectra of Type Ia supernovae. Considerablemore » effort has been expended modeling Type Ia supernovae at densities above 1x10 7 g∙cm -3 where the complexities of turbulent burning dominate the flame propagation. However, most full star models turn the nuclear burning schemes off when the density falls below 1x10 7 g∙cm -3 and distributed burning begins. The deflagration to detonation transition (DDT) is believed to occur at just these densities and consequently they are the densities important for studying the properties of the subsequent detonation. In conclusion, this work reviews the status of DNS studies of detonations and their possible implications for Type Ia supernova models. It will cover the development of Detonation theory from the first simple Chapman-Jouguet (CJ) detonation models to the current models based on the time-dependent, compressible, reactive flow Euler equations of fluid dynamics.« less

  14. The radiologist's workflow environment: evaluation of disruptors and potential implications.

    PubMed

    Yu, John-Paul J; Kansagra, Akash P; Mongan, John

    2014-06-01

    Workflow interruptions in the health care delivery environment are a major contributor to medical errors and have been extensively studied within numerous hospital settings, including the nursing environment and the operating room, along with their effects on physician workflow. Less understood, though, is the role of interruptions in other highly specialized clinical domains and subspecialty services, such as diagnostic radiology. The workflow of the on-call radiologist, in particular, is especially susceptible to disruption by telephone calls and other modes of physician-to-physician communication. Herein, the authors describe their initial efforts to quantify the degree of interruption experienced by on-call radiologists and examine its potential implications in patient safety and overall clinical care. Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  15. Key issues review: numerical studies of turbulence in stars

    NASA Astrophysics Data System (ADS)

    Arnett, W. David; Meakin, Casey

    2016-10-01

    Three major problems of single-star astrophysics are convection, magnetic fields and rotation. Numerical simulations of convection in stars now have sufficient resolution to be truly turbulent, with effective Reynolds numbers of \\text{Re}>{{10}4} , and some turbulent boundary layers have been resolved. Implications of these developments are discussed for stellar structure, evolution and explosion as supernovae. Methods for three-dimensional (3D) simulations of stars are compared and discussed for 3D atmospheres, solar rotation, core-collapse and stellar boundary layers. Reynolds-averaged Navier-Stokes (RANS) analysis of the numerical simulations has been shown to provide a novel and quantitative estimate of resolution errors. Present treatments of stellar boundaries require revision, even for early burning stages (e.g. for mixing regions during He-burning). As stellar core-collapse is approached, asymmetry and fluctuations grow, rendering spherically symmetric models of progenitors more unrealistic. Numerical resolution of several different types of three-dimensional (3D) stellar simulations are compared; it is suggested that core-collapse simulations may be under-resolved. The Rayleigh-Taylor instability in explosions has a deep connection to convection, for which the abundance structure in supernova remnants may provide evidence.

  16. Co-evolution of landforms and vegetation under the influence of orographic precipitation

    NASA Astrophysics Data System (ADS)

    Yetemen, Omer; Srivastava, Ankur; Saco, Patricia M.

    2017-04-01

    Landforms are controlled by the interaction between tectonics, climate, and vegetation. Orography induced precipitation not only has implications on erosion resistance through vegetation dynamics but also affects erosive forces through modifying runoff production. The implications of elevated precipitation due to orography on landscape morphology requires a numerical framework that integrates a range of ecohydrologic and geomorphic processes to explore the competition between erosive and resisting forces in catchments where pronounced orographic precipitation prevails. In this study, our aim was to realistically represent ecohydrology driven by orographic precipitation and explore its implications on landscape evolution through a numerical model. The model was used to investigate how ecohydro-geomorphic differences caused by differential precipitation patterns as a result of orographic influence and rain-shadow effect lead to differences in the organization of modelled topography, soil moisture, and plant biomass. We use the CHILD landscape evolution model equipped with a vegetation dynamics component that explicitly tracks above- and below-ground biomass, and a precipitation forcing component that simulates rainfall as a function of elevation and orientation. The preliminary results of the model have shown how the competition between an increased shear stress through runoff production and an enhanced resistance force due to denser canopy cover, shape the landscape. Hillslope asymmetry between polar- and equator-facing hillslopes are enhanced (diminished) when they coincide with windward (leeward) side of the mountain series. The mountain divide accommodates itself by migrating toward the windward direction to increase (decrease) hillslope gradients on windward (leeward) slopes. These results clearly demonstrate the strong coupling between landform evolution and climate processes.

  17. Dynamical conductivity at the dirty superconductor-metal quantum phase transition

    NASA Astrophysics Data System (ADS)

    Hoyos, J. A.; Del Maestro, Adrian; Rosenow, Bernd; Vojta, Thomas

    2011-03-01

    We study the transport properties of ultrathin disordered nanowires in the neighborhood of the superconductor-metal quantum phase transition. To this end we combine numerical calculations with analytical strong-disorder renormalization group results. The quantum critical conductivity at zero temperature diverges logarithmically as a function of frequency. In the metallic phase, it obeys activated scaling associated with an infinite-randomness quantum critical point. We extend the scaling theory to higher dimensions and discuss implications for experiments. Financial support: Fapesp, CNPq, NSF, and Research Corporation.

  18. Gauge invariant lattice quantum field theory: Implications for statistical properties of high frequency financial markets

    NASA Astrophysics Data System (ADS)

    Dupoyet, B.; Fiebig, H. R.; Musgrove, D. P.

    2010-01-01

    We report on initial studies of a quantum field theory defined on a lattice with multi-ladder geometry and the dilation group as a local gauge symmetry. The model is relevant in the cross-disciplinary area of econophysics. A corresponding proposal by Ilinski aimed at gauge modeling in non-equilibrium pricing is implemented in a numerical simulation. We arrive at a probability distribution of relative gains which matches the high frequency historical data of the NASDAQ stock exchange index.

  19. β-Blocker pharmacogenetics in heart failure

    PubMed Central

    Shin, Jaekyu

    2009-01-01

    β-Blockers (metoprolol, bisoprolol, and carvedilol) are a cornerstone of heart failure (HF) treatment. However, it is well recognized that responses to a β-blocker are variable among patients with HF. Numerous studies now suggest that genetic polymorphisms may contribute to variability in responses to a β-blocker, including left ventricular ejection fraction improvement, survival, and hospitalization due to HF exacerbation. This review summarizes the pharmacogenetic data for β-blockers in patients with HF and discusses the potential implications of β-blocker pharmacogenetics for HF patients. PMID:18437562

  20. Family Formation Processes: Assessing the Need for a New Nationally Representative Household Panel Survey in the United States

    PubMed Central

    Manning, Wendy D.

    2015-01-01

    The American family has undergone rapid transformation. Careful measurement attention to family formation is important because families are at the heart of numerous decisions, roles, and responsibilities with implications for understanding the well-being of families, adults and children. This paper considers whether there is a need for a new household panel study that addresses family formation. This paper consists of a review of the recent body of population-based, American surveys and finds a considerable gap in the ability to study the implications of families for the health and well-being of Americans. Earlier panel surveys used to assess family life anchored questions around marital events, but changes in family patterns require attention to a more diverse set of family forms. The paper concludes with recommendations for a multi-purpose panel study. The key challenge is to keep to pace with complexity and changes in American family life while at the same time maintaining a parsimonious set of survey questions. PMID:26612969

  1. Delaware Longitudinal Study of Fraction Learning: Implications for Helping Children With Mathematics Difficulties.

    PubMed

    Jordan, Nancy C; Resnick, Ilyse; Rodrigues, Jessica; Hansen, Nicole; Dyson, Nancy

    The goal of the present article is to synthesize findings to date from the Delaware Longitudinal Study of Fraction Learning. The study followed a large cohort of children ( N = 536) between Grades 3 and 6. The findings showed that many students, especially those with diagnosed learning disabilities, made minimal growth in fraction knowledge and that some showed only a basic grasp of the meaning of a fraction even after several years of instruction. Children with low growth in fraction knowledge during the intermediate grades were much more likely to fail to meet state standards on a broad mathematics measure at the end of Grade 6. Although a range of general and mathematics-specific competencies predicted fraction outcomes, the ability to estimate numerical magnitudes on a number line was a uniquely important marker of fraction success. Many children with mathematics difficulties have deep-seated problems related to whole number magnitude representations that are complicated by the introduction of fractions into the curriculum. Implications for helping students with mathematics difficulties are discussed.

  2. Comment on “Symplectic integration of magnetic systems”: A proof that the Boris algorithm is not variational

    DOE PAGES

    Ellison, C. L.; Burby, J. W.; Qin, H.

    2015-11-01

    One popular technique for the numerical time advance of charged particles interacting with electric and magnetic fields according to the Lorentz force law [1], [2], [3] and [4] is the Boris algorithm. Its popularity stems from simple implementation, rapid iteration, and excellent long-term numerical fidelity [1] and [5]. Excellent long-term behavior strongly suggests the numerical dynamics exhibit conservation laws analogous to those governing the continuous Lorentz force system [6]. Moreover, without conserved quantities to constrain the numerical dynamics, algorithms typically dissipate or accumulate important observables such as energy and momentum over long periods of simulated time [6]. Identification of themore » conservative properties of an algorithm is important for establishing rigorous expectations on the long-term behavior; energy-preserving, symplectic, and volume-preserving methods each have particular implications for the qualitative numerical behavior [6], [7], [8], [9], [10] and [11].« less

  3. Dynamical approach study of spurious steady-state numerical solutions of nonlinear differential equations. I - The dynamics of time discretization and its implications for algorithm development in computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Sweby, P. K.; Griffiths, D. F.

    1991-01-01

    Spurious stable as well as unstable steady state numerical solutions, spurious asymptotic numerical solutions of higher period, and even stable chaotic behavior can occur when finite difference methods are used to solve nonlinear differential equations (DE) numerically. The occurrence of spurious asymptotes is independent of whether the DE possesses a unique steady state or has additional periodic solutions and/or exhibits chaotic phenomena. The form of the nonlinear DEs and the type of numerical schemes are the determining factor. In addition, the occurrence of spurious steady states is not restricted to the time steps that are beyond the linearized stability limit of the scheme. In many instances, it can occur below the linearized stability limit. Therefore, it is essential for practitioners in computational sciences to be knowledgeable about the dynamical behavior of finite difference methods for nonlinear scalar DEs before the actual application of these methods to practical computations. It is also important to change the traditional way of thinking and practices when dealing with genuinely nonlinear problems. In the past, spurious asymptotes were observed in numerical computations but tended to be ignored because they all were assumed to lie beyond the linearized stability limits of the time step parameter delta t. As can be seen from the study, bifurcations to and from spurious asymptotic solutions and transitions to computational instability not only are highly scheme dependent and problem dependent, but also initial data and boundary condition dependent, and not limited to time steps that are beyond the linearized stability limit.

  4. Tidal asymmetry and residual circulation over linear sandbanks and their implication on sediment transport: a process-oriented numerical study

    USGS Publications Warehouse

    Sanay, Rosario; Voulgaris, George; Warner, John C.

    2007-01-01

    A series of process-oriented numerical simulations is carried out in order to evaluate the relative role of locally generated residual flow and overtides on net sediment transport over linear sandbanks. The idealized bathymetry and forcing are similar to those present in the Norfolk Sandbanks, North Sea. The importance of bottom drag parameterization and bank orientation with respect to the ambient flow is examined in terms of residual flow and overtide generation, and subsequent sediment transport implications are discussed. The results show that although the magnitudes of residual flow and overtides are sensitive to bottom roughness parameterization and bank orientation, the magnitude of the generated residual flow is always larger than that of the locally generated overtides. Also, net sediment transport is always dominated by the nonlinear interaction of the residual flow and the semidiurnal tidal currents, although cross-bank sediment transport can occur even in the absence of a cross-shore residual flow. On the other hand, net sediment divergence/convergence increases as the bottom drag decreases and as bank orientation increases. The sediment erosion/deposition is not symmetric about the crest of the bank, suggesting that originally symmetric banks would have the tendency to become asymmetric.

  5. Development of early numerical abilities of Spanish-speaking Mexican preschoolers: A new assessment tool.

    PubMed

    Beltrán-Navarro, Beatriz; Abreu-Mendoza, Roberto A; Matute, Esmeralda; Rosselli, Monica

    2018-01-01

    This article presents a tool for assessing the early numerical abilities of Spanish-speaking Mexican preschoolers. The Numerical Abilities Test, from the Evaluación Neuropsicológica Infantil-Preescolar (ENI-P), evaluates four core abilities of number development: magnitude comparison, counting, subitizing, and basic calculation. We evaluated 307 Spanish-speaking Mexican children aged 2 years 6 months to 4 years 11 months. Appropriate internal consistency and test-retest reliability were demonstrated. We also investigated the effect of age, children's school attendance, maternal education, and sex on children's numerical scores. The results showed that the four subtests captured development across ages. Critically, maternal education had an impact on children's performance in three out of the four subtests, but there was no effect associated with children's school attendance or sex. These results suggest that the Numerical Abilities Test is a reliable instrument for Spanish-speaking preschoolers. We discuss the implications of our outcomes for numerical development.

  6. Update of MMT assessment

    EPA Science Inventory

    Methylcyclopentadienyl manganese tricarbonyl (MMT) is added to gasoline to increase its octane rating. As a metal additive with potential for widespread use and manganese (Mn) exposure implications, MMT has been the focus of numerous analyses and debates about its potential publi...

  7. Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots.

    PubMed

    Ortega Ancel, Alejandro; Eastwood, Rodney; Vogt, Daniel; Ithier, Carter; Smith, Michael; Wood, Rob; Kovač, Mirko

    2017-02-06

    Many insects are well adapted to long-distance migration despite the larger energetic costs of flight for small body sizes. To optimize wing design for next-generation flying micro-robots, we analyse butterfly wing shapes and wing orientations at full scale using numerical simulations and in a low-speed wind tunnel at 2, 3.5 and 5 m s -1 . The results indicate that wing orientations which maximize wing span lead to the highest glide performance, with lift to drag ratios up to 6.28, while spreading the fore-wings forward can increase the maximum lift produced and thus improve versatility. We discuss the implications for flying micro-robots and how the results assist in understanding the behaviour of the butterfly species tested.

  8. Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots

    PubMed Central

    Eastwood, Rodney; Vogt, Daniel; Ithier, Carter; Smith, Michael; Wood, Rob; Kovač, Mirko

    2017-01-01

    Many insects are well adapted to long-distance migration despite the larger energetic costs of flight for small body sizes. To optimize wing design for next-generation flying micro-robots, we analyse butterfly wing shapes and wing orientations at full scale using numerical simulations and in a low-speed wind tunnel at 2, 3.5 and 5 m s−1. The results indicate that wing orientations which maximize wing span lead to the highest glide performance, with lift to drag ratios up to 6.28, while spreading the fore-wings forward can increase the maximum lift produced and thus improve versatility. We discuss the implications for flying micro-robots and how the results assist in understanding the behaviour of the butterfly species tested. PMID:28163879

  9. Numerical Study of Rotating Turbulence with External Forcing

    NASA Technical Reports Server (NTRS)

    Yeung, P. K.; Zhou, Ye

    1998-01-01

    Direct numerical simulation at 256(exp 3) resolution have been carried out to study the response of isotropic turbulence to the concurrent effects of solid-body rotation and numerical forcing at the large scales. Because energy transfer to the smaller scales is weakened by rotation, energy input from forcing gradually builds up at the large scales, causing the overall kinetic energy to increase. At intermediate wavenumbers the energy spectrum undergoes a transition from a limited k(exp -5/3) inertial range to k(exp -2) scaling recently predicted in the literature. Although the Reynolds stress tensor remains approximately isotropic and three-components, evidence for anisotropy and quasi- two-dimensionality in length scales and spectra in different velocity components and directions is strong. The small scales are found to deviate from local isotropy, primarily as a result of anisotropic transfer to the high wavenumbers. To understand the spectral dynamics of this flow we study the detailed behavior of nonlinear triadic interactions in wavenumber space. Spectral transfer in the velocity component parallel to the axis of rotation is qualitatively similar to that in non-rotating turbulence; however the perpendicular component is characterized by a greatly suppressed energy cascade at high wavenumber and a local reverse transfer at the largest scales. The broader implications of this work are briefly addressed.

  10. Descriptive and numeric estimation of risk for psychotic disorders among affected individuals and relatives: Implications for clinical practice

    PubMed Central

    Austin, Jehannine C.; Hippman, Catriona; Honer, William G.

    2013-01-01

    Studies show that individuals with psychotic illnesses and their families want information about psychosis risks for other relatives. However, deriving accurate numeric probabilities for psychosis risk is challenging, and people have difficulty interpreting probabilistic information, thus some have suggested that clinicians should use risk descriptors, such as ‘moderate’ or ‘quite high’, rather than numbers. Little is known about how individuals with psychosis and their family members use quantitative and qualitative descriptors of risk in the specific context of chance for an individual to develop psychosis. We explored numeric and descriptive estimations of psychosis risk among individuals with psychotic disorders and unaffected first-degree relatives. In an online survey, respondents numerically and descriptively estimated risk for an individual to develop psychosis in scenarios where they had: A) no affected family members; and B) an affected sibling. 219 affected individuals and 211 first-degree relatives participated. Affected individuals estimated significantly higher risks than relatives. Participants attributed all descriptors between “very low” and “very high” to probabilities of 1%, 10%, 25% and 50%+. For a given numeric probability, different risk descriptors were attributed in different scenarios. Clinically, brief interventions around risk (using either probabilities or descriptors alone) are vulnerable to miscommunication and potentially profoundly negative consequences –interventions around risk are best suited to in-depth discussion. PMID:22421074

  11. Descriptive and numeric estimation of risk for psychotic disorders among affected individuals and relatives: implications for clinical practice.

    PubMed

    Austin, Jehannine C; Hippman, Catriona; Honer, William G

    2012-03-30

    Studies show that individuals with psychotic illnesses and their families want information about psychosis risks for other relatives. However, deriving accurate numeric probabilities for psychosis risk is challenging, and people have difficulty interpreting probabilistic information; thus, some have suggested that clinicians should use risk descriptors, such as "moderate" or "quite high", rather than numbers. Little is known about how individuals with psychosis and their family members use quantitative and qualitative descriptors of risk in the specific context of chance for an individual to develop psychosis. We explored numeric and descriptive estimations of psychosis risk among individuals with psychotic disorders and unaffected first-degree relatives. In an online survey, respondents numerically and descriptively estimated risk for an individual to develop psychosis in scenarios where they had: A) no affected family members; and B) an affected sibling. Participants comprised 219 affected individuals and 211 first-degree relatives participated. Affected individuals estimated significantly higher risks than relatives. Participants attributed all descriptors between "very low" and "very high" to probabilities of 1%, 10%, 25% and 50%+. For a given numeric probability, different risk descriptors were attributed in different scenarios. Clinically, brief interventions around risk (using either probabilities or descriptors alone) are vulnerable to miscommunication and potentially negative consequences-interventions around risk are best suited to in-depth discussion. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Predicting and understanding undergraduate students' intentions to gamble in a casino using an extended model of the theory of reasoned action and the theory of planned behavior.

    PubMed

    Lee, Hyung-Seok

    2013-06-01

    Given that current television programming contains numerous gambling portrayals, it is imperative to understand whether and to what extent these gambling behaviors in media influence individuals' beliefs, attitudes, and intentions. This study explores an extended model of the theory of reasoned action (TRA) by including gambling media exposure as a distal, mediating and mediated factor in predicting undergraduate students' intentions to gamble in a casino. Findings show that the extended model of TRA clearly indicates that the constructs of gambling media exposure, prior gambling experience, and level of gambling addiction contribute to the prediction of undergraduate students' casino gambling intentions. Theoretical implications of gambling media effects and practical implications for public policy are discussed, and future research directions are outlined.

  13. The calculating brain: an fMRI study.

    PubMed

    Rickard, T C; Romero, S G; Basso, G; Wharton, C; Flitman, S; Grafman, J

    2000-01-01

    To explore brain areas involved in basic numerical computation, functional magnetic imaging (fMRI) scanning was performed on college students during performance of three tasks; simple arithmetic, numerical magnitude judgment, and a perceptual-motor control task. For the arithmetic relative to the other tasks, results for all eight subjects revealed bilateral activation in Brodmann's area 44, in dorsolateral prefrontal cortex (areas 9 and 10), in inferior and superior parietal areas, and in lingual and fusiform gyri. Activation was stronger on the left for all subjects, but only at Brodmann's area 44 and the parietal cortices. No activation was observed in the arithmetic task in several other areas previously implicated for arithmetic, including the angular and supramarginal gyri and the basal ganglia. In fact, angular and supramarginal gyri were significantly deactivated by the verification task relative to both the magnitude judgment and control tasks for every subject. Areas activated by the magnitude task relative to the control were more variable, but in five subjects included bilateral inferior parietal cortex. These results confirm some existing hypotheses regarding the neural basis of numerical processes, invite revision of others, and suggest productive lines for future investigation.

  14. Measurement and modeling of the acoustic field near an underwater vehicle and implications for acoustic source localization.

    PubMed

    Lepper, Paul A; D'Spain, Gerald L

    2007-08-01

    The performance of traditional techniques of passive localization in ocean acoustics such as time-of-arrival (phase differences) and amplitude ratios measured by multiple receivers may be degraded when the receivers are placed on an underwater vehicle due to effects of scattering. However, knowledge of the interference pattern caused by scattering provides a potential enhancement to traditional source localization techniques. Results based on a study using data from a multi-element receiving array mounted on the inner shroud of an autonomous underwater vehicle show that scattering causes the localization ambiguities (side lobes) to decrease in overall level and to move closer to the true source location, thereby improving localization performance, for signals in the frequency band 2-8 kHz. These measurements are compared with numerical modeling results from a two-dimensional time domain finite difference scheme for scattering from two fluid-loaded cylindrical shells. Measured and numerically modeled results are presented for multiple source aspect angles and frequencies. Matched field processing techniques quantify the source localization capabilities for both measurements and numerical modeling output.

  15. Contention between supply of hydrothermal fluid and conduit obstruction: inferences from numerical simulations

    NASA Astrophysics Data System (ADS)

    Tanaka, Ryo; Hashimoto, Takeshi; Matsushima, Nobuo; Ishido, Tsuneo

    2018-05-01

    We investigate a volcanic hydrothermal system using numerical simulations, focusing on change in crater temperature. Both increases and decreases in crater temperature have been observed before phreatic eruptions. We follow the system's response for up to a decade after hydrothermal fluid flux from the deep part of the system is increased and permeability is reduced at a certain depth in a conduit. Our numerical simulations demonstrate that: (1) changes in crater temperature are controlled by the magnitude of the increase in hydrothermal fluid flux and the degree of permeability reduction; (2) significant increases in hydrothermal flux with decreases in permeability induce substantial pressure changes in shallow depths in the edifice and decreases in crater temperature; (3) the location of maximum pressure change differs between the mechanisms. The results of this study imply that it is difficult to predict eruptions by crater temperature change alone. One should be as wary of large eruptions when crater temperature decreases as when crater temperature increases. It is possible to clarify the implications of changes in crater temperature with simultaneous observation of ground deformation.[Figure not available: see fulltext.

  16. The prevalence of early postpartum psychiatric morbidity in Dubai: a transcultural perspective.

    PubMed

    Abou-Saleh, M T; Ghubash, R

    1997-05-01

    There have been numerous studies of the prevalence of postpartum psychiatric illness and its putative risk factors in Western Europe and North America, but very few studies have been undertaken in developing countries, including the Arab world. A total of 95 women admitted to the New Dubai Hospital in Dubai, United Arab Emirates, for childbirth were studied. All subjects were assessed in the postpartum period using clinical and socio-cultural instruments, namely the Self-Reporting Questionnaire (SRQ) on day 2 and the Edinburgh Postnatal Depression Scale (EPDS) on day 7 after delivery. The prevalence of psychiatric morbidity was 24% according to the SRQ and 18% according to the EPDS. A number of psychosocial factors emerged as putative risk factors for postpartum psychiatric disturbance, including depressive illness. It is concluded that the prevalence of postpartum psychiatric morbidity and its risk factors in this Arab culture are similar to the results obtained in numerous previous studies conducted in industrialized countries. These findings have implications for the early detection and care of women at risk for postpartum psychiatric illness.

  17. Postpartum psychiatric illness in Arab culture: prevalence and psychosocial correlates.

    PubMed

    Ghubash, R; Abou-Saleh, M T

    1997-07-01

    There have been numerous studies of the prevalence of postpartum depression and its putative risk factors in Western Europe and North America, but very few studies in developing countries including the Arab world. Ninety-five women admitted to the New Dubai Hospital in Dubai, United Arab Emirates, for childbirth were studied. All subjects were assessed in the postpartum period using clinical and socio-cultural instruments: the Self Report Questionnaire (SRQ) at day 2, the Edinburgh Postnatal Depression Scale (EPDS) at day 7, and the Present State Examination (PSE) at week 8 +/- 2 and week 30 +/- 2 after delivery. The prevalence rate of psychiatric morbidity was 24.5% by the SRQ, 17.8% by the EPDS, and 15.8% by the PSE. A number of psychosocial factors emerged as putative risk factors for postpartum depression. The prevalence rates of postpartum psychiatric morbidity and its risk factors in this Arab culture are similar to the results obtained in numerous previous studies in industrialised countries. These findings have implications for the early detection and care of women at risk for postpartum depression.

  18. Cross-format physical similarity effects and their implications for the numerical cognition architecture

    PubMed Central

    Cohen, Dale J.; Warren, Erin; Blanc-Goldhammer, Daryn

    2013-01-01

    The sound |faiv| is visually depicted as a written number word “five” and as an Arabic digit “5.” Here, we present four experiments – two quantity same/different experiments and two magnitude comparison experiments – that assess whether auditory number words (|faiv|), written number words (“five”), and Arabic digits (“5”) directly activate one another and/or their associated quantity. The quantity same/different experiments reveal that the auditory number words, written number words, and Arabic digits directly activate one another without activating their associated quantity. That is, there are cross-format physical similarity effects but no numerical distance effects. The cross-format magnitude comparison experiments reveal significant effects of both physical similarity and numerical distance. We discuss these results in relation to the architecture of numerical cognition. PMID:23624377

  19. Obesity in Older Adults: Epidemiology and Implications for Disability and Disease

    PubMed Central

    Samper-Ternent, Rafael; Al Snih, Soham

    2012-01-01

    Summary Obesity is a worldwide problem with increasing prevalence and incidence in both developed and developing countries. In older adults, excess weight is associated with a higher prevalence of cardiovascular disease, metabolic disease, several important cancers, and numerous other medical conditions. Obesity has been also associated with increased functional limitations, disability, and poorer quality of life. Additionally, obesity has been independently associated with all-cause mortality. The obesity epidemic has important social and economic implications, representing an important source of increased public health care costs. The aim of this review is to report the epidemiology of obesity world-wide and the implications of obesity on disability and chronic diseases. PMID:22345902

  20. Implications of Tidally Driven Convection and Lithospheric Arguments on the Topography of Europa

    NASA Astrophysics Data System (ADS)

    Sattler-Cassara, L.; Lyra, W.

    2017-11-01

    We present 3D numerical simulations of tidally driven convection in Europa. By associating the resulting normal stress from plumes with surface weakening and resistance from shallower layers, we successfully reproduce domes and double ridges.

  1. Meso-beta scale numerical simulation studies of terrain-induced jet streak mass and momentum perturbations

    NASA Technical Reports Server (NTRS)

    Lin, Yuh-Lang; Kaplan, Michael L.

    1994-01-01

    An in-depth analysis of observed gravity waves and their relationship to precipitation bands over the Montana mesonetwork during the 11-12 July 1981 CCOPE case study indicated two episodes of coherent waves. While geostrophic adjustment, shearing instability, and terrain were all implicated separately or in combination as possible wave generation mechanisms, the lack of upper-air data within the wave genesis region made it difficult to define the genesis processes from observations alone. The first part of this paper, 3D Numerical Modeling Studies of Terrain-Induced Mass/Momentum Perturbations, employs a mesoscale numerical model to help diagnose the intricate early wave generation mechanisms during the first observed gravity wave episode. The meso-beta scale numerical model is used to study various simulations of the role of multiple geostrophic adjustment processes in focusing a region for gravity wave genesis. The second part of this paper, Linear Theory and Theoretical Modeling, investigates the response of non-resting rotating homogeneous and continuously stratified Boussinesq models of the terrestrial atmosphere to temporally impulsive and uniformly propagating three-dimensional localized zonal momentum sources representative of midlatitude jet streaks. The methods of linear perturbation theory applied to the potential vorticity (PV) and wave field equations are used to study the geostrophic adjustment dynamics. The total zonal and meridional wind perturbations are separated into geostrophic and ageostrophic components in order to define and follow the evolution of both the primary and secondary mesocirculations accompanying midlatitude jetogenesis forced by geostrophic adjustment processes. This problem is addressed to help fill the gap in understanding the dynamics and structure of mesoscale inertia-gravity waves forced by geostrophic adjustment processes in simple two-dimensional quiescent current systems and those produced by mesoscale numerical models simulating the orographic and diabatic perturbation of three-dimensional quasi-geostrophically balanced synoptic scale jet streaks associated with complex baroclinic severe storm producing environments.

  2. Dispositional Mindfulness Uncouples Physiological and Emotional Reactivity to a Laboratory Stressor and Emotional Reactivity to Executive Functioning Lapses in Daily Life

    PubMed Central

    Feldman, Greg; Lavalle, Jayne; Gildawie, Kelsea; Greeson, Jeffrey M.

    2016-01-01

    Both dispositional mindfulness and mindfulness training may help to uncouple the degree to which distress is experienced in response to aversive internal experience and external events. Because emotional reactivity is a transdiagnostic process implicated in numerous psychological disorders, dispositional mindfulness and mindfulness training could exert mental health benefits, in part, by buffering emotional reactivity. The present studies examine whether dispositional mindfulness moderates two understudied processes in stress reactivity research: the degree of concordance between subjective and physiological reactivity to a laboratory stressor (Study 1); and the degree of dysphoric mood reactivity to lapses in executive functioning in daily life (Study 2). In both studies, lower emotional reactivity to aversive experiences was observed among individuals scoring higher in mindfulness, particularly non-judging, relative to those scoring lower in mindfulness. These findings support the hypothesis that higher dispositional mindfulness fosters lower emotional reactivity. Results are discussed in terms of implications for applying mindfulness-based interventions to a range of psychological disorders in which people have difficulty regulating emotional reactions to stress. PMID:27087863

  3. Dispositional Mindfulness Uncouples Physiological and Emotional Reactivity to a Laboratory Stressor and Emotional Reactivity to Executive Functioning Lapses in Daily Life.

    PubMed

    Feldman, Greg; Lavalle, Jayne; Gildawie, Kelsea; Greeson, Jeffrey M

    2016-04-01

    Both dispositional mindfulness and mindfulness training may help to uncouple the degree to which distress is experienced in response to aversive internal experience and external events. Because emotional reactivity is a transdiagnostic process implicated in numerous psychological disorders, dispositional mindfulness and mindfulness training could exert mental health benefits, in part, by buffering emotional reactivity. The present studies examine whether dispositional mindfulness moderates two understudied processes in stress reactivity research: the degree of concordance between subjective and physiological reactivity to a laboratory stressor (Study 1); and the degree of dysphoric mood reactivity to lapses in executive functioning in daily life (Study 2). In both studies, lower emotional reactivity to aversive experiences was observed among individuals scoring higher in mindfulness, particularly non-judging, relative to those scoring lower in mindfulness. These findings support the hypothesis that higher dispositional mindfulness fosters lower emotional reactivity. Results are discussed in terms of implications for applying mindfulness-based interventions to a range of psychological disorders in which people have difficulty regulating emotional reactions to stress.

  4. All the “RAGE” in lung disease: The receptor for advanced glycation endproducts (RAGE) is a major mediator of pulmonary inflammatory responses

    PubMed Central

    Oczypok, Elizabeth A.; Perkins, Timothy N.; Oury, Tim D.

    2017-01-01

    SUMMARY The receptor for advanced glycation endproducts (RAGE) is a pro-inflammatory pattern recognition receptor (PRR) that has been implicated in the pathogenesis of numerous inflammatory diseases. It was discovered in 1992 on endothelial cells and was named for its ability to bind advanced glycation endproducts and promote vascular inflammation in the vessels of patients with diabetes. Further studies revealed that RAGE is most highly expressed in lung tissue and spurred numerous explorations into RAGE’s role in the lung. These studies have found that RAGE is an important mediator in allergic airway inflammation (AAI) and asthma, pulmonary fibrosis, lung cancer, chronic obstructive pulmonary disease (COPD), acute lung injury, pneumonia, cystic fibrosis, and bronchopulmonary dysplasia. RAGE has not yet been targeted in the lungs of paediatric or adult clinical populations, but the development of new ways to inhibit RAGE is setting the stage for the emergence of novel therapeutic agents for patients suffering from these pulmonary conditions. PMID:28416135

  5. Multiple Phosphatases Regulate Carbon Source-Dependent Germination and Primary Metabolism in Aspergillus nidulans

    PubMed Central

    de Assis, Leandro José; Ries, Laure Nicolas Annick; Savoldi, Marcela; Dinamarco, Taisa Magnani; Goldman, Gustavo Henrique; Brown, Neil Andrew

    2015-01-01

    Aspergillus nidulans is an important mold and a model system for the study of fungal cell biology. In addition, invasive A. nidulans pulmonary infections are common in humans with chronic granulomatous disease. The morphological and biochemical transition from dormant conidia into active, growing, filamentous hyphae requires the coordination of numerous biosynthetic, developmental, and metabolic processes. The present study exhibited the diversity of roles performed by seven phosphatases in regulating cell cycle, development, and metabolism in response to glucose and alternative carbon sources. The identified phosphatases highlighted the importance of several signaling pathways regulating filamentous growth, the action of the pyruvate dehydrogenase complex as a metabolic switch controlling carbon usage, and the identification of the key function performed by the α-ketoglutarate dehydrogenase during germination. These novel insights into the fundamental roles of numerous phosphatases in germination and carbon sensing have provided new avenues of research into the identification of inhibitors of fungal germination, with implications for the food, feed, and pharmaceutical industries. PMID:25762568

  6. Virus-Bacteria Interactions: Implications and Potential for the Applied and Agricultural Sciences.

    PubMed

    Moore, Matthew D; Jaykus, Lee-Ann

    2018-02-02

    Eukaryotic virus-bacteria interactions have recently become an emerging topic of study due to multiple significant examples related to human pathogens of clinical interest. However, such omnipresent and likely important interactions for viruses and bacteria relevant to the applied and agricultural sciences have not been reviewed or compiled. The fundamental basis of this review is that these interactions have importance and deserve more investigation, as numerous potential consequences and applications arising from their discovery are relevant to the applied sciences. The purpose of this review is to highlight and summarize eukaryotic virus-bacteria findings in the food/water, horticultural, and animal sciences. In many cases in the agricultural sciences, mechanistic understandings of the effects of virus-bacteria interactions remain unstudied, and many studies solely focus on co-infections of bacterial and viral pathogens. Given recent findings relative to human viral pathogens, further research related to virus-bacteria interactions would likely result in numerous discoveries and beneficial applications.

  7. Decoding the patterns of ubiquitin recognition by ubiquitin-associated domains from free energy simulations.

    PubMed

    Bouvier, Benjamin

    2014-01-07

    Ubiquitin is a highly conserved, highly represented protein acting as a regulating signal in numerous cellular processes. It leverages a single hydrophobic binding patch to recognize and bind a large variety of protein domains with remarkable specificity, but can also self-assemble into chains of poly-diubiquitin units in which these interfaces are sequestered, profoundly altering the individual monomers' recognition characteristics. Despite numerous studies, the origins of this varied specificity and the competition between substrates for the binding of the ubiquitin interface patch remain under heated debate. This study uses enhanced sampling all-atom molecular dynamics to simulate the unbinding of complexes of mono- or K48-linked diubiquitin bound to several ubiquitin-associated domains, providing insights into the mechanism and free energetics of ubiquitin recognition and binding. The implications for the subtle tradeoff between the stability of the polyubiquitin signal and its easy recognition by target protein assemblies are discussed, as is the enhanced affinity of the latter for long polyubiquitin chains compared to isolated mono- or diubiquitin.

  8. An integrated map of structural variation in 2,504 human genomes.

    PubMed

    Sudmant, Peter H; Rausch, Tobias; Gardner, Eugene J; Handsaker, Robert E; Abyzov, Alexej; Huddleston, John; Zhang, Yan; Ye, Kai; Jun, Goo; Fritz, Markus Hsi-Yang; Konkel, Miriam K; Malhotra, Ankit; Stütz, Adrian M; Shi, Xinghua; Casale, Francesco Paolo; Chen, Jieming; Hormozdiari, Fereydoun; Dayama, Gargi; Chen, Ken; Malig, Maika; Chaisson, Mark J P; Walter, Klaudia; Meiers, Sascha; Kashin, Seva; Garrison, Erik; Auton, Adam; Lam, Hugo Y K; Mu, Xinmeng Jasmine; Alkan, Can; Antaki, Danny; Bae, Taejeong; Cerveira, Eliza; Chines, Peter; Chong, Zechen; Clarke, Laura; Dal, Elif; Ding, Li; Emery, Sarah; Fan, Xian; Gujral, Madhusudan; Kahveci, Fatma; Kidd, Jeffrey M; Kong, Yu; Lameijer, Eric-Wubbo; McCarthy, Shane; Flicek, Paul; Gibbs, Richard A; Marth, Gabor; Mason, Christopher E; Menelaou, Androniki; Muzny, Donna M; Nelson, Bradley J; Noor, Amina; Parrish, Nicholas F; Pendleton, Matthew; Quitadamo, Andrew; Raeder, Benjamin; Schadt, Eric E; Romanovitch, Mallory; Schlattl, Andreas; Sebra, Robert; Shabalin, Andrey A; Untergasser, Andreas; Walker, Jerilyn A; Wang, Min; Yu, Fuli; Zhang, Chengsheng; Zhang, Jing; Zheng-Bradley, Xiangqun; Zhou, Wanding; Zichner, Thomas; Sebat, Jonathan; Batzer, Mark A; McCarroll, Steven A; Mills, Ryan E; Gerstein, Mark B; Bashir, Ali; Stegle, Oliver; Devine, Scott E; Lee, Charles; Eichler, Evan E; Korbel, Jan O

    2015-10-01

    Structural variants are implicated in numerous diseases and make up the majority of varying nucleotides among human genomes. Here we describe an integrated set of eight structural variant classes comprising both balanced and unbalanced variants, which we constructed using short-read DNA sequencing data and statistically phased onto haplotype blocks in 26 human populations. Analysing this set, we identify numerous gene-intersecting structural variants exhibiting population stratification and describe naturally occurring homozygous gene knockouts that suggest the dispensability of a variety of human genes. We demonstrate that structural variants are enriched on haplotypes identified by genome-wide association studies and exhibit enrichment for expression quantitative trait loci. Additionally, we uncover appreciable levels of structural variant complexity at different scales, including genic loci subject to clusters of repeated rearrangement and complex structural variants with multiple breakpoints likely to have formed through individual mutational events. Our catalogue will enhance future studies into structural variant demography, functional impact and disease association.

  9. Communicating Numerical Risk: Human Factors That Aid Understanding in Health Care

    PubMed Central

    Brust-Renck, Priscila G.; Royer, Caisa E.; Reyna, Valerie F.

    2014-01-01

    In this chapter, we review evidence from the human factors literature that verbal and visual formats can help increase the understanding of numerical risk information in health care. These visual representations of risk are grounded in empirically supported theory. As background, we first review research showing that people often have difficulty understanding numerical risks and benefits in health information. In particular, we discuss how understanding the meanings of numbers results in healthier decisions. Then, we discuss the processes that determine how communication of numerical risks can enhance (or degrade) health judgments and decisions. Specifically, we examine two different approaches to risk communication: a traditional approach and fuzzy-trace theory. Applying research on the complications of understanding and communicating risks, we then highlight how different visual representations are best suited to communicating different risk messages (i.e., their gist). In particular, we review verbal and visual messages that highlight gist representations that can better communicate health information and improve informed decision making. This discussion is informed by human factors theories and methods, which involve the study of how to maximize the interaction between humans and the tools they use. Finally, we present implications and recommendations for future research on human factors in health care. PMID:24999307

  10. Thought-action fusion: a comprehensive analysis using structural equation modeling.

    PubMed

    Marino, Teresa L; Lunt, Rachael A; Negy, Charles

    2008-07-01

    Thought-action fusion (TAF), the phenomenon whereby one has difficulty separating cognitions from corresponding behaviors, has implications in a wide variety of disturbances, including eating disorders, obsessive-compulsive disorder, generalized anxiety disorder, and panic disorder. Numerous constructs believed to contribute to the etiology or maintenance of TAF have been identified in the literature, but to date, no study has empirically integrated these findings into a comprehensive model. In this study, we examined simultaneously an array of variables thought to be related to TAF, and subsequently developed a model that elucidates the role of those variables that seem most involved in this phenomenon using a structural equation modeling approach. Results indicated that religiosity, as predicted by ethnic identity, was a significant predictor of TAF. Additionally, the relation between ethnic identity and TAF was partially mediated by an inflated sense of responsibility. Both TAF and obsessive-compulsive symptoms were found to be significant predictors of engagement in neutralization activities. Clinical and theoretical implications are discussed.

  11. Parameter uncertainty in simulations of extreme precipitation and attribution studies.

    NASA Astrophysics Data System (ADS)

    Timmermans, B.; Collins, W. D.; O'Brien, T. A.; Risser, M. D.

    2017-12-01

    The attribution of extreme weather events, such as heavy rainfall, to anthropogenic influence involves the analysis of their probability in simulations of climate. The climate models used however, such as the Community Atmosphere Model (CAM), employ approximate physics that gives rise to "parameter uncertainty"—uncertainty about the most accurate or optimal values of numerical parameters within the model. In particular, approximate parameterisations for convective processes are well known to be influential in the simulation of precipitation extremes. Towards examining the impact of this source of uncertainty on attribution studies, we investigate the importance of components—through their associated tuning parameters—of parameterisations relating to deep and shallow convection, and cloud and aerosol microphysics in CAM. We hypothesise that as numerical resolution is increased the change in proportion of variance induced by perturbed parameters associated with the respective components is consistent with the decreasing applicability of the underlying hydrostatic assumptions. For example, that the relative influence of deep convection should diminish as resolution approaches that where convection can be resolved numerically ( 10 km). We quantify the relationship between the relative proportion of variance induced and numerical resolution by conducting computer experiments that examine precipitation extremes over the contiguous U.S. In order to mitigate the enormous computational burden of running ensembles of long climate simulations, we use variable-resolution CAM and employ both extreme value theory and surrogate modelling techniques ("emulators"). We discuss the implications of the relationship between parameterised convective processes and resolution both in the context of attribution studies and progression towards models that fully resolve convection.

  12. Acoustic Wave Monitoring of Biofilm Development in Porous Media

    EPA Science Inventory

    Biofilm development in porous media can result in significant changes to the hydrogeological properties of subsurface systems with implications for fluid flow and contaminant transport. As such, a number of numerical models and simulations have been developed in an attempt to qua...

  13. Methods to measure indicators of exposure in real-world aquatic environments

    EPA Science Inventory

    Most of what is known about the implications of endocrine disrupting chemicals in the environment is somewhat anecdotal. There are numerous reports of gonadal histological abnormalities (Potomac, United Kingdom Rivers), alterations in sex ratios (Boulder Creek, Colorado) and high...

  14. A Comprehensive Survey of China’s Dynamic Shipbuilding Industry: Commercial Development and Strategic Implications (China Maritime Study, Number 1)

    DTIC Science & Technology

    2008-08-01

    A ’ S D Y N A M I C S H I P B U I L D I N G I N D U S T R Y 51 Acronyms and Definitions A AKR commercial cargo ship AO...growth could lead to a bifurcated global ship market, wherein China dominates low-complexity ship construction and South Korea dominates the high ...Efficiently integrating numerous mechanical, electrical, cargo , and habitability systems within the confined space of a ship has always been a

  15. Initial results of experimental studies of prairie dogs in arid grasslands: Implications for landscape conservation and the importance of scale (Resultados Iniciales de Estudios Experimentales en Perros Llaneros de Pastizales Aridos: Implicaciones Para la Conservacion del Paisaje y la Importancia de Escala)

    Treesearch

    Charles Curtin

    2006-01-01

    Numerous ecologists and conservationists believe that prairie dogs increase ecosystem diversity and preserve the function of grasslands (Whicker and Detling 1988, Miller et al. 1994, Jones et al. 1994, Power et al. 1996, Weltzin et al. 1997, Miller et al. 2000), yet this perspective is controversial (Stapp 1998). In contrast, many ranchers and land owners view prairie...

  16. The Relationship of Bacterial Biofilms and Capsular Contracture in Breast Implants

    PubMed Central

    Ajdic, Dragana; Zoghbi, Yasmina; Gerth, David; Panthaki, Zubin J.; Thaller, Seth

    2016-01-01

    Capsular contracture is a common sequelae of implant-based breast augmentation. Despite its prevalence, the etiology of capsular contracture remains controversial. Numerous studies have identified microbial biofilms on various implantable materials, including breast implants. Furthermore, biofilms have been implicated in subclinical infections associated with other surgical implants. In this review, we discuss microbial biofilms as a potential etiology of capsular contracture. The review also outlines the key diagnostic modalities available to identify the possible infectious agents found in biofilm, as well as available preventative and treatment measures. PMID:26843099

  17. Clients' interpretation of risks provided in genetic counseling.

    PubMed Central

    Wertz, D C; Sorenson, J R; Heeren, T C

    1986-01-01

    Clients in 544 genetic counseling sessions who were given numeric risks of having a child with a birth defect between 0% and 50% were asked to interpret these numeric risks on a five-point scale, ranging from very low to very high. Whereas clients' modal interpretation varied directly with numeric risks between 0% and 15%, the modal category of client risk interpretation remained "moderate" at risks between 15% and 50%. Uncertainty about normalcy of the next child increased as numeric risk increased, and few clients were willing to indicate that the child would probably or definitely be affected regardless of the numeric risk. Characteristics associated with clients' "pessimistic" interpretations of risk, identified by stepwise linear regression, included increased numeric risk, discussion in depth during the counseling session of whether they would have a child, have a living affected child, discussion of the effects of an affected child on relationships with client's other children, and seriousness of the disorder in question (causes intellectual impairment). Client interpretations are discussed in terms of recent developments in cognitive theory, including heuristics that influence judgments about risks, and implications for genetic counseling. PMID:3752089

  18. Implication of Two-Coupled Differential Van der Pol Duffing Oscillator in Weak Signal Detection

    NASA Astrophysics Data System (ADS)

    Peng, Hang-hang; Xu, Xue-mei; Yang, Bing-chu; Yin, Lin-zi

    2016-04-01

    The principle of the Van der Pol Duffing oscillator for state transition and for determining critical value is described, which has been studied to indicate that the application of the Van der Pol Duffing oscillator in weak signal detection is feasible. On the basis of this principle, an improved two-coupled differential Van der Pol Duffing oscillator is proposed which can identify signals under any frequency and ameliorate signal-to-noise ratio (SNR). The analytical methods of the proposed model and the construction of the proposed oscillator are introduced in detail. Numerical experiments on the properties of the proposed oscillator compared with those of the Van der Pol Duffing oscillator are carried out. Our numerical simulations have confirmed the analytical treatment. The results demonstrate that this novel oscillator has better detection performance than the Van der Pol Duffing oscillator.

  19. Numerical study of wavelength-swept semiconductor ring lasers: the role of refractive-index nonlinearities in semiconductor optical amplifiers and implications for biomedical imaging applications.

    PubMed

    Bilenca, A; Yun, S H; Tearney, G J; Bouma, B E

    2006-03-15

    Recent results have demonstrated unprecedented wavelength-tuning speed and repetition rate performance of semiconductor ring lasers incorporating scanning filters. However, several unique operational characteristics of these lasers have not been adequately explained, and the lack of an accurate model has hindered optimization. We numerically investigated the characteristics of these sources, using a semiconductor optical amplifier (SOA) traveling-wave Langevin model, and found good agreement with experimental measurements. In particular, we explored the role of the SOA refractive-index nonlinearities in determining the intracavity frequency-shift-broadening and the emitted power dependence on scan speed and direction. Our model predicts both continuous-wave and pulse operation and shows a universal relationship between the output power of lasers that have different cavity lengths and the filter peak frequency shift per round trip, therefore revealing the advantage of short cavities for high-speed biomedical imaging.

  20. Anomalous-hydrodynamic analysis of charge-dependent elliptic flow in heavy-ion collisions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hongo, Masaru; Hirono, Yuji; Hirano, Tetsufumi

    Anomalous hydrodynamics is a low-energy effective theory that captures effects of quantum anomalies. We develop a numerical code of anomalous hydrodynamics and apply it to dynamics of heavy-ion collisions, where anomalous transports are expected to occur. This is the first attempt to perform fully non-linear numerical simulations of anomalous hydrodynamics. We discuss implications of the simulations for possible experimental observations of anomalous transport effects. From analyses of the charge-dependent elliptic flow parameters (vmore » $$±\\atop{2}$$) as a function of the net charge asymmetry A ±, we find that the linear dependence of Δv$$±\\atop{2}$$ ≡ v$$-\\atop{2}$$ - v$$+\\atop{2}$$ on the net charge asymmetry A ± cannot be regarded as a robust signal of anomalous transports, contrary to previous studies. We, however, find that the intercept Δv$$±\\atop{2}$$ (A ± = 0) is sensitive to anomalous transport effects.« less

  1. Anomalous-hydrodynamic analysis of charge-dependent elliptic flow in heavy-ion collisions

    DOE PAGES

    Hongo, Masaru; Hirono, Yuji; Hirano, Tetsufumi

    2017-12-10

    Anomalous hydrodynamics is a low-energy effective theory that captures effects of quantum anomalies. We develop a numerical code of anomalous hydrodynamics and apply it to dynamics of heavy-ion collisions, where anomalous transports are expected to occur. This is the first attempt to perform fully non-linear numerical simulations of anomalous hydrodynamics. We discuss implications of the simulations for possible experimental observations of anomalous transport effects. From analyses of the charge-dependent elliptic flow parameters (vmore » $$±\\atop{2}$$) as a function of the net charge asymmetry A ±, we find that the linear dependence of Δv$$±\\atop{2}$$ ≡ v$$-\\atop{2}$$ - v$$+\\atop{2}$$ on the net charge asymmetry A ± cannot be regarded as a robust signal of anomalous transports, contrary to previous studies. We, however, find that the intercept Δv$$±\\atop{2}$$ (A ± = 0) is sensitive to anomalous transport effects.« less

  2. Investigation of 2-Dimensional Isotropy of Under-Ice Roughness in the Beaufort Gyre and Implications for Mixed Layer Ocean Turbulence

    DTIC Science & Technology

    2008-03-01

    this roughness is important for numerical modeling and prediction of the Arctic air-ice-ocean system, which will play a significant role as the US Navy...is important for numerical modeling and prediction of the Arctic air-ice-ocean system, which will play a significant role as the US Navy increases... Model 1 is based on a sequence of plane parallel layers each with a constant gradient whereas Model 2 is based on a series of flat layers of

  3. Numerical Study on Stress Heterogeneity Development in Two-Phase Rocks with Large Rheological Contrast and Implications in the Lower Crust

    NASA Astrophysics Data System (ADS)

    Xu, Junshan; Zhang, Baohua

    2018-03-01

    Development of stress heterogeneity in two-phase rocks was investigated via a finite element method at 1000-1200 K and 100 MPa. Two groups of rock models were considered: anorthite-diopside and anorthite-clinopyroxene, with a phase volume ratio of 1:1 in each group and different dislocation creep rates between phases ( 4-8 orders of magnitude). Our numerical results indicate that the stress inside the model can be several times higher than the differential stress applied to the model and stress will tend to concentrate in hard phase, especially near the sharp boundaries with soft phase. Moreover, large stress gradient in hard phase and nearly homogeneous stress in soft phase will lead to the initialization of localized dynamic recrystallization or fracture. These numerical observations suggest that the rheological contrast between two phases plays a crucial role in stress heterogeneity rather than other factors (such as grain size, the boundary conditions or mesh density), which may eventually accelerate development of stress heterogeneity in the lower crust. Our study provides new insights into the dynamic processes of grain size reduction in the lower crust, which may cause the transformation from dislocation creep to diffusion creep and enable the weakened shear zones.

  4. The cultural implications of growth: Modeling nonlinear interaction of trait selection and population dynamics

    NASA Astrophysics Data System (ADS)

    Antoci, Angelo; Galeotti, Marcello; Russu, Paolo; Luigi Sacco, Pier

    2018-05-01

    In this paper, we study a nonlinear model of the interaction between trait selection and population dynamics, building on previous work of Ghirlanda et al. [Theor. Popul. Biol. 77, 181-188 (2010)] and Antoci et al. [Commun. Nonlinear Sci. Numer. Simul. 58, 92-106 (2018)]. We establish some basic properties of the model dynamics and present some simulations of the fine-grained structure of alternative dynamic regimes for chosen combinations of parameters. The role of the parameters that govern the reinforcement/corruption of maladaptive vs. adaptive traits is of special importance in determining the model's dynamic evolution. The main implication of this result is the need to pay special attention to the structural forces that may favor the emergence and consolidation of maladaptive traits in contemporary socio-economies, as it is the case, for example, for the stimulation of dysfunctional consumption habits and lifestyles in the pursuit of short-term profits.

  5. The Dark Side of Forgiveness: The Tendency to Forgive Predicts Continued Psychological and Physical Aggression in Marriage

    PubMed Central

    McNulty, James K.

    2014-01-01

    Despite a burgeoning literature that documents numerous positive implications of forgiveness, scholars know very little about the potential negative implications of forgiveness. In particular, the tendency to express forgiveness may lead offenders to feel free to offend again by removing unwanted consequences for their behavior (e.g., anger, criticism, rejection, loneliness) that would otherwise discourage reoffending. Consistent with this possibility, the current longitudinal study of newlywed couples revealed a positive association between spouses’ reports of their tendencies to express forgiveness to their partners and those partners’ reports of psychological and physical aggression. Specifically, although spouses who reported being relatively more forgiving experienced psychological and physical aggression that remained stable over the first 4 years of marriage, spouses who reported being relatively less forgiving experienced declines in both forms of aggression over time. These findings join just a few others in demonstrating that forgiveness is not a panacea. PMID:21558557

  6. The cultural implications of growth: Modeling nonlinear interaction of trait selection and population dynamics.

    PubMed

    Antoci, Angelo; Galeotti, Marcello; Russu, Paolo; Luigi Sacco, Pier

    2018-05-01

    In this paper, we study a nonlinear model of the interaction between trait selection and population dynamics, building on previous work of Ghirlanda et al. [Theor. Popul. Biol. 77, 181-188 (2010)] and Antoci et al. [Commun. Nonlinear Sci. Numer. Simul. 58, 92-106 (2018)]. We establish some basic properties of the model dynamics and present some simulations of the fine-grained structure of alternative dynamic regimes for chosen combinations of parameters. The role of the parameters that govern the reinforcement/corruption of maladaptive vs. adaptive traits is of special importance in determining the model's dynamic evolution. The main implication of this result is the need to pay special attention to the structural forces that may favor the emergence and consolidation of maladaptive traits in contemporary socio-economies, as it is the case, for example, for the stimulation of dysfunctional consumption habits and lifestyles in the pursuit of short-term profits.

  7. Protecting Adolescents' Right to Seek Treatment for Sexually Transmitted Diseases without Parental Consent: The Arizona Experience with Senate Bill 1309

    PubMed Central

    Goodwin, Kimberly D.; Taylor, Melanie M.; Brown, Erin C. Fuse; Winscott, Michelle; Scanlon, Megan; Hodge, James G.; Mickey, Tom; England, Bob

    2012-01-01

    In 2010, Senate Bill 1309 included language to repeal an existing Arizona law that enables minors younger than 18 years of age to seek diagnosis and treatment of sexually transmitted diseases (STDs) without parental consent. Numerous implications were identified that would have stemmed from parental consent provisions originally proffered in Senate Bill 1309. These implications included diminished access to essential health services among minors, exacerbated existing health disparities, increased health-care spending costs, and thwarted efforts to curb the spread of STDs. Lastly, minors would have been deprived of existing privacy protections concerning their STD-related medical information. This case study describes how collaborative advocacy efforts resulted in the successful amendment of Senate Bill 1309 to avert the negative sexual and reproductive health outcomes among adolescents stemming from the potential repeal of their existing legal right to seek STD treatment without parental consent. PMID:22547855

  8. Protecting adolescents' right to seek treatment for sexually transmitted diseases without parental consent: the Arizona experience with Senate Bill 1309.

    PubMed

    Goodwin, Kimberly D; Taylor, Melanie M; Brown, Erin C Fuse; Winscott, Michelle; Scanlon, Megan; Hodge, James G; Mickey, Tom; England, Bob

    2012-01-01

    In 2010, Senate Bill 1309 included language to repeal an existing Arizona law that enables minors younger than 18 years of age to seek diagnosis and treatment of sexually transmitted diseases (STDs) without parental consent. Numerous implications were identified that would have stemmed from parental consent provisions originally proffered in Senate Bill 1309. These implications included diminished access to essential health services among minors, exacerbated existing health disparities, increased health-care spending costs, and thwarted efforts to curb the spread of STDs. Lastly, minors would have been deprived of existing privacy protections concerning their STD-related medical information. This case study describes how collaborative advocacy efforts resulted in the successful amendment of Senate Bill 1309 to avert the negative sexual and reproductive health outcomes among adolescents stemming from the potential repeal of their existing legal right to seek STD treatment without parental consent.

  9. On the status of knowledge for using punishment implications for treating behavior disorders.

    PubMed Central

    Lerman, Dorothea C; Vorndran, Christina M

    2002-01-01

    In this paper, we review basic and applied findings on punishment and discuss the importance of conducting further research in this area. The characteristics of responding during punishment and numerous factors that interact with basic processes are delineated in conjunction with implications for the treatment of behavior disorders in clinical populations. We conclude that further understanding of punishment processes is needed to develop a highly systematic, effective technology of behavior change, including strategies for improving the efficacy of less intrusive procedures and for successfully fading treatment. PMID:12555918

  10. Skull Flexure from Blast Waves: A Mechanism for Brain Injury with Implications for Helmet Design

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moss, W C; King, M J; Blackman, E G

    2009-04-30

    Traumatic brain injury [TBI] has become a signature injury of current military conflicts, with debilitating, costly, and long-lasting effects. Although mechanisms by which head impacts cause TBI have been well-researched, the mechanisms by which blasts cause TBI are not understood. From numerical hydrodynamic simulations, we have discovered that non-lethal blasts can induce sufficient skull flexure to generate potentially damaging loads in the brain, even without a head impact. The possibility that this mechanism may contribute to TBI has implications for injury diagnosis and armor design.

  11. The language of uncertainty in genetic risk communication: framing and verbal versus numerical information.

    PubMed

    Welkenhuysen, M; Evers-Kiebooms, G; d'Ydewalle, G

    2001-05-01

    Within a group of 300 medical students, two characteristics of risk communication in the context of a decision regarding prenatal diagnosis for cystic fibrosis are manipulated: verbal versus numerical probabilities and the negative versus positive framing of the problem (having a child with versus without cystic fibrosis). Independently of the manipulations, most students were in favor of prenatal diagnosis. The effect of framing was only significant in the conditions with verbal information: negative framing produced a stronger choice in favor of prenatal diagnosis than positive framing. The framing effect in the verbal conditions and its absence in the numerical conditions are explained by the dominance of the problem-occurrence orientation in health matters as well as a recoding process which is more likely to occur in the numerical (the probability "1-P" switches to its counterpart "P") than in the verbal conditions. The implications for the practice of genetic counseling are discussed.

  12. Heading in football. Part 3: Effect of ball properties on head response

    PubMed Central

    Shewchenko, N; Withnall, C; Keown, M; Gittens, R; Dvorak, J

    2005-01-01

    Objectives: Head impacts from footballs are an essential part of the game but have been implicated in mild and acute neuropsychological impairment. Ball characteristics have been noted in literature to affect the impact response of the head; however, the biomechanics are not well understood. The present study determined whether ball mass, pressure, and construction characteristics help reduce head and neck can impact response. Methods: Head responses under ball impact (6–7 m/s) were measured with a biofidelic numerical human model and controlled human subject trials (n = 3). Three ball masses and four ball pressures were investigated for frontal heading. Further, the effect of ball construction in wet/dry conditions was studied with the numerical model. The dynamic ball characteristics were determined experimentally. Head linear and angular accelerations were measured and compared with injury assessment functions comprising peak values and head impact power. Neck responses were assessed with the numerical model. Results: Ball mass reductions up to 35% resulted in decreased head responses up to 23–35% for the numerical and subject trials. Similar decreases in neck axial and shear responses were observed. Ball pressure reductions of 50% resulted in head and neck response reductions up to 10–31% for the subject trials and numerical model. Head response reductions up to 15% were observed between different ball constructions. The wet condition generally resulted in greater head and neck responses of up to 20%. Conclusion: Ball mass, pressure, and construction can reduce the impact severity to the head and neck. It is foreseeable that the benefits can be extended to players of all ages and skill levels. PMID:16046354

  13. Aeroacoustics of Turbulent High-Speed Jets

    NASA Technical Reports Server (NTRS)

    Rao, Ram Mohan; Lundgren, Thomas S.

    1996-01-01

    Aeroacoustic noise generation in a supersonic round jet is studied to understand in particular the effect of turbulence structure on the noise without numerically compromising the turbulence itself. This means that direct numerical simulations (DNS's) are needed. In order to use DNS at high enough Reynolds numbers to get sufficient turbulence structure we have decided to solve the temporal jet problem, using periodicity in the direction of the jet axis. Physically this means that turbulent structures in the jet are repeated in successive downstream cells instead of being gradually modified downstream into a jet plume. Therefore in order to answer some questions about the turbulence we will partially compromise the overall structure of the jet. The first section of chapter 1 describes some work on the linear stability of a supersonic round jet and the implications of this for the jet noise problem. In the second section we present preliminary work done using a TVD numerical scheme on a CM5. This work is only two-dimensional (plane) but shows very interesting results, including weak shock waves. However this is a nonviscous computation and the method resolves the shocks by adding extra numerical dissipation where the gradients are large. One wonders whether the extra dissipation would influence small turbulent structures like small intense vortices. The second chapter is an extensive discussion of preliminary numerical work using the spectral method to solve the compressible Navier-Stokes equations to study turbulent jet flows. The method uses Fourier expansions in the azimuthal and streamwise direction and a 1-D B-spline basis representation in the radial direction. The B-spline basis is locally supported and this ensures block diagonal matrix equations which are solved in O(N) steps. A very accurate highly resolved DNS of a turbulent jet flow is expected.

  14. A Graph is Worth a Thousand Words: How Overconfidence and Graphical Disclosure of Numerical Information Influence Financial Analysts Accuracy on Decision Making

    PubMed Central

    Leite, Rodrigo Oliveira; de Aquino, André Carlos Busanelli

    2016-01-01

    Previous researches support that graphs are relevant decision aids to tasks related to the interpretation of numerical information. Moreover, literature shows that different types of graphical information can help or harm the accuracy on decision making of accountants and financial analysts. We conducted a 4×2 mixed-design experiment to examine the effects of numerical information disclosure on financial analysts’ accuracy, and investigated the role of overconfidence in decision making. Results show that compared to text, column graph enhanced accuracy on decision making, followed by line graphs. No difference was found between table and textual disclosure. Overconfidence harmed accuracy, and both genders behaved overconfidently. Additionally, the type of disclosure (text, table, line graph and column graph) did not affect the overconfidence of individuals, providing evidence that overconfidence is a personal trait. This study makes three contributions. First, it provides evidence from a larger sample size (295) of financial analysts instead of a smaller sample size of students that graphs are relevant decision aids to tasks related to the interpretation of numerical information. Second, it uses the text as a baseline comparison to test how different ways of information disclosure (line and column graphs, and tables) can enhance understandability of information. Third, it brings an internal factor to this process: overconfidence, a personal trait that harms the decision-making process of individuals. At the end of this paper several research paths are highlighted to further study the effect of internal factors (personal traits) on financial analysts’ accuracy on decision making regarding numerical information presented in a graphical form. In addition, we offer suggestions concerning some practical implications for professional accountants, auditors, financial analysts and standard setters. PMID:27508519

  15. Numerical modelling as a cost-reduction tool for probability of detection of bolt hole eddy current testing

    NASA Astrophysics Data System (ADS)

    Mandache, C.; Khan, M.; Fahr, A.; Yanishevsky, M.

    2011-03-01

    Probability of detection (PoD) studies are broadly used to determine the reliability of specific nondestructive inspection procedures, as well as to provide data for damage tolerance life estimations and calculation of inspection intervals for critical components. They require inspections on a large set of samples, a fact that makes these statistical assessments time- and cost-consuming. Physics-based numerical simulations of nondestructive testing inspections could be used as a cost-effective alternative to empirical investigations. They realistically predict the inspection outputs as functions of the input characteristics related to the test piece, transducer and instrument settings, which are subsequently used to partially substitute and/or complement inspection data in PoD analysis. This work focuses on the numerical modelling aspects of eddy current testing for the bolt hole inspections of wing box structures typical of the Lockheed Martin C-130 Hercules and P-3 Orion aircraft, found in the air force inventory of many countries. Boundary element-based numerical modelling software was employed to predict the eddy current signal responses when varying inspection parameters related to probe characteristics, crack geometry and test piece properties. Two demonstrator exercises were used for eddy current signal prediction when lowering the driver probe frequency and changing the material's electrical conductivity, followed by subsequent discussions and examination of the implications on using simulated data in the PoD analysis. Despite some simplifying assumptions, the modelled eddy current signals were found to provide similar results to the actual inspections. It is concluded that physics-based numerical simulations have the potential to partially substitute or complement inspection data required for PoD studies, reducing the cost, time, effort and resources necessary for a full empirical PoD assessment.

  16. A Graph is Worth a Thousand Words: How Overconfidence and Graphical Disclosure of Numerical Information Influence Financial Analysts Accuracy on Decision Making.

    PubMed

    Cardoso, Ricardo Lopes; Leite, Rodrigo Oliveira; de Aquino, André Carlos Busanelli

    2016-01-01

    Previous researches support that graphs are relevant decision aids to tasks related to the interpretation of numerical information. Moreover, literature shows that different types of graphical information can help or harm the accuracy on decision making of accountants and financial analysts. We conducted a 4×2 mixed-design experiment to examine the effects of numerical information disclosure on financial analysts' accuracy, and investigated the role of overconfidence in decision making. Results show that compared to text, column graph enhanced accuracy on decision making, followed by line graphs. No difference was found between table and textual disclosure. Overconfidence harmed accuracy, and both genders behaved overconfidently. Additionally, the type of disclosure (text, table, line graph and column graph) did not affect the overconfidence of individuals, providing evidence that overconfidence is a personal trait. This study makes three contributions. First, it provides evidence from a larger sample size (295) of financial analysts instead of a smaller sample size of students that graphs are relevant decision aids to tasks related to the interpretation of numerical information. Second, it uses the text as a baseline comparison to test how different ways of information disclosure (line and column graphs, and tables) can enhance understandability of information. Third, it brings an internal factor to this process: overconfidence, a personal trait that harms the decision-making process of individuals. At the end of this paper several research paths are highlighted to further study the effect of internal factors (personal traits) on financial analysts' accuracy on decision making regarding numerical information presented in a graphical form. In addition, we offer suggestions concerning some practical implications for professional accountants, auditors, financial analysts and standard setters.

  17. Wettability effect on capillary trapping of supercritical CO2 at pore-scale: micromodel experiment and numerical modeling

    NASA Astrophysics Data System (ADS)

    Hu, R.; Wan, J.

    2015-12-01

    Wettability of reservoir minerals along pore surfaces plays a controlling role in capillary trapping of supercritical (sc) CO2 in geologic carbon sequestration. The mechanisms controlling scCO2 residual trapping are still not fully understood. We studied the effect of pore surface wettability on CO2 residual saturation at the pore-scale using engineered high pressure and high temperature micromodel (transparent pore networks) experiments and numerical modeling. Through chemical treatment of the micromodel pore surfaces, water-wet, intermediate-wet, and CO2-wet micromodels can be obtained. Both drainage and imbibition experiments were conducted at 8.5 MPa and 45 °C with controlled flow rate. Dynamic images of fluid-fluid displacement processes were recorded using a microscope with a CCD camera. Residual saturations were determined by analysis of late stage imbibition images of flow path structures. We performed direct numerical simulations of the full Navier-Stokes equations using a volume-of-fluid based finite-volume framework for the primary drainage and the followed imbibition for the micromodel experiments with different contact angles. The numerical simulations agreed well with our experimental observations. We found that more scCO2 can be trapped within the CO2-wet micromodel whereas lower residual scCO2 saturation occurred within the water-wet micromodels in both our experiments and the numerical simulations. These results provide direct and consistent evidence of the effect of wettability, and have important implications for scCO2 trapping in geologic carbon sequestration.

  18. Switchgrass Genetics: Status, Future Directions, and Implications for Simulations

    USDA-ARS?s Scientific Manuscript database

    Switchgrass (Panicum virgatum L.) is a C4 polymorphic species with two ploidy levels, two major and numerous minor ecotypes adapted to different plant hardiness zones and ecoregions in its range. Switchgrasses are determinate, photoperiod sensitive, and require short days to induce flowering. Photo...

  19. National Security Implications of Global Warming Policy

    DTIC Science & Technology

    2010-03-01

    Although numerous historical examples demonstrate how actual climate change has contributed to the rise and fall of powers, global warming , in and of...become convinced that global warming is universally bad and humans are the primary cause, political leaders may develop ill-advised policies restricting

  20. Economic implications of implant selection.

    PubMed

    DeFronzo, D J; Landsman, A S; Ghareeb, J A

    1995-07-01

    Numerous types of implantable biomaterials are available for a variety of applications. Although much has been written about the physical properties or biocompatibility issues, very few papers have focused on the economic feasibility of these materials. This article assesses financial factors associated with first metatarsophalangeal total joint prostheses.

  1. [Symptoms diagnosis and treatment of dyscalulia].

    PubMed

    Ise, Elena; Schulte-Körne, Gerd

    2013-07-01

    Children with dyscalculia show deficits in basic numerical processing which cause difficulties in the acquisition of mathematical skills. This article provides an overview of current research findings regarding the symptoms, cause, and prognosis of dyscalculia, and it summarizes recent developments in the diagnosis, early intervention, and treatment thereof. Diagnosis has improved recently because newly developed tests focus not only on the math curriculum, but also on basic skills found to be impaired in dyscalculia. A controversial debate continues with regard to IQ achievement discrepancy. International studies have demonstrated the effectiveness of specialized interventions. This article summarizes the research findings from intervention studies, describes different treatment approaches, and discusses implications for clinical practice.

  2. Environmental exposures to metals in Native communities and implications for child development: basis for the Navajo birth cohort study.

    PubMed

    Lewis, Johnnye; Gonzales, Melissa; Burnette, Courtney; Benally, Malcolm; Seanez, Paula; Shuey, Christopher; Nez, Helen; Nez, Christopher; Nez, Seraphina

    2015-01-01

    Two disparate statistics often cited for the Western United States raise concern about risks for developmental disabilities in Native American children. First, 13 of the states with the highest percentage of Native American population are located in the Western United States (U.S. Census Bureau, 2012 ). Second, more than 161,000 abandoned hard-rock mines are located in 12 Western states (General Accounting Office, 2014 ). Moreover, numerous studies have linked low-level metals exposure with birth defects and developmental delays. Concern has emerged among tribal populations that metals exposure from abandoned mines might threaten development of future generations.

  3. Considerations in pharmaceutical conversion: focus on antihistamines.

    PubMed

    Garbus, S B; Moulton, B W; Meltzer, E O; Reich, P R; Weinreb, L F; Friedman, J A; Orland, B I

    1997-04-01

    The practice of pharmaceutical conversion, which encompasses three types of drug interchange (generic, brand, and therapeutic substitution), is increasing in managed care settings. Pharmaceutical conversion has numerous implications for managed care organizations, their healthcare providers, and their customers. Although drug cost may be a driving consideration in pharmaceutical conversion, a number of other considerations are of equal or greater importance in the decision-making process may affect the overall cost of patient care. Among these considerations are clinical, psychosocial, and safety issues; patient adherence; patient satisfaction; and legal implications of pharmaceutical conversion. Patient-centered care must always remain central to decisions about pharmaceutical conversion. This article discusses the issues related to, and implications of, pharmaceutical conversion utilizing the antihistamines class of drugs as the case situation.

  4. Water Cycle Implications of Agriculture and Flood Control Infrastructure in the San Francisco Bay-Delta System

    NASA Astrophysics Data System (ADS)

    MacVean, L. J.; Thompson, S. E.; Sivapalan, M.; Hutton, P.

    2016-12-01

    California's Sacramento-San Joaquin Delta sits at the intersection of vast agricultural and population centers, and supplies fresh water for the diverse and often competing needs of ecosystems, farmers, and millions of Californians. In this study, we address the question of how flows into and out of the Delta have evolved in response to human intervention since 1850 in order to augment the scientific foundation of management decisions. In particular, we have developed a numerical model to quantify Delta outflows over the last 165 years, through which we explore the implications of the conversion of native vegetation to agricultural crops and the construction of flood control infrastructure. Our model domain encompasses the watersheds tributary to the San Francisco Bay-Delta system, and simulates the dynamic components of water usage through vegetative uptake and evapotranspiration, groundwater recharge, flood conveyance, and water exports at incremental levels of development from 1850 to the present. The model is run using historical climatological forcing; the climate and the effects of development on the Delta's watersheds are allowed to co-evolve. After verification that the dominant processes are captured in the numerics, the results illustrate the interactions between soil water storage, flood water stored behind levees, and consumption of water through ET and groundwater recharge, and their effects on the inflows to the San Francisco Bay estuary. Our study provides a picture of the changes in magnitude and temporal distribution of freshwater flows brought about by both intentional and unintentional consequences of the development of California's Central Valley.

  5. Using biological endpoints for assessing exposures to endocrine disrupting contaminants of emerging concern

    EPA Science Inventory

    Most of what is known about the implications of endocrine disrupting chemicals (EDCs) in the environment is site- or compound-specific. There are numerous reports of gonadal histological abnormalities, alterations in sex ratios, and high vitellogenin protein levels in fish below ...

  6. Susceptibility based upon Chemical Interaction with Disease Processes: Potential Implications for Risk Assessment

    EPA Science Inventory

    One of the challenges facing toxicology and risk assessment is that numerous host and environmental factors may modulate vulnerability and risk. An area of increasing interest is the potential for chemicals to interact with background aging and disease processes, an interaction...

  7. Faith-Based Human Services Initiatives: Considerations for Social Work Practice and Theory

    ERIC Educational Resources Information Center

    Tangenberg, Kathleen M.

    2005-01-01

    Faith-based human services initiatives present numerous challenges to professional social work. This article explores ways a theoretical integration of ecosystems and structuration perspectives may help social workers navigate complex ideological and practical implications of changing service delivery policies. The article highlights diversity…

  8. 76 FR 25409 - Privacy Act of 1974

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... Medicare beneficiaries from CMS databases including: health care usage, demographic, enrollment, and survey... and timely assess the current health care usage by the patient population served by VA, to forecast..., and to understand the numerous implications of cross-usage between VA and non-VA health care systems...

  9. Designing Instruction in the Face of Technology Transience

    ERIC Educational Resources Information Center

    Linder-VanBerschot, Jennifer A.; Summers, Laura L.

    2015-01-01

    As we strive to provide quality and sustainable online learning experiences, we must frame instructional design decisions around learners' current needs and interaction with technology. This article explores the implications of technology transience on instructional design. We provide numerous examples of programs assuming a purposeful approach to…

  10. Nitrogen Control Through Decentralized Wastewater Treatment: Process Performance and Alternative Management Strategies

    EPA Science Inventory

    Decentralized or onsite wastewater treatment (OWT) systems have long been implicated in being a major source of N inputs to surface and ground waters and numerous regulatory bodies have promulgated strict total N (TN) effluent standards in N-sensitive areas. These standards, howe...

  11. Brain stimulation, mathematical, and numerical training: Contribution of core and noncore skills.

    PubMed

    Looi, C Y; Cohen Kadosh, R

    2016-01-01

    Mathematical abilities that are correlated with various life outcomes vary across individuals. One approach to improve mathematical abilities is by understanding the underlying cognitive functions. Theoretical and experimental evidence suggest that mathematical abilities are subserved by "core" and "noncore" skills. Core skills are commonly regarded as the "innate" capacity to attend to and process numerical information, while noncore skills are those that are important for mathematical cognition, but are not exclusive to the mathematical domain such as executive functions, spatial skills, and attention. In recent years, mathematical training has been combined with the application of noninvasive brain stimulation to further enhance training outcomes. However, the development of more strategic training paradigms is hindered by the lack of understanding on the contributory nature of core and noncore skills and their neural underpinnings. In the current review, we will examine the effects of brain stimulation with focus on transcranial electrical stimulation on core and noncore skills, and its impact on mathematical and numerical training. We will conclude with a discussion on the theoretical and experimental implications of these studies and directions for further research. © 2016 Elsevier B.V. All rights reserved.

  12. Capital Outlay as an Educational Equity Issue: A Review of Educational Research and Legal Opinion.

    ERIC Educational Resources Information Center

    Thompson, David C.; And Others

    1989-01-01

    Examines issues of how school districts finance facility needs. Reviews numerous recent legal decisions addressing capital outlay; discusses implications for educational policymakers. Concludes that court proceedings and research literature suggest an important association between wealth dependency and unmet needs in funding school district…

  13. Ethical Issues in School Art Therapy

    ERIC Educational Resources Information Center

    Moriya, Dafna

    2006-01-01

    School art therapists face numerous ethical dilemmas, from referrals to therapy, through privacy, safety and predictability in the art therapy room, to the need to balance cooperation with the educational staff and its expectations of shared information with loyalty to the patient. Breach of confidentiality also has legal implications. The…

  14. Coordinating Units at the Candy Depot

    ERIC Educational Resources Information Center

    Norton, Anderson; Boyce, Steven; Hatch, Jennifer

    2015-01-01

    In general, units coordination refers to the relationships that students can maintain between various units when working within a numerical situation. It is critical that middle school students learn to coordinate three levels of units not only because of their importance in understanding fractions but also because of their implications for…

  15. Fetal programming and environmental exposures: Implications for prenatal care and preterm birth

    EPA Science Inventory

    Fetal programming is an enormously complex process that relies on numerous environmental inputs from uterine tissue, the placenta, the maternal blood supply, and other sources. Recent evidence has made clear that the process is not based entirely on genetics, but rather on a deli...

  16. Organization of a resistance gene cluster linked to rhizomania resistance in sugar beet

    USDA-ARS?s Scientific Manuscript database

    Genetic resistance to rhizomania has been in use for over 40 years. Characterization of the molecular basis for susceptibility and resistance has proved challenging. Nucleotide-binding leucine-rich-repeat-containing (NB-LRR) genes have been implicated in numerous gene-for-gene resistance interaction...

  17. Examining Substance Abuse in Truant Youths and Their Caregivers: Implications for Truancy Intervention

    ERIC Educational Resources Information Center

    Flaherty, Christopher W.; Sutphen, Richard D.; Ely, Gretchen E.

    2012-01-01

    Truancy is associated with an array of negative social consequences, including poor school performance, delinquency, and dropout. Numerous individual, family, school, and community risk factors associated with truancy are also associated with adolescent substance abuse. However, little is known about substance use patterns among court-adjudicated…

  18. High-Stakes Educational Testing and Democracy--Antagonistic or Symbiotic Relationship?

    ERIC Educational Resources Information Center

    Ydesen, Christian

    2014-01-01

    This article argues that high-stakes educational testing, along with the attendant questions of power, education access, education management and social selection, cannot be considered in isolation from society at large. Thus, high-stakes testing practices bear numerous implications for democratic conditions in society. For decades, advocates of…

  19. Modeling Uncertainty and Its Implications in Complex Interdependent Networks

    DTIC Science & Technology

    2016-04-30

    observables chosen evolve dynamically (i.e., change over time); also, it is absolutely NECESSARY for these to be numerical, or to correspond to some sort ...ascertain the quantitative mechanism for color transitions of the red, yellow, or green bubbles that capture the changes in value of Cost, Schedule

  20. Influences of Television on Children's Behavior: Implications for War and Peace.

    ERIC Educational Resources Information Center

    Frost, Joe L.

    Television is robbing children of their childhood. Moreover, it is destroying children's developing symbolic processes, and inhibiting their creativity and play. Television has remarkable influence over children's behavior. At this point, it is plausible to hypothesize linkages between television viewing and numerous social problems involving…

  1. Numerical simulation of coupled electrochemical and transport processes in battery systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liaw, B.Y.; Gu, W.B.; Wang, C.Y.

    1997-12-31

    Advanced numerical modeling to simulate dynamic battery performance characteristics for several types of advanced batteries is being conducted using computational fluid dynamics (CFD) techniques. The CFD techniques provide efficient algorithms to solve a large set of highly nonlinear partial differential equations that represent the complex battery behavior governed by coupled electrochemical reactions and transport processes. The authors have recently successfully applied such techniques to model advanced lead-acid, Ni-Cd and Ni-MH cells. In this paper, the authors briefly discuss how the governing equations were numerically implemented, show some preliminary modeling results, and compare them with other modeling or experimental data reportedmore » in the literature. The authors describe the advantages and implications of using the CFD techniques and their capabilities in future battery applications.« less

  2. Direct numerical simulation of a high Ka CH 4/air stratified premixed jet flame

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Haiou; Hawkes, Evatt R.; Savard, Bruno

    Here, direct numerical simulation (DNS) of a high Karlovitz number (Ka) CH 4/air stratified premixed jet flame was performed and used to provide insights into fundamentals of turbulent stratified premixed flames and their modelling implications. The flame exhibits significant stratification where the central jet has an equivalence ratio of 0.4, which is surrounded by a pilot flame with an equivalence ratio of 0.9. A reduced chemical mechanism for CH 4/air combustion based on GRI-Mech3.0 was used, including 268 elementary reactions and 28 transported species.

  3. A Family of Poisson Processes for Use in Stochastic Models of Precipitation

    NASA Astrophysics Data System (ADS)

    Penland, C.

    2013-12-01

    Both modified Poisson processes and compound Poisson processes can be relevant to stochastic parameterization of precipitation. This presentation compares the dynamical properties of these systems and discusses the physical situations in which each might be appropriate. If the parameters describing either class of systems originate in hydrodynamics, then proper consideration of stochastic calculus is required during numerical implementation of the parameterization. It is shown here that an improper numerical treatment can have severe implications for estimating rainfall distributions, particularly in the tails of the distributions and, thus, on the frequency of extreme events.

  4. Connecting Numerical Relativity and Data Analysis of Gravitational Wave Detectors

    NASA Astrophysics Data System (ADS)

    Shoemaker, Deirdre; Jani, Karan; London, Lionel; Pekowsky, Larne

    Gravitational waves deliver information in exquisite detail about astrophysical phenomena, among them the collision of two black holes, a system completely invisible to the eyes of electromagnetic telescopes. Models that predict gravitational wave signals from likely sources are crucial for the success of this endeavor. Modeling binary black hole sources of gravitational radiation requires solving the Einstein equations of General Relativity using powerful computer hardware and sophisticated numerical algorithms. This proceeding presents where we are in understanding ground-based gravitational waves resulting from the merger of black holes and the implications of these sources for the advent of gravitational-wave astronomy.

  5. Direct numerical simulation of a high Ka CH 4/air stratified premixed jet flame

    DOE PAGES

    Wang, Haiou; Hawkes, Evatt R.; Savard, Bruno; ...

    2018-04-24

    Here, direct numerical simulation (DNS) of a high Karlovitz number (Ka) CH 4/air stratified premixed jet flame was performed and used to provide insights into fundamentals of turbulent stratified premixed flames and their modelling implications. The flame exhibits significant stratification where the central jet has an equivalence ratio of 0.4, which is surrounded by a pilot flame with an equivalence ratio of 0.9. A reduced chemical mechanism for CH 4/air combustion based on GRI-Mech3.0 was used, including 268 elementary reactions and 28 transported species.

  6. Mucosal immunity in HIV controllers: the right place at the right time.

    PubMed

    Shacklett, Barbara L; Ferre, April L

    2011-05-01

    The phenomenon of long-term nonprogression in HIV infection has been recognized for some time, and the ability of rare individuals, designated 'elite controllers', to control HIV in the absence of therapy is the focus of numerous ongoing studies. This review focuses on studies of HIV-specific immune responses in mucosal tissues as a potential correlate of immune control, with an emphasis on recently published work. Genetic studies have implicated a role for elements localized to the major histocompatibility complex (MHC) on chromosome 6 in the immune control of HIV infection. In parallel, functional studies have strongly implicated MHC class I-restricted, CD8+ T-cell responses as a major contributor to elite control. In addition, the localization of HIV-specific CD8+ and CD4+ T cells with respect to the major sites of virus replication in the body may be critical in determining clinical outcome. Recent findings suggest that MHC class I-restricted, CD8+ T cells are a major component of immune control in 'elite controllers'. In addition, the presence of these effector cells at or near critical viral reservoirs, such as mucosal tissues, may be critical in determining their effectiveness at limiting viral replication and dissemination.

  7. Genomic and Epigenomic Aberrations in Esophageal Squamous Cell Carcinoma and Implications for Patients

    PubMed Central

    Lin, De-Chen; Wang, Ming-Rong; Koeffler, H. Phillip

    2018-01-01

    Esophageal squamous cell carcinoma (ESCC) is a common malignancy without effective therapy. The exomes of more than 600 ESCCs have been sequenced in the past 4 years, and numerous key aberrations have been identified. Recently, researchers reported both inter- and intratumor heterogeneity. Although these are interesting observations, their clinical implications are unclear due to the limited number of samples profiled. Epigenomic alterations, such as changes in DNA methylation, histone acetylation, and RNA editing, also have been observed in ESCCs. However, it is not clear what proportion of ESCC cells carry these epigenomic aberrations or how they contribute to tumor development. We review the genomic and epigenomic characteristics of ESCCs, with a focus on emerging themes. We discuss their clinical implications and future research directions. PMID:28757263

  8. Extending the construct of psychopathy to youth: implications for understanding, diagnosing, and treating antisocial children and adolescents.

    PubMed

    Frick, Paul J

    2009-12-01

    This paper reviews several attempts to extend the construct of psychopathy to children and adolescents. The research suggests that the presence of callous-unemotional (CU) traits may be particularly important. Specifically, the presence of these traits designates a clinically important subgroup of youth with childhood-onset conduct problems who show a particularly severe, aggressive, and stable pattern of antisocial behaviour. Also, children with CU traits show numerous emotional, cognitive, and personality features that are distinct from other antisocial youth that are similar to features found in adults with psychopathy. The research on CU traits has important implications for understanding the different causal pathways through which children develop severe antisocial and aggressive behaviour, as well as implications for diagnosing and intervening with antisocial youth.

  9. Eukaryotic Chemotaxis

    PubMed Central

    Rappel, Wouter-Jan; Loomis, William F.

    2009-01-01

    During eukaryotic chemotaxis, external chemical gradients guide the crawling motion of cells. This process plays an important role in a large variety of biological systems and has wide ranging medical implications. New experimental techniques including confocal microscopy and microfluidics have advanced our understanding of chemotaxis while numerical modeling efforts are beginning to offer critical insights. In this short review, we survey the current experimental status of the field by dividing chemotaxis into three distinct “modules”: directional sensing, polarity and motility. For each module, we attempt to point out potential new directions of research and discuss how modeling studies interact with experimental investigations. PMID:20648241

  10. Are Gasoline Prices a Factor in Residential Relocation Decisions? Preliminary Findings from the American Housing Survey, 1996–2008

    PubMed Central

    Chi, Guangqing; Boydstun, Jamie

    2018-01-01

    Residential relocation choice is affected by numerous factors, but gasoline prices as a potential factor have not been investigated. This study examines gasoline price changes and residential relocation choice using 1996–2008 American Housing Survey data. We found higher gasoline prices are associated with a higher percentage of movers choosing locations closer to workplaces. The findings have implications for addressing the impacts of volatile gasoline prices on land use planning and policies; resilient “smart cities or communities” are one possible solution. PMID:29658959

  11. Nonlocal response in plasmonic waveguiding with extreme light confinement

    NASA Astrophysics Data System (ADS)

    Toscano, Giuseppe; Raza, Søren; Yan, Wei; Jeppesen, Claus; Xiao, Sanshui; Wubs, Martijn; Jauho, Antti-Pekka; Bozhevolnyi, Sergey I.; Mortensen, N. Asger

    2013-07-01

    We present a novel wave equation for linearized plasmonic response, obtained by combining the coupled real-space differential equations for the electric field and current density. Nonlocal dynamics are fully accounted for, and the formulation is very well suited for numerical implementation, allowing us to study waveguides with subnanometer cross-sections exhibiting extreme light confinement. We show that groove and wedge waveguides have a fundamental lower limit in their mode confinement, only captured by the nonlocal theory. The limitation translates into an upper limit for the corresponding Purcell factors, and thus has important implications for quantum plasmonics.

  12. Heat and mass transfer in unsteady rotating fluid flow with binary chemical reaction and activation energy.

    PubMed

    Awad, Faiz G; Motsa, Sandile; Khumalo, Melusi

    2014-01-01

    In this study, the Spectral Relaxation Method (SRM) is used to solve the coupled highly nonlinear system of partial differential equations due to an unsteady flow over a stretching surface in an incompressible rotating viscous fluid in presence of binary chemical reaction and Arrhenius activation energy. The velocity, temperature and concentration distributions as well as the skin-friction, heat and mass transfer coefficients have been obtained and discussed for various physical parametric values. The numerical results obtained by (SRM) are then presented graphically and discussed to highlight the physical implications of the simulations.

  13. Hybridization of Guided Surface Acoustic Modes in Unconsolidated Granular Media by a Resonant Metasurface

    NASA Astrophysics Data System (ADS)

    Palermo, Antonio; Krödel, Sebastian; Matlack, Kathryn H.; Zaccherini, Rachele; Dertimanis, Vasilis K.; Chatzi, Eleni N.; Marzani, Alessandro; Daraio, Chiara

    2018-05-01

    We investigate the interaction of guided surface acoustic modes (GSAMs) in unconsolidated granular media with a metasurface, consisting of an array of vertical oscillators. We experimentally observe the hybridization of the lowest-order GSAM at the metasurface resonance, and note the absence of mode delocalization found in homogeneous media. Our numerical studies reveal how the stiffness gradient induced by gravity in granular media causes a down-conversion of all the higher-order GSAMs, which preserves the acoustic energy confinement. We anticipate these findings to have implications in the design of seismic-wave protection devices in stratified soils.

  14. Mathematical Simulation of Convective Processes in the Liquid Core of the Earth and Implications for the Interpretation of Geomagnetic Field Variations in Polar Latitudes

    NASA Astrophysics Data System (ADS)

    Abakumov, M. V.; Chechetkin, V. M.; Shalimov, S. L.

    2018-05-01

    The flow structure induced by thermal convection in a rotating spherical shell with viscous boundary conditions is considered under the assumption that the differential rotation of the core relative to the mantle is absent. The radial, azimuthal, and meridional components of the flow's velocity and helicity are studied. With the magnetic field assumed to be frozen into a liquid (frozen-flux hypothesis), it is shown that the numerical results fit the observations of the geomagnetic field variations close to the pole.

  15. Holography and off-center collisions of localized shock waves

    DOE PAGES

    Chesler, Paul M.; Yaffe, Laurence G.

    2015-10-12

    Using numerical holography, we study the collision, at non-zero impact parameter, of bounded, localized distributions of energy density chosen to mimic relativistic heavy ion collisions, in strongly coupled N=4 supersymmetric Yang-Mills theory. Both longitudinal and transverse dynamics in the dual field theory are properly described. Using the gravitational description, we solve 5D Einstein equations with no dimensionality reducing symmetry restrictions to find the asymptotically anti-de Sitter spacetime geometry. Here, the implications of our results on the understanding of early stages of heavy ion collisions, including the development of transverse radial flow, are discussed.

  16. Anomalous thermomechanical properties of a self-propelled colloidal fluid

    NASA Astrophysics Data System (ADS)

    Mallory, S. A.; Šarić, A.; Valeriani, C.; Cacciuto, A.

    2014-05-01

    We use numerical simulations to compute the equation of state of a suspension of spherical self-propelled nanoparticles in two and three dimensions. We study in detail the effect of excluded volume interactions and confinement as a function of the system's temperature, concentration, and strength of the propulsion. We find a striking nonmonotonic dependence of the pressure on the temperature and provide simple scaling arguments to predict and explain the occurrence of such anomalous behavior. We explicitly show how our results have important implications for the effective forces on passive components suspended in a bath of active particles.

  17. The role of β-adrenergic blockers in Parkinson's disease: possible genetic and cell-signaling mechanisms.

    PubMed

    Luong, Khanh vinh quoc; Nguyen, Lan Thi Hoàng

    2013-06-01

    Genetic studies have identified numerous factors linking β-adrenergic blockade to Parkinson's disease (PD), including human leukocyte antigen genes, the renin-angiotensin system, poly(adenosine diphosphate-ribose) polymerase 1, nerve growth factor, vascular endothelial growth factor, and the reduced form of nicotinamide adenine dinucleotide phosphate. β-Adrenergic blockade has also been implicated in PD via its effects on matrix metalloproteinases, mitogen-activated protein kinase pathways, prostaglandins, cyclooxygenase 2, and nitric oxide synthase. β-Adrenergic blockade may have a significant role in PD; therefore, the characterization of β-adrenergic blockade in patients with PD is needed.

  18. Heat and Mass Transfer in Unsteady Rotating Fluid Flow with Binary Chemical Reaction and Activation Energy

    PubMed Central

    Awad, Faiz G.; Motsa, Sandile; Khumalo, Melusi

    2014-01-01

    In this study, the Spectral Relaxation Method (SRM) is used to solve the coupled highly nonlinear system of partial differential equations due to an unsteady flow over a stretching surface in an incompressible rotating viscous fluid in presence of binary chemical reaction and Arrhenius activation energy. The velocity, temperature and concentration distributions as well as the skin-friction, heat and mass transfer coefficients have been obtained and discussed for various physical parametric values. The numerical results obtained by (SRM) are then presented graphically and discussed to highlight the physical implications of the simulations. PMID:25250830

  19. Movies and juvenile delinquency: an overview.

    PubMed

    Snyder, S

    1991-01-01

    Film viewing may affect the juvenile delinquent through the processes known as social learning and instigation. Identification with the movie and its characters by the delinquent viewer is common, and studies have consistently demonstrated that films can affect delinquents, although in some cases the effects are small. Numerous examples of how films may serve as either the initiator or the final common pathway of delinquent acts are presented. However, prosocial aspects of films dealing with delinquency may exert a positive influence on the juvenile delinquent. Treatment implications of these observations are discussed from social learning and other perspectives.

  20. The Burden of Stigma on Health and Well-Being: A Taxonomy of Concealment, Course, Disruptiveness, Aesthetics, Origin, and Peril Across 93 Stigmas.

    PubMed

    Pachankis, John E; Hatzenbuehler, Mark L; Wang, Katie; Burton, Charles L; Crawford, Forrest W; Phelan, Jo C; Link, Bruce G

    2018-04-01

    Most individuals are stigmatized at some point. However, research often examines stigmas separately, thus underestimating the overall impact of stigma and precluding comparisons across stigmatized identities and conditions. In their classic text, Social Stigma: The Psychology of Marked Relationships, Edward Jones and colleagues laid the groundwork for unifying the study of different stigmas by considering the shared dimensional features of stigmas: aesthetics, concealability, course, disruptiveness, origin, peril. Despite the prominence of this framework, no study has documented the extent to which stigmas differ along these dimensions, and the implications of this variation for health and well-being. We reinvigorated this framework to spur a comprehensive account of stigma's impact by classifying 93 stigmas along these dimensions. With the input of expert and general public raters, we then located these stigmas in a six-dimensional space and created discrete clusters organized around these dimensions. Next, we linked this taxonomy to health and stigma-related mechanisms. This quantitative taxonomy offers parsimonious insights into the relationship among the numerous qualities of numerous stigmas and health.

  1. A preliminary study of the application of HCMM satellite data to define initial and boundary conditions for numerical models: A case study in St. Louis, Missouri

    NASA Technical Reports Server (NTRS)

    Vukovich, F. M. (Principal Investigator)

    1982-01-01

    Infrared and visible HCMM data were used to examine the potential application of these data to define initial and boundary conditions for mesoscale numerical models. Various boundary layer models were used to calculate the distribution of the surface heat flux, specific humidity depression (the difference between the specific humidity in the air at approxmately the 10 m level and the specific humidity at the ground), and the eddy vicosity in a 72 km by 72 km area centered about St. Louis, Missouri. Various aspects of the implications of the results on the meteorology of St. Louis are discussed. Overall, the results indicated that a reasonable estimate of the surface heat flux, urban albedo, ground temperature, and specific humidity depression can be obtained using HCMM satellite data. Values of the ground-specific humidity can be obtained if the distribution of the air-specific humidity is available. More research is required in estimating the absolute magnitude of the specific humidity depression because calculations may be sensitive to model parameters.

  2. Assessing disease-modifying effects of norepinephrine in Down syndrome and Alzheimer's disease.

    PubMed

    Ponnusamy, Ravikumar; McNerney, M Windy; Moghadam, Shahrzad; Salehi, Ahmad

    2017-11-08

    Building upon the knowledge that a number of important brain circuits undergo significant degeneration in Alzheimer's disease, numerous recent studies suggest that the norepinephrine-ergic system in the brainstem undergoes significant alterations early in the course of both Alzheimer's disease and Down syndrome. Massive projections from locus coeruleus neurons to almost the entire brain, extensive innervation of brain capillaries, and widespread distribution of noradrenergic receptors enable the norepinephrine-ergic system to play a crucial role in neural processes, including cognitive function. These anatomical and functional characteristics support the role of the norepinephrine-ergic system as an important target for developing new therapies for cognitive dysfunction. Careful neuropathological examinations using postmortem samples from individuals with Alzheimer's disease have implicated the role of the norepinephrine-ergic system in the etiopathogenesis of Alzheimer's disease. Furthermore, numerous studies have supported the existence of a strong interaction between norepinephrine-ergic and neuroimmune systems. We explore the interaction between the two systems that could play a role in the disease-modifying effects of norepinephrine in Alzheimer's disease and Down syndrome. Copyright © 2017. Published by Elsevier B.V.

  3. Numerical modeling of solute transport in a sand tank physical model under varying hydraulic gradient and hydrological stresses

    NASA Astrophysics Data System (ADS)

    Atlabachew, Abunu; Shu, Longcang; Wu, Peipeng; Zhang, Yongjie; Xu, Yang

    2018-03-01

    This laboratory study improves the understanding of the impacts of horizontal hydraulic gradient, artificial recharge, and groundwater pumping on solute transport through aquifers. Nine experiments and numerical simulations were carried out using a sand tank. The variable-density groundwater flow and sodium chloride transport were simulated using the three-dimensional numerical model SEAWAT. Numerical modelling results successfully reproduced heads and concentrations observed in the sand tank. A higher horizontal hydraulic gradient enhanced the migration of sodium chloride, particularly in the groundwater flow direction. The application of constant artificial recharge increased the spread of the sodium chloride plume in both the longitudinal and lateral directions. In addition, groundwater pumping accelerated spreading of the sodium chloride plume towards the pumping well. Both higher hydraulic gradient and pumping rate generated oval-shaped plumes in the horizontal plane. However, the artificial recharge process produced stretched plumes. These effects of artificial recharge and groundwater pumping were greater under higher hydraulic gradient. The concentration breakthrough curves indicated that emerging solutions never attained the concentration of the originally injected solution. This is probably because of sorption of sodium chloride onto the silica sand and/or the exchange of sodium chloride between the mobile and immobile liquid domains. The fingering and protruding plume shapes in the numerical models constitute instability zones produced by buoyancy-driven flow. Overall, the results have substantiated the influences of hydraulic gradient, boundary condition, artificial recharge, pumping rate and density differences on solute transport through a homogeneous unconfined aquifer. The implications of these findings are important for managing liquid wastes.

  4. New variational bounds on convective transport. II. Computations and implications

    NASA Astrophysics Data System (ADS)

    Souza, Andre; Tobasco, Ian; Doering, Charles R.

    2016-11-01

    We study the maximal rate of scalar transport between parallel walls separated by distance h, by an incompressible fluid with scalar diffusion coefficient κ. Given velocity vector field u with intensity measured by the Péclet number Pe =h2 < | ∇ u |2 >1/2 / κ (where < . > is space-time average) the challenge is to determine the largest enhancement of wall-to-wall scalar flux over purely diffusive transport, i.e., the Nusselt number Nu . Variational formulations of the problem are studied numerically and optimizing flow fields are computed over a range of Pe . Implications of this optimal wall-to-wall transport problem for the classical problem of Rayleigh-Bénard convection are discussed: the maximal scaling Nu Pe 2 / 3 corresponds, via the identity Pe2 = Ra (Nu - 1) where Ra is the usual Rayleigh number, to Nu Ra 1 / 2 as Ra -> ∞ . Supported in part by National Science Foundation Graduate Research Fellowship DGE-0813964, awards OISE-0967140, PHY-1205219, DMS-1311833, and DMS-1515161, and the John Simon Guggenheim Memorial Foundation.

  5. Buried treasure: evolutionary perspectives on microbial iron piracy

    PubMed Central

    Barber, Matthew F.; Elde, Nels C.

    2015-01-01

    Host-pathogen interactions provide valuable systems for the study of evolutionary genetics and natural selection. The sequestration of essential iron has emerged as a critical innate defense system termed nutritional immunity, leading pathogens to evolve mechanisms of `iron piracy' to scavenge this metal from host proteins. This battle for iron carries numerous consequences not only for host-pathogen evolution, but also microbial community interactions. Here we highlight recent and potential future areas of investigation on the evolutionary implications of microbial iron piracy in relation to molecular arms races, host range, competition, and virulence. Applying evolutionary genetic approaches to the study of microbial iron acquisition could also provide new inroads for understanding and combating infectious disease. PMID:26431675

  6. The role of vitamin D in malaria.

    PubMed

    Lương, Khanh Vinh Quốc; Nguyễn, Lan Thi Hoàng

    2015-01-15

    An abnormal calcium-parathyroid hormone (PTH)-vitamin D axis has been reported in patients with malaria infection. A role for vitamin D in malaria has been suggested by many studies. Genetic studies have identified numerous factors that link vitamin D to malaria, including human leukocyte antigen genes, toll-like receptors, heme oxygenase-1, angiopoietin-2, cytotoxic T lymphocyte antigen-4, nucleotide-binding oligomerization domain-like receptors, and Bcl-2. Vitamin D has also been implicated in malaria via its effects on the Bacillus Calmette-Guerin (BCG) vaccine, matrix metalloproteinases, mitogen-activated protein kinase pathways, prostaglandins, reactive oxidative species, and nitric oxide synthase. Vitamin D may be important in malaria; therefore, additional research on its role in malaria is needed.

  7. Dynamical models of happiness with fractional order

    NASA Astrophysics Data System (ADS)

    Song, Lei; Xu, Shiyun; Yang, Jianying

    2010-03-01

    This present study focuses on a dynamical model of happiness described through fractional-order differential equations. By categorizing people of different personality and different impact factor of memory (IFM) with different set of model parameters, it is demonstrated via numerical simulations that such fractional-order models could exhibit various behaviors with and without external circumstance. Moreover, control and synchronization problems of this model are discussed, which correspond to the control of emotion as well as emotion synchronization in real life. This study is an endeavor to combine the psychological knowledge with control problems and system theories, and some implications for psychotherapy as well as hints of a personal approach to life are both proposed.

  8. Three- and two-dimensional simulations of counter-propagating shear experiments at high energy densities at the National Ignition Facility

    DOE PAGES

    Wang, Ping; Zhou, Ye; MacLaren, Stephan A.; ...

    2015-11-06

    Three- and two-dimensional numerical studies have been carried out to simulate recent counter-propagating shear flow experiments on the National Ignition Facility. A multi-physics three-dimensional, time-dependent radiation hydrodynamics simulation code is used. Using a Reynolds Averaging Navier-Stokes model, we show that the evolution of the mixing layer width obtained from the simulations agrees well with that measured from the experiments. A sensitivity study is conducted to illustrate a 3D geometrical effect that could confuse the measurement at late times, if the energy drives from the two ends of the shock tube are asymmetric. Implications for future experiments are discussed.

  9. Life Satisfaction Among Mothers of Individuals with Prader-Willi Syndrome.

    PubMed

    Shivers, Carolyn M; Leonczyk, Caroline L; Dykens, Elisabeth M

    2016-06-01

    Mothers of individuals with Prader-Willi syndrome (PWS) often experience numerous stressors, even when compared to mothers of children with other intellectual and developmental disabilities. Despite this, these mothers show great variability in self-reported life satisfaction. Using data from a longitudinal study of individuals with PWS and their families, the present study analyzed factors related to maternal life satisfaction, both cross-sectionally and over time. Results show that both child factors (e.g., behavior problems, hyperphagia) and maternal factors (e.g., stress, coping style) were significantly related to maternal life satisfaction. However, none of the tested variables predicted change in life satisfaction over time. Research and practice implications are discussed.

  10. How to model AGN feedback in cosmological simulations?

    NASA Astrophysics Data System (ADS)

    Sijacki, Debora

    2015-08-01

    Hydrodynamical cosmological simulations are one of the most powerful tools to study the formation and evolution of galaxies in the fully non-linear regime. Despite several recent successes in simulating Milky Way look-alikes, self-consistent, ab-initio models are still a long way off. In this talk I will review numerical and physical uncertainties plaguing current state-of-the-art cosmological simulations of galaxy formation. I will then discuss which feedback mechanisms are needed to reproduce realistic stellar masses and galaxy morphologies in the present day Universe and argue that the black hole feedback is necessary for the quenching of massive galaxies. I will then demonstrate how black hole - host galaxy scaling relations depend on galaxy morphology and colour, highlighting the implications for the co-evolutionary picture between galaxies and their central black holes. In the second part of the talk I will present a novel method that permits to resolve gas flows around black holes all the way from large cosmological scales to the Bondi radii of black holes themselves. I will demonstrate that with this new numerical technique it is possible to estimate much more accurately gas properties in the vicinity of black holes than has been feasible before in galaxy and cosmological simulations, allowing to track reliably gas angular momentum transport from Mpc to pc scales. Finally, I will also discuss if AGN-driven outflows are more likely to be energy- or momentum-driven and what implications this has for the redshift evolution of black hole - host galaxy scaling relations.

  11. Prostate cancer epigenetics and its clinical implications

    PubMed Central

    Yegnasubramanian, Srinivasan

    2016-01-01

    Normal cells have a level of epigenetic programming that is superimposed on the genetic code to establish and maintain their cell identity and phenotypes. This epigenetic programming can be thought as the architecture, a sort of cityscape, that is built upon the underlying genetic landscape. The epigenetic programming is encoded by a complex set of chemical marks on DNA, on histone proteins in nucleosomes, and by numerous context-specific DNA, RNA, protein interactions that all regulate the structure, organization, and function of the genome in a given cell. It is becoming increasingly evident that abnormalities in both the genetic landscape and epigenetic cityscape can cooperate to drive carcinogenesis and disease progression. Large-scale cancer genome sequencing studies have revealed that mutations in genes encoding the enzymatic machinery for shaping the epigenetic cityscape are among the most common mutations observed in human cancers, including prostate cancer. Interestingly, although the constellation of genetic mutations in a given cancer can be quite heterogeneous from person to person, there are numerous epigenetic alterations that appear to be highly recurrent, and nearly universal in a given cancer type, including in prostate cancer. The highly recurrent nature of these alterations can be exploited for development of biomarkers for cancer detection and risk stratification and as targets for therapeutic intervention. Here, we explore the basic principles of epigenetic processes in normal cells and prostate cancer cells and discuss the potential clinical implications with regards to prostate cancer biomarker development and therapy. PMID:27212125

  12. Prostate cancer epigenetics and its clinical implications.

    PubMed

    Yegnasubramanian, Srinivasan

    2016-01-01

    Normal cells have a level of epigenetic programming that is superimposed on the genetic code to establish and maintain their cell identity and phenotypes. This epigenetic programming can be thought as the architecture, a sort of cityscape, that is built upon the underlying genetic landscape. The epigenetic programming is encoded by a complex set of chemical marks on DNA, on histone proteins in nucleosomes, and by numerous context-specific DNA, RNA, protein interactions that all regulate the structure, organization, and function of the genome in a given cell. It is becoming increasingly evident that abnormalities in both the genetic landscape and epigenetic cityscape can cooperate to drive carcinogenesis and disease progression. Large-scale cancer genome sequencing studies have revealed that mutations in genes encoding the enzymatic machinery for shaping the epigenetic cityscape are among the most common mutations observed in human cancers, including prostate cancer. Interestingly, although the constellation of genetic mutations in a given cancer can be quite heterogeneous from person to person, there are numerous epigenetic alterations that appear to be highly recurrent, and nearly universal in a given cancer type, including in prostate cancer. The highly recurrent nature of these alterations can be exploited for development of biomarkers for cancer detection and risk stratification and as targets for therapeutic intervention. Here, we explore the basic principles of epigenetic processes in normal cells and prostate cancer cells and discuss the potential clinical implications with regards to prostate cancer biomarker development and therapy.

  13. Sex Differences in the Implications of Partner Physical Attractiveness for the Trajectory of Marital Satisfaction

    PubMed Central

    Meltzer, Andrea L.; McNulty, James K.; Jackson, Grace; Karney, Benjamin R.

    2014-01-01

    Do men value physical attractiveness in a mate more than women? Scientists in numerous disciplines believe that they do, but recent research using speed-dating paradigms suggests that males and females are equally influenced by physical attractiveness when choosing potential mates. Nevertheless, the premise of the current work is that sex differences in the importance of physical attractiveness are most likely to emerge in research on long-term relationships. Accordingly, the current work drew from four independent, longitudinal studies to examine sex differences in the implications of partner physical attractiveness for trajectories of marital satisfaction. In all four studies, both partners’ physical attractiveness was objectively rated at baseline and both partners reported their marital satisfaction up to eight times over the first four years of marriage. Whereas husbands were more satisfied at the beginning of the marriage and remained more satisfied over the next four years to the extent that they had an attractive wife, wives were no more or less satisfied initially or over the next four years to the extent that they had an attractive husband. Most importantly, a direct test indicated that partner physical attractiveness played a larger role in predicting husbands’ satisfaction than predicting wives’ satisfaction. These findings strengthen support for the idea that gender differences in self-reported preferences for physical attractiveness do have implications for long-term relationship outcomes. PMID:24128188

  14. Teaching Students Financial Literacy Using the Internet

    ERIC Educational Resources Information Center

    Risinger, C. Frederick

    2009-01-01

    As the author researched the causes and implications of the current economic crisis, he came across numerous commentaries on how financial literacy was seldom taught (or taught well) in U.S. schools. This article, aimed at teachers and supervisors at all grade levels, describes some Internet sites that: (1) explain the collapse of the housing…

  15. Taking Stock: Implications of a New Vision of Science Learning for State Science Assessment

    ERIC Educational Resources Information Center

    Wertheim, Jill

    2016-01-01

    This article presents the author's response to the article "Taking Stock: Existing Resources for Assessing a New Vision of Science Learning" by Alonzo and Ke (this issue), which identifies numerous challenges that the Next Generation Science Standards (NGSS) pose for large-scale assessment. Jill Werthem comments that among those…

  16. Physiological implications of anthropogenic environmental calcium depletion

    Treesearch

    Catherine H. Borer; Paul G. Schaberg; Donald H. DeHayes; Gary J. Hawley

    2001-01-01

    Recent evidence indicates that numerous anthropogenic factors can deplete calcium (Ca) from forested ecosystems. Although it is difficult to quantify the extent of this depletion, some reports indicate that the magnitude of Ca losses may be substantial. The potential for Ca depletion raises important questions about tree health. Only a fraction of foliar Ca is...

  17. Identifying Simple Numerical Stimuli: Processing Inefficiencies Exhibited by Arithmetic Learning Disabled Children.

    ERIC Educational Resources Information Center

    Koontz, Kristine L.; Berch, Daniel B.

    1996-01-01

    Children with arithmetic learning disabilities (n=16) and normally achieving controls (n=16) in grades 3-5 were administered a battery of computerized tasks. Memory spans for both letters and digits were found to be smaller among the arithmetic learning disabled children. Implications for teaching are discussed. (Author/CMS)

  18. Obligations to High Priority Target Groups: Philosophical Implications.

    ERIC Educational Resources Information Center

    Christmas, June Jackson

    Community mental health center services must be most plentiful where the need is greatest and must be appropriate and available to meet these needs. The first high priority group, according to statistics on juvenile delinquency, and narcotics, is the black inner city. Socio-psychiatric services, numerous enough in quantity to begin to meet needs…

  19. A Reconceptualization of Physical Education: The Intersection of Gender/Race/Social Class

    ERIC Educational Resources Information Center

    Azzarito, Laura; Solomon, Melinda A.

    2005-01-01

    Over the past several years, numerous reports have reported data documenting declining participation in physical activity among youth. We argue that the gender, race and social class differences in these data have not been an important consideration, and that understanding the implications of these differences is crucial for improving physical…

  20. Promoting College Access among Latina/o English Language Learners: Implications for Professional School Counselors

    ERIC Educational Resources Information Center

    Cook, Amy L.; Pérusse, Rachelle; Rojas, Eliana D.

    2015-01-01

    According to the U.S. Department of Education (2010), Latina/o English language learners (ELL students) are less likely to complete high school and attend college compared to their White non-Latina/o peers. Numerous factors affect Latina/o ELL students' academic achievement, including insufficient resources, acculturation issues, attitudinal…

  1. A shallow water model for the propagation of tsunami via Lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Zergani, Sara; Aziz, Z. A.; Viswanathan, K. K.

    2015-01-01

    An efficient implementation of the lattice Boltzmann method (LBM) for the numerical simulation of the propagation of long ocean waves (e.g. tsunami), based on the nonlinear shallow water (NSW) wave equation is presented. The LBM is an alternative numerical procedure for the description of incompressible hydrodynamics and has the potential to serve as an efficient solver for incompressible flows in complex geometries. This work proposes the NSW equations for the irrotational surface waves in the case of complex bottom elevation. In recent time, equation involving shallow water is the current norm in modelling tsunami operations which include the propagation zone estimation. Several test-cases are presented to verify our model. Some implications to tsunami wave modelling are also discussed. Numerical results are found to be in excellent agreement with theory.

  2. Complexity in Soil Systems: What Does It Mean and How Should We Proceed?

    NASA Astrophysics Data System (ADS)

    Faybishenko, B.; Molz, F. J.; Brodie, E.; Hubbard, S. S.

    2015-12-01

    The complex soil systems approach is needed fundamentally for the development of integrated, interdisciplinary methods to measure and quantify the physical, chemical and biological processes taking place in soil, and to determine the role of fine-scale heterogeneities. This presentation is aimed at a review of the concepts and observations concerning complexity and complex systems theory, including terminology, emergent complexity and simplicity, self-organization and a general approach to the study of complex systems using the Weaver (1948) concept of "organized complexity." These concepts are used to provide understanding of complex soil systems, and to develop experimental and mathematical approaches to soil microbiological processes. The results of numerical simulations, observations and experiments are presented that indicate the presence of deterministic chaotic dynamics in soil microbial systems. So what are the implications for the scientists who wish to develop mathematical models in the area of organized complexity or to perform experiments to help clarify an aspect of an organized complex system? The modelers have to deal with coupled systems having at least three dependent variables, and they have to forgo making linear approximations to nonlinear phenomena. The analogous rule for experimentalists is that they need to perform experiments that involve measurement of at least three interacting entities (variables depending on time, space, and each other). These entities could be microbes in soil penetrated by roots. If a process being studied in a soil affects the soil properties, like biofilm formation, then this effect has to be measured and included. The mathematical implications of this viewpoint are examined, and results of numerical solutions to a system of equations demonstrating deterministic chaotic behavior are also discussed using time series and the 3D strange attractors.

  3. Model-order reduction of lumped parameter systems via fractional calculus

    NASA Astrophysics Data System (ADS)

    Hollkamp, John P.; Sen, Mihir; Semperlotti, Fabio

    2018-04-01

    This study investigates the use of fractional order differential models to simulate the dynamic response of non-homogeneous discrete systems and to achieve efficient and accurate model order reduction. The traditional integer order approach to the simulation of non-homogeneous systems dictates the use of numerical solutions and often imposes stringent compromises between accuracy and computational performance. Fractional calculus provides an alternative approach where complex dynamical systems can be modeled with compact fractional equations that not only can still guarantee analytical solutions, but can also enable high levels of order reduction without compromising on accuracy. Different approaches are explored in order to transform the integer order model into a reduced order fractional model able to match the dynamic response of the initial system. Analytical and numerical results show that, under certain conditions, an exact match is possible and the resulting fractional differential models have both a complex and frequency-dependent order of the differential operator. The implications of this type of approach for both model order reduction and model synthesis are discussed.

  4. Freed by interaction kinetic states in the Harper model

    NASA Astrophysics Data System (ADS)

    Frahm, Klaus M.; Shepelyansky, Dima L.

    2015-12-01

    We study the problem of two interacting particles in a one-dimensional quasiperiodic lattice of the Harper model. We show that a short or long range interaction between particles leads to emergence of delocalized pairs in the non-interacting localized phase. The properties of these freed by interaction kinetic states (FIKS) are analyzed numerically including the advanced Arnoldi method. We find that the number of sites populated by FIKS pairs grows algebraically with the system size with the maximal exponent b = 1, up to a largest lattice size N = 10 946 reached in our numerical simulations, thus corresponding to a complete delocalization of pairs. For delocalized FIKS pairs the spectral properties of such quasiperiodic operators represent a deep mathematical problem. We argue that FIKS pairs can be detected in the framework of recent cold atom experiments [M. Schreiber et al., Science 349, 842 (2015)] by a simple setup modification. We also discuss possible implications of FIKS pairs for electron transport in the regime of charge-density wave and high T c superconductivity.

  5. Excitation of Plasma Waves in Aurora by Electron Beams

    NASA Technical Reports Server (NTRS)

    daSilva, C. E.; Vinas, A. F.; deAssis, A. S.; deAzevedo, C. A.

    1996-01-01

    In this paper, we study numerically the excitation of plasma waves by electron beams, in the auroral region above 2000 km of altitude. We have solved the fully kinetic dispersion relation, using numerical method and found the real frequency and the growth rate of the plasma wave modes. We have examined the instability properties of low-frequency waves such as the Electromagnetic Ion Cyclotron (EMIC) wave as well as Lower-Hybrid (LH) wave in the range of high-frequency. In all cases, the source of free energy are electron beams propagating parallel to the geomagnetic field. We present some features of the growth rate modes, when the cold plasma parameters are changed, such as background electrons and ions species (H(+) and O(+)) temperature, density or the electron beam density and/or drift velocity. These results can be used in a test-particle simulation code, to investigate the ion acceleration and their implication in the auroral acceleration processes, by wave-particle interaction.

  6. Operational implications of some NACA/NASA rotary wing induced velocity studies

    NASA Technical Reports Server (NTRS)

    Heyson, H. H.

    1980-01-01

    Wind tunnel measurements show that the wake of a rotor, except at near-hovering speeds, is not like that of a propeller. The wake is more like that of a wing except that, because of the slow speeds, the wake velocities may be much greater. The helicopter can produce a wake hazard to following light aircraft that is disproportionately great compared to an equivalent fixed-wing aircraft. This hazard should be recognized by both pilots and airport controllers when operating in congested areas. Even simple momentum theory shows that, in autorotation and partial-power descent, the required power is a complex function of both airspeed and descent angle. The nonlinear characteristic, together with an almost total lack of usable instrumentation at low airspeeds, has led to numerous power-settling accidents. The same theory shows that there is a minimum forward speed at which a rotor can autorotate. Neglect of, or inadequate appraisal of this minimum speed has also led to numerous accidents. Ground effect and the problems it creates is discussed.

  7. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Naughton, M.J.; Bourke, W.; Browning, G.L.

    The convergence of spectral model numerical solutions of the global shallow-water equations is examined as a function of the time step and the spectral truncation. The contributions to the errors due to the spatial and temporal discretizations are separately identified and compared. Numerical convergence experiments are performed with the inviscid equations from smooth (Rossby-Haurwitz wave) and observed (R45 atmospheric analysis) initial conditions, and also with the diffusive shallow-water equations. Results are compared with the forced inviscid shallow-water equations case studied by Browning et al. Reduction of the time discretization error by the removal of fast waves from the solution usingmore » initialization is shown. The effects of forcing and diffusion on the convergence are discussed. Time truncation errors are found to dominate when a feature is large scale and well resolved; spatial truncation errors dominate for small-scale features and also for large scale after the small scales have affected them. Possible implications of these results for global atmospheric modeling are discussed. 31 refs., 14 figs., 4 tabs.« less

  8. Large-scale gas dynamical processes affecting the origin and evolution of gaseous galactic halos

    NASA Technical Reports Server (NTRS)

    Shapiro, Paul R.

    1991-01-01

    Observations of galactic halo gas are consistent with an interpretation in terms of the galactic fountain model in which supernova heated gas in the galactic disk escapes into the halo, radiatively cools and forms clouds which fall back to the disk. The results of a new study of several large-scale gas dynamical effects which are expected to occur in such a model for the origin and evolution of galactic halo gas will be summarized, including the following: (1) nonequilibrium absorption line and emission spectrum diagnostics for radiatively cooling halo gas in our own galaxy, as well the implications of such absorption line diagnostics for the origin of quasar absorption lines in galactic halo clouds of high redshift galaxies; (2) numerical MHD simulations and analytical analysis of large-scale explosions ad superbubbles in the galactic disk and halo; (3) numerical MHD simulations of halo cloud formation by thermal instability, with and without magnetic field; and (4) the effect of the galactic fountain on the galactic dynamo.

  9. Modeling Extra-Long Tsunami Propagation: Assessing Data, Model Accuracy and Forecast Implications

    NASA Astrophysics Data System (ADS)

    Titov, V. V.; Moore, C. W.; Rabinovich, A.

    2017-12-01

    Detecting and modeling tsunamis propagating tens of thousands of kilometers from the source is a formidable scientific challenge and seemingly satisfies only scientific curiosity. However, results of such analyses produce a valuable insight into the tsunami propagation dynamics, model accuracy and would provide important implications for tsunami forecast. The Mw = 9.3 megathrust earthquake of December 26, 2004 off the coast of Sumatra generated a tsunami that devastated Indian Ocean coastlines and spread into the Pacific and Atlantic oceans. The tsunami was recorded by a great number of coastal tide gauges, including those located in 15-25 thousand kilometers from the source area. To date, it is still the farthest instrumentally detected tsunami. The data from these instruments throughout the world oceans enabled to estimate various statistical parameters and energy decay of this event. High-resolution records of this tsunami from DARTs 32401 (offshore of northern Chile), 46405 and NeMO (both offshore of the US West Coast), combined with the mainland tide gauge measurements enabled us to examine far-field characteristics of the 2004 in the Pacific Ocean and to compare the results of global numerical simulations with the observations. Despite their small heights (less than 2 cm at deep-ocean locations), the records demonstrated consistent spatial and temporal structure. The numerical model described well the frequency content, amplitudes and general structure of the observed waves at deep-ocean and coastal gages. We present analysis of the measurements and comparison with model data to discuss implication for tsunami forecast accuracy. Model study for such extreme distances from the tsunami source and at extra-long times after the event is an attempt to find accuracy bounds for tsunami models and accuracy limitations of model use for forecast. We discuss results in application to tsunami model forecast and tsunami modeling in general.

  10. Medicinal Plants of the Family Lamiaceae in Pain Therapy: A Review

    PubMed Central

    Uritu, Cristina M.; Mihai, Cosmin T.; Stanciu, Gabriela-Dumitrita; Leon-Constantin, Maria-Magdalena; Stefanescu, Raluca; Bild, Veronica

    2018-01-01

    Recently, numerous side effects of synthetic drugs have lead to using medicinal plants as a reliable source of new therapy. Pain is a global public health problem with a high impact on life quality and a huge economic implication, becoming one of the most important enemies in modern medicine. The medicinal use of plants as analgesic or antinociceptive drugs in traditional therapy is estimated to be about 80% of the world population. The Lamiaceae family, one of the most important herbal families, incorporates a wide variety of plants with biological and medical applications. In this study, the analgesic activity, possible active compounds of Lamiaceae genus, and also the possible mechanism of actions of these plants are presented. The data highlighted in this review paper provide valuable scientific information for the specific implications of Lamiaceae plants in pain modulation that might be used for isolation of potentially active compounds from some of these medicinal plants in future and formulation of commercial therapeutic agents. PMID:29854039

  11. Shock-transformation of whitlockite to merrillite and the implications for meteoritic phosphate

    DOE PAGES

    Adcock, C. T.; Tschauner, O.; Hausrath, E. M.; ...

    2017-03-06

    Meteorites represent the only samples available for study on Earth of a number of planetary bodies. The minerals within meteorites therefore hold the key to addressing numerous questions about our solar system. Of particular interest is the Ca-phosphate mineral merrillite, the anhydrous end-member of the merrillite-whitlockite solid solution series. For example, the anhydrous nature of merrillite in Martian meteorites has been interpreted as evidence of water-limited late-stage Martian melts. However, recent research on apatite in the same meteorites suggests higher water content in melts. One complication of using meteorites rather than direct samples is the shock compression all meteorites havemore » experienced, which can alter meteorite mineralogy. Here we show whitlockite transformation into merrillite by shock-compression levels relevant to meteorites, including Martian meteorites. The results open the possibility that at least part of meteoritic merrillite may have originally been H + -bearing whitlockite with implications for interpreting meteorites and the need for future sample return.« less

  12. Shock-transformation of whitlockite to merrillite and the implications for meteoritic phosphate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adcock, C. T.; Tschauner, O.; Hausrath, E. M.

    Meteorites represent the only samples available for study on Earth of a number of planetary bodies. The minerals within meteorites therefore hold the key to addressing numerous questions about our solar system. Of particular interest is the Ca-phosphate mineral merrillite, the anhydrous end-member of the merrillite-whitlockite solid solution series. For example, the anhydrous nature of merrillite in Martian meteorites has been interpreted as evidence of water-limited late-stage Martian melts. However, recent research on apatite in the same meteorites suggests higher water content in melts. One complication of using meteorites rather than direct samples is the shock compression all meteorites havemore » experienced, which can alter meteorite mineralogy. Here we show whitlockite transformation into merrillite by shock-compression levels relevant to meteorites, including Martian meteorites. The results open the possibility that at least part of meteoritic merrillite may have originally been H + -bearing whitlockite with implications for interpreting meteorites and the need for future sample return.« less

  13. Exsolution lamellae as fast diffusion pathways in rutile: implications for U-Pb thermochronology and Zr thermometry

    NASA Astrophysics Data System (ADS)

    Smye, A.; Seman, S.; Roberts, N. M. W.; Condon, D. J.; Davis, B.

    2017-12-01

    Geophysical processes impart characteristic thermal signatures to the lithosphere. Near-continuous thermal histories can be obtained from inversion of intracrystalline U-Pb age profiles in rutile and apatite provided that it can be shown that profile formed in response to Fickian-type diffusion. Here, we present the results of a combined LA-ICPMS and ID-TIMS U-Pb study on rutile grains from two garnet-bearing granulite xenoliths from a kimberlite in the Archean Slave province. Interpreted using numerical models, we show that the rutile U-Pb isotope systematics are consistent with slow-cooling following crystallization at 1.2 Ga, contemporaneous with the Mackenzie dike swarm. However, inversion of rutile U-Pb age gradients is complicated by the ubiquitous presence of ilmenite exsolution lamellae. We show that these lamellae act as fast diffusion pathways for Pb and High Field Strength Elements, including Zr. This has important implications for the use of rutile as a U-Pb themochronometer and as a single-phase thermometer.

  14. Applying geologic sensitivity analysis to environmental risk management: The financial implications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rogers, D.T.

    The financial risks associated with environmental contamination can be staggering and are often difficult to identify and accurately assess. Geologic sensitivity analysis is gaining recognition as a significant and useful tool that can empower the user with crucial information concerning environmental risk management and brownfield redevelopment. It is particularly useful when (1) evaluating the potential risks associated with redevelopment of historical industrial facilities (brownfields) and (2) planning for future development, especially in areas of rapid development because the number of potential contaminating sources often increases with an increase in economic development. An examination of the financial implications relating to geologicmore » sensitivity analysis in southeastern Michigan from numerous case studies indicate that the environmental cost of contamination may be 100 to 1,000 times greater at a geologically sensitive location compared to the least sensitive location. Geologic sensitivity analysis has demonstrated that near-surface geology may influence the environmental impact of a contaminated site to a greater extent than the amount and type of industrial development.« less

  15. Shock-transformation of whitlockite to merrillite and the implications for meteoritic phosphate

    PubMed Central

    Adcock, C. T.; Tschauner, O.; Hausrath, E. M.; Udry, A.; Luo, S. N.; Cai, Y.; Ren, M.; Lanzirotti, A.; Newville, M.; Kunz, M.; Lin, C.

    2017-01-01

    Meteorites represent the only samples available for study on Earth of a number of planetary bodies. The minerals within meteorites therefore hold the key to addressing numerous questions about our solar system. Of particular interest is the Ca-phosphate mineral merrillite, the anhydrous end-member of the merrillite–whitlockite solid solution series. For example, the anhydrous nature of merrillite in Martian meteorites has been interpreted as evidence of water-limited late-stage Martian melts. However, recent research on apatite in the same meteorites suggests higher water content in melts. One complication of using meteorites rather than direct samples is the shock compression all meteorites have experienced, which can alter meteorite mineralogy. Here we show whitlockite transformation into merrillite by shock-compression levels relevant to meteorites, including Martian meteorites. The results open the possibility that at least part of meteoritic merrillite may have originally been H+-bearing whitlockite with implications for interpreting meteorites and the need for future sample return. PMID:28262701

  16. Nonlinear vibrations and dynamic stability of viscoelastic orthotropic rectangular plates

    NASA Astrophysics Data System (ADS)

    Eshmatov, B. Kh.

    2007-03-01

    This paper describes the analyses of the nonlinear vibrations and dynamic stability of viscoelastic orthotropic plates. The models are based on the Kirchhoff-Love (K.L.) hypothesis and Reissner-Mindlin (R.M.) generalized theory (with the incorporation of shear deformation and rotatory inertia) in geometrically nonlinear statements. It provides justification for the choice of the weakly singular Koltunov-Rzhanitsyn type kernel, with three rheological parameters. In addition, the implication of each relaxation kernel parameter has been studied. To solve problems of viscoelastic systems with weakly singular kernels of relaxation, a numerical method has been used, based on quadrature formulae. With a combination of the Bubnov-Galerkin and the presented method, problems of nonlinear vibrations and dynamic stability in viscoelastic orthotropic rectangular plates have been solved, according to the K.L. and R.M. hypotheses. A comparison of the results obtained via these theories is also presented. In all problems, the convergence of the Bubnov-Galerkin method has been investigated. The implications of material viscoelasticity on vibration and dynamic stability are presented graphically.

  17. Generalized Hill-stability criteria for hierarchical three-body systems at arbitrary inclinations

    NASA Astrophysics Data System (ADS)

    Grishin, Evgeni; Perets, Hagai B.; Zenati, Yossef; Michaely, Erez

    2017-04-01

    A fundamental aspect of the three-body problem is its stability. Most stability studies have focused on the co-planar three-body problem, deriving analytic criteria for the dynamical stability of such pro/retrograde systems. Numerical studies of inclined systems phenomenologically mapped their stability regions, but neither complement it by theoretical framework, nor provided satisfactory fit for their dependence on mutual inclinations. Here we present a novel approach to study the stability of hierarchical three-body systems at arbitrary inclinations, which accounts not only for the instantaneous stability of such systems, but also for the secular stability and evolution through Lidov-Kozai cycles and evection. We generalize the Hill-stability criteria to arbitrarily inclined triple systems, explain the existence of quasi-stable regimes and characterize the inclination dependence of their stability. We complement the analytic treatment with an extensive numerical study, to test our analytic results. We find excellent correspondence up to high inclinations (˜120°), beyond which the agreement is marginal. At such high inclinations, the stability radius is larger, the ratio between the outer and inner periods becomes comparable and our secular averaging approach is no longer strictly valid. We therefore combine our analytic results with polynomial fits to the numerical results to obtain a generalized stability formula for triple systems at arbitrary inclinations. Besides providing a generalized secular-based physical explanation for the stability of non-co-planar systems, our results have direct implications for any triple systems and, in particular, binary planets and moon/satellite systems; we briefly discuss the latter as a test case for our models.

  18. Implications of long tails in the distribution of mutant effects

    NASA Astrophysics Data System (ADS)

    Waxman, D.; Feng, J.

    2005-07-01

    Long-tailed distributions possess an infinite variance, yet a finite sample that is drawn from such a distribution has a finite variance. In this work we consider a model of a population subject to mutation, selection and drift. We investigate the implications of a long-tailed distribution of mutant allelic effects on the distribution of genotypic effects in a model with a continuum of allelic effects. While the analysis is confined to asexual populations, it does also have implications for sexual populations. We obtain analytical results for a selectively neutral population as well as one subject to selection. We supplement these analytical results with numerical simulations, to take into account genetic drift. We find that a long-tailed distribution of mutant effects may affect both the equilibrium and the evolutionary adaptive behaviour of a population.

  19. Carbon dioxide and climate: a second assessment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    For over a century, concern has been expressed that increases in atmospheric carbon dioxide (CO/sub 2/) concentration could affect global climate by changing the heat balance of the atmosphere and Earth. Observations reveal steadily increasing concentrations of CO/sub 2/, and experiments with numerical climate models indicate that continued increase would eventually produce significant climatic change. Comprehensive assessment of the issue will require projection of future CO/sub 2/ emissions and study of the disposition of this excess carbon in the atmosphere, ocean, and biota; the effect on climate; and the implications for human welfare. This study focuses on one aspect, estimationmore » of the effect on climate of assumed future increases in atmospheric CO/sub 2/. Conclusions are drawn principally from present-day numerical models of the climate system. To address the significant role of the oceans, the study also makes use of observations of the distributions of anthropogenic tracers other than CO/sub 2/. The rapid scientific developments in these areas suggest that periodic reassessments will be warranted. The starting point for the study was a similar 1979 review by a Climate Research Board panel chaired by the late Jule G. Charney. The present study has not found any new results that necessitate substantial revision of the conclusions of the Charney report.« less

  20. Does exposure to simulated patient cases improve accuracy of clinicians' predictive value estimates of diagnostic test results? A within-subjects experiment at St Michael's Hospital, Toronto, Canada.

    PubMed

    Armstrong, Bonnie; Spaniol, Julia; Persaud, Nav

    2018-02-13

    Clinicians often overestimate the probability of a disease given a positive test result (positive predictive value; PPV) and the probability of no disease given a negative test result (negative predictive value; NPV). The purpose of this study was to investigate whether experiencing simulated patient cases (ie, an 'experience format') would promote more accurate PPV and NPV estimates compared with a numerical format. Participants were presented with information about three diagnostic tests for the same fictitious disease and were asked to estimate the PPV and NPV of each test. Tests varied with respect to sensitivity and specificity. Information about each test was presented once in the numerical format and once in the experience format. The study used a 2 (format: numerical vs experience) × 3 (diagnostic test: gold standard vs low sensitivity vs low specificity) within-subjects design. The study was completed online, via Qualtrics (Provo, Utah, USA). 50 physicians (12 clinicians and 38 residents) from the Department of Family and Community Medicine at St Michael's Hospital in Toronto, Canada, completed the study. All participants had completed at least 1 year of residency. Estimation accuracy was quantified by the mean absolute error (MAE; absolute difference between estimate and true predictive value). PPV estimation errors were larger in the numerical format (MAE=32.6%, 95% CI 26.8% to 38.4%) compared with the experience format (MAE=15.9%, 95% CI 11.8% to 20.0%, d =0.697, P<0.001). Likewise, NPV estimation errors were larger in the numerical format (MAE=24.4%, 95% CI 14.5% to 34.3%) than in the experience format (MAE=11.0%, 95% CI 6.5% to 15.5%, d =0.303, P=0.015). Exposure to simulated patient cases promotes accurate estimation of predictive values in clinicians. This finding carries implications for diagnostic training and practice. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  1. Geographic Population Structure in Epstein-Barr Virus Revealed by Comparative Genomics

    PubMed Central

    Chiara, Matteo; Manzari, Caterina; Lionetti, Claudia; Mechelli, Rosella; Anastasiadou, Eleni; Chiara Buscarinu, Maria; Ristori, Giovanni; Salvetti, Marco; Picardi, Ernesto; D’Erchia, Anna Maria; Pesole, Graziano; Horner, David S.

    2016-01-01

    Epstein-Barr virus (EBV) latently infects the majority of the human population and is implicated as a causal or contributory factor in numerous diseases. We sequenced 27 complete EBV genomes from a cohort of Multiple Sclerosis (MS) patients and healthy controls from Italy, although no variants showed a statistically significant association with MS. Taking advantage of the availability of ∼130 EBV genomes with known geographical origins, we reveal a striking geographic distribution of EBV sub-populations with distinct allele frequency distributions. We discuss mechanisms that potentially explain these observations, and their implications for understanding the association of EBV with human disease. PMID:27635051

  2. Employment discrimination implications of genetic screening in the workplace under Title VII and the Rehabilitation Act.

    PubMed

    Canter, E F

    1984-01-01

    The emergence of genetic screening techniques will permit employers to exclude hypersusceptible individuals from potentially hazardous workplace environments. The denial of employment opportunities to these individuals, however, may constitute discrimination. This Note analyzes genetic screening cases with respect to currently available remedies contained in Title VII of the Civil Rights Act of 1964 and the Rehabilitation Act of 1973. The Note concludes that Title VII claims may succeed but only in limited circumstances and that Rehabilitation Act claims will encounter numerous obstacles to relief. Additionally, the Note discusses some of the implications of the use of genetic screening in the workplace.

  3. Numerical simulation of the force generated by a superelastic NiTi orthodontic archwire during tooth alignment phase: comparison between different constitutive models

    NASA Astrophysics Data System (ADS)

    Gannoun, M.; Laroussi Hellara, M.; Bouby, C.; Ben Zineb, T.; Bouraoui, T.

    2018-04-01

    Nickel Titanium (NiTi) Superelastic (SE) Shape Memory Alloys (SMAs) are widely considered for applications that need high reversible strain or high recovery forces. In particular, the SE SMAs present a high interest for biomedical applications such as endodontic and orthodontic apparatus. They are available in a large variety of archwires exerting continuum forces to ensure the dental displacement. The purpose of this study is to report the clinical implications of NiTi SE wires for dental treatment in a given configuration. Three main constitutive models of the literature (Lagoudas and Boyd 1996 Int. J. Plast. 12 805–842, Auricchio and Petrini 2004 Int. J. Numer. Meth. Engng. 61 807–836 and Chemisky et al 2011 Mech. Mater. 68 361–376) are considered for the finite element (FE) numerical simulations of the SMA archwires response. Tensile tests had been carried out in order to identify the material parameters of these constitutive models. The FE numerical study allowed to predict the dental displacement and its corresponding orthodontic force level exerted by the wire in similar conditions to those in the oral environment. This work allows to predict the orthodontic generated load by a NiTi SE archwire with a 0.64 × 0.46 mm2 rectangular cross section under prescribed thermomechanical conditions. The effect of the temperature and the alveolar bone stiffness on the orthodontic load level and the tooth displacement degree has been investigated. The performed numerical simulations demonstrate that the orthodontic load is sensitive to the displacement magnitude, to the tooth stiffness and to the temperature variations. The obtained forces applied continuously and at a constant level are within the acceptable orthodontic force level range. Some directives are therefore provided to help orthodontists to select the optimal archwire.

  4. An investigation of the role of some person and situation variables in multiple cue probability learning.

    PubMed

    Bayindir, Mustafa; Bolger, Fergus; Say, Bilge

    2016-07-19

    Making decisions using judgements of multiple non-deterministic indicators is an important task, both in everyday and professional life. Learning of such decision making has often been studied as the mapping of stimuli (cues) to an environmental variable (criterion); however, little attention has been paid to the effects of situation-by-person interactions on this learning. Accordingly, we manipulated cue and feedback presentation mode (graphic or numeric) and task difficulty, and measured individual differences in working memory capacity (WMC). We predicted that graphic presentation, fewer cues, and elevated WMC would facilitate learning, and that person and task characteristics would interact such that presentation mode compatible with the decision maker's cognitive capability (enhanced visual or verbal WMC) would assist learning, particularly for more difficult tasks. We found our predicted main effects, but no significant interactions, except that those with greater WMC benefited to a larger extent with graphic than with numeric presentation, regardless of which type of working memory was enhanced or number of cues. Our findings suggest that the conclusions of past research based predominantly on tasks using numeric presentation need to be reevaluated and cast light on how working memory helps us learn multiple cue-criterion relationships, with implications for dual-process theories of cognition.

  5. Retrieving the ground state of spin glasses using thermal noise: Performance of quantum annealing at finite temperatures.

    PubMed

    Nishimura, Kohji; Nishimori, Hidetoshi; Ochoa, Andrew J; Katzgraber, Helmut G

    2016-09-01

    We study the problem to infer the ground state of a spin-glass Hamiltonian using data from another Hamiltonian with interactions disturbed by noise from the original Hamiltonian, motivated by the ground-state inference in quantum annealing on a noisy device. It is shown that the average Hamming distance between the inferred spin configuration and the true ground state is minimized when the temperature of the noisy system is kept at a finite value, and not at zero temperature. We present a spin-glass generalization of a well-established result that the ground state of a purely ferromagnetic Hamiltonian is best inferred at a finite temperature in the sense of smallest Hamming distance when the original ferromagnetic interactions are disturbed by noise. We use the numerical transfer-matrix method to establish the existence of an optimal finite temperature in one- and two-dimensional systems. Our numerical results are supported by mean-field calculations, which give an explicit expression of the optimal temperature to infer the spin-glass ground state as a function of variances of the distributions of the original interactions and the noise. The mean-field prediction is in qualitative agreement with numerical data. Implications on postprocessing of quantum annealing on a noisy device are discussed.

  6. Observational Implications of Gamma-Ray Burst Afterglow Jet Simulations and Numerical Light Curve Calculations

    NASA Astrophysics Data System (ADS)

    van Eerten, Hendrik J.; MacFadyen, Andrew I.

    2012-06-01

    We discuss jet dynamics for narrow and wide gamma-ray burst (GRB) afterglow jets and the observational implications of numerical simulations of relativistic jets in two dimensions. We confirm earlier numerical results that sideways expansion of relativistic jets during the bulk of the afterglow emission phase is logarithmic in time and find that this also applies to narrow jets with half opening angle of 0.05 rad. As a result, afterglow jets remain highly nonspherical until after they have become nonrelativistic. Although sideways expansion steepens the afterglow light curve after the jet break, the jet edges becoming visible dominates the jet break, which means that the jet break is sensitive to the observer angle even for narrow jets. Failure to take the observer angle into account can lead to an overestimation of the jet energy by up to a factor of four. This weakens the challenge posed to the magneter energy limit by extreme events such as GRB090926A. Late-time radio calorimetry based on a spherical nonrelativistic outflow model remains relevant when the observer is approximately on-axis and where differences of a few in flux level between the model and the simulation are acceptable. However, this does not imply sphericity of the outflow and therefore does not translate to high observer angles relevant to orphan afterglows. For more accurate calorimetry and in order to model significant late-time features such as the rise of the counterjet, detailed jet simulations remain indispensable.

  7. Confirmatory Factor Analysis of the Trinity Inventory of Precursors to Suicide (TIPS) and Its Relationship to Hopelessness and Depression

    ERIC Educational Resources Information Center

    Smyth, Caroline L.; MacLachlan, Malcolm

    2005-01-01

    Numerous existing measures assess attitudes toward suicide yet fail to account for contextual factors. The Trinity Inventory of Precursors to Suicide (TIPS) is presented as an alternative, with implications for the development of prevention programs. Having previously reported exploratory analysis of the TIPS; confirmatory factor analysis and…

  8. School Referenda in Indiana. Education Policy Brief. Volume 8, Number 2, Summer 2010

    ERIC Educational Resources Information Center

    Hiller, Stephen C.; Spradlin, Terry E.

    2010-01-01

    Past reports by the Center for Evaluation & Education Policy (CEEP) have sought to examine various aspects of Indiana public school funding such as the mechanisms for funding, school revenues and expenditures, as well as numerous other reports whose subjects have implications on school and program funding. This report focuses on another…

  9. Politics of Educational Leadership: Its Implications for Secondary School Improvement in Rivers State

    ERIC Educational Resources Information Center

    Agi, Ugochukwu Kysburn; Kalagbor, Levidoe; Anthony, Harrion

    2016-01-01

    This paper viewed the educational system as a complex whole and a huge endeavour with numerous challenges that have emanated from the dynamic nature of society. The perceived functions of education for a rapidly changing society, has placed enormous pressure on the policy and programmes of education, on the curriculum and the organization and…

  10. LANDSCAPE CHARACTERIZATION & NON-POINT SOURCE NITROGEN MODELING IN SUPPORT OF TMDL DEVELOPMENT IN THE NEUSE RIVER BASIN, NC

    EPA Science Inventory



    Pfesteria-like toxic- blooms have been implicated as the causative agent responsible for numerous outbreaks of fish lesions and fish kills in the Mid-Atlantic and southeastern U.S. An increase in frequency, intensity, and severity of toxic blooms in recent years is though...

  11. U.S. secondary wood manufacturers are becoming larger – are there implications for hardwood sawmills?

    Treesearch

    Matthew Bumgardner; Urs Buehlmann; Omar Espinoza

    2017-01-01

    Previous research has shown that large secondary wood manufacturers request numerous product-related services from their hardwood lumber suppliers. In addition, large secondary manufacturers also source more of their lumber directly from hardwood sawmills than do smaller secondary manufacturers, which tend to purchase more lumber from distributors. Current trends in...

  12. Expanded Roles of Physical Education Teachers within a CSPAP and Implications for PETE

    ERIC Educational Resources Information Center

    Webster, Collin A.; Nesbitt, Danielle

    2017-01-01

    Since the early 1990s, notions about the purpose of physical education (PE) in the United States have increasingly aligned with a public health agenda driven by concerns that youth accrue too little physical activity (PA). In tandem with the shifting tides of thought about PE's purpose, authors have proposed numerous public health-aligned…

  13. Demoralization in Health Professional Practice: Development, Amelioration, and Implications for Continuing Education

    ERIC Educational Resources Information Center

    Gabel, Stewart

    2013-01-01

    Demoralization is a feeling state of dejection, hopelessness, and a sense of personal "incompetence" that may be tied to a loss of or threat to one's own goals or values. It has an existential dimension when beliefs and values about oneself are disconfirmed. Numerous sources describe high rates of dissatisfaction and burnout in…

  14. Hope, Laughter, and Humor in Residents and Staff at an Assisted Living Facility.

    ERIC Educational Resources Information Center

    Westburg, Nancy G.

    2003-01-01

    Assesses and compares hope levels and laughter and humor experiences of 24 elderly residents and 21 staff at an assisted living facility. Residents and staff reported numerous benefits from humor and laughing, but differences arose between the two groups about the source and frequency of humor and laughter. Implications for mental health…

  15. An Examination of Potential Variation in the Benefits of Higher Education for Health and Wellbeing

    ERIC Educational Resources Information Center

    Bauldry, Shawn

    2012-01-01

    Understanding the implications of the significant expansion in higher education over the latter half of the 20th century remains one of the central questions of research in stratification and inequality. Attaining a college degree is associated with numerous advantages ranging from higher earnings to improved health and wellbeing. As higher…

  16. Rightward Biases in Free-Viewing Visual Bisection Tasks: Implications for Leftward Responses Biases on Similar Tasks

    ERIC Educational Resources Information Center

    Elias, Lorin J.; Robinson, Brent; Saucier, Deborah M.

    2005-01-01

    Neurologically normal individuals exhibit strong leftward response biases during free-viewing perceptual judgments of brightness, quantity, and size. When participants view two mirror-reversed objects and they are forced to choose which object appears darker, more numerous, or larger, the stimulus with the relevant feature on the left side is…

  17. Cognitive Development of Adolescents at Risk or with Learning and/or Emotional Problems: Implications for Teachers

    ERIC Educational Resources Information Center

    Watson, Silvana Maria Russo; Gable, Robert

    2013-01-01

    Adolescents face numerous challenges associated with increasing instructional curricular demands at the secondary level. Exacerbating an already difficult time for students with high-incidence disabilities (e.g., learning disabilities, emotional disabilities) is the fact that the majority spend at least some part of the day in general education…

  18. Anthropogenic alterations of genetic diversity within tree populations: Implications for forest ecosystem resilience

    Treesearch

    Paul G. Schaberg; Donald H. DeHayes; Gary J. Hawley; Samuel E. Nijensohn

    2008-01-01

    Healthy forests provide many of the essential ecosystem services upon which all life depends. Genetic diversity is an essential component of long-term forest health because it provides a basis for adaptation and resilience to environmental stress and change. In addition to natural processes, numerous anthropogenic factors deplete forest genetic resources. Genetic...

  19. Mental Health Issues and Nonsuicidal Self-Injury among Youth: Implications for Mental Health Professionals in the School System

    ERIC Educational Resources Information Center

    Schatten, Heather T.; Morris, Blair W.; Wren, Abigail L.; Andover, Margaret S.

    2013-01-01

    Nonsuicidal self-injury (NSSI) is a behavior that is prevalent among children and adolescents. Although NSSI is often associated with borderline personality disorder and depression, it co-occurs with numerous psychiatric symptoms and associated diagnoses. The current article reviews the research addressing psychiatric symptoms that are commonly…

  20. Neurodevelopmental Sequelae of Postnatal Maternal Care in Rodents: Clinical and Research Implications of Molecular Insights

    ERIC Educational Resources Information Center

    Kaffman, Arie; Meaney, Michael J.

    2007-01-01

    Parental care plays an important role in the emotional and cognitive development of the offspring. Children who have been exposed to abuse or neglect are more likely to develop numerous psychopathologies, while good parent-infant bonding is associated with improved resiliency to stress. Similar observations have also been reported in non-human…

  1. Strand IV Environmental and Community Health, Ecology and Epidemiology of Health, Grades 10, 11, and 12.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    A frame of reference concerning health implications, based on the interaction of numerous factors in the physical, social, and biological environments, is provided in this prototype curriculum for grades 10-12. Development of sound techniques in problem solving is encouraged, resulting from the need to understand the nature and complexities of…

  2. The curvilinear effect of work engagement on employees' turnover intentions.

    PubMed

    Caesens, Gaëtane; Stinglhamber, Florence; Marmier, Virginie

    2016-04-01

    Numerous studies have shown the positive consequences of work engagement for both organisations and employees experiencing it. For instance, research has demonstrated that work-engaged employees have lower levels of turnover intentions than non-engaged employees. However, in this research, we examined whether there is a dark side of work engagement. More precisely, we investigated whether the relationship between work engagement and employees' turnover intentions might be non-linear. Based on two different samples, our results indicated that the relationship between work engagement and employees' turnover intentions is curvilinear. The theoretical and practical implications of these results are discussed. © 2014 International Union of Psychological Science.

  3. Resonances at very low temperature for the reaction D2 + H

    NASA Astrophysics Data System (ADS)

    Simbotin, I.; Côté, R.

    2017-05-01

    We present numerical results for rate coefficients of reaction and vibrational quenching in the collision of H with {{{D}}}2(v,j) at cold and ultracold temperatures. We explore both ortho-D{}2(j=0) and para-D{}2(j=1) for several initial vibrational states (v≤slant 5), and find resonant structures in the energy range 0.01-10 K, which are sensitive to the initial rovibrational state (v, j). We compare the reaction rates for D2 + H with our previously obtained results for the isotopologue reaction H2 + D, and discuss the implications of our detailed study of this benchmark system for ultracold chemistry.

  4. Fidelity Study of Superconductivity in Extended Hubbard Models

    NASA Astrophysics Data System (ADS)

    Plonka, Nachum; Jia, Chunjing; Moritz, Brian; Wang, Yao; Devereaux, Thomas

    2015-03-01

    The role of strong electronic correlations on unconventional superconductivity remains an important open question. Here, we explore the influence of long-range Coulomb interactions, present in real material systems, through nearest and next-nearest neighbor extended Hubbard interactions in addition to the usual on-site terms. Utilizing large scale, numerical exact diagonalization, we analyze the signatures of superconductivity in the ground states through the fidelity metric of quantum information theory. We find that these extended interactions enhance charge fluctuations with various wave vectors. These suppress superconductivity in general, but in certain parameter regimes superconductivity is sustained. This has implications for tuning extended interactions in real materials.

  5. Early-Course Unmedicated Schizophrenia Patients Exhibit Elevated Prefrontal Connectivity Associated with Longitudinal Change

    PubMed Central

    Anticevic, Alan; Hu, Xinyu; Xiao, Yuan; Hu, Junmei; Li, Fei; Bi, Feng; Cole, Michael W.; Savic, Aleksandar; Yang, Genevieve J.; Repovs, Grega; Murray, John D.; Wang, Xiao-Jing; Huang, Xiaoqi; Lui, Su; Krystal, John H.

    2015-01-01

    Strong evidence implicates prefrontal cortex (PFC) as a major source of functional impairment in severe mental illness such as schizophrenia. Numerous schizophrenia studies report deficits in PFC structure, activation, and functional connectivity in patients with chronic illness, suggesting that deficient PFC functional connectivity occurs in this disorder. However, the PFC functional connectivity patterns during illness onset and its longitudinal progression remain uncharacterized. Emerging evidence suggests that early-course schizophrenia involves increased PFC glutamate, which might elevate PFC functional connectivity. To test this hypothesis, we examined 129 non-medicated, human subjects diagnosed with early-course schizophrenia and 106 matched healthy human subjects using both whole-brain data-driven and hypothesis-driven PFC analyses of resting-state fMRI. We identified increased PFC connectivity in early-course patients, predictive of symptoms and diagnostic classification, but less evidence for “hypoconnectivity.” At the whole-brain level, we observed “hyperconnectivity” around areas centered on the default system, with modest overlap with PFC-specific effects. The PFC hyperconnectivity normalized for a subset of the sample followed longitudinally (n = 25), which also predicted immediate symptom improvement. Biologically informed computational modeling implicates altered overall connection strength in schizophrenia. The initial hyperconnectivity, which may decrease longitudinally, could have prognostic and therapeutic implications. PMID:25568120

  6. Early-course unmedicated schizophrenia patients exhibit elevated prefrontal connectivity associated with longitudinal change.

    PubMed

    Anticevic, Alan; Hu, Xinyu; Xiao, Yuan; Hu, Junmei; Li, Fei; Bi, Feng; Cole, Michael W; Savic, Aleksandar; Yang, Genevieve J; Repovs, Grega; Murray, John D; Wang, Xiao-Jing; Huang, Xiaoqi; Lui, Su; Krystal, John H; Gong, Qiyong

    2015-01-07

    Strong evidence implicates prefrontal cortex (PFC) as a major source of functional impairment in severe mental illness such as schizophrenia. Numerous schizophrenia studies report deficits in PFC structure, activation, and functional connectivity in patients with chronic illness, suggesting that deficient PFC functional connectivity occurs in this disorder. However, the PFC functional connectivity patterns during illness onset and its longitudinal progression remain uncharacterized. Emerging evidence suggests that early-course schizophrenia involves increased PFC glutamate, which might elevate PFC functional connectivity. To test this hypothesis, we examined 129 non-medicated, human subjects diagnosed with early-course schizophrenia and 106 matched healthy human subjects using both whole-brain data-driven and hypothesis-driven PFC analyses of resting-state fMRI. We identified increased PFC connectivity in early-course patients, predictive of symptoms and diagnostic classification, but less evidence for "hypoconnectivity." At the whole-brain level, we observed "hyperconnectivity" around areas centered on the default system, with modest overlap with PFC-specific effects. The PFC hyperconnectivity normalized for a subset of the sample followed longitudinally (n = 25), which also predicted immediate symptom improvement. Biologically informed computational modeling implicates altered overall connection strength in schizophrenia. The initial hyperconnectivity, which may decrease longitudinally, could have prognostic and therapeutic implications. Copyright © 2015 the authors 0270-6474/15/350267-20$15.00/0.

  7. The implications of selective attrition for estimates of intergenerational elasticity of family income

    PubMed Central

    Schoeni, Robert F.

    2015-01-01

    Numerous studies have estimated a high intergenerational correlation in economic status. Such studies do not typically attend to potential biases that may arise due to survey attrition. Using the Panel Study of Income Dynamics – the data source most commonly used in prior studies – we demonstrate that attrition is particularly high for low-income adult children with low-income parents and particularly low for high-income adult children with high-income parents. Because of this pattern of attrition, intergenerational upward mobility has been overstated for low-income families and downward mobility has been understated for high-income families. The bias among low-income families is greater than the bias among high-income families implying that intergenerational elasticity in family income is higher than previous estimates with the Panel Study of Income Dynamics would suggest. PMID:26251655

  8. Developmental and individual differences in pure numerical estimation.

    PubMed

    Booth, Julie L; Siegler, Robert S

    2006-01-01

    The authors examined developmental and individual differences in pure numerical estimation, the type of estimation that depends solely on knowledge of numbers. Children between kindergarten and 4th grade were asked to solve 4 types of numerical estimation problems: computational, numerosity, measurement, and number line. In Experiment 1, kindergartners and 1st, 2nd, and 3rd graders were presented problems involving the numbers 0-100; in Experiment 2, 2nd and 4th graders were presented problems involving the numbers 0-1,000. Parallel developmental trends, involving increasing reliance on linear representations of numbers and decreasing reliance on logarithmic ones, emerged across different types of estimation. Consistent individual differences across tasks were also apparent, and all types of estimation skill were positively related to math achievement test scores. Implications for understanding of mathematics learning in general are discussed. Copyright 2006 APA, all rights reserved.

  9. Computational Glycobiology: Mechanistic Studies of Carbohydrate-Active Enzymes and Implication for Inhibitor Design.

    PubMed

    Montgomery, Andrew P; Xiao, Kela; Wang, Xingyong; Skropeta, Danielle; Yu, Haibo

    2017-01-01

    Carbohydrate-active enzymes (CAZymes) are families of essential and structurally related enzymes, which catalyze the creation, modification, and degradation of glycosidic bonds in carbohydrates to maintain essentially all kingdoms of life. CAZymes play a key role in many biological processes underpinning human health and diseases (e.g., cancer, diabetes, Alzheimer's diseases, AIDS) and have thus emerged as important drug targets in the fight against pathogenesis. The realization of the full potential of CAZymes remains a significant challenge, relying on a deeper understanding of the molecular mechanisms of catalysis. Considering numerous unsettled questions in the literature, while with a large amount of structural, kinetic, and mutagenesis data available for CAZymes, there is a pressing need and an abundant opportunity for collaborative computational and experimental investigations with the aim to unlock the secrets of CAZyme catalysis at an atomic level. In this review, we briefly survey key methodology development in computational studies of CAZyme catalysis. This is complemented by selected case studies highlighting mechanistic insights provided by computational glycobiology. Implication for inhibitor design by mimicking the transition state is also illustrated for both glycoside hydrolases and glycosyltransferases. The challenges for such studies will be noted and finally an outlook for future directions will be provided. © 2017 Elsevier Inc. All rights reserved.

  10. Current Opinion in Biotechnology: Analytical Biotech

    PubMed Central

    Yannone, Steven M.; Hartung, Sophia; Menon, Angeli L.; Adams, Michael W. W.; Tainer, John A.

    2011-01-01

    The vital nature of metal uptake and balance in biology is evident in the highly evolved strategies to facilitate metal homeostasis in all three domains of life. Several decades of study on metals and metalloproteins have revealed numerous essential bio-metal functions. Recent advances in mass spectrometry, x-ray scattering/absorption, and proteomics have exposed a much broader usage of metals in biology than expected. Even elements such as uranium, arsenic, and lead are implicated in biological processes as part of an emerging and expansive view of bio-metals. Here we discuss opportunities and challenges for established and newer approaches to study metalloproteins with a focus on technologies that promise to rapidly expand our knowledge of metalloproteins and metal functions in biology. PMID:22138493

  11. On the (mis)categorization of unattractive brides and attractive prostitutes: extending evaluative congruency effects to social category activation.

    PubMed

    Ruys, Kirsten I; Dijksterhuis, Ap; Corneille, Olivier

    2008-01-01

    Numerous studies have shown that social categorization is a flexible process that partly depends on contextual variables. However, little is known about the role of affect in people's access to categorical dimensions. We investigated the hypothesis that social category activation is facilitated on evaluatively congruent dimensions. Two studies provide support for this evaluative-matching hypothesis, in which social categorization was found to be faster and more accurate for evaluatively congruent categories (i.e., unattractive foreigners, unattractive prostitutes, attractive fellow-citizens and attractive brides) than for evaluatively incongruent categories (i.e., attractive foreigners, attractive prostitutes, unattractive fellow-citizens and unattractive brides). We discuss the theoretical and practical implications of these findings.

  12. Should visceral fat be reduced to increase longevity?

    PubMed

    Finelli, Carmine; Sommella, Luigi; Gioia, Saverio; La Sala, Nicolina; Tarantino, Giovanni

    2013-09-01

    Several epidemiologic studies have implicated visceral fat as a major risk factor for insulin resistance, type 2 diabetes mellitus, cardiovascular disease, stroke, metabolic syndrome and death. Utilizing novel models of visceral obesity, numerous studies have demonstrated that the relationship between visceral fat and longevity is causal while the accrual of subcutaneous fat does not appear to play an important role in the etiology of disease risk. Specific recommended intake levels vary based on a number of factors, including current weight, activity levels, and weight loss goals. It is discussed the need of reducing the visceral fat as a potential treatment strategy to prevent or delay age-related diseases and to increase longevity. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Running With the Pack: Teen Peer-Relationship Qualities as Predictors of Adult Physical Health

    PubMed Central

    Allen, Joseph P.; Uchino, Bert N.; Hafen, Christopher A.

    2015-01-01

    This study assessed qualities of adolescent peer relationships as long-term predictors of physical health quality in adulthood. In an intensive multimethod, multireporter study of a community sample of 171 individuals assessed repeatedly from the ages of 13 to 27 years, physical health quality in adulthood was robustly predicted by independent reports of early-adolescent close-friendship quality and by a pattern of acquiescence to social norms in adolescent peer relationships. Predictions remained after accounting for numerous potential confounds, including prior health problems, concurrent body mass index, anxious and depressive symptoms, personality characteristics, adolescent-era financial adversity, and adolescent-era physical attractiveness. These findings have important implications for understanding the unique intensity of peer relationships in adolescence. PMID:26290522

  14. Mars: Past, Present, and Future. Results from the MSATT Program, part 1

    NASA Technical Reports Server (NTRS)

    Haberle, R. M. (Editor)

    1993-01-01

    This volume contains papers that were accepted for presentation at the workshop on Mars: Past, Present, and Future -- Results from the MSATT Program. Topics include, but are not limited to: Martian impact craters; thermal emission measurements of Hawaiian palagonitic soils with implications for Mars; thermal studies of the Martian surface; Martian atmospheric composition studies; temporal and spatial mapping of Mars' atmospheric dust opacity and surface albedo; studies of atmospheric dust from Viking IR thermal mapper data; the distribution of Martian ground ice at other epochs; numerical simulation of thermally induced near-surface flows over Martian terrain; the pH of Mars; the mineralogic evolution of the Martian surface through time; geologic controls of erosion and sedimentation on Mars; and dielectric properties of Mars' surface: proposed measurement on a Mars Lander.

  15. Numerical investigation on the implications of spring temperature and discharge rate with respect to the geothermal background in a fault zone

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenjiao; Xu, Tianfu; Mariethoz, Gregoire

    2018-04-01

    Geothermal springs are some of the most obvious indicators of the existence of high-temperature geothermal resources in the subsurface. However, geothermal springs can also occur in areas of low average subsurface temperatures, which makes it difficult to assess exploitable zones. To address this problem, this study quantitatively analyzes the conditions associated with the formation of geothermal springs in fault zones, and numerically investigates the implications that outflow temperature and discharge rate from geothermal springs have on the geothermal background in the subsurface. It is concluded that the temperature of geothermal springs in fault zones is mainly controlled by the recharge rate from the country rock and the hydraulic conductivity in the fault damage zone. Importantly, the topography of the fault trace on the land surface plays an important role in determining the thermal temperature. In fault zones with a permeability higher than 1 mD and a lateral recharge rate from the country rock higher than 1 m3/day, convection plays a dominant role in the heat transport rather than thermal conduction. The geothermal springs do not necessarily occur in the place having an abnormal geothermal background (with the temperature at certain depth exceeding the temperature inferred by the global average continental geothermal gradient of 30 °C/km). Assuming a constant temperature (90 °C here, to represent a normal geothermal background in the subsurface at a depth of 3,000 m), the conditions required for the occurrence of geothermal springs were quantitatively determined.

  16. Changes in tracheid and ray traits in fire scars of North American conifers and their ecophysiological implications

    PubMed Central

    Arbellay, Estelle; Stoffel, Markus; Sutherland, Elaine K.; Smith, Kevin T.; Falk, Donald A.

    2014-01-01

    Background and Aims Fire scars have been widely used as proxies for the reconstruction of fire history; however, little is known about the impact of fire injury on wood anatomy. This study investigates changes in tracheid and ray traits in fire scars of Douglas fir (Pseudotsuga menziesii), western larch (Larix occidentalis) and ponderosa pine (Pinus ponderosa), and discusses their ecophysiological implications for tree recovery from fire. Methods Transverse and tangential microsections were prepared for light microscopy and image analysis. Measurements of tracheids and rays were made in the three spatial dimensions: axially (at different section heights), radially (in different rings) and tangentially (with increasing distance from the wound margin). Key Results Changes were strongest in the first year after fire injury, with a decrease in tracheid size (by 25–30 %) and an increase in tracheid density (by 21–53 %) for the three species. In addition, an increase in ray size (by 5–27 %) and an increase in ray density (by 19–36 %) were found in P. menziesii and L. occidentalis. Changes were comparable along the fire-injured stem and were often most marked close to the fire scar. Conclusions The differentiation after fire injury of narrower and more numerous tracheids expresses a trade-off between hydraulic safety and hydraulic efficiency, while that of larger and more numerous rays serves compartmentalization and wound closure, mechanical strength and defence responses. Pinus ponderosa does not generally produce more ray tissue after fire injury and thus appears to be more adapted to fire. PMID:24941999

  17. Health Safety of Soft Drinks: Contents, Containers, and Microorganisms

    PubMed Central

    2015-01-01

    Soft drinks consumption is still a controversial issue for public health and public policy. Over the years, numerous studies have been conducted into the possible links between soft drink intake and medical problems, the results of which, however, remain highly contested. Nevertheless, as a result, increasing emphasis is being placed on the health properties of soft drinks, by both the industry and the consumers, for example, in the expanding area of functional drinks. Extensive legislation has been put in place to ensure that soft drinks manufacturers conform to established national and international standards. Consumers trust that the soft drinks they buy are safe and their quality is guaranteed. They also expect to be provided with information that can help them to make informed decisions about the purchase of products and that the information on product labels is not false or misleading. This paper provides a broad overview of available scientific knowledge and cites numerous studies on various aspects of soft drinks and their implications for health safety. Particular attention is given to ingredients, including artificial flavorings, colorings, and preservatives and to the lesser known risks of microbiological and chemical contamination during processing and storage. PMID:25695045

  18. Synaptic Plasticity In Mammalian Gravity Sensors: Preliminary Results From SLS-2

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Hargens, Alan R. (Technical Monitor)

    1996-01-01

    Sensory conflict is the prevalent theoretical explanation for space adaptation syndrome. This ultrastructural study tests the hypothesis that peripheral gravity sensors (maculae) play a role. Results were obtained from the medial part of utricular maculae of adult rats exposed to microgravity for 14 days, and from controls. Means and statistical significance of synapse counts were calculated using SUPERANOVA(Trademark) and Scheffe's procedure for post-hoc comparisons. Preliminary findings are from 2 sets of 100 serial sections for each dataset. Synapses were doubled numerically in type II hair cells of utricular maculae collected on day 13 inflight compared to controls (11.4 +/- 7.1 vs. 5.3 +/- 3.8; p < 0.0001). Flight mean synaptic number declined rapidly postflight and became comparable to means of controls. Synapses also increased numerically in type I cells inflight (2.4 +/- 1.6 vs. 1.7 +/- 1.0; p < 0.0341). Postflight there were no significant differences in counts. Results concerning shifts in ribbon type and distribution are also largely replicating previous findings from flight studies. Results indicate that mammalian maculae are adaptive endorgans that retain the property of synaptic plasticity into the adult stage. Macular plasticity has clinical implications for balance disorders of peripheral origin.

  19. Numerical study of the stress state of a deformation twin in magnesium

    DOE PAGES

    Arul Kumar, M.; Kanjarla, A. K.; Niezgoda, S. R.; ...

    2014-11-26

    Here, we present a numerical study of the distribution of the local stress state associated with deformation twinning in Mg, both inside the twinned domain and in its immediate neighborhood, due to the accommodation of the twinning transformation shear. A full-field elastoviscoplastic formulation based on fast Fourier transformation is modified to include the shear transformation strain associated with deformation twinning. We performed two types of twinning transformation simulations with: (i) the twin completely embedded inside a single crystal and (ii) the twin front terminating at a grain boundary. We show that: (a) the resulting stress distribution is more strongly determinedmore » by the shear transformation than by the intragranular character of the twin or the orientation of the neighboring grain; (b) the resolved shear stress on the twin plane along the twin direction is inhomogeneous along the twin–parent interface; and (c) there are substantial differences in the average values of the shear stress in the twin and in the parent grain that contains the twin. We discuss the effect of these local stresses on twin propagation and growth, and the implications of our findings for the modeling of deformation twinning.« less

  20. Regulators of Cholangiocyte Proliferation.

    PubMed

    Hall, Chad; Sato, Keisaku; Wu, Nan; Zhou, Tianhao; Kyritsi, Konstantina; Meng, Fanyin; Glaser, Shannon; Alpini, Gianfranco

    2017-02-10

    Cholangiocytes, a small population of cells within the normal liver, have been the focus of a significant amount of research over the past two decades because of their involvement in cholangiopathies such as primary sclerosing cholangitis and primary biliary cholangitis. This article summarizes landmark studies in the field of cholangiocyte physiology and aims to provide an updated review of biliary pathogenesis. The historical approach of rodent extrahepatic bile duct ligation and the relatively recent utilization of transgenic mice have led to significant discoveries in cholangiocyte pathophysiology. Cholangiocyte physiology is a complex system based on heterogeneity within the biliary tree and a number of signaling pathways that serve to regulate bile composition. Studies have expanded the list of neuropeptides, neurotransmitters, and hormones that have been shown to be key regulators of proliferation and biliary damage. The peptide histamine and hormones, such as melatonin and angiotensin, angiotensin, as well as numerous sex hormones, have been implicated in cholangiocyte proliferation during cholestasis. Numerous pathways promote cholangiocyte proliferation during cholestasis, and there is growing evidence to suggest that cholangiocyte proliferation may promote hepatic fibrosis. These pathways may represent significant therapeutic potential for a subset of cholestatic liver diseases that currently lack effective therapies.

  1. Planet Formation in Binaries

    NASA Astrophysics Data System (ADS)

    Thebault, P.; Haghighipour, N.

    Spurred by the discovery of numerous exoplanets in multiple systems, binaries have become in recent years one of the main topics in planet formation research. Numerous studies have investigated to what extent the presence of a stellar companion can affect the planet formation process. Such studies have implications that can reach beyond the sole context of binaries, as they allow to test certain aspects of the planet formation scenario by submitting them to extreme environments. We review here the current understanding on this complex problem. We show in particular how each of the different stages of the planet-formation process is affected differently by binary perturbations. We focus especially on the intermediate stage of kilometre-sized planetesimal accretion, which has proven to be the most sensitive to binarity and for which the presence of some exoplanets observed in tight binaries is difficult to explain by in-situ formation following the "standard" planet-formation scenario. Some tentative solutions to this apparent paradox are presented. The last part of our review presents a thorough description of the problem of planet habitability, for which the binary environment creates a complex situation because of the presence of two irradation sources of varying distance.

  2. The numerical modeling the sensitivity of coastal wind and ozone concentration to different SST forcing

    NASA Astrophysics Data System (ADS)

    Choi, Hyun-Jung; Lee, Hwa Woon; Jeon, Won-Bae; Lee, Soon-Hwan

    2012-01-01

    This study evaluated an atmospheric and air quality model of the spatial variability in low-level coastal winds and ozone concentration, which are affected by sea surface temperature (SST) forcing with different thermal gradients. Several numerical experiments examined the effect of sea surface SST forcing on the coastal atmosphere and air quality. In this study, the RAMS-CAMx model was used to estimate the sensitivity to two different resolutions of SST forcing during the episode day as well as to simulate the low-level coastal winds and ozone concentration over a complex coastal area. The regional model reproduced the qualitative effect of SST forcing and thermal gradients on the coastal flow. The high-resolution SST derived from NGSST-O (New Generation Sea Surface Temperature Open Ocean) forcing to resolve the warm SST appeared to enhance the mean response of low-level winds to coastal regions. These wind variations have important implications for coastal air quality. A higher ozone concentration was forecasted when SST data with a high resolution was used with the appropriate limitation of temperature, regional wind circulation, vertical mixing height and nocturnal boundary layer (NBL) near coastal areas.

  3. Numerical study of the stress state of a deformation twin in magnesium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arul Kumar, M.; Kanjarla, A. K.; Niezgoda, S. R.

    2015-02-01

    We present here a numerical study of the distribution of the local stress state associated with deformation twinning in Mg, both inside the twinned domain and in its immediate neighborhood, due to the accommodation of the twinning transformation shear. A full-field elastoviscoplastic formulation based on fast Fourier transformation is modified to include the shear transformation strain associated with deformation twinning. We have performed two types of twinning transformation simulations with: (i) the twin completely embedded inside a single crystal and (ii) the twin front terminating at a grain boundary. We show that: (a) the resulting stress distribution is more stronglymore » determined by the shear transformation than by the intragranular character of the twin or the orientation of the neighboring grain; (b) the resolved shear stress on the twin plane along the twin direction is inhomogeneous along the twin–parent interface; and (c) there are substantial differences in the average values of the shear stress in the twin and in the parent grain that contains the twin. We discuss the effect of these local stresses on twin propagation and growth, and the implications of our findings for the modeling of deformation twinning.« less

  4. Criticality of the mean-field spin-boson model: boson state truncation and its scaling analysis

    NASA Astrophysics Data System (ADS)

    Hou, Y.-H.; Tong, N.-H.

    2010-11-01

    The spin-boson model has nontrivial quantum phase transitions at zero temperature induced by the spin-boson coupling. The bosonic numerical renormalization group (BNRG) study of the critical exponents β and δ of this model is hampered by the effects of boson Hilbert space truncation. Here we analyze the mean-field spin boson model to figure out the scaling behavior of magnetization under the cutoff of boson states N b . We find that the truncation is a strong relevant operator with respect to the Gaussian fixed point in 0 < s < 1/2 and incurs the deviation of the exponents from the classical values. The magnetization at zero bias near the critical point is described by a generalized homogeneous function (GHF) of two variables τ = α - α c and x = 1/ N b . The universal function has a double-power form and the powers are obtained analytically as well as numerically. Similarly, m( α = α c ) is found to be a GHF of γ and x. In the regime s > 1/2, the truncation produces no effect. Implications of these findings to the BNRG study are discussed.

  5. Influence of each Zernike aberration on the propagation of laser beams through atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Azarian, Adrian; Gladysz, Szymon

    2014-10-01

    We study the influence of each Zernike mode on the propagation of a laser beam through the atmosphere by two different numerical methods. In the first method, an idealized adaptive optics system is modeled to subtract a certain number of Zernike modes from the beam. The effect of each aberration is quantified using the Strehl ratio of the longterm exposure in target/receiver plane. In the second method, the strength of each Zernike mode is varied using a numerical space-filling design during the generation of the phase screens. The resulting central intensity for each point of the design is then studied by a linear discriminant analysis, which yields to the importance of each Zernike mode. The results of the two methods are consistent. They indicate that, for a focused Gaussian beam and for certain geometries and turbulence strengths, the hypothesis of diminishing gains with correction of each new mode is not true. For such cases, we observe jumps in the calculated criteria, which indicate an increased importance of some particular modes, especially coma. The implications of these results for the design of adaptive optics systems are discussed.

  6. Health safety of soft drinks: contents, containers, and microorganisms.

    PubMed

    Kregiel, Dorota

    2015-01-01

    Soft drinks consumption is still a controversial issue for public health and public policy. Over the years, numerous studies have been conducted into the possible links between soft drink intake and medical problems, the results of which, however, remain highly contested. Nevertheless, as a result, increasing emphasis is being placed on the health properties of soft drinks, by both the industry and the consumers, for example, in the expanding area of functional drinks. Extensive legislation has been put in place to ensure that soft drinks manufacturers conform to established national and international standards. Consumers trust that the soft drinks they buy are safe and their quality is guaranteed. They also expect to be provided with information that can help them to make informed decisions about the purchase of products and that the information on product labels is not false or misleading. This paper provides a broad overview of available scientific knowledge and cites numerous studies on various aspects of soft drinks and their implications for health safety. Particular attention is given to ingredients, including artificial flavorings, colorings, and preservatives and to the lesser known risks of microbiological and chemical contamination during processing and storage.

  7. Systems biology approaches to understand the effects of nutrition and promote health.

    PubMed

    Badimon, Lina; Vilahur, Gemma; Padro, Teresa

    2017-01-01

    Within the last years the implementation of systems biology in nutritional research has emerged as a powerful tool to understand the mechanisms by which dietary components promote health and prevent disease as well as to identify the biologically active molecules involved in such effects. Systems biology, by combining several '-omics' disciplines (mainly genomics/transcriptomics, proteomics and metabolomics), creates large data sets that upon computational integration provide in silico predictive networks that allow a more extensive analysis of the individual response to a nutritional intervention and provide a more global comprehensive understanding of how diet may influence health and disease. Numerous studies have demonstrated that diet and particularly bioactive food components play a pivotal role in helping to counteract environmental-related oxidative damage. Oxidative stress is considered to be strongly implicated in ageing and the pathophysiology of numerous diseases including neurodegenerative disease, cancers, metabolic disorders and cardiovascular diseases. In the following review we will provide insights into the role of systems biology in nutritional research and focus on transcriptomic, proteomic and metabolomics studies that have demonstrated the ability of functional foods and their bioactive components to fight against oxidative damage and contribute to health benefits. © 2016 The British Pharmacological Society.

  8. PKCδ-mediated phosphorylation of BAG3 at Ser187 site induces epithelial-mesenchymal transition and enhances invasiveness in thyroid cancer FRO cells.

    PubMed

    Li, N; Du, Z-X; Zong, Z-H; Liu, B-Q; Li, C; Zhang, Q; Wang, H-Q

    2013-09-19

    Protein kinase C delta (PKCδ) is a serine (Ser)/threonine kinase, which regulates numerous cellular processes, including proliferation, differentiation, migration and apoptosis. In the current study, Chinese hamster ovary cells were transfected with either a constitutively activated PKCδ or a dominant negative PKCδ, phosphoprotein enrichment, two-dimensional difference gel electrophoresis and mass spectrometry was combined to globally identified candidates of PKCδ cascade. We found that Bcl-2 associated athanogene 3 (BAG3) was one of the targets of PKCδ cascade, and BAG3 interacted with PKCδ in vivo. In addition, we clarified that BAG3 was phosphorylate at Ser187 site in a PKCδ-dependent manner in vivo. BAG3 has been implicated in multiple cellular functions, including proliferation, differentiation, apoptosis, migration, invasion, macroautophagy and so on. We generated wild-type (WT)-, Ser187Ala (S187A)- or Ser187Asp (S187D)-BAG3 stably expressing FRO cells, and noticed that phosphorylation state of BAG3 influenced FRO morphology. Finally, for the first time, we showed that BAG3 was implicated in epithelial-mesenchymal transition (EMT) procedure, and phosphorylation state at Ser187 site had a critical role in EMT regulation by BAG3. Collectively, the current study indicates that BAG3 is a novel substrate of PKCδ, and PKCδ-mediated phosphorylation of BAG3 is implicated in EMT and invasiveness of thyroid cancer cells.

  9. Sex differences in the implications of partner physical attractiveness for the trajectory of marital satisfaction.

    PubMed

    Meltzer, Andrea L; McNulty, James K; Jackson, Grace L; Karney, Benjamin R

    2014-03-01

    Do men value physical attractiveness in a mate more than women? Scientists in numerous disciplines believe that they do, but recent research using speed-dating paradigms suggests that males and females are equally influenced by physical attractiveness when choosing potential mates. Nevertheless, the premise of the current work is that sex differences in the importance of physical attractiveness are most likely to emerge in research on long-term relationships. Accordingly, the current work drew from 4 independent, longitudinal studies to examine sex differences in the implications of partner physical attractiveness for trajectories of marital satisfaction. In all 4 studies, both partners' physical attractiveness was objectively rated at baseline, and both partners reported their marital satisfaction up to 8 times over the first 4 years of marriage. Whereas husbands were more satisfied at the beginning of the marriage and remained more satisfied over the next 4 years to the extent that they had an attractive wife, wives were no more or less satisfied initially or over the next 4 years to the extent that they had an attractive husband. Most importantly, a direct test indicated that partner physical attractiveness played a larger role in predicting husbands' satisfaction than predicting wives' satisfaction. These findings strengthen support for the idea that sex differences in self-reported preferences for physical attractiveness do have implications for long-term relationship outcomes. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  10. Implications of managing the timing and intensity of herbivory for conservation of Arizona leatherflower

    Treesearch

    Joyce Maschinski

    2001-01-01

    For rare plants, the question of whether and to what extent wild and domestic herbivores influence growth, reproduction, and survival can be critical to preservation. The sensitive species, Clematis hirsutissima var. arizonica, grows on Forest Service lands where cattle, elk, mule deer, and numerous small mammals forage. In a 3-year clipping experiment, I examined the...

  11. Field Dependence-Independence as Visuospatial and Executive Functioning in Working Memory: Implications for Instructional Systems Design and Research

    ERIC Educational Resources Information Center

    Rittschof, Kent A.

    2010-01-01

    Field dependence-independence (FDI) has long been conceptualized and discussed as a cognitive style relevant to numerous educational approaches and outcomes. However, the FDI construct is most often measured as a cognitive ability, as opposed to a style, using instruments such as the Group-Embedded Figures test (GEFT) or the Hidden Figures Test…

  12. Managing and Mobilising Talent in Malaysia: Issues, Challenges and Policy Implications for Malaysian Universities

    ERIC Educational Resources Information Center

    Azman, Norzaini; Sirat, Morshidi; Pang, Vincent

    2016-01-01

    The future of Malaysia as a high-income and competitive nation largely depends on its pool of highly skilled human capital. Hence, the issue of human capital development has taken centre stage in numerous reform agendas of Malaysia. This paper seeks to provide examples of policy initiatives aimed at facilitating the management of highly educated…

  13. Seventy years of understory development by elevation class in a New Hampshire mixed forest: management implications

    Treesearch

    William B. Leak

    2009-01-01

    New England forest managers are faced with numerous environmental issues, such as global warming, nutrient depletion, and species declines that could influence the choice of appropriate silvicultural techniques and objectives. On the Bartlett Experimental Forest, New Hampshire, 70 years of change on more than 400 remeasured cruise plots by elevation classes ranging...

  14. Utilization implications for hardwoods susceptible to sudden oak death

    Treesearch

    John R. Shelly

    2002-01-01

    The number of woody species succumbing to Sudden Oak Death (SOD) infections and the number of counties where the pathogen has been reported continue to increase. One result is that the hazards related to falling trees and high levels of fuel hazard conditions are also increasing dramatically. The removal of infected, dead and dying trees creates numerous handling and...

  15. Purinergic P2X(7) receptor antagonists: Chemistry and fundamentals of biological screening.

    PubMed

    Gunosewoyo, Hendra; Coster, Mark J; Bennett, Maxwell R; Kassiou, Michael

    2009-07-15

    The purinergic P2X(7) receptor is a unique member of the ATP-gated P2X family. This receptor has been implicated in numerous diseases and many structurally diverse ligands have been discovered via high throughput screening. This perspective will attempt to highlight some of the most recent key findings in both the biology and chemistry.

  16. Emerging issues in urban ecology: implications for research, social justice, human health, and well-being

    Treesearch

    Viniece Jennings; Myron F. Floyd; Danielle Shanahan; Christopher Coutts; Alex Sinykin

    2017-01-01

    Urbanization affects landscape structure and the overall human condition in numerous ways. Green spaces include vegetated land cover (e.g., urban forests, trees, riparian zones, parks) which play a distinctive role in urban ecology. This article reviews emergent literature on the linkages between urban green spaces, social justice, and human health. We explore this...

  17. Progress in the Use of Rapid Molecular Techniques to Detect Life Forms in Soil: Implications for Interplanetary Astrobiology Missions

    NASA Technical Reports Server (NTRS)

    Warmflash, D.; Larios-Sanz, M.; Fox, G. E.; McKay, D. S.

    2002-01-01

    To demonstrate the feasibility of two promising technologies, we have applied Enzyme-Linked Immunosorbent Assay (ELISA) as well as probes that target the 16S rRNA molecule to search for life in terrestrial soil samples, known to contain numerous life forms. Additional information is contained in the original extended abstract.

  18. Pesticide use within a pollinator-dependent crop has negative effects on the abundance and species richness of sweat bees, Lasioglossum spp., and on bumble bee colony growth.

    USDA-ARS?s Scientific Manuscript database

    Pesticides are implicated in current bee declines. Wild bees that nest or forage within agroecosystems may be exposed to numerous pesticides applied throughout their life cycles, with potential additive or synergistic effects. In pollinator-dependent crops, pesticides may reduce bee populations, cre...

  19. Leafcutter bee nests and pupae from the Rancho La Brea Tar Pits of southern California: Implications for understanding the paleoenvironment of the Late Pleistocene

    USDA-ARS?s Scientific Manuscript database

    The Rancho La Brea Tar Pits is the world’s richest and most important Late Pleistocene fossil locality and best renowned for numerous fossil mammals and birds excavated over the past century. Less researched are insects, even though these specimens frequently serve as the most valuable paleoenvironm...

  20. On the formation and persistence of superfog in woodland smoke

    Treesearch

    G.L. Achtemeier

    2009-01-01

    Dense fogs, comparable to historical fogs in England, have been implicated in numerous roadway accidents in the southern United States. Many of the fogs have occurred in association with prescribed burning. Direct measurements of superfog (fog reducing visibility to less than 3 m) were taken during burning of forest litter on 22 March 2003. Visibility was measured at 0...

  1. Comparison of the growth of Escherichia coli O157: H7 and O104: H4 during sprouting and microgreen production from contaminated radish seeds

    USDA-ARS?s Scientific Manuscript database

    Both sprouts and microgreens are popular tender produce items, typically grown and harvested in indoor facilities which allow a higher degree of control compared to open field production. While sprouts, which have frequently been implicated in foodborne illness outbreaks, are the subject of numerous...

  2. On the formation and persistence of superfog in woodland smoke

    Treesearch

    Gary L. Achtemeier

    2009-01-01

    Dense fogs. comparable to historical fogs in England, have been implicated in numerous roadway accidents in the southern United States. Many of the fogs have occurred in association with prescribed burning. Direct measurements of superfog (fog reducing visibility to less than 3 rn) were taken during burning of forest litter on 22 March 2003. Visibility was measured at...

  3. Conductivity through Polymer Electrolytes and Its Implications in Lithium-Ion Batteries: Real-World Application of Periodic Trends

    ERIC Educational Resources Information Center

    Compton, Owen C.; Egan, Martin; Kanakaraj, Rupa; Higgins, Thomas B.; Nguyen, SonBinh T.

    2012-01-01

    Periodic conductivity trends are placed in the scope of lithium-ion batteries, where increases in the ionic radii of salt components affect the conductivity of a poly(ethyleneoxide)-based polymer electrolyte. Numerous electrolytes containing varying concentrations and types of metal salts are prepared and evaluated in either one or two laboratory…

  4. Detergent-Based Isolation of Yeast Membrane Rafts: An Inquiry-Based Laboratory Series for the Undergraduate Cell Biology or Biochemistry Lab

    ERIC Educational Resources Information Center

    Willhite, D. Grant; Wright, Stephen E.

    2009-01-01

    Lipid rafts have been implicated in numerous cellular processes including cell signaling, endocytosis, and even viral infection. Isolation of these lipid rafts often involves detergent treatment of the membrane to dissolve nonraft components followed by separation of raft regions in a density gradient. We present here an inquiry-based lab series…

  5. The Departure Status of Youth from Residential Group Care: Implications for Aftercare

    ERIC Educational Resources Information Center

    Trout, Alexandra L.; Chmelka, M. Beth; Thompson, Ronald W.; Epstein, Michael H.; Tyler, Patrick; Pick, Robert

    2010-01-01

    Youth departing from out-of-home care settings face numerous challenges as they adapt to new settings or return to placements that have been unsuccessful in the past. Although several thousand youth face this transition annually, little is known about their specific needs and risks at departure. To better identify needs and risks, we evaluated the…

  6. AIDS: medicolegal considerations for Canadian hospitals.

    PubMed Central

    Johnson, B J; Soskolne, C L

    1986-01-01

    Given the increasing endemicity of human immunodeficiency virus (HIV), the agent implicated in the causation of acquired immune deficiency syndrome (AIDS), in numerous sizeable subgroups of society, hospitals can expect increasing exposure to the legal implications presented by patients with AIDS. This paper reviews the duty of care owed by hospitals, both directly, through contractual obligations, and indirectly, through the acts of their employees and private contractors, to patients with AIDS, other patients and the public. Owing to the absence of case law directly related to AIDS or to HIV antibody reactivity, inferences were drawn from precedents set with other infectious diseases. Recommendations are made in the areas of confidentiality, informed consent, standards of care and vicarious liability. PMID:3464340

  7. AIDS: medicolegal considerations for Canadian hospitals.

    PubMed

    Johnson, B J; Soskolne, C L

    1986-11-15

    Given the increasing endemicity of human immunodeficiency virus (HIV), the agent implicated in the causation of acquired immune deficiency syndrome (AIDS), in numerous sizeable subgroups of society, hospitals can expect increasing exposure to the legal implications presented by patients with AIDS. This paper reviews the duty of care owed by hospitals, both directly, through contractual obligations, and indirectly, through the acts of their employees and private contractors, to patients with AIDS, other patients and the public. Owing to the absence of case law directly related to AIDS or to HIV antibody reactivity, inferences were drawn from precedents set with other infectious diseases. Recommendations are made in the areas of confidentiality, informed consent, standards of care and vicarious liability.

  8. Unconscious Desire: The Affective and Motivational Aspects of Subliminal Sexual Priming.

    PubMed

    Gillath, Omri; Collins, Tara

    2016-01-01

    Sexual arousal is thought to be the result of the processing of sexual cues at two levels: conscious and unconscious. Whereas numerous studies have examined the affective and motivational responses to supraliminal (consciously processed) sexual cues, much less is known regarding the responses to subliminal (processed outside of one's awareness) sexual cues. Five studies examined responses to subliminal sexual cues. Studies 1–3 demonstrated increases in adults' positive affect following exposure to subliminal sexual cues compared to control cues. Study 4 demonstrated that the positive affect resulting from exposure to subliminal sexual cues increased motivation to further engage in a neutral task. Study 5 provided evidence suggesting that the affect and motivation found in Studies 1–4 were associated with motivation to engage in sex specifically, rather than a general approach motivation. The implications of these findings for the processing of subliminal sexual cues and for human sexuality are discussed.

  9. Upward movement of plutonium to surface sediments during an 11-year field study.

    PubMed

    Kaplan, D I; Demirkanli, D I; Molz, F J; Beals, D M; Cadieux, J R; Halverson, J E

    2010-05-01

    An 11-year lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The (240)Pu/(239)Pu and (242)Pu/(239)Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  10. Representational change and strategy use in children's number line estimation during the first years of primary school.

    PubMed

    White, Sonia L J; Szűcs, Dénes

    2012-01-04

    The objective of this study was to scrutinize number line estimation behaviors displayed by children in mathematics classrooms during the first three years of schooling. We extend existing research by not only mapping potential logarithmic-linear shifts but also provide a new perspective by studying in detail the estimation strategies of individual target digits within a number range familiar to children. Typically developing children (n = 67) from Years 1-3 completed a number-to-position numerical estimation task (0-20 number line). Estimation behaviors were first analyzed via logarithmic and linear regression modeling. Subsequently, using an analysis of variance we compared the estimation accuracy of each digit, thus identifying target digits that were estimated with the assistance of arithmetic strategy. Our results further confirm a developmental logarithmic-linear shift when utilizing regression modeling; however, uniquely we have identified that children employ variable strategies when completing numerical estimation, with levels of strategy advancing with development. In terms of the existing cognitive research, this strategy factor highlights the limitations of any regression modeling approach, or alternatively, it could underpin the developmental time course of the logarithmic-linear shift. Future studies need to systematically investigate this relationship and also consider the implications for educational practice.

  11. Representational change and strategy use in children's number line estimation during the first years of primary school

    PubMed Central

    2012-01-01

    Background The objective of this study was to scrutinize number line estimation behaviors displayed by children in mathematics classrooms during the first three years of schooling. We extend existing research by not only mapping potential logarithmic-linear shifts but also provide a new perspective by studying in detail the estimation strategies of individual target digits within a number range familiar to children. Methods Typically developing children (n = 67) from Years 1-3 completed a number-to-position numerical estimation task (0-20 number line). Estimation behaviors were first analyzed via logarithmic and linear regression modeling. Subsequently, using an analysis of variance we compared the estimation accuracy of each digit, thus identifying target digits that were estimated with the assistance of arithmetic strategy. Results Our results further confirm a developmental logarithmic-linear shift when utilizing regression modeling; however, uniquely we have identified that children employ variable strategies when completing numerical estimation, with levels of strategy advancing with development. Conclusion In terms of the existing cognitive research, this strategy factor highlights the limitations of any regression modeling approach, or alternatively, it could underpin the developmental time course of the logarithmic-linear shift. Future studies need to systematically investigate this relationship and also consider the implications for educational practice. PMID:22217191

  12. Natural frequencies facilitate diagnostic inferences of managers

    PubMed Central

    Hoffrage, Ulrich; Hafenbrädl, Sebastian; Bouquet, Cyril

    2015-01-01

    In Bayesian inference tasks, information about base rates as well as hit rate and false-alarm rate needs to be integrated according to Bayes’ rule after the result of a diagnostic test became known. Numerous studies have found that presenting information in a Bayesian inference task in terms of natural frequencies leads to better performance compared to variants with information presented in terms of probabilities or percentages. Natural frequencies are the tallies in a natural sample in which hit rate and false-alarm rate are not normalized with respect to base rates. The present research replicates the beneficial effect of natural frequencies with four tasks from the domain of management, and with management students as well as experienced executives as participants. The percentage of Bayesian responses was almost twice as high when information was presented in natural frequencies compared to a presentation in terms of percentages. In contrast to most tasks previously studied, the majority of numerical responses were lower than the Bayesian solutions. Having heard of Bayes’ rule prior to the study did not affect Bayesian performance. An implication of our work is that textbooks explaining Bayes’ rule should teach how to represent information in terms of natural frequencies instead of how to plug probabilities or percentages into a formula. PMID:26157397

  13. Multiple pathogenic proteins implicated in neuronopathic Gaucher disease mice.

    PubMed

    Xu, You-hai; Xu, Kui; Sun, Ying; Liou, Benjamin; Quinn, Brian; Li, Rong-hua; Xue, Ling; Zhang, Wujuan; Setchell, Kenneth D R; Witte, David; Grabowski, Gregory A

    2014-08-01

    Gaucher disease, a prevalent lysosomal storage disease (LSD), is caused by insufficient activity of acid β-glucosidase (GCase) and the resultant glucosylceramide (GC)/glucosylsphingosine (GS) accumulation in visceral organs (Type 1) and the central nervous system (Types 2 and 3). Recent clinical and genetic studies implicate a pathogenic link between Gaucher and neurodegenerative diseases. The aggregation and inclusion bodies of α-synuclein with ubiquitin are present in the brains of Gaucher disease patients and mouse models. Indirect evidence of β-amyloid pathology promoting α-synuclein fibrillation supports these pathogenic proteins as a common feature in neurodegenerative diseases. Here, multiple proteins are implicated in the pathogenesis of chronic neuronopathic Gaucher disease (nGD). Immunohistochemical and biochemical analyses showed significant amounts of β-amyloid and amyloid precursor protein (APP) aggregates in the cortex, hippocampus, stratum and substantia nigra of the nGD mice. APP aggregates were in neuronal cells and colocalized with α-synuclein signals. A majority of APP co-localized with the mitochondrial markers TOM40 and Cox IV; a small portion co-localized with the autophagy proteins, P62/LC3, and the lysosomal marker, LAMP1. In cultured wild-type brain cortical neural cells, the GCase-irreversible inhibitor, conduritol B epoxide (CBE), reproduced the APP/α-synuclein aggregation and the accumulation of GC/GS. Ultrastructural studies showed numerous larger-sized and electron-dense mitochondria in nGD cerebral cortical neural cells. Significant reductions of mitochondrial adenosine triphosphate production and oxygen consumption (28-40%) were detected in nGD brains and in CBE-treated neural cells. These studies implicate defective GCase function and GC/GS accumulation as risk factors for mitochondrial dysfunction and the multi-proteinopathies (α-synuclein-, APP- and Aβ-aggregates) in nGD. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Teaching Mathematical Modelling for Earth Sciences via Case Studies

    NASA Astrophysics Data System (ADS)

    Yang, Xin-She

    2010-05-01

    Mathematical modelling is becoming crucially important for earth sciences because the modelling of complex systems such as geological, geophysical and environmental processes requires mathematical analysis, numerical methods and computer programming. However, a substantial fraction of earth science undergraduates and graduates may not have sufficient skills in mathematical modelling, which is due to either limited mathematical training or lack of appropriate mathematical textbooks for self-study. In this paper, we described a detailed case-study-based approach for teaching mathematical modelling. We illustrate how essential mathematical skills can be developed for students with limited training in secondary mathematics so that they are confident in dealing with real-world mathematical modelling at university level. We have chosen various topics such as Airy isostasy, greenhouse effect, sedimentation and Stokes' flow,free-air and Bouguer gravity, Brownian motion, rain-drop dynamics, impact cratering, heat conduction and cooling of the lithosphere as case studies; and we use these step-by-step case studies to teach exponentials, logarithms, spherical geometry, basic calculus, complex numbers, Fourier transforms, ordinary differential equations, vectors and matrix algebra, partial differential equations, geostatistics and basic numeric methods. Implications for teaching university mathematics for earth scientists for tomorrow's classroom will also be discussed. Refereces 1) D. L. Turcotte and G. Schubert, Geodynamics, 2nd Edition, Cambridge University Press, (2002). 2) X. S. Yang, Introductory Mathematics for Earth Scientists, Dunedin Academic Press, (2009).

  15. Economic Assessment of Correlated Energy-Water Impacts using Computable General Equilibrium Modeling

    NASA Astrophysics Data System (ADS)

    Qiu, F.; Andrew, S.; Wang, J.; Yan, E.; Zhou, Z.; Veselka, T.

    2016-12-01

    Many studies on energy and water are rightfully interested in the interaction of water and energy, and their projected dependence into the future. Water is indeed an essential input to the power sector currently, and energy is required to pump water for end use in either household consumption or in industrial uses. However, each presented study either qualitatively discusses the issues, particularly about how better understanding the interconnectedness of the system is paramount in getting better policy recommendations, or considers a partial equilibrium framework where water use and energy use changes are considered explicitly without thought to other repercussions throughout the regional/national/international economic landscapes. While many studies are beginning to ask the right questions, the lack of numerical rigor raises questions of concern in conclusions discerned. Most use life cycle analysis as a method for providing numerical results, though this lacks the flexibility that economics can provide. In this study, we will perform economic analysis using computable general equilibrium models with energy-water interdependencies captured as an important factor. We atempt to answer important and interesting questions in the studies: how can we characterize the economic choice of energy technology adoptions and their implications on water use in the domestic economy. Moreover, given predictions of reductions in rain fall in the near future, how does this impact the water supply in the midst of this energy-water trade-off?

  16. Finite element modeling of contaminant transport in soils including the effect of chemical reactions.

    PubMed

    Javadi, A A; Al-Najjar, M M

    2007-05-17

    The movement of chemicals through soils to the groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. Recent studies have shown that the current models and methods are not able to adequately describe the leaching of nutrients through soils, often underestimating the risk of groundwater contamination by surface-applied chemicals, and overestimating the concentration of resident solutes. Furthermore, the effect of chemical reactions on the fate and transport of contaminants is not included in many of the existing numerical models for contaminant transport. In this paper a numerical model is presented for simulation of the flow of water and air and contaminant transport through unsaturated soils with the main focus being on the effects of chemical reactions. The governing equations of miscible contaminant transport including advection, dispersion-diffusion and adsorption effects together with the effect of chemical reactions are presented. The mathematical framework and the numerical implementation of the model are described in detail. The model is validated by application to a number of test cases from the literature and is then applied to the simulation of a physical model test involving transport of contaminants in a block of soil with particular reference to the effects of chemical reactions. Comparison of the results of the numerical model with the experimental results shows that the model is capable of predicting the effects of chemical reactions with very high accuracy. The importance of consideration of the effects of chemical reactions is highlighted.

  17. Supplementary motor area as key structure for domain-general sequence processing: A unified account.

    PubMed

    Cona, Giorgia; Semenza, Carlo

    2017-01-01

    The Supplementary Motor Area (SMA) is considered as an anatomically and functionally heterogeneous region and is implicated in several functions. We propose that SMA plays a crucial role in domain-general sequence processes, contributing to the integration of sequential elements into higher-order representations regardless of the nature of such elements (e.g., motor, temporal, spatial, numerical, linguistic, etc.). This review emphasizes the domain-general involvement of the SMA, as this region has been found to support sequence operations in a variety of cognitive domains that, albeit different, share an inherent sequence processing. These include action, time and spatial processing, numerical cognition, music and language processing, and working memory. In this light, we reviewed and synthesized recent neuroimaging, stimulation and electrophysiological studies in order to compare and reconcile the distinct sources of data by proposing a unifying account for the role of the SMA. We also discussed the differential contribution of the pre-SMA and SMA-proper in sequence operations, and possible neural mechanisms by which such operations are executed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Observing mergers of nonspinning black-hole binaries

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McWilliams, Sean T.; Baker, John G.; Kelly, Bernard J.

    2010-07-15

    Advances in the field of numerical relativity now make it possible to calculate the final, most powerful merger phase of binary black-hole coalescence for generic binaries. The state of the art has advanced well beyond the equal-mass case into the unequal-mass and spinning regions of parameter space. We present a study of the nonspinning portion of parameter space, primarily using an analytic waveform model tuned to available numerical data, with an emphasis on observational implications. We investigate the impact of varied mass-ratio on merger signal-to-noise ratios for several detectors, and compare our results with expectations from the test-mass limit. Wemore » note a striking similarity of the waveform phasing of the merger waveform across the available mass ratios. Motivated by this, we calculate the match between our 1:1 (equal-mass) and 4:1 mass-ratio waveforms during the merger as a function of location on the source sky, using a new formalism for the match that accounts for higher harmonics. This is an indicator of the amount of degeneracy in mass-ratio for mergers of moderate-mass-ratio systems.« less

  19. Density Anomalies in the Mantle and the Gravitational Core-Mantle Interaction

    NASA Technical Reports Server (NTRS)

    Kuang, Weijia; Liu, Lanbo

    2003-01-01

    Seismic studies suggest that the bulk of the mantle is heterogeneous, with density variations in depth as well as in horizontal directions (latitude and longitude). This density variation produces a three- dimensional gravity field throughout the Earth. On the other hand, the core density also varies in both time and space, due to convective core flow. Consequently, the fluid outer core and the solid mantle interact gravitationally due to the mass anomalies in both regions. This gravitational core-mantle interaction could play a significant role in exchange of angular momentum between the core and the mantle, and thus the change in Earth's rotation on time scales of decades and longer. Aiming at estimating the significance of the gravitational core-mantle interaction on Earth's rotation variation, we introduce in our MoSST core dynamics model a heterogeneous mantle, with a density distribution derived from seismic results. In this model, the core convection is driven by the buoyancy forces. And the density variation is determined dynamically with the convection. Numerical simulation is carried out with different parameter values, intending to extrapolate numerical results for geophysical implications.

  20. Intestinal Lymphatic Transport: an Overlooked Pathway for Understanding Absorption of Plant Secondary Compounds in Vertebrate Herbivores.

    PubMed

    Kohl, Kevin D; Dearing, M Denise

    2017-03-01

    Herbivores employ numerous strategies to reduce their exposure to toxic plant secondary chemicals (PSCs). However, the physiological mechanisms of PSC absorption have not been extensively explored. In particular, the absorption of PSCs via intestinal lymphatic absorption has been largely overlooked in herbivores, even though this pathway is well recognized for pharmaceutical uptake. Here, we investigated for the first time whether PSCs might be absorbed by lymphatic transport. We fed woodrats (Neotoma albigula) diets with increasing concentrations of terpene-rich juniper (Juniperus monosperma) either with or without a compound that blocks intestinal lymphatic absorption (Pluronic L-81). Woodrats consuming diets that contained the intestinal lymphatic absorption blocker exhibited increased food intakes and maintained higher body masses on juniper diets. Our study represents the first demonstration that PSCs may be absorbed by intestinal lymphatic absorption. This absorption pathway has numerous implications for the metabolism and distribution of PSCs in the systemic circulation, given that compounds absorbed via lymphatic transport bypass first-pass hepatic metabolism. The area of lymphatic transport of PSCs represents an understudied physiological pathway in plant-herbivore interactions.

  1. Numbers in Action.

    PubMed

    Rugani, Rosa; Sartori, Luisa

    2016-01-01

    Humans show a remarkable tendency to describe and think of numbers as being placed on a mental number line (MNL), with smaller numbers located on the left and larger ones on the right. Faster responses to small numbers are indeed performed on the left side of space, while responses to large numbers are facilitated on the right side of space (spatial-numerical association of response codes, SNARC effect). This phenomenon is considered the experimental demonstration of the MNL and has been extensively replicated throughout a variety of paradigms. Nevertheless, the majority of previous literature has mainly investigated this effect by means of response times and accuracy, whereas studies considering more subtle and automatic measures such as kinematic parameters are rare (e.g., in a reaching-to-grasp movement, the grip aperture is enlarged in responding to larger numbers than in responding to small numbers). In this brief review we suggest that numerical magnitude can also affect the what and how of action execution (i.e., temporal and spatial components of movement). This evidence could have large implications in the strongly debated issue concerning the effect of experience and culture on the orientation of MNL.

  2. Observing Mergers of Non-Spinning Black-Hole Binaries

    NASA Technical Reports Server (NTRS)

    McWilliams, Sean T.; Boggs, William D.; Baker, John G.; Kelly, Bernard J.

    2010-01-01

    Advances in the field of numerical relativity now make it possible to calculate the final, most powerful merger phase of binary black-hole coalescence for generic binaries. The state of the art has advanced well beyond the equal-mass case into the unequal-mass and spinning regions of parameter space. We present a study of the nonspinning portion of parameter space, primarily using an analytic waveform model tuned to available numerical data, with an emphasis on observational implications. We investigate the impact of varied m8BS ratio on merger signal-to-noise ratios (SNR) for several detectors, and compare our results with expectations from the test-mass limit. We note a striking similarity of the waveform phasing of the merger waveform across the available mass ratios. Motivated by this, we calculate the match between our equal-mass and 4:1 mass-ratio waveforms during the merger as a function of location on the source sky, using a new formalism for the match that accounts for higher harmonics. This is an indicator of the amount of degeneracy in mass ratio for mergers of moderate mass ratio systems.

  3. The Ionization History of The Intergalactic Medium:

    NASA Technical Reports Server (NTRS)

    Madau, Piero

    2003-01-01

    The funded project seeked a unified description of the ionization, physical structure, and evolution of the intergalactic medium (IGM) and quasar intervening absorption systems. We proposed to conduct theoretical studies of the IGM and QSO absorbers in the context of current theories of galaxy formation, developing and using numerical and analytical techniques aimed at a detailed modeling of cosmological radiative transfer, gas dynamics, and thermal and ionization evolution. The ionization history of the IGM has important implications for the metagalactic UV background, intergalactic helium absorption 21-cm tomography, metal absorption systems, fluctuations in the microwave background, and the cosmic rate of structure and star formation. All the original objectives of our program have been achieved, and the results widely used and quoted by the community. Indeed, they remain relevant as the level and complexity of research in this area has increased substantially since our proposal was submitted, due to new discoveries on galaxy formation and evolution, a flood of high-quality data on the distant universe, new theoretical ideas and direct numerical simulations of structure formation in hierarchical clustering theories.

  4. Gaps in college biology students' understanding of photosynthesis: Implications for human constructivist learning theory and college classroom practice

    NASA Astrophysics Data System (ADS)

    Griffard, Phyllis Baudoin

    1999-11-01

    The main research question of this study was: What gaps in biochemical understanding are revealed by a range of university introductory biology students as they work through a critically acclaimed multimedia program on photosynthesis, and what are the corresponding implications for elaboration of the Ausubel-Novak-Gowin Learning Theory (ANG, now Human Constructivism)? Twelve students, mixed for ability, gender and ethnicity, were recruited from two sections of "Bio 101." Before and after instruction in photosynthesis, in-depth clinical interviews were conducted during which participants completed a range of cognitive tasks such as sorting, concept mapping, explaining and predicting. Some tasks involved interacting with a computer simulation of photosynthesis. This study primarily employed qualitative case study and verbal analysis methods. Verbal analysis of the clinical interviews revealed numerous gaps that were categorized into typologies. The two major categories were propositional gaps and processing gaps. Propositional gaps were evident in development of participants' concepts, links and constructs. Significant among these were conceptual distance gaps and continuity of matter gaps. Gaps such as convention gaps and relative significance gaps seem to be due to naivete in the discipline. Processing gaps included gaps in graphic decoding skills and relevant cognitive habits such as self-monitoring and consulting prior knowledge. Although the gaps were easier to detect and isolate with the above-average participants, all participants showed evidence of at least some of these gaps. Since some gaps are not unexpected at all but the highest literacy levels, not all the gaps identified are to be considered deficiencies. The gaps identified support the attention given by ANG theorists to the role of prior knowledge and metacognition as well as the value of graphic organizers in knowledge construction. In addition, this study revealed numerous gaps in graphic decoding, indicating that both direct experience and explicit instruction are needed if students are to "learn how to learn with graphics," especially those graphics central to understanding a computer simulation's representations of structures, inputs, processes and outputs. It is hypothesized that gaps similar to those revealed in this study may be at the root of some alternative conceptions documented in the literature.

  5. Exploring Genetic Attributions Underlying Radiotherapy-Induced Fatigue in Prostate Cancer Patients.

    PubMed

    Hashemi, Sepehr; Fernandez Martinez, Juan Luis; Saligan, Leorey; Sonis, Stephen

    2017-09-01

    Despite numerous proposed mechanisms, no definitive pathophysiology underlying radiotherapy-induced fatigue (RIF) has been established. However, the dysregulation of a set of 35 genes was recently validated to predict development of fatigue in prostate cancer patients receiving radiotherapy. To hypothesize novel pathways, and provide genetic targets for currently proposed pathways implicated in RIF development through analysis of the previously validated gene set. The gene set was analyzed for all phenotypic attributions implicated in the phenotype of fatigue. Initially, a "directed" approach was used by querying specific fatigue-related sub-phenotypes against all known phenotypic attributions of the gene set. Then, an "undirected" approach, reviewing the entirety of the literature referencing the 35 genes, was used to increase analysis sensitivity. The dysregulated genes attribute to neural, immunological, mitochondrial, muscular, and metabolic pathways. In addition, certain genes suggest phenotypes not previously emphasized in the context of RIF, such as ionizing radiation sensitivity, DNA damage, and altered DNA repair frequency. Several genes also associated with prostate cancer depression, possibly emphasizing variable radiosensitivity by RIF-prone patients, which may have palliative care implications. Despite the relevant findings, many of the 35 RIF-predictive genes are poorly characterized, warranting their investigation. The implications of herein presented RIF pathways are purely theoretical until specific end-point driven experiments are conducted in more congruent contexts. Nevertheless, the presented attributions are informative, directing future investigation to definitively elucidate RIF's pathoetiology. This study demonstrates an arguably comprehensive method of approaching known differential expression underlying a complex phenotype, to correlate feasible pathophysiology. Copyright © 2017 American Academy of Hospice and Palliative Medicine. All rights reserved.

  6. Cancer treatment in older adults: implications for psychosocial research.

    PubMed

    Given, Barbara; Given, Charles W

    2009-11-01

    The purpose of this article is to describe areas in need of psychosocial research for older adults who are currently receiving cancer treatment. Areas in which there are gaps in knowledge related to psychosocial research are outlined. Topics discussed for future research include comorbidity, physical function, cognitive status, frailty, and geriatric syndromes. In addition, the need for intervention to support patients and family caregivers is outlined. There are numerous areas of concern to older patients with cancer receiving treatment that warrant further study. Research is needed to identify ways to support patients and families at the time of cancer treatment so that they can make informed decisions and actively participate in cancer treatment.

  7. Characterizing quantum phase transition by teleportation

    NASA Astrophysics Data System (ADS)

    Wu, Meng-He; Ling, Yi; Shu, Fu-Wen; Gan, Wen-Cong

    2018-04-01

    In this paper we provide a novel way to explore the relation between quantum teleportation and quantum phase transition. We construct a quantum channel with a mixed state which is made from one dimensional quantum Ising chain with infinite length, and then consider the teleportation with the use of entangled Werner states as input qubits. The fidelity as a figure of merit to measure how well the quantum state is transferred is studied numerically. Remarkably we find the first-order derivative of the fidelity with respect to the parameter in quantum Ising chain exhibits a logarithmic divergence at the quantum critical point. The implications of this phenomenon and possible applications are also briefly discussed.

  8. Increasing seismicity in the U. S. midcontinent: Implications for earthquake hazard

    USGS Publications Warehouse

    Ellsworth, William L.; Llenos, Andrea L.; McGarr, Arthur F.; Michael, Andrew J.; Rubinstein, Justin L.; Mueller, Charles S.; Petersen, Mark D.; Calais, Eric

    2015-01-01

    Earthquake activity in parts of the central United States has increased dramatically in recent years. The space-time distribution of the increased seismicity, as well as numerous published case studies, indicates that the increase is of anthropogenic origin, principally driven by injection of wastewater coproduced with oil and gas from tight formations. Enhanced oil recovery and long-term production also contribute to seismicity at a few locations. Preliminary hazard models indicate that areas experiencing the highest rate of earthquakes in 2014 have a short-term (one-year) hazard comparable to or higher than the hazard in the source region of tectonic earthquakes in the New Madrid and Charleston seismic zones.

  9. Chaos and nonlinear dynamics of single-particle orbits in a magnetotaillike magnetic field

    NASA Technical Reports Server (NTRS)

    Chen, J.; Palmadesso, P. J.

    1986-01-01

    The properties of charged-particle motion in Hamiltonian dynamics are studied in a magnetotaillike magnetic field configuration. It is shown by numerical integration of the equation of motion that the system is generally nonintegrable and that the particle motion can be classified into three distinct types of orbits: bounded integrable orbits, unbounded stochastic orbits, and unbounded transient orbits. It is also shown that different regions of the phase space exhibit qualitatively different responses to external influences. The concept of 'differential memory' in single-particle distributions is proposed. Physical implications for the dynamical properties of the magnetotail plasmas and the possible generation of non-Maxwellian features in the distribution functions are discussed.

  10. The Relationship of Self-Efficacy and Complacency in Pilot-Automation Interaction

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III

    2002-01-01

    Pilot 'complacency' has been implicated as a contributing factor in numerous aviation accidents and incidents. The term has become more prominent with the increase in automation technology in modern cockpits and, therefore, research has been focused on understanding the factors that may mitigate its effect on pilot-automation interaction. The study examined self-efficacy of supervisory monitoring and the relationship between complacency on strategy of pilot use of automation for workload management under automation schedules that produce the potential for complacency. The results showed that self-efficacy can be a 'double-edged' sword in reducing potential for automation-induced complacency but limiting workload management strategies and increasing other hazardous states of awareness.

  11. Homeless Children and Their Families' Perspectives of Agency Services.

    PubMed

    Lorelle, Sonya; Grothaus, Tim

    2015-10-01

    While numerous programs aim to mediate the risks for children experiencing homelessness, there is a lack of research representing the children's and parents' perspectives in supportive housing programs. With this phenomenological qualitative study, the authors share the voices of 22 participants, including children and their families, regarding their experiences while receiving services from a homeless agency. Participating parents perceived that the program provided resources to the children that they could not provide themselves, opportunities for exposure to positive new experiences, and improved psychosocial outcomes for their children. Participants also discussed desired program changes and the responsiveness of agency staff regarding unmet needs of the children. Implications for policies and programs are discussed.

  12. Antibody-based vaccine strategies against intracellular pathogens.

    PubMed

    Casadevall, Arturo

    2018-04-25

    Historically, antibody-mediated immunity was considered effective against toxins, extracellular pathogens and viruses, while control of intracellular pathogens was the domain of cellular immunity. However, numerous observations in recent decades have conclusively shown that antibody can protect against intracellular pathogens. This paradigmatic shift has tremendous implications for immunology and vaccine design. For immunology the observation that antibody can protect against intracellular pathogens has led to the discovery of new mechanisms of antibody action. For vaccine design the knowledge that humoral immunity can be effective in protection means that the knowledge acquired in more than a century of antibody studies can be applied to make new vaccines against this class of pathogens. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Unhealthy interactions: the role of stereotype threat in health disparities.

    PubMed

    Aronson, Joshua; Burgess, Diana; Phelan, Sean M; Juarez, Lindsay

    2013-01-01

    Stereotype threat is the unpleasant psychological experience of confronting negative stereotypes about race, ethnicity, gender, sexual orientation, or social status. Hundreds of published studies show how the experience of stereotype threat can impair intellectual functioning and interfere with test and school performance. Numerous published interventions derived from this research have improved the performance and motivation of individuals targeted by low-ability stereotypes. Stereotype threat theory and research provide a useful lens for understanding and reducing the negative health consequences of interracial interactions for African Americans and members of similarly stigmatized minority groups. Here we summarize the educational outcomes of stereotype threat and examine the implications of stereotype threat for health and health-related behaviors.

  14. Unhealthy Interactions: The Role of Stereotype Threat in Health Disparities

    PubMed Central

    Burgess, Diana; Phelan, Sean M.; Juarez, Lindsay

    2013-01-01

    Stereotype threat is the unpleasant psychological experience of confronting negative stereotypes about race, ethnicity, gender, sexual orientation, or social status. Hundreds of published studies show how the experience of stereotype threat can impair intellectual functioning and interfere with test and school performance. Numerous published interventions derived from this research have improved the performance and motivation of individuals targeted by low-ability stereotypes. Stereotype threat theory and research provide a useful lens for understanding and reducing the negative health consequences of interracial interactions for African Americans and members of similarly stigmatized minority groups. Here we summarize the educational outcomes of stereotype threat and examine the implications of stereotype threat for health and health-related behaviors. PMID:23153125

  15. A Study of Two-Equation Turbulence Models on the Elliptic Streamline Flow

    NASA Technical Reports Server (NTRS)

    Blaisdell, Gregory A.; Qin, Jim H.; Shariff, Karim; Rai, Man Mohan (Technical Monitor)

    1995-01-01

    Several two-equation turbulence models are compared to data from direct numerical simulations (DNS) of the homogeneous elliptic streamline flow, which combines rotation and strain. The models considered include standard two-equation models and models with corrections for rotational effects. Most of the rotational corrections modify the dissipation rate equation to account for the reduced dissipation rate in rotating turbulent flows, however, the DNS data shows that the production term in the turbulent kinetic energy equation is not modeled correctly by these models. Nonlinear relations for the Reynolds stresses are considered as a means of modifying the production term. Implications for the modeling of turbulent vortices will be discussed.

  16. Gaps, Pseudogaps, and the Nature of Charge in Holographic Fermion Models

    NASA Astrophysics Data System (ADS)

    Vanacore, Garrett; Phillips, Philip

    Building on prior holographic constructions of Fermi arcs and Mott physics, we investigate the landscape of gapped and gapless strongly-correlated phases resulting from bulk fermion interactions in gauge/gravity duality. We test a proposed connection between bulk chiral symmetry and gapless boundary states, and discuss implications for discrete symmetry breaking in pseudogapped systems like the cuprate superconductors. Numerical methods are used to treat gravitational backreaction of bulk fermions, allowing more rigorous investigation of the existence of holographic Fermi surfaces and their adherence to Luttinger's rule. We use these techniques to study deviations from Luttinger's rule in holography, testing a recent claim that momentum-deconfined charges are at the heart of the Mott state.

  17. Discussion of "Fluvial system response to late Pleistocene-Holocene sea-level change on Santa Rosa Island, Channel Islands National Park, California" (Schumann et al., 2016. Geomorphology, 268: 322-340)

    NASA Astrophysics Data System (ADS)

    Pinter, Nicholas; Hardiman, Mark; Scott, Andrew C.; Anderson, R. Scott

    2018-01-01

    Schumann et al. (2016) presented a field assessment of late Pleistocene to Holocene fluvial sediments preserved in the valleys of Santa Rosa Island, California. This is a rigorous study, based on stratigraphic descriptions of 54 sections and numerous radiocarbon ages. The paper makes important contributions that we would like to highlight, but other parts of the paper rely upon overly simplistic interpretations that lead to misleading conclusions. In one case, a conclusion of the Schumann et al. paper has important management implications for Santa Rosa Island and similar locations, compelling us to discuss and qualify this conclusion.

  18. Large scale isolation and purification of soluble RAGE from lung tissue.

    PubMed

    Englert, Judson M; Ramsgaard, Lasse; Valnickova, Zuzana; Enghild, Jan J; Oury, Tim D

    2008-09-01

    The receptor for advanced glycation end-products (RAGE) has been implicated in numerous disease processes including: atherosclerosis, diabetic nephropathy, impaired wound healing and neuropathy to name a few. Treatment of animals with a soluble isoform of the receptor (sRAGE) has been shown to prevent and even reverse many disease processes. Isolating large quantities of pure sRAGE for in vitro and in vivo studies has hindered its development as a therapeutic strategy in other RAGE mediated diseases that require long-term therapy. This article provides an improvement in both yield and detail of a previously published method to obtain 10mg of pure, endotoxin free sRAGE from 65 g of lung tissue.

  19. A case study of sea breeze blocking regulated by sea surface temperature along the English south coast

    NASA Astrophysics Data System (ADS)

    Sweeney, J. K.; Chagnon, J. M.; Gray, S. L.

    2013-09-01

    The sensitivity of sea breeze structure to sea surface temperature (SST) and coastal orography is investigated in convection-permitting Met Office Unified Model simulations of a case study along the south coast of England. Changes in SST of 1 K are shown to significantly modify the structure of the sea breeze. On the day of the case study the sea breeze was partially blocked by coastal orography, particularly within Lyme Bay. The extent to which the flow is blocked depends strongly on the static stability of the marine boundary layer. In experiments with colder SST, the marine boundary layer is more stable, and the degree of blocking is more pronounced. The implications of prescribing fixed SST from climatology in numerical weather prediction model forecasts of the sea breeze are discussed.

  20. Fluorescent probes for real-time measurement of nitric oxide in living cells.

    PubMed

    Li, Huili; Wan, Ajun

    2015-11-07

    Nitric oxide (NO) is an important signaling molecule in biology. Both NO excess and insufficiency have been implicated in numerous physiological and pathological conditions. In order to study the diverse biological roles of NO in cells and tissues, many techniques have been developed for assaying NO. Recently, new generations of fluorescent probes have become indispensible tools for the study of NO biology because of their sensitivity, selectivity, spatiotemporal resolution, and experimental feasibility. Rational application of these probes in the study requires the understanding of the molecular mechanism that the probes are involved in. In this review, we will present an arsenal of fluorescent probes used to detect NO in living cells and animal tissues. We will also discuss the molecular mechanisms, actualities and prospects of fluorescent probes in detecting NO in cell biology.

  1. Maternal Childhood Sexual Trauma, Child Directed Aggression, Parenting Behavior, and the Moderating Role of Child Sex

    PubMed Central

    Zvara, B.J.; Mills-Koonce, R.; Cox, M.

    2016-01-01

    Using propensity-matched controls, the present study examines the associations between maternal report of child-directed aggression and observed parenting behavior across early childhood for women with and without childhood sexual trauma histories. The moderating role of child sex was also examined. The sample (n=204) is from a longitudinal study of rural poverty exploring the ways in which child, family, and contextual factors shape development over time. After controlling for numerous factors including child and primary caregiver covariates, findings reveal that childhood sexual trauma is related to sensitive parenting behavior and child-directed aggression. Findings further revealed that child sex moderates the relation between sexual trauma history and maternal behavior towards children. Implications for interventions for mothers with childhood sexual trauma histories and directions for future study are proposed. PMID:28450762

  2. Hemodynamics of the Aortic Jet and Implications for Detection of Aortic Stenosis Murmurs

    NASA Astrophysics Data System (ADS)

    Zhu, Chi; Seo, Junghee; Bakhshaee, Hani; Mittal, Rajat

    2016-11-01

    Cardiac auscultation with a stethoscope has served as the primary method for qualitative screening of cardiovascular conditions for over a hundred years. However, a lack of quantitative understanding of the flow mechanism(s) responsible for the generation of the murmurs, as well as the effect of intervening tissue on the propagation of these murmurs has been a significant limiting factor in the advancement of automated cardiac auscultation. In this study, a multiphysics computational modeling approach is used to investigate these issues. Direct numerical simulation (DNS) is used to explore the fluid dynamics of the jets formed at the aortic valve and the pressure fluctuations generated by the interaction of this jet with the aortic wall. Subsequently, structural wave propagation in the tissue is resolved by a high-order, linear viscoelastic wave solver in order to explore the propagation of the murmurs through a tissue-like material. The implications of these results for cardiac auscultation are discussed. The authors would like to acknowledge the financial support from NSF Grants IIS-1344772, CBET-1511200, and computational resource by XSEDE NSF Grant TG-CTS100002.

  3. A Review of the Efficacy, Safety, and Clinical Implications of Naturally Derived Dietary Supplements for Dyslipidemia.

    PubMed

    Thaipitakwong, Thanchanit; Aramwit, Pornanong

    2017-02-01

    Dyslipidemia is recognized as a major cause of cardiovascular disease. A number of evidence-based guidelines recommend conventional synthetic drugs as standard therapy for dyslipidemia in clinical practice. However, antihyperlipidemic drugs have some serious side effects. Naturally derived dietary supplements are becoming attractive as an alternative strategy because of their high efficacy and safety, as supported by numerous data. Moreover, they could be considered an initial treatment for dyslipidemia. The aims of this literature review were to demonstrate the efficacy, safety, and clinical implications of dietary supplements for treating dyslipidemia. We reviewed the literature, including data from in vitro, in vivo, and human studies, and clinical guideline recommendations. We classified dietary supplements by their proposed mechanisms of action on lipid metabolism and also collected daily dosage recommendations, interactions with concurrent drugs and/or foods, dosage forms, and examples of commercially available products. Various types of naturally derived dietary supplements exhibit lipid-improving properties. Efficacy and safety are acceptable; however, their use in clinical practice will require further well-designed investigations and the support of scientific data.

  4. GlobAl Distribution of GEnetic Traits (GADGET) web server: polygenic trait scores worldwide.

    PubMed

    Chande, Aroon T; Wang, Lu; Rishishwar, Lavanya; Conley, Andrew B; Norris, Emily T; Valderrama-Aguirre, Augusto; Jordan, I King

    2018-05-18

    Human populations from around the world show striking phenotypic variation across a wide variety of traits. Genome-wide association studies (GWAS) are used to uncover genetic variants that influence the expression of heritable human traits; accordingly, population-specific distributions of GWAS-implicated variants may shed light on the genetic basis of human phenotypic diversity. With this in mind, we developed the GlobAl Distribution of GEnetic Traits web server (GADGET http://gadget.biosci.gatech.edu). The GADGET web server provides users with a dynamic visual platform for exploring the relationship between worldwide genetic diversity and the genetic architecture underlying numerous human phenotypes. GADGET integrates trait-implicated single nucleotide polymorphisms (SNPs) from GWAS, with population genetic data from the 1000 Genomes Project, to calculate genome-wide polygenic trait scores (PTS) for 818 phenotypes in 2504 individual genomes. Population-specific distributions of PTS are shown for 26 human populations across 5 continental population groups, with traits ordered based on the extent of variation observed among populations. Users of GADGET can also upload custom trait SNP sets to visualize global PTS distributions for their own traits of interest.

  5. Herpesviruses dUTPases: A New Family of Pathogen-Associated Molecular Pattern (PAMP) Proteins with Implications for Human Disease

    PubMed Central

    Williams, Marshall V.; Cox, Brandon; Ariza, Maria Eugenia

    2016-01-01

    The human herpesviruses are ubiquitous viruses and have a prevalence of over 90% in the adult population. Following a primary infection they establish latency and can be reactivated over a person’s lifetime. While it is well accepted that human herpesviruses are implicated in numerous diseases ranging from dermatological and autoimmune disease to cancer, the role of lytic proteins in the pathophysiology of herpesvirus-associated diseases remains largely understudies. Only recently have we begun to appreciate the importance of lytic proteins produced during reactivation of the virus, in particular the deoxyuridine triphosphate nucleotidohydrolases (dUTPase), as key modulators of the host innate and adaptive immune responses. In this review, we provide evidence from animal and human studies of the Epstein–Barr virus as a prototype, supporting the notion that herpesviruses dUTPases are a family of proteins with unique immunoregulatory functions that can alter the inflammatory microenvironment and thus exacerbate the immune pathology of herpesvirus-related diseases including myalgic encephalomyelitis/chronic fatigue syndrome, autoimmune diseases, and cancer. PMID:28036046

  6. Script, code, information: how to differentiate analogies in the "prehistory" of molecular biology.

    PubMed

    Kogge, Werner

    2012-01-01

    The remarkable fact that twentieth-century molecular biology developed its conceptual system on the basis of sign-like terms has been the object of numerous studies and debates. Throughout these, the assumption is made that this vocabulary's emergence should be seen in the historical context of mathematical communication theory and cybernetics. This paper, in contrast, sets out the need for a more differentiated view: whereas the success of the terms "code" and "information" would probably be unthinkable outside that historical context, general semiotic and especially scriptural concepts arose far earlier in the "prehistory" of molecular biology, and in close association with biological research and phenomena. This distinction, established through a reconstruction of conceptual developments between 1870 and 1950, makes it possible to separate off a critique of the reductive implications of particular information-based concepts from the use of semiotic and scriptural concepts, which is fundamental to molecular biology. Gene-centrism and determinism are not implications of semiotic and scriptural analogies, but arose only when the vocabulary of information was superimposed upon them.

  7. Running With the Pack: Teen Peer-Relationship Qualities as Predictors of Adult Physical Health.

    PubMed

    Allen, Joseph P; Uchino, Bert N; Hafen, Christopher A

    2015-10-01

    This study assessed qualities of adolescent peer relationships as long-term predictors of physical health quality in adulthood. In an intensive multimethod, multireporter study of a community sample of 171 individuals assessed repeatedly from the ages of 13 to 27 years, physical health quality in adulthood was robustly predicted by independent reports of early-adolescent close-friendship quality and by a pattern of acquiescence to social norms in adolescent peer relationships. Predictions remained after accounting for numerous potential confounds, including prior health problems, concurrent body mass index, anxious and depressive symptoms, personality characteristics, adolescent-era financial adversity, and adolescent-era physical attractiveness. These findings have important implications for understanding the unique intensity of peer relationships in adolescence. © The Author(s) 2015.

  8. Electrophysiological Endophenotypes for Schizophrenia

    PubMed Central

    Owens, Emily; Bachman, Peter; Glahn, David C; Bearden, Carrie E

    2016-01-01

    Endophenotypes are quantitative, heritable traits that may help to elucidate the pathophysiologic mechanisms underlying complex disease syndromes, such as schizophrenia. They can be assessed at numerous levels of analysis; here, we review electrophysiological endophenotypes that have shown promise in helping us understand schizophrenia from a more mechanistic point of view. For each endophenotype, we describe typical experimental procedures, reliability, heritability, and reported gene and neurobiological associations. We discuss recent findings regarding the genetic architecture of specific electrophysiological endophenotypes, as well as converging evidence from EEG studies implicating disrupted balance of glutamatergic signaling and GABA-ergic inhibition in the pathophysiology of schizophrenia. We conclude that refining the measurement of electrophysiological endophenotypes, expanding genetic association studies, and integrating datasets are important next steps for understanding the mechanisms that connect identified genetic risk loci for schizophrenia to the disease phenotype. PMID:26954597

  9. Effects of aperture variability and wettability on immiscible displacement in fractures

    NASA Astrophysics Data System (ADS)

    Yang, Zhibing; Méheust, Yves; Neuweiler, Insa

    2017-04-01

    Fluid-fluid displacement in porous and fractured media is an important process. Understanding and controlling this process is key to many practical applications, such as hydrocarbon recovery, geological storage of CO2, groundwater remediation, etc. Here, we numerically study fluid-fluid displacement in rough-walled fractures. We focus on the combined effect of wettability and fracture surface topography on displacement patterns and interface growth. We develop a novel numerical model to simulate dynamic fluid invasion under the influence of capillary and viscous forces. The capillary force is calculated using the two principal curvatures (aperture-induced curvature and in-plane curvature) at the fluid-fluid interface, and the viscous force is taken into account by solving the fluid pressure distribution. The aperture field of a fracture is represented by a spatially correlated random field, which is described by a power spectrum for the fracture wall topography and a cutoff wave-length. We numerically produce displacement patterns ranging from stable displacement, capillary fingering, and viscous fingering, as well as the transitions between them. We show that both reducing the aperture variability and increasing the contact angle (from drainage to weak imbibition) stabilize the displacement due to the influence of the in-plane curvature, an effect analogous to that of the cooperative pore filling in porous media. Implications of these results will be discussed.

  10. Bubble Dynamics on a Heated Surface

    NASA Technical Reports Server (NTRS)

    Kassemi, M.; Rashidnia, N.

    1999-01-01

    In this work, we study steady and oscillatory thermocapillary and natural convective flows generated by a bubble on a heated solid surface. The interaction between gas and vapor bubbles with the surrounding fluid is of interest for both space and ground-based processing. A combined numerical-experimental approach is adopted here. The temperature field is visualized using Mach-Zehnder and/or Wollaston Prism Interferometry and the flow field is observed by a laser sheet flow visualization technique. A finite element numerical model is developed which solves the transient two-dimensional continuity, momentum, and energy equations and includes the effects of temperature-dependent surface tension and bubble surface deformation. Below the critical Marangoni number, the steady state low-g and 1-g temperature and velocity fields predicted by the finite element model are in excellent agreement with both the visualization experiments in our laboratory and recently published experimental results in the literature. Above the critical Marangoni number, the model predicts an oscillatory flow which is also closely confirmed by experiments. It is shown that the dynamics of the oscillatory flow are directly controlled by the thermal and hydrodynamic interactions brought about by combined natural and thermocapillary convection. Therefore, as numerical simulations show, there are considerable differences between the 1-g and low-g temperature and flow fields at both low and high Marangoni numbers. This has serious implications for both materials processing and fluid management in space.

  11. Is prayer CAM?

    PubMed

    Tippens, Kim; Marsman, Kevin; Zwickey, Heather

    2009-04-01

    Alternative medicine researchers and policy makers have classified prayer as a mind-body intervention, and thus, a modality of complementary and alternative medicine (CAM). As such, numerous epidemiological surveys of CAM utilization-which have included prayer-depict increasing CAM use, particularly in specific racial and ethnic groups. This paper discusses the implications of conflating prayer and CAM, especially regarding the definitions of both concepts and the resulting statistics of CAM utilization.

  12. Breakdown of String Perturbation Theory for Many External Particles.

    PubMed

    Ghosh, Sudip; Raju, Suvrat

    2017-03-31

    We consider massless string scattering amplitudes in a limit where the number of external particles becomes very large, while the energy of each particle remains small. Using the growth of the volume of the relevant moduli space, and by means of independent numerical evidence, we argue that string perturbation theory breaks down in this limit. We discuss some remarkable implications for the information paradox.

  13. Professional Movements, Local Appropriations, and the Limits of Educational Critique: The Cultural Production of Mixed Messages at an Urban Middle School

    ERIC Educational Resources Information Center

    Niesz, Tricia

    2008-01-01

    Although critical ethnographers have explored in some depth the ways that social critique informs how youth assess their schooling experiences, the implications of social critique by educators themselves have been of much less interest. Yet, numerous professional educational movements have been wrought from social critique or, at the very least,…

  14. The changing structure of the hardwood lumber industry with implications on technology adaptation

    Treesearch

    William Luppold; John Baumgras; John Baumgras

    2000-01-01

    The hardwood sawmilling industry has been changing over the last 50 years as a result of changes in hardwood sawtimber inventory and in the demand for hardwood lumber. In 1950 the industry was composed of numerous individual mills, few of which produced more than 3 million board feet of lumber annually. During this time the furniture industry was the major user of...

  15. Experimental verification of the spectral shift between near- and far-field peak intensities of plasmonic infrared nanoantennas.

    PubMed

    Alonso-González, P; Albella, P; Neubrech, F; Huck, C; Chen, J; Golmar, F; Casanova, F; Hueso, L E; Pucci, A; Aizpurua, J; Hillenbrand, R

    2013-05-17

    Theory predicts a distinct spectral shift between the near- and far-field optical response of plasmonic antennas. Here we combine near-field optical microscopy and far-field spectroscopy of individual infrared-resonant nanoantennas to verify experimentally this spectral shift. Numerical calculations corroborate our experimental results. We furthermore discuss the implications of this effect in surface-enhanced infrared spectroscopy.

  16. The Continuity/Discontinuity Models of Eating Disorders: A Review of the Literature and Implications for Assessment, Treatment, and Prevention

    ERIC Educational Resources Information Center

    Gleaves, David H.; Brown, Joshua D.; Warren, Cortney S.

    2004-01-01

    Are the eating disorders discrete diagnostic entities or do they fall along one or more continua ranging from normal body weight, eating behavior, and weight concerns to severely disturbed patterns? Researchers have debated this question for at least 30 years and have used numerous creative strategies to examine this and related questions. This…

  17. Latex allergy in women's health care.

    PubMed

    Fletcher, Joanne

    2013-01-01

    Latex allergy in midwifery and women's health care is not a new concept, with numerous case reports documenting adverse reactions in pregnant women to natural rubber latex in the birthing room. The practising midwife, nurse and sonographer need to be aware of the signs and symptoms of latex allergy and the implications of a severe reaction to latex not only to the woman but also the unborn child.

  18. Vaccination of elk (Cervus canadensis) with Brucella abortus strain RB51 overexpressing superoxide dismutase and glycosyltransferase genes does not induce adequate protection against experimental brucella abortus challenge

    USDA-ARS?s Scientific Manuscript database

    In recent years, elk (Cervus canadensis) have been implicated as the source of Brucella abortus infection for numerous cattle herds in the Greater Yellowstone Area (GYA). In the face of environmental and ecological changes on the landscape, the range of infected elk is expanding. Consequently, the d...

  19. The Law of Higher Education: A Comprehensive Guide to Legal Implications of Administrative Decision Making. Third Edition. Jossey-Bass Higher and Adult Education Series.

    ERIC Educational Resources Information Center

    Kaplin, William A.; Lee, Barbara A.

    This volume is the third edition of a comprehensive treatment of higher education law and is current through approximately August 1994. The nine chapters are divided into numerous sections and subsections. Chapter 1 provides a framework for understanding and integrating what is presented in subsequent chapters and a perspective for future…

  20. Internalization of G-protein-coupled receptors: Implication in receptor function, physiology and diseases.

    PubMed

    Calebiro, Davide; Godbole, Amod

    2018-04-01

    G protein-coupled receptors (GPCRs) are the largest family of membrane receptors and mediate the effects of numerous hormones and neurotransmitters. The nearly 1000 GPCRs encoded by the human genome regulate virtually all physiological functions and are implicated in the pathogenesis of prevalent human diseases such as thyroid disorders, hypertension or Parkinson's disease. As a result, 30-50% of all currently prescribed drugs are targeting these receptors. Once activated, GPCRs induce signals at the cell surface. This is often followed by internalization, a process that results in the transfer of receptors from the plasma membrane to membranes of the endosomal compartment. Internalization was initially thought to be mainly implicated in signal desensitization, a mechanism of adaptation to prolonged receptor stimulation. However, several unexpected functions have subsequently emerged. Most notably, accumulating evidence indicates that internalization can induce prolonged receptor signaling on intracellular membranes, which is apparently required for at least some biological effects of hormones like TSH, LH and adrenaline. These findings reveal an even stronger connection between receptor internalization and signaling than previously thought. Whereas new studies are just beginning to reveal an important physiological role for GPCR signaling after internalization and ways to exploit it for therapeutic purposes, future investigations will be required to explore its involvement in human disease. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Investigation of Homogeneous Relaxation Model Parameters and their Implications for Gasoline Injectors

    DOE PAGES

    Saha, Kaushik; Som, Sibendu; Battistoni, Michele

    2017-01-01

    Flash boiling is known to be a common phenomenon for gasoline direct injection (GDI) engine sprays. The Homogeneous Relaxation Model has been adopted in many recent numerical studies for predicting cavitation and flash boiling. The Homogeneous Relaxation Model is assessed in this study. Sensitivity analysis of the model parameters has been documented to infer the driving factors for the flash-boiling predictions. The model parameters have been varied over a range and the differences in predictions of the extent of flashing have been studied. Apart from flashing in the near nozzle regions, mild cavitation is also predicted inside the gasoline injectors.more » The variation in the predicted time scales through the model parameters for predicting these two different thermodynamic phenomena (cavitation, flash) have been elaborated in this study. Turbulence model effects have also been investigated by comparing predictions from the standard and Re-Normalization Group (RNG) k-ε turbulence models.« less

  2. Nitrogen and Oxygen Isotopic Studies of the Marine Nitrogen Cycle

    NASA Astrophysics Data System (ADS)

    Casciotti, Karen L.

    2016-01-01

    The marine nitrogen cycle is a complex web of microbially mediated reactions that control the inventory, distribution, and speciation of nitrogen in the marine environment. Because nitrogen is a major nutrient that is required by all life, its availability can control biological productivity and ecosystem structure in both surface and deep-ocean communities. Stable isotopes of nitrogen and oxygen in nitrate and nitrite have provided new insights into the rates and distributions of marine nitrogen cycle processes, especially when analyzed in combination with numerical simulations of ocean circulation and biogeochemistry. This review highlights the insights gained from dual-isotope studies applied at regional to global scales and their incorporation into oceanic biogeochemical models. These studies represent significant new advances in the use of isotopic measurements to understand the modern nitrogen cycle, with implications for the study of past ocean productivity, oxygenation, and nutrient status.

  3. Modeling Diet-Induced Obesity with Obesity-Prone Rats: Implications for Studies in Females

    PubMed Central

    Giles, Erin D.; Jackman, Matthew R.; MacLean, Paul S.

    2016-01-01

    Obesity is a worldwide epidemic, and the comorbidities associated with obesity are numerous. Over the last two decades, we and others have employed an outbred rat model to study the development and persistence of obesity, as well as the metabolic complications that accompany excess weight. In this review, we summarize the strengths and limitations of this model and how it has been applied to further our understanding of human physiology in the context of weight loss and weight regain. We also discuss how the approach has been adapted over time for studies in females and female-specific physiological conditions, such as menopause and breast cancer. As excess weight and the accompanying metabolic complications have become common place in our society, we expect that this model will continue to provide a valuable translational tool to establish physiologically relevant connections to the basic science studies of obesity and body weight regulation. PMID:27933296

  4. Water in geodynamical models of mantle convection and plate tectonics

    NASA Astrophysics Data System (ADS)

    Rodríguez-González, J.; Van Hunen, J.; Chotalia, K.; Lithgow-Bertelloni, C. R.; Rozel, A.; Tackley, P. J.; Nakagawa, T.

    2017-12-01

    The presence of water in the the mantle has a significant effect in the dynamical and thermal evolution of Earth, which partially explains the differences with other planets and is a key factor for the presence of life on Earth. First, a small amount of water can decrease the mantle viscosity by a several orders of magnitude, thereby changing the convection regime and affecting the thermal evolution. Second, the presence of water significantly changes the solidus curve, with crucial implications for melting. Third, water in the mantle can change the Clapeyron slope of mantle materials, which changes the depth at which phase transitions take place. The thermal and dynamical evolution of Earth under the presence of water in the mantle has been the focus of recent studies, but many questions remain unanswered. In this project we intend to investigate how the maximum water capacity of different mantle regions affects water transport and Earth's convective regime. We will study the effect phase transitions under the presence of water, which can change the buoyancy of slabs in the transition zone. We present preliminary results numerical models of global mantle convection for the whole history of earth using the numerical geodynamics software tool StagYY. We will use a new parametrisation of dehydration processes, obtained from high-resolution numerical simulations, to implement a more accurate description of the water released from the slab as it travels through the mantle. We have integrated recent experimental results of the water capacity of deep mantle minerals to study the water circulation and the total water budget. We use data from the most recent experiments and ab-inito calculations to implement a realistic rheology.

  5. A Numerical Assessment of Cosmic-Ray Energy Diffusion through Turbulent Media

    NASA Astrophysics Data System (ADS)

    Fatuzzo, M.; Melia, F.

    2014-04-01

    How and where cosmic rays are produced, and how they diffuse through various turbulent media, represent fundamental problems in astrophysics with far-reaching implications, both in terms of our theoretical understanding of high-energy processes in the Milky Way and beyond, and the successful interpretation of space-based and ground based GeV and TeV observations. For example, recent and ongoing detections, e.g., by Fermi (in space) and HESS (in Namibia), of γ-rays produced in regions of dense molecular gas hold important clues for both processes. In this paper, we carry out a comprehensive numerical investigation of relativistic particle acceleration and transport through turbulent magnetized environments in order to derive broadly useful scaling laws for the energy diffusion coefficients.

  6. Numerical simulation of the formation of a spiral galaxy

    NASA Astrophysics Data System (ADS)

    Williams, P. R.; Nelson, A. H.

    2001-08-01

    A simulation is described in which the numerical galaxy formed compares favourably in every measurable respect with contemporary bright spiral galaxies, including the formation of a distinct stellar bulge and large scale spiral arm shocks in the gas component. This is achieved in spite of the fact that only idealized proto-galactic initial conditions were used, and only simple phenomenological prescriptions for the physics of the interstellar medium (ISM) and star formation were implemented. In light of the emphasis in recent literature on the importance of the link between galaxy formation and models of the universe on cosmological scales, on the details of the physics of the ISM and star formation, and on apparent problems therein, the implications of this result are discussed.

  7. Encasement and subsidence of salt minibasins: observations from the SE Precaspian Basin and numerical modeling.

    NASA Astrophysics Data System (ADS)

    Fernandez, Naiara; Duffy, Oliver B.; Hudec, Michael R.; Jackson, Christopher A.-L.; Dooley, Tim P.; Jackson, Martin P. A.; Burg, George

    2017-04-01

    The SE Precaspian Basin is characterized by an assemblage of Upper Permian to Triassic minibasins. A recently acquired borehole-constrained 3D reflection dataset reveals the existence of abundant intrasalt reflection packages lying in between the Permo-Triassic minibasins. We propose that most of the mapped intrasalt reflection packages in the study area are minibasins originally deposited on top of salt that were later incorporated into salt by encasement processes. This makes the SE Precaspian Basin a new example of a salt province populated by encased minibasins, which until now had been mainly described from the Gulf of Mexico. Identifying salt-encased sediment packages in the study area has been crucial, not only because they provide a new exploration target, but also because they can play a key role on improving seismic imaging of adjacent or deeper stratigraphic sections. Another remarkable feature observed in the seismic dataset is the widespread occurrence of distinct seismic sequences in the Permo-Triassic minibasins. Bowl- and wedge-shaped seismic sequences define discrete periods of vertical and asymmetric minibasin subsidence. In the absence of shortening, the bowl-to-wedge transition is typically associated with the timing of basal welding and subsequent rotation of the minibasins. Timing of minibasin welding has important implications when addressing the likelihood of suprasalt reservoir charging. We performed a set of 2D numerical simulations aimed at investigating what drives the tilting of minibasins and how it relates to welding. A key observation from the numerical models is that the bowl-to-wedge transition can predate the time of basal welding.

  8. Visual representation of statistical information improves diagnostic inferences in doctors and their patients.

    PubMed

    Garcia-Retamero, Rocio; Hoffrage, Ulrich

    2013-04-01

    Doctors and patients have difficulty inferring the predictive value of a medical test from information about the prevalence of a disease and the sensitivity and false-positive rate of the test. Previous research has established that communicating such information in a format the human mind is adapted to-namely natural frequencies-as compared to probabilities, boosts accuracy of diagnostic inferences. In a study, we investigated to what extent these inferences can be improved-beyond the effect of natural frequencies-by providing visual aids. Participants were 81 doctors and 81 patients who made diagnostic inferences about three medical tests on the basis of information about prevalence of a disease, and the sensitivity and false-positive rate of the tests. Half of the participants received the information in natural frequencies, while the other half received the information in probabilities. Half of the participants only received numerical information, while the other half additionally received a visual aid representing the numerical information. In addition, participants completed a numeracy scale. Our study showed three important findings: (1) doctors and patients made more accurate inferences when information was communicated in natural frequencies as compared to probabilities; (2) visual aids boosted accuracy even when the information was provided in natural frequencies; and (3) doctors were more accurate in their diagnostic inferences than patients, though differences in accuracy disappeared when differences in numerical skills were controlled for. Our findings have important implications for medical practice as they suggest suitable ways to communicate quantitative medical data. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Meiosis, unreduced gametes, and parthenogenesis: implications for engineering clonal seed formation in crops.

    PubMed

    Ronceret, Arnaud; Vielle-Calzada, Jean-Philippe

    2015-06-01

    Meiosis and unreduced gametes. Sexual flowering plants produce meiotically derived cells that give rise to the male and female haploid gametophytic phase. In the ovule, usually a single precursor (the megaspore mother cell) undergoes meiosis to form four haploid megaspores; however, numerous mutants result in the formation of unreduced gametes, sometimes showing female specificity, a phenomenon reminiscent of the initiation of gametophytic apomixis. Here, we review the developmental events that occur during female meiosis and megasporogenesis at the light of current possibilities to engineer unreduced gamete formation. We also provide an overview of the current understanding of mechanisms leading to parthenogenesis and discuss some of the conceptual implications for attempting the induction of clonal seed production in cultivated plants.

  10. Obesity Stigma: Important Considerations for Public Health

    PubMed Central

    Heuer, Chelsea A.

    2010-01-01

    Stigma and discrimination toward obese persons are pervasive and pose numerous consequences for their psychological and physical health. Despite decades of science documenting weight stigma, its public health implications are widely ignored. Instead, obese persons are blamed for their weight, with common perceptions that weight stigmatization is justifiable and may motivate individuals to adopt healthier behaviors. We examine evidence to address these assumptions and discuss their public health implications. On the basis of current findings, we propose that weight stigma is not a beneficial public health tool for reducing obesity. Rather, stigmatization of obese individuals threatens health, generates health disparities, and interferes with effective obesity intervention efforts. These findings highlight weight stigma as both a social justice issue and a priority for public health. PMID:20075322

  11. Changes in tracheid and ray traits in fire scars of North American conifers and their ecophysiological implications.

    PubMed

    Arbellay, Estelle; Stoffel, Markus; Sutherland, Elaine K; Smith, Kevin T; Falk, Donald A

    2014-08-01

    Fire scars have been widely used as proxies for the reconstruction of fire history; however, little is known about the impact of fire injury on wood anatomy. This study investigates changes in tracheid and ray traits in fire scars of Douglas fir (Pseudotsuga menziesii), western larch (Larix occidentalis) and ponderosa pine (Pinus ponderosa), and discusses their ecophysiological implications for tree recovery from fire. Transverse and tangential microsections were prepared for light microscopy and image analysis. Measurements of tracheids and rays were made in the three spatial dimensions: axially (at different section heights), radially (in different rings) and tangentially (with increasing distance from the wound margin). Changes were strongest in the first year after fire injury, with a decrease in tracheid size (by 25-30 %) and an increase in tracheid density (by 21-53 %) for the three species. In addition, an increase in ray size (by 5-27 %) and an increase in ray density (by 19-36 %) were found in P. menziesii and L. occidentalis. Changes were comparable along the fire-injured stem and were often most marked close to the fire scar. The differentiation after fire injury of narrower and more numerous tracheids expresses a trade-off between hydraulic safety and hydraulic efficiency, while that of larger and more numerous rays serves compartmentalization and wound closure, mechanical strength and defence responses. Pinus ponderosa does not generally produce more ray tissue after fire injury and thus appears to be more adapted to fire. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Far-red fluorescent probes for canonical and non-canonical nucleic acid structures: current progress and future implications.

    PubMed

    Suseela, Y V; Narayanaswamy, Nagarjun; Pratihar, Sumon; Govindaraju, Thimmaiah

    2018-02-05

    The structural diversity and functional relevance of nucleic acids (NAs), mainly deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), are indispensable for almost all living organisms, with minute aberrations in their structure and function becoming causative factors in numerous human diseases. The standard structures of NAs, termed canonical structures, are supported by Watson-Crick hydrogen bonding. Under special physiological conditions, NAs adopt distinct spatial organisations, giving rise to non-canonical conformations supported by hydrogen bonding other than the Watson-Crick type; such non-canonical structures have a definite function in controlling gene expression and are considered as novel diagnostic and therapeutic targets. Development of molecular probes for these canonical and non-canonical DNA/RNA structures has been an active field of research. Among the numerous probes studied, probes with turn-on fluorescence in the far-red (600-750 nm) region are highly sought-after due to minimal autofluorescence and cellular damage. Far-red fluorescent probes are vital for real-time imaging of NAs in live cells as they provide good resolution and minimal perturbation of the cell under investigation. In this review, we present recent advances in the area of far-red fluorescent probes of DNA/RNA and non-canonical G-quadruplex structures. For the sake of continuity and completeness, we provide a brief overview of visible fluorescent probes. Utmost importance is given to design criteria, characteristic properties and biological applications, including in cellulo imaging, apart from critical discussion on limitations of the far-red fluorescent probes. Finally, we offer current and future prospects in targeting canonical and non-canonical NAs specific to cellular organelles, through sequence- and conformation-specific far-red fluorescent probes. We also cover their implications in chemical and molecular biology, with particular focus on decoding various disease mechanisms involving NAs.

  13. The barrier, airway particle clearance, placental and detoxification functions of autism susceptibility genes.

    PubMed

    Carter, C J

    2016-10-01

    Even taking problems of diagnosis into account, a five-fold increase in the incidence of autism in recent decades, in the absence of any known changes in the human gene pool suggests a strong environmental influence. Numerous pollutants have been implicated in epidemiological studies, including pesticides, heavy metals, industrial solvents, air pollutants, particulate matter, bisphenol A, phthalates and flame retardants. Many genes have been implicated in autism, some of which are directly related to detoxification processes. Many are also expressed prenatally in the frontal cortex when the effects of such toxins on neurodevelopment are most relevant. To gain access to the foetal brain, toxins must pass placental and blood/brain barriers and access to maternal or children's blood necessitates passage across skin, airway and intestinal barriers. Literature survey of a subset of 206 genes, defined as prime autism susceptibility candidates from an Autworks/Genotator analysis, revealed that most could be related to barrier function at blood/brain, skin, intestinal, placental or other interfaces. These genes were highly enriched in proteome datasets from blood/brain and placental trophoblast barriers and many localised to skin, intestinal, lung, umbilical and placental compartments. Many were also components of the exosomal/transcytosis pathway that is involved in the transfer of compounds across cells themselves, rather than between them. Several are involved in the control of respiratory cilia that sweep mucus and noxious particles from the airways. A key role of autism susceptibility genes may thus relate to their ability to modulate the access of numerous toxins to children, and adults and, during gestation, to the developing foetal brain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The effects of short-lived radionuclides and porosity on the early thermo-mechanical evolution of planetesimals

    NASA Astrophysics Data System (ADS)

    Lichtenberg, Tim; Golabek, Gregor J.; Gerya, Taras V.; Meyer, Michael R.

    2016-08-01

    The thermal history and internal structure of chondritic planetesimals, assembled before the giant impact phase of chaotic growth, potentially yield important implications for the final composition and evolution of terrestrial planets. These parameters critically depend on the internal balance of heating versus cooling, which is mostly determined by the presence of short-lived radionuclides (SLRs), such as 26Al and 60Fe, as well as the heat conductivity of the material. The heating by SLRs depends on their initial abundances, the formation time of the planetesimal and its size. It has been argued that the cooling history is determined by the porosity of the granular material, which undergoes dramatic changes via compaction processes and tends to decrease with time. In this study we assess the influence of these parameters on the thermo-mechanical evolution of young planetesimals with both 2D and 3D simulations. Using the code family I2ELVIS/I3ELVIS we have run numerous 2D and 3D numerical finite-difference fluid dynamic models with varying planetesimal radius, formation time and initial porosity. Our results indicate that powdery materials lowered the threshold for melting and convection in planetesimals, depending on the amount of SLRs present. A subset of planetesimals retained a powdery surface layer which lowered the thermal conductivity and hindered cooling. The effect of initial porosity was small, however, compared to those of planetesimal size and formation time, which dominated the thermo-mechanical evolution and were the primary factors for the onset of melting and differentiation. We comment on the implications of this work concerning the structure and evolution of these planetesimals, as well as their behavior as possible building blocks of terrestrial planets.

  15. Scaling for turbulent viscosity of buoyant plumes in stratified fluids: PIV measurement with implications for submarine hydrothermal plume turbulence

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; He, Zhiguo; Jiang, Houshuo

    2017-11-01

    Time-resolved particle image velocimetry (PIV) has been used to measure instantaneous two-dimensional velocity vector fields of laboratory-generated turbulent buoyant plumes in linearly stratified saltwater over extended periods of time. From PIV-measured time-series flow data, characteristics of plume mean flow and turbulence have been quantified. To be specific, maximum plume penetration scaling and entrainment coefficient determined from the mean flow agree well with the theory based on the entrainment hypothesis for buoyant plumes in stratified fluids. Besides the well-known persistent entrainment along the plume stem (i.e., the 'plume-stem' entrainment), the mean plume velocity field shows persistent entrainment along the outer edge of the plume cap (i.e., the 'plume-cap' entrainment), thereby confirming predictions from previous numerical simulation studies. To our knowledge, the present PIV investigation provides the first measured flow field data in the plume cap region. As to measured plume turbulence, both the turbulent kinetic energy field and the turbulence dissipation rate field attain their maximum close to the source, while the turbulent viscosity field reaches its maximum within the plume cap region; the results also show that maximum turbulent viscosity scales as νt,max = 0.030(B/N)1/2, where B is source buoyancy flux and N is ambient buoyancy frequency. These PIV data combined with previously published numerical simulation results have implications for understanding the roles of hydrothermal plume turbulence, i.e. plume turbulence within the cap region causes the 'plume-cap' entrainment that plays an equally important role as the 'plume-stem' entrainment in supplying the final volume flux at the plume spreading level.

  16. Magnetic fields threading black holes: restrictions from general relativity and implications for astrophysical black holes

    NASA Astrophysics Data System (ADS)

    Garofalo, David

    2017-07-01

    The idea that black hole spin is instrumental in the generation of powerful jets in active galactic nuclei and X-ray binaries is arguably the most contentious claim in black hole astrophysics. Because jets are thought to originate in the context of electromagnetism, and the modeling of Maxwell fields in curved spacetime around black holes is challenging, various approximations are made in numerical simulations that fall under the guise of `ideal magnetohydrodynamics'. But the simplifications of this framework may struggle to capture relevant details of real astrophysical environments near black holes. In this work, we highlight tension between analytic and numerical results, specifically between the analytically derived conserved Noether currents for rotating black hole spacetimes and the results of general relativistic numerical simulations (GRMHD). While we cannot definitively attribute the issue to any specific approximation used in the numerical schemes, there seem to be natural candidates, which we explore. GRMHD notwithstanding, if electromagnetic fields around rotating black holes are brought to the hole by accretion, we show from first principles that prograde accreting disks likely experience weaker large-scale black hole-threading fields, implying weaker jets than in retrograde configurations.

  17. A comparative analysis of numerical approaches to the mechanics of elastic sheets

    NASA Astrophysics Data System (ADS)

    Taylor, Michael; Davidovitch, Benny; Qiu, Zhanlong; Bertoldi, Katia

    2015-06-01

    Numerically simulating deformations in thin elastic sheets is a challenging problem in computational mechanics due to destabilizing compressive stresses that result in wrinkling. Determining the location, structure, and evolution of wrinkles in these problems has important implications in design and is an area of increasing interest in the fields of physics and engineering. In this work, several numerical approaches previously proposed to model equilibrium deformations in thin elastic sheets are compared. These include standard finite element-based static post-buckling approaches as well as a recently proposed method based on dynamic relaxation, which are applied to the problem of an annular sheet with opposed tractions where wrinkling is a key feature. Numerical solutions are compared to analytic predictions of the ground state, enabling a quantitative evaluation of the predictive power of the various methods. Results indicate that static finite element approaches produce local minima that are highly sensitive to initial imperfections, relying on a priori knowledge of the equilibrium wrinkling pattern to generate optimal results. In contrast, dynamic relaxation is much less sensitive to initial imperfections and can generate low-energy solutions for a wide variety of loading conditions without requiring knowledge of the equilibrium solution beforehand.

  18. The genetics of celiac disease: A comprehensive review of clinical implications.

    PubMed

    Dieli-Crimi, Romina; Cénit, M Carmen; Núñez, Concepción

    2015-11-01

    Celiac disease (CD) is a complex immune-related disease with a very strong genetic component. Multiple genetic findings over the last decade have added to the already known MHC influence numerous genetic variants associated to CD susceptibility. Currently, it is well-established that 6 MHC and 39 non-MHC loci, including a higher number of independent genetic variants, are associated to disease risk. Moreover, additional regions have been recently implicated in the disease, which would increase the number of involved loci. Together, the firmly described genetic variants account for roughly 31% of CD heritability, being 25% explained by the MHC influence. These new variants represent markers of disease risk and turn the identification of the causal genes and the causal variants inside the associated loci, as well as their precise biological role on the disease, into a major challenge in CD research. Numerous studies have been developed with this aim showing the high impact of risk variants on gene expression. These studies also indicate a central role of CD4(+) T cells in CD pathogenesis and point to B cells as important players, which is in accordance with the key steps highlighted by the immunological models of pathogenesis. We comprehensively summarize the current knowledge about the genetic architecture of CD, characterized by multiple low-risk variants located within diverse loci which are most likely affecting genes with immune-related functions. These findings are leading to a better understanding of CD pathogenesis and helping in the design of new treatments. The repertoire of potential drug targets for CD has largely broadened last years, bringing us closer to get alternative or complementary treatments to the life-long gluten-free diet, the only effective treatment so far. Epigenetics and microbiota are emerging as potent factors modulating disease risk and putatively affecting disease manifestation, which are also being explored as therapeutic targets. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. A critical review of principal traffic noise models: Strategies and implications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Garg, Naveen, E-mail: ngarg@mail.nplindia.ernet.in; Department of Mechanical, Production and Industrial Engineering, Delhi Technological University, Delhi 110042; Maji, Sagar

    2014-04-01

    The paper presents an exhaustive comparison of principal traffic noise models adopted in recent years in developed nations. The comparison is drawn on the basis of technical attributes including source modelling and sound propagation algorithms. Although the characterization of source in terms of rolling and propulsion noise in conjunction with advanced numerical methods for sound propagation has significantly reduced the uncertainty in traffic noise predictions, the approach followed is quite complex and requires specialized mathematical skills for predictions which is sometimes quite cumbersome for town planners. Also, it is sometimes difficult to follow the best approach when a variety ofmore » solutions have been proposed. This paper critically reviews all these aspects pertaining to the recent models developed and adapted in some countries and also discusses the strategies followed and implications of these models. - Highlights: • Principal traffic noise models developed are reviewed. • Sound propagation algorithms used in traffic noise models are compared. • Implications of models are discussed.« less

  20. Is Prayer CAM?

    PubMed Central

    Marsman, Kevin; Zwickey, Heather

    2009-01-01

    Abstract Background Alternative medicine researchers and policy makers have classified prayer as a mind–body intervention, and thus, a modality of complementary and alternative medicine (CAM). As such, numerous epidemiological surveys of CAM utilization—which have included prayer—depict increasing CAM use, particularly in specific racial and ethnic groups. Objectives This paper discusses the implications of conflating prayer and CAM, especially regarding the definitions of both concepts and the resulting statistics of CAM utilization. PMID:19388867

  1. The Classification and Geomorphic Implications of Thaw Lakes on the Arctic Coastal Plain, Alaska

    DTIC Science & Technology

    1975-12-01

    Plain is underlain by ice-rich marine sediments , the product of several marine transgressions and regressions. Numerous thaw lake basins of...variable morphology and distribution have developed on the perennially frozen sediments (permafrost) of this low-lying plain. Most notable are the large...mechanism of thaw lake formation was recognized whereby sediment laden ice rafts initiated thawing of the permafrost and formation of lake basins

  2. The second chance story of HIV-1 DNA: Unintegrated? Not a problem!

    PubMed

    Wu, Yuntao

    2008-07-09

    Accumulation of high levels of unintegrated viral DNA is a common feature of retroviral infection. It was recently discovered that coinfection of cells with integrated and unintegrated HIV-1 can result in complementation, allowing viral replication in the absence of integration. This new mode of HIV-1 replication has numerous implications for the function of unintegrated viral DNA and its application as a therapeutic vector.

  3. Implication of inflammatory macrophages, nuclear receptors and interferon regulatory factors in increased virulence of pandemic 2009 H1N1 influenza A virus after host adaptation

    USDA-ARS?s Scientific Manuscript database

    While pandemic 2009 H1N1 influenza A viruses were responsible for numerous severe infections in humans, these viruses do not typically cause corresponding severe disease in mammalian models. However, the generation of a virulent 2009 H1N1 virus following serial lung passage in mice has allowed for...

  4. Numerical investigation of road salt impact on an urban wellfield.

    PubMed

    Bester, M L; Frind, E O; Molson, J W; Rudolph, D L

    2006-01-01

    The impact of road salt on a wellfield in a complex glacial moraine aquifer system is studied by numerical simulation. The moraine underlies an extensive urban and industrial landscape, which draws its water supply from >20 wellfields, several of which are approaching or have exceeded the drinking water limit for chloride. The study investigates the mechanisms of road salt infiltration, storage, and transport in the subsurface and assesses the effectiveness of mitigation measures designed to reduce the impact. The three-dimensional transport model accounts for increases in salt loading, as well as growth of the urbanized area and road network over the past 50 years. The simulations, which focus on one impacted wellfield, show chloride plumes originating mainly at arterial roads and migrating through aquitard windows into the water supply aquifers. The results suggest that the aquifer system contains a large and heterogeneously distributed mass of chloride and that concentrations in the aquifer can be substantially higher than the concentrations in the well water. Future impact scenarios indicate that although the system responds rapidly to reductions in salt loading, the residual chloride mass may take decades to flush out, even if road salting were discontinued. The implications with respect to urban wellfields in typical snow-belt areas are discussed.

  5. Impact of Profiling Technologies in the Understanding of Recombinant Protein Production

    NASA Astrophysics Data System (ADS)

    Vijayendran, Chandran; Flaschel, Erwin

    Since expression profiling methods have been available in a high throughput fashion, the implication of these technologies in the field of biotechnology has increased dramatically. Microarray technology is one such unique and efficient methodology for simultaneous exploration of expression levels of numerous genes. Likewise, two-dimensional gel electrophoresis or multidimensional liquid chromatography coupled with mass spectrometry are extensively utilised for studying expression levels of numerous proteins. In the field of biotechnology these highly parallel analytical methods have paved the way to study and understand various biological phenomena depending on expression patterns. The next phenomenological level is represented by the metabolome and the (metabolic) fluxome. However, this chapter reviews gene and protein profiling and their impact on understanding recombinant protein production. We focus on the computational methods utilised for the analyses of data obtained from these profiling technologies as well as prominent results focusing on recombinant protein expression with Escherichia coli. Owing to the knowledge accumulated with respect to cellular signals triggered during recombinant protein production, this field is on the way to design strategies for developing improved processes. Both gene and protein profiling have exhibited a handful of functional categories to concentrate on in order to identify target genes and proteins, respectively, involved in the signalling network with major impact on recombinant protein production.

  6. Evidence and evidence gaps in the treatment of Eustachian tube dysfunction and otitis media

    PubMed Central

    Teschner, Magnus

    2016-01-01

    Evidence-based medicine is an approach to medical treatment intended to optimize patient-oriented decision-making on the basis of empirically proven effectiveness. For this purpose, a classification system has been established to categorize studies – and hence therapy options – in respect of associated evidence according to defined criteria. The Eustachian tube connects the nasopharynx with the middle ear cavity. Its key function is to ensure middle ear ventilation. Compromised ventilation results in inflammatory middle ear disorders. Numerous evidence-based therapy options are available for the treatment of impaired middle ear ventilation and otitis media, the main therapeutic approach being antibiotic treatment. More recent procedures such as balloon dilation of the Eustachian tube have also shown initial success but must undergo further evaluation with regard to evidence. There is, as yet, no evidence for some of the other long-established procedures. Owing to the multitude of variables, the classification of evidence levels for various treatment approaches calls for highly diversified assessment. Numerous evidence-based studies are therefore necessary in order to evaluate the evidence pertaining to existing and future therapy solutions for impaired middle ear ventilation and otitis media. If this need is addressed, a wealth of implications can be expected for therapeutic approaches in the years to come. PMID:28025605

  7. Thermodynamic sensitivities in observed and simulated extreme-rain-producing mesoscale convective systems

    NASA Astrophysics Data System (ADS)

    Schumacher, R. S.; Peters, J. M.

    2015-12-01

    Mesoscale convective systems (MCSs) are responsible for a large fraction of warm-season extreme rainfall events over the continental United States, as well as other midlatitude regions globally. The rainfall production in these MCSs is determined by numerous factors, including the large-scale forcing for ascent, the organization of the convection, cloud microphysical processes, and the surrounding thermodynamic and kinematic environment. Furthermore, heavy-rain-producing MCSs are most common at night, which means that well-studied mechanisms for MCS maintenance and organization such as cold pools (gravity currents) are not always at work. In this study, we use numerical model simulations and recent field observations to investigate the sensitivity of low-level MCS structures, and their influences on rainfall, to the details of the thermodynamic environment. In particular, small alterations to the initial conditions in idealized and semi-idealized simulations result in comparatively large precipitation changes, both in terms of the intensity and the spatial distribution. The uncertainties in the thermodynamic enviroments in the model simulations will be compared with high-resolution observations from the Plains Elevated Convection At Night (PECAN) field experiment in 2015. The results have implications for the paradigms of "surface-based" versus "elevated" convection, as well as for the predictability of warm-season convective rainfall.

  8. The psychometric properties of an Arabic numeric pain rating scale for measuring osteoarthritis knee pain.

    PubMed

    Alghadir, Ahmad H; Anwer, Shahnawaz; Iqbal, Zaheen Ahmed

    2016-12-01

    The aims of this study were to translate the numeric rating scale (NRS) into Arabic and to evaluate the test-retest reliability and convergent validity of an Arabic Numeric Pain Rating Scale (ANPRS) for measuring pain in osteoarthritis (OA) of the knee. The English version of the NRS was translated into Arabic as per the translation process guidelines for patient-rated outcome scales. One hundred twenty-one consecutive patients with OA of the knee who had experienced pain for more than 6 months were asked to report their pain levels on the ANPRS, visual analogue scale (VAS), and verbal rating scale (VRS). A second assessment was performed 48 h after the first to assess test-retest reliability. The test-retest reliability was calculated using the intraclass correlation coefficient (ICC2,1). The convergent validity was assessed using Spearman rank correlation coefficient. In addition, the minimum detectable change (MDC) and standard error of measurement (SEM) were also assessed. The repeatability of ANPRS was good to excellent (ICC 0.89). The SEM and MDC were 0.71 and 1.96, respectively. Significant correlations were found with the VAS and VRS scores (p <0.01). The Arabic numeric pain rating scale is a valid and reliable scale for measuring pain levels in OA of the knee. Implications for Rehabilitation The Arabic Numeric Pain Rating Scale (ANPRS) is a reliable and valid instrument for measuring pain in osteoarthritis (OA) of the knee, with psychometric properties in agreement with other widely used scales. The ANPRS is well correlated with the VAS and NRS scores in patients with OA of the knee. The ANPRS appears to measure pain intensity similar to the VAS, NRS, and VRS and may provide additional advantages to Arab populations, as Arabic numbers are easily understood by this population.

  9. Control of rift asymmetry and segmentation on the thermal architecture of hyperextended rift systems: insights from Pyrenean field observations and numerical modelling

    NASA Astrophysics Data System (ADS)

    Lescoutre, Rodolphe; Tugend, Julie; Brune, Sascha; Manatschal, Gianreto

    2017-04-01

    Mid-Cretaceous rift basins are exposed in the Pyrenees providing key information on rifted domain formation that is not available at present-day rift system. Substantial paleotemperature and thermochronological data have been collected and published in numerous recent papers. These data show a strong heterogeneity in the distribution of peak temperatures within the Cretaceous rift basins. Locations that experienced relatively high or low temperatures appear to cluster in specific areas along strike. These areas have been interpreted as either reflecting hot and cold conditions during rifting, or alternatively, a change in the polarity of a strongly asymmetric rift systems. In this study, we test if the observed variability of peak temperatures can be explained by segmentation and a change in polarity of an asymmetrical upper/lower plate rift model. To this aim we restore the observed syn- to early post-rift peak temperatures to their paleo-location within sections across the evolving rift system. In the meantime, we conduct numerical models of rift migration leading to asymmetrical extension that are benchmarked with geological and geophysical observations from the Pyrenees. From the models, we extract thermal information at different stages of rifting that are finally compared to the thermal data from the Pyrenean Cretaceous rift basins. This work employs a novel approach by comparing thermal output from numerical modelling with the distribution of peak temperatures and thermal gradient from field data. As such, these results may have substantial implications to further understand the pre-orogenic thermal evolution of the Pyrenean rift system and the role of segmentation. More generally, the results of this work may unravel the role of rift asymmetry and segmentation on the thermal architecture of hyperextended rift basins and margins.

  10. Defend or repair? Explaining responses to in-group moral failure by disentangling feelings of shame, rejection, and inferiority.

    PubMed

    Gausel, Nicolay; Leach, Colin Wayne; Vignoles, Vivian L; Brown, Rupert

    2012-05-01

    Research on shame about in-group moral failure has yielded paradoxical results. In some studies, shame predicts self-defensive motivations to withdraw. In other studies, shame predicts pro-social motivations, such as restitution. We think that this paradox can be explained by disentangling the numerous appraisals and feelings subsumed under the label "shame." In 2 studies, we asked community samples of Norwegians about their in-group's discrimination against the Tater minority. Confirmatory factor analysis validated the measures of the appraisals and feelings used in Study 1 (N = 206) and Study 2 (N = 173). In both studies, an appraisal of the in-group as suffering a moral defect best predicted felt shame, whereas an appraisal of concern for condemnation of the in-group best predicted felt rejection. In both studies, felt rejection best predicted self-defensive motivation, whereas felt shame best predicted pro-social motivation. Implications for conceptualizing and studying shame are discussed.

  11. Implications of Parkinson's disease pathophysiology for the development of cell replacement strategies and drug discovery in neurodegenerative diseases.

    PubMed

    Pan-Montojo, Francisco; Funk, Richard H W

    2012-11-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder traditionally characterized by the loss of dopaminergic neurons in the substantia nigra (SN) at the midbrain. The potential use of adult or embryonic stem cells, induced pluriputent stem (iPS) cells and endogenous neurogenesis in cell replacement strategies has lead to numerous studies and clinical trials in this direction. It is now possible to differentiate stem cells into dopaminergic neurons in vitro and clinical trials have shown an improvement in PD-related symptoms after intra-striatal embryonic transplants and acceptable cell survival rates on the mid term. However, clinical improvement is transitory and associated with a strong placebo effect. Interestingly, recent pathological studies in PD patients who received embryonic stem cells show that in PD patients, grafted neurons show PD-related pathology. In this manuscript we review the latest findings regarding PD pathophysiology and give an outlook on the implications of these findings in how cell replacement strategies for PD treatment should be tested. These include changes in the type of animal models used, the preparation/conditioning of the cells before intracerebral injection, specially regarding backbone chronic diseases in iPS cells and determining the optimal proliferation, survival, differentiation and migration capacity of the grafted cells.

  12. White Matter Development in Adolescence: The Influence of Puberty and Implications for Affective Disorders

    PubMed Central

    Ladouceur, Cecile D.; Peper, Jiska S.; Crone, Eveline A.; Dahl, Ronald E.

    2011-01-01

    There have been rapid advances in understanding a broad range of changes in brain structure and function during adolescence, and a growing interest in identifying which of these neurodevelopmental changes are directly linked with pubertal maturation—at least in part because of their potential to provide insights into the numerous emotional and behavioral health problems that emerge during this developmental period. This review focuses on what is known about the influence of puberty on white matter development in adolescence. We focus on white matter because of its role in providing the structural architectural organization of the brain and as a structural correlate of communication within complex neural systems. We begin with a review of studies that report sex differences or sex by age interactions in white matter development as these findings can provide, although indirectly, information relevant to puberty-related changes. Studies are also critically reviewed based on methodological procedures used to assess pubertal maturation and relations with white matter changes. Findings are discussed in light of their implications for the development of neural systems underlying the regulation of emotion and behavior and how alterations in the development of these systems may mediate risk for affective disorders in vulnerable adolescents. PMID:22247751

  13. Glacier crevasses: Observations, models, and mass balance implications

    NASA Astrophysics Data System (ADS)

    Colgan, William; Rajaram, Harihar; Abdalati, Waleed; McCutchan, Cheryl; Mottram, Ruth; Moussavi, Mahsa S.; Grigsby, Shane

    2016-03-01

    We review the findings of approximately 60 years of in situ and remote sensing studies of glacier crevasses, as well as the three broad classes of numerical models now employed to simulate crevasse fracture. The relatively new insight that mixed-mode fracture in local stress equilibrium, rather than downstream advection alone, can introduce nontrivial curvature to crevasse geometry may merit the reinterpretation of some key historical observation studies. In the past three decades, there have been tremendous advances in the spatial resolution of satellite imagery, as well as fully automated algorithms capable of tracking crevasse displacements between repeat images. Despite considerable advances in developing fully transient three-dimensional ice flow models over the past two decades, both the zero stress and linear elastic fracture mechanics crevasse models have remained fundamentally unchanged over this time. In the past decade, however, multidimensional and transient formulations of the continuum damage mechanics approach to simulating ice fracture have emerged. The combination of employing damage mechanics to represent slow upstream deterioration of ice strength and fracture mechanics to represent rapid failure at downstream termini holds promise for implementation in large-scale ice sheet models. Finally, given the broad interest in the sea level rise implications of recent and future cryospheric change, we provide a synthesis of 10 mechanisms by which crevasses can influence glacier mass balance.

  14. Influence of a large-scale field on energy dissipation in magnetohydrodynamic turbulence

    NASA Astrophysics Data System (ADS)

    Zhdankin, Vladimir; Boldyrev, Stanislav; Mason, Joanne

    2017-07-01

    In magnetohydrodynamic (MHD) turbulence, the large-scale magnetic field sets a preferred local direction for the small-scale dynamics, altering the statistics of turbulence from the isotropic case. This happens even in the absence of a total magnetic flux, since MHD turbulence forms randomly oriented large-scale domains of strong magnetic field. It is therefore customary to study small-scale magnetic plasma turbulence by assuming a strong background magnetic field relative to the turbulent fluctuations. This is done, for example, in reduced models of plasmas, such as reduced MHD, reduced-dimension kinetic models, gyrokinetics, etc., which make theoretical calculations easier and numerical computations cheaper. Recently, however, it has become clear that the turbulent energy dissipation is concentrated in the regions of strong magnetic field variations. A significant fraction of the energy dissipation may be localized in very small volumes corresponding to the boundaries between strongly magnetized domains. In these regions, the reduced models are not applicable. This has important implications for studies of particle heating and acceleration in magnetic plasma turbulence. The goal of this work is to systematically investigate the relationship between local magnetic field variations and magnetic energy dissipation, and to understand its implications for modelling energy dissipation in realistic turbulent plasmas.

  15. Enteric bacterial proteases in inflammatory bowel disease- pathophysiology and clinical implications

    PubMed Central

    Carroll, Ian M; Maharshak, Nitsan

    2013-01-01

    Numerous reports have identified a dysbiosis in the intestinal microbiota in patients suffering from inflammatory bowel diseases (IBD), yet the mechanism(s) in which this complex microbial community initiates or perpetuates inflammation remains unclear. The purpose of this review is to present evidence for one such mechanism that implicates enteric microbial derived proteases in the pathogenesis of IBD. We highlight and discuss studies demonstrating that proteases and protease receptors are abundant in the digestive system. Additionally, we investigate studies demonstrating an association between increased luminal protease activity and activation of protease receptors, ultimately resulting in increased intestinal permeability and exacerbation of colitis in animal models as well as in human IBD. Proteases are essential for the normal functioning of bacteria and in some cases can serve as virulence factors for pathogenic bacteria. Although not classified as traditional virulence factors, proteases originating from commensal enteric bacteria also have a potential association with intestinal inflammation via increased enteric permeability. Reports of increased protease activity in stools from IBD patients support a possible mechanism for a dysbiotic enteric microbiota in IBD. A better understanding of these pathways and characterization of the enteric bacteria involved, their proteases, and protease receptors may pave the way for new therapeutic approaches for these diseases. PMID:24431894

  16. Comparison of circulating and intratumoral regulatory T cells in patients with renal cell carcinoma.

    PubMed

    Asma, Gati; Amal, Gorrab; Raja, Marrakchi; Amine, Derouiche; Mohammed, Chebil; Amel, Ben Ammar Elgaaied

    2015-05-01

    The clear evidence that tumor-infiltrating lymphocytes (TIL) exists in the tumor microenvironment raises the question why renal cell carcinoma (RCC) progresses. Numerous studies support the implication of CD4(+)CD25(high) regulatory T (Treg) cells in RCC development. We aimed in this study to characterize the phenotype and function of circulating and intratumoral Treg cells of RCC patient in order to evaluate their implication in the inhibition of the local antitumor immune response. Our results demonstrate that the proportion of Treg in TIL was, in average, similar to that found in circulating CD4(+) T cells of patients or healthy donors. However, intratumoral Treg exhibit a marked different phenotype when compared with the autologous circulating Treg. A higher CD25 mean level, HLA-DR, Fas, and GITR, and a lower CD45RA expression were observed in intratumoral Treg, suggesting therefore that these cells are effector in the tumor microenvironment. Additionally, intratumoral Treg showed a higher inhibitory function on autologous CD4(+)CD25(-) T cells when compared with circulating Treg that may be explained by an overexpression of FoxP3 transcription factor. These findings suggest that intratumoral Treg could be major actors in the impairment of local antitumor immune response for RCC patients.

  17. Implications of domestic food practices for the presence of bioactive components in meats with special reference to meat-based functional foods.

    PubMed

    Jiménez-Colmenero, Francisco; Cofrades, Susana; Herrero, Ana M; Ruiz-Capillas, Claudia

    2017-06-14

    Although an essential component of the diet, the consumption of meat is in question. Meat is a major source of beneficial compounds but it also contains other substances with negative health implications. Functional foods, which are leading trends in the food industry, constitute an excellent opportunity for the meat sector to improve healthier meat options. Most studies on meat-based functional foods have focused mainly on the application of different strategies (animal production practices and meat transformation systems) to improve (increase/reduce) the presence of bioactive (healthy/unhealthy) compounds; these have led to the development of numerous products, many of them by the meat industry. However, like other foods, after purchase meats undergo certain processes before they are consumed, and these affect their composition. Although domestic handling practices can significantly alter the make-up of the marketed product in terms of healthy/unhealthy compounds, there are very few studies on their consequences. This paper provides an overview of the influence of different domestic practices (from shopping to eating) habitually followed by consumers on the presence of, and consequently on the levels of exposure to, (healthy and unhealthy) food components associated with the consumption of meats, with special reference to meat-based functional foods.

  18. Genetic studies of Age-related macular degeneration: lessons, challenges and opportunities for disease management

    PubMed Central

    Ratna Priya, Rinki; Chew, Emily Y.; Swaroop, Anand

    2012-01-01

    Age-related macular degeneration (AMD) is a common cause of visual impairment in individuals over 55 years of age worldwide. The varying clinical phenotypes of AMD result from contributions of genetic, epigenetic and non-genetic (environmental) factors. Genetic studies of AMD have come of age as a direct result of tremendous gains from human genome project, genomewide association studies and identification of numerous susceptibility loci. These findings have implicated immune response, high-density lipoprotein cholesterol metabolism, extracellular matrix, and angiogenesis signaling pathways in disease pathophysiology. Here, we address how the wealth of genetic findings in AMD is expected to impact the practice of medicine, providing opportunities for improved risk assessment, molecular diagnosis, preventive and therapeutic intervention. We propose that the potential of using genetic variants for monitoring treatment response (pharmacogenetics) may usher a new era of personalized medicine in the clinical management of AMD. PMID:23009893

  19. Trait approach motivation moderates the aftereffects of self-control

    PubMed Central

    Crowell, Adrienne; Kelley, Nicholas J.; Schmeichel, Brandon J.

    2014-01-01

    Numerous experiments have found that exercising self-control reduces success on subsequent, seemingly unrelated self-control tasks. Such evidence lends support to a strength model that posits a limited and depletable resource underlying all manner of self-control. Recent theory and evidence suggest that exercising self-control may also increase approach-motivated impulse strength. The two studies reported here tested two implications of this increased approach motivation hypothesis. First, aftereffects of self-control should be evident even in responses that require little or no self-control. Second, participants higher in trait approach motivation should be particularly susceptible to such aftereffects. In support, exercising self-control led to increased optimism (Study 1) and broadened attention (Study 2), but only among individuals higher in trait approach motivation. These findings suggest that approach motivation is an important key to understanding the aftereffects of exercising self-control. PMID:25324814

  20. Scoliosis: review of types of curves, etiological theories and conservative treatment.

    PubMed

    Shakil, Halima; Iqbal, Zaheen A; Al-Ghadir, Ahmad H

    2014-01-01

    Scoliosis is the deviation in the normal vertical spine. Although there are numerous studies available about treatment approaches for scoliosis, the numbers of studies that talk about its etiology and pathology are limited. Aim of this study was to discuss the different types of scoliosis; its curves and etiological theories; and to note their implication on its treatment. We examined various electronic databases including Pub MED, Medline, Cinhal, Cochrane library and Google scholar using key words "scoliosis", "etiology", "pathology" and "conservative treatment". References of obtained articles were also examined for cross references. The search was limited to articles in English language. A total of 145 papers, about Prevalence, History, Symptoms, classification, Biomechanics, Pathogenesis, Kinematics and Treatment of scoliosis were identified to be relevant. To choose the appropriate treatment approach for scoliosis we need to understand its etiology and pathogenesis first. Early intervention with conservative treatment like physiotherapy and bracing can prevent surgery.

  1. Growing Up Amid Ethno-political Conflict: Aggression and Emotional Desensitization Promote Hostility to Ethnic Out-groups

    PubMed Central

    Niwa, Erika Y.; Boxer, Paul; Dubow, Eric; Huesmann, L. Rowell; Shikaki, Khalil; Landau, Simha; Gvirsman, Shira Dvir

    2016-01-01

    Ethno-political violence impacts thousands of youth and is associated with numerous negative outcomes. Yet little research examines adaptation to ethno-political violence over time or across multiple outcomes simultaneously. The present study examines longitudinal patterns of aggressive behavior and emotional distress as they co-occur among Palestinian (n=600) youth exposed to ethno-political violence over 3 years in 3 age cohorts (starting ages: 8, 11, 14). Findings indicate distinct profiles of aggressive behavior and emotional distress, and unique joint patterns. Further, youth among key joint profiles (e.g., high aggression-emotional desensitization) are more likely to endorse normative beliefs about aggression toward ethnic out-groups. This study offers a dynamic perspective on emotional and behavioral adaptation to ethno-political violence and the implications of those processes. PMID:27684400

  2. Global Acceleration of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat; Lara, Alejandro; Lepping, Ronald; Kaiser, Michael; Berdichevsky, Daniel; St. Cyr, O. Chris; Lazarus, Al

    1999-01-01

    Using the observed relation between speeds of coronal mass ejections (CMEs) near the Sun and in the solar wind, we estimate a global acceleration acting on the CMEs. Our study quantifies the qualitative results of Gosling [1997] and numerical simulations that CMEs at 1 AU with speeds closer to the solar wind. We found a linear relation between the global acceleration and the initial speed of the CMEs and the absolute value of the acceleration is similar to the slow solar wind acceleration. Our study naturally divides CMEs into fast and slow ones, the dividing line being the solar wind speed. Our results have important implications to space weather prediction models which need to incorporate this effect in estimating the CME arrival time at 1 AU. We show that the arrival times of CMEs at 1 AU are drastically different from the zero acceleration case.

  3. Mental energy: Assessing the motivation dimension.

    PubMed

    Barbuto, John E

    2006-07-01

    Content-based theories of motivation may best uti lize the meta-theory of work motivation. Process-based theories may benefit most from adopting Locke and Latham's goal-setting approaches and measures. Decision-making theories should utilize the measurement approach operationalized by Ilgen et al. Sustained effort theories should utilize similar approaches to those used in numerous studies of intrinsic motivation, but the measurement of which is typically observational or attitudinal. This paper explored the implications of the four approaches to studying motivation on the newly estab ished model of mental energy. The approach taken for examining motivation informs the measurement of mental energy. Specific recommendations for each approach were developed and provided. As a result of these efforts, it will now be possible to diagnose, measure, and experimentally test for changes in human motivation, which is one of the three major components of mental energy.

  4. Using fluorescent lipids in live zebrafish larvae: From imaging whole animal physiology to subcellular lipid trafficking.

    PubMed

    Anderson, J L; Carten, J D; Farber, S A

    2016-01-01

    Lipids serve essential functions in cells as signaling molecules, membrane components, and sources of energy. Defects in lipid metabolism are implicated in a number of pandemic human diseases, including diabetes, obesity, and hypercholesterolemia. Many aspects of how fatty acids and cholesterol are absorbed and processed by intestinal cells remain unclear and present a hurdle to developing approaches for disease prevention and treatment. Numerous studies have shown that the zebrafish is an excellent model for vertebrate lipid metabolism. In this chapter, we review commercially available fluorescent lipids that can be deployed in live zebrafish to better understand lipid signaling and metabolism. In this chapter, we present criteria one should consider when selecting specific fluorescent lipids for the study of digestive physiology or lipid metabolism in larval zebrafish. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. STS study on single crystal of noncentrosymmetric superconductor PbTaSe2

    NASA Astrophysics Data System (ADS)

    Ye, Zhiyang; Wu, Rui; Wang, Jihui; Liang, Xuejin; Mao, Hanqing; Zhao, Lingxiao; Chen, Genfu; Pan, Shuheng

    2015-03-01

    We report our low temperature scanning tunneling spectroscopic study on single crystals of noncentrosymmetric superconductor PbTaSe2. On the background of the normal state tunneling spectrum, a superconducting energy gap opens at a temperature below the bulk Tc = 3.7K. At t = 1.4K, the gap magnitude is estimated to be about 1meV. This energy gap is particle-hole symmetry and is homogeneous in space. Extrapolating the low energy part of the spectrum, we find that the low energy part of the gap spectrum is linear like ``V'' shape. We will present the results of the numerical fit with various gap functions of proposed possible pairing symmetry. We will also present our preliminary results of the magnetic field dependence measurement and discuss the implications of these observations.

  6. Tight-Binding Study of Polarons in Two-Dimensional Systems: Implications for Organic Field-Effect Transistor Materials

    NASA Astrophysics Data System (ADS)

    Lei, Jie

    2011-03-01

    In order to understand the electronic and transport properties of organic field-effect transistor (FET) materials, we theoretically studied the polarons in two-dimensional systems using a tight-binding model with the Holstein type and Su--Schrieffer--Heeger type electron--lattice couplings. By numerical calculations, it was found that a carrier accepts four kinds of localization, which are named the point polaron, two-dimensional polaron, one-dimensional polaron, and the extended state. The degree of localization is sensitive to the following parameters in the model: the strength and type of electron--lattice couplings, and the signs and relative magnitudes of transfer integrals. When a parameter set for a single-crystal phase of pentacene is applied within the Holstein model, a considerably delocalized hole polaron is found, consistent with the bandlike transport mechanism.

  7. Gravity and count probabilities in an expanding universe

    NASA Technical Reports Server (NTRS)

    Bouchet, Francois R.; Hernquist, Lars

    1992-01-01

    The time evolution of nonlinear clustering on large scales in cold dark matter, hot dark matter, and white noise models of the universe is investigated using N-body simulations performed with a tree code. Count probabilities in cubic cells are determined as functions of the cell size and the clustering state (redshift), and comparisons are made with various theoretical models. We isolate the features that appear to be the result of gravitational instability, those that depend on the initial conditions, and those that are likely a consequence of numerical limitations. More specifically, we study the development of skewness, kurtosis, and the fifth moment in relation to variance, the dependence of the void probability on time as well as on sparseness of sampling, and the overall shape of the count probability distribution. Implications of our results for theoretical and observational studies are discussed.

  8. Thermoacoustics of solids: A pathway to solid state engines and refrigerators

    NASA Astrophysics Data System (ADS)

    Hao, Haitian; Scalo, Carlo; Sen, Mihir; Semperlotti, Fabio

    2018-01-01

    Thermoacoustic oscillations have been one of the most exciting discoveries of the physics of fluids in the 19th century. Since its inception, scientists have formulated a comprehensive theoretical explanation of the basic phenomenon which has later found several practical applications to engineering devices. To date, all studies have concentrated on the thermoacoustics of fluid media where this fascinating mechanism was exclusively believed to exist. Our study shows theoretical and numerical evidence of the existence of thermoacoustic instabilities in solid media. Although the underlying physical mechanism exhibits some interesting similarities with its counterpart in fluids, the theoretical framework highlights relevant differences that have important implications on the ability to trigger and sustain the thermoacoustic response. This mechanism could pave the way to the development of highly robust and reliable solid-state thermoacoustic engines and refrigerators.

  9. From Scribbles to Scrabble: Preschool Children’s Developing Knowledge of Written Language

    PubMed Central

    Puranik, Cynthia S.; Lonigan, Christopher J.

    2011-01-01

    The purpose of this study was to concurrently examine the development of written language across several writing tasks and to investigate how writing features develop in preschool children. Emergent written language knowledge of 372 preschoolers was assessed using numerous writing tasks. The findings from this study indicate that children possess a great deal of writing knowledge before beginning school. Children appear to progress along a continuum from scribbling to conventional spelling, and this progression is linear and task dependent. There was clear evidence to support the claim that universal writing features develop before language-specific features. Children as young as 3 years possess knowledge regarding universal and language-specific writing features. There is substantial developmental continuity in literacy skills from the preschool period into early elementary grades. Implications of these findings on writing development are discussed. PMID:22448101

  10. Force-free electrodynamics in dynamical curved spacetimes

    NASA Astrophysics Data System (ADS)

    McWilliams, Sean

    2015-04-01

    We present results on our study of force-free electrodynamics in curved spacetimes. Specifically, we present several improvements to what has become the established set of evolution equations, and we apply these to study the nonlinear stability of analytically known force-free solutions for the first time. We implement our method in a new pseudo-spectral code built on top of the SpEC code for evolving dynamic spacetimes. Finally, we revisit these known solutions and attempt to clarify some interesting properties that render them analytically tractable. Finally, we preview some new work that similarly revisits the established approach to solving another problem in numerical relativity: the post-merger recoil from asymmetric gravitational-wave emission. These new results may have significant implications for the parameter dependence of recoils, and consequently on the statistical expectations for recoil velocities of merged systems.

  11. ISG15 in the tumorigenesis and treatment of cancer: An emerging role in malignancies of the digestive system

    PubMed Central

    Zuo, Chaohui; Sheng, Xinyi; Ma, Min; Xia, Man; Ouyang, Linda

    2016-01-01

    The interferon-stimulated gene 15 ubiquitin-like modifier (ISG15) encodes an IFN-inducible, ubiquitin-like protein. The ISG15 protein forms conjugates with numerous cellular proteins that are involved in a multitude of cellular functions, including interferon-induced immune responses and the regulation of cellular protein turnover. The expression of ISG15 and ISG15-mediated conjugation has been implicated in a wide range of human tumors and cancer cell lines, but the roles of ISG15 in tumorigenesis and responses to anticancer treatments remain largely unknown. In this review, we discuss the findings of recent studies with regard to the role of ISG15 pathways in cancers of the digestive system. PMID:27626310

  12. Dynamics of polymers: A mean-field theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fredrickson, Glenn H.; Materials Research Laboratory, University of California, Santa Barbara, California 93106; Department of Materials, University of California, Santa Barbara, California 93106

    2014-02-28

    We derive a general mean-field theory of inhomogeneous polymer dynamics; a theory whose form has been speculated and widely applied, but not heretofore derived. Our approach involves a functional integral representation of a Martin-Siggia-Rose (MSR) type description of the exact many-chain dynamics. A saddle point approximation to the generating functional, involving conditions where the MSR action is stationary with respect to a collective density field ρ and a conjugate MSR response field ϕ, produces the desired dynamical mean-field theory. Besides clarifying the proper structure of mean-field theory out of equilibrium, our results have implications for numerical studies of polymer dynamicsmore » involving hybrid particle-field simulation techniques such as the single-chain in mean-field method.« less

  13. The implications of the COBE diffuse microwave radiation results for cosmic strings

    NASA Technical Reports Server (NTRS)

    Bennett, David P.; Stebbins, Albert; Bouchet, Francois R.

    1992-01-01

    We compare the anisotropies in the cosmic microwave background radiation measured by the COBE experiment to those predicted by cosmic string theories. We use an analytic model for the Delta T/T power spectrum that is based on our previous numerical simulations of strings, under the assumption that cosmic strings are the sole source of the measured anisotropy. This implies a value for the string mass per unit length of 1.5 +/- 0.5 x 10 exp -6 C-squared/G. This is within the range of values required for cosmic strings to successfully seed the formation of large-scale structures in the universe. These results clearly encourage further studies of Delta T/T and large-scale structure in the cosmic string model.

  14. Periodically driven ergodic and many-body localized quantum systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ponte, Pedro; Department of Physics and Astronomy, University of Waterloo, ON N2L 3G1; Chandran, Anushya

    2015-02-15

    We study dynamics of isolated quantum many-body systems whose Hamiltonian is switched between two different operators periodically in time. The eigenvalue problem of the associated Floquet operator maps onto an effective hopping problem. Using the effective model, we establish conditions on the spectral properties of the two Hamiltonians for the system to localize in energy space. We find that ergodic systems always delocalize in energy space and heat up to infinite temperature, for both local and global driving. In contrast, many-body localized systems with quenched disorder remain localized at finite energy. We support our conclusions by numerical simulations of disorderedmore » spin chains. We argue that our results hold for general driving protocols, and discuss their experimental implications.« less

  15. Assessing the relationship between technology readiness and continuance intention in an E-appointment system: relationship quality as a mediator.

    PubMed

    Chen, Shih-Chih; Jong, Din; Lai, Min-Tsai

    2014-09-01

    Numerous types of self-service technologies have prevailed due to innovations in network and information technology. To hospitals, patient intentions to continue to use the e-appointment system are crucial. Previous investigations discussed only the relationships between the technology readiness of users and their continuance intentions, and ignored the most important mediator, relationship quality. This study explored the relationships among technology readiness, relationship quality, and continuance intention. The research results demonstrated that both optimism and innovativeness significantly and positively influenced continuance intention through the mediating effect of relationship quality. However, discomfort and insecurity hid not significantly influence relationship quality or continuance intention. Finally, theoretical contributions, managerial implications and future research directions were discussed.

  16. INA-Rxiv: The Missing Puzzle in Indonesia’s Scientific Publishing Workflow

    NASA Astrophysics Data System (ADS)

    Rahim, R.; Irawan, D. E.; Zulfikar, A.; Hardi, R.; Arliman S, L.; Gultom, E. R.; Ginting, G.; Wahyuni, S. S.; Mesran, M.; Mahjudin, M.; Saputra, I.; Waruwu, F. T.; Suginam, S.; Buulolo, E.; Abraham, J.

    2018-04-01

    INA-Rxiv is the first Indonesia preprint server marking the new development initiated by the open science community. This study aimed at describing the development of INA-Rxiv and its conversations. It usedanalyzer of Inarxiv.id, WhatsApp Group Analyzer, and Twitter Analytics as the tools for data analysis complemented with observation.The results showed that INA-Rxiv users are growing because of the numerous discussions in social media, e.g.WhatsApp,as well as some other positive response of writers who have been using INA- Rxiv. The perspective of growth mindset and the implication of INA-Rxiv movement for filling up the gap in accelerating scientific dissemination process are presented at the end of this article.

  17. A Practitioner-Driven Research Agenda for Syndromic Surveillance.

    PubMed

    Hopkins, Richard S; Tong, Catherine C; Burkom, Howard S; Akkina, Judy E; Berezowski, John; Shigematsu, Mika; Finley, Patrick D; Painter, Ian; Gamache, Roland; Vilas, Victor J Del Rio; Streichert, Laura C

    Syndromic surveillance has expanded since 2001 in both scope and geographic reach and has benefited from research studies adapted from numerous disciplines. The practice of syndromic surveillance continues to evolve rapidly. The International Society for Disease Surveillance solicited input from its global surveillance network on key research questions, with the goal of improving syndromic surveillance practice. A workgroup of syndromic surveillance subject matter experts was convened from February to June 2016 to review and categorize the proposed topics. The workgroup identified 12 topic areas in 4 syndromic surveillance categories: informatics, analytics, systems research, and communications. This article details the context of each topic and its implications for public health. This research agenda can help catalyze the research that public health practitioners identified as most important.

  18. Contaminated water as a source of Helicobacter pylori infection: A review

    PubMed Central

    Aziz, Ramy K.; Khalifa, Mohammed M.; Sharaf, Radwa R.

    2013-01-01

    Over the preceding years and to date, the definitive mode of human infection by Helicobacter pylori has remained largely unknown and has thus gained the interest of researchers around the world. Numerous studies investigated possible sources of transmission of this emerging carcinogenic pathogen that colonizes >50% of humans, in many of which contaminated water is mentioned as a major cause. The infection rate is especially higher in developing countries, where contaminated water, combined with social hardships and poor sanitary conditions, plays a key role. Judging from the growing global population and the changing climate, the rate is expected to rise. Here, we sum up the current views of the water transmission hypothesis, and we discuss its implications. PMID:26199743

  19. Effect of diastolic flow patterns on the function of the left ventricle

    NASA Astrophysics Data System (ADS)

    Seo, Jung Hee; Mittal, Rajat

    2013-11-01

    Direct numerical simulations are used to study the effect of intraventricular flow patterns on the pumping efficiency and the blood mixing and transport characteristics of the left ventricle. The simulations employ a geometric model of the left ventricle which is derived from contrast computed tomography. A variety of diastolic flow conditions are generated for a fixed ejection fraction in order to delineate the effect of flow patterns on ventricular performance. The simulations indicate that the effect of intraventricular blood flow pattern on the pumping power is physiologically insignificant. However, diastolic flow patterns have a noticeable effect on the blood mixing as well as the residence time of blood cells in the ventricle. The implications of these findings on ventricular function are discussed.

  20. Exploring the Concept of HIV-Related Stigma

    PubMed Central

    Florom-Smith, Aubrey L.; De Santis, Joseph P.

    2013-01-01

    BACKGROUND HIV infection is a chronic, manageable illness. Despite advances in the care and treatment of people living with HIV infection, HIV-related stigma remains a challenge to HIV testing, care, and prevention. Numerous studies have documented the impact of HIV-related stigma among various groups of people living with HIV infection, but the concept of HIV-related stigma remains unclear. PURPOSE Concept exploration of HIV-related stigma via an integrative literature review was conducted in order to examine the existing knowledge base of this concept. METHODS Search engines were employed to review the existing knowledge base of this concept. CONCLUSION After the integrative literature review, an analysis of HIV-related stigma emerged. Implications for future concept analysis, research, and practice are included. PMID:22861652

  1. ISG15 in the tumorigenesis and treatment of cancer: An emerging role in malignancies of the digestive system.

    PubMed

    Zuo, Chaohui; Sheng, Xinyi; Ma, Min; Xia, Man; Ouyang, Linda

    2016-11-08

    The interferon-stimulated gene 15 ubiquitin-like modifier (ISG15) encodes an IFN-inducible, ubiquitin-like protein. The ISG15 protein forms conjugates with numerous cellular proteins that are involved in a multitude of cellular functions, including interferon-induced immune responses and the regulation of cellular protein turnover. The expression of ISG15 and ISG15-mediated conjugation has been implicated in a wide range of human tumors and cancer cell lines, but the roles of ISG15 in tumorigenesis and responses to anticancer treatments remain largely unknown. In this review, we discuss the findings of recent studies with regard to the role of ISG15 pathways in cancers of the digestive system.

  2. Globalisation and Governance: Educational Policy Instruments and Regulatory Arrangements

    NASA Astrophysics Data System (ADS)

    Mok, Ka-Ho

    2005-07-01

    For more than a decade, the economic, social, political and cultural effects of globalisation have been central topics of debate. Those who see globalisation as a combination of economic transactions and worldwide telecommunications tend to believe that its impact is profound, inasmuch as it is fundamentally altering the way in which we live and creating hybrid cultural styles. No country is immune from the effects of globalisation, and controversy continues to reign about its positive and negative consequences. The present study identifies and examines numerous challenges posed by globalisation and their implications for educational restructuring, with special attention being given to new forms of governance; the relation between the state, the market and civil society; and governmental policy instruments for education.

  3. The Redox Chemistry and Chemical Biology of H2S, Hydropersulfides and Derived Species: Implications to Their Possible Biological Activity and Utility

    PubMed Central

    Ono, Katsuhiko; Akaike, Takaake; Sawa, Tomohiro; Kumagai, Yoshito; Wink, David A.; Tantillo, Dean J.; Hobbs, Adrian J.; Nagy, Peter; Xian, Ming; Lin, Joseph; Fukuto, Jon M.

    2014-01-01

    Hydrogen sulfide (H2S) is an endogenously generated and putative signaling/effector molecule. In spite of its numerous reported functions, the chemistry by which it elicits its functions is not understood. Moreover, recent studies allude to the existence of other sulfur species besides H2S that may play critical physiological roles. Herein, the basic chemical biology of H2S as well as other related or derived species is discussed and reviewed. A particular focus of this review are the per- and poly-sulfides which are likely in equilibrium with free H2S and which may be important biological effectors themselves. PMID:25229186

  4. Overview of Experimental and Clinical Findings regarding the Neuroprotective Effects of Cerebral Ischemic Postconditioning.

    PubMed

    Ma, Di; Feng, Liangshu; Deng, Fang; Feng, Jia-Chun

    2017-01-01

    Research on attenuating the structural and functional deficits observed following ischemia-reperfusion has become increasingly focused on the therapeutic potential of ischemic postconditioning. In recent years, various methods and animal models of ischemic postconditioning have been utilized. The results of these numerous studies have indicated that the mechanisms underlying the neuroprotective effects of ischemic postconditioning may involve reductions in the generation of free radicals and inhibition of calcium overload, as well as the release of endogenous active substances, alterations in membrane channel function, and activation of protein kinases. Here we review the novel discovery, mechanism, key factors, and clinical application of ischemic postconditioning and discuss its implications for future research and problem of clinical practice.

  5. Time-invariant PT product and phase locking in PT -symmetric lattice models

    NASA Astrophysics Data System (ADS)

    Joglekar, Yogesh N.; Onanga, Franck Assogba; Harter, Andrew K.

    2018-01-01

    Over the past decade, non-Hermitian, PT -symmetric Hamiltonians have been investigated as candidates for both a fundamental, unitary, quantum theory and open systems with a nonunitary time evolution. In this paper, we investigate the implications of the former approach in the context of the latter. Motivated by the invariance of the PT (inner) product under time evolution, we discuss the dynamics of wave-function phases in a wide range of PT -symmetric lattice models. In particular, we numerically show that, starting with a random initial state, a universal, gain-site location dependent locking between wave-function phases at adjacent sites occurs in the PT -symmetry-broken region. Our results pave the way towards understanding the physically observable implications of time invariants in the nonunitary dynamics produced by PT -symmetric Hamiltonians.

  6. Coronal Mass Ejections and their Implications for the Corona and Heliosphere

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro K.

    2008-01-01

    Coronal mass ejections (CMEs) are the largest and most energetic form of transients that connect the Sun to the heliosphere. They are critically important both for understanding the physical mechanisms of explosive solar activity and for predicting space weather. Furthermore they are an extreme example of how cross-scale coupling can play a critical role in determining the properties of a large-scale dynamical system. In this presentation CME theories are reviewed and the latest results from 3D numerical modeling of CME initiation propagation to the heliosphere are presented. In particular the focus is on the breakout model, but many of the results hold for the flux rope models as well. The implications of these results for understanding heliospheric structure and dynamics and for upcoming space missions will be discussed.

  7. Inhibitors of Protein Methyltransferases and Demethylases

    PubMed Central

    2017-01-01

    Post-translational modifications of histones by protein methyltransferases (PMTs) and histone demethylases (KDMs) play an important role in the regulation of gene expression and transcription and are implicated in cancer and many other diseases. Many of these enzymes also target various nonhistone proteins impacting numerous crucial biological pathways. Given their key biological functions and implications in human diseases, there has been a growing interest in assessing these enzymes as potential therapeutic targets. Consequently, discovering and developing inhibitors of these enzymes has become a very active and fast-growing research area over the past decade. In this review, we cover the discovery, characterization, and biological application of inhibitors of PMTs and KDMs with emphasis on key advancements in the field. We also discuss challenges, opportunities, and future directions in this emerging, exciting research field. PMID:28338320

  8. Targeted sorting of single virus-infected cells of the coccolithophore Emiliania huxleyi.

    PubMed

    Martínez Martínez, Joaquín; Poulton, Nicole J; Stepanauskas, Ramunas; Sieracki, Michael E; Wilson, William H

    2011-01-01

    Discriminating infected from healthy cells is the first step to understanding the mechanisms and ecological implications of viral infection. We have developed a method for detecting, sorting, and performing molecular analysis of individual, infected cells of the important microalga Emiliania huxleyi, based on known physiological responses to viral infection. Of three fluorescent dyes tested, FM 1-43 (for detecting membrane blebbing) gave the most unequivocal and earliest separation of cells. Furthermore, we were able to amplify the genomes of single infected cells using Multiple Displacement Amplification. This novel method to reliably discriminate infected from healthy cells in cultures will allow researchers to answer numerous questions regarding the mechanisms and implications of viral infection of E. huxleyi. The method may be transferable to other virus-host systems.

  9. Magnetic Field Applications in Semiconductor Crystal Growth and Metallurgy

    NASA Technical Reports Server (NTRS)

    Mazuruk, Konstantin; Ramachandran, Narayanan; Grugel, Richard; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    The Traveling Magnetic Field (TMF) technique, recently proposed to control meridional flow in electrically conducting melts, is reviewed. In particular, the natural convection damping capability of this technique has been numerically demonstrated with the implication of significantly improving crystal quality. Advantages of the traveling magnetic field, in comparison to the more mature rotating magnetic field method, are discussed. Finally, results of experiments with mixing metallic alloys in long ampoules using TMF is presented

  10. Nursing education trends: future implications and predictions.

    PubMed

    Valiga, Theresa M Terry

    2012-12-01

    This article examines current trends in nursing education and proposes numerous transformations needed to ensure that programs are relevant, fully engage learners, reflect evidence-based teaching practices, and are innovative. Such program characteristics are essential if we are to graduate nurses who can practice effectively in today's complex, ambiguous, ever-changing health care environments and who are prepared to practice in and, indeed, shape tomorrow's unknown practice environments. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. State and Local Governments: Fiscal Pressures Could Have Implications for Future Delivery of Intergovernmental Programs. Report to the Ranking Member, Committee on the Budget, House of Representatives. GAO-10-899

    ERIC Educational Resources Information Center

    Czerwinski, Stanley J.

    2010-01-01

    State and local governments work in partnership with the federal government to implement numerous intergovernmental programs. Fiscal pressures for state and local governments may exist when spending is expected to outpace revenues for the long term. GAO (Government Accountability Office) was asked to examine (1) the long-term fiscal pressures…

  12. Numerical examination of the factors controlling DNAPL migration through a single fracture.

    PubMed

    Reynolds, D A; Kueper, B H

    2002-01-01

    The migration of five dense nonaqueous phase liquids (DNAPLs) through a single fracture in a clay aquitard was numerically simulated with the use of a compositional simulator. The effects of fracture aperture, fracture dip, matrix porosity, and matrix organic carbon content on the migration of chlorobenzene, 1,2-dichloroethylene, trichloroethylene, tetra-chloroethylene, and 1,2-dibromoethane were examined. Boundary conditions were chosen such that DNAPL entry into the system was allowed to vary according to the stresses applied. The aperture is the most important factor of those studied controlling the migration rate of DNAPL through a single fracture embedded in a clay matrix. Loss of mass to the matrix through diffusion does not significantly retard the migration rate of the DNAPL, particularly in larger aperture fractures (e.g., 50 microm). With time, the ratio of diffusive loss to the matrix to DNAPL flux into the fracture approaches an asymptotic value lower than unity. The implication is that matrix diffusion cannot arrest the migration of DNAPL in a single fracture. The complex relationships between density, viscosity, and solubility that, to some extent, govern the migration of DNAPL through these systems prevent accurate predictions without the use of numerical models. The contamination potential of the migrating DNAPL is significantly increased through the transfer of mass to the matrix. The occurrence of opposite concentration gradients within the matrix can cause dissolved phase contamination to exist in the system for more than 1000 years after the DNAPL has been completely removed from the fracture.

  13. Optimizing withdrawal from drinking water reservoirs to reduce downstream temperature pollution and reservoir hypoxia.

    PubMed

    Weber, M; Rinke, K; Hipsey, M R; Boehrer, B

    2017-07-15

    Sustainable management of drinking water reservoirs requires balancing the demands of water supply whilst minimizing environmental impact. This study numerically simulates the effect of an improved withdrawal scheme designed to alleviate the temperature pollution downstream of a reservoir. The aim was to identify an optimal withdrawal strategy such that water of a desirable discharge temperature can be supplied downstream without leading to unacceptably low oxygen concentrations within the reservoir. First, we calibrated a one-dimensional numerical model for hydrodynamics and oxygen dynamics (GLM-AED2), verifying that the model reproduced water temperatures and hypolimnetic dissolved oxygen concentrations accurately over a 5 year period. Second, the model was extended to include an adaptive withdrawal functionality, allowing for a prescribed withdrawal temperature to be found, with the potential constraint of hypolimnetic oxygen concentration. Scenario simulations on epi-/metalimnetic withdrawal demonstrate that the model is able to autonomously determine the best withdrawal height depending on the thermal structure and the hypolimnetic oxygen concentration thereby optimizing the ability to supply a desirable discharge temperature to the downstream river during summer. This new withdrawal strategy also increased the hypolimnetic raw water volume to be used for drinking water supply, but reduced the dissolved oxygen concentrations in the deep and cold water layers (hypolimnion). Implications of the results for reservoir management are discussed and the numerical model is provided for operators as a simple and efficient tool for optimizing the withdrawal strategy within different reservoir contexts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Methane Recovery from Hydrate-bearing Sediments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    J. Carlos Santamarina; Costas Tsouris

    2011-04-30

    Gas hydrates are crystalline compounds made of gas and water molecules. Methane hydrates are found in marine sediments and permafrost regions; extensive amounts of methane are trapped in the form of hydrates. Methane hydrate can be an energy resource, contribute to global warming, or cause seafloor instability. This study placed emphasis on gas recovery from hydrate bearing sediments and related phenomena. The unique behavior of hydrate-bearing sediments required the development of special research tools, including new numerical algorithms (tube- and pore-network models) and experimental devices (high pressure chambers and micromodels). Therefore, the research methodology combined experimental studies, particle-scale numerical simulations,more » and macro-scale analyses of coupled processes. Research conducted as part of this project started with hydrate formation in sediment pores and extended to production methods and emergent phenomena. In particular, the scope of the work addressed: (1) hydrate formation and growth in pores, the assessment of formation rate, tensile/adhesive strength and their impact on sediment-scale properties, including volume change during hydrate formation and dissociation; (2) the effect of physical properties such as gas solubility, salinity, pore size, and mixed gas conditions on hydrate formation and dissociation, and it implications such as oscillatory transient hydrate formation, dissolution within the hydrate stability field, initial hydrate lens formation, and phase boundary changes in real field situations; (3) fluid conductivity in relation to pore size distribution and spatial correlation and the emergence of phenomena such as flow focusing; (4) mixed fluid flow, with special emphasis on differences between invading gas and nucleating gas, implications on relative gas conductivity for reservoir simulations, and gas recovery efficiency; (5) identification of advantages and limitations in different gas production strategies with emphasis; (6) detailed study of CH4-CO2 exchange as a unique alternative to recover CH4 gas while sequestering CO2; (7) the relevance of fines in otherwise clean sand sediments on gas recovery and related phenomena such as fines migration and clogging, vuggy structure formation, and gas-driven fracture formation during gas production by depressurization.« less

  15. Crashworthiness analysis using advanced material models in DYNA3D

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Logan, R.W.; Burger, M.J.; McMichael, L.D.

    1993-10-22

    As part of an electric vehicle consortium, LLNL and Kaiser Aluminum are conducting experimental and numerical studies on crashworthy aluminum spaceframe designs. They have jointly explored the effect of heat treat on crush behavior and duplicated the experimental behavior with finite-element simulations. The major technical contributions to the state of the art in numerical simulation arise from the development and use of advanced material model descriptions for LLNL`s DYNA3D code. Constitutive model enhancements in both flow and failure have been employed for conventional materials such as low-carbon steels, and also for lighter weight materials such as aluminum and fiber compositesmore » being considered for future vehicles. The constitutive model enhancements are developed as extensions from LLNL`s work in anisotropic flow and multiaxial failure modeling. Analysis quality as a function of level of simplification of material behavior and mesh is explored, as well as the penalty in computation cost that must be paid for using more complex models and meshes. The lightweight material modeling technology is being used at the vehicle component level to explore the safety implications of small neighborhood electric vehicles manufactured almost exclusively from these materials.« less

  16. Nuclear speckles: molecular organization, biological function and role in disease

    PubMed Central

    Galganski, Lukasz; Urbanek, Martyna O.

    2017-01-01

    Abstract The nucleoplasm is not homogenous; it consists of many types of nuclear bodies, also known as nuclear domains or nuclear subcompartments. These self-organizing structures gather machinery involved in various nuclear activities. Nuclear speckles (NSs) or splicing speckles, also called interchromatin granule clusters, were discovered as sites for splicing factor storage and modification. Further studies on transcription and mRNA maturation and export revealed a more general role for splicing speckles in RNA metabolism. Here, we discuss the functional implications of the localization of numerous proteins crucial for epigenetic regulation, chromatin organization, DNA repair and RNA modification to nuclear speckles. We highlight recent advances suggesting that NSs facilitate integrated regulation of gene expression. In addition, we consider the influence of abundant regulatory and signaling proteins, i.e. protein kinases and proteins involved in protein ubiquitination, phosphoinositide signaling and nucleoskeletal organization, on pre-mRNA synthesis and maturation. While many of these regulatory proteins act within NSs, direct evidence for mRNA metabolism events occurring in NSs is still lacking. NSs contribute to numerous human diseases, including cancers and viral infections. In addition, recent data have demonstrated close relationships between these structures and the development of neurological disorders. PMID:28977640

  17. Dispersion, dissipation and refraction of shock waves in acoustically treated turbofan inlets

    NASA Astrophysics Data System (ADS)

    Prasad, Dilip; Li, Ding; A. Topol, David

    2015-09-01

    This paper describes a numerical investigation of the effects of the inlet duct liner on the acoustics of a high-bypass ratio turbofan rotor operating at supersonic tip relative flow conditions. The near field of the blade row is then composed of periodic shocks that evolve spatially both because of the varying mean flow and because of the presence of acoustic treatment. The evolution of this shock system is studied using a Computational Fluid Dynamics-based method incorporating a wall impedance boundary condition. The configuration examined is representative of a fan operating near the takeoff condition. The behavior of the acoustic power and the associated waveforms reveal that significant dispersion occurs to the extent that there are no shocks in the perturbation field leaving the entrance plane of the duct. The effect of wave refraction due to the high degree of shear in the mean flow near the entrance plane of the inlet is examined, and numerical experiments are conducted to show that the incorporation of liners in this region can be highly beneficial. The implications of these results for the design of aircraft engine acoustic liners are discussed.

  18. Dielectrophoretic levitation in the presence of shear flow: implications for colloidal fouling of filtration membranes.

    PubMed

    Molla, Shahnawaz; Bhattacharjee, Subir

    2007-10-09

    The ability of dielectrophoretic (DEP) forces created using a microelectrode array to levitate particles in a colloidal suspension is studied experimentally and theoretically. The experimental system employs microfabricated electrode arrays on a glass substrate to apply repulsive DEP forces on polystyrene latex particles suspended in an aqueous medium. A numerical model based on the convection-diffusion-migration equation is presented to calculate the concentration distribution of colloidal particles in shear flow under the influence of a repulsive DEP force field. The results obtained from the numerical simulations are compared against trajectory analysis results and experimental data. The results indicate that by incorporating ac electric field-induced DEP forces in a shear flow, particle accumulation and deposition on the flow channel surfaces can be significantly reduced or even completely averted. The mathematical model is then used to indicate how the deposition behavior is modified in the presence of a permeable substrate, representative of tangential flow membrane filtration operations. The results indicate that the repulsive dielectrophoretic (DEP) forces imparted to the particles suspended in the feed can be employed to mitigate membrane fouling in a cross-flow filtration process.

  19. Development and Applications of the GOES Sounder Products

    NASA Astrophysics Data System (ADS)

    Li, Jun; Menzel, W. P.; Li, Z.; Wade, G.; Schmit, T. J.; Li, J. L.; Aune, R.; Schreiner, A. J.; Schmidt, C. C.; Genkova, I.

    Since 1994 a new generation of Geostationary Operational Environmental Satellite GOES Sounders GOES-8 9 10 11 12 has been measuring radiances in 18 infrared spectral bands ranging from approximately 3 7um - 14 7 um This data has been used to provide atmospheric sounding and cloud products for meteorological applications on an hourly basis over North America and adjacent oceanic regions The products include atmospheric temperature and moisture profiles total precipitable water cloud-top pressure water-vapor tracked winds etc Products are generated operationally by NOAA NESDIS in Washington D C Some Sounder products including total column ozone are also produced at the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin-Madison Applications of those products include nowcasting and forecasting of weather events assimilation of cloud products into regional numerical forecast models and monitoring of temperature and moisture changes during active convective periods The impact of GOES Sounder products on numerical model forecasts will be demonstrated Furthermore recent improvements to several of the products have been made by taking into account the GOES Sounder temporal and spatial information within the processing algorithms These improvements and implications thereof will be presented and discussed

  20. Identification of differentially regulated transcripts in mouse striatum following methamphetamine treatment--an oligonucleotide microarray approach.

    PubMed

    Thomas, David M; Francescutti-Verbeem, Dina M; Liu, Xiuli; Kuhn, Donald M

    2004-01-01

    Methamphetamine is an addictive drug of abuse that can produce neurotoxic effects in dopamine nerve endings of the striatum. The purpose of this study was to identify new genes that may play a role in the highly complex cascade of events associated with methamphetamine intoxication. Using Affymetrix oligonucleotide arrays, 12 488 genes were simultaneously interrogated and there were 152 whose expression levels were changed following methamphetamine treatment. The genes are grouped into broad functional categories with inflammatory/immune response elements, receptor/signal transduction components and ion channel/transport proteins among the most populated. Many genes within these categories can be linked to ion regulation and apoptosis, both of which have been implicated in methamphetamine toxicity, and numerous factors associated with microglial activation emerged with significant changes in expression. For example, brain-derived neurotrophic factor (BDNF), chemokine (C-C) receptor 6 (CCr6) and numerous chemokine transcripts were increased or decreased in expression more than 2.8-fold. These results point to activated microglia as a potential source of the reactive oxygen/nitrogen species and cytokines that have been previously associated with methamphetamine toxicity and other neurotoxic conditions.

  1. Mechanisms of interactive specialization and emergence of functional brain circuits supporting cognitive development in children

    NASA Astrophysics Data System (ADS)

    Battista, Christian; Evans, Tanya M.; Ngoon, Tricia J.; Chen, Tianwen; Chen, Lang; Kochalka, John; Menon, Vinod

    2018-01-01

    Cognitive development is thought to depend on the refinement and specialization of functional circuits over time, yet little is known about how this process unfolds over the course of childhood. Here we investigated growth trajectories of functional brain circuits and tested an interactive specialization model of neurocognitive development which posits that the refinement of task-related functional networks is driven by a shared history of co-activation between cortical regions. We tested this model in a longitudinal cohort of 30 children with behavioral and task-related functional brain imaging data at multiple time points spanning childhood and adolescence, focusing on the maturation of parietal circuits associated with numerical problem solving and learning. Hierarchical linear modeling revealed selective strengthening as well as weakening of functional brain circuits. Connectivity between parietal and prefrontal cortex decreased over time, while connectivity within posterior brain regions, including intra-hemispheric and inter-hemispheric parietal connectivity, as well as parietal connectivity with ventral temporal occipital cortex regions implicated in quantity manipulation and numerical symbol recognition, increased over time. Our study provides insights into the longitudinal maturation of functional circuits in the human brain and the mechanisms by which interactive specialization shapes children's cognitive development and learning.

  2. Predictability and Quantification of Complex Groundwater Table Dynamics Driven by Irregular Surface Water Fluctuations

    NASA Astrophysics Data System (ADS)

    Xin, Pei; Wang, Shen S. J.; Shen, Chengji; Zhang, Zeyu; Lu, Chunhui; Li, Ling

    2018-03-01

    Shallow groundwater interacts strongly with surface water across a quarter of global land area, affecting significantly the terrestrial eco-hydrology and biogeochemistry. We examined groundwater behavior subjected to unimodal impulse and irregular surface water fluctuations, combining physical experiments, numerical simulations, and functional data analysis. Both the experiments and numerical simulations demonstrated a damped and delayed response of groundwater table to surface water fluctuations. To quantify this hysteretic shallow groundwater behavior, we developed a regression model with the Gamma distribution functions adopted to account for the dependence of groundwater behavior on antecedent surface water conditions. The regression model fits and predicts well the groundwater table oscillations resulting from propagation of irregular surface water fluctuations in both laboratory and large-scale aquifers. The coefficients of the Gamma distribution function vary spatially, reflecting the hysteresis effect associated with increased amplitude damping and delay as the fluctuation propagates. The regression model, in a relatively simple functional form, has demonstrated its capacity of reproducing high-order nonlinear effects that underpin the surface water and groundwater interactions. The finding has important implications for understanding and predicting shallow groundwater behavior and associated biogeochemical processes, and will contribute broadly to studies of groundwater-dependent ecology and biogeochemistry.

  3. The formation of granular fronts in debris flow - A combined experimental-numerical study

    NASA Astrophysics Data System (ADS)

    Leonardi, Alessandro; Cabrera, Miguel; Wittel, Falk K.; Kaitna, Roland; Mendoza, Miller; Wu, Wei; Herrmann, Hans J.

    2015-04-01

    Granular fronts are amongst the most spectacular features of debris flows, and are also one of the reasons why such events are associated with a strong destructive power. They are usually believed to be the result of the convective mechanism of the debris flow, combined with internal size segregation of the grains. However, the knowledge about the conditions leading to the formation of a granular front is not up to date. We present a combined study with experimental and numerical features that aims at providing insight into the phenomenon. A stationary, long-lived avalanche is created within a rotating drum. In order to mimic the composition of an actual debris flow, the material is composed by a mixture of a plastic fluid, obtained with water and kaolin powder, and a collection of monodisperse spherical particles heavier than the fluid. Tuning the material properties and the drum settings, we are able to reproduce and control the formation of a granular front. To gain insight into the internal mechanism, the same scenario is replicated in a numerical environment, using a coupling technique between a discrete solver for the particles, the Discrete Element Method, and a continuum solver for the plastic fluid, the Lattice-Boltzmann Method. The simulations compare well with the experiments, and show the internal reorganization of the material transport. The formation of a granular front is shown to be favored by a higher drum rotational speed, which in turn forces a higher shear rate on the particles, breaks their internal organization, and contrasts their natural tendency to settle. Starting from dimensional analysis, we generalize the obtained results and are able to draw implications for debris flow research.

  4. Oxidative Stress and Antioxidants in the Diagnosis and Therapy of Periodontitis

    PubMed Central

    Tóthová, L'ubomíra; Celec, Peter

    2017-01-01

    Oxidative stress has been implicated in the pathogenesis of numerous diseases. However, large interventional studies with antioxidants failed to show benefits in the prevention or treatment of cardiovascular diseases, cancer, or diabetes mellitus. Numerous clinical studies have confirmed the association of oxidative stress markers and periodontitis. Technical and biological variability is high for most of the analyzed markers and none of them seems to be optimal for routine clinical use. In a research setting, analysis of a palette of oxidative stress markers is needed to cover lipid peroxidation, protein oxidation, and the antioxidant status. The source of reactive oxygen species and their role in the pathogenesis of periodontitis remains unclear. Interventional experiments indicate that oxidative stress might be more than just a simple consequence of the inflammation. Small studies have confirmed that some antioxidants could have therapeutic value at least as an addition to the standard non-surgical treatment of periodontitis. A clear evidence for the efficiency of antioxidant treatment in large patient cohorts is lacking. Potentially, because lowering of oxidative stress markers might be a secondary effect of anti-inflammatory or antibacterial agents. As the field of research of oxidative stress in periodontitis gains attraction and the number of relevant published papers is increasing a systematic overview of the conducted observational and interventional studies is needed. This review summarizes the currently available literature linking oxidative stress and periodontitis and points toward the potential of adjuvant antioxidant treatment, especially in cases where standard treatment fails to improve the periodontal status. PMID:29311982

  5. Advances in immunotherapeutic strategies for colorectal cancer commentary on: tumoral immune cell exploitation in colorectal cancer metastases can be targeted effectively by anti-CCR5 therapy in cancer patients by Halama et al.

    PubMed

    Deming, Dustin A

    2016-01-01

    Colorectal cancer is a leading cause of cancer-related death in the United States, despite recent advances in treatment strategies. The immune system has been implicated in the pathogenesis of colorectal cancer, with numerous studies identifying either antagonistic or pro-tumorigenic effects of infiltrating immune cells. Therapeutic strategies harnessing the immune system to target cancers have evolved expediently over the last 5 years, especially the use of checkpoint inhibitors. Recently, a subset of patients whose colorectal cancers harbor a deficiency in mismatch repair proteins have demonstrated dramatic and durable response to checkpoint blockade. Unfortunately, the vast majority of colorectal cancers are mismatch repair proficient and resistant to these inhibitors. The tumor microenvironment has been implicated in the resistance to checkpoint block and ways to overcome these resistance mechanisms would be a major advance for the treatment of colorectal cancer. Here we provide commentary on a manuscript from Halama et al. examining CCL5/CCR5 as an immune biomarker and the potential role of anti-CCR5 agents for the treatment of patients with colorectal cancer.

  6. Formation of an Oceanic Transform Fault During Continental Rifting

    NASA Astrophysics Data System (ADS)

    Illsley-Kemp, F.; Bull, J. M.; Keir, D.; Gerya, T.; Pagli, C.; Gernon, T.; Ayele, A.; Goitom, B.; Hammond, J. O. S.; Kendall, J. M.

    2017-12-01

    We integrate evidence from surface faults, geodetic measurements, local seismicity, and 3D numerical modelling of the subaerial Afar continental rift to show that an oceanic-style transform fault is forming during the final stages of continental breakup. Transform faults are a fundamental tenet of plate tectonics, connecting offset extensional segments of mid-ocean ridges, and are vital in palaeotectonic reconstructions of passive margins. The current consensus is that transform faults initiate after the onset of seafloor spreading. However this inference has been difficult to test given the lack of observations of transform fault formation. We present the first direct observation of transform fault initiation, and shed unprecedented light on their formation mechanisms. We demonstrate that they originate during late-stage continental rifting, earlier in the rifting cycle than previously thought. Our results have important implications for reconstructing the breakup history of the continents. Palaeotectonic reconstructions that use transform fault terminations as an indicator of the continent-ocean boundary may have placed the continent-ocean boundary landward of its true location. This will have led to an overestimation of the age of continental breakup of between 8-18 Myr. Our results therefore have significant implications for studies that rely on accurate dating of continental breakup events.

  7. Auxins and tropisms

    NASA Technical Reports Server (NTRS)

    Muday, G. K.; Brown, C. S. (Principal Investigator)

    2001-01-01

    Differential growth of plants in response to the changes in the light and gravity vectors requires a complex signal transduction cascade. Although many of the details of the mechanisms by which these differential growth responses are induced are as yet unknown, auxin has been implicated in both gravitropism and phototropism. Specifically, the redistribution of auxin across gravity or light-stimulated tissues has been detected and shown to be required for this process. The approaches by which auxin has been implicated in tropisms include isolation of mutants altered in auxin transport or response with altered gravitropic or phototropic response, identification of auxin gradients with radiolabeled auxin and auxin-inducible gene reporter systems, and by use of inhibitors of auxin transport that block gravitropism and phototropism. Proteins that transport auxin have been identified and the mechanisms which determine auxin transport polarity have been explored. In addition, recent evidence that reversible protein phosphorylation controls this process is summarized. Finally, the data in support of several hypotheses for mechanisms by which auxin transport could be differentially regulated during gravitropism are examined. Although many details of the mechanisms by which plants respond to gravity and light are not yet clear, numerous recent studies demonstrate the role of auxin in these processes.

  8. Feedforward Inhibition and Synaptic Scaling – Two Sides of the Same Coin?

    PubMed Central

    Lücke, Jörg

    2012-01-01

    Feedforward inhibition and synaptic scaling are important adaptive processes that control the total input a neuron can receive from its afferents. While often studied in isolation, the two have been reported to co-occur in various brain regions. The functional implications of their interactions remain unclear, however. Based on a probabilistic modeling approach, we show here that fast feedforward inhibition and synaptic scaling interact synergistically during unsupervised learning. In technical terms, we model the input to a neural circuit using a normalized mixture model with Poisson noise. We demonstrate analytically and numerically that, in the presence of lateral inhibition introducing competition between different neurons, Hebbian plasticity and synaptic scaling approximate the optimal maximum likelihood solutions for this model. Our results suggest that, beyond its conventional use as a mechanism to remove undesired pattern variations, input normalization can make typical neural interaction and learning rules optimal on the stimulus subspace defined through feedforward inhibition. Furthermore, learning within this subspace is more efficient in practice, as it helps avoid locally optimal solutions. Our results suggest a close connection between feedforward inhibition and synaptic scaling which may have important functional implications for general cortical processing. PMID:22457610

  9. Investigating Interruptions: Implications for Flightdeck Performance

    NASA Technical Reports Server (NTRS)

    Latorella, Kara A.

    1999-01-01

    A fundamental aspect of multiple task management is attending to new stimuli and integrating associated task requirements into an ongoing task set; this is "interruption management" (IM). Anecdotal evidence and field studies indicate the frequency and consequences of interruptions, however experimental investigations of mechanisms influencing IM are scarce. Interruptions on commercial flightdecks are numerous, of various forms, and have been cited as contributing factors in many aviation incident and accident reports. This research grounds an experimental investigation of flightdeck interruptions in a proposed IM stage model. This model organizes basic research, identifies influencing mechanisms, and suggests appropriate dependent measures for IM. Fourteen airline pilots participated in a flightdeck simulation experiment to investigate the general effects of performing an interrupting task and interrupted procedure, and the effects of specific task factors: (1) modality; (2) embeddedness, or goal-level, of an interruption; (3) strength of association, or coupling-strength, between interrupted tasks; (4) semantic similarity; and (5) environmental stress. General effects of interruptions were extremely robust. All individual task factors significantly affected interruption management, except "similarity." Results extend the Interruption Management model, and are interpreted for their implications for interrupted flightdeck performance and intervention strategies for mitigating their effects on the flightdeck.

  10. Enteric pathogen-plant interactions: molecular connections leading to colonization and growth and implications for food safety.

    PubMed

    Martínez-Vaz, Betsy M; Fink, Ryan C; Diez-Gonzalez, Francisco; Sadowsky, Michael J

    2014-01-01

    Leafy green vegetables have been identified as a source of foodborne illnesses worldwide over the past decade. Human enteric pathogens, such as Escherichia coli O157:H7 and Salmonella, have been implicated in numerous food poisoning outbreaks associated with the consumption of fresh produce. An understanding of the mechanisms responsible for the establishment of pathogenic bacteria in or on vegetable plants is critical for understanding and ameliorating this problem as well as ensuring the safety of our food supply. While previous studies have described the growth and survival of enteric pathogens in the environment and also the risk factors associated with the contamination of vegetables, the molecular events involved in the colonization of fresh produce by enteric pathogens are just beginning to be elucidated. This review summarizes recent findings on the interactions of several bacterial pathogens with leafy green vegetables. Changes in gene expression linked to the bacterial attachment and colonization of plant structures are discussed in light of their relevance to plant-microbe interactions. We propose a mechanism for the establishment and association of enteric pathogens with plants and discuss potential strategies to address the problem of foodborne illness linked to the consumption of leafy green vegetables.

  11. Feedforward inhibition and synaptic scaling--two sides of the same coin?

    PubMed

    Keck, Christian; Savin, Cristina; Lücke, Jörg

    2012-01-01

    Feedforward inhibition and synaptic scaling are important adaptive processes that control the total input a neuron can receive from its afferents. While often studied in isolation, the two have been reported to co-occur in various brain regions. The functional implications of their interactions remain unclear, however. Based on a probabilistic modeling approach, we show here that fast feedforward inhibition and synaptic scaling interact synergistically during unsupervised learning. In technical terms, we model the input to a neural circuit using a normalized mixture model with Poisson noise. We demonstrate analytically and numerically that, in the presence of lateral inhibition introducing competition between different neurons, Hebbian plasticity and synaptic scaling approximate the optimal maximum likelihood solutions for this model. Our results suggest that, beyond its conventional use as a mechanism to remove undesired pattern variations, input normalization can make typical neural interaction and learning rules optimal on the stimulus subspace defined through feedforward inhibition. Furthermore, learning within this subspace is more efficient in practice, as it helps avoid locally optimal solutions. Our results suggest a close connection between feedforward inhibition and synaptic scaling which may have important functional implications for general cortical processing.

  12. Categorisation of Colour Terms Using New Validation Tools: A Case Study and Implications

    PubMed Central

    Arbab, Shabnam; Brindle, Jonathan A.; Matusiak, Barbara S.; Klöckner, Christian A.

    2018-01-01

    This article elaborates on the results of a field experiment conducted among speakers of the Chakali language, spoken in northern Ghana. In the original study, the Color-aid Corporation Chart was used to perform the focal task in which consultants were asked to point at a single colour tile on the chart. However, data from the focal task could not be analysed since the Color-aid tiles had not yet been converted into numerical values set forth by the Commission internationale de l’éclairage (CIE). In this study, the full set of 314 Color-aid tiles were measured for chromaticity and converted into the CIE values at the Daylight Laboratory of the Norwegian University of Science and Technology. This article presents the conversion methodology and makes the results of the measurements, which are available in the Online Appendix. We argue that some visual-perception terms cannot be reliably ascribed to colour categories established by the Color-aid Corporation. This suggests that the ideophonic expressions in the dataset do not denote ‘colours’, as categorised in the Color-aid system, as it was impossible to average the consultants’ data into a CIE chromaticity diagram, illustrate the phenomena on the Natural Colour System (NCS) Circle and Triangle diagrams, and conduct a statistical analysis. One of the implications of this study is that a line between a visual-perception term and a colour term could be systematically established using a method with predefined categorical thresholds. PMID:29755718

  13. Categorisation of Colour Terms Using New Validation Tools: A Case Study and Implications.

    PubMed

    Arbab, Shabnam; Brindle, Jonathan A; Matusiak, Barbara S; Klöckner, Christian A

    2018-01-01

    This article elaborates on the results of a field experiment conducted among speakers of the Chakali language, spoken in northern Ghana. In the original study, the Color-aid Corporation Chart was used to perform the focal task in which consultants were asked to point at a single colour tile on the chart. However, data from the focal task could not be analysed since the Color-aid tiles had not yet been converted into numerical values set forth by the Commission internationale de l'éclairage (CIE). In this study, the full set of 314 Color-aid tiles were measured for chromaticity and converted into the CIE values at the Daylight Laboratory of the Norwegian University of Science and Technology. This article presents the conversion methodology and makes the results of the measurements, which are available in the Online Appendix. We argue that some visual-perception terms cannot be reliably ascribed to colour categories established by the Color-aid Corporation. This suggests that the ideophonic expressions in the dataset do not denote 'colours', as categorised in the Color-aid system, as it was impossible to average the consultants' data into a CIE chromaticity diagram, illustrate the phenomena on the Natural Colour System (NCS) Circle and Triangle diagrams, and conduct a statistical analysis. One of the implications of this study is that a line between a visual-perception term and a colour term could be systematically established using a method with predefined categorical thresholds.

  14. Solidification of a binary alloy: Finite-element, single-domain simulation and new benchmark solutions

    NASA Astrophysics Data System (ADS)

    Le Bars, Michael; Worster, M. Grae

    2006-07-01

    A finite-element simulation of binary alloy solidification based on a single-domain formulation is presented and tested. Resolution of phase change is first checked by comparison with the analytical results of Worster [M.G. Worster, Solidification of an alloy from a cooled boundary, J. Fluid Mech. 167 (1986) 481-501] for purely diffusive solidification. Fluid dynamical processes without phase change are then tested by comparison with previous numerical studies of thermal convection in a pure fluid [G. de Vahl Davis, Natural convection of air in a square cavity: a bench mark numerical solution, Int. J. Numer. Meth. Fluids 3 (1983) 249-264; D.A. Mayne, A.S. Usmani, M. Crapper, h-adaptive finite element solution of high Rayleigh number thermally driven cavity problem, Int. J. Numer. Meth. Heat Fluid Flow 10 (2000) 598-615; D.C. Wan, B.S.V. Patnaik, G.W. Wei, A new benchmark quality solution for the buoyancy driven cavity by discrete singular convolution, Numer. Heat Transf. 40 (2001) 199-228], in a porous medium with a constant porosity [G. Lauriat, V. Prasad, Non-darcian effects on natural convection in a vertical porous enclosure, Int. J. Heat Mass Transf. 32 (1989) 2135-2148; P. Nithiarasu, K.N. Seetharamu, T. Sundararajan, Natural convective heat transfer in an enclosure filled with fluid saturated variable porosity medium, Int. J. Heat Mass Transf. 40 (1997) 3955-3967] and in a mixed liquid-porous medium with a spatially variable porosity [P. Nithiarasu, K.N. Seetharamu, T. Sundararajan, Natural convective heat transfer in an enclosure filled with fluid saturated variable porosity medium, Int. J. Heat Mass Transf. 40 (1997) 3955-3967; N. Zabaras, D. Samanta, A stabilized volume-averaging finite element method for flow in porous media and binary alloy solidification processes, Int. J. Numer. Meth. Eng. 60 (2004) 1103-1138]. Finally, new benchmark solutions for simultaneous flow through both fluid and porous domains and for convective solidification processes are presented, based on the similarity solutions in corner-flow geometries recently obtained by Le Bars and Worster [M. Le Bars, M.G. Worster, Interfacial conditions between a pure fluid and a porous medium: implications for binary alloy solidification, J. Fluid Mech. (in press)]. Good agreement is found for all tests, hence validating our physical and numerical methods. More generally, the computations presented here could now be considered as standard and reliable analytical benchmarks for numerical simulations, specifically and independently testing the different processes underlying binary alloy solidification.

  15. NUMERICAL SIMULATIONS OF THERMOHALINE CONVECTION: IMPLICATIONS FOR EXTRA-MIXING IN LOW-MASS RGB STARS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Denissenkov, Pavel A., E-mail: pavel.denisenkov@gmail.co

    2010-11-01

    Low-mass stars are known to experience extra-mixing in their radiative zones on the red giant branch (RGB) above the bump luminosity. To determine if the salt-fingering transport of chemical composition driven by {sup 3}He burning is efficient enough to produce RGB extra-mixing, two-dimensional numerical simulations of thermohaline convection for physical conditions corresponding to the RGB case have been carried out. We have found that the effective ratio of a salt finger's length to its diameter a{sub eff} {approx}< 0.5 is more than 10 times smaller than the value needed to reproduce observations (a{sub obs} {approx}> 7). On the other hand,more » using the thermohaline diffusion coefficient from linear stability analysis together with a = a{sub obs} is able to describe the RGB extra-mixing at all metallicities so well that it is tempting to believe that it may represent the true mechanism. In view of these results, follow-up three-dimensional numerical simulations of thermohaline convection for the RGB case are clearly needed.« less

  16. A neural network based implementation of an MPC algorithm applied in the control systems of electromechanical plants

    NASA Astrophysics Data System (ADS)

    Marusak, Piotr M.; Kuntanapreeda, Suwat

    2018-01-01

    The paper considers application of a neural network based implementation of a model predictive control (MPC) control algorithm to electromechanical plants. Properties of such control plants implicate that a relatively short sampling time should be used. However, in such a case, finding the control value numerically may be too time-consuming. Therefore, the current paper tests the solution based on transforming the MPC optimization problem into a set of differential equations whose solution is the same as that of the original optimization problem. This set of differential equations can be interpreted as a dynamic neural network. In such an approach, the constraints can be introduced into the optimization problem with relative ease. Moreover, the solution of the optimization problem can be obtained faster than when the standard numerical quadratic programming routine is used. However, a very careful tuning of the algorithm is needed to achieve this. A DC motor and an electrohydraulic actuator are taken as illustrative examples. The feasibility and effectiveness of the proposed approach are demonstrated through numerical simulations.

  17. Collectivity, Distributivity, and the Interpretation of Plural Numerical Expressions in Child and Adult Language

    PubMed Central

    Musolino, Julien

    2013-01-01

    Sentences containing plural numerical expressions (e.g., two boys) can give rise to two interpretations (collective and distributive), arising from the fact that their representation admits of a part-whole structure. We present the results of a series of experiments designed to explore children’s understanding of this distinction and its implications for the acquisition of linguistic expressions with number words. We show that preschoolers access both interpretations, indicating that they have the requisite linguistic and conceptual machinery to generate the corresponding representations. Furthermore, they can shift their interpretation in response to structural and lexical manipulations. However, they are not fully adult-like: unlike adults, they are drawn to the distributive interpretation, and are not yet aware of the lexical semantics of each and together, which should favor one or another interpretation. This research bridges a gap between a well-established body of work in cognitive psychology on the acquisition of number words and more recent work investigating children’s knowledge of the syntactic and semantic properties of sentences featuring numerical expressions. PMID:24223477

  18. The Cognitive Advantages of Counting Specifically: A Representational Analysis of Verbal Numeration Systems in Oceanic Languages.

    PubMed

    Bender, Andrea; Schlimm, Dirk; Beller, Sieghard

    2015-10-01

    The domain of numbers provides a paradigmatic case for investigating interactions of culture, language, and cognition: Numerical competencies are considered a core domain of knowledge, and yet the development of specifically human abilities presupposes cultural and linguistic input by way of counting sequences. These sequences constitute systems with distinct structural properties, the cross-linguistic variability of which has implications for number representation and processing. Such representational effects are scrutinized for two types of verbal numeration systems-general and object-specific ones-that were in parallel use in several Oceanic languages (English with its general system is included for comparison). The analysis indicates that the object-specific systems outperform the general systems with respect to counting and mental arithmetic, largely due to their regular and more compact representation. What these findings reveal on cognitive diversity, how the conjectures involved speak to more general issues in cognitive science, and how the approach taken here might help to bridge the gap between anthropology and other cognitive sciences is discussed in the conclusion. Copyright © 2015 Cognitive Science Society, Inc.

  19. Risk assessment of storm surge disaster based on numerical models and remote sensing

    NASA Astrophysics Data System (ADS)

    Liu, Qingrong; Ruan, Chengqing; Zhong, Shan; Li, Jian; Yin, Zhonghui; Lian, Xihu

    2018-06-01

    Storm surge is one of the most serious ocean disasters in the world. Risk assessment of storm surge disaster for coastal areas has important implications for planning economic development and reducing disaster losses. Based on risk assessment theory, this paper uses coastal hydrological observations, a numerical storm surge model and multi-source remote sensing data, proposes methods for valuing hazard and vulnerability for storm surge and builds a storm surge risk assessment model. Storm surges in different recurrence periods are simulated in numerical models and the flooding areas and depth are calculated, which are used for assessing the hazard of storm surge; remote sensing data and GIS technology are used for extraction of coastal key objects and classification of coastal land use are identified, which is used for vulnerability assessment of storm surge disaster. The storm surge risk assessment model is applied for a typical coastal city, and the result shows the reliability and validity of the risk assessment model. The building and application of storm surge risk assessment model provides some basis reference for the city development plan and strengthens disaster prevention and mitigation.

  20. Collectivity, Distributivity, and the Interpretation of Plural Numerical Expressions in Child and Adult Language.

    PubMed

    Syrett, Kristen; Musolino, Julien

    2013-01-01

    Sentences containing plural numerical expressions (e.g., two boys ) can give rise to two interpretations (collective and distributive), arising from the fact that their representation admits of a part-whole structure. We present the results of a series of experiments designed to explore children's understanding of this distinction and its implications for the acquisition of linguistic expressions with number words. We show that preschoolers access both interpretations, indicating that they have the requisite linguistic and conceptual machinery to generate the corresponding representations. Furthermore, they can shift their interpretation in response to structural and lexical manipulations. However, they are not fully adult-like: unlike adults, they are drawn to the distributive interpretation, and are not yet aware of the lexical semantics of each and together , which should favor one or another interpretation. This research bridges a gap between a well-established body of work in cognitive psychology on the acquisition of number words and more recent work investigating children's knowledge of the syntactic and semantic properties of sentences featuring numerical expressions.

  1. Dark matter substructure in numerical simulations: a tale of discreteness noise, runaway instabilities, and artificial disruption

    NASA Astrophysics Data System (ADS)

    van den Bosch, Frank C.; Ogiya, Go

    2018-04-01

    To gain understanding of the complicated, non-linear, and numerical processes associated with the tidal evolution of dark matter subhaloes in numerical simulation, we perform a large suite of idealized simulations that follow individual N-body subhaloes in a fixed, analytical host halo potential. By varying both physical and numerical parameters, we investigate under what conditions the subhaloes undergo disruption. We confirm the conclusions from our more analytical assessment in van den Bosch et al. that most disruption is numerical in origin; as long as a subhalo is resolved with sufficient mass and force resolution, a bound remnant survives. This implies that state-of-the-art cosmological simulations still suffer from significant overmerging. We demonstrate that this is mainly due to inadequate force softening, which causes excessive mass loss and artificial tidal disruption. In addition, we show that subhaloes in N-body simulations are susceptible to a runaway instability triggered by the amplification of discreteness noise in the presence of a tidal field. These two processes conspire to put serious limitations on the reliability of dark matter substructure in state-of-the-art cosmological simulations. We present two criteria that can be used to assess whether individual subhaloes in cosmological simulations are reliable or not, and advocate that subhaloes that satisfy either of these two criteria be discarded from further analysis. We discuss the potential implications of this work for several areas in astrophysics.

  2. Public Health Implications of the 1540 nm Laser on the Cornea

    DTIC Science & Technology

    2007-05-30

    film layer. The epithelium has numerous nerve endings that make the cornea extremely sensitive to pain when an injury occurs. This pain reflex helps...used in research by using techniques and procedures that reduce distress and pain The Three R’s have lead researchers to look for alternative models...cause severe pain and render a person incapable of working. Injury to the cornea may cause temporary to permanent vision impairment depending on how

  3. The History and Implications of Design Standards for Underwater Breathing Apparatus - 1954 to 2015

    DTIC Science & Technology

    2015-02-11

    respiratory loading using both simple models of fluid mechanics and experimental evidence. An understanding of the influence of both respiratory ventilatory... fluid dynamics of flow in divers’ airways. It allows testing laboratories to make maximum use of all of their testing data, and lo present that data in...tireless efforts of numerous military divers at Navy Experimental Diving Unit in Panama City, FL and Naval Medical Research Institute, Bethesda, MD

  4. Overview of Iron Metabolism in Health and Disease

    PubMed Central

    Dev, Som; Babitt, Jodie L.

    2017-01-01

    Iron is an essential element for numerous fundamental biologic processes, but excess iron is toxic. Abnormalities in systemic iron balance are common in patients with chronic kidney disease (CKD) and iron administration is a mainstay of anemia management in many patients. This review provides an overview of the essential role of iron in biology, the regulation of systemic and cellular iron homeostasis, how imbalances in iron homeostasis contribute to disease, and the implications for CKD patients. PMID:28296010

  5. An optimal consumption and investment problem with quadratic utility and negative wealth constraints.

    PubMed

    Roh, Kum-Hwan; Kim, Ji Yeoun; Shin, Yong Hyun

    2017-01-01

    In this paper, we investigate the optimal consumption and portfolio selection problem with negative wealth constraints for an economic agent who has a quadratic utility function of consumption and receives a constant labor income. Due to the property of the quadratic utility function, we separate our problem into two cases and derive the closed-form solutions for each case. We also illustrate some numerical implications of the optimal consumption and portfolio.

  6. Dyakonov-Shur instability across the ballistic-to-hydrodynamic crossover

    NASA Astrophysics Data System (ADS)

    Mendl, Christian B.; Lucas, Andrew

    2018-03-01

    We numerically solve semiclassical kinetic equations and compute the growth rate of the Dyakonov-Shur instability of a two-dimensional Fermi liquid in a finite length cavity. When electron-electron scattering is fast, we observe the well-understood hydrodynamic instability and its disappearance due to viscous dissipation. When electron-electron scattering is negligible, we find that the instability re-emerges for certain boundary conditions but not for others. We discuss the implications of these findings for experiments.

  7. Dyakonov-Shur instability across the ballistic-to-hydrodynamic crossover

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mendl, Christian B.; Lucas, Andrew

    Here, we numerically solve semiclassical kinetic equations and compute the growth rate of the Dyakonov-Shur instability of a two-dimensional Fermi liquid in a finite length cavity. When electron-electron scattering is fast, we observe the well-understood hydrodynamic instability and its disappearance due to viscous dissipation. When electron-electron scattering is negligible, we find that the instability re-emerges for certain boundary conditions but not for others. We discuss the implications of these findings for experiments.

  8. Dyakonov-Shur instability across the ballistic-to-hydrodynamic crossover

    DOE PAGES

    Mendl, Christian B.; Lucas, Andrew

    2018-03-19

    Here, we numerically solve semiclassical kinetic equations and compute the growth rate of the Dyakonov-Shur instability of a two-dimensional Fermi liquid in a finite length cavity. When electron-electron scattering is fast, we observe the well-understood hydrodynamic instability and its disappearance due to viscous dissipation. When electron-electron scattering is negligible, we find that the instability re-emerges for certain boundary conditions but not for others. We discuss the implications of these findings for experiments.

  9. To admit or not to admit? The effect of framing on risk assessment decision making in psychiatrists.

    PubMed

    Jefferies-Sewell, Kiri; Sharma, Shivani; Gale, Tim M; Hawley, Chris J; Georgiou, George J; Laws, Keith R

    2015-02-01

    The way that information is presented is well known to induce a range of biases in human decision tasks. Little research exists on framing effects in psychiatric decision making, but it is reasonable to assume that psychiatrists are not immune and, if so, there may be implications for the welfare of patients, staff and the general public. To investigate whether presentation of risk information in different formats (frequency, percentage and semantic) influences inpatient admission decisions by psychiatrists. Six-hundred seventy-eight general adult psychiatrists read a short clinical vignette presenting a case scenario of a patient presenting for inpatient admission. One of four condition questions followed the vignette, incorporating either numerical or percentage probabilities and the semantic labels "high" and "low" risk. In each condition, the actual risk was identical, but the way it was presented varied. The decision to admit the patient or not was recorded and compared across conditions. More individuals chose to admit the patient when risk information was presented in numerical form (X2 = 7.43, p = 0.006) and with the semantic label "high" (X2 = 7.27, p = 0.007). Presentation of risk information may influence decision making in psychiatrists. This has important implications for mental health clinical practice where clinicians are required to interpret probabilistic information within their daily work.

  10. False memories with age: neural and cognitive underpinnings

    PubMed Central

    Devitt, Aleea L.; Schacter, Daniel L.

    2016-01-01

    As we age we become increasingly susceptible to memory distortions and inaccuracies. Over the past decade numerous neuroimaging studies have attempted to illuminate the neural underpinnings of aging and false memory. Here we review these studies, and link their findings with those concerning the cognitive properties of age-related changes in memory accuracy. Collectively this evidence points towards a prominent role for age-related declines in medial temporal and prefrontal brain areas, and corresponding impairments in associative binding and strategic monitoring. A resulting cascade of cognitive changes contributes to the heightened vulnerability to false memories with age, including reduced recollective ability, a reliance on gist information and familiarity-based monitoring mechanisms, as well as a reduced ability to inhibit irrelevant information and erroneous binding of features between memory traces. We consider both theoretical and applied implications of research on aging and false memories, as well as questions remaining to be addressed in future research. PMID:27592332

  11. Mapping multivalency and differential affinities within large intrinsically disordered protein complexes with segmental motion analysis.

    PubMed

    Milles, Sigrid; Lemke, Edward A

    2014-07-07

    Intrinsically disordered proteins (IDPs) can bind to multiple interaction partners. Numerous binding regions in the IDP that act in concert through complex cooperative effects facilitate such interactions, but complicate studying IDP complexes. To address this challenge we developed a combined fluorescence correlation and time-resolved polarization spectroscopy approach to study the binding properties of the IDP nucleoporin153 (Nup153) to nuclear transport receptors (NTRs). The detection of segmental backbone mobility of Nup153 within the unperturbed complex provided a readout of local, region-specific binding properties that are usually masked in measurements of the whole IDP. The binding affinities of functionally and structurally diverse NTRs to distinct regions of Nup153 can differ by orders of magnitudes-a result with implications for the diversity of transport routes in nucleocytoplasmic transport. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Space-based Remote Sensing: A Tool for Studying Bird Migration Across Multiple Scales

    NASA Technical Reports Server (NTRS)

    Smith, James A.

    2005-01-01

    The study of bird migration on a global scale is one of the compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties. Space based technology offers new opportunities to shed understanding on the distribution and migration of organisms on the planet and their sensitivity to human disturbances and environmental changes. Our working hypothesis is that individual organism biophysical models of energy and water balance, driven by satellite measurements of spatio-temporal gradients in climate and habitat, will help us to explain the variability in avian species richness and distribution. Further, these models provide an ecological forecasting tool for science and application users to visualize the possible consequences of loss of wetlands, flooding, or other natural disasters such as hurricanes on avian biodiversity and bird migration.

  13. Intelligent agents for adaptive security market surveillance

    NASA Astrophysics Data System (ADS)

    Chen, Kun; Li, Xin; Xu, Baoxun; Yan, Jiaqi; Wang, Huaiqing

    2017-05-01

    Market surveillance systems have increasingly gained in usage for monitoring trading activities in stock markets to maintain market integrity. Existing systems primarily focus on the numerical analysis of market activity data and generally ignore textual information. To fulfil the requirements of information-based surveillance, a multi-agent-based architecture that uses agent intercommunication and incremental learning mechanisms is proposed to provide a flexible and adaptive inspection process. A prototype system is implemented using the techniques of text mining and rule-based reasoning, among others. Based on experiments in the scalping surveillance scenario, the system can identify target information evidence up to 87.50% of the time and automatically identify 70.59% of cases depending on the constraints on the available information sources. The results of this study indicate that the proposed information surveillance system is effective. This study thus contributes to the market surveillance literature and has significant practical implications.

  14. Parents’ Management of Children’s Pain at Home after Surgery

    PubMed Central

    Vincent, Catherine; Chiappetta, Maria; Beach, Abigail; Kiolbasa, Carolyn; Latta, Kelsey; Maloney, Rebekah; Van Roeyen, Linda Sue

    2012-01-01

    Purpose We tested Home Pain Management for Children (HPMC) for effects on pain intensity, analgesics administered, satisfaction, and use of healthcare services over 3 post-discharge days. Design and Methods In this quasi-experimental study with 108 children and their parents, we used the numeric rating scale (NRS) or the Faces Pain Scale-Revised (FPS-R), calculated percentages of analgesics administered, and asked questions about expectations, satisfaction, and services. Between-group differences were tested with t-tests and ANOVA. Results After HPMC, children reported moderate pain and parents administered more analgesics on 2 study days. Parents and children were satisfied; parents used few services. Written instructions and a brief interactive session were not sufficient to change parents’ analgesic administration practices to relieve their children’s pain. Practice Implications Further research is needed to develop and test effective education interventions to facilitate relief of children’s post-operative pain. PMID:22463471

  15. On the the Contact Lens Problem: Modeling Rigid and Elastic Beams on Thin Films

    NASA Astrophysics Data System (ADS)

    Trinh, Philippe; Wilson, Stephen; Stone, Howard

    2011-11-01

    Generally, contact lenses are prescribed by the practitioner to fit each individual patient's eye, but these fitting-philosophies are based on empirical studies and a certain degree of trial-and-error. A badly fitted lens can cause a range of afflictions, which varies from mild dry-eye-discomfort, to more serious corneal diseases. Thus, at this heart of this problem, is the question of how a rigid or elastic plate interacts with the free-surface of a thin viscous film. In this talk, we present several mathematical models for the study of these plate-and-fluid problems. Asymptotic and numerical results are described, and we explain the role of elasticity, surface tension, viscosity, and pressure in determining the equilibrium solutions. Finally, we discuss the implications of our work on the contact lens problem, as well as on other coating processes which involve elastic substrates.

  16. Mechanically Activated Ion Channels

    PubMed Central

    Ranade, Sanjeev S.; Syeda, Ruhma; Patapoutian, Ardem

    2015-01-01

    Mechanotransduction, the conversion of physical forces into biochemical signals, is an essential component of numerous physiological processes including not only conscious senses of touch and hearing, but also unconscious senses such as blood pressure regulation. Mechanically activated (MA) ion channels have been proposed as sensors of physical force, but the identity of these channels and an understanding of how mechanical force is transduced has remained elusive. A number of recent studies on previously known ion channels along with the identification of novel MA ion channels have greatly transformed our understanding of touch and hearing in both vertebrates and invertebrates. Here, we present an updated review of eukaryotic ion channel families that have been implicated in mechanotransduction processes and evaluate the qualifications of the candidate genes according to specified criteria. We then discuss the proposed gating models for MA ion channels and highlight recent structural studies of mechanosensitive potassium channels. PMID:26402601

  17. Emerging Common Molecular Pathways for Primary Dystonia

    PubMed Central

    LeDoux, Mark S; Dauer, William T; Warner, Thomas T

    2013-01-01

    Background The dystonias are a group of hyperkinetic movement disorders whose principal cause is neuron dysfunction at one or more interconnected nodes of the motor system. The study of genes and proteins which cause familial dystonia provides critical information about the cellular pathways involved in this dysfunction which disrupts the motor pathways at systems level. In recent years study of the increasing number of DYT genes has implicated a number of cell functions which appear to be involved in the pathogenesis of dystonia. Methods Review of literature published in English language publications available on Pubmed relating to the genetics and cellular pathology of dystonia Results and Conclusions Numerous potential pathogenetic mechanisms have been identified. We describe those which fall into three emerging thematic groups: cell cycle and transcriptional regulation in the nucleus, endoplasmic reticulum and nuclear envelope function, and control of synaptic function. PMID:23893453

  18. Growing Up Amid Ethno-Political Conflict: Aggression and Emotional Desensitization Promote Hostility to Ethnic Outgroups.

    PubMed

    Niwa, Erika Y; Boxer, Paul; Dubow, Eric; Huesmann, L R; Shikaki, Khalil; Landau, Simha; Gvirsman, Shira D

    2016-09-01

    Ethno-political violence impacts thousands of youth and is associated with numerous negative outcomes. Yet little research examines adaptation to ethno-political violence over time or across multiple outcomes simultaneously. This study examines longitudinal patterns of aggressive behavior and emotional distress as they co-occur among Palestinian (n = 600) youth exposed to ethno-political violence over 3 years in three age cohorts (starting ages: 8, 11, and 14). Findings indicate distinct profiles of aggressive behavior and emotional distress, and unique joint patterns. Furthermore, youth among key joint profiles (e.g., high aggression-emotional desensitization) are more likely to endorse normative beliefs about aggression toward ethnic outgroups. This study offers a dynamic perspective on emotional and behavioral adaptation to ethno-political violence and the implications of those processes. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

  19. Experimental characterization of 3-dimensional gravity-driven fingering in a porous medium

    NASA Astrophysics Data System (ADS)

    Dalbe, Marie-Julie; Juanes, Ruben

    2017-11-01

    When water infiltrates a dry porous media, a gravity-driven instability can be observed. Water will penetrate the porous media along preferential paths, called fingers. This gravity-driven unstable multiphase flow has important implications for natural phenomena such as rainwater infiltration in soil and secondary oil migration in reservoir rocks. While several experimental and numerical studies have described the instability in 2-dimensional (2D) settings, fundamental questions remain on the morphodynamics of gravity fingering in 3D. We developed a 3D experimental set-up based on planar laser-induced fluorescence of index-matched fluids that allows us to image this phenomenon dynamically. We study the impact of some crucial parameters such as rainfall rate or grain size on the finger size and velocity. In addition, experiments in stratified media reveal interesting dynamics of finger flow across material interfaces, an essential aspect towards the understanding of water infiltration in soils.

  20. Modeling initiation trains based on HMX and TATB

    NASA Astrophysics Data System (ADS)

    Drake, R. C.; Maisey, M.

    2017-01-01

    There will always be a requirement to reduce the size of initiation trains. However, as the size is reduced the performance characteristics can be compromised. A detailed science-based understanding of the processes (ignition and growth to detonation) which determine the performance characteristics is required to enable compact and robust initiation trains to be designed. To assess the use of numerical models in the design of initiation trains a modeling study has been undertaken, with the aim of understanding the initiation of TATB and HMX charges by a confined, surface mounted detonator. The effect of detonator diameter and detonator confinement on the formation of dead zones in the acceptor explosives has been studied. The size of dead zones can be reduced by increasing the diameter of the detonator and by increasing the impedance of the confinement. The implications for the design of initiation trains are discussed.

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