Science.gov

Sample records for affect structural performance

  1. Does Question Structure Affect Exam Performance in the Geosciences?

    NASA Astrophysics Data System (ADS)

    Day, E. A.; D'Arcy, M. K.; Craig, L.; Streule, M. J.; Passmore, E.; Irving, J. C. E.

    2015-12-01

    The jump to university level exams can be challenging for some students, often resulting in poor marks, which may be detrimental to their confidence and ultimately affect their overall degree class. Previous studies have found that question structure can have a strong impact on the performance of students in college level exams (see Gibson et al., 2015, for a discussion of its impact on physics undergraduates). Here, we investigate the effect of question structure on the exam results of geology and geophysics undergraduate students. Specifically, we analyse the performance of students in questions that have a 'scaffolded' framework and compare them to their performance in open-ended questions and coursework. We also investigate if observed differences in exam performance are correlated with the educational background and gender of students, amongst other factors. It is important for all students to be able to access their degree courses, no matter what their backgrounds may be. Broadening participation in the geosciences relies on removing systematic barriers to achievement. Therefore we recommend that exams are either structured with scaffolding in questions at lower levels, or students are explicitly prepared for this transition. We also recommend that longitudinal studies of exam performance are conducted within individual departments, and this work outlines one approach to analysing performance data.

  2. How Motivation Affects Academic Performance: A Structural Equation Modelling Analysis

    ERIC Educational Resources Information Center

    Kusurkar, R. A.; Ten Cate, Th. J.; Vos, C. M. P.; Westers, P.; Croiset, G.

    2013-01-01

    Few studies in medical education have studied effect of quality of motivation on performance. Self-Determination Theory based on quality of motivation differentiates between Autonomous Motivation (AM) that originates within an individual and Controlled Motivation (CM) that originates from external sources. To determine whether Relative Autonomous…

  3. The Consequences of Perfectionism Scale: Factorial Structure and Relationships with Perfectionism, Performance Perfectionism, Affect, and Depressive Symptoms

    ERIC Educational Resources Information Center

    Stoeber, Joachim; Hoyle, Azina; Last, Freyja

    2013-01-01

    This study investigated the Consequences of Perfectionism Scale (COPS) and its relationships with perfectionism, performance perfectionism, affect, and depressive symptoms in 202 university students using confirmatory factor analysis, correlations, and regression analyses. Results suggest that the COPS is a reliable and valid measure of positive…

  4. Quantum Tunneling Affects Engine Performance.

    PubMed

    Som, Sibendu; Liu, Wei; Zhou, Dingyu D Y; Magnotti, Gina M; Sivaramakrishnan, Raghu; Longman, Douglas E; Skodje, Rex T; Davis, Michael J

    2013-06-20

    We study the role of individual reaction rates on engine performance, with an emphasis on the contribution of quantum tunneling. It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. The three-dimensional model includes detailed descriptions of the chemistry of a surrogate for a biodiesel fuel, as well as all the features of the engine, such as the liquid fuel spray and turbulence. This study is part of a larger investigation of how the features of the dynamics and potential energy surfaces of key reactions, as well as their reaction rate uncertainties, affect engine performance, and results in these directions are also presented here. PMID:26283246

  5. Individual difference variables, affective differentiation, and the structures of affect.

    PubMed

    Terracciano, Antonio; McCrae, Robert R; Hagemann, Dirk; Costa, Paul T

    2003-10-01

    Methodological arguments are usually invoked to explain variations in the structure of affect. Using self-rated affect from Italian samples (N=600), we show that individual difference variables related to affective differentiation can moderate the observed structure. Indices of circumplexity and congruence coefficients to the hypothesized target were used to quantify the observed structures. Results did not support the circumplex model as a universal structure. A circular structure with axes of activation and valence was approximated only among more affectively differentiated groups: students and respondents with high scores on Openness to Feelings and measures of negative emotionality. A different structure, with unipolar Positive Affect and Negative Affect factors, was observed among adults and respondents with low Openness to Feelings and negative emotionality. The observed structure of affect will depend in part on the nature of the sample studied. PMID:12932207

  6. Individual Difference Variables, Affective Differentiation, and the Structures of Affect

    PubMed Central

    Terracciano, Antonio; McCrae, Robert R.; Hagemann, Dirk; Costa, Paul T.

    2008-01-01

    Methodological arguments are usually invoked to explain variations in the structure of affect. Using self-rated affect from Italian samples (N = 600), we show that individual difference variables related to affective differentiation can moderate the observed structure. Indices of circumplexity (Browne, 1992) and congruence coefficients to the hypothesized target were used to quantify the observed structures. Results did not support the circumplex model as a universal structure. A circular structure with axes of activation and valence was approximated only among more affectively differentiated groups: students and respondents with high scores on Openness to Feelings and measures of negative emotionality. A different structure, with unipolar Positive Affect and Negative Affect factors, was observed among adults and respondents with low Openness to Feelings and negative emotionality. The observed structure of affect will depend in part on the nature of the sample studied. PMID:12932207

  7. Deviant white matter structure in adults with attention-deficit/hyperactivity disorder points to aberrant myelination and affects neuropsychological performance.

    PubMed

    Onnink, A Marten H; Zwiers, Marcel P; Hoogman, Martine; Mostert, Jeanette C; Dammers, Janneke; Kan, Cornelis C; Vasquez, Alejandro Arias; Schene, Aart H; Buitelaar, Jan; Franke, Barbara

    2015-12-01

    Attention-deficit/hyperactivity disorder (ADHD) in childhood is characterized by gray and white matter abnormalities in several brain areas. Considerably less is known about white matter microstructure in adults with ADHD and its relation with clinical symptoms and cognitive performance. In 107 adult ADHD patients and 109 gender-, age- and IQ-matched controls, we used diffusion tensor imaging (DTI) with tract-based spatial statistics (TBSS) to investigate whole-skeleton changes of fractional anisotropy (FA) and mean, axial, and radial diffusivity (MD, AD, RD). Additionally, we studied the relation of FA and MD values with symptom severity and cognitive performance on tasks measuring working memory, attention, inhibition, and delay discounting. In comparison to controls, participants with ADHD showed reduced FA in corpus callosum, bilateral corona radiata, and thalamic radiation. Higher MD and RD were found in overlapping and even more widespread areas in both hemispheres, also encompassing internal and external capsule, sagittal stratum, fornix, and superior lateral fasciculus. Values of FA and MD were not associated with symptom severity. However, within some white matter clusters that distinguished patients from controls, worse inhibition performance was associated with reduced FA and more impulsive decision making was associated with increased MD. This study shows widespread differences in white matter integrity between adults with persistent ADHD and healthy individuals. Changes in RD suggest aberrant myelination as a pathophysiological factor in persistent ADHD. The microstructural differences in adult ADHD may contribute to poor inhibition and greater impulsivity but appear to be independent of disease severity. PMID:25956761

  8. How Coriolis meter design affects field performance

    SciTech Connect

    Levien, A.; Dudiak, A.

    1995-12-31

    Although many possibilities exist for the design of Coriolis flowmeters, a common set of fundamental physical principles affect practical meter design. Design criteria such as tube geometry, alloy section, operating frequencies, stress levels, and tubing wall thickness have varying impacts on meter performance. Additionally, field conditions such as changing temperature, pressure, pipeline stress and vibration affect measurement performance. The challenge created in Coriolis flow meter design is to maximize the sensitivity of the meter Coriolis forces, while minimizing the impact of outside environmental influences. Data are presented on the physical principles that affect Coriolis flowmeters, and how the various aspects of meter design influence field performance.

  9. A Structural Equation Model of the Effects of Negative Affectivity, Leader-Member Exchange, and Perceived Job Mobility on In-role and Extra-role Performance: A Chinese Case.

    PubMed

    Hui; Law; Chen

    1999-01-01

    In this paper, we contrast the effects of leader-member exchange (LMX) with the effects of perceived job mobility on in-role performance and organizational citizenship behavior (OCB). We further model negative affectivity as the antecedent of both LMX and perceived job mobility and suggest that LMX and perceived job mobility mediated the relationship between negative affectivity and performance. We obtained matching data from supervisor and subordinates in a major battery manufacturing company in southern China. Subordinates provided the negative affectivity, perceived job mobility, and LMX assessment, and their immediate supervisors provided the in-role performance and OCB assessment. Results from a structural equation analysis show that both LMX and perceived job mobility predicted OCB. Instead of being a direct antecedent of OCB, the relationship between negative affectivity and OCB is found to be mediated by LMX and perceived job mobility. Theoretical implications of the results are discussed. Copyright 1999 Academic Press. PMID:9924139

  10. Factors affecting performance of dispenser photocathodes

    NASA Astrophysics Data System (ADS)

    Moody, Nathan A.; Jensen, Kevin L.; Feldman, Donald W.; Montgomery, Eric J.; O'Shea, Patrick G.

    2007-11-01

    Usable lifetime has long been a limitation of high efficiency photocathodes in high average current accelerator applications such as free electron lasers, where poor vacuum conditions and high incident laser power contribute to early degradation in electron beam emission. Recent progress has been made in adapting well known thermionic dispenser techniques to photocathodes, resulting in a dispenser photocathode whose photosensitive surface coating of cesium can be periodically replenished to extend effective lifetime. This article details the design and fabrication process of a prototype cesium dispenser photocathode and describes in detail the dominant factors affecting its performance: activation procedure, surface cleanliness, temperature, and substrate microstructure.

  11. Determining structural performance

    NASA Technical Reports Server (NTRS)

    Ernst, Michael A.; Kiraly, Louis J.

    1987-01-01

    An overview is given of the methods and concepts developed to enhance and predict structural dynamic characteristics of advanced aeropropulsion systems. Aeroelasticity, Vibration Control, Dynamic Systems, and Computational Structural Methods are four disciplines that make up the research program at NASA/Lewis Research Center. The Aeroelasticity program develops analytical and experimental methods to minimize flutter and forced vibration of aerospace propulsion systems. Both frequency domain and time domain methods have been developed for applications on the turbofan, turbopump, and advanced turboprop. To improve life and performance, the Vibration Control program conceives, analyzes, develops, and demonstrates new methods to control vibrations in aerospace systems. Active and passive vibration control is accomplished with electromagnetic dampers, magnetic bearings, and piezoelectric crystals to control rotor vibrations. The Dynamic Systems program analyzes and verifies the dynamics of interacting systems, as well as develops concepts and methods for high-temperature dynamic seals. The Computational Structural Methods program uses computer science to improve solutions of structural problems.

  12. Determining structural performance

    NASA Technical Reports Server (NTRS)

    Ernst, Michael A. (Editor); Brown, Gerald; Dirusso, Eliseo; Fleming, David; Janetzke, David; Kascak, Albert; Kaza, Krishna; Kielb, Robert; Kiraly, Louis J.; Lawrence, Charles

    1990-01-01

    An overview of the methods and concepts developed to enhance and predict structural dynamic characteristics of advanced aeropropulsion systems is presented. Aeroelasticity, vibration control, dynamic systems, and computational structural methods are four disciplines that make up the structural dynamic effort at LeRC. The aeroelasticity program develops analytical and experimental methods for minimizing flutter and forced vibration of aerospace propulsion systems. Both frequency domain and time domain methods were developed for applications on the turbofan, turbopump, and advanced turboprop. In order to improve life and performance, the vibration control program conceives, analyzes, develops, and demonstrates new methods for controlling vibrations in aerospace systems. Active and passive vibration control is accomplished with electromagnetic dampers, magnetic bearings, and piezoelectric crystals to control rotor vibrations. The dynamic systems program analyzes and verifies the dynamics of interacting systems, as well as develops concepts and methods for high-temperature dynamic seals. Work in this field involves the analysis and parametric identification of large, nonlinear, damped, stochastic systems. The computational structural methods program exploits modern computer science as an aid to the solutions of structural problems.

  13. Does Motivation Affect Performance via Persistence?

    ERIC Educational Resources Information Center

    Vollmeyer, Regina; Rheinberg, Falko

    2000-01-01

    Studied the relationships among motivation, persistence, and performance in a sample of 51 German college students. Path analysis showed that initial motivation influenced persistence but that the relationship between persistence and performance was disrupted because learners with more knowledge stopped sooner. (SLD)

  14. Factors Affecting Performance of Soil Termiticides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Applying liquid insecticide to soil under and around structures is one of the most widely used methods of subterranean termite prevention and control. Failure of soil termiticide treatments is often related to factors other than the active ingredient. Efficacy and longevity of soil treatments vary g...

  15. Student Profiles and Factors Affecting Performance.

    ERIC Educational Resources Information Center

    Chansarkar, B. A.; Michaeloudis, A.

    2001-01-01

    Studies the profiling of first year students studying the Quantitative Methods for Business module at a British university, and makes policy recommendations to improve student performance. Indicates that the highest proportion of students are United Kingdom students, 58% of the students are male, and only 30% of the students are mature students.…

  16. Factors affecting performance of engineered barriers

    SciTech Connect

    Blink, J. A., LLNL

    1998-03-01

    For the Yucca Mountain Viability Assessment (VA), a reference design was tentatively selected` In September 1997, and a series of model abstractions are being prepared for the performance assessment (PA) of that design. To determine the sensitivity of peak dose rate at the accessible environment to engineered components, several design options were subjected to the PA models available late in FY97.

  17. FACTORS AFFECTING PERFORMANCE OF ENGINEERED BARRIERS

    SciTech Connect

    Blink, J. A.; Bailey, T. W.; Doering, W.; Lee, J. K.; Mccoy, J. K.; McKenzie, D. G.; Sevougian, D.; Vallikat, V.

    1998-03-01

    For the Yucca Mountain Viability Assessment (VA), a reference design was tentatively selected in September 1997, and a series of model abstractions are being prepared for the performance assessment (PA) of that design. To determine the sensitivity of peak dose rate at the accessible environment to engineered components, several design options were subjected to the PA models available late in FY97.

  18. Hyperinsulinemia adversely affects lung structure and function.

    PubMed

    Singh, Suchita; Bodas, Manish; Bhatraju, Naveen K; Pattnaik, Bijay; Gheware, Atish; Parameswaran, Praveen Kolumam; Thompson, Michael; Freeman, Michelle; Mabalirajan, Ulaganathan; Gosens, Reinoud; Ghosh, Balaram; Pabelick, Christina; Linneberg, Allan; Prakash, Y S; Agrawal, Anurag

    2016-05-01

    There is limited knowledge regarding the consequences of hyperinsulinemia on the lung. Given the increasing prevalence of obesity, insulin resistance, and epidemiological associations with asthma, this is a critical lacuna, more so with inhaled insulin on the horizon. Here, we demonstrate that insulin can adversely affect respiratory health. Insulin treatment (1 μg/ml) significantly (P < 0.05) increased the proliferation of primary human airway smooth muscle (ASM) cells and induced collagen release. Additionally, ASM cells showed a significant increase in calcium response and mitochondrial respiration upon insulin exposure. Mice administered intranasal insulin showed increased collagen deposition in the lungs as well as a significant increase in airway hyperresponsiveness. PI3K/Akt mediated activation of β-catenin, a positive regulator of epithelial-mesenchymal transition and fibrosis, was observed in the lungs of insulin-treated mice and lung cells. Our data suggests that hyperinsulinemia may have adverse effects on airway structure and function. Insulin-induced activation of β-catenin in lung tissue and the contractile effects on ASM cells may be causally related to the development of asthma-like phenotype. PMID:26919895

  19. Performance processes within affect-related performance zones: a multi-modal investigation of golf performance.

    PubMed

    van der Lei, Harry; Tenenbaum, Gershon

    2012-12-01

    Individual affect-related performance zones (IAPZs) method utilizing Kamata et al. (J Sport Exerc Psychol 24:189-208, 2002) probabilistic model of determining the individual zone of optimal functioning was utilized as idiosyncratic affective patterns during golf performance. To do so, three male golfers of a varsity golf team were observed during three rounds of golf competition. The investigation implemented a multi-modal assessment approach in which the probabilistic relationship between affective states and both, performance process and performance outcome, measures were determined. More specifically, introspective (i.e., verbal reports) and objective (heart rate and respiration rate) measures of arousal were incorporated to examine the relationships between arousal states and both, process components (i.e., routine consistency, timing), and outcome scores related to golf performance. Results revealed distinguishable and idiosyncratic IAPZs associated with physiological and introspective measures for each golfer. The associations between the IAPZs and decision-making or swing/stroke execution were strong and unique for each golfer. Results are elaborated using cognitive and affect-related concepts, and applications for practitioners are provided. PMID:22562463

  20. Lithium-oxygen batteries-Limiting factors that affect performance

    NASA Astrophysics Data System (ADS)

    Padbury, Richard; Zhang, Xiangwu

    2011-05-01

    Lithium-oxygen batteries have recently received attention due to their extremely high theoretical energy densities, which far exceed that of any other existing energy storage technology. The significantly larger theoretical energy density of the lithium-oxygen batteries is due to the use of a pure lithium metal anode and the fact that the cathode oxidant, oxygen, is stored externally since it can be readily obtained from the surrounding air. Before the lithium-oxygen batteries can be realized as high performance, commercially viable products, there are still many challenges to overcome, from designing their cathode structure, to optimizing their electrolyte compositions and elucidating the complex chemical reactions that occur during charge and discharge. The scientific obstacles that are related to the performance of the lithium-oxygen batteries open up an exciting opportunity for researchers from many different backgrounds to utilize their unique knowledge and skills to bridge the knowledge gaps that exist in current research projects. This article is a summary of the most significant limiting factors that affect the performance of the lithium-oxygen batteries from the perspective of the authors. The article indicates the relationships that form between various limiting factors and highlights the complex yet captivating nature of the research within this field.

  1. Mathematics Anxiety and the Affective Drop in Performance

    ERIC Educational Resources Information Center

    Ashcraft, Mark H.; Moore, Alex M.

    2009-01-01

    The authors provide a brief review of the history and assessment of math anxiety, its relationship to personal and educational consequences, and its important impact on measures of performance. Overall, math anxiety causes an "affective drop," a decline in performance when math is performed under timed, high-stakes conditions, both in laboratory…

  2. Perfectionism, Performance, and State Positive Affect and Negative Affect after a Classroom Test

    ERIC Educational Resources Information Center

    Flett, Gordon L.; Blankstein, Kirk R.; Hewitt, Paul L.

    2009-01-01

    The current study examined the associations among trait dimensions of perfectionism, test performance, and levels of positive and negative affect after taking a test. A sample of 92 female university students completed the Multidimensional Perfectionism Scale one week prior to an actual class test. Measures of positive affect and negative affect…

  3. Geotechnical Extreme Events Reconnaissance Report on the Performance of Structures in Densely Urbanized Areas Affected by Surface Fault Rupture During the August 24, 2014 M6 South Napa Earthquake, California, USA.

    NASA Astrophysics Data System (ADS)

    Cohen-Waeber, J.; Lanzafame, R.; Bray, J.; Sitar, N.

    2014-12-01

    The August 24, 2014, M­w 6.0 South Napa earthquake is the largest seismic event to have occurred in the San Francisco Bay Region, California, USA, since the Mw 6.9 1989 Loma Prieta earthquake. The event epicenter occurred at the South end of the Napa Valley, California, principally rupturing northwest along parts of the active West Napa fault zone. Bound by two major fault zones to the East and West (Calaveras and Rogers Creek, respectively), the Napa Valley is filled with up to 170 m. of alluvial deposits and is considered to be moderately to very highly susceptible to liquefaction and has the potential for violent shaking. While damage due to strong ground shaking was significant, remarkably little damage due to liquefaction or landslide induced ground deformations was observed. This may be due to recent drought in the region. Instead, the South Napa earthquake is the first to produce significant surface rupture in this area since the Mw 7.9 1906 San Andreas event, and the first in Northern California to rupture through a densely urbanized environment. Clear expressions of surface fault rupture extended approximately 12 - 15 km northward from the epicenter and approximately 1-2 km southeast with a significant impact to infrastructure, including roads, lifelines and residential structures. The National Science Foundation funded Geotechnical Extreme Events Reconnaissance (GEER) Association presents here its observations on the performance of structures affected by surface fault rupture, in a densely populated residential neighborhood located approximately 10 km north of the epicenter. Based on the detailed mapping of 27 residential structures, a preliminary assessment of the quantitative descriptions of damage shows certain characteristic interactions between surface fault rupture and the overlying infrastructure: 48% of concrete slabs cracked up to 8 cm wide, 19% of structures shifted up to 11 cm off of their foundation and 44% of foundations cracked up to 3 cm

  4. Factors Affecting Performance of Undergraduate Students in Construction Related Disciplines

    ERIC Educational Resources Information Center

    Olatunji, Samuel Olusola; Aghimien, Douglas Omoregie; Oke, Ayodeji Emmanuel; Olushola, Emmanuel

    2016-01-01

    Academic performance of students in Nigerian institutions has been of much concern to all and sundry hence the need to assess the factors affecting performance of undergraduate students in construction related discipline in Nigeria. A survey design was employed with questionnaires administered on students in the department of Quantity Surveying,…

  5. Focus of Attention Affects Performance of Motor Skills in Music

    ERIC Educational Resources Information Center

    Duke, Robert A.; Cash, Carla Davis; Allen, Sarah E.

    2011-01-01

    To test the extent to which learners performing a simple keyboard passage would be affected by directing their focus of attention to different aspects of their movements, 16 music majors performed a brief keyboard passage under each of four focus conditions arranged in a counterbalanced design--a total of 64 experimental sessions. As they…

  6. Protein crowding affects hydration structure and dynamics

    PubMed Central

    Harada, Ryuhei; Sugita, Yuji; Feig, Michael

    2012-01-01

    The effect of protein crowding on the structure and dynamics of water was examined from explicit solvent molecular dynamics simulations of a series of protein G and protein G/villin systems at different protein concentrations. Hydration structure was analyzed in terms of radial distribution functions, three-dimensional hydration sites, and preservation of tetrahedral coordination. Analysis of hydration dynamics focused on self-diffusion rates and dielectric constants as a function of crowding. The results show significant changes in both structure and dynamics of water under highly crowded conditions. The structure of water is altered mostly beyond the first solvation shell. Diffusion rates and dielectric constants are significantly reduced following linear trends as a function of crowding reflecting highly constrained water in crowded environments. The reduced dynamics of diffusion is expected to be strongly related to hydrodynamic properties of crowded cellular environments while the reduced dielectric constant under crowded conditions has implications for the stability of biomolecules in crowded environments. The results from this study suggest a prescription for modeling solvation in simulations of cellular environments. PMID:22352398

  7. Study of how sash movement affects performance of fume hoods

    SciTech Connect

    Hardwick, T.

    1997-12-31

    This study was conducted to determine how sash movements affect the performance of fume hoods. The performance of two fume hoods was studied as the sashes were moved from closed to open position at speeds of 2 ft/s, 1.5 ft/s, and 1 ft/s. The tests were conducted with fume hoods operated at both constant volume and variable air volume. The tests indicate that sash movements can disturb airflow patterns at the face of the hood and potentially affect the performance of the hood. The effect of the sash movement varied with hood type and speed of sash movement. The faster sash movements of 2 ft/s and 1.5 ft/s had a greater effect on the performance of the hoods than the slower movement of 1 ft/s. Constant-volume hoods and variable-air-volume hoods were both affected by sash movements. Constant-volume hoods set to a full open face velocity of 60 ft/min were more susceptible to the sash movement than at 100 ft/min full open face velocity. The performance of variable-air-volume hoods is affected not only by sash movement speed but also by the response time of the controller. The drop in face velocity that occurs when the sash is moved is determined by the speed of the VAV controller. The required response time for containment depends on the fume hood design and the speed of the sash movement.

  8. Recent Experience Affects the Strength of Structural Priming

    ERIC Educational Resources Information Center

    Kaschak, Michael P.; Loney, Renrick A.; Borreggine, Kristin L.

    2006-01-01

    In two experiments, we explore how recent experience with particular syntactic constructions affects the strength of the structural priming observed for those constructions. The results suggest that (1) the strength of structural priming observed for double object and prepositional object constructions is affected by the relative frequency with…

  9. Performance of fuselage pressure structure

    NASA Astrophysics Data System (ADS)

    Maclin, James R.

    1992-07-01

    There are currently more than 1,000 Boeing airplanes around the world over 20 years old. That number is expected to double by the year 1995. With these statistics comes the reality that structural airworthiness will be in the forefront of aviation issues well into the next century. The results of previous and recent test programs Boeing has implemented to study the structural performance of older airplanes relative to pressurized fuselage sections are described. Included in testing were flat panels with multiple site damage (MSD), a full-scale 737 and 2 747s as well as panels representing a 737 and 777, and a generic aircraft in large pressure-test fixtures. Because damage is a normal part of aging, focus is on the degree to which structural integrity is maintained after failure or partial failure of any structural element, including multiple site damage (MSD), and multiple element damage (MED).

  10. Economy Affects Students' Academic Performance as Well as Spending Decisions

    ERIC Educational Resources Information Center

    Sander, Libby

    2012-01-01

    Like many Americans caught up in the economic downturn, college students are worried about money. Now research indicates that financial worries may affect their academic performance. The author presents the results of this year's National Survey of Student Engagement. The survey reveals that more than a third of seniors and more than a quarter of…

  11. Cognitive, Affective, and Behavioral Determinants of Performance: A Process Model.

    ERIC Educational Resources Information Center

    Dorfman, Peter W.; Stephan, Walter G.

    Literature from organizational and social psychology has suggested that three types of factors influence performance, i.e., cognitive, affective and behavioral. A model was developed to test a set of propositions concerning the relationship between the three kinds of factors, and included attributions, expectancies, general emotional responses to…

  12. Principals' Perception regarding Factors Affecting the Performance of Teachers

    ERIC Educational Resources Information Center

    Akram, Muhammad Javaid; Raza, Syed Ahmad; Khaleeq, Abdur Rehman; Atika, Samrana

    2011-01-01

    This study investigated the perception of principals on how the factors of subject mastery, teaching methodology, personal characteristics, and attitude toward students affect the performance of teachers at higher secondary level in the Punjab. All principals of higher secondary level in the Punjab were part of the population of the study. From…

  13. Factors Affecting Performance in an Introductory Sociology Course

    ERIC Educational Resources Information Center

    Kwenda, Maxwell

    2011-01-01

    This study examines factors affecting students' performances in an Introductory Sociology course over five semesters. Employing simple and ordered logit regression models, the author explains final grades by focusing on individual demographic and educational characteristics that students bring into the classroom. The results show that a student's…

  14. Sibsize, Family Environment, Cognitive Performance, and Affective Characteristics

    ERIC Educational Resources Information Center

    Marjoribanks, Kevin

    1976-01-01

    Incorporates measures of family environment (parent-child interaction) into research methodology to study the effects of sibsize (family size and birth order) on a child's cognitive performance and affective behavior. Provides tentative support for the confluence model of sibsize influences on children's behaviors. (RL)

  15. Relations between affective music and speech: evidence from dynamics of affective piano performance and speech production

    PubMed Central

    Liu, Xiaoluan; Xu, Yi

    2015-01-01

    This study compares affective piano performance with speech production from the perspective of dynamics: unlike previous research, this study uses finger force and articulatory effort as indexes reflecting the dynamics of affective piano performance and speech production respectively. Moreover, for the first time physical constraints such as piano fingerings and speech articulatory constraints are included due to their potential contribution to different patterns of dynamics. A piano performance experiment and speech production experiment were conducted in four emotions: anger, fear, happiness and sadness. The results show that in both piano performance and speech production, anger and happiness generally have high dynamics while sadness has the lowest dynamics. Fingerings interact with fear in the piano experiment and articulatory constraints interact with anger in the speech experiment, i.e., large physical constraints produce significantly higher dynamics than small physical constraints in piano performance under the condition of fear and in speech production under the condition of anger. Using production experiments, this study firstly supports previous perception studies on relations between affective music and speech. Moreover, this is the first study to show quantitative evidence for the importance of considering motor aspects such as dynamics in comparing music performance and speech production in which motor mechanisms play a crucial role. PMID:26217252

  16. Relations between affective music and speech: evidence from dynamics of affective piano performance and speech production.

    PubMed

    Liu, Xiaoluan; Xu, Yi

    2015-01-01

    This study compares affective piano performance with speech production from the perspective of dynamics: unlike previous research, this study uses finger force and articulatory effort as indexes reflecting the dynamics of affective piano performance and speech production respectively. Moreover, for the first time physical constraints such as piano fingerings and speech articulatory constraints are included due to their potential contribution to different patterns of dynamics. A piano performance experiment and speech production experiment were conducted in four emotions: anger, fear, happiness and sadness. The results show that in both piano performance and speech production, anger and happiness generally have high dynamics while sadness has the lowest dynamics. Fingerings interact with fear in the piano experiment and articulatory constraints interact with anger in the speech experiment, i.e., large physical constraints produce significantly higher dynamics than small physical constraints in piano performance under the condition of fear and in speech production under the condition of anger. Using production experiments, this study firstly supports previous perception studies on relations between affective music and speech. Moreover, this is the first study to show quantitative evidence for the importance of considering motor aspects such as dynamics in comparing music performance and speech production in which motor mechanisms play a crucial role. PMID:26217252

  17. Structural Factors Affecting Health Examination Behavioral Intention.

    PubMed

    Huang, Hui-Ting; Kuo, Yu-Ming; Wang, Shiang-Ru; Wang, Chia-Fen; Tsai, Chung-Hung

    2016-04-01

    Disease screening instruments used for secondary prevention can facilitate early determination and treatment of pathogenic factors, effectively reducing disease incidence, mortality rates, and health complications. Therefore, people should be encouraged to receive health examinations for discovering potential pathogenic factors before symptoms occur. Here, we used the health belief model as a foundation and integrated social psychological factors and investigated the factors influencing health examination behavioral intention among the public in Taiwan. In total, 388 effective questionnaires were analyzed through structural model analysis. Consequently, this study yielded four crucial findings: (1) The established extended health belief model could effectively predict health examination behavioral intention; (2) Self-efficacy was the factor that most strongly influenced health examination behavioral intention, followed by health knowledge; (3) Self-efficacy substantially influenced perceived benefits and perceived barriers; (4) Health knowledge and social support indirectly influenced health examination behavioral intention. The preceding results can effectively increase the acceptance and use of health examination services among the public, thereby facilitating early diagnosis and treatment and ultimately reducing disease and mortality rates. PMID:27043606

  18. Structural Factors Affecting Health Examination Behavioral Intention

    PubMed Central

    Huang, Hui-Ting; Kuo, Yu-Ming; Wang, Shiang-Ru; Wang, Chia-Fen; Tsai, Chung-Hung

    2016-01-01

    Disease screening instruments used for secondary prevention can facilitate early determination and treatment of pathogenic factors, effectively reducing disease incidence, mortality rates, and health complications. Therefore, people should be encouraged to receive health examinations for discovering potential pathogenic factors before symptoms occur. Here, we used the health belief model as a foundation and integrated social psychological factors and investigated the factors influencing health examination behavioral intention among the public in Taiwan. In total, 388 effective questionnaires were analyzed through structural model analysis. Consequently, this study yielded four crucial findings: (1) The established extended health belief model could effectively predict health examination behavioral intention; (2) Self-efficacy was the factor that most strongly influenced health examination behavioral intention, followed by health knowledge; (3) Self-efficacy substantially influenced perceived benefits and perceived barriers; (4) Health knowledge and social support indirectly influenced health examination behavioral intention. The preceding results can effectively increase the acceptance and use of health examination services among the public, thereby facilitating early diagnosis and treatment and ultimately reducing disease and mortality rates. PMID:27043606

  19. Socially triggered negative affect impairs performance in simple cognitive tasks.

    PubMed

    Böttcher, Svenja; Dreisbach, Gesine

    2014-03-01

    The aim of this research was to investigate the influence of a social-evaluative context on simple cognitive tasks. While another person present in the room evaluated photographs of beautiful women or landscapes by beauty/attractiveness, female participants had to perform a combination of digit-categorization and spatial-compatibility task. There, before every trial, one of the women or landscape pictures was presented. Results showed selective performance impairments: the numerical distance effects increased on trials that followed women pictures but only, if another person concurrently evaluated these women pictures. In a second experiment, using the affective priming paradigm, the authors show that female pictures have a more negative connotation when they are concurrently evaluated by another person (social-evaluative context) than when they are not evaluated (neutral context). Together, these results suggest that the social-evaluative context triggers mild negative affective reactions to women pictures which then impair performance in an unrelated task. PMID:23423348

  20. TRITIUM RESERVOIR STRUCTURAL PERFORMANCE PREDICTION

    SciTech Connect

    Lam, P.S.; Morgan, M.J

    2005-11-10

    The burst test is used to assess the material performance of tritium reservoirs in the surveillance program in which reservoirs have been in service for extended periods of time. A materials system model and finite element procedure were developed under a Savannah River Site Plant-Directed Research and Development (PDRD) program to predict the structural response under a full range of loading and aged material conditions of the reservoir. The results show that the predicted burst pressure and volume ductility are in good agreement with the actual burst test results for the unexposed units. The material tensile properties used in the calculations were obtained from a curved tensile specimen harvested from a companion reservoir by Electric Discharge Machining (EDM). In the absence of exposed and aged material tensile data, literature data were used for demonstrating the methodology in terms of the helium-3 concentration in the metal and the depth of penetration in the reservoir sidewall. It can be shown that the volume ductility decreases significantly with the presence of tritium and its decay product, helium-3, in the metal, as was observed in the laboratory-controlled burst tests. The model and analytical procedure provides a predictive tool for reservoir structural integrity under aging conditions. It is recommended that benchmark tests and analysis for aged materials be performed. The methodology can be augmented to predict performance for reservoir with flaws.

  1. Factors Affecting Polymer Electrolyte Fuel Cells Performance and Reproducibility

    SciTech Connect

    Moller-Holst S.

    1998-11-01

    Development of fuel cells is often based on small-scale laboratory studies. Due to limited time and budgets, a minimum number of cells are usually prepared and tested, thus, conclusions about improved performance are often drawn from studies of a few cells. Generally, statistics showing the significance of an effect are seldom reported. In this work a simple PEM fuel cell electrode optimization experiment is used as an example to illustrate the importance of statistical evaluation of factors affecting cell performance. The use of fractional factorial design of experiments to reduce the number of cells that have to be studied is also addressed.

  2. Growth in body size affects rotational performance in women's gymnastics.

    PubMed

    Ackland, Timothy; Elliott, Bruce; Richards, Joanne

    2003-07-01

    National and state representative female gymnasts (n = 37), aged initially between 10 and 12 years, completed a mixed longitudinal study over 3.3 years, to investigate the effect of body size on gymnastic performance. Subjects were tested at four-monthly intervals on a battery of measures including structural growth, strength and gymnastic performance. The group were divided into 'high growers' and 'low growers' based on height (> 18 cm or < 14 cm/37 months, respectively) and body mass (> 15 kg or < 12 kg/37 months, respectively) for comparative purposes. Development of gymnastic performance was assessed through generic skills (front and back rotations, a twisting jump and a V-sit action) and a vertical jump for maximum height. The results show that the smaller gymnast, with a high strength to mass ratio, has greater potential for performing skills involving whole-body rotations. Larger gymnasts, while able to produce more power and greater angular momentum, could not match the performance of the smaller ones. The magnitude of growth experienced by the gymnast over this period has a varying effect on performance. While some activities were greatly influenced by rapid increases in whole-body moment of inertia (e.g. back rotation), performance on others like the front rotation and vertical jump, appeared partly immune to the physical and mechanical changes associated with growth. PMID:14737925

  3. Can small shifts in circadian phase affect performance?

    PubMed Central

    Burgess, Helen J.; Legasto, Carlo S.; Fogg, Louis F.; Smith, Mark R.

    2012-01-01

    Small shifts in circadian timing occur frequently as a result of daylight saving time or later weekend sleep. These subtle shifts in circadian phase have been shown to influence subjective sleepiness, but it remains unclear if they can significantly affect performance. In a retrospective analysis we examined performance on the Psychomotor Vigilance Test before bedtime and after wake time in 11 healthy adults on fixed sleep schedules based on their habitual sleep times. The dim light melatonin onset, a marker of circadian timing, was measured on two occasions. An average 1.1 hour shift away from a proposed optimal circadian phase angle (6 hours between melatonin onset and midpoint of sleep) significantly slowed mean, median and fastest 10% reaction times before bedtime and after wake time (p<0.05). These results add to previous reports that suggest that humans may be sensitive to commonly occurring small shifts in circadian timing. PMID:22695081

  4. Students' Interest in Surgery Affects Laparoscopic Practicing Performance

    PubMed Central

    Mao Wu, Sheng; Kuei Chien, Wen; Sheng Huang, Chen; Cheng Lin, Wei; Chun Chang, Yin

    2016-01-01

    Background and Objective: Earlier exposure to laparoscopic techniques is thought to be beneficial for medical students. Reports have demonstrated that practice improves performance in laparoscopies. In this study, we intended to evaluate whether medical students' interest in surgery is affected by the amount of practice and the performance on a laparoscopic simulator. Methods: A laparoscopic simulation curriculum was introduced at Taipei Medical University, Wan-Fang Medical Center. Study participants included 36 sixth-year and 14 seventh-year students who were divided according to whether they had indicated an interest (group A) or not (group B) in surgery. The students had twice-a-week practice sessions for 2 weeks. They underwent baseline measurement (BM) before training and posttraining measurement (PTM). Self-guided practice on the simulator was allowed. The learning outcomes were assessed comparing the BM and PTM scores by using the interquartile range (IQR) test. We also tested the correlation between total score and number of self-guided practice sessions. Results: All study participants showed improvement. No differences were observed between BM and PTM scores and between 6th- and 7th-year medical students. Significant differences were found in PTM scores between groups A and B (P < .001). Analysis of variance with a post hoc test for different groups revealed that the PTMs were significantly higher for both the 6th- and 7th-year medical students in group A than for those in group B (P < .001). Total performance scores were improved with a higher number of self-guided practice sessions. Linear regression analysis demonstrated a significant correlation between the number of self-guided practice sessions and total performance score (P < .001). Conclusion: Those clerks and interns interested in surgery who had more sessions for self-guided practice, displayed more improvement than those not interested in surgery did. Improvement in performance correlated

  5. Irrelevant events affect voters' evaluations of government performance

    PubMed Central

    Healy, Andrew J.; Malhotra, Neil; Mo, Cecilia Hyunjung

    2010-01-01

    Does information irrelevant to government performance affect voting behavior? If so, how does this help us understand the mechanisms underlying voters’ retrospective assessments of candidates’ performance in office? To precisely test for the effects of irrelevant information, we explore the electoral impact of local college football games just before an election, irrelevant events that government has nothing to do with and for which no government response would be expected. We find that a win in the 10 d before Election Day causes the incumbent to receive an additional 1.61 percentage points of the vote in Senate, gubernatorial, and presidential elections, with the effect being larger for teams with stronger fan support. In addition to conducting placebo tests based on postelection games, we demonstrate these effects by using the betting market's estimate of a team's probability of winning the game before it occurs to isolate the surprise component of game outcomes. We corroborate these aggregate-level results with a survey that we conducted during the 2009 NCAA men's college basketball tournament, where we find that surprising wins and losses affect presidential approval. An experiment embedded within the survey also indicates that personal well-being may influence voting decisions on a subconscious level. We find that making people more aware of the reasons for their current state of mind reduces the effect that irrelevant events have on their opinions. These findings underscore the subtle power of irrelevant events in shaping important real-world decisions and suggest ways in which decision making can be improved. PMID:20615955

  6. Irrelevant events affect voters' evaluations of government performance.

    PubMed

    Healy, Andrew J; Malhotra, Neil; Mo, Cecilia Hyunjung

    2010-07-20

    Does information irrelevant to government performance affect voting behavior? If so, how does this help us understand the mechanisms underlying voters' retrospective assessments of candidates' performance in office? To precisely test for the effects of irrelevant information, we explore the electoral impact of local college football games just before an election, irrelevant events that government has nothing to do with and for which no government response would be expected. We find that a win in the 10 d before Election Day causes the incumbent to receive an additional 1.61 percentage points of the vote in Senate, gubernatorial, and presidential elections, with the effect being larger for teams with stronger fan support. In addition to conducting placebo tests based on postelection games, we demonstrate these effects by using the betting market's estimate of a team's probability of winning the game before it occurs to isolate the surprise component of game outcomes. We corroborate these aggregate-level results with a survey that we conducted during the 2009 NCAA men's college basketball tournament, where we find that surprising wins and losses affect presidential approval. An experiment embedded within the survey also indicates that personal well-being may influence voting decisions on a subconscious level. We find that making people more aware of the reasons for their current state of mind reduces the effect that irrelevant events have on their opinions. These findings underscore the subtle power of irrelevant events in shaping important real-world decisions and suggest ways in which decision making can be improved. PMID:20615955

  7. Factors Affecting Exercise Test Performance in Patients After Liver Transplantation

    PubMed Central

    Kotarska, Katarzyna; Wunsch, Ewa; Jodko, Lukasz; Raszeja-Wyszomirska, Joanna; Bania, Izabela; Lawniczak, Malgorzata; Bogdanos, Dimitrios; Kornacewicz-Jach, Zdzislawa; Milkiewicz, Piotr

    2016-01-01

    Background Cardiovascular diseases are a leading cause of morbidity and mortality in solid organ transplant recipients. In addition, low physical activity is a risk factor for cardiac and cerebrovascular complications. Objectives This study examined potential relationships between physical activity, health-related quality of life (HRQoL), risk factors for cardiovascular disease, and an exercise test in liver-graft recipients. Patients and Methods A total of 107 participants (62 men/45 women) who had received a liver transplantation (LT) at least 6 months previously were evaluated. Physical activity was assessed using three different questionnaires, while HRQoL was assessed using the medical outcomes study short form (SF)-36 questionnaire, and health behaviors were evaluated using the health behavior inventory (HBI). The exercise test was performed in a standard manner. Results Seven participants (6.5%) had a positive exercise test, and these individuals were older than those who had a negative exercise test (P = 0.04). A significant association between a negative exercise test and a higher level of physical activity was shown by the Seven-day physical activity recall questionnaire. In addition, HRQoL was improved in various domains of the SF-36 in participants who had a negative exercise test. No correlations between physical activity, the exercise test and healthy behaviors, as assessed via the HBI were observed. Conclusions Exercise test performance was affected by lower quality of life and lower physical activity after LT. With the exception of hypertension, well known factors that affect the risk of coronary artery disease had no effect on the exercise test results. PMID:27226801

  8. Factors Affecting Soil Microbial Community Structure in Tomato Cropping Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and rhizosphere microbial communities in agroecosystems may be affected by soil, climate, plant species, and management. We identified some of the most important factors controlling microbial biomass and community structure in an agroecosystem utilizing tomato plants with the following nine tre...

  9. The eccentricity effect: target eccentricity affects performance on conjunction searches.

    PubMed

    Carrasco, M; Evert, D L; Chang, I; Katz, S M

    1995-11-01

    The serial pattern found for conjunction visual-search tasks has been attributed to covert attentional shifts, even though the possible contributions of target location have not been considered. To investigate the effect of target location on orientation x color conjunction searches, the target's duration and its position in the display were manipulated. The display was present either until observers responded (Experiment 1), for 104 msec (Experiment 2), or for 62 msec (Experiment 3). Target eccentricity critically affected performance: A pronounced eccentricity effect was very similar for all three experiments; as eccentricity increased, reaction times and errors increased gradually. Furthermore, the set-size effect became more pronounced as target eccentricity increased, and the extent of the eccentricity effect increased for larger set sizes. In addition, according to stepwise regressions, target eccentricity as well as its interaction with set size were good predictors of performance. We suggest that these findings could be explained by spatial-resolution and lateral-inhibition factors. The serial self-terminating hypothesis for orientation x color conjunction searches was evaluated and rejected. We compared the eccentricity effect as well as the extent of the orientation asymmetry in these three conjunction experiments with those found in feature experiments (Carrasco & Katz, 1992). The roles of eye movements, spatial resolution, and covert attention in the eccentricity effect, as well as their implications, are discussed. PMID:8539099

  10. Distraction affects the performance of obstacle avoidance during walking.

    PubMed

    Weerdesteyn, V; Schillings, A M; van Galen, G P; Duysens, J

    2003-03-01

    In this study, dual-task interference in obstacle-avoidance tasks during human walking was examined. Ten healthy young adults participated in the experiment. While they were walking on a treadmill, an obstacle suddenly fell on the treadmill in front of their left leg during either midswing, early stance, or late stance of the ipsilateral leg. Participants were instructed to avoid the obstacle, both as a single task and while they were concurrently performing a cognitive secondary task (dual task). Rates of failure, avoidance strategy, and a number of kinematic parameters were studied under both task conditions. When only a short response time was available, rates of failure on the avoidance task were larger during the dual task than during the single task. Smaller crossing swing velocities were found during the dual task as compared with those observed in the single task. The difference in crossing swing velocities was attributable to increased stiffness of the crossing swing limb. The results of the present study indicated that divided attention affects young and healthy individuals' obstacle-avoidance performance during walking. PMID:12724099

  11. Outcomes in cochlear implantation: variables affecting performance in adults and children.

    PubMed

    Cosetti, Maura K; Waltzman, Susan B

    2012-02-01

    This article highlights variables that affect cochlear implant performance, emerging factors warranting consideration, and variables shown not to affect performance. Research on the outcomes following cochlear implantation has identified a wide spectrum of variables known to affect pos0timplantation performance. These variables relate to the device itself as well as individual patient characteristics. Factors believed to affect spiral ganglion cell survival and function have been shown to influence postoperative performance. Binaural hearing affects performance. Social and educational factors also affect postoperative performance. Novel variables capable of affecting performance continue to emerge with increased understanding of auditory pathway development and neural plasticity. PMID:22115688

  12. Oligosaccharides Affect Performance and Gut Development of Broiler Chickens

    PubMed Central

    Ao, Z.; Choct, M.

    2013-01-01

    The effects of oligosaccharide supplementation on the growth performance, flock uniformity and GIT development of broiler chickens were investigated. Four diets, one negative control, one positive control supplemented with zinc-bacitracin, and two test diets supplemented with mannoligosaccharide (MOS) and fructooligosaccharide (FOS), were used for the experiment. Birds given MOS or FOS had improved body weight (BW) and feed efficiency (FCR), compared to those fed the negative control diet during the 35-d trial period. The effect on FCR became less apparent when the birds got older. FOS and MOS supplementation reduced the pancreas weight as a percentage of BW, with an effect similar to that of the antibiotic, at 35 d of age. Birds given MOS tended to have a heavier bursa (p = 0.164) and lower spleen/bursa weight ratio (p = 0.102) at 35 d of age. MOS and Zn-bacitracin showed a clear improvement on flock uniformity, compared to FOS. The mortality rate was not affected by FOS or MOS. PMID:25049713

  13. How neighbor canopy architecture affects target plant performance

    SciTech Connect

    Tremmel, D.C.; Bazzaz, F.A. )

    1993-10-01

    Plant competition occurs through the negative effects that individual plants have on resource availability to neighboring individuals. Therefore competition experiments need to examine how different species change resource availability to their neighbors, and how different species respond to these changes-allocationally, architecturally, and physiologically-through time. In a greenhouse study we used a model system of annuals to examine how canopies of species having differing morphologies differed in their architectures and light-interception abilities, and how different species performed when grown in these canopies. Abutilon theophrasti, Datura stramonium, and Polygonum pensylvanicum were grown as [open quotes]targets[close quotes]. Plants were grown in pots, with one target plant and four neighbor plants. Detailed measurements of neighbor canopy structure and target plant canopy architecture were made at five harvests. Species with different morphologies showed large differences in canopy structure, particularly when grass and forb species were compared. Setaria, a grass, had a more open canopy than the other species (all forbs), and was a consistently weak competitor. Overall, however, the relative effects of different neighbors on target biomass varied with target species. Target biomass was poorly correlated with neighbor biomass and leaf area, but was highly correlated with a measure of target light-interception ability that took into account both target leaf deployment and neighbor light interception. Despite clear differences among neighbor species in canopy structure and effect on light penetration, the results suggest no broad generalizations about the effects of different species as neighbors. Knowledge of morphological, physiological, and life history characteristics of both the target and neighbor species may be necessary to explain the results of their competition. 53 refs., 4 figs., 4 tabs.

  14. Interaction Between Optical and Neural Factors Affecting Visual Performance

    NASA Astrophysics Data System (ADS)

    Sabesan, Ramkumar

    The human eye suffers from higher order aberrations, in addition to conventional spherical and cylindrical refractive errors. Advanced optical techniques have been devised to correct them in order to achieve superior retinal image quality. However, vision is not completely defined by the optical quality of the eye, but also depends on how the image quality is processed by the neural system. In particular, how neural processing is affected by the past visual experience with optical blur has remained largely unexplored. The objective of this thesis was to investigate the interaction of optical and neural factors affecting vision. To achieve this goal, pathological keratoconic eyes were chosen as the ideal population to study since they are severely afflicted by degraded retinal image quality due to higher order aberrations and their neural system has been exposed to that habitually for a long period of time. Firstly, we have developed advanced customized ophthalmic lenses for correcting the higher order aberration of keratoconic eyes and demonstrated their feasibility in providing substantial visual benefit over conventional corrective methodologies. However, the achieved visual benefit was significantly smaller than that predicted optically. To better understand this, the second goal of the thesis was set to investigate if the neural system optimizes its underlying mechanisms in response to the long-term visual experience with large magnitudes of higher order aberrations. This study was facilitated by a large-stroke adaptive optics vision simulator, enabling us to access the neural factors in the visual system by manipulating the limit imposed by the optics of the eye. Using this instrument, we have performed a series of experiments to establish that habitual exposure to optical blur leads to an alteration in neural processing thereby alleviating the visual impact of degraded retinal image quality, referred to as neural compensation. However, it was also found that

  15. Long-term management of AAR-affected structures - An international perspective

    SciTech Connect

    Charlwood, R.G.; Solymar, Z.V.

    1995-12-31

    The objective of the paper is to review international practice and comment on progress made in the long-term management of existing AAR-affected dams and hydroelectric plants. A updated detailed worldwide listing which now includes 104 AAR-affected structures constructed since 1900 will be presented. The listing gives summary data on the year of construction, the year that significant problems were noted, aggregate and cement types, measured expansion rates, test data, time to initial deterioration, duration of reaction, damage to the structures and effects on equipment, and repairs or replacement. A comprehensive bibliography will also be given. Analysis of the database and significant case histories will be used to identify issues affecting dam safety, plant operations, remedial measures and long-term performance of AAR-affected structures. The presentation will be illustrated by several case histories where remedial measures have been implemented.

  16. Does medical students’ clinical performance affect their actual performance during medical internship?

    PubMed Central

    Han, Eui-Ryoung; Chung, Eun-Kyung

    2016-01-01

    INTRODUCTION This study examines the relationship between the clinical performance of medical students and their performance as doctors during their internships. METHODS This retrospective study involved 63 applicants of a residency programme conducted at Chonnam National University Hospital, South Korea, in November 2012. We compared the performance of the applicants during their internship with their clinical performance during their fourth year of medical school. The performance of the applicants as interns was periodically evaluated by the faculty of each department, while their clinical performance as fourth-year medical students was assessed using the Clinical Performance Examination (CPX) and the Objective Structured Clinical Examination (OSCE). RESULTS The performance of the applicants as interns was positively correlated with their clinical performance as fourth-year medical students, as measured by the CPX and OSCE. The performance of the applicants as interns was moderately correlated with the patient-physician interaction items addressing communication and interpersonal skills in the CPX. CONCLUSION The clinical performance of medical students during their fourth year in medical school was related to their performance as medical interns. Medical students should be trained to develop good clinical skills through actual encounters with patients or simulated encounters using manikins, to enable them to become more competent doctors. PMID:26768172

  17. How spatio-temporal habitat connectivity affects amphibian genetic structure

    PubMed Central

    Watts, Alexander G.; Schlichting, Peter E.; Billerman, Shawn M.; Jesmer, Brett R.; Micheletti, Steven; Fortin, Marie-Josée; Funk, W. Chris; Hapeman, Paul; Muths, Erin; Murphy, Melanie A.

    2015-01-01

    Heterogeneous landscapes and fluctuating environmental conditions can affect species dispersal, population genetics, and genetic structure, yet understanding how biotic and abiotic factors affect population dynamics in a fluctuating environment is critical for species management. We evaluated how spatio-temporal habitat connectivity influences dispersal and genetic structure in a population of boreal chorus frogs (Pseudacris maculata) using a landscape genetics approach. We developed gravity models to assess the contribution of various factors to the observed genetic distance as a measure of functional connectivity. We selected (a) wetland (within-site) and (b) landscape matrix (between-site) characteristics; and (c) wetland connectivity metrics using a unique methodology. Specifically, we developed three networks that quantify wetland connectivity based on: (i) P. maculata dispersal ability, (ii) temporal variation in wetland quality, and (iii) contribution of wetland stepping-stones to frog dispersal. We examined 18 wetlands in Colorado, and quantified 12 microsatellite loci from 322 individual frogs. We found that genetic connectivity was related to topographic complexity, within- and between-wetland differences in moisture, and wetland functional connectivity as contributed by stepping-stone wetlands. Our results highlight the role that dynamic environmental factors have on dispersal-limited species and illustrate how complex asynchronous interactions contribute to the structure of spatially-explicit metapopulations. PMID:26442094

  18. How spatio-temporal habitat connectivity affects amphibian genetic structure

    USGS Publications Warehouse

    Watts, Alexander G.; Schlichting, P; Billerman, S; Jesmer, B; Micheletti, S; Fortin, M.-J.; Funk, W.C.; Hapeman, P; Muths, Erin L.; Murphy, M.A.

    2015-01-01

    Heterogeneous landscapes and fluctuating environmental conditions can affect species dispersal, population genetics, and genetic structure, yet understanding how biotic and abiotic factors affect population dynamics in a fluctuating environment is critical for species management. We evaluated how spatio-temporal habitat connectivity influences dispersal and genetic structure in a population of boreal chorus frogs (Pseudacris maculata) using a landscape genetics approach. We developed gravity models to assess the contribution of various factors to the observed genetic distance as a measure of functional connectivity. We selected (a) wetland (within-site) and (b) landscape matrix (between-site) characteristics; and (c) wetland connectivity metrics using a unique methodology. Specifically, we developed three networks that quantify wetland connectivity based on: (i) P. maculata dispersal ability, (ii) temporal variation in wetland quality, and (iii) contribution of wetland stepping-stones to frog dispersal. We examined 18 wetlands in Colorado, and quantified 12 microsatellite loci from 322 individual frogs. We found that genetic connectivity was related to topographic complexity, within- and between-wetland differences in moisture, and wetland functional connectivity as contributed by stepping-stone wetlands. Our results highlight the role that dynamic environmental factors have on dispersal-limited species and illustrate how complex asynchronous interactions contribute to the structure of spatially-explicit metapopulations.

  19. An Analysis of Team Composition as It Affects Simulation Performance.

    ERIC Educational Resources Information Center

    Krishnakumar, Parameswar; Chisholm, Thomas Alexander

    This study investigated the extent to which sex composition and average team academic achievement of student simulation teams affect team effectiveness. Seventy-four students in two sections of a marketing principles class were divided into 20 teams to test their decision-making skills. For 10 weeks, each team operated a simulated supermarket…

  20. How differentiated do children experience affect? An investigation of the within- and between-person structure of children's affect.

    PubMed

    Leonhardt, Anja; Könen, Tanja; Dirk, Judith; Schmiedek, Florian

    2016-05-01

    Research on the structure of children's affect is limited. It is possible that children's perception of their own affect might be less differentiated than that of adults. Support for the 2-factor model of positive and negative affect and the pleasure-arousal model suggests that children in middle childhood can distinguish positive and negative affect as well as valence and arousal. Whether children are able to differentiate further aspects of affect, as proposed by the 3-dimensional model of affect (good-bad mood, alertness-tiredness, calmness-tension), is an unresolved issue. The aim of our study was the comparison of these 3 affect models to establish how differentiated children experience their affect and which model best describes affect in children. We examined affect structures on the between- and within-person level, acknowledging that affect varies across time and that no valid interpretation of either level is feasible if both are confounded. For this purpose, 214 children (age 8-11 years) answered affect items once a day for 5 consecutive days on smartphones. We tested all affect models by means of 2-level confirmatory factor analysis. Although all affect models had an acceptable fit, the 3-dimensional model best described affect in children on both the within- and between-person level. Thus, children in middle childhood can already describe affect in a differentiated way. Also, affect structures were similar on the within- and between-person level. We conclude that in order to acquire a thorough picture of children's affect, measures for children should include items of all 3 affect dimensions. (PsycINFO Database Record PMID:26280488

  1. Factors Affecting the Performance of Public Schools in Lebanon

    ERIC Educational Resources Information Center

    Mattar, Dorine M.

    2012-01-01

    By sampling extreme cases (five high-performing schools and five low-performing ones), the researcher revealed the differences in the teachers' motivation (Mattar, 2010) as well as the extent to which Principals adopted the instructional leadership style (Mattar, 2012) in the two sets of schools. Here, she looked for additional issues, within the…

  2. Learners' Metalinguistic and Affective Performance in Blogging to Write

    ERIC Educational Resources Information Center

    Chen, Ping-Ju

    2016-01-01

    The documentation of the benefits of blog use in foreign language education has proliferated since 2006. In the field of blogging to write, most studies focus on learners' linguistic performance and perceptions. To provide an analysis of learners' writing performance by using blogs, in addition to the often-researched areas, this study examines…

  3. Young Children's Knowledge About Effects of Affect on Performance.

    ERIC Educational Resources Information Center

    Pierce, Jean W.

    1985-01-01

    Addresses the issue of whether preschoolers are aware of the connection between their emotions, their performance on a task of eye-hand coordination, and their evaluation of the task and their performance. Results indicate a developmental trend that children's predictions conform more to mood congruity theory as they grow older. (Author/DST)

  4. Can the structure of an explosive caldera affect eruptive behaviour?

    NASA Astrophysics Data System (ADS)

    Willcox, C. P.; Branney, M.; Carrasco-Nuñez, G.; Barford, D.

    2010-12-01

    Explosive caldera volcanoes cause catastrophic events at the Earth’s surface, yet we know little about how their internal structures evolve with time, and whether this can affect both differentiation and eruptive behaviour. Distinguishing how structural evolution impacts upon eruption behaviour and periodicity is challenging because the resolution of eruption frequencies can be difficult at ancient exhumed calderas, whereas at young volcanoes, most of the caldera floor faults and associated conduits are hidden. Some exhumed calderas reveal caldera floor faults and conduits; some of these apparently underwent a single collapse event that was piecemeal, i.e. fragmentation into several, variously subsided fault-blocks (e.g. Scafell caldera, UK). In contrast, the present study tests whether some caldera volcanoes may become more intensely fractured with time as a result of successive distinct caldera-collapse eruptions (“multi-cyclic calderas”). It has been proposed that this scenario could lead to an increase in eruption frequency, with smaller eruptions over time. Magma leakage through the increasingly fractured volcano might also lead to less evolved compositions with time due to shorter residence times. We have returned to the volcano where this hypothesis was formulated, the ~ 20 km diameter, hydrothermally active Los Humeros caldera in eastern central México. We aim to see how well the structural evolution of this modern caldera can be reconstructed, and whether changes in structure affected the styles and periodicity of large explosive eruptions. How a caldera evolves structurally could have important implications for predicting future catastrophic eruptions. Detailed structural mapping (e.g. of fault scarps, vent positions, and tilted strata), documentation of draping and cross-cutting field relations, together with logging, optical and SEM petrography, XRF major and trace element geochemistry and new 40Ar-39Ar and radiocarbon dating of the pyroclastic

  5. Wintering performance and how it affects carcass quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental variation undoubtedly can have the most significant impact on livestock performance in forage based production systems. Fluctuations in temperature and precipitation influence herbage production and quality, maintenance requirements and intake. Producers of “forage system” products h...

  6. Factors affecting intrauterine contraceptive device performance. I. Endometrial cavity length.

    PubMed

    Hasson, H M; Berger, G S; Edelman, D A

    1976-12-15

    The relationship of endometrial cavity length to intrauterine contraceptive device (IUD) performance was evaluated in 319 patients wearing three types of devices. The rate of events, defined as pregnancy, expulsion, or medical removal, increased significantly when the length of the IUD was equal to, exceeded, or was shorter by two or more centimeters than the length of the endometrial cavity. Total uterine length was found to be a less accurate prognostic indicator of IUD performance than endometrial cavity length alone. PMID:998687

  7. Operational experience with VAWT blades. [structural performance

    NASA Technical Reports Server (NTRS)

    Sullivan, W. N.

    1979-01-01

    The structural performance of 17 meter diameter wind turbine rotors is discussed. Test results for typical steady and vibratory stress measurements are summarized along with predicted values of stress based on a quasi-static finite element model.

  8. When children affect parents: Children's academic performance and parental investment.

    PubMed

    Yurk Quadlin, Natasha

    2015-07-01

    Sociologists have extensively documented the ways that parent resources predict children's achievement. However, less is known about whether and how children's academic performance shapes parental investment behaviors. I use data from the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K) and longitudinal fixed effects models to examine how changes in teacher assessments are related to changes in the conferral of various parent resources. Overall, I find that the relationship between achievement and investment varies based on the directionality in children's achievement and the type of resource at hand. Children whose performance improves receive a broad range of enrichment resources, while declines in performance are met with corrective educational resources. Results are largely consistent whether language or math assessments are used to predict investment, and also among children whose achievement does not change over time. I discuss these patterns, along with implications for the use of parent resources in education and family research. PMID:26004488

  9. Hyperlipidemia affects multiscale structure and strength of murine femur

    PubMed Central

    Ascenzi, Maria-Grazia; Lutz, Andre; Du, Xia; Klimecky, Laureen; Kawas, Neal; Hourany, Talia; Jahng, Joelle; Chin, Jesse; Tintut, Yin; Nackenhors, Udo; Keyak, Joyce

    2014-01-01

    To improve bone strength prediction beyond limitations of assessment founded solely on the bone mineral component, we investigated the effect of hyperlipidemia, present in more than 40% of osteoporotic patients, on multiscale structure of murine bone. Our overarching purpose is to estimate bone strength accurately, to facilitate mitigating fracture morbidity and mortality in patients. Because i) orientation of collagen type I affects, independently of degree of mineralization, cortical bone’s micro-structural strength; and, ii) hyperlipidemia affects collagen orientation and µCT volumetric tissue mineral density (vTMD) in murine cortical bone, we have constructed the first multiscale finite element (mFE), mouse-specific femoral model to study the effect of collagen orientation and vTMD on strength in Ldlr−/−, a mouse model of hyperlipidemia, and its control wild type, on either high fat diet or normal diet. Each µCT scan-based mFE model included either element-specific elastic orthotropic properties calculated from collagen orientation and vTMD (collagen-density model) by experimentally validated formulation, or usual element-specific elastic isotropic material properties dependent on vTMD-only (density-only model). We found that collagen orientation, assessed by circularly polarized light and confocal microscopies, and vTMD, differed among groups; and that microindentation results strongly correlate with elastic modulus of collagen-density models (r2=0.85, p=10−5). Collagen-density models yielded 1) larger strains, and therefore lower strength, in simulations of 3-point bending and physiological loading; and 2) higher correlation between mFE-predicted strength and 3-point bending experimental strength, than density-only models. This novel method supports ongoing translational research to achieve the as yet elusive goal of accurate bone strength prediction. PMID:24795172

  10. Hyperlipidemia affects multiscale structure and strength of murine femur.

    PubMed

    Ascenzi, Maria-Grazia; Lutz, Andre; Du, Xia; Klimecky, Laureen; Kawas, Neal; Hourany, Talia; Jahng, Joelle; Chin, Jesse; Tintut, Yin; Nackenhors, Udo; Keyak, Joyce

    2014-07-18

    To improve bone strength prediction beyond limitations of assessment founded solely on the bone mineral component, we investigated the effect of hyperlipidemia, present in more than 40% of osteoporotic patients, on multiscale structure of murine bone. Our overarching purpose is to estimate bone strength accurately, to facilitate mitigating fracture morbidity and mortality in patients. Because (i) orientation of collagen type I affects, independently of degree of mineralization, cortical bone׳s micro-structural strength; and, (ii) hyperlipidemia affects collagen orientation and μCT volumetric tissue mineral density (vTMD) in murine cortical bone, we have constructed the first multiscale finite element (mFE), mouse-specific femoral model to study the effect of collagen orientation and vTMD on strength in Ldlr(-/-), a mouse model of hyperlipidemia, and its control wild type, on either high fat diet or normal diet. Each µCT scan-based mFE model included either element-specific elastic orthotropic properties calculated from collagen orientation and vTMD (collagen-density model) by experimentally validated formulation, or usual element-specific elastic isotropic material properties dependent on vTMD-only (density-only model). We found that collagen orientation, assessed by circularly polarized light and confocal microscopies, and vTMD, differed among groups and that microindentation results strongly correlate with elastic modulus of collagen-density models (r(2)=0.85, p=10(-5)). Collagen-density models yielded (1) larger strains, and therefore lower strength, in simulations of 3-point bending and physiological loading; and (2) higher correlation between mFE-predicted strength and 3-point bending experimental strength, than density-only models. This novel method supports ongoing translational research to achieve the as yet elusive goal of accurate bone strength prediction. PMID:24795172

  11. Designing transthyretin mutants affecting tetrameric structure: implications in amyloidogenicity.

    PubMed Central

    Redondo, C; Damas, A M; Saraiva, M J

    2000-01-01

    The molecular mechanisms that convert soluble transthyretin (TTR) tetramers into insoluble amyloid fibrils are still unknown; dissociation of the TTR tetramer is a pre-requisite for amyloid formation in vitro and involvement of monomers and/or dimers in fibril formation has been suggested by structural studies. We have designed four mutated proteins with the purpose of stabilizing [Ser(117)-->Cys (S117C) and Glu(92)-->Cys (E92C)] or destabilizing [Asp(18)-->Asn (D18N) and Leu(110)-->Ala (D110A)] the dimer/tetramer interactions in TTR, aiming at elucidating structural determinants in amyloidogenesis. The resistance of the mutated proteins to dissociation was analysed by HPLC studies of diluted TTR preparations. Both 'stabilized' mutants migrated as tetramers and, upon dilution, no other TTR species was observed, confirming the increased resistance to dissociation. For the 'destabilized' mutants, a mixture of tetrameric and monomeric forms co-existed at low dilution and the latter increased upon 10-fold dilution. Both of the destabilizing mutants formed amyloid in vitro when acidified. This result indicated that both the AB loop of TTR, destabilized in D18N, and the hydrophobic interactions affecting the dimer-dimer interfaces in L110A are implicated in the stability of the tetrameric structure. The stabilized mutants, which were dimeric in nature through disulphide bonding, were unable to polymerize into amyloid, even at pH 3.2. When the amyloid formation assay was repeated in the presence of 2-mercaptoethanol, upon disruption of the S-S bridges of these stable dimers, amyloid fibril formation was observed. This experimental evidence suggests that monomers, rather than dimers, are the repeating structural subunit comprising the amyloid fibrils. PMID:10794728

  12. Advanced Technology Composite Fuselage-Structural Performance

    NASA Technical Reports Server (NTRS)

    Walker, T. H.; Minguet, P. J.; Flynn, B. W.; Carbery, D. J.; Swanson, G. D.; Ilcewicz, L. B.

    1997-01-01

    Boeing is studying the technologies associated with the application of composite materials to commercial transport fuselage structure under the NASA-sponsored contracts for Advanced Technology Composite Aircraft Structures (ATCAS) and Materials Development Omnibus Contract (MDOC). This report addresses the program activities related to structural performance of the selected concepts, including both the design development and subsequent detailed evaluation. Design criteria were developed to ensure compliance with regulatory requirements and typical company objectives. Accurate analysis methods were selected and/or developed where practical, and conservative approaches were used where significant approximations were necessary. Design sizing activities supported subsequent development by providing representative design configurations for structural evaluation and by identifying the critical performance issues. Significant program efforts were directed towards assessing structural performance predictive capability. The structural database collected to perform this assessment was intimately linked to the manufacturing scale-up activities to ensure inclusion of manufacturing-induced performance traits. Mechanical tests were conducted to support the development and critical evaluation of analysis methods addressing internal loads, stability, ultimate strength, attachment and splice strength, and damage tolerance. Unresolved aspects of these performance issues were identified as part of the assessments, providing direction for future development.

  13. Computer program performs stiffness matrix structural analysis

    NASA Technical Reports Server (NTRS)

    Bamford, R.; Batchelder, R.; Schmele, L.; Wada, B. K.

    1968-01-01

    Computer program generates the stiffness matrix for a particular type of structure from geometrical data, and performs static and normal mode analyses. It requires the structure to be modeled as a stable framework of uniform, weightless members, and joints at which loads are applied and weights are lumped.

  14. Factors Affecting School District Performance Scores in Louisiana

    ERIC Educational Resources Information Center

    Harrison, Ronnie

    2010-01-01

    The purpose of this study was to investigate the relationship between District Performance Scores (DPS) in Louisiana and (a) socio-economic status of students, (b) academic achievement using average ACT scores, (c) percentage of certified teachers, (d) district class size, (e) per pupil expenditure, and (f) percentage of minority students in…

  15. Does Participative Decision Making Affect Lecturer Performance in Higher Education?

    ERIC Educational Resources Information Center

    Sukirno, D. S.; Siengthai, Sununta

    2011-01-01

    Purpose: The relationship between participation and job performance has captured the interest of not only business researchers but also education researchers. However, the topic has not gained significant attention in the educational management research arena. The purpose of this paper is to empirically examine the impact of participation in…

  16. Teacher Dispositions Affecting Self-Esteem and Student Performance

    ERIC Educational Resources Information Center

    Helm, Carroll

    2007-01-01

    Research supports several factors related to student success. Darling-Hammond (2000) indicated that the quality of teachers, as measured by whether the teachers were fully certified and had a major in their teaching field, was related to student performance. Measures of teacher preparation and certification were the strongest predictors of student…

  17. Early Teacher Expectations Disproportionately Affect Poor Children's High School Performance

    ERIC Educational Resources Information Center

    Sorhagen, Nicole S.

    2013-01-01

    This research used prospective longitudinal data to examine the associations between first-grade teachers' over- and underestimation of their students' math abilities, basic reading abilities, and language skills and the students' high school academic performance, with special attention to the subject area and moderating effects of student…

  18. Social Process Variables Affecting Reading Performance in Delayed Readers.

    ERIC Educational Resources Information Center

    Lorton, Mary; Kukuk, Cristopher

    A study was conducted to determine the relationship between fourteen social process variables (relating to perinatal events, early language patterns, parental/home environment, and child behavior patterns) and the reading performance of retarded readers. The subjects were 180 children, aged seven through fifteen, randomly selected from among…

  19. Structural and leakage integrity of tubes affected by circumferential cracking

    SciTech Connect

    Hernalsteen, P.

    1997-02-01

    In this paper the author deals with the notion that circumferential cracks are generally considered unacceptable. He argues for the need to differentiate two facets of such cracks: the issue of the size and growth rate of a crack; and the issue of the structural strength and leakage potential of the tube in the presence of the crack. In this paper the author tries to show that the second point is not a major concern for such cracks. The paper presents data on the structural strength or burst pressure characteristics of steam generator tubes derived from models and data bases of experimental work. He also presents a leak rate model, and compares the performance of circumferential and axial cracks as far as burst strength and leak rate. The final conclusion is that subject to improvement in NDE capabilities (sizing, detection, growth), that Steam Generator Defect Specific Management can be used to allow circumferentially degraded tubes to remain in service.

  20. Scales affect performance of Monarch butterfly forewings in autorotational flight

    NASA Astrophysics Data System (ADS)

    Demko, Anya; Lang, Amy

    2012-11-01

    Butterfly wings are characterized by rows of scales (approximately 100 microns in length) that create a shingle-like pattern of cavities over the entire surface. It is hypothesized that these cavities influence the airflow around the wing and increase aerodynamic performance. A forewing of the Monarch butterfly (Danus plexippus) naturally undergoes autorotational flight in the laminar regime. Autorotational flight is an accurate representation of insect flight because the rotation induces a velocity gradient similar to that found over a flapping wing. Drop test flights of 22 forewings before and after scale removal were recorded with a high-speed camera and flight behavior was quantified. It was found that removing the scales increased the descent speed and decreased the descent factor, a measure of aerodynamic efficacy, suggesting that scales increased the performance of the forewings. Funded by NSF REU Grant 1062611.

  1. Luminance controlled pupil size affects Landolt C task performance. Revision

    SciTech Connect

    Berman, S.M.; Fein, G.; Jewett, D.L.; Ashford, F.

    1993-02-01

    Subjects judged the orientation of a 2 min. gap Landolt C located at a distance of 2.4 m. The stimuli were presented in central vision on a CRT, at low to medium contrast. The effects of varying the spectrum and luminance of surround lighting were assessed on both pupil size (measured using infrared pupillometry during task performance) and task accuracy. The task display was protected from the surround lighting, so that its luminance and contrast could be varied independently of the changes in the surround lighting. Indirect surround illumination was provided by either two illuminants of very different scotopic spectral content but with the same photopic luminance (Experiments 1 and 3), or by using the same illuminant at two different luminance levels (Experiment 2). In Experiment 3, the effect of changing surround spectrum was compared to the effect of varying task background luminance between 12 cd/m{sup 2} and 73 cd/m{sup 2}. In all experiments, scotopically enhanced surround lighting produced pupil areas which were reduced by almost 50% in comparison with surround lighting with relatively less scotopic luminance. Concomitantly there was improvement in Landolt C task performance with the scotopically enhanced surround lighting at all contrast and luminance levels. In these experiments, smaller pupil sizes were associated with significantly better visual-task performance in spite of lower task retinal illuminance when compared to the condition with larger pupils. These results suggest that changes in surround spectrum can compensate for the effect on task performance of a reduction in task luminance and supports the hypothesis that lighting energy savings could accrue in the workplace by shifting lamp spectra to obtain greater scotopic efficacy.

  2. Luminance controlled pupil size affects Landolt C task performance

    SciTech Connect

    Berman, S.M. ); Fein, G. ); Jewett, D.L.; Ashford, F. )

    1993-02-01

    Subjects judged the orientation of a 2 min. gap Landolt C located at a distance of 2.4 m. The stimuli were presented in central vision on a CRT, at low to medium contrast. The effects of varying the spectrum and luminance of surround lighting were assessed on both pupil size (measured using infrared pupillometry during task performance) and task accuracy. The task display was protected from the surround lighting, so that its luminance and contrast could be varied independently of the changes in the surround lighting. Indirect surround illumination was provided by either two illuminants of very different scotopic spectral content but with the same photopic luminance (Experiments 1 and 3), or by using the same illuminant at two different luminance levels (Experiment 2). In Experiment 3, the effect of changing surround spectrum was compared to the effect of varying task background luminance between 12 cd/m[sup 2] and 73 cd/m[sup 2]. In all experiments, scotopically enhanced surround lighting produced pupil areas which were reduced by almost 50% in comparison with surround lighting with relatively less scotopic luminance. Concomitantly there was improvement in Landolt C task performance with the scotopically enhanced surround lighting at all contrast and luminance levels. In these experiments, smaller pupil sizes were associated with significantly better visual-task performance in spite of lower task retinal illuminance when compared to the condition with larger pupils. These results suggest that changes in surround spectrum can compensate for the effect on task performance of a reduction in task luminance and supports the hypothesis that lighting energy savings could accrue in the workplace by shifting lamp spectra to obtain greater scotopic efficacy.

  3. Factors That Affect Academic Performance Among Pharmacy Students

    PubMed Central

    Sansgiry, Sujit S.; Bhosle, Monali; Sail, Kavita

    2006-01-01

    Objective The objective of this study was to examine factors such as academic competence, test competence, time management, strategic studying, and test anxiety, and identify whether these factors could distinguish differences among students, based on academic performance and enrollment in the experiential program. Methods A cross-sectional study design utilizing questionnaires measuring previously validated constructs was used to evaluate the effect of these factors on students with low and high cumulative grade point averages (GPAs). Pharmacy students (N = 198) enrolled at the University of Houston participated in the study. Results Academic performance was significantly associated with factors such as academic competence and test competence. Students with a cumulative GPA of 3.0 or greater significantly differed in their level of test competence than those with a GPA of less than 3.0. Students enrolled in their experiential year differed from students enrolled in their second year of curriculum on factors such as test anxiety, academic competence, test competence, and time management skills. Conclusion Test competence was an important factor to distinguish students with low vs. high academic performance. Factors such as academic competence, test competence, test anxiety and time management improve as students' progress in their experiential year. PMID:17149433

  4. Positive affective tone and team performance: The moderating role of collective emotional skills.

    PubMed

    Collins, Amy L; Jordan, Peter J; Lawrence, Sandra A; Troth, Ashlea C

    2016-01-01

    Research on affect as a group-level phenomenon has shown that over time, individual members within a group become highly similar in their affect (i.e., members experience and display similar emotions and moods), and often become similar enough that the aggregation of individuals' affect can meaningfully represent the "affective tone" of the group. It is generally assumed that a more positive affective tone will lead to better team performance. We challenge the conclusion that positive affective tone is always good for team performance, suggesting that the relationship between positive affective tone and team performance is subject to moderating influences. Across two studies, we demonstrate that the self-reported collective emotional skills of team members play a crucial role in determining whether positive affective tone is beneficial or detrimental to team performance. Implications for theory and practice are discussed. PMID:26208085

  5. Regression analysis of technical parameters affecting nuclear power plant performances

    SciTech Connect

    Ghazy, R.; Ricotti, M. E.; Trueco, P.

    2012-07-01

    Since the 80's many studies have been conducted in order to explicate good and bad performances of commercial nuclear power plants (NPPs), but yet no defined correlation has been found out to be totally representative of plant operational experience. In early works, data availability and the number of operating power stations were both limited; therefore, results showed that specific technical characteristics of NPPs were supposed to be the main causal factors for successful plant operation. Although these aspects keep on assuming a significant role, later studies and observations showed that other factors concerning management and organization of the plant could instead be predominant comparing utilities operational and economic results. Utility quality, in a word, can be used to summarize all the managerial and operational aspects that seem to be effective in determining plant performance. In this paper operational data of a consistent sample of commercial nuclear power stations, out of the total 433 operating NPPs, are analyzed, mainly focusing on the last decade operational experience. The sample consists of PWR and BWR technology, operated by utilities located in different countries, including U.S. (Japan)) (France)) (Germany)) and Finland. Multivariate regression is performed using Unit Capability Factor (UCF) as the dependent variable; this factor reflects indeed the effectiveness of plant programs and practices in maximizing the available electrical generation and consequently provides an overall indication of how well plants are operated and maintained. Aspects that may not be real causal factors but which can have a consistent impact on the UCF, as technology design, supplier, size and age, are included in the analysis as independent variables. (authors)

  6. Computational and experimental of railgun structural performance

    SciTech Connect

    Wellman, G.W.

    1989-12-01

    The structural response of plasma armature railguns to the electromagnetic load imposed during operation has a significant effect on performance. The railgun support structure must minimize bore deformation; thus stiffness and strength are important design parameters. The step by step evolution of the design toward a structure which will tolerate operation with 500 to 700 kA rail currents is presented. The design effort started with the traditional rail/insulator core structure contained within a V-block which provides a preload. Non-linear dynamic analyses together with model tests were used to assess the effects of changes in geometry, materials, and preload on the railgun structural performance. 39 figs., 5 tabs.

  7. Characterization of titanium dioxide: Factors affecting photocatalytic performance

    SciTech Connect

    Presley, R.W.

    1995-06-01

    Titanium dioxide is being evaluated as a photocatalyst in the destruction of contaminants in aqueous waste streams. Commercial samples of TiO{sub 2} powder have been obtained for base line studies of the photocatalytic destruction of salicylic acid standards. These commercial samples have been prepared by flame hydrolysis and aerosol or spray pyrolysis. Additional samples of TiO{sub 2} have been prepared in house by precipitation from TiCl{sub 4} in aqueous solution, some with the addition of dopants. X-ray powder diffraction data analysis indicates the predominate phase of these commercial and prepared powders to be anatase. A minor amount of the rutile crystalline phase of TiO{sub 2} was observed at various levels in some of these catalysts. The broadness of the x-ray diffraction bands varied among the samples analyzed and indicated the primary particle size to be within the 500 to 1,000 angstrom range with the product produced in house having the smallest crystallite size. Experiments were then performed to assess the photocatalytic performance of these various types of catalyst in the destruction of 30 ppm salicylic acid in deionized water.

  8. Phosphate Ions Affect the Water Structure at Functionalized Membrane Surfaces.

    PubMed

    Barrett, Aliyah; Imbrogno, Joseph; Belfort, Georges; Petersen, Poul B

    2016-09-01

    Antifouling surfaces improve function, efficiency, and safety in products such as water filtration membranes, marine vehicle coatings, and medical implants by resisting protein and biofilm adhesion. Understanding the role of water structure at these materials in preventing protein adhesion and biofilm formation is critical to designing more effective coatings. Such fouling experiments are typically performed under biological conditions using isotonic aqueous buffers. Previous studies have explored the structure of pure water at a few different antifouling surfaces, but the effect of electrolytes and ionic strength (I) on the water structure at antifouling surfaces is not well studied. Here sum frequency generation (SFG) spectroscopy is used to characterize the interfacial water structure at poly(ether sulfone) (PES) and two surface-modified PES films in contact with 0.01 M phosphate buffer with high and low salt (Ionic strength, I= 0.166 and 0.025 M, respectively). Unmodified PES, commonly used as a filtration membrane, and modified PES with a hydrophobic alkane (C18) and with a poly(ethylene glycol) (PEG) were used. In the low ionic strength phosphate buffer, water was strongly ordered near the surface of the PEG-modified PES film due to exclusion of phosphate ions and the creation of a surface potential resulting from charge separation between phosphate anions and sodium cations. However, in the high ionic strength phosphate buffer, the sodium and potassium chloride (138 and 3 mM, respectively) in the phosphate buffered saline screened this charge and substantially reduced water ordering. A much smaller water ordering and subsequent reduction upon salt addition was observed for the C18-modified PES, and little water structure change was seen for the unmodified PES. The large difference in water structuring with increasing ionic strength between widely used phosphate buffer and phosphate buffered saline at the PEG interface demonstrates the importance of studying

  9. Factors affecting the performance of large-aperture microphone arrays.

    PubMed

    Silverman, Harvey F; Patterson, William R; Sachar, Joshua

    2002-05-01

    Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m x 8 m x 3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment. PMID:12051434

  10. Factors affecting the performance of large-aperture microphone arrays

    NASA Astrophysics Data System (ADS)

    Silverman, Harvey F.; Patterson, William R.; Sachar, Joshua

    2002-05-01

    Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m×8 m×3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment.

  11. Noise Affects Performance on the Montreal Cognitive Assessment.

    PubMed

    Dupuis, Kate; Marchuk, Veronica; Pichora-Fuller, M Kathleen

    2016-09-01

    We investigated the effect of background noise on performance on the Montreal Cognitive Assessment (MoCA). Two groups of older adults (one with clinically normal hearing, one with hearing loss) and a younger adult group with clinically normal hearing were administered two versions of the MoCA under headphones in low and high levels of background noise. Intensity levels used to present the test were customized based on the hearing abilities of participants with hearing loss to yield a uniform level of difficulty across listeners in the high-level noise condition. Both older groups had poorer MoCA scores in noise than the younger group. Importantly, all participants had poorer MoCA scores in the high-noise (M = 22.7/30) compared to the low-noise condition (M = 25.7/30, p < .001). Results suggest that background noise in the test environment should be considered when cognitive tests are conducted and results interpreted, especially when testing older adults. PMID:27345572

  12. Performance of structured lipids incorporating selected phenolic and ascorbic acids.

    PubMed

    Gruczynska, Eliza; Przybylski, Roman; Aladedunye, Felix

    2015-04-15

    Conditions applied during frying require antioxidant which is stable at these conditions and provides protection for frying oil and fried food. Novel structured lipids containing nutraceuticals and antioxidants were formed by enzymatic transesterification, exploring canola oil and naturally occurring antioxidants such as ascorbic and selected phenolic acids as substrates. Lipozyme RM IM lipase from Rhizomucor miehei was used as biocatalyst. Frying performance and oxidative stability of the final transesterification products were evaluated. The novel lipids showed significantly improved frying performance compared to canola oil. Oxidative stability assessment of the structured lipids showed significant improvement in resistance to oxidative deterioration compared to original canola oil. Interestingly, the presence of ascorbic acid in an acylglycerol structure protected α-tocopherol against thermal degradation, which was not observed for the phenolic acids. Developed structured lipids containing nutraceuticals and antioxidants may directly affect nutritional properties of lipids also offering nutraceutical ingredients for food formulation. PMID:25466089

  13. Fatigue performance of welded aluminum deck structures

    SciTech Connect

    Haagensen, P.J.; Ranes, M.; Kluken, A.O.; Kvale, I.

    1996-12-01

    Aluminum alloys are used increasingly in load carrying structures where low weight and low maintenance costs are at a premium. Helicopter decks, structures for living quarters and personnel transfer bridges between platforms are examples of offshore applications. While these structures are not usually subjected to high fatigue loads, the increasing use of aluminum in high speed ships, and more recently in highway bridge structures, makes the question of fatigue performance more important. In this paper the fatigue properties of small scale weldments in an AA6005 alloy are compared with the results of fatigue tests on full scale sections of welded extrusions in the same material, which were used in an aluminum bridge deck structure. The fatigue performance is also compared with the fatigue clauses in the new British design code BS8118 for aluminium structures and the proposed Eurocode 9. The prospects of using a new joining technique, friction stir welding (FSW), in the production of large scale panels for deck and ship hull structures is discussed. The FSW process is described briefly, and some fatigue test data are presented.

  14. Affective Responses to an Aerobic Dance Class: The Impact of Perceived Performance.

    ERIC Educational Resources Information Center

    Bartholomew, John B.; Miller, Bridget M.

    2002-01-01

    Tested the mastery hypothesis as an explanation for the affective benefits of acute exercise. Undergraduate women from a self-selected aerobic dance class rated their exercise performance following class. Affect questionnaires were completed before and at 5 and 20 minutes after the class. Results showed an overall improvement in affect following…

  15. Structural-Thermal-Optical-Performance (STOP) Analysis

    NASA Technical Reports Server (NTRS)

    Bolognese, Jeffrey; Irish, Sandra

    2015-01-01

    The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard Spaceflight Center (GSFC) Thermal Engineering Branch (Code 545). A STOP analysis is a multidiscipline analysis, consisting of Structural, Thermal and Optical Performance Analyses, that is performed for all space flight instruments and satellites. This course will explain the different parts of performing this analysis. The student will learn how to effectively interact with each discipline in order to accurately obtain the system analysis results.

  16. Pipelining performance of structured dataflow networks

    SciTech Connect

    Tonge, F.M.

    1983-01-01

    A particular approach to specifying procedure interconnection and allocation is presented. The major result is that, within stated assumptions, networks constructed using a small set of structured process connectives can achieve at least as good throughput (pipelining performance) as arbitrarily interconnected networks. 20 references.

  17. Cognitive structure from childhood to adulthood in kindreds densely affected by schizophrenia and bipolar disorder.

    PubMed

    Cellard, Caroline; Rouleau, Nancie; Moreau, Isabel; Gilbert, Elsa; Paccalet, Thomas; Roy, Marc-André; Jomphe, Valérie; Mérette, Chantal; Maziade, Michel

    2015-09-30

    The developmental aspects of cognitive structures from childhood until adulthood and across different levels of risk for psychopathology have been little studied. The aim of the current study was to explore the cognitive factorial structure in subsamples from highly familial and densely affected kindreds of schizophrenia and bipolar disorder - i.e. affected adult members, non-affected adult members and high-risk youth. The same neuropsychological battery was administered in a sample of 480 participants: schizophrenia and bipolar patients (n=51), young high-risk offspring (n=61), non-affected adult relatives of patients (n=96), and controls (n=272). Exploratory Factorial Analysis was performed in the control sample and yielded a 5-factor solution: verbal comprehension, processing speed/working memory, visual learning and memory, verbal learning and memory, reasoning and problem solving. Confirmatory factor analysis indicated that the hierarchical 5-factor solution was well suited for the young high-risk offspring, the non-affected adult relatives of patient and the patients. A hierarchical model with a "g" factor was a good fit for all subsamples. These results suggest that cognitive impairments may aggregate in highly familial individuals. PMID:26233828

  18. An Analysis of Factors That Affect the Educational Performance of Agricultural Students

    ERIC Educational Resources Information Center

    Greenway, Gina

    2012-01-01

    Many factors contribute to student achievement. This study focuses on three areas: how students learn, how student personality type affects performance, and how course format affects performance outcomes. The analysis sought to improve understanding of the direction and magnitude with which each of these factors impacts student success. Improved…

  19. Responses to formal performance appraisal feedback: the role of negative affectivity.

    PubMed

    Lam, Simon S K; Yik, Michelle S M; Schaubroeck, John

    2002-02-01

    This study examined the effects of performance appraisal feedback on job and organizational attitudes of tellers (N = 329) in a large international bank. Negative affectivity moderated the link between favorable appraisal feedback and job attitudes. Among the higher rated performers, attitudes were improved 1 month after being notified of favorable appraisal results (Time 2). Improved attitudes persisted 6 months after the performance appraisal (Time 3) among tellers with low negative affectivity but not among those with high negative affectivity. Among the lower rated performers, mean levels of attitudes did not change significantly during the study. PMID:11924542

  20. The differential influences of positive affect, random reward, and performance-contingent reward on cognitive control.

    PubMed

    Fröber, Kerstin; Dreisbach, Gesine

    2014-06-01

    Growing evidence suggests that positive affect and reward have differential effects on cognitive control. So far, however, these effects have never been studied together. Here, the authors present one behavioral study investigating the influences of positive affect and reward (contingent and noncontingent) on proactive control. A modified version of the AX-continuous performance task, which has repeatedly been shown to be sensitive to reward and affect manipulations, was used. In a first phase, two experimental groups received either neutral or positive affective pictures before every trial. In a second phase, the two halves of a given affect group additionally received, respectively, performance-contingent or random rewards. The results replicated the typical affect effect, in terms of reduced proactive control under positive as compared to neutral affect. Also, the typical reward effects associated with increased proactive control were replicated. Most interestingly, performance-contingent reward counteracted the positive affect effect, whereas random reward mirrored that effect. In sum, this study provides first evidence that performance-contingent reward, on the one hand, and positive affect and performance-noncontingent reward, on the other hand, have oppositional effects on cognitive control: Only performance-contingent reward showed a motivational effect in terms of a strategy shift toward increased proactive control, whereas positive affect alone and performance-noncontingent reward reduced proactive control. Moreover, the integrative design of this study revealed the vulnerability of positive affect effects to motivational manipulations. The results are discussed with respect to current neuroscientific theories of the effects of dopamine on affect, reward, and cognitive control. PMID:24659000

  1. Identifying Affective Domains That Correlate and Predict Mathematics Performance in High-Performing Students in Singapore

    ERIC Educational Resources Information Center

    Lim, Siew Yee; Chapman, Elaine

    2015-01-01

    Past studies have shown that distinct yet highly correlated sub-constructs of three broad mathematics affective variables: (a) motivation, (b) attitudes and (c) anxiety, have varying degree of correlation with mathematics achievement. The sub-constructs of these three affective constructs are as follows: (a) (i) amotivation, (ii) external…

  2. Combined effects of positive and negative affectivity and job satisfaction on job performance and turnover intentions.

    PubMed

    Bouckenooghe, Dave; Raja, Usman; Butt, Arif Nazir

    2013-01-01

    Capturing data from employee-supervisor dyads (N = 321) from eight organizations in Pakistan, including human service organizations, an electronics assembly plant, a packaging material manufacturing company, and a small food processing plant, we used moderated regression analysis to examine whether the relationships between trait affect (positive affectivity [PA] and negative affectivity [NA]) and two key work outcome variables (job performance and turnover) are contingent upon the level of job satisfaction. We applied the Trait Activation Theory to explain the moderating effect of job satisfaction on the relationship between affect and performance and between affect and turnover. Overall, the data supported our hypotheses. Positive and negative affectivity influenced performance and the intention to quit, and job satisfaction moderated these relationships. We discuss in detail the results of these findings and their implications for research and practice. PMID:23469474

  3. STRUCTURAL PERFORMANCE OF DEGRADED REINFORCED CONCRETE MEMBERS.

    SciTech Connect

    Braverman, J.I.; Miller, C.A.; Ellingwood, B.R.; Naus, D.J.; Hofmayer, C.H.; Bezler, P.; Chang, T.Y.

    2001-03-22

    This paper describes the results of a study to evaluate, in probabilistic terms, the effects of age-related degradation on the structural performance of reinforced concrete members at nuclear power plants. The paper focuses on degradation of reinforced concrete flexural members and shear walls due to the loss of steel reinforcing area and loss of concrete area (cracking/spalling). Loss of steel area is typically caused by corrosion while cracking and spalling can be caused by corrosion of reinforcing steel, freeze-thaw, or aggressive chemical attack. Structural performance in the presence of uncertainties is depicted by a fragility (or conditional probability of failure). The effects of degradation on the fragility of reinforced concrete members are calculated to assess the potential significance of various levels of degradation. The fragility modeling procedures applied to degraded concrete members can be used to assess the effects of degradation on plant risk and can lead to the development of probability-based degradation acceptance limits.

  4. Combined loading criterial influence on structural performance

    NASA Technical Reports Server (NTRS)

    Kuchta, B. J.; Sealey, D. M.; Howell, L. J.

    1972-01-01

    An investigation was conducted to determine the influence of combined loading criteria on the space shuttle structural performance. The study consisted of four primary phases: Phase (1) The determination of the sensitivity of structural weight to various loading parameters associated with the space shuttle. Phase (2) The determination of the sensitivity of structural weight to various levels of loading parameter variability and probability. Phase (3) The determination of shuttle mission loading parameters variability and probability as a function of design evolution and the identification of those loading parameters where inadequate data exists. Phase (4) The determination of rational methods of combining both deterministic time varying and probabilistic loading parameters to provide realistic design criteria. The study results are presented.

  5. Daily fluctuations in positive affect positively co-vary with working memory performance.

    PubMed

    Brose, Annette; Lövdén, Martin; Schmiedek, Florian

    2014-02-01

    Positive affect is related to cognitive performance in multiple ways. It is associated with motivational aspects of performance, affective states capture attention, and information processing modes are a function of affect. In this study, we examined whether these links are relevant within individuals across time when they experience minor ups and downs of positive affect and work on cognitive tasks in the laboratory on a day-to-day basis. Using a microlongitudinal design, 101 younger adults (20-31 years of age) worked on 3 working memory tasks on about 100 occasions. Every day, they also reported on their momentary affect and their motivation to work on the tasks. In 2 of the 3 tasks, performance was enhanced on days when positive affect was above average. This performance enhancement was also associated with more motivation. Importantly, increases in task performance on days with above-average positive affect were mainly unrelated to variations in negative affect. This study's results are in line with between-person findings suggesting that high levels of well-being are associated with successful outcomes. They imply that success on cognitively demanding tasks is more likely on days when feeling happier. PMID:24364855

  6. Work-family enrichment and job performance: a constructive replication of affective events theory.

    PubMed

    Carlson, Dawn; Kacmar, K Michele; Zivnuska, Suzanne; Ferguson, Merideth; Whitten, Dwayne

    2011-07-01

    Based on affective events theory (AET), we hypothesize a four-step model of the mediating mechanisms of positive mood and job satisfaction in the relationship between work-family enrichment and job performance. We test this model for both directions of enrichment (work-to-family and family-to-work). We used two samples to test the model using structural equation modeling. Results from Study 1, which included 240 full-time employees, were replicated in Study 2, which included 189 matched subordinate-supervisor dyads. For the work-to-family direction, results from both samples support our conceptual model and indicate mediation of the enrichment-performance relationship for the work-to-family direction of enrichment. For the family-to-work direction, results from the first sample support our conceptual model but results from the second sample do not. Our findings help elucidate mixed findings in the enrichment and job performance literatures and contribute to an understanding of the mechanisms linking these concepts. We conclude with a discussion of the practical and theoretical implications of our findings. PMID:21728437

  7. How Knowledge Management Is Affected by Organizational Structure

    ERIC Educational Resources Information Center

    Mahmoudsalehi, Mehdi; Moradkhannejad, Roya; Safari, Khalil

    2012-01-01

    Purpose: Identifying the impact of organizational structure on knowledge management (KM) is the aim of this study, as well as recognizing the importance of each variable indicator in creating, sharing and utility of knowledge. Design/methodology/approach: For understanding relationships between the main variables (organizational structure-KM), the…

  8. Retail pharmacy market structure and performance.

    PubMed

    Brooks, John M; Doucette, William R; Wan, Shaowei; Klepser, Donald G

    2008-01-01

    Substantial variation has been observed in the use of prescription drugs from retail pharmacies, the level of services provided by retail pharmacies, and the prices paid for prescriptions from retail pharmacies. It is not clear whether local area retail pharmacy market structures affect these pharmacy outcomes. The goal of this paper is to discuss the potential research avenues to address these issues. The discussion provides. 1) background on the retail pharmacy and its place within the pharmaceutical supply chain; 2) a discussion of the data that are available to address these issues and the measures that can be developed from these data; and 3) a review of existing research findings and gaps in knowledge. PMID:18524293

  9. Analysis of factors affecting satisfaction level on problem based learning approach using structural equation modeling

    NASA Astrophysics Data System (ADS)

    Hussain, Nur Farahin Mee; Zahid, Zalina

    2014-12-01

    Nowadays, in the job market demand, graduates are expected not only to have higher performance in academic but they must also be excellent in soft skill. Problem-Based Learning (PBL) has a number of distinct advantages as a learning method as it can deliver graduates that will be highly prized by industry. This study attempts to determine the satisfaction level of engineering students on the PBL Approach and to evaluate their determinant factors. The Structural Equation Modeling (SEM) was used to investigate how the factors of Good Teaching Scale, Clear Goals, Student Assessment and Levels of Workload affected the student satisfaction towards PBL approach.

  10. Leveraging Structure to Improve Classification Performance in Sparsely Labeled Networks

    SciTech Connect

    Gallagher, B; Eliassi-Rad, T

    2007-10-22

    We address the problem of classification in a partially labeled network (a.k.a. within-network classification), with an emphasis on tasks in which we have very few labeled instances to start with. Recent work has demonstrated the utility of collective classification (i.e., simultaneous inferences over class labels of related instances) in this general problem setting. However, the performance of collective classification algorithms can be adversely affected by the sparseness of labels in real-world networks. We show that on several real-world data sets, collective classification appears to offer little advantage in general and hurts performance in the worst cases. In this paper, we explore a complimentary approach to within-network classification that takes advantage of network structure. Our approach is motivated by the observation that real-world networks often provide a great deal more structural information than attribute information (e.g., class labels). Through experiments on supervised and semi-supervised classifiers of network data, we demonstrate that a small number of structural features can lead to consistent and sometimes dramatic improvements in classification performance. We also examine the relative utility of individual structural features and show that, in many cases, it is a combination of both local and global network structure that is most informative.

  11. Using a False Biofeedback Methodology to Explore Relationships between Learners' Affect, Metacognition, and Performance

    ERIC Educational Resources Information Center

    Strain, Amber Chauncey; Azevedo, Roger; D'Mello, Sidney K.

    2013-01-01

    We used a false-biofeedback methodology to manipulate physiological arousal in order to induce affective states that would influence learners' metacognitive judgments and learning performance. False-biofeedback is a method used to induce physiological arousal (and resultant affective states) by presenting learners with audio stimuli of false heart…

  12. Performance-Based Occupational Affective Behavior Analysis (OABA). Implementation and Supporting Research.

    ERIC Educational Resources Information Center

    Pucel, David J.; And Others

    This document contains two sections: implementation of the performance-based Occupational Affective Behavior Analysis (OABA), and supporting research. Section 1 presents OABA, an analytic procedure designed to identify those affective behaviors important to success in an occupation, and gives directions on how to implement the procedure. The…

  13. Investigating Learner Affective Performance in Web-Based Learning by Using Entrepreneurship as a Metaphor

    ERIC Educational Resources Information Center

    Liu, Ming-Chou; Chi, Ming-Hsiao

    2012-01-01

    In the era of the Internet, factors which influence effective learning in a Web-based learning environment are well worth exploring. In addition to knowledge acquisition and skills training, affect is also an important factor, since successful learning requires excellent affective performance. Thus this study focuses on learners' affective…

  14. To branch out or stay focused? Affective shifts differentially predict organizational citizenship behavior and task performance.

    PubMed

    Yang, Liu-Qin; Simon, Lauren S; Wang, Lei; Zheng, Xiaoming

    2016-06-01

    We draw from personality systems interaction (PSI) theory (Kuhl, 2000) and regulatory focus theory (Higgins, 1997) to examine how dynamic positive and negative affective processes interact to predict both task and contextual performance. Using a twice-daily diary design over the course of a 3-week period, results from multilevel regression analysis revealed that distinct patterns of change in positive and negative affect optimally predicted contextual and task performance among a sample of 71 employees at a medium-sized technology company. Specifically, within persons, increases (upshifts) in positive affect over the course of a workday better predicted the subsequent day's organizational citizenship behavior (OCB) when such increases were coupled with decreases (downshifts) in negative affect. The optimal pattern of change in positive and negative affect differed, however, in predicting task performance. That is, upshifts in positive affect over the course of the workday better predicted the subsequent day's task performance when such upshifts were accompanied by upshifts in negative affect. The contribution of our findings to PSI theory and the broader affective and motivation regulation literatures, along with practical implications, are discussed. (PsycINFO Database Record PMID:26882443

  15. Psychological Factor Affecting English Speaking Performance for the English Learners in Indonesia

    ERIC Educational Resources Information Center

    Haidara, Youssouf

    2016-01-01

    In every learning situation or environment, human psychology plays a significant role. English speaking is a language skill that is highly affected by human psychology. This research aimed at describing the psychological factor that affects negatively the English speaking performance for the English learners in Indonesia. A descriptive qualitative…

  16. Affect, Curiosity, and Socialization-Related Learning: A Path Analysis of Antecedents to Job Performance.

    ERIC Educational Resources Information Center

    Reio, Thomas G.; Callahan, Jamie L.

    Affect, curiosity, and socialization-relation were explored as potential mediators of the relationship between both state and trait affect and job performance. The cross-sectional sample consisted of 81 women and 152 men between the ages of 17 and 50 or older. The typical participant was a male Caucasian under the age of 40 with some college…

  17. Job Satisfaction and Performance: The Moderating Effects of Value Attainment and Affective Disposition.

    ERIC Educational Resources Information Center

    Hochwarter, Wayne A.; Perrewe, Pamela L.; Ferris, Gerald R.; Brymer, Robert A.

    1999-01-01

    A study of 270 hotel managers found that the strongest positive relationship between job satisfaction and performance occurred when high attainment of values associated with work was coupled with high-positive or low-negative affective disposition. (SK)

  18. Subjective cognitive complaints, affective distress, and objective cognitive performance in Persian Gulf War veterans.

    PubMed

    Binder, L M; Storzbach, D; Anger, W K; Campbell, K A; Rohlman, D S; of the Portland Environmental, O M; Center, H R

    1999-08-01

    We examined subjective cognitive complaints, affective distress, and cognitive performance in Persian Gulf veterans who reported illness and cognitive complaints. We predicted a stronger relationship between subjective cognitive complaints and affective distress than between subjective cognitive complaints and objective cognitive performance. This prediction was confirmed in a sample of 100 veterans. The results suggest that cognitive impairment should not be diagnosed in this population without objective confirmation with cognitive testing. PMID:14590580

  19. Structural Design Strategies for Improved Small Overlap Crashworthiness Performance.

    PubMed

    Mueller, Becky C; Brethwaite, Andrew S; Zuby, David S; Nolan, Joseph M

    2014-11-01

    In 2012, the Insurance Institute for Highway Safety (IIHS) began a 64 km/h small overlap frontal crash test consumer information test program. Thirteen automakers already have redesigned models to improve test performance. One or more distinct strategies are evident in these redesigns: reinforcement of the occupant compartment, use of energy-absorbing fender structures, and the addition of engagement structures to induce vehicle lateral translation. Each strategy influences vehicle kinematics, posing additional challenges for the restraint systems. The objective of this two-part study was to examine how vehicles were modified to improve small overlap test performance and then to examine how these modifications affect dummy response and restraint system performance. Among eight models tested before and after design changes, occupant compartment intrusion reductions ranged from 6 cm to 45 cm, with the highest reductions observed in models with the largest number of modifications. All redesigns included additional occupant compartment reinforcement, one-third added structures to engage the barrier, and two modified a shotgun load path. Designs with engagement structures produced greater glance-off from the barrier and exhibited lower delta Vs but experienced more lateral outboard motion of the dummy. Designs with heavy reinforcement of the occupant compartment had higher vehicle accelerations and delta V. In three cases, these apparent trade-offs were not well addressed by concurrent changes in restraint systems and resulted in increased injury risk compared with the original tests. Among the 36 models tested after design changes, the extent of design changes correlated to structural performance. Half of the vehicles with the lowest intrusion levels incorporated aspects of all three design strategies. Vehicle kinematics and dummy and restraint system characteristics were similar to those observed in the before/after pairs. Different combinations of structural

  20. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof.

    PubMed

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%-26% volumetric moisture content) and temperature (21°C-36°C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  1. Can microcystins affect zooplankton structure community in tropical eutrophic reservoirs?

    PubMed

    Paes, T A S V; Costa, I A S; Silva, A P C; Eskinazi-Sant'Anna, E M

    2016-06-01

    The aim of our study was to assess whether cyanotoxins (microcystins) can affect the composition of the zooplankton community, leading to domination of microzooplankton forms (protozoans and rotifers). Temporal variations in concentrations of microcystins and zooplankton biomass were analyzed in three eutrophic reservoirs in the semi-arid northeast region of Brazil. The concentration of microcystins in water proved to be correlated with the cyanobacterial biovolume, indicating the contributions from colonial forms such as Microcystis in the production of cyanotoxins. At the community level, the total biomass of zooplankton was not correlated with the concentration of microcystin (r2 = 0.00; P > 0.001), but in a population-level analysis, the biomass of rotifers and cladocerans showed a weak positive correlation. Cyclopoid copepods, which are considered to be relatively inefficient in ingesting cyanobacteria, were negatively correlated (r2 = - 0.01; P > 0.01) with the concentration of cyanotoxins. Surprisingly, the biomass of calanoid copepods was positively correlated with the microcystin concentration (r2 = 0.44; P > 0.001). The results indicate that allelopathic control mechanisms (negative effects of microcystin on zooplankton biomass) do not seem to substantially affect the composition of mesozooplankton, which showed a constant and high biomass compared to the microzooplankton (rotifers). These results may be important to better understand the trophic interactions between zooplankton and cyanobacteria and the potential effects of allelopathic compounds on zooplankton. PMID:26959954

  2. How Molecular Structure Affects Mechanical Properties of an Advanced Polymer

    NASA Technical Reports Server (NTRS)

    Nicholson, Lee M.; Whitley, Karen S.; Gates, Thomas S.; Hinkley, Jeffrey A.

    2000-01-01

    density was performed over a range of temperatures below the glass transition temperature. The physical characterization, elastic properties and notched tensile strength all as a function of molecular weight and test temperature were determined. For the uncrosslinked SI material, it was shown that notched tensile strength is a strong function of both temperature and molecular weight, whereas stiffness is only a strong function of temperature. For the crosslinked PETI-SI material, it was shown that the effect of crosslinking significantly enhances the mechanical performance of the low molecular weight material; comparable to that exhibited by the high molecular weight material.

  3. Effects of Developmental Changes in Affective Meaning Structure on Memory.

    ERIC Educational Resources Information Center

    Ghatala, Elizabeth S.; And Others

    In an incidental memory task, second, sixth, and tenth-grade students performed three orientating tasks on different subsets of items in a list of common nouns. In one condition (EPA), children judged words on the Evaluative, Potency and Activity dimensions of the semantic differential. In another condition (EEE) children made phonetic judgments.…

  4. Stage structure alters how complexity affects stability of ecological networks

    USGS Publications Warehouse

    Rudolf, V.H.W.; Lafferty, Kevin D.

    2011-01-01

    Resolving how complexity affects stability of natural communities is of key importance for predicting the consequences of biodiversity loss. Central to previous stability analysis has been the assumption that the resources of a consumer are substitutable. However, during their development, most species change diets; for instance, adults often use different resources than larvae or juveniles. Here, we show that such ontogenetic niche shifts are common in real ecological networks and that consideration of these shifts can alter which species are predicted to be at risk of extinction. Furthermore, niche shifts reduce and can even reverse the otherwise stabilizing effect of complexity. This pattern arises because species with several specialized life stages appear to be generalists at the species level but act as sequential specialists that are hypersensitive to resource loss. These results suggest that natural communities are more vulnerable to biodiversity loss than indicated by previous analyses.

  5. Performance Assessment in CTE: Focusing on the Cognitive, Psychomotor ...and Affective Domains

    ERIC Educational Resources Information Center

    Washer, Bart; Cochran, Lori

    2012-01-01

    When a student is performing in the psychomotor domain, the authors believe the student is also performing in the cognitive domain (sequencing steps, evaluating the situation) and in the affective domain (appreciating a job well done, quality control, safety). As Dabney Doty, former instructor at the University of Central Missouri, stated, "There…

  6. The Developmental Dynamics of Children's Academic Performance and Mothers' Homework-Related Affect and Practices

    ERIC Educational Resources Information Center

    Silinskas, Gintautas; Kiuru, Noona; Aunola, Kaisa; Lerkkanen, Marja-Kristiina; Nurmi, Jari-Erik

    2015-01-01

    This study investigated the longitudinal associations between children's academic performance and their mothers' affect, practices, and perceptions of their children in homework situations. The children's (n = 2,261) performance in reading and math was tested in Grade 1 and Grade 4, and the mothers (n = 1,476) filled out questionnaires on their…

  7. Centrality and Charisma: Comparing How Leader Networks "and" Attributions Affect Team Performance

    ERIC Educational Resources Information Center

    Balkundi, Prasad; Kilduff, Martin; Harrison, David A.

    2011-01-01

    When leaders interact in teams with their subordinates, they build social capital that can have positive effects on team performance. Does this social capital affect team performance because subordinates come to see the leader as charismatic? We answered this question by examining 2 models. First, we tested the charisma-to-centrality model…

  8. Some Factors That Affecting the Performance of Mathematics Teachers in Junior High School in Medan

    ERIC Educational Resources Information Center

    Manullang, Martua; Rajagukguk, Waminton

    2016-01-01

    Some Factor's That Affecting The Mathematic Teacher Performance For Junior High School In Medan. This research will examine the effect of direct and indirect of the Organizational Knowledge towards the achievement motivation, decision making, organizational commitment, the performance of mathematics teacher. The research method is a method of…

  9. The developmental dynamics of children's academic performance and mothers' homework-related affect and practices.

    PubMed

    Silinskas, Gintautas; Kiuru, Noona; Aunola, Kaisa; Lerkkanen, Marja-Kristiina; Nurmi, Jari-Erik

    2015-04-01

    This study investigated the longitudinal associations between children's academic performance and their mothers' affect, practices, and perceptions of their children in homework situations. The children's (n = 2,261) performance in reading and math was tested in Grade 1 and Grade 4, and the mothers (n = 1,476) filled out questionnaires on their affect, practices, and perceptions while their children were in Grades 2, 3, and 4. The results showed, first, that the more help in homework the mothers reported, the slower was the development of their children's academic performance from Grade 1 to Grade 4. This negative association was true especially if mothers perceived their children not to be able to work autonomously. Second, children's good academic performance in Grade 1 predicted mothers' perception of child's ability to be autonomous and positive affect in homework situations later on, whereas poor performance predicted mothers' negative affect, help, and monitoring. Finally, mothers' negative affect mediated the association between children's poor performance, maternal practices, and perceptions of their children. PMID:25798959

  10. Cyanobacteria Affect Fitness and Genetic Structure of Experimental Daphnia Populations.

    PubMed

    Drugă, Bogdan; Turko, Patrick; Spaak, Piet; Pomati, Francesco

    2016-04-01

    Zooplankton communities can be strongly affected by cyanobacterial blooms, especially species of genus Daphnia, which are key-species in lake ecosystems. Here, we explored the effect of microcystin/nonmicrocystin (MC/non-MC) producing cyanobacteria in the diet of experimental Daphnia galeata populations composed of eight genotypes. We used D. galeata clones hatched from ephippia 10 to 60 years old, which were first tested in monocultures, and then exposed for 10 weeks as mixed populations to three food treatments consisting of green algae combined with cyanobacteria able/unable of producing MC. We measured the expression of nine genes potentially involved in Daphnia acclimation to cyanobacteria: six protease genes, one ubiquitin-conjugating enzyme gene, and two rRNA genes, and then we tracked the dynamics of the genotypes in mixed populations. The expression pattern of one protease and the ubiquitin-conjugating enzyme genes was positively correlated with the increased fitness of competing clones in the presence of cyanobacteria, suggesting physiological plasticity. The genotype dynamics in mixed populations was only partially related to the growth rates of clones in monocultures and varied strongly with the food. Our results revealed strong intraspecific differences in the tolerance of D. galeata clones to MC/non-MC-producing cyanobacteria in their diet, suggesting microevolutionary effects. PMID:26943751

  11. Size, but not experience, affects the ontogeny of constriction performance in ball pythons (Python regius).

    PubMed

    Penning, David A; Dartez, Schuyler F

    2016-03-01

    Constriction is a prey-immobilization technique used by many snakes and is hypothesized to have been important to the evolution and diversification of snakes. However, very few studies have examined the factors that affect constriction performance. We investigated constriction performance in ball pythons (Python regius) by evaluating how peak constriction pressure is affected by snake size, sex, and experience. In one experiment, we tested the ontogenetic scaling of constriction performance and found that snake diameter was the only significant factor determining peak constriction pressure. The number of loops applied in a coil and its interaction with snake diameter did not significantly affect constriction performance. Constriction performance in ball pythons scaled differently than in other snakes that have been studied, and medium to large ball pythons are capable of exerting significantly higher pressures than those shown to cause circulatory arrest in prey. In a second experiment, we tested the effects of experience on constriction performance in hatchling ball pythons over 10 feeding events. By allowing snakes in one test group to gain constriction experience, and manually feeding snakes under sedation in another test group, we showed that experience did not affect constriction performance. During their final (10th) feedings, all pythons constricted similarly and with sufficiently high pressures to kill prey rapidly. At the end of the 10 feeding trials, snakes that were allowed to constrict were significantly smaller than their non-constricting counterparts. J. Exp. Zool. 9999A:XX-XX, 2016. © 2016 Wiley Periodicals, Inc. PMID:26847931

  12. Earthworm ecology affects the population structure of their Verminephrobacter symbionts.

    PubMed

    Viana, Flávia; Jensen, Christopher Erik; Macey, Michael; Schramm, Andreas; Lund, Marie Braad

    2016-05-01

    Earthworms carry species-specific Verminephrobacter symbionts in their nephridia (excretory organs). The symbionts are vertically transmitted via the cocoon, can only colonize the host during early embryonic development, and have co-speciated with their host for about 100 million years. Although several studies have addressed Verminephrobacter diversity between worm species, the intra-species diversity of the symbiont population has never been investigated. In this study, symbiont population structure was examined by using a multi-locus sequence typing (MLST) approach on Verminephrobacter isolated from two contrasting ecological types of earthworm hosts: the high population density, fast reproducing compost worms, Eisenia andrei and Eisenia fetida, and the low-density, slow reproducing Aporrectodea tuberculata, commonly found in garden soils. Three distinct populations were investigated for both types and, according to MLST analysis of 193 Verminephrobacter isolates, the symbiont community in each worm individual was very homogeneous. The more solitary A. tuberculata carried unique symbiont populations in 9 out of 10 host individuals, whereas the symbiont populations in the social compost worms were homogeneous across host individuals from the same population. These data suggested that host ecology shaped the population structure of Verminephrobacter symbionts. The homogeneous symbiont populations in the compost worms led to the hypothesis that Verminephrobacter could be transferred bi-parentally or via leaky horizontal transmission in high-density, frequently mating worm populations. PMID:27040820

  13. Does small scale structure significantly affect cosmological dynamics?

    PubMed

    Adamek, Julian; Clarkson, Chris; Durrer, Ruth; Kunz, Martin

    2015-02-01

    The large-scale homogeneity and isotropy of the Universe is generally thought to imply a well-defined background cosmological model. It may not. Smoothing over structure adds in an extra contribution, transferring power from small scales up to large. Second-order perturbation theory implies that the effect is small, but suggests that formally the perturbation series may not converge. The amplitude of the effect is actually determined by the ratio of the Hubble scales at matter-radiation equality and today-which are entirely unrelated. This implies that a universe with significantly lower temperature today could have significant backreaction from more power on small scales, and so provides the ideal testing ground for understanding backreaction. We investigate this using two different N-body numerical simulations-a 3D Newtonian and a 1D simulation which includes all relevant relativistic effects. We show that while perturbation theory predicts an increasing backreaction as more initial small-scale power is added, in fact the virialization of structure saturates the backreaction effect at the same level independently of the equality scale. This implies that backreaction is a small effect independently of initial conditions. Nevertheless, it may still contribute at the percent level to certain cosmological observables and therefore it cannot be neglected in precision cosmology. PMID:25699430

  14. OPERATIONAL AND COMPOSITIONAL FACTORS THAT AFFECT THE PERFORMANCE PROPERTIES OF ARP/MCU SALTSTONE GROUT

    SciTech Connect

    Reigel, M.; Edwards, T.; Pickenheim, B.

    2012-02-15

    The Saltstone Production Facility (SPF) receives low level waste (LLW) salt solution from Tank 50H for treatment and disposal. Tank 50H receives transfers from the Effluent Treatment Project (ETP), the H-Canyon General Purpose Evaporator, and the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) Decontaminated Salt Solution Hold Tank (DSS-HT). At the SPF, the LLW is mixed with premix (a cementitious mixture of portland cement (PC), blast furnace slag (BFS) and Class F fly ash (FA)) in a Readco mixer to produce fresh (uncured) saltstone that is transferred to the Saltstone Disposal Facility (SDF) vaults. The saltstone formulation (mix design) must produce a grout waste form that meets both placement and performance properties. In previous simulated saltstone studies, multiple compositional factors were identified that drive the performance properties of saltstone made from the projected ARP/MCU salt solution. This composition was selected as salt solution simulant since ARP/MCU is the primary influent into Tank 50H. The primary performance property investigated was hydraulic conductivity since it is a variable input property to the saltstone Performance Assessment (PA) transport model. In addition, the porosity, also referred to as void structure, is another variable that impacts the PA response. In addition, Young's modulus and cured density are other performance properties analyzed in this report; however they are indicators of the performance of saltstone and not direct inputs into the PA. The data from previous studies showed that the largest impact on the performance properties of saltstone was due to curing temperature, followed by aluminate concentration in the salt solution, water to premix ratio and premix composition. However, due to the scope of the previous studies, only a few mixes were cured and analyzed at higher temperatures. The samples cured at 60 C had an increased hydraulic conductivity of approximately 600 times

  15. Elasticity of vesicles affects hairless mouse skin structure and permeability.

    PubMed

    van den Bergh, B A; Bouwstra, J A; Junginger, H E; Wertz, P W

    1999-12-01

    One of the possibilities for increasing the penetration rate of drugs through the skin is the use of vesicular systems. Currently, special attention is paid to the elastic properties of liquid-state vesicles, which are supposed to have superior properties compared to gel-state vesicles with respect to skin interactions. In this study, the effects of vesicles on hairless mouse skin, both in vivo and in vitro, were studied in relation to the composition of vesicles. The interactions of elastic vesicles containing the single chain surfactant octaoxyethylene laurate-ester (PEG-8-L) and sucrose laurate-ester (L-595) with hairless mouse skin were studied, in vivo, after non-occlusive application for 1, 3 and 6 h. The skin ultrastructure was examined by ruthenium tetroxide electron microscopy (TEM) and histology. The extent, to which vesicle constituents penetrated into the stratum corneum, was quantified by thin layer chromatography (TLC). The interactions of the elastic vesicles containing PEG-8-L and L-595 surfactants were compared with those observed after treatment with rigid vesicles containing the surfactant sucrose stearate-ester (Wasag-7). Furthermore, skin permeability experiments were carried out to investigate the effect of treatment with PEG-8-L micelles, elastic vesicles (containing PEG-8-L and L-595 surfactants) or rigid Wasag-7 vesicles on the 3H(2)O transport through hairless mouse skin, in vitro, after non-occlusive application. Treatment of hairless mouse skin with the elastic vesicles affected the ultrastructure of the stratum corneum: distinct regions with lamellar stacks derived from the vesicles were observed in intercellular spaces of the stratum corneum. These stacks disrupted the organization of skin bilayers leading to an increased skin permeability, whereas no changes in the ultrastructure of the underlying viable epidermis were observed. Treatment with rigid Wasag-7 vesicles did not affect the skin ultrastructure or skin permeability. TLC

  16. Structure-mechanical function relations at nano-scale in heat-affected human dental tissue.

    PubMed

    Sui, Tan; Sandholzer, Michael A; Le Bourhis, Eric; Baimpas, Nikolaos; Landini, Gabriel; Korsunsky, Alexander M

    2014-04-01

    The knowledge of the mechanical properties of dental materials related to their hierarchical structure is essential for understanding and predicting the effect of microstructural alterations on the performance of dental tissues in the context of forensic and archaeological investigation as well as laser irradiation treatment of caries. So far, few studies have focused on the nano-scale structure-mechanical function relations of human teeth altered by chemical or thermal treatment. The response of dental tissues to thermal treatment is thought to be strongly affected by the mineral crystallite size, their spatial arrangement and preferred orientation. In this study, synchrotron-based small and wide angle X-ray scattering (SAXS/WAXS) techniques were used to investigate the micro-structural alterations (mean crystalline thickness, crystal perfection and degree of alignment) of heat-affected dentine and enamel in human dental teeth. Additionally, nanoindentation mapping was applied to detect the spatial and temperature-dependent nano-mechanical properties variation. The SAXS/WAXS results revealed that the mean crystalline thickness distribution in dentine was more uniform compared with that in enamel. Although in general the mean crystalline thickness increased both in dentine and enamel as the temperature increased, the local structural variations gradually reduced. Meanwhile, the hardness and reduced modulus in enamel decreased as the temperature increased, while for dentine, the tendency reversed at high temperature. The analysis of the correlation between the ultrastructure and mechanical properties coupled with the effect of temperature demonstrates the effect of mean thickness and orientation on the local variation of mechanical property. This structural-mechanical property alteration is likely to be due to changes of HAp crystallites, thus dentine and enamel exhibit different responses at different temperatures. Our results enable an improved understanding of

  17. Maternal affection moderates the impact of psychological control on a child's mathematical performance.

    PubMed

    Aunola, Kaisa; Nurmi, Jari-Erik

    2004-11-01

    This study investigated the extent to which mothers' psychological control predicts their children's mathematical performance during the children's transition from preschool to primary school over and above the impact of maternal affection and behavioral control. Also investigated was the extent to which maternal affection and behavioral control moderate the impact of mothers' psychological control. Children 5-6 years old at baseline (N=196) were followed up 6 times to measure their performance in mathematics over a 3-year period from preschool to 2nd grade. Mothers were asked to fill in a questionnaire measuring their parenting styles once every year over the 3-year period. A high level of psychological control exercised by mothers predicted their children's slow progress in mathematics. However, this impact was particularly evident among those children whose mothers reported a high level of affection. No evidence was found that children's mathematical performance had any effect on their mothers' parenting styles. PMID:15535751

  18. Microhabitat use affects brain size and structure in intertidal gobies.

    PubMed

    White, Gemma E; Brown, Culum

    2015-01-01

    The ecological cognition hypothesis poses that the brains and behaviours of individuals are largely shaped by the environments in which they live and the associated challenges they must overcome during their lives. Here we examine the effect of environmental complexity on relative brain size in 4 species of intertidal gobies from differing habitats. Two species were rock pool specialists that lived on spatially complex rocky shores, while the remainder lived on dynamic, but structurally simple, sandy shores. We found that rock pool-dwelling species had relatively larger brains and telencephalons in particular, while sand-dwelling species had a larger optic tectum and hypothalamus. In general, it appears that various fish species trade off neural investment in specific brain lobes depending on the environment in which they live. Our previous research suggests that rock pool species have greater spatial learning abilities, enabling them to navigate their spatially complex environment, which may account for their enlarged telencephalon, while sand-dwelling species likely have a reduced need for spatial learning, due to their spatially simple habitat, and a greater need for visual acuity. The dorsal medulla and cerebellum size was unaffected by the habitat in which the fish lived, but there were differences between species indicative of species-specific trade-offs in neural investment. PMID:25896449

  19. A review of published quantitative experimental studies on factors affecting laboratory fume hood performance.

    PubMed

    Ahn, Kwangseog; Woskie, Susan; DiBerardinis, Louis; Ellenbecker, Michael

    2008-11-01

    This study attempted to identify the important factors that affect the performance of a laboratory fume hood and the relationship between the factors and hood performance under various conditions by analyzing and generalizing the results from other studies that quantitatively investigated fume hood performance. A literature search identified 43 studies that were published from 1966 to 2006. For each of those studies, information on the type of test methods used, the factors investigated, and the findings were recorded and summarized. Among the 43 quantitative experimental studies, 21 comparable studies were selected, and then a meta-analysis of the comparable studies was conducted. The exposure concentration variable from the resulting 617 independent test conditions was dichotomized into acceptable or unacceptable using the control level of 0.1 ppm tracer gas. Regression analysis using Cox proportional hazards models provided hood failure ratios for potential exposure determinants. The variables that were found to be statistically significant were the presence of a mannequin/human subject, the distance between a source and breathing zone, and the height of sash opening. In summary, performance of laboratory fume hoods was affected mainly by the presence of a mannequin/human subject, distance between a source and breathing zone, and height of sash opening. Presence of a mannequin/human subject in front of the hood adversely affects hood performance. Worker exposures to air contaminants can be greatly reduced by increasing the distance between the contaminant source and breathing zone and by reducing the height of sash opening. Many other factors can also affect hood performance. Checking face velocity by itself is unlikely to be sufficient in evaluating hood performance properly. An evaluation of the performance of a laboratory fume hood should be performed with a human subject or a mannequin in front of the hood and should address the effects of the activities

  20. On the role of positive and negative affectivity in job performance: a meta-analytic investigation.

    PubMed

    Kaplan, Seth; Bradley, Jill C; Luchman, Joseph N; Haynes, Douglas

    2009-01-01

    Although interest regarding the role of dispositional affect in job behaviors has surged in recent years, the true magnitude of affectivity's influence remains unknown. To address this issue, the authors conducted a qualitative and quantitative review of the relationships between positive and negative affectivity (PA and NA, respectively) and various performance dimensions. A series of meta-analyses based on 57 primary studies indicated that PA and NA predicted task performance in the hypothesized directions and that the relationships were strongest for subjectively rated versus objectively rated performance. In addition, PA was related to organizational citizenship behaviors but not withdrawal behaviors, and NA was related to organizational citizenship behaviors, withdrawal behaviors, counterproductive work behaviors, and occupational injury. Mediational analyses revealed that affect operated through different mechanisms in influencing the various performance dimensions. Regression analyses documented that PA and NA uniquely predicted task performance but that extraversion and neuroticism did not, when the four were considered simultaneously. Discussion focuses on the theoretical and practical implications of these findings. (PsycINFO Database Record (c) 2009 APA, all rights reserved). PMID:19186902

  1. Dioecy, more than monoecy, affects plant spatial genetic structure: the case study of Ficus

    PubMed Central

    Nazareno, Alison G; Alzate-Marin, Ana L; Pereira, Rodrigo Augusto S

    2013-01-01

    In this analysis, we attempt to understand how monoecy and dioecy drive spatial genetic structure (SGS) in plant populations. For this purpose, plants of the genus Ficus were used as a comparative model due to their particular characteristics, including high species diversity, variation in life histories, and sexual systems. One of the main issues we assessed is whether dioecious fig tree populations are more spatially genetically structured than monoecious populations. Using the Sp statistic, which allows for quantitative comparisons among different studies, we compared the extent of SGS between monoecious and dioecious Ficus species. To broaden our conclusions we used published data on an additional 27 monoecious and dioecious plant species. Furthermore, genetic diversity analyses were performed for two monoecious Ficus species using 12 microsatellite markers in order to strengthen our conclusions about SGS. Our results show that dioecy, more than monoecy, significantly contributes to SGS in plant populations. On average, the estimate of Sp was six times higher for dioecious Ficus species than monoecious Ficus species and it was two times higher in dioecious than monoecious plant species. Considering these results, we emphasize that the long-distance pollen dispersal mechanism in monoecious Ficus species seems to be the dominant factor in determining weak spatial genetic structure, high levels of genetic diversity, and lack of inbreeding. Although Ficus constitute a model species to study SGS, a more general comparison encompassing a wider range of plants is required in order to better understand how sexual systems affect genetic structure. PMID:24223285

  2. Artefacts and biases affecting the evaluation of scoring functions on decoy sets for protein structure prediction

    PubMed Central

    Handl, Julia; Knowles, Joshua; Lovell, Simon C.

    2009-01-01

    Motivation: Decoy datasets, consisting of a solved protein structure and numerous alternative native-like structures, are in common use for the evaluation of scoring functions in protein structure prediction. Several pitfalls with the use of these datasets have been identified in the literature, as well as useful guidelines for generating more effective decoy datasets. We contribute to this ongoing discussion an empirical assessment of several decoy datasets commonly used in experimental studies. Results: We find that artefacts and sampling issues in the large majority of these data make it trivial to discriminate the native structure. This underlines that evaluation based on the rank/z-score of the native is a weak test of scoring function performance. Moreover, sampling biases present in the way decoy sets are generated or used can strongly affect other types of evaluation measures such as the correlation between score and root mean squared deviation (RMSD) to the native. We demonstrate how, depending on type of bias and evaluation context, sampling biases may lead to both over- or under-estimation of the quality of scoring terms, functions or methods. Availability: Links to the software and data used in this study are available at http://dbkgroup.org/handl/decoy_sets. Contact: simon.lovell@manchester.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:19297350

  3. Malaysian and Singaporean students' affective characteristics and mathematics performance: evidence from PISA 2012.

    PubMed

    Thien, Lei Mee; Ong, Mei Yean

    2015-01-01

    This paper attempts to identify the extent to which the affective characteristics of Malaysian and Singaporean students' attainment compared to the OECD average in Programme for International Student Assessment (PISA) 2012, and examine the influence of students' affective characteristics, gender, and their socioeconomic status on mathematics performance at both student and school levels. Sample consisted of 5197 and 5546 15-year-old Malaysian and Singaporean students. Data were analysed using hierarchical linear modelling approach with HLM 7.0 software. Results showed that the Index of economic, social, and cultural status (ESCS), mathematics self-efficacy, and mathematics anxiety have significant effects on mathematics performance in Malaysia and Singapore at the student level. Proportion of boys at the school level has no significant effects on mathematics performance for both Malaysian and Singaporean students. ESCS mean at the school level has positive and significant effects on mathematics performance in Malaysia, but not in Singapore. Limitations, implications, and future studies were discussed. PMID:26543698

  4. Impact of fMRI Scanner Noise on Affective State and Attentional Performance

    PubMed Central

    Jacob, Shawna N.; Shear, Paula K.; Norris, Matthew; Smith, Matthew; Osterhage, Jeff; Strakowski, Stephen M.; Cerullo, Michael; Fleck, David E.; Lee, Jing-Huei; Eliassen, James C.

    2015-01-01

    Introduction Previous research has shown that performance on cognitive tasks administered in the scanner can be altered by the scanner environment. There are no previous studies that have investigated the impact of scanner noise using a well-validated measure of affective change. The goal of this study was to determine whether performance on an affective attentional task or emotional response to the task would change in the presence of distracting acoustic noise, such as that encountered in an MRI environment. Method Thirty-four young adults with no self-reported history of neurologic disorder or mental illness completed three blocks of the affective Posner task outside of the scanner. The task was meant to induce frustration through monetary contingencies and rigged feedback. Participants completed a self-assessment manikin at the end of each block to rate their mood, arousal level, and sense of dominance. During the task, half of the participants heard noise (recorded from a 4T MRI system), and half heard no noise. Results The affective Posner task led to significant reductions in mood and increases in arousal in healthy participants. The presence of scanner noise did not impact task performance; however, individuals in the noise group did report significantly poorer mood throughout the task. Conclusions The results of the present study suggest that the acoustic qualities of MRI enhance frustration effects on an affective attentional task and that scanner noise may influence mood during similar fMRI tasks. PMID:26059389

  5. Oral impacts affecting daily performance in a low dental disease Thai population.

    PubMed

    Adulyanon, S; Vourapukjaru, J; Sheiham, A

    1996-12-01

    The aim of the study was to measure incidence of oral impacts on daily performances and their related features in a low dental disease population. 501 people aged 35-44 years in 16 rural villages in Ban Phang district, Khon Kaen, Thailand, were interviewed about oral impacts on nine physical, psychological and social aspects of performance during the past 6 months, and then had an oral examination. The clinical and behavioural data showed that the sample had low caries (DMFT = 2.7) and a low utilization of dental services. 73.6% of all subjects had at least one daily performance affected by an oral impact. The highest incidence of performances affected were Eating (49.7%), Emotional stability (46.5%) and Smiling (26.1%). Eating, Emotional stability and Cleaning teeth performances had a high frequency or long duration of impacts, but a low severity. The low frequency performances; Physical activities, Major role activity and Sleeping were rated as high severity. Pain and discomfort were mainly perceived as the causes of impacts (40.1%) for almost every performance except Smiling. Toothache was the major causal oral condition (32.7%) of almost all aspects of performance. It was concluded that this low caries people have as high an incidence of oral impacts as industrialized, high dental disease populations. Frequency and severity presented the paradoxical effect on different performances and should both be taken into account for overall estimation of impacts. PMID:9007354

  6. Alpha suppression following performance errors is correlated with depression, affect, and coping behaviors.

    PubMed

    Compton, Rebecca J; Hofheimer, Julia; Kazinka, Rebecca; Levinson, Amanda; Zheutlin, Amanda

    2013-10-01

    This study tested the hypothesis that enhanced neural arousal in response to performance errors would predict poor affect and coping behaviors in everyday life. Participants were preselected as either low-depressed (LD) or high-depressed (HD) based on a screening questionnaire, and they then completed a laboratory Stroop task while EEG was recorded, followed by a 2-week period of daily reports of affect and coping behaviors. The EEG measure of arousal response to errors was the degree of error-related alpha suppression (ERAS) in the intertrial interval, that is the reduction in alpha power following errors compared with correct responses. ERAS was relatively heightened at frontal sites for the HD versus the LD group, and frontal ERAS predicted lower positive affect, higher negative affect, and less adaptive coping behaviors in the daily reports. Together, the results imply that heightened arousal following mistakes is associated with suboptimal emotion and coping with stressors. PMID:23731439

  7. ULTRAFINE CARBON PARTICLE (UFCP) INHALATION AFFECTS CARDIOVASCULAR PERFORMANCE IN HYPERTENSIVE RATS (SHR)

    EPA Science Inventory

    Inhaled UfCP affect cardiovascular performance in healthy rats (Harder et al. Inhal Toxicol 2005; 17:29-42) without apparent pulmonary damage. To assess whether geriatric cardiovascular compromised rats are more susceptible to UfCP effects, male adult (6months) and geriatric (13m...

  8. Internal Challenges Affecting Academic Performance of Student-Athletes in Ghanaian Public Universities

    ERIC Educational Resources Information Center

    Apaak, Daniel; Sarpong, Emmanuel Osei

    2015-01-01

    This paper examined internal challenges affecting academic performance of student-athletes in Ghanaian public universities, using a descriptive survey research design. Proportionate random sampling technique was employed to select Three Hundred and Thirty-Two (332) respondents for the study. The instrument used in gathering data for the study was…

  9. Factors Affecting Business Students' Performance: The Case of Students in United Arab Emirates

    ERIC Educational Resources Information Center

    Harb, Nasri; El-Shaarawi, Ahmed

    2007-01-01

    In this study, the authors found that the most important factor that affected student performance was their competence in speaking English. The sample was a group of 864 business and economics students in United Arab Emirates. The authors used regression analysis for the study. The results of the study showed that students who participated in…

  10. Students Perceptions on Factors That Affect Their Academic Performance: The Case of Great Zimbabwe University (GZU)

    ERIC Educational Resources Information Center

    Mapuranga, Barbra; Musingafi, Maxwell C. C.; Zebron, Shupikai

    2015-01-01

    Some educators argue that entry standards are the most important determinants of successful completion of a university programme; others maintain that non-academic factors must also be considered. In this study we sought to investigate open and distance learning students' perceptions of the factors affecting academic performance and successful…

  11. Study of Core Competency Elements and Factors Affecting Performance Efficiency of Government Teachers in Northeastern Thailand

    ERIC Educational Resources Information Center

    Chansirisira, Pacharawit

    2012-01-01

    The research aimed to investigate the core competency elements and the factors affecting the performance efficiency of the civil service teachers in the northeastern region, Thailand. The research procedure consisted of two steps. In the first step, the data were collected using a questionnaire with the reliability (Cronbach's Alpha) of 0.90. The…

  12. Factors Affecting University Entrants' Performance in High-Stakes Tests: A Multiple Regression Analysis

    ERIC Educational Resources Information Center

    Uy, Chin; Manalo, Ronaldo A.; Cabauatan, Ronaldo R.

    2015-01-01

    In the Philippines, students seeking admission to a university are usually required to meet certain entrance requirements, including passing the entrance examinations with questions on IQ and English, mathematics, and science. This paper aims to determine the factors that affect the performance of entrants into business programmes in high-stakes…

  13. Antecedent Factors Affecting Academic Performance of Graduate Students at the Nairobi Evangelical Graduate School of Theology

    ERIC Educational Resources Information Center

    Mbogo, Rosemary Wahu

    2016-01-01

    This paper reports the findings of a Master's level thesis work that was done in 1997 to assess the antecedent factors affecting the academic performance of graduate students at the Nairobi Evangelical School of Theology (N.E.G.S.T.), which is currently Africa International University (AIU). The paper reviews the effect of lack of finance on…

  14. Investigating Effects of Task Structure on EFL Learner's Oral Performance

    ERIC Educational Resources Information Center

    Rahimpour, Massoud; Mehrang, Faezeh

    2010-01-01

    It is argued that tasks with different structures yield different performances in terms of accuracy, fluency and complexity. The present study is thus an attempt to investigate the impact of task structure on second language task performance. Thirty two upper-intermediate Iranian learners of English performed two narrative tasks (Structured vs.…

  15. Mathematics performance and the role played by affective and background factors peter grootenboer and brian hemmings

    NASA Astrophysics Data System (ADS)

    Grootenboer, Peter; Hemmings, Brian

    2007-12-01

    In this article, we report on a study examining those factors which contribute to the mathematics performance of a sample of children aged between 8 and 13 years. The study was designed specifically to consider the potency of a number of mathematical affective factors, as well as background characteristics (viz., gender, ethnicity, and socioeconomic status), on children's mathematics performance. Data were collected by surveying the children and drawing on performance ratings from their teachers. A correlation analysis revealed that the relationships between the respective dispositional and background variables with mathematics performance were significant and in the direction as predicted. Moreover, the findings from a logistic regression showed that a combination of these variables was able to appropriately classify students who either were below-average or above-average mathematics performers. We pay particular attention to the influence of certain dispositions with respect to mathematics performance and conclude by detailing the implications of the study for teachers and researchers.

  16. Universal and culture-specific factors in the recognition and performance of musical affect expressions.

    PubMed

    Laukka, Petri; Eerola, Tuomas; Thingujam, Nutankumar S; Yamasaki, Teruo; Beller, Grégory

    2013-06-01

    We present a cross-cultural study on the performance and perception of affective expression in music. Professional bowed-string musicians from different musical traditions (Swedish folk music, Hindustani classical music, Japanese traditional music, and Western classical music) were instructed to perform short pieces of music to convey 11 emotions and related states to listeners. All musical stimuli were judged by Swedish, Indian, and Japanese participants in a balanced design, and a variety of acoustic and musical cues were extracted. Results first showed that the musicians' expressive intentions could be recognized with accuracy above chance both within and across musical cultures, but communication was, in general, more accurate for culturally familiar versus unfamiliar music, and for basic emotions versus nonbasic affective states. We further used a lens-model approach to describe the relations between the strategies that musicians use to convey various expressions and listeners' perceptions of the affective content of the music. Many acoustic and musical cues were similarly correlated with both the musicians' expressive intentions and the listeners' affective judgments across musical cultures, but the match between musicians' and listeners' uses of cues was better in within-cultural versus cross-cultural conditions. We conclude that affective expression in music may depend on a combination of universal and culture-specific factors. PMID:23398579

  17. Neuropsychological performance and affective temperaments in Euthymic patients with bipolar disorder type II.

    PubMed

    Romero, Ester; Holtzman, Jessica N; Tannenhaus, Lucila; Monchablon, Romina; Rago, Carlo Mario; Lolich, Maria; Vázquez, Gustavo H

    2016-04-30

    Affective temperament has been suggested as a potential mediator of the effect between genetic predisposition and neurocognitive functioning. As such, this report seeks to assess the extent of the correlation between affective temperament and cognitive function in a group of bipolar II subjects. 46 bipolar II outpatients [mean age 41.4 years (SD 18.2); female 58.9%] and 46 healthy controls [mean age 35.1 years (SD 18); female 56.5%] were evaluated with regard to their demographic and clinical characteristics, affective temperament, and neurocognitive performance. Crude bivariate correlation analyses and multiple linear regression models were constructed between five affective temperament subscales and eight neurocognitive domains. Significant correlations were identified in bipolar patients between hyperthymic temperament and verbal memory and premorbid IQ; cyclothymic temperament and attention; and irritable temperament, attention, and verbal fluency. In adjusting for potential confounders of the relationship between temperament and cognitive function, the strongest mediating factors among the euthymic bipolar patients were found to be residual manic and depressive symptoms. It is therefore concluded that affective temperaments may partially influence the neurocognitive performance of both healthy controls and euthymic patients with bipolar disorder type II in several specific domains. PMID:27086230

  18. 28 CFR 0.191 - Changes which affect the overall structure of the Department.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Changes which affect the overall structure of the Department. 0.191 Section 0.191 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Sections and Subunits § 0.191 Changes which affect the overall...

  19. The Internal Structure of Positive and Negative Affect: A Confirmatory Factor Analysis of the PANAS

    ERIC Educational Resources Information Center

    Tuccitto, Daniel E.; Giacobbi, Peter R., Jr.; Leite, Walter L.

    2010-01-01

    This study tested five confirmatory factor analytic (CFA) models of the Positive Affect Negative Affect Schedule (PANAS) to provide validity evidence based on its internal structure. A sample of 223 club sport athletes indicated their emotions during the past week. Results revealed that an orthogonal two-factor CFA model, specifying error…

  20. A Quality Improvement Study on Avoidable Stressors and Countermeasures Affecting Surgical Motor Performance and Learning

    PubMed Central

    Conrad, Claudius; Konuk, Yusuf; Werner, Paul D.; Cao, Caroline G.; Warshaw, Andrew L.; Rattner, David W.; Stangenberg, Lars; Ott, Harald C.; Jones, Daniel B.; Miller, Diane L; Gee, Denise W.

    2012-01-01

    OBJECTIVE To explore how the two most important components of surgical performance - speed and accuracy - are influenced by different forms of stress and what the impact of music on these factors is. SUMMARY BACKGROUND DATA Based on a recently published pilot study on surgical experts, we designed an experiment examining the effects of auditory stress, mental stress, and music on surgical performance and learning, and then correlated the data psychometric measures to the role of music in a novice surgeon’s life. METHODS 31 surgeons were recruited for a crossover study. Surgeons were randomized to four simple standardized tasks to be performed on the Surgical SIM VR laparoscopic simulator, allowing exact tracking of speed and accuracy. Tasks were performed under a variety of conditions, including silence, dichotic music (auditory stress), defined classical music (auditory relaxation), and mental loading (mental arithmetic tasks). Tasks were performed twice to test for memory consolidation and to accommodate for baseline variability. Performance was correlated to the Brief Musical Experience Questionnaire (MEQ). RESULTS Mental loading influences performance with respect to accuracy, speed, and recall more negatively than does auditory stress. Defined classical music might lead to minimally worse performance initially, but leads to significantly improved memory consolidation. Furthermore, psychologic testing of the volunteers suggests that surgeons with greater musical commitment, measured by the MEQ, perform worse under the mental loading condition. CONCLUSION Mental distraction and auditory stress negatively affect specific components of surgical learning and performance. If used appropriately, classical music may positively affect surgical memory consolidation. It also may be possible to predict surgeons’ performance and learning under stress through psychological tests on the role of music in a surgeon’s life. Further investigation is necessary to determine

  1. How sleep deprivation affects psychological variables related to college students' cognitive performance.

    PubMed

    Pilcher, J J; Walters, A S

    1997-11-01

    The effects of sleep deprivation on cognitive performance psychological variables related to cognitive performance were studied in 44 college students. Participants completed the Watson-Glaser Critical Thinking Appraisal after either 24 hours of sleep deprivation or approximately 8 hours of sleep. After completing the cognitive task, the participants completed 2 questionnaires, one assessing self-reported effort, concentration, and estimated performance, the other assessing off-task cognitions. As expected, sleep-deprived participants performed significantly worse than the nondeprived participants on the cognitive task. However, the sleep-deprived participants rated their concentration and effort higher than the nondeprived participants did. In addition, the sleep-deprived participants rated their estimated performance significantly higher than the nondeprived participants did. The findings indicate that college students are not aware of the extent to which sleep deprivation negatively affects their ability to complete cognitive tasks. PMID:9394089

  2. Gender Differences in Introductory University Physics Performance: The Influence of High School Physics Preparation and Affect

    NASA Astrophysics Data System (ADS)

    Hazari, Zahra

    2006-12-01

    The attrition of females studying physics after high school has been a continuing concern for the physics education community. If females are well prepared, feel confident, and do well in introductory college physics, they may be inclined to study physics further. This quantitative study uses HLM to identify factors from high school physics preparation (content, pedagogy, and assessment) and the affective domain that predict female and male performance in introductory college physics. The study includes controls for student demographic and academic background characteristics, and the final dataset consists of 1973 surveys from 54 introductory college physics classes. The results highlight high school physics and affective experiences that differentially predict female and male performance. These experiences include: learning requirements, computer graphing/analysis, long written problems, everyday world examples, community projects cumulative tests/quizzes, father's encouragement, family's belief that science leads to a better career, and the length of time students believe that high school physics would help in university physics. There were also experiences that similarly predict female and male performance. The results paint a dynamic picture of the factors from high school physics and the affective domain that influence the future physics performance of females and males. The implication is that there are many aspects to the teaching of physics in high school that, although widely used and thought to be effective, need reform in their implementation in order to be fully beneficial to females and/or males in college.

  3. Structures performance, benefit, cost-study

    NASA Technical Reports Server (NTRS)

    Woike, O. G.; Salemme, C.; Stearns, E.; Oritz, P.; Roberts, M. L.; Baughman, J. L.; Johnston, R. P.; Demel, H. F.; Stabrylla, R. G.; Coffinberry, G. A.

    1981-01-01

    New technology concepts and structural analysis development needs which could lead to improved life cycle cost for future high-bypass turbofans were studied. The NASA-GE energy efficient engine technology is used as a base to assess the concept benefits. Recommended programs are identified for attaining these generic structural and other beneficial technologies.

  4. Human resources management and firm performance: The differential role of managerial affective and continuance commitment.

    PubMed

    Gong, Yaping; Law, Kenneth S; Chang, Song; Xin, Katherine R

    2009-01-01

    In this study, the authors developed a dual-concern (i.e., maintenance and performance) model of human resources (HR) management. The authors identified commonly examined HR practices that apply to the middle manager level and classified them into the maintenance- and performance-oriented HR subsystems. The authors found support for the 2-factor model on the basis of responses from 2,148 managers from 463 firms operating in China. Regression results indicate that the performance-oriented HR subsystems had a positive relationship with firm performance and that the relationship was mediated by middle managers' affective commitment to the firm. The maintenance-oriented HR subsystems had a positive relationship with middle managers' continuance commitment but not with their affective commitment and firm performance. This study contributes to the understanding of how HR practices relate to firm performance and offers an improved test of the argument that valuable and firm-specific HR provide a source of competitive advantage. (PsycINFO Database Record (c) 2009 APA, all rights reserved). PMID:19186911

  5. Centrality and charisma: comparing how leader networks and attributions affect team performance.

    PubMed

    Balkundi, Prasad; Kilduff, Martin; Harrison, David A

    2011-11-01

    When leaders interact in teams with their subordinates, they build social capital that can have positive effects on team performance. Does this social capital affect team performance because subordinates come to see the leader as charismatic? We answered this question by examining 2 models. First, we tested the charisma-to-centrality model according to which the leader's charisma facilitates the occupation of a central position in the informal advice network. From this central position, the leader positively influences team performance. Second, we examined the centrality-to-charisma model according to which charisma is attributed to those leaders who are socially active in terms of giving and receiving advice. Attributed charisma facilitates increased team performance. We tested these 2 models in 2 different studies. In the first study, based on time-separated, multisource data emanating from members of 56 work teams, we found support for the centrality-to-charisma model. Formal leaders who were central within team advice networks were seen as charismatic by subordinates, and this charisma was associated with high team performance. To clarify how leader network centrality affected the emergence of charismatic leadership, we designed Study 2 in which, for 79 student teams, we measured leader networking activity and leader charisma at 2 different points in time and related these variables to team performance measured at a third point in time. On the basis of this temporally separated data set, we again found support for the centrality-to-charisma model. PMID:21895351

  6. Does the inclusion of protease inhibitors in the insemination extender affect rabbit reproductive performance?

    PubMed

    Casares-Crespo, L; Vicente, J S; Talaván, A M; Viudes-de-Castro, M P

    2016-03-15

    The bioavailability of buserelin acetate when added to the seminal dose appears to be determined by the activity of the existing aminopeptidases. Thus, the addition of aminopeptidase inhibitors to rabbit semen extenders could be a solution to decrease the hormone degradation. This study was conducted to evaluate the effect of the protease activity inhibition on rabbit semen quality parameters and reproductive performance after artificial insemination. Seminal quality was not affected by the incubation with protease inhibitors, being the values of motility, viability, and acrosome integrity not significantly different between the protease inhibitors and the control group. In addition, seminal plasma aminopeptidase activity was inhibited in a 55.1% by the protease inhibitors. On the other hand, regarding the effect of protease inhibitors on reproductive performance, our results showed that the presence of protease inhibitors affected the prolificacy rate (9.2 ± 0.26 and 9.3 ± 0.23 vs. 8.2 ± 0.22 total born per litter for negative control, positive control, and aminopeptidase inhibitors group, respectively; P < 0.05), having this group one kit less per delivery. We conclude that the addition of a wide variety of protease inhibitors in the rabbit semen extender negatively affects prolificacy rate. Therefore, the development of new extenders with specific aminopeptidase inhibitors would be one of the strategies to increase the bioavailability of GnRH analogues without affecting the litter size. PMID:26639641

  7. Using representations in geometry: a model of students' cognitive and affective performance

    NASA Astrophysics Data System (ADS)

    Panaoura, Areti

    2014-05-01

    Self-efficacy beliefs in mathematics, as a dimension of the affective domain, are related with students' performance on solving tasks and mainly on overcoming cognitive obstacles. The present study investigated the interrelations of cognitive performance on geometry and young students' self-efficacy beliefs about using representations for solving geometrical tasks. The emphasis was on confirming a theoretical model for the primary-school and secondary-school students and identifying the differences and similarities for the two ages. A quantitative study was developed and data were collected from 1086 students in Grades 5-8. Confirmatory factor analysis affirmed the existence of a coherent model of affective dimensions about the use of representations for understanding the geometrical concepts, which becomes more stable across the educational levels.

  8. Does mechanical disturbance affect the performance and species composition of submerged macrophyte communities?

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Xu, Ying-Shou; Huang, Lin; Xue, Wei; Sun, Gong-Qi; Zhang, Ming-Xiang; Yu, Fei-Hai

    2014-05-01

    Submerged macrophyte communities are frequently subjected to disturbance of various frequency and strength. However, there is still little experimental evidence on how mechanical disturbance affects the performance and species composition of such plant communities. In a greenhouse experiment, we constructed wetland communities consisting of five co-occurring clonal submerged macrophyte species (Hydrilla verticillata, Elodea canadensis, Ceratophyllum demersum, Chara fragilis, and Myriophyllum spicatum) and subjected these communities to three mechanical disturbance regimes (no, moderate and strong disturbance). Strong mechanical disturbance greatly decreased overall biomass, number of shoot nodes and total shoot length, and increased species diversity (evenness) of the total community. It also substantially decreased the growth of the most abundant species (H. verticillata), but did not affect growth of the other four species. Our data reveal that strong disturbance can have different effects on different submerged macrophyte species and thus alters the performance and species composition of submerged macrophyte communities.

  9. Does mechanical disturbance affect the performance and species composition of submerged macrophyte communities?

    PubMed

    Zhang, Qian; Xu, Ying-Shou; Huang, Lin; Xue, Wei; Sun, Gong-Qi; Zhang, Ming-Xiang; Yu, Fei-Hai

    2014-01-01

    Submerged macrophyte communities are frequently subjected to disturbance of various frequency and strength. However, there is still little experimental evidence on how mechanical disturbance affects the performance and species composition of such plant communities. In a greenhouse experiment, we constructed wetland communities consisting of five co-occurring clonal submerged macrophyte species (Hydrilla verticillata, Elodea canadensis, Ceratophyllum demersum, Chara fragilis, and Myriophyllum spicatum) and subjected these communities to three mechanical disturbance regimes (no, moderate and strong disturbance). Strong mechanical disturbance greatly decreased overall biomass, number of shoot nodes and total shoot length, and increased species diversity (evenness) of the total community. It also substantially decreased the growth of the most abundant species (H. verticillata), but did not affect growth of the other four species. Our data reveal that strong disturbance can have different effects on different submerged macrophyte species and thus alters the performance and species composition of submerged macrophyte communities. PMID:24811826

  10. School and Classroom Goal Structures: Effects on Affective Responses in Physical Education

    ERIC Educational Resources Information Center

    Barkoukis, Vassilis; Koidou, Eirini; Tsorbatzoudis, Haralambos; Grouios, George

    2012-01-01

    The current study examined the relative impact of school and classroom goal structures on students' affective responses and the mediating role of motivation. The sample of the study consisted of 368 high school students, who completed measures of school and classroom goal structures, motivational regulations in physical education, boredom, and…

  11. Factors Affecting the Battery Performance of Anthraquinone-based Organic Cathode Materials

    SciTech Connect

    Xu, Wu; Read, Adam L.; Koech, Phillip K.; Hu, Dehong; Wang, Chong M.; Xiao, Jie; Padmaperuma, Asanga B.; Graff, Gordon L.; Liu, Jun; Zhang, Jiguang

    2012-02-01

    Two organic cathode materials based on poly(anthraquinonyl sulfide) structure with different substitution positions were synthesized and their electrochemical behavior and battery performances were investigated. The substitution positions on the anthraquinone structure, binders for electrode preparation and electrolyte formulations have been found to have significant effects on the battery performances of such organic cathode materials. The substitution position with less steric stress has higher capacity, longer cycle life and better high-rate capability. Polyvinylidene fluoride binder and ether-based electrolytes are favorable for the high capacity and long cycle life of the quinonyl organic cathodes.

  12. Bisphenol A does not affect memory performance in adult male rats.

    PubMed

    Kuwahara, Rika; Kawaguchi, Shinichiro; Kohara, Yumi; Jojima, Takeshi; Yamashita, Kimihiro

    2014-04-01

    Bisphenol A (BPA) is an estrogenic endocrine disruptor used for producing polycarbonate plastics and epoxy resins. This study investigated the effects of oral BPA administration on memory performance, general activity, and emotionality in adult male Sprague Dawley rats using a battery of behavioral tests, including an appetite-motivated maze test (MAZE test) used to assess spatial memory performance. In addition, in order to confirm the effects of BPA on spatial memory performance, we examined whether intrahippocampal injection of BPA affects spatial memory consolidation. In the MAZE test, although oral BPA administration at 10 mg/kg significantly altered the number of entries into the incorrect area compared to those of vehicle-treated rats, male rats given BPA through either oral administration or intrahippocampal injection failed to show significant differences in latencies to reach the reward. Also, oral BPA administration did not affect fear-motivated memory performance in the step-through passive avoidance test. Oral BPA administration at 0.05 mg/kg, the lowest dose used in this study, was correlated with a decrease in locomotor activity in the open-field test, whereas oral administration at 10 mg/kg, the highest dose used in this study, was correlated with a light anxiolytic effect in the elevated plus-maze test. The present study suggests that BPA in adulthood has little effect on spatial memory performance in male rats. PMID:24326521

  13. Tadpole swimming performance and activity affected by acute exposure to sublethal levels of carbaryl

    USGS Publications Warehouse

    Bridges, C.M.

    1997-01-01

    General activity and swimming performance (i.e., sprint speed and distance) of plains leopard frog tadpoles (Rana blairi) were examined after acute exposure to three sublethal concentrations of carbaryl (3.5, 5.0, and 7.2 mg/L). Both swimming performance and spontaneous swimming activity are important for carrying out life history functions (e.g., growth and development) and for escaping from predators. Measured tadpole activity diminished by nearly 90% at 3.5 mg/L carbaryl and completely ceased at 7.2 mg/L. Sprint speed and sprint distance also decreased significantly following exposure. Carbaryl affected both swimming performance and activity after just 24 h, suggesting that 24 h may be an adequate length of exposure to determine behavioral effects on tadpoles. Slight recovery of activity levels was noted at 24 and 48 h post-exposure; no recovery of swimming performance was observed. Reduction in activity and swimming performance may result in increased predation rates and, because activity is closely associated with feeding, may result in slowed growth leading to a failure to emerge before pond drying or an indirect reduction in adult fitness. Acute exposure to sublethal toxicants such as carbaryl may not only affect immediate survival of tadpoles but also impact critical life history functions and generate changes at the local population level.

  14. Individual differences in cognition, affect, and performance: Behavioral, neuroimaging, and molecular genetic approaches

    PubMed Central

    Parasuraman, Raja; Jiang, Yang

    2012-01-01

    We describe the use of behavioral, neuroimaging, and genetic methods to examine individual differences in cognition and affect, guided by three criteria: (1) relevance to human performance in work and everyday settings; (2) interactions between working memory, decision-making, and affective processing; and (3) examination of individual differences. The results of behavioral, functional MRI (fMRI), event-related potential (ERP), and molecular genetic studies show that analyses at the group level often mask important findings associated with sub-groups of individuals. Dopaminergic/noradrenergic genes influencing prefrontal cortex activity contribute to inter-individual variation in working memory and decision behavior, including performance in complex simulations of military decision-making. The interactive influences of individual differences in anxiety, sensation seeking, and boredom susceptibility on evaluative decision-making can be systematically described using ERP and fMRI methods. We conclude that a multi-modal neuroergonomic approach to examining brain function (using both neuroimaging and molecular genetics) can be usefully applied to understanding individual differences in cognition and affect and has implications for human performance at work. PMID:21569853

  15. Gradient Index Microlens Implanted in Prefrontal Cortex of Mouse Does Not Affect Behavioral Test Performance over Time

    PubMed Central

    Lee, Seon A.; Holly, Kevin S.; Voziyanov, Vladislav; Villalba, Stephanie L.; Tong, Rudi; Grigsby, Holly E.; Glasscock, Edward; Szele, Francis G.; Vlachos, Ioannis; Murray, Teresa A.

    2016-01-01

    Implanted gradient index lenses have extended the reach of standard multiphoton microscopy from the upper layers of the mouse cortex to the lower cortical layers and even subcortical regions. These lenses have the clarity to visualize dynamic activities, such as calcium transients, with subcellular and millisecond resolution and the stability to facilitate repeated imaging over weeks and months. In addition, behavioral tests can be used to correlate performance with observed changes in network function and structure that occur over time. Yet, this raises the questions, does an implanted microlens have an effect on behavioral tests, and if so, what is the extent of the effect? To answer these questions, we compared the performance of three groups of mice in three common behavioral tests. A gradient index lens was implanted in the prefrontal cortex of experimental mice. We compared their performance with mice that had either a cranial window or a sham surgery. Three presurgical and five postsurgical sets of behavioral tests were performed over seven weeks. Behavioral tests included rotarod, foot fault, and Morris water maze. No significant differences were found between the three groups, suggesting that microlens implantation did not affect performance. The results for the current study clear the way for combining behavioral studies with gradient index lens imaging in the prefrontal cortex, and potentially other regions of the mouse brain, to study structural, functional, and behavioral relationships in the brain. PMID:26799938

  16. The Histamine N-Methyltransferase T105I Polymorphism Affects Active Site Structure and Dynamics†

    PubMed Central

    Rutherford, Karen; Parson, William W.; Daggett, Valerie

    2010-01-01

    Histamine N-methyltransferase (HNMT) is the sole enzyme responsible for inactivating histamine in the mammalian brain. The human HNMT gene contains a common threonine-isoleucine polymorphism at residue 105, distal from the active site. The 105I variant has decreased activity and lower protein levels relative to the 105T protein. Crystal structures of both variants have been solved, but reveal little regarding how the T105I polymorphism affects activity. We performed molecular dynamics simulations of both 105T and 105I at 37°C to explore the structural and dynamic consequences of the polymorphism. The simulations indicate that replacing Thr with the larger Ile residue leads to greater burial of residue 105 and heightened packing interactions between residue105 and residues within helix α3 and strand β3. This altered packing is directly translated to the active site resulting in the reorientation of several co-substrate-binding residues. The simulations also show that the hydrophobic histamine-binding domain in both proteins undergoes a large-scale breathing motion that exposes key catalytic residues and lessens the hydrophobicity of the substrate-binding site. PMID:18154359

  17. Nanopillar array structures for enhancing biosensing performance

    PubMed Central

    Anandan, Venkataramani; Rao, Yeswanth L; Zhang, Guigen

    2006-01-01

    Fabrication of metallic nanopillar array structures and their application as electrodes in electrochemical-based biosensors are discussed in this report. Vertically standing nanopillar array structures were fabricated using an electrodeposition technique and their electrochemical characteristics were evaluated. For possible use in biosensing applications, these standing nanopillars should have sufficient mechanical stability to sustain the capillary forces caused by the nanopillar – liquid interactions in aqueous environment and should provide increased signal response in an electrochemical process. Our results showed that the developed nanopillar arrays were mechanically stable in aqueous environments and the nanostructured electrodes exhibited increased electrochemical response compared with flat electrodes. PMID:17722264

  18. Improved Dynamic Modeling of the Cascade Distillation Subsystem and Analysis of Factors Affecting Its Performance

    NASA Technical Reports Server (NTRS)

    Perry, Bruce A.; Anderson, Molly S.

    2015-01-01

    The Cascade Distillation Subsystem (CDS) is a rotary multistage distiller being developed to serve as the primary processor for wastewater recovery during long-duration space missions. The CDS could be integrated with a system similar to the International Space Station Water Processor Assembly to form a complete water recovery system for future missions. A preliminary chemical process simulation was previously developed using Aspen Custom Modeler® (ACM), but it could not simulate thermal startup and lacked detailed analysis of several key internal processes, including heat transfer between stages. This paper describes modifications to the ACM simulation of the CDS that improve its capabilities and the accuracy of its predictions. Notably, the modified version can be used to model thermal startup and predicts the total energy consumption of the CDS. The simulation has been validated for both NaC1 solution and pretreated urine feeds and no longer requires retuning when operating parameters change. The simulation was also used to predict how internal processes and operating conditions of the CDS affect its performance. In particular, it is shown that the coefficient of performance of the thermoelectric heat pump used to provide heating and cooling for the CDS is the largest factor in determining CDS efficiency. Intrastage heat transfer affects CDS performance indirectly through effects on the coefficient of performance.

  19. Integrating affective and cognitive correlates of heart rate variability: A structural equation modeling approach.

    PubMed

    Mann, Sarah L; Selby, Edward A; Bates, Marsha E; Contrada, Richard J

    2015-10-01

    High frequency heart rate variability (HRV) is a measure of neurocardiac communication thought to reflect predominantly parasympathetic cardiac regulation. Low HRV has been associated empirically with clinical and subclinical levels of anxiety and depression and, more recently, high levels of HRV have been associated with better performance on some measures of executive functioning (EF). These findings have offered support for theories proposing HRV as an index measure of a broad, self-regulatory capacity underlying aspects of emotion regulation and executive control. This study sought to test that proposition by using a structural equation modeling approach to examine the relationships of HRV to negative affect (NA) and EF in a large sample of U.S. adults ages 30s-80s. HRV was modeled as a predictor of an NA factor (self-reported trait anxiety and depression symptoms) and an EF factor (performance on three neuropsychological tests tapping facets of executive abilities). Alternative models also were tested to determine the utility of HRV for predicting NA and EF, with and without statistical control of demographic and health-related covariates. In the initial structural model, HRV showed a significant positive relationship to EF and a nonsignificant relationship to NA. In a covariate-adjusted model, HRV's associations with both constructs were nonsignificant. Age emerged as the only significant predictor of NA and EF in the final model, showing inverse relationships to both. Findings may reflect population and methodological differences from prior research; they also suggest refinements to the interpretations of earlier findings and theoretical claims regarding HRV. PMID:26168884

  20. Light conditions affect sexual performance in a lekking tephritid fruit fly.

    PubMed

    Díaz-Fleischer, Francisco; Arredondo, José

    2011-08-01

    Sensory systems are very susceptible to early environment experience. Mating success depends on the transmission of information from the signaller to the receiver, which means that sensory biases caused by developmental environment are likely to affect sexual selection. We investigated the impact of the developmental visual environment (light spectrum) on male copulation behaviour and female preference in the lekking tephritid Anastrepha ludens. We reared flies in four different light spectrum conditions - red light, blue light, shaded light and darkness - during their first 16 days after emerging from pupae. We found that the light environment experienced during early adulthood affected mating frequency and, in some cases, the latency to copulate, but not copulation duration. Males exposed to any of the three light treatments (red, blue or shaded light) were more frequently chosen as mating partners than dark-reared males. Flies reared under dark conditions exhibited the lowest mating performance out of any of the rearing environments. Under field cage conditions, a slight assortative mating between blue- and red-light-reared flies was detected. Additionally, females reared in blue light and darkness mated less compared with females reared in red and shaded light. Our data demonstrate that male mating behaviour is flexible in response to light environment. The findings suggest that light spectrum only weakly affects the direction of sexual selection by female choice; however, dark rearing environments deeply affect mating success. PMID:21753054

  1. How Explicit and Implicit Test Instructions in an Implicit Learning Task Affect Performance

    PubMed Central

    Witt, Arnaud; Puspitawati, Ira; Vinter, Annie

    2013-01-01

    Typically developing children aged 5 to 8 years were exposed to artificial grammar learning. Following an implicit exposure phase, half of the participants received neutral instructions at test while the other half received instructions making a direct, explicit reference to the training phase. We first aimed to assess whether implicit learning operated in the two test conditions. We then evaluated the differential impact of age on learning performances as a function of test instructions. The results showed that performance did not vary as a function of age in the implicit instructions condition, while age effects emerged when explicit instructions were employed at test. However, performance was affected differently by age and the instructions given at test, depending on whether the implicit learning of short or long units was assessed. These results suggest that the claim that the implicit learning process is independent of age needs to be revised. PMID:23326409

  2. Distractions, distractions: does instant messaging affect college students' performance on a concurrent reading comprehension task?

    PubMed

    Fox, Annie Beth; Rosen, Jonathan; Crawford, Mary

    2009-02-01

    Instant messaging (IM) has become one of the most popular forms of computer-mediated communication (CMC) and is especially prevalent on college campuses. Previous research suggests that IM users often multitask while conversing online. To date, no one has yet examined the cognitive effect of concurrent IM use. Participants in the present study (N = 69) completed a reading comprehension task uninterrupted or while concurrently holding an IM conversation. Participants who IMed while performing the reading task took significantly longer to complete the task, indicating that concurrent IM use negatively affects efficiency. Concurrent IM use did not affect reading comprehension scores. Additional analyses revealed that the more time participants reported spending on IM, the lower their reading comprehension scores. Finally, we found that the more time participants reported spending on IM, the lower their self-reported GPA. Implications and future directions are discussed. PMID:19006461

  3. Category fluency performance in patients with schizophrenia and bipolar disorder: The influence of affective categories.

    PubMed

    Rossell, Susan L

    2006-02-28

    Semantic fluency (SF) and phonological fluency (PF) were examined in large groups of schizophrenia patients, bipolar patients and controls. As well as standard SF categories (animals and food), fluency to two affective categories, happy and fear was measured, i.e. participants were asked to produce as many words as they could that resulted in or are associated with fear or happiness. Schizophrenia patients showed SF and PF deficits. Bipolar patients showed PF deficits. Thus, PF is argued to be a good cognitive marker in both disorders. Severity of delusions was related to SF performance in all patients. The patient groups showed different patterns on the affective categories compared to controls: the bipolar patients were better and produced more words, especially to the happiness category, and the schizophrenia patients were impaired and produced less words. The results suggest an interesting interaction between psychotic illnesses, fluency and emotion. PMID:16376054

  4. Gender differences in introductory university physics performance: The influence of high school physics preparation and affect

    NASA Astrophysics Data System (ADS)

    Hazari, Zahra Sana

    The attrition of females studying physics after high school is a concern to the science education community. Most undergraduate science programs require introductory physics coursework. Thus, success in introductory physics is necessary for students to progress to higher levels of science study. Success also influences attitudes; if females are well-prepared, feel confident, and do well in introductory physics, they may be inclined to study physics further. This quantitative study using multilevel modeling focused on determining factors from high school physics preparation (content, pedagogy, and assessment) and the affective domain that influenced female and male performance in introductory university physics. The study controlled for some university/course level characteristics as well as student demographic and academic background characteristics. The data consisted of 1973 surveys from 54 introductory physics courses within 35 universities across the US. The results highlight high school physics and affective experiences that differentially influenced female and male performance. These experiences include: learning requirements, computer graphing/analysis, long written problems, everyday world examples, community projects, cumulative tests/quizzes, father's encouragement, family's belief that science leads to a better career, and the length of time students believed that high school physics would help in university physics. There were also experiences that had a similar influence on female and male performance. Positively related to performance were: covering fewer topics for longer periods of time, the history of physics as a recurring topic, physics-related videos, and test/quiz questions that involved calculations and/or were drawn from standardized tests. Negatively related to performance were: student-designed projects, reading/discussing labs the day before performing them, microcomputer based laboratories, discussion after demonstrations, and family

  5. Study of parameters affecting the performance of solar desiccant cooling systems

    NASA Astrophysics Data System (ADS)

    Pesaran, A. A.; Hoo, E. A.

    1993-01-01

    The performance of a solar desiccant cooling system depends on the performance of its components, particularly the desiccant dehumidifier and solar collectors. The desiccant dehumidifier performance is affected by the properties of the desiccant, particularly the shape of the isotherm and the regeneration temperature. The performance of a solar collector, as one would expect, depends on its operating temperature, which is very close to the desiccant regeneration temperature. The purpose of this study was to identify the desiccant isotherm shape (characterized by separation factor) that would result in the optimum performance - based on thermal coefficient of performance and cooling capacity - of a desiccant cooling cycle operating in ventilation mode. Different regeneration temperatures ranging from 65 to 160 C were investigated to identify the corresponding optimum isotherm shape at each. Thermal COP dictates the required area of the solar collectors, and the cooling capacity is an indication of the size and cost of the cooling equipment. Staged and no-staged regeneration methods were studied.

  6. High-performance computing in structural mechanics and engineering

    SciTech Connect

    Adeli, H.; Kamat, M.P.; Kulkarni, G.; Vanluchene, R.D. Georgia Inst. of Technology, Atlanta Montana State Univ., Bozeman )

    1993-07-01

    Recent advances in computer hardware and software have made multiprocessing a viable and attractive technology. This paper reviews high-performance computing methods in structural mechanics and engineering through the use of a new generation of multiprocessor computers. The paper presents an overview of vector pipelining, performance metrics for parallel and vector computers, programming languages, and general programming considerations. Recent developments in the application of concurrent processing techniques to the solution of structural mechanics and engineering problems are reviewed, with special emphasis on linear structural analysis, nonlinear structural analysis, transient structural analysis, dynamics of multibody flexible systems, and structural optimization. 64 refs.

  7. Timing of examinations affects school performance differently in early and late chronotypes.

    PubMed

    van der Vinne, Vincent; Zerbini, Giulia; Siersema, Anne; Pieper, Amy; Merrow, Martha; Hut, Roelof A; Roenneberg, Till; Kantermann, Thomas

    2015-02-01

    Circadian clocks of adolescents typically run late-including sleep times-yet adolescents generally are expected at school early in the morning. Due to this mismatch between internal (circadian) and external (social) times, adolescents suffer from chronic sleep deficiency, which, in turn, affects academic performance negatively. This constellation affects students' future career prospects. Our study correlates chronotype and examination performance. In total, 4734 grades were collected from 741 Dutch high school students (ages 11-18 years) who had completed the Munich ChronoType Questionnaire to estimate their internal time. Overall, the lowest grades were obtained by students who were very late chronotypes (MSFsc > 5.31 h) or slept very short on schooldays (SDw < 7.03 h). The effect of chronotype on examination performance depended on the time of day that examinations were taken. Opposed to late types, early chronotypes obtained significantly higher grades during the early (0815-0945 h) and late (1000-1215 h) morning. This group difference in grades disappeared in the early afternoon (1245-1500 h). Late types also obtained lower grades than early types when tested at the same internal time (hours after MSFsc), which may reflect general attention and learning disadvantages of late chronotypes during the early morning. Our results support delaying high school starting times as well as scheduling examinations in the early afternoon to avoid discrimination of late chronotypes and to give all high school students equal academic opportunities. PMID:25537752

  8. Swimming performance of hatchling green turtles is affected by incubation temperature

    NASA Astrophysics Data System (ADS)

    Burgess, Elizabeth A.; Booth, David T.; Lanyon, Janet M.

    2006-08-01

    In an experiment repeated for two separate years, incubation temperature was found to affect the body size and swimming performance of hatchling green turtles ( Chelonia mydas). In the first year, hatchlings from eggs incubated at 26°C were larger in size than hatchlings from 28 and 30°C, whilst in the second year hatchlings from 25.5°C were similar in size to hatchings from 30°C. Clutch of origin influenced the size of hatchlings at all incubation temperatures even when differences in egg size were taken into account. In laboratory measurements of swimming performance, in seawater at 28°C, hatchlings from eggs incubated at 25.5 and 26°C had a lower stroke rate frequency and lower force output than hatchlings from 28 and 30°C. These differences appeared to be caused by the muscles of hatchlings from cooler temperatures fatiguing at a faster rate. Clutch of origin did not influence swimming performance. This finding that hatchling males incubated at lower temperature had reduced swimming ability may affect their survival whilst running the gauntlet of predators in shallow near-shore waters, prior to reaching the relative safety of the open sea.

  9. Effects of drought-affected corn and nonstarch polysaccharide enzyme inclusion on nursery pig growth performance.

    PubMed

    Jones, C K; Frantz, E L; Bingham, A C; Bergstrom, J R; DeRouchey, J M; Patience, J F

    2015-04-01

    The effectiveness of carbohydrase enzymes has been inconsistent in corn-based swine diets; however, the increased substrate of nonstarch polysaccharides in drought-affected corn may provide an economic model for enzyme inclusion, but this has not been evaluated. A total of 360 barrows (PIC 1050 × 337, initially 5.85 kg BW) were used to determine the effects of drought-affected corn inclusion with or without supplementation of commercial carbohydrases on growth performance and nutrient digestibility of nursery pigs. Initially, 34 corn samples were collected to find representatives of normal and drought-affected corn. The lot selected to represent the normal corn had a test weight of 719.4 kg/m3, 15.0% moisture, and 4.2% xylan. The lot selected to represent drought-affected corn had a test weight of 698.8 kg/m3, 14.3% moisture, and 4.7% xylan. After a 10-d acclimation period postweaning, nursery pigs were randomly allotted to 1 of 8 dietary treatments in a completely randomized design. Treatments were arranged in a 2 × 4 factorial with main effects of corn (normal vs. drought affected) and enzyme inclusion (none vs. 100 mg/kg Enzyme A vs. 250 mg/kg Enzyme B vs. 100 mg/kg Enzyme A + 250 mg/kg Enzyme B). Both enzymes were included blends of β-glucanase, cellulose, and xylanase (Enzyme A) or hemicellulase and pectinases (Enzyme B). Pigs were fed treatment diets from d 10 to 35 postweaning in 2 phases. Feed and fecal samples were collected on d 30 postweaning to determine apparent total tract digestibility of nutrients. The nutrient concentrations of normal and drought-affected corn were similar, which resulted in few treatment or main effects differences of corn type or enzyme inclusion. No interactions were observed (P > 0.10) between corn source and enzyme inclusion. Overall (d 10 to 35), treatments had no effect on ADG or ADFI, but enzyme A inclusion tended to improve (P < 0.10; 0.74 vs. 0.69) G:F, which was primarily driven by the improved feed efficiency (0

  10. Factors that affect reliability of nondestructive detection of flaws in structural ceramics

    NASA Technical Reports Server (NTRS)

    Klima, S. J.; Baaklini, G. Y.; Roth, D. J.

    1986-01-01

    The factors that affect reliability of nondestructive detection of flaws in structural ceramics by microfocus radiography and scanning laser acoustic microscopy (SLAM) were investigated. Reliability of void detection in silicon nitride and silicon carbide by microfocus X-rays was affected by photon energy level, material chemistry in the immediate vicinity of the void, and the presence of loose powder aggregates inside the void cavity. The sensitivity of SLAM to voids was affected by material microstructure, the level of porosity, and the condition of the specimen surfaces. Statistical results are presented in the form of probability of detection as a function of void diameter for green compacts and sintered materials.

  11. Structure and performance of carbon aerogel electrodes

    SciTech Connect

    Pekala, R.W.; Mayer, S.T.; Poco, J.F.; Kaschmitter, J.L.

    1994-03-01

    The chemistry and physics of small clusters of atoms (1--100 nm) has received considerable attention in recent years because these assemblies often have properties between the molecular and bulk solid-state limits. The different properties can be explained in terms of the large fraction of atoms that are at the surface of a cluster as compared to the interior. Although the synthesis and properties of metal and. semiconductor clusters, metallocarbohedrenes, fullerenes, and nanotubes are the subject of extensive investigations, little attention has been paid to cluster-assembled porous materials. This oversight is of particular interest to us since we believe that aerogels are one of the few monolithic materials presently available where the benefits of cluster assembly can be demonstrated. In particular, the unique optical, thermal, acoustic, mechanical, and electrical properties of aerogels are directly related to their nanostructure, which is composed of interconnected particles (3--30 nm) with small interstitial pores (< 50 nm). This structure leads to extremely high surface areas (400--1100 m{sup 2}/g) with a large fraction of the atoms covering the surface of the interconnected particles. As a result of these structural features, carbon aerogels are finding applications as electrodes in supercapacitors with high energy and power densities.

  12. Severe hypoxia affects exercise performance independently of afferent feedback and peripheral fatigue.

    PubMed

    Millet, Guillaume Y; Muthalib, Makii; Jubeau, Marc; Laursen, Paul B; Nosaka, Kazunori

    2012-04-01

    To test the hypothesis that hypoxia centrally affects performance independently of afferent feedback and peripheral fatigue, we conducted two experiments under complete vascular occlusion of the exercising muscle under different systemic O(2) environmental conditions. In experiment 1, 12 subjects performed repeated submaximal isometric contractions of the elbow flexor to exhaustion (RCTE) with inspired O(2) fraction fixed at 9% (severe hypoxia, SevHyp), 14% (moderate hypoxia, ModHyp), 21% (normoxia, Norm), or 30% (hyperoxia, Hyper). The number of contractions (performance), muscle (biceps brachii), and prefrontal near-infrared spectroscopy (NIRS) parameters and high-frequency paired-pulse (PS100) evoked responses to electrical muscle stimulation were monitored. In experiment 2, 10 subjects performed another RCTE in SevHyp and Norm conditions in which the number of contractions, biceps brachii electromyography responses to electrical nerve stimulation (M wave), and transcranial magnetic stimulation responses (motor-evoked potentials, MEP, and cortical silent period, CSP) were recorded. Performance during RCTE was significantly reduced by 10-15% in SevHyp (arterial O(2) saturation, SpO(2) = ∼75%) compared with ModHyp (SpO(2) = ∼90%) or Norm/Hyper (SpO(2) > 97%). Performance reduction in SevHyp occurred despite similar 1) metabolic (muscle NIRS parameters) and functional (changes in PS100 and M wave) muscle states and 2) MEP and CSP responses, suggesting comparable corticospinal excitability and spinal and cortical inhibition between SevHyp and Norm. It is concluded that, in SevHyp, performance and central drive can be altered independently of afferent feedback and peripheral fatigue. It is concluded that submaximal performance in SevHyp is partly reduced by a mechanism related directly to brain oxygenation. PMID:22323647

  13. Performance level affects the dietary supplement intake of both individual and team sports athletes.

    PubMed

    Giannopoulou, Ifigenia; Noutsos, Kostantinos; Apostolidis, Nikolaos; Bayios, Ioannis; Nassis, George P

    2013-01-01

    Dietary supplement (DS) intake is high in elite level athletes, however few studies have investigated the impact that the performance level of the athletes has on supplementation intake in individual and team sports. The purpose of the study was to determine and compare the DS intake among individual and team sport athletes of various performance levels. A total of 2845 participants (athletes: 2783, controls: 62) between the ages of 11 and 44 years old participated in the study. A 3-page questionnaire was developed to assess the intake of DS. Athletes were categorized based on participation in individual (n = 775) and team sports (n = 2008). To assess the effect of performance level in supplementation intake, athletes were categorized based on training volume, participation in the national team, and winning at least one medal in provincial, national, international or Olympic games. Overall, 37% of all athletes of various performance levels reported taking at least one DS in the last month. A higher prevalence of DS intake was reported in individual (44%) compared to team sport athletes (35%) (p < 0.001). Athletes of high performance level reported greater DS intake compared to lower performance athletes. Males reported a significantly greater prevalence of DS intake compared to females. The most popular supplement reported was amino acid preparation with the main reason of supplementation being endurance improvements. In conclusion, performance level and type of sport appear to impact the DS practices of male and female athletes. These findings should be validated in other populations. Key points37% of Mediterranean athletes of various sports and levels have reported taking dietary supplements.The performance level of the athletes affects the dietary supplementation intake.Athletes in individual sports appear to have a higher DS intake compared to team sport athletes.Male athletes appear to take more dietary supplements compared to female athletes. PMID:24149744

  14. 40 CFR Table 3 to Subpart Mmmmm of... - Performance Test Requirements for New or Reconstructed Flame Lamination Affected Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... or Reconstructed Flame Lamination Affected Sources 3 Table 3 to Subpart MMMMM of Part 63 Protection... Lamination Affected Sources As stated in § 63.8800, you must comply with the requirements for performance tests for new or reconstructed flame lamination affected sources in the following table using...

  15. The Functional Effect of Teacher Positive and Neutral Affect on Task Performance of Students with Significant Disabilities

    ERIC Educational Resources Information Center

    Park, Sungho; Singer, George H. S.; Gibson, Mary

    2005-01-01

    The study uses an alternating treatment design to evaluate the functional effect of teacher's affect on students' task performance. Tradition in special education holds that teachers should engage students using positive and enthusiastic affect for task presentations and praise. To test this assumption, we compared two affective conditions. Three…

  16. Barbarea vulgaris Glucosinolate Phenotypes Differentially Affect Performance and Preference of Two Different Species of Lepidopteran Herbivores

    PubMed Central

    Vet, Louise E. M.; van der Putten, Wim H.; van Dam, Nicole M.

    2008-01-01

    The composition of secondary metabolites and the nutritional value of a plant both determine herbivore preference and performance. The genetically determined glucosinolate pattern of Barbarea vulgaris can be dominated by either glucobarbarin (BAR-type) or by gluconasturtiin (NAS-type). Because of the structural differences, these glucosinolates may have different effects on herbivores. We compared the two Barbarea chemotypes with regards to the preference and performance of two lepidopteran herbivores, using Mamestra brassicae as a generalist and Pieris rapae as a specialist. The generalist and specialist herbivores did not prefer either chemotype for oviposition. However, larvae of the generalist M. brassicae preferred to feed and performed best on NAS-type plants. On NAS-type plants, 100% of the M. brassicae larvae survived while growing exponentially, whereas on BAR-type plants, M. brassicae larvae showed little growth and a mortality of 37.5%. In contrast to M. brassicae, the larval preference and performance of the specialist P. rapae was unaffected by plant chemotype. Total levels of glucosinolates, water soluble sugars, and amino acids of B. vulgaris could not explain the poor preference and performance of M. brassicae on BAR-type plants. Our results suggest that difference in glucosinolate chemical structure is responsible for the differential effects of the B. vulgaris chemotypes on the generalist herbivore. Electronic supplementary material The online version of this article (doi:10.1007/s10886-007-9424-9) contains supplementary material, which is available to authorized users. PMID:18213497

  17. A Theoretical Structure of High School Concert Band Performance

    ERIC Educational Resources Information Center

    Bergee, Martin J.

    2015-01-01

    This study used exploratory (EFA) and confirmatory factor analysis (CFA) to verify a theoretical structure for high school concert band performance and to test that structure for viability, generality, and invariance. A total of 101 university students enrolled in two different bands rated two high school band performances (a "first"…

  18. How Does the Driver’s Perception Reaction Time Affect the Performances of Crash Surrogate Measures?

    PubMed Central

    Kuang, Yan; Qu, Xiaobo; Weng, Jinxian; Etemad-Shahidi, Amir

    2015-01-01

    With the merit on representing traffic conflict through examining the crash mechanism and causality proactively, crash surrogate measures have long been proposed and applied to evaluate the traffic safety. However, the driver’s Perception-Reaction Time (PRT), an important variable in crash mechanism, has not been considered widely into surrogate measures. In this regard, it is important to know how the PRT affects the performances of surrogate indicators. To this end, three widely used surrogate measures are firstly modified by involving the PRT into their crash mechanisms. Then, in order to examine the difference caused by the PRT, a comparative study is carried out on a freeway section of the Pacific Motorway, Australia. This result suggests that the surrogate indicators’ performances in representing rear-end crash risks are improved with the incorporating of the PRT for the investigated section. PMID:26398416

  19. Water molecules inside protein structure affect binding of monosaccharides with HIV-1 antibody 2G12.

    PubMed

    Ueno-Noto, Kaori; Takano, Keiko

    2016-10-01

    Water molecules inside biomolecules constitute integral parts of their structure and participate in the functions of the proteins. Some of the X-ray crystallographic data are insufficient for analyzing a series of ligand-protein complexes in the same condition. We theoretically investigated antibody binding abilities of saccharide ligands and the effects of the inner water molecules of ligand-antibody complexes. Classical molecular dynamics and quantum chemical simulations using a model with possible water molecules inside the protein were performed with saccharide ligands and Human Immunodeficiency Virus 1 neutralizing antibody 2G12 complexes to estimate how inner water molecules of the protein affect the dynamics of the complexes as well as the ligand-antibody interaction. Our results indicate the fact that d-fructose's strong affinity to the antibody was partly due to the good retentiveness of solvent water molecules of the ligand and its stability of the ligand's conformation and relative position in the active site. © 2016 Wiley Periodicals, Inc. PMID:27388036

  20. Individual Differences in School Mathematics Performance and Feelings of Difficulty: The Effects of Cognitive Ability, Affect, Age, and Gender.

    ERIC Educational Resources Information Center

    Efklides, Anastasia; Papadaki, Maria; Papantoniou, Georgia; Kiosseoglou, Gregoris

    1999-01-01

    Explores possible individual differences effects on school mathematics performance and feelings of difficulty (FOD) of 243 subjects, ages 13 to 15 years. Considers cognitive ability, affect, age, and gender. Finds that ability directly influenced performance whereas both ability and affect influenced FOD. Discusses the results. (CMK)

  1. Cognition-Based and Affect-Based Trust as Mediators of Leader Behavior Influences on Team Performance

    ERIC Educational Resources Information Center

    Schaubroeck, John; Lam, Simon S. K.; Peng, Ann Chunyan

    2011-01-01

    We develop a model in which cognitive and affective trust in the leader mediate the relationship between leader behavior and team psychological states that, in turn, drive team performance. The model is tested on a sample of 191 financial services teams in Hong Kong and the U.S. Servant leadership influenced team performance through affect-based…

  2. Ambient temperature: a factor affecting performance and physiological response of broiler chickens

    NASA Astrophysics Data System (ADS)

    Donkoh, A.

    1989-12-01

    An experiment was conducted to elucidate the influence of four constant ambient temperatures (20°, 25°, 30° and 35°C) on the performance and physiological reactions of male commercial broiler chicks from 3 to 7 weeks of age. A 12 h light-dark cycle was operated, while relative humidity and air circulation were not controlled. Exposure of broiler chickens to the 20°, 25°, 30° and 35°C treatments showed highly significant ( P<0.0001) depression in growth rate, food intake and efficiency of food utilization, and a significant increase in water consumption for the 30° and 35°C groups. Mortality was, however, not affected by the temperature treatments. Changes in physiological status, such as increased rectal temperatures, decreased concentration of red blood cells, haemoglobin, haematocrit, and total plasma protein were observed in birds housed in the higher temperature (30° and 35°C) environments. Moreover, in these broiler chickens, there was an increased blood glucose concentration and a decreased thyroid gland weight. These results indicate that continuous exposure of broiler chickens to high ambient temperatures markedly affects their performance and physiological response.

  3. Is Long-Term Structural Priming Affected by Patterns of Experience with Individual Verbs?

    ERIC Educational Resources Information Center

    Kaschak, Michael P.; Borreggine, Kristin L.

    2008-01-01

    Several recent papers have reported long-term structural priming effects in experiments where previous patterns of experience with the double object and prepositional object constructions are shown to affect later patterns of language production for those constructions. The experiments reported in this paper address the extent to which these…

  4. Factors Affecting Higher Order Thinking Skills of Students: A Meta-Analytic Structural Equation Modeling Study

    ERIC Educational Resources Information Center

    Budsankom, Prayoonsri; Sawangboon, Tatsirin; Damrongpanit, Suntorapot; Chuensirimongkol, Jariya

    2015-01-01

    The purpose of the research is to develop and identify the validity of factors affecting higher order thinking skills (HOTS) of students. The thinking skills can be divided into three types: analytical, critical, and creative thinking. This analysis is done by applying the meta-analytic structural equation modeling (MASEM) based on a database of…

  5. Red Color Light at Different Intensities Affects the Performance, Behavioral Activities and Welfare of Broilers.

    PubMed

    Senaratna, D; Samarakone, T S; Gunawardena, W W D A

    2016-07-01

    Red light (RL) marked higher weight gain (WG) and preference of broilers compared to other light colors. This study aimed to investigate how different intensities of RL affect the performance, behavior and welfare of broilers. RL treatments were T1 = high intensity (320 lux), T2 = medium intensity (20 lux); T3 = dim intensity (5 lux), T4 = control/white light at (20 lux) provided on 20L:4D schedule and T5 = negative control; 12 hours dark: 12 hours day light. Cobb strain broilers were used in a Complete Randomize Design with 6 replicates. WG, water/feed intake, feed conversion ratio (FCR), mortality, behavior and welfare were assessed. At 35 d, significantly (p<0.05) highest body weight (2,147.06 g±99) was recorded by T3. Lowest body weight (1,640.55 g±56) and FCR (1.34) were recorded by T5. Skin weight was the only carcass parameter showed a significant (p<0.05) influence giving the highest (56.2 g) and the lowest (12.6 g) values for T5 and T1 respectively. Reduced welfare status indicated by significantly (p<0.05) higher foot pad lesions, hock burns and breast blisters was found under T3, due to reduced expression of behavior. Highest walking (2.08%±1%) was performed under T1 in the evening during 29 to 35 days. Highest dust bathing (3.01%±2%) was performed in the morning during 22 to 28 days and highest bird interaction (BI) (4.87%±4%) was observed in the evening by T5 during 14 to 21 days. Light intensity×day session×age interaction was significantly (p<0.05) affected walking, dust bathing and BI. Light intensity significantly (p<0.05) affected certain behaviors such as lying, eating, drinking, standing, walking, preening while lying, wing/leg stretching, sleeping, dozing, BI, vocalization, idling. In conclusion, birds essentially required provision of light in the night for better performance. Exposed to 5 lux contributed to higher WG, potentially indicating compromised welfare status. Further researches are suggested to investigate RL intensity based

  6. Red Color Light at Different Intensities Affects the Performance, Behavioral Activities and Welfare of Broilers

    PubMed Central

    Senaratna, D.; Samarakone, T. S.; Gunawardena, W. W. D. A.

    2016-01-01

    Red light (RL) marked higher weight gain (WG) and preference of broilers compared to other light colors. This study aimed to investigate how different intensities of RL affect the performance, behavior and welfare of broilers. RL treatments were T1 = high intensity (320 lux), T2 = medium intensity (20 lux); T3 = dim intensity (5 lux), T4 = control/white light at (20 lux) provided on 20L:4D schedule and T5 = negative control; 12 hours dark: 12 hours day light. Cobb strain broilers were used in a Complete Randomize Design with 6 replicates. WG, water/feed intake, feed conversion ratio (FCR), mortality, behavior and welfare were assessed. At 35 d, significantly (p<0.05) highest body weight (2,147.06 g±99) was recorded by T3. Lowest body weight (1,640.55 g±56) and FCR (1.34) were recorded by T5. Skin weight was the only carcass parameter showed a significant (p<0.05) influence giving the highest (56.2 g) and the lowest (12.6 g) values for T5 and T1 respectively. Reduced welfare status indicated by significantly (p<0.05) higher foot pad lesions, hock burns and breast blisters was found under T3, due to reduced expression of behavior. Highest walking (2.08%±1%) was performed under T1 in the evening during 29 to 35 days. Highest dust bathing (3.01%±2%) was performed in the morning during 22 to 28 days and highest bird interaction (BI) (4.87%±4%) was observed in the evening by T5 during 14 to 21 days. Light intensity×day session×age interaction was significantly (p<0.05) affected walking, dust bathing and BI. Light intensity significantly (p<0.05) affected certain behaviors such as lying, eating, drinking, standing, walking, preening while lying, wing/leg stretching, sleeping, dozing, BI, vocalization, idling. In conclusion, birds essentially required provision of light in the night for better performance. Exposed to 5 lux contributed to higher WG, potentially indicating compromised welfare status. Further researches are suggested to investigate RL intensity based

  7. Relationship between Microtubule Network Structure and Intracellular Transport in Cultured Endothelial Cells Affected by Shear Stress

    NASA Astrophysics Data System (ADS)

    Kudo, Susumu; Ikezawa, Kenji; Ikeda, Mariko; Tanishita, Kazuo

    Endothelial cells (ECs) that line the inner surface of blood vessels are barriers to the transport of various substances into or from vessel walls, and are continuously exposed to shear stress induced by blood flow in vivo. Shear stress affects the cytoskeleton (e.g., microtubules, microfilaments, intermediate filaments), and affects the transport of macromolecules. Here, the relationship between the microtubule network structure and this transport process for albumin uptake within cultured aortic endothelial cells affected by shear stress was studied. Based on fluorescent images of albumin uptake obtained by using confocal laser scanning microscopy (CLSM), both the microtubule network and albumin uptake in ECs were disrupted by colchicine and were affected by shear stress loading.

  8. Measures of GCM Performance as Functions of Model Parameters Affecting Clouds and Radiation

    NASA Astrophysics Data System (ADS)

    Jackson, C.; Mu, Q.; Sen, M.; Stoffa, P.

    2002-05-01

    This abstract is one of three related presentations at this meeting dealing with several issues surrounding optimal parameter and uncertainty estimation of model predictions of climate. Uncertainty in model predictions of climate depends in part on the uncertainty produced by model approximations or parameterizations of unresolved physics. Evaluating these uncertainties is computationally expensive because one needs to evaluate how arbitrary choices for any given combination of model parameters affects model performance. Because the computational effort grows exponentially with the number of parameters being investigated, it is important to choose parameters carefully. Evaluating whether a parameter is worth investigating depends on two considerations: 1) does reasonable choices of parameter values produce a large range in model response relative to observational uncertainty? and 2) does the model response depend non-linearly on various combinations of model parameters? We have decided to narrow our attention to selecting parameters that affect clouds and radiation, as it is likely that these parameters will dominate uncertainties in model predictions of future climate. We present preliminary results of ~20 to 30 AMIPII style climate model integrations using NCAR's CCM3.10 that show model performance as functions of individual parameters controlling 1) critical relative humidity for cloud formation (RHMIN), and 2) boundary layer critical Richardson number (RICR). We also explore various definitions of model performance that include some or all observational data sources (surface air temperature and pressure, meridional and zonal winds, clouds, long and short-wave cloud forcings, etc...) and evaluate in a few select cases whether the model's response depends non-linearly on the parameter values we have selected.

  9. Nectar resource limitation affects butterfly flight performance and metabolism differently in intensive and extensive agricultural landscapes.

    PubMed

    Lebeau, Julie; Wesselingh, Renate A; Van Dyck, Hans

    2016-05-11

    Flight is an essential biological ability of many insects, but is energetically costly. Environments under rapid human-induced change are characterized by habitat fragmentation and may impose constraints on the energy income budget of organisms. This may, in turn, affect locomotor performance and willingness to fly. We tested flight performance and metabolic rates in meadow brown butterflies (Maniola jurtina) of two contrasted agricultural landscapes: intensively managed, nectar-poor (IL) versus extensively managed, nectar-rich landscapes (EL). Young female adults were submitted to four nectar treatments (i.e. nectar quality and quantity) in outdoor flight cages. IL individuals had better flight capacities in a flight mill and had lower resting metabolic rates (RMR) than EL individuals, except under the severest treatment. Under this treatment, RMR increased in IL individuals, but decreased in EL individuals; flight performance was maintained by IL individuals, but dropped by a factor 2.5 in EL individuals. IL individuals had more canalized (i.e. less plastic) responses relative to the nectar treatments than EL individuals. Our results show significant intraspecific variation in the locomotor and metabolic response of a butterfly to different energy income regimes relative to the landscape of origin. Ecophysiological studies help to improve our mechanistic understanding of the eco-evolutionary impact of anthropogenic environments on rare and widespread species. PMID:27147100

  10. Structural performance of two aerobrake hexagonal heat shield panel concepts

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Dyess, James W.

    1992-01-01

    Structural sizing and performance are presented for two structural concepts for an aerobrake hexagonal heat shield panel. One concept features a sandwich construction with an aluminum honeycomb core and thin quasi-isotropic graphite-epoxy face sheets. The other concept features a skin-rib isogrid construction with thin quasi-isotropic graphite-epoxy skins and graphite-epoxy ribs oriented at 0, +60, and -60 degs along the panel. Linear static, linear bifurcation buckling, and nonlinear static analyses were performed to compare the structural performance of the two panel concepts and assess their feasibility for a lunar transfer vehicle aerobrake application.

  11. Factors affecting the performance of microbial fuel cells for sulfur pollutants removal.

    PubMed

    Zhao, Feng; Rahunen, Nelli; Varcoe, John R; Roberts, Alexander J; Avignone-Rossa, Claudio; Thumser, Alfred E; Slade, Robert C T

    2009-03-15

    A microbial fuel cell (MFC) has been developed for removal of sulfur-based pollutants and can be used for simultaneous wastewater treatment and electricity generation. This fuel cell uses an activated carbon cloth+carbon fibre veil composite anode, air-breathing dual cathodes and the sulfate-reducing species Desulfovibrio desulfuricans. 1.16gdm(-3) sulfite and 0.97gdm(-3) thiosulfate were removed from the wastewater at 22 degrees C, representing sulfite and thiosulfate removal conversions of 91% and 86%, respectively. The anode potential was controlled by the concentration of sulfide in the compartment. The performance of the cathode assembly was affected by the concentration of protons in the cation-exchanging ionomer with which the electrocatalyst is co-bound at the three-phase (air, catalyst and support) boundary. PMID:19022647

  12. Motion and emotion: depression reduces psychomotor performance and alters affective movements in caregiving interactions

    PubMed Central

    Young, Katherine S.; Parsons, Christine E.; Stein, Alan; Kringelbach, Morten L.

    2015-01-01

    Background: Impaired social functioning is a well-established feature of depression. Evidence to date suggests that disrupted processing of emotional cues may constitute part of this impairment. Beyond processing of emotional cues, fluent social interactions require that people physically move in synchronized, contingent ways. Disruptions to physical movements are a diagnostic feature of depression (psychomotor disturbance) but have not previously been assessed in the context of social functioning. Here we investigated the impact of psychomotor disturbance in depression on physical responsive behavior in both an experimental and observational setting. Methods: In Experiment 1, we examined motor disturbance in depression in response to salient emotional sounds, using a laboratory-based effortful motor task. In Experiment 2, we explored whether psychomotor disturbance was apparent in real-life social interactions. Using mother-infant interactions as a model affective social situation, we compared physical behaviors of mothers with and without postnatal depression (PND). Results: We found impairments in precise, controlled psychomotor performance in adults with depression relative to healthy adults (Experiment 1). Despite this disruption, all adults showed enhanced performance following exposure to highly salient emotional cues (infant cries). Examining real-life interactions, we found differences in physical movements, namely reduced affective touching, in mothers with PND responding to their infants, compared to healthy mothers (Experiment 2). Conclusions: Together, these findings suggest that psychomotor disturbance may be an important feature of depression that can impair social functioning. Future work investigating whether improvements in physical movement in depression could have a positive impact on social interactions would be of much interest. PMID:25741255

  13. How do radiographic techniques affect mass lesion detection performance in digital mammography?

    NASA Astrophysics Data System (ADS)

    Huda, Walter; Ogden, Kent M.; Scalzetti, Ernest M.; Dudley, Eric F.; Dance, David R.

    2004-05-01

    We investigated how the x-ray tube kV and mAs affected the detection of simulated lesions with diameters between 0.24 and 12 mm. Digital mammograms were acquired with and without mass lesions, permitting a difference image to be generated corresponding to the lesion alone. Isolated digital lesions were added at a reduced intensity to non-lesion images, and used in Four-Alternate Forced Choice (4-AFC) experiments to determine the lesion intensity that corresponded to an accuracy of 92% (I92%). Values of I92% were determined at x-ray tube output values ranging from 40 to 120 mAs, and x-ray tube voltages ranging from 24 to 32 kV. For mass lesions larger than ~0.8 mm, there was no significant change in detection peformance with changing mAs. Doubling of the x-ray tube output from 60 to 120 mAs resulted in an average change in I92% of only +3.8%, whereas the Rose model of lesion detection predicts a reduction in the experimental value of I92% of -29%. For the 0.24 mm lesion, however, reducing the x-ray beam mAs from 100 to 40 mAs reduced the average detection performance by ~60%. Contrast-detail curves for lesions with diameter >= 0.8 mm had a slope of ~+0.23, whereas the Rose model predicts a slope of -0.5. For lesions smaller than ~0.8 mm, contrast-detail slopes were all negative with the average gradient increasing with decreasing mAs value. Increasing the x-ray tube voltage from 24 to 32 kV at a constant display contrast resulted in a modest improvement in low contrast lesion detection performance of ~10%. Increasing the display window width from 2000 to 2500 reduced the average observer performance by ~6%. Our principal finding is that radiographic technique factors have little effect on detection performance for lesions larger than ~0.8 mm, but that the visibility of smaller lesions is affected by quantum mottle in qualitative agreement with the predictions of the Rose model.

  14. Personality Traits Affect Teaching Performance of Attending Physicians: Results of a Multi-Center Observational Study

    PubMed Central

    Scheepers, Renée A.; Lombarts, Kiki M. J. M. H.; van Aken, Marcel A. G.; Heineman, Maas Jan; Arah, Onyebuchi A.

    2014-01-01

    Background Worldwide, attending physicians train residents to become competent providers of patient care. To assess adequate training, attending physicians are increasingly evaluated on their teaching performance. Research suggests that personality traits affect teaching performance, consistent with studied effects of personality traits on job performance and academic performance in medicine. However, up till date, research in clinical teaching practice did not use quantitative methods and did not account for specialty differences. We empirically studied the relationship of attending physicians' personality traits with their teaching performance across surgical and non-surgical specialties. Method We conducted a survey across surgical and non-surgical specialties in eighteen medical centers in the Netherlands. Residents evaluated attending physicians' overall teaching performance, as well as the specific domains learning climate, professional attitude, communication, evaluation, and feedback, using the validated 21-item System for Evaluation of Teaching Qualities (SETQ). Attending physicians self-evaluated their personality traits on a 5-point scale using the validated 10-item Big Five Inventory (BFI), yielding the Five Factor model: extraversion, conscientiousness, neuroticism, agreeableness and openness. Results Overall, 622 (77%) attending physicians and 549 (68%) residents participated. Extraversion positively related to overall teaching performance (regression coefficient, B: 0.05, 95% CI: 0.01 to 0.10, P = 0.02). Openness was negatively associated with scores on feedback for surgical specialties only (B: −0.10, 95% CI: −0.15 to −0.05, P<0.001) and conscientiousness was positively related to evaluation of residents for non-surgical specialties only (B: 0.13, 95% CI: 0.03 to 0.22, p = 0.01). Conclusions Extraverted attending physicians were consistently evaluated as better supervisors. Surgical attending physicians who display high levels of

  15. Performance comparison of structural stormwater best management practices.

    PubMed

    Barrett, Michael E

    2005-01-01

    This paper describes a method for comparing the pollutant removal of a number of structural stormwater treatment devices, commonly referred to as best management practices (BMPs). Historically, the pollutant removal ability of a BMP has been expressed as a percent reduction in concentration or load. Unfortunately, the calculated percent reduction in pollutant concentration is strongly affected by the influent concentration, with the calculated reduction generally being much lower when the event mean concentrations (EMCs) in the untreated runoff from the test watershed are low. The objective of the proposed methodology is to eliminate this problem by predicting BMP performance for an arbitrary influent concentration, so that BMPs evaluated in different watersheds can be compared as if the influent quality at all sites were the same. This method allows BMPs to be compared based on the quality of effluent produced and the mass reduction. The proposed method uses linear regression as the primary tool to compute the expected effluent concentration from a BMP, given a specific influent concentration of interest and was developed using data collected in the California Department of Transportation BMP Retrofit Pilot Program. This technique reveals that for media filters, the concentration of sediment and other particle-associated pollutants in treated runoff is generally unrelated to influent quality and is relatively constant. Wet basins with large permanent pool volumes also have effluent concentrations that are constant for most constituents and unrelated to influent concentrations. In these situations, the "percent reduction" in a pollutant EMC is not an inherent characteristic of the BMP, but a function of the influent EMC, because the quality of effluent produced is constant. Predicting the effluent quality of several types of conventional BMPs based on a common influent concentration allows an objective comparison of their performance and the selection of a BMP that

  16. The effects of activity-elicited humor and group structure on group cohesion and affective responses.

    PubMed

    Banning, M R; Nelson, D L

    1987-08-01

    The ability to analyze the therapeutic components of an activity is an important skill for occupational therapists. This study examined two potentially significant factors in activity analysis: the use of humor and the effect of group structure. Four groups (two with a parallel structure and two with a project structure) participated in a hat-making activity designed to elicit humor. Four groups (two with a parallel structure and two with a project structure) participated in a bookmark-making activity. The 28 female subjects' affective responses were measured by Osgood's short-form semantic differential, and the cohesion among group members was assessed by the Group Environment Scale. Results indicated that subjects who participated in groups which included humor rated their activity significantly higher on two factors of affective meaning (evaluation and action) and significantly higher in terms of cohesion. There was a significant interaction between the two activities and group structure in terms of the action factor and cohesion. In both cases the parallel groups making bookmarks received particularly low scores. The findings have implications for conceptualizing occupational therapy group activities. PMID:3434603

  17. Landscape structure affects specialists but not generalists in naturally fragmented grasslands.

    PubMed

    Miller, Jesse E D; Damschen, Ellen I; Harrison, Susan P; Grace, James B

    2015-12-01

    Understanding how biotic communities respond to landscape spatial structure is critically important for conservation management as natural habitats become increasingly fragmented. However, empirical studies of the effects of spatial structure on plant species richness have found inconsistent results, suggesting that more comprehensive approaches are needed. We asked how landscape structure affects total plant species richness and the richness of a guild of specialized plants in a multivariate context. We sampled herbaceous plant communities at 56 dolomite glades (insular, fire-adapted grasslands) across the Missouri Ozarks, USA, and used structural equation modeling (SEM) to analyze the relative importance of landscape structure, soil resource availability, and fire history for plant communities. We found that landscape spatial structure, defined as the area-weighted proximity of glade habitat surrounding study sites (proximity index), had a significant effect on total plant species richness, but only after we controlled for environmental covariates. Richness of specialist species, but not generalists, was positively related to landscape spatial structure. Our results highlight that local environmental filters must be considered to understand the influence of landscape structure on communities and that unique species guilds may respond differently to landscape structure than the community as a whole. These findings suggest that both local environment and landscape context should be considered when developing management strategies for species of conservation concern in fragmented habitats. PMID:26909437

  18. Landscape structure affects specialists but not generalists in naturally fragmented grasslands

    USGS Publications Warehouse

    Miller, Jesse E.D.; Damschen, Ellen Ingman; Harrison, Susan P.; Grace, James B.

    2015-01-01

    Understanding how biotic communities respond to landscape spatial structure is critically important for conservation management as natural landscapes become increasingly fragmented. However, empirical studies of the effects of spatial structure on plant species richness have found inconsistent results, suggesting that more comprehensive approaches are needed. In this study, we asked how landscape structure affects total plant species richness and the richness of a guild of specialized plants in a multivariate context. We sampled herbaceous plant communities at 56 dolomite glades (insular, fire-adapted grasslands) across the Missouri Ozarks, and used structural equation modeling (SEM) to analyze the relative importance of landscape structure, soil resource availability, and fire history for plant communities. We found that landscape spatial structure-defined as the area-weighted proximity of glade habitat surrounding study sites (proximity index)-had a significant effect on total plant species richness, but only after we controlled for environmental covariates. Richness of specialist species, but not generalists, was positively related to landscape spatial structure. Our results highlight that local environmental filters must be considered to understand the influence of landscape structure on communities, and that unique species guilds may respond differently to landscape structure than the community as a whole. These findings suggest that both local environment and landscape context should be considered when developing management strategies for species of conservation concern in fragmented habitats.

  19. High performance hybrid magnetic structure for biotechnology applications

    DOEpatents

    Humphries, David E.; Pollard, Martin J.; Elkin, Christopher J.

    2009-02-03

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are further improvements to aspects of the hybrid magnetic structure, including additional elements and for adapting the use of the hybrid magnetic structure for use in biotechnology and high throughput processes.

  20. High performance hybrid magnetic structure for biotechnology applications

    DOEpatents

    Humphries, David E.; Pollard, Martin J.; Elkin, Christopher J.

    2006-12-12

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

  1. High performance hybrid magnetic structure for biotechnology applications

    DOEpatents

    Humphries, David E; Pollard, Martin J; Elkin, Christopher J

    2005-10-11

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

  2. Global self-esteem in relation to structural models of personality and affectivity.

    PubMed

    Watson, David; Suls, Jerry; Haig, Jeffrey

    2002-07-01

    Three studies examined global self-esteem in relation to structural models of personality and affectivity. In every study, self-esteem was strongly negatively correlated with Neuroticism/Negative Affectivity and moderately to strongly related to Extraversion/Positive Affectivity. Additional findings, however, revealed that self-esteem is better viewed at the lower order level. For instance, global self-esteem correlated -.79 with the Depression facet of the Revised NEO Personality Inventory (P. T. Costa, Jr., & R. R. McCrae, 1992) in Study 3. Moreover, confirmatory factor analyses produced very strong correlations between self-esteem and depression in both Study 2 (r = -.82) and Study 3 (r = -.86). Taken together, the data suggest that global self-esteem measures define one end of a bipolar continuum, with trait indicators of depression defining the other. PMID:12088125

  3. Electroosmotic pump performance is affected by concentration polarizations of both electrodes and pump

    PubMed Central

    Suss, Matthew E.; Mani, Ali; Zangle, Thomas A.; Santiago, Juan G.

    2010-01-01

    Current methods of optimizing electroosmotic (EO) pump performance include reducing pore diameter and reducing ionic strength of the pumped electrolyte. However, these approaches each increase the fraction of total ionic current carried by diffuse electric double layer (EDL) counterions. When this fraction becomes significant, concentration polarization (CP) effects become important, and traditional EO pump models are no longer valid. We here report on the first simultaneous concentration field measurements, pH visualizations, flow rate, and voltage measurements on such systems. Together, these measurements elucidate key parameters affecting EO pump performance in the CP dominated regime. Concentration field visualizations show propagating CP enrichment and depletion fronts sourced by our pump substrate and traveling at order mm/min velocities through millimeter-scale channels connected serially to our pump. The observed propagation in millimeter-scale channels is not explained by current propagating CP models. Additionally, visualizations show that CP fronts are sourced by and propagate from the electrodes of our system, and then interact with the EO pump-generated CP zones. With pH visualizations, we directly detect that electrolyte properties vary sharply across the anode enrichment front interface. Our observations lead us to hypothesize possible mechanisms for the propagation of both pump- and electrode-sourced CP zones. Lastly, our experiments show the dynamics associated with the interaction of electrode and membrane CP fronts, and we describe the effect of these phenomena on EO pump flow rates and applied voltages under galvanostatic conditions. PMID:21516230

  4. Factors affecting the stability and performance of ipratropium bromide; fenoterol hydrobromide pressurized-metered dose inhalers.

    PubMed

    Ninbovorl, Jenjira; Sawatdee, Somchai; Srichana, Teerapol

    2013-12-01

    The aim of the study was to investigate the factors affecting the stability and performance of ipratropium bromide and fenoterol hydrobromide in a pressurized-metered dose inhaler (pMDI). A factorial design was applied to investigate the effects of three parameters (propellant, water, and ethanol) on the performance of 27 designed formulations of a solution-based pMDI. The formulations that contained a hydrofluoroalkane (HFA) propellant lower than 72% v/v and an ethanol concentration higher than 27% v/v remained as clear solutions. Nine formulations that contained the HFA propellant higher than 74% v/v precipitated. The results indicated that it was not only the HFA propellant content of the formulations that was related to the formulation instability but also ethanol content. Only six formulations from the 18 formulations, that did not precipitate, produced drug contents that were within the acceptable range (80-120%). These six formulations generated aerosols with mass median aerodynamic diameters (MMAD) of approximately 2 μm with a fine particle fraction (FPF; particle size, <6.4 μm) between 45% and 52%. The MMAD and FPF did not change significantly after 6 months of storage (P > 0.05). PMID:23975571

  5. Computer-Detected Attention Affects Foreign Language Listening but Not Reading Performance.

    PubMed

    Lee, Shu-Ping

    2016-08-01

    No quantitative study has explored the influence of attention on learning English as a foreign language (EFL). This study investigated whether computer-detected attention is associated with EFL reading and listening and reading and listening anxiety. Traditional paper-based English tests used as entrance examinations and tests of general trait anxiety, reading, listening, reading test state anxiety, and listening test state anxiety were administered in 252 Taiwan EFL college students who were divided into High Attention (Conners' Continuous Performance Test, CPT < 50) and Low Attention (CPT ≥ 50) groups. No differences were found between the two groups for traditional paper-based English tests, trait anxieties, general English reading anxiety scales, and general English listening anxiety scales. The Low Attention group had higher test state anxiety and lower listening test scores than the High Attention group, but not in reading. State anxiety during listening tests for EFL students with computer-detected low attention tendency was elevated and their EFL listening performance was affected, but those differences were not found in reading. PMID:27371638

  6. Factors affecting numerical typing performance of young adults in a hear-and-type task.

    PubMed

    Lin, Cheng-Jhe; Wu, Changxu

    2011-12-01

    Numerical hear-and-type tasks, i.e. making immediate keypresses according to verbally presented numbers, possess both practical and theoretical importance but received relatively little attention. Effects of speech rates (500-ms vs. 1000-ms interval), urgency (urgent condition: performance-based monetary incentive plus time limit vs. non-urgent condition: flat-rate compensation) and finger strategies (single vs. multi-finger typing) on typing speed and accuracy were investigated. Fast speech rate and multi-finger typing produced more errors and slower typing speed. Urgency improved typing speed but decreased accuracy. Errors were almost doubled under urgent condition, while urgency effect on speed was similar to that of speech rate. Examination of error patterns did not fully support Salthouse's (1986) speculations about error-making mechanisms. The results implied that urgency could play a more important role in error-making than task demands. Numerical keyboard design and error detection could benefit from spatial incidence of errors found in this study. STATEMENT OF RELEVANCE: This study revealed that classic speculations about error-making mechanisms in alphabetical typing do not necessarily translate to numerical typing. Factors other than external task demands such as urgency can affect typing performance to a similar or greater extent. Investigations of intrinsic error-making factors in non-traditional typing tasks are encouraged. PMID:22103724

  7. The structure and size of sensory bursts encode stimulus information but only size affects behavior.

    PubMed

    Marsat, Gary; Pollack, Gerald S

    2010-04-01

    Cricket ultrasound avoidance is a classic model system for neuroethology. Avoidance steering is triggered by high-firing-rate bursts of spikes in the auditory command neuron AN2. Although bursting is common among sensory neurons, and although the detailed structure of bursts may encode information about the stimulus, it is as yet unclear whether this information is decoded. We address this question in two ways: from an information coding point of view, by showing the relationship between stimulus and burst structure; and also from a functional point of view by showing the relationship between burst structure and behavior. We conclude that the burst structure carries detailed temporal information about the stimulus but that this has little impact on the behavioral response, which is affected mainly by burst size. PMID:20213110

  8. Full-scale experimental and numerical study about structural behaviour of a thin-walled cold-formed steel building affected by ground settlements due to land subsidence

    NASA Astrophysics Data System (ADS)

    Ortiz, J. A.; Hernández, L. A.; Hernández, M.; Pacheco, J.; Zermeño, M. E.; Salinas, R.

    2015-11-01

    Land subsidence due to ground water withdrawal is a problem in many places around the world (Poland, 1984). This causes differential ground settlements that affect masonry structures, because these structural materials do not exhibit an adequate performance beyond a certain level of angular distortion. This work presents the experimental and numerical results about a study regarding the performance of a full-scale thin-walled cold-formed steel building affected by ground differential settlements due to land subsidence. The experimental stage consisted in the construction of a test-building to be subjected to differential settlements in laboratory. The numerical stage consisted in performing a numerical non-linear static pull-down analysis simulating the differential ground settlements of the test-building. The results show that the structural performance of the tested building was very suitable in terms of ductility.

  9. Familiarity affects social network structure and discovery of prey patch locations in foraging stickleback shoals

    PubMed Central

    Atton, N.; Galef, B. J.; Hoppitt, W.; Webster, M. M.; Laland, K. N.

    2014-01-01

    Numerous factors affect the fine-scale social structure of animal groups, but it is unclear how important such factors are in determining how individuals encounter resources. Familiarity affects shoal choice and structure in many social fishes. Here, we show that familiarity between shoal members of sticklebacks (Gasterosteus aculeatus) affects both fine-scale social organization and the discovery of resources. Social network analysis revealed that sticklebacks remained closer to familiar than to unfamiliar individuals within the same shoal. Network-based diffusion analysis revealed that there was a strong untransmitted social effect on patch discovery, with individuals tending to discover a task sooner if a familiar individual from their group had previously done so than if an unfamiliar fish had done so. However, in contrast to the effect of familiarity, the frequency with which individuals had previously associated with one another had no effect upon the likelihood of prey patch discovery. This may have been due to the influence of fish on one another's movements; the effect of familiarity on discovery of an empty ‘control’ patch was as strong as for discovery of an actual prey patch. Our results demonstrate that factors affecting fine-scale social interactions can also influence how individuals encounter and exploit resources. PMID:25009061

  10. Creating Masterpieces: How Course Structures and Routines Enable Student Performance

    ERIC Educational Resources Information Center

    Dean, Kathy Lund; Fornaciari, Charles J.

    2014-01-01

    Over a five-year period, we made a persistent observation: Course structures and routines, such as assignment parameters, student group process rules, and grading schemes were being consistently ignored. As a result, we got distracted by correcting these structural issues and were spending less time on student assignment performance. In this…

  11. Protein Molecular Structures, Protein SubFractions, and Protein Availability Affected by Heat Processing: A Review

    SciTech Connect

    Yu,P.

    2007-01-01

    The utilization and availability of protein depended on the types of protein and their specific susceptibility to enzymatic hydrolysis (inhibitory activities) in the gastrointestine and was highly associated with protein molecular structures. Studying internal protein structure and protein subfraction profiles leaded to an understanding of the components that make up a whole protein. An understanding of the molecular structure of the whole protein was often vital to understanding its digestive behavior and nutritive value in animals. In this review, recently obtained information on protein molecular structural effects of heat processing was reviewed, in relation to protein characteristics affecting digestive behavior and nutrient utilization and availability. The emphasis of this review was on (1) using the newly advanced synchrotron technology (S-FTIR) as a novel approach to reveal protein molecular chemistry affected by heat processing within intact plant tissues; (2) revealing the effects of heat processing on the profile changes of protein subfractions associated with digestive behaviors and kinetics manipulated by heat processing; (3) prediction of the changes of protein availability and supply after heat processing, using the advanced DVE/OEB and NRC-2001 models, and (4) obtaining information on optimal processing conditions of protein as intestinal protein source to achieve target values for potential high net absorbable protein in the small intestine. The information described in this article may give better insight in the mechanisms involved and the intrinsic protein molecular structural changes occurring upon processing.

  12. Factors affecting the performance of community health workers in India: a multi-stakeholder perspective

    PubMed Central

    Sharma, Reetu; Webster, Premila; Bhattacharyya, Sanghita

    2014-01-01

    Background Community health workers (CHWs) form a vital link between the community and the health department in several countries. In India, since 2005 this role is largely being played by Accredited Social Health Activists (ASHAs), who are village-level female workers. Though ASHAs primarily work for the health department, in a model being tested in Rajasthan they support two government departments. Focusing on the ASHA in this new role as a link worker between two departments, this paper examines factors associated with her work performance from a multi-stakeholder perspective. Design The study was done in 16 villages from two administrative blocks of Udaipur district in Rajasthan. The findings are based on 63 in-depth interviews with ASHAs, their co-workers and representatives from the two departments. The interviews were conducted using interview guides. An inductive approach with open coding was used for manual data analysis. Results This study shows that an ASHA's motivation and performance are affected by a variety of factors that emerge from the complex context in which she works. These include various personal (e.g. education), professional (e.g. training, job security), and organisational (e.g. infrastructure) factors along with others that emerge from external work environment. The participants suggested various ways to address these challenges. Conclusion In order to improve the performance of ASHAs, apart from taking corrective actions at the professional and organisational front on a priority basis, it is equally essential to promote cordial work relationships amongst ASHAs and other community-level workers from the two departments. This will also have a positive impact on community health. PMID:25319596

  13. How does performance of ultrasound tissue typing affect design of prostate IMRT dose-painting protocols?

    SciTech Connect

    Zhang Pengpeng . E-mail: pz2010@columbia.edu; Osterman, K. Sunshine; Liu Tian; Li Xiang; Kessel, Jack; Wu, Leester; Schiff, Peter; Kutcher, Gerald J.

    2007-02-01

    Purpose: To investigate how the performance characteristics of ultrasound tissue typing (UTT) affect the design of a population-based prostate dose-painting protocol. Methods and Materials: The performance of UTT is evaluated using the receiver operating characteristic curve. As the imager's sensitivity increases, more tumors are detected, but the specificity worsens, causing more false-positive results. The UTT tumor map, obtained with a specific sensitivity and specificity setup, was used with the patient's CT image to guide intensity-modulated radiotherapy (IMRT) planning. The optimal escalation dose to the UTT positive region, as well as the safe dose to the negative background, was obtained by maximizing the uncomplicated control (i.e., a combination of tumor control probability and weighted normal tissue complication probability). For high- and low-risk tumors, IMRT plans guided by conventional ultrasound or UTT with a one-dimensional or two-dimensional spectrum analysis technique were compared with an IMRT plan in which the whole prostate was dose escalated. Results: For all imaging modalities, the specificity of 0.9 was chosen to reduce complications resulting from high false-positive results. If the primary tumors were low risk, the IMRT plans guided by all imaging modalities achieved high tumor control probability and reduced the normal tissue complication probability significantly compared with the plan with whole gland dose escalation. However, if the primary tumors were high risk, the accuracy of the imaging modality was critical to maintain the tumor control probability and normal tissue complication probability at acceptable levels. Conclusion: The performance characteristics of an imager have important implications in dose painting and should be considered in the design of dose-painting protocols.

  14. Why does offspring size affect performance? Integrating metabolic scaling with life-history theory.

    PubMed

    Pettersen, Amanda K; White, Craig R; Marshall, Dustin J

    2015-11-22

    Within species, larger offspring typically outperform smaller offspring. While the relationship between offspring size and performance is ubiquitous, the cause of this relationship remains elusive. By linking metabolic and life-history theory, we provide a general explanation for why larger offspring perform better than smaller offspring. Using high-throughput respirometry arrays, we link metabolic rate to offspring size in two species of marine bryozoan. We found that metabolism scales allometrically with offspring size in both species: while larger offspring use absolutely more energy than smaller offspring, larger offspring use proportionally less of their maternally derived energy throughout the dependent, non-feeding phase. The increased metabolic efficiency of larger offspring while dependent on maternal investment may explain offspring size effects-larger offspring reach nutritional independence (feed for themselves) with a higher proportion of energy relative to structure than smaller offspring. These findings offer a potentially universal explanation for why larger offspring tend to perform better than smaller offspring but studies on other taxa are needed. PMID:26559952

  15. Structural and Convergent Validity of the Homework Performance Questionnaire

    ERIC Educational Resources Information Center

    Pendergast, Laura L.; Watkins, Marley W.; Canivez, Gary L.

    2014-01-01

    Homework is a requirement for most school-age children, but research on the benefits and drawbacks of homework is limited by lack of psychometrically sound measurement of homework performance. This study examined the structural and convergent validity of scores from the newly developed Homework Performance Questionnaire -- Teacher Scale (HPQ-T).…

  16. Self-Evaluation Accuracy and Satisfaction with Performance: Are there Affective Costs or Benefits of Positive Self-Evaluation Bias?

    ERIC Educational Resources Information Center

    Narciss, Susanne; Koerndle, Hermann; Dresel, Markus

    2011-01-01

    This paper examines how self-evaluation biases may influence satisfaction with performance. A review of theoretical positions suggests there are two views, both of which are supported by studies involving laboratory tasks. The first view predicts affective costs, and the second affective benefits of positive self-evaluation bias. We test the…

  17. Exogenous lactate supply affects lactate kinetics of rainbow trout, not swimming performance

    PubMed Central

    Omlin, Teye; Langevin, Karolanne

    2014-01-01

    Intense swimming causes circulatory lactate accumulation in rainbow trout because lactate disposal (Rd) is not stimulated as strongly as lactate appearance (Ra). This mismatch suggests that maximal Rd is limited by tissue capacity to metabolize lactate. This study uses exogenous lactate to investigate what constrains maximal Rd and minimal Ra. Our goals were to determine how exogenous lactate affects: 1) Ra and Rd of lactate under baseline conditions or during graded swimming, and 2) exercise performance (critical swimming speed, Ucrit) and energetics (cost of transport, COT). Results show that exogenous lactate allows swimming trout to boost maximal Rd lactate by 40% and reach impressive rates of 56 μmol·kg−1·min−1. This shows that the metabolic capacity of tissues for lactate disposal is not responsible for setting the highest Rd normally observed after intense swimming. Baseline endogenous Ra (resting in normoxic water) is not significantly reduced by exogenous lactate supply. Therefore, trout have an obligatory need to produce lactate, either as a fuel for oxidative tissues and/or from organs relying on glycolysis. Exogenous lactate does not affect Ucrit or COT, probably because it acts as a substitute for glucose and lipids rather than extra fuel. We conclude that the observed 40% increase in Rd lactate is made possible by accelerating lactate entry into oxidative tissues via monocarboxylate transporters (MCTs). This observation together with the weak expression of MCTs and the phenomenon of white muscle lactate retention show that lactate metabolism of rainbow trout is significantly constrained by transmembrane transport. PMID:25121611

  18. Hemodynamic and affective correlates assessed during performance on the Columbia card task (CCT).

    PubMed

    Holper, Lisa; Murphy, Ryan O

    2014-12-01

    The study aimed to test the potential of functional near-infrared spectroscopy (fNIRS) in combination with electrodermal activity (EDA) in a decision paradigm by means of the Columbia card task (CCT). The CCT is a dynamic decision task characterized by assessing subjects' risk-taking via eliciting voluntary stopping points in a series of incrementally increasingly risky choices. Using the combined fNIRS-EDA approach, we aim to examine the hemodynamic and affective correlates of both decision and outcome responses during performance on the CCT. Twenty healthy subjects completed the Cold and Hot CCT version while fNIRS over prefrontal cortex and EDA were recorded. Results showed that (1) in the decision phase fNIRS revealed larger total hemoglobin concentration changes [tHb] in the Cold as compared to the Hot CCT, whereas EDA revealed an opposite pattern with larger skin conductance responses (SCRs) to the Hot as compared to the Cold CCT. (2) No significant [tHb] signals or SCRs were found in the outcome phase. (3) Coherence calculations between fNIRS and EDA in the heart rate frequency showed a significant increase during the Hot as compared to the Cold CCT. Our findings designate fNIRS as suitable tool for monitoring decision-making processes. The combination of fNIRS and EDA demonstrates the potential of simultaneously assessing the interaction between hemodynamic and affective responses which can provide additional information concerning the relationship between these two physiological systems for various research areas. PMID:24242358

  19. Affective Factors in the Mediation of Background Effects on Cognitive Performance.

    ERIC Educational Resources Information Center

    Cuttance, Peter F.

    1980-01-01

    Academic achievement at age 16 was influenced more by achievement at age 14 than by affective variables. Affective variables included academic and occupational aspiration, parent expectations, school attitudes, sex, socioeconomic status, parents' education, and migrancy. (CP)

  20. Total systems design analysis of high performance structures

    NASA Technical Reports Server (NTRS)

    Verderaime, V.

    1993-01-01

    Designer-control parameters were identified at interdiscipline interfaces to optimize structural systems performance and downstream development and operations with reliability and least life-cycle cost. Interface tasks and iterations are tracked through a matrix of performance disciplines integration versus manufacturing, verification, and operations interactions for a total system design analysis. Performance integration tasks include shapes, sizes, environments, and materials. Integrity integrating tasks are reliability and recurring structural costs. Significant interface designer control parameters were noted as shapes, dimensions, probability range factors, and cost. Structural failure concept is presented, and first-order reliability and deterministic methods, benefits, and limitations are discussed. A deterministic reliability technique combining benefits of both is proposed for static structures which is also timely and economically verifiable. Though launch vehicle environments were primarily considered, the system design process is applicable to any surface system using its own unique filed environments.

  1. Small but Powerful: Top Predator Local Extinction Affects Ecosystem Structure and Function in an Intermittent Stream

    PubMed Central

    Rodríguez-Lozano, Pablo; Verkaik, Iraima; Rieradevall, Maria; Prat, Narcís

    2015-01-01

    Top predator loss is a major global problem, with a current trend in biodiversity loss towards high trophic levels that modifies most ecosystems worldwide. Most research in this area is focused on large-bodied predators, despite the high extinction risk of small-bodied freshwater fish that often act as apex consumers. Consequently, it remains unknown if intermittent streams are affected by the consequences of top-predators’ extirpations. The aim of our research was to determine how this global problem affects intermittent streams and, in particular, if the loss of a small-bodied top predator (1) leads to a ‘mesopredator release’, affects primary consumers and changes whole community structures, and (2) triggers a cascade effect modifying the ecosystem function. To address these questions, we studied the top-down effects of a small endangered fish species, Barbus meridionalis (the Mediterranean barbel), conducting an enclosure/exclosure mesocosm experiment in an intermittent stream where B. meridionalis became locally extinct following a wildfire. We found that top predator absence led to ‘mesopredator release’, and also to ‘prey release’ despite intraguild predation, which contrasts with traditional food web theory. In addition, B. meridionalis extirpation changed whole macroinvertebrate community composition and increased total macroinvertebrate density. Regarding ecosystem function, periphyton primary production decreased in apex consumer absence. In this study, the apex consumer was functionally irreplaceable; its local extinction led to the loss of an important functional role that resulted in major changes to the ecosystem’s structure and function. This study evidences that intermittent streams can be affected by the consequences of apex consumers’ extinctions, and that the loss of small-bodied top predators can lead to large ecosystem changes. We recommend the reintroduction of small-bodied apex consumers to systems where they have been

  2. Small but powerful: top predator local extinction affects ecosystem structure and function in an intermittent stream.

    PubMed

    Rodríguez-Lozano, Pablo; Verkaik, Iraima; Rieradevall, Maria; Prat, Narcís

    2015-01-01

    Top predator loss is a major global problem, with a current trend in biodiversity loss towards high trophic levels that modifies most ecosystems worldwide. Most research in this area is focused on large-bodied predators, despite the high extinction risk of small-bodied freshwater fish that often act as apex consumers. Consequently, it remains unknown if intermittent streams are affected by the consequences of top-predators' extirpations. The aim of our research was to determine how this global problem affects intermittent streams and, in particular, if the loss of a small-bodied top predator (1) leads to a 'mesopredator release', affects primary consumers and changes whole community structures, and (2) triggers a cascade effect modifying the ecosystem function. To address these questions, we studied the top-down effects of a small endangered fish species, Barbus meridionalis (the Mediterranean barbel), conducting an enclosure/exclosure mesocosm experiment in an intermittent stream where B. meridionalis became locally extinct following a wildfire. We found that top predator absence led to 'mesopredator release', and also to 'prey release' despite intraguild predation, which contrasts with traditional food web theory. In addition, B. meridionalis extirpation changed whole macroinvertebrate community composition and increased total macroinvertebrate density. Regarding ecosystem function, periphyton primary production decreased in apex consumer absence. In this study, the apex consumer was functionally irreplaceable; its local extinction led to the loss of an important functional role that resulted in major changes to the ecosystem's structure and function. This study evidences that intermittent streams can be affected by the consequences of apex consumers' extinctions, and that the loss of small-bodied top predators can lead to large ecosystem changes. We recommend the reintroduction of small-bodied apex consumers to systems where they have been extirpated, to restore

  3. Laying performance and egg quality of blue-shelled layers as affected by different housing systems.

    PubMed

    Wang, X L; Zheng, J X; Ning, Z H; Qu, L J; Xu, G Y; Yang, N

    2009-07-01

    Blue-shelled eggs are gaining popularity as the consumption demand diversifies in some countries. This study was carried out to investigate the laying performance and egg quality of the blue-shelled egg layers as well as the effects of different housing systems on egg production and quality traits. One thousand pullets from Dongxiang blue-shelled layers were divided into 2 even groups and kept in different housing systems (outdoor vs. cage). Daily laying performance was recorded from 20 to 60 wk of age. External and internal egg quality traits were examined at 26, 34, 42, and 50 wk. Yolk cholesterol concentration and whole egg cholesterol content were measured at 40 wk of age. Average laying rate from 20 to 60 wk for the cage (54.7%) was significantly higher than that of outdoor layers (39.3%). Among all of the egg quality traits, only eggshell color was affected by housing system. Interaction between housing system and layer age was found in egg weight, eggshell color, eggshell ratio, yolk color, and yolk weight. Meanwhile, cholesterol concentration in yolk was 8.64 +/- 0.40 mg/g in the outdoor eggs, which was significantly lower than that of eggs from the cage birds (10.32 +/- 0.48 mg/g; P < 0.05). Whole egg cholesterol content in the outdoor eggs (125.23 +/- 6.32 mg/egg) was also significantly lower than that of eggs from the caged layers (158.01 +/- 8.62 mg/egg). The results demonstrated that blue-shelled layers have lower productivity in the outdoor system than in the cage system. Blue-shelled layers have lower egg weight, larger yolk proportion, and lower cholesterol content compared with commercial layers. In a proper marketing system, lower productivity could be balanced by a higher price for the better quality of blue-shelled eggs. PMID:19531721

  4. Performing the Bakla in The Care Divas: Crossdressing, Affective Labor, and the Glimpse of the Cosmopolitan.

    PubMed

    Tiatco, Anril Pineda

    2015-01-01

    This essay is a close reading of The Care Divas, a Filipino musical revolving around the struggle of five Filipino caregivers in Israel who also struggle with their sexual identities as bakla (Filipino homosexual). The analysis is both an affirmation and a critique of the performance. In the affirmation, the musical is argued to present a social reality that is intended for and in need of interrogation: the Filipino bakla. The musical implicitly features the bakla as a cosmopolitan. At the outset, this cosmopolitan disposition comes from the fact that the characters are migrant workers (caregivers). But more importantly, the cosmopolitan character is from a responsibility toward the other anchored within a genuine caring as implicated in the affective labor of these caregiver characters. In the critique, the essay marks some problematic limitations in the treatment of the bakla. In doing so, the musical, despite its attempt to present a social reality, is a problem play, a social drama touching social issues--realistic in approach, but the representation seems like an editorial. In the final analysis, The Care Divas is argued to seemingly fail because artists are not able to see the complexity of their chosen subject in a bigger picture. PMID:26291029

  5. Investigation of factors affecting terrestrial passive sampling device performance and uptake rates in laboratory chambers

    SciTech Connect

    Johnson, K.A.; Weisskopf, C.P.

    1995-12-31

    A rapid sampling method using passive sampling devices (PSDS) for soil contaminant characterization shows extreme promise. The use of PSDs increases ease and speed of analysis, decreases solvent usage and cost, and minimizes the transport of contaminated soils. Time and cost savings allow a high sampling frequency, providing a more thorough site characterization than traditional methods. The authors have conducted both laboratory and field studies with terrestrial PSDS. Laboratory studies demonstrated the concentration and moisture dependence of sampler uptake and provided an estimate of the optimal field sampling time for soils contaminated with polychlorinated biphenyls (PCBs). These PSDs were also used to accurately estimate PCB concentrations at hazardous waste site where concentrations ranged from 0.01 to 200 ug PCB/g soil. However, PSDs in the field had sampling rates approximately three times greater than in the laboratory. As a result several factors affecting PSD sampling rates and/or performance in laboratory chambers were evaluated. The parameters investigated were soil bulk density or compactness, chamber size and air flow. The chemicals used in these studies included two PCB congeners (52 and 153), three organochlorine pesticides (DDT, dieldrin and methoxychlor), three organophosphate pesticides (chlorpyrifos, diazinon and terbufos) and three herbicides (alachlor, atrazine and metolachlor).

  6. Microvesicle formulations used in topical drugs and cosmetics affect product efficiency, performance and allergenicity.

    PubMed

    Madsen, Jakob Torp; Andersen, Klaus Ejner

    2010-01-01

    Attempts to improve the formulations of topical products are continuing processes (ie, to increase cosmetic performance, enhance effects, and protect ingredients from degradation). The development of micro- and nanovesicular systems has led to the marketing of topical drugs and cosmetics that use these technologies. Several articles have reported improved clinical efficacy by the encapsulation of pharmaceuticals in vesicular systems, and the numbers of publications and patents are rising. Some vesicular systems may deliver the drug deeper in the skin as compared to conventional vehicles, or even make transdermal delivery more efficient for a number of drugs. Vesicular systems may also allow a more precise drug delivery to the site of action (ie, the hair follicles) and thereby minimize the applied drug concentration, reducing potential side effects. On the other hand, this may increase the risk of other side effects. Few case reports have suggested that microvesicle formulations may affect the allergenicity of topical products. This article gives an overview of the current knowledge about the topical use of microvesicular systems and the dermatoallergologic aspects. PMID:20920408

  7. Cardiovascular and affective consequences of ruminating on a performance stressor depend on mode of thought.

    PubMed

    Zoccola, Peggy M; Rabideau, Erin M; Figueroa, Wilson S; Woody, Alex

    2014-08-01

    Psychological detachment from work is important for facilitating recovery. This can be threatened by rumination, or thinking about the day's stressors. Rumination may lead to distress, fatigue and extended activation of stress-related systems, but findings are not unequivocal. Level of construal (abstract or concrete) and type of mentation (imagery or verbal thought) used during stressor-focused rumination may shape physiological and affective responses and impact recovery. This study tested whether blood pressure (BP) and anxiety responses to stressor-focused rumination differ by mentation type and construal level. Healthy undergraduates (n = 136) performed a speech stressor and then completed a rumination task in one of four randomly assigned conditions: concrete imagery, abstract imagery, concrete verbal thought or abstract verbal thought. Anxiety and continuous BP were assessed. Concrete rumination led to greater BP, whereas rumination with abstract construals led to lower BP. Furthermore, participants in the abstract conditions had greater increases in anxiety following stressor-focused rumination than in the concrete conditions. Results suggest that the immediate physiological and psychological consequences of stressor-focused rumination depend upon mode of thought. PMID:25100270

  8. Rearing conditions differently affect the motor performance and cerebellar morphology of prenatally stressed juvenile rats.

    PubMed

    Ulupinar, Emel; Erol, Kevser; Ay, Hakan; Yucel, Ferruh

    2015-02-01

    The cerebellum is one of the most vulnerable parts of the brain to environmental changes. In this study, the effect of diverse environmental rearing conditions on the motor performances of prenatally stressed juvenile rats and its reflection to the cerebellar morphology were investigated. Prenatally stressed Wistar rats were grouped according to different rearing conditions (Enriched=EC, Standard=SC and Isolated=IC) after weaning. Six weeks later, male and female offspring from different litters were tested behaviorally. In rotarod and string suspension tests, females gained better scores than males. Significant gender and housing effects were observed especially on the motor functions requiring fine skills with the best performance by enriched females, but the worst by enriched males. The susceptibility of cerebellar macro- and micro-neurons to environmental conditions was compared using stereological methods. In female groups, no differences were observed in the volume proportions of cerebellar layers, soma sizes and the numerical densities of granule or Purkinje cells. However, a significant interaction between housing and gender was observed in the granule to Purkinje cell ratio of males, due to the increased numerical densities of the granule cells in enriched males. These data imply that proper functioning of the cerebellum relies on its well organized and evolutionarily conserved structure and circuitry. Although early life stress leads to long term behavioral and neurobiological consequences in the offspring, diverse rearing conditions can alter the motor skills of animals and synaptic connectivity between Purkinje and granular cells in a gender dependent manner. PMID:25315128

  9. Optimum Performance-Based Reliability Design of Structures

    NASA Astrophysics Data System (ADS)

    Papadrakakis, M.; Fragiadakis, M.; Lagaros, N. D.

    The objective of this paper is to present a performance based design procedure for steel structures in the framework of structural optimization. The structural performance is evaluated by means of the reliability demand and resistance methodology of FEMA-350 (Federal Emergency Management Agency) guidelines where the uncertainties and randomness in capacity and seismic demand are taken into account in a consistent manner. The structure has to be able to respond for different hazard levels with a desired confidence. Both Nonlinear Static and Nonlinear Dynamic analysis procedures are used in order to obtain the response for two hazard levels. The design procedure is performed in a structural optimization environment, where the Evolution Strategies algorithm is implemented for the solution of the optimization problem. In order to handle the excessive computational cost the inelastic time history analyses are performed in a parallel computing environment. The objective of the study is to obtain the design with the least material weight, and thus with less cost, that is capable to respond with the desired confidence for each performance level following the specifications of FEMA-350.

  10. Neonatal handling alters the structure of maternal behavior and affects mother-pup bonding.

    PubMed

    Reis, A R; de Azevedo, M S; de Souza, M A; Lutz, M L; Alves, M B; Izquierdo, I; Cammarota, M; Silveira, P P; Lucion, A B

    2014-05-15

    During early life, a mother and her pups establish a very close relationship, and the olfactory learning of the nest odor is very important for the bond formation. The olfactory bulb (OB) is a structure that plays a fundamental role in the olfactory learning (OL) mechanism that also involves maternal behavior (licking and contact). We hypothesized that handling the pups would alter the structure of the maternal behavior, affect OL, and alter mother-pup relationships. Moreover, changes in the cyclic AMP-response element binding protein phosphorylation (CREB) and neurotrophic factors could be a part of the mechanism of these changes. This study aimed to analyze the effects of neonatal handling, 1 min per day from postpartum day 1 to 10 (PPD 1 to PPD 10), on the maternal behavior and pups' preference for the nest odor in a Y maze (PPD 11). We also tested CREB's phosphorylation and BDNF signaling in the OB of the pups (PPD 7) by Western blot analysis. The results showed that handling alters mother-pups interaction by decreasing mother-pups contact and changing the temporal pattern of all components of the maternal behavior especially the daily licking and nest-building. We found sex-dependent changes in the nest odor preference, CREB and BDNF levels in pups OB. Male pups were more affected by alterations in the licking pattern, and female pups were more affected by changes in the mother-pup contact (the time spent outside the nest and nursing). PMID:24598277

  11. Elevated atmospheric CO2 levels affect community structure of rice root-associated bacteria

    PubMed Central

    Okubo, Takashi; Liu, Dongyan; Tsurumaru, Hirohito; Ikeda, Seishi; Asakawa, Susumu; Tokida, Takeshi; Tago, Kanako; Hayatsu, Masahito; Aoki, Naohiro; Ishimaru, Ken; Ujiie, Kazuhiro; Usui, Yasuhiro; Nakamura, Hirofumi; Sakai, Hidemitsu; Hayashi, Kentaro; Hasegawa, Toshihiro; Minamisawa, Kiwamu

    2015-01-01

    A number of studies have shown that elevated atmospheric CO2 ([CO2]) affects rice yields and grain quality. However, the responses of root-associated bacteria to [CO2] elevation have not been characterized in a large-scale field study. We conducted a free-air CO2 enrichment (FACE) experiment (ambient + 200 μmol.mol−1) using three rice cultivars (Akita 63, Takanari, and Koshihikari) and two experimental lines of Koshihikari [chromosome segment substitution and near-isogenic lines (NILs)] to determine the effects of [CO2] elevation on the community structure of rice root-associated bacteria. Microbial DNA was extracted from rice roots at the panicle formation stage and analyzed by pyrosequencing the bacterial 16S rRNA gene to characterize the members of the bacterial community. Principal coordinate analysis of a weighted UniFrac distance matrix revealed that the community structure was clearly affected by elevated [CO2]. The predominant community members at class level were Alpha-, Beta-, and Gamma-proteobacteria in the control (ambient) and FACE plots. The relative abundance of Methylocystaceae, the major methane-oxidizing bacteria in rice roots, tended to decrease with increasing [CO2] levels. Quantitative PCR revealed a decreased copy number of the methane monooxygenase (pmoA) gene and increased methyl coenzyme M reductase (mcrA) in elevated [CO2]. These results suggest elevated [CO2] suppresses methane oxidation and promotes methanogenesis in rice roots; this process affects the carbon cycle in rice paddy fields. PMID:25750640

  12. TMD-Based Structural Control of High Performance Steel Bridges

    NASA Astrophysics Data System (ADS)

    Kim, Tae Min; Kim, Gun; Kyum Kim, Moon

    2012-08-01

    The purpose of this study is to investigate the effectiveness of structural control using tuned mass damper (TMD) for suppressing excessive traffic induced vibration of high performance steel bridge. The study considered 1-span steel plate girder bridge and bridge-vehicle interaction using HS-24 truck model. A numerical model of steel plate girder, traffic load, and TMD is constructed and time history analysis is performed using commercial structural analysis program ABAQUS 6.10. Results from analyses show that high performance steel bridge has dynamic serviceability problem, compared to relatively low performance steel bridge. Therefore, the structural control using TMD is implemented in order to alleviate dynamic serviceability problems. TMD is applied to the bridge with high performance steel and then vertical vibration due to dynamic behavior is assessed again. In consequent, by using TMD, it is confirmed that the residual amplitude is appreciably reduced by 85% in steady-state vibration. Moreover, vibration serviceability assessment using 'Reiher-Meister Curve' is also remarkably improved. As a result, this paper provides the guideline for economical design of I-girder using high performance steel and evaluates the effectiveness of structural control using TMD, simultaneously.

  13. Affect and Managerial Performance: A Test of the Sadder-but-Wiser vs. Happier-and-Smarter Hypotheses.

    ERIC Educational Resources Information Center

    Staw, Barry M.; Barsade, Sigal G.

    1993-01-01

    Provides a comparative test of two psychological theories concerning the relationship between affect and performance. Used managerial simulations to test whether people with positive dispositions perform better or worse on both decisional and interpersonal tasks. Results support the happier-and-smarter, as opposed to the sadder-but-wiser,…

  14. The use of noncrystallographic symmetry averaging to solve structures from data affected by perfect hemihedral twinning

    PubMed Central

    Sabin, Charles; Plevka, Pavel

    2016-01-01

    Hemihedral twinning is a crystal-growth anomaly in which a specimen is composed of two crystal domains that coincide with each other in three dimensions. However, the orientations of the crystal lattices in the two domains differ in a specific way. In diffraction data collected from hemihedrally twinned crystals, each observed intensity contains contributions from both of the domains. With perfect hemihedral twinning, the two domains have the same volumes and the observed intensities do not contain sufficient information to detwin the data. Here, the use of molecular replacement and of noncrystallographic symmetry (NCS) averaging to detwin a 2.1 Å resolution data set for Aichi virus 1 affected by perfect hemihedral twinning is described. The NCS averaging enabled the correction of errors in the detwinning introduced by the differences between the molecular-replacement model and the crystallized structure. The procedure permitted the structure to be determined from a molecular-replacement model that had 16% sequence identity and a 1.6 Å r.m.s.d. for Cα atoms in comparison to the crystallized structure. The same approach could be used to solve other data sets affected by perfect hemihedral twinning from crystals with NCS. PMID:26919522

  15. Relationships between middle school students' science concept structure interrelatedness competence and selected cognitive and affective tendencies

    NASA Astrophysics Data System (ADS)

    Harty, Harold; Hamrick, Linda; Samuel, K. V.

    An investigation was conducted to determine the relationships between Concept Structure Interrelatedness Competence (ConSIC) and 10 predictor variables of which 6 comprised a cognitive cluster and 4 made up an affective set. Data were collected from 105 middle school students and treated by way of stepwise multiple regression, linear multiple regression, and product-moment correlation techniques. The findings revealed that previous experience with concept structure interrelatedness and verbal scholastic aptitude accounted for the greatest amount of variance in predicting ConSIC. Significant positive correlations were also found between ConSIC and science achievement-course grades, scholastic aptitude-verbal, scholastic aptitude-quantitative, previous experience with concept structure interrelatedness, and self-concept of science ability. Positive significant correlations also surfaced among all of the affective variables (attitudes toward science, interest in science, science curiosity, and self-concept of science ability). Implications have been discussed in terms of classroom science teaching, science content analysis, curriculum design, and content selection.

  16. DISC1 gene and affective psychopathology: a combined structural and functional MRI study.

    PubMed

    Opmeer, Esther M; van Tol, Marie-José; Kortekaas, Rudie; van der Wee, Nic J A; Woudstra, Saskia; van Buchem, Mark A; Penninx, Brenda W; Veltman, Dick J; Aleman, André

    2015-02-01

    The gene Disrupted-In-Schizophrenia-1 (DISC1) has been indicated as a determinant of psychopathology, including affective disorders, and shown to influence prefrontal cortex (PFC) and hippocampus functioning, regions of major interest for affective disorders. We aimed to investigate whether DISC1 differentially modulates brain function during executive and memory processing, and morphology in regions relevant for depression and anxiety disorders (affective disorders). 128 participants, with (n = 103) and without (controls; n = 25) affective disorders underwent genotyping for Ser704Cys (with Cys-allele considered as risk-allele) and structural and functional (f) Magnetic Resonance Imaging (MRI) during visuospatial planning and emotional episodic memory tasks. For both voxel-based morphometry and fMRI analyses, we investigated the effect of genotype in controls and explored genotypeXdiagnosis interactions. Results are reported at p < 0.05 FWE small volume corrected. In controls, Cys-carriers showed smaller bilateral (para)hippocampal volumes compared with Ser-homozygotes, and lower activation in the anterior cingulate cortex (ACC) and dorsolateral PFC during visuospatial planning. In anxiety patients, Cys-carriers showed larger (para)hippocampal volumes and more ACC activation during visuospatial planning. In depressive patients, no effect of genotype was observed and overall, no effect of genotype on episodic memory processing was detected. We demonstrated that Ser704Cys-genotype influences (para)hippocampal structure and functioning the dorsal PFC during executive planning, most prominently in unaffected controls. Results suggest that presence of psychopathology moderates Ser704Cys effects. PMID:25533973

  17. Double jeopardy! The additive consequences of negative affect on performance-monitoring decrements following traumatic brain injury.

    PubMed

    Larson, Michael J; Kaufman, David A S; Kellison, Ida L; Schmalfuss, Ilona M; Perlstein, William M

    2009-07-01

    Survivors of severe traumatic brain injury (TBI) are at increased risk for emotional sequelae. The current study utilized the error-related negativity (ERN) and posterror positivity (Pe) components of the event-related potential (ERP) to test the hypothesis that negative affect disproportionately impairs performance-monitoring following severe TBI. High-density ERPs were acquired while 20 survivors of severe TBI and 20 demographically matched controls performed a single-trial Stroop task. Response-locked ERPs were separately averaged for correct and error trials. Negative affect was measured as the single latent factor of measures of depression and anxiety. Groups did not differ on overall level of negative affect. Control and TBI participants did not differ on error rates as a function of negative affect, but differed in response times. ERP results revealed disproportionately smaller ERN amplitudes in participants with TBI relative to controls as a function of negative affect. Pe amplitude did not differ between groups. Negative affect inversely correlated with ERN amplitude in TBI but not control participants. Overall, results support a "double jeopardy" hypothesis of disproportionate impairments in performance monitoring when negative affect is overlaid on severe TBI. PMID:19586208

  18. High-performance insulator structures for accelerator applications

    SciTech Connect

    Sampayan, S.E.; Caporaso, G.J.; Sanders, D.M.; Stoddard, R.D.; Trimble, D.O.; Elizondo, J.; Krogh, M.L.; Wieskamp, T.F.

    1997-05-01

    A new, high gradient insulator technology has been developed for accelerator systems. The concept involves the use of alternating layers of conductors and insulators with periods of order 1 mm or less. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We describe our ongoing studies investigating the degradation of the breakdown electric field resulting from alternate fabrication techniques, the effect of gas pressure, the effect of the insulator-to-electrode interface gap spacing, and the performance of the insulator structure under bi-polar stress.

  19. Feeding Experience of Bemisia tabaci (Hemiptera: Aleyrodidae) Affects Their Performance on Different Host Plants

    PubMed Central

    Shah, M. Mostafizur Rahman; Liu, Tong-Xian

    2013-01-01

    The sweetpotato whitefly, Bemisia tabaci biotype B is extremely polyphagous with >600 species of host plants. We hypothesized that previous experience of the whitefly on a given host plant affects their host selection and performance on the plants without previous experience. We investigated the host selection for feeding and oviposition of adults and development and survival of immatures of three host-plant-experienced populations of B. tabaci, namely Bemisia-eggplant, Bemisia-tomato and Bemisia-cucumber, on their experienced host plant and each of the three other plant species (eggplant, tomato, cucumber and pepper) without previous experience. We found that the influence of previous experience of the whiteflies varied among the populations. All populations refused pepper for feeding and oviposition, whereas the Bemisia-cucumber and the Bemisia-eggplant strongly preferred cucumber. Bemisia-tomato did not show strong preference to any of the three host palnts. Development time from egg to adult eclosion varied among the populations, being shortest on eggplant, longest on pepper, and intermediate on tomato and cucumber except for the Bemisia-cucumber developed similarly on tomato and pepper. The survivorship from egg to adult eclosion of all populations was highest on eggplant (80-98%), lowest on pepper (0-20%), and intermediate on tomato and cucumber. In conclusion, the effects of previous experience of whiteflies on host selection for feeding and oviposition, development, and survivorship varied depending on host plants, and host plants play a stronger role than previous experience. Preference of feeding and oviposition by adults may not accurately reflect host suitability of immatures. These results provided important information for understanding whitefly population dynamics and dispersal among different crop systems. PMID:24146985

  20. Exposure to Cerium Dioxide Nanoparticles Differently Affect Swimming Performance and Survival in Two Daphnid Species

    PubMed Central

    Artells, Ester; Issartel, Julien; Auffan, Mélanie; Borschneck, Daniel; Thill, Antoine; Tella, Marie; Brousset, Lenka; Rose, Jérôme; Bottero, Jean-Yves; Thiéry, Alain

    2013-01-01

    The CeO2 NPs are increasingly used in industry but the environmental release of these NPs and their subsequent behavior and biological effects are currently unclear. This study evaluates for the first time the effects of CeO2 NPs on the survival and the swimming performance of two cladoceran species, Daphnia similis and Daphnia pulex after 1, 10 and 100 mg.L−1 CeO2 exposures for 48 h. Acute toxicity bioassays were performed to determine EC50 of exposed daphnids. Video-recorded swimming behavior of both daphnids was used to measure swimming speeds after various exposures to aggregated CeO2 NPs. The acute ecotoxicity showed that D. similis is 350 times more sensitive to CeO2 NPs than D. pulex, showing 48-h EC50 of 0.26 mg.L−1 and 91.79 mg.L−1, respectively. Both species interacted with CeO2 NPs (adsorption), but much more strongly in the case of D. similis. Swimming velocities (SV) were differently and significantly affected by CeO2 NPs for both species. A 48-h exposure to 1 mg.L−1 induced a decrease of 30% and 40% of the SV in D. pulex and D. similis, respectively. However at higher concentrations, the SV of D. similis was more impacted (60% off for 10 mg.L−1 and 100 mg.L−1) than the one of D. pulex. These interspecific toxic effects of CeO2 NPs are explained by morphological variations such as the presence of reliefs on the cuticle and a longer distal spine in D. similis acting as traps for the CeO2 aggregates. In addition, D. similis has a mean SV double that of D. pulex and thus initially collides with twice more NPs aggregates. The ecotoxicological consequences on the behavior and physiology of a CeO2 NPs exposure in daphnids are discussed. PMID:23977004

  1. Clonal structure affects the assembling behavior in the Japanese queenless ant Pristomyrmex punctatus

    NASA Astrophysics Data System (ADS)

    Nishide, Yudai; Satoh, Toshiyuki; Hiraoka, Tuyosi; Obara, Yoshiaki; Iwabuchi, Kikuo

    2007-10-01

    The queenless ant Pristomyrmex punctatus (Hymenoptera: Myrmicinae) has a unique society that differs from those of other typical ants. This species does not have a queen, and the workers lay eggs and produce their clones parthenogenetically. However, a colony of these ants does not always comprise members derived from a single clonal line. In this study, we examined whether P. punctatus changes its “assembling behavior” based on colony genetic structure. We prepared two subcolonies—a larger one comprising 200 individuals and a smaller one comprising 100 individuals; these subcolonies were established from a single stock colony. We investigated whether these subcolonies assemble into a single nest. The genetically monomorphic subcolonies (single clonal line) always fused into a single nest; however, the genetically polymorphic subcolonies (multiple clonal lines) did not tend to form a single colony. The present study is the first to demonstrate that the colony genetic structure significantly affects social viscosity in social insects.

  2. Prediction of structural materials performance at long-term service in space conditions

    NASA Astrophysics Data System (ADS)

    Bakushin, S. V.; Demidov, D. L.; Morozov, Iu. D.; Nikitskii, V. P.; Churilo, I. V.

    An evaluation is made of the factors affecting the performance of materials with weld-jointed structures in the orbital environment. Internal factors familiar from terrestrial applications encompass impurities and material inhomogeneities, property anisotropies, and dislocation densities; external factors unique to the space environment are one-sided cyclic heating, Em radiation, upper-atmosphere corrosion, and particle impacts. These factors can result in mechanical stresses, chemical and electrochemical corrosion, microcracking, outgassing, and phase transitions.

  3. Computational Performance Evaluation of a Side Structure Considering Stamping Effects

    NASA Astrophysics Data System (ADS)

    Kim, Se-Ho; Kim, Kee-Poong

    In this paper, the influence of the stamping effect is investigated in the performance analysis of a side structure. The analysis covers the performance evaluation such as crashworthiness and NVH. Stamping analyses are carried out for a center pillar, and then, numerical simulations are carried out in order to identify the stamping effect on the crashworthiness and the natural frequency. The result shows that the analysis considering the forming history leads to a different result from that without considering the stamping effect, which demonstrates that the design of auto-body should be carried out considering the stamping history for accurate assessment of various performances.

  4. Colorimetric Method for Identifying Plant Essential Oil Components That Affect Biofilm Formation and Structure

    PubMed Central

    Niu, C.; Gilbert, E. S.

    2004-01-01

    The specific biofilm formation (SBF) assay, a technique based on crystal violet staining, was developed to locate plant essential oils and their components that affect biofilm formation. SBF analysis determined that cinnamon, cassia, and citronella oils differentially affected growth-normalized biofilm formation by Escherichia coli. Examination of the corresponding essential oil principal components by the SBF assay revealed that cinnamaldehyde decreased biofilm formation compared to biofilms grown in Luria-Bertani broth, eugenol did not result in a change, and citronellol increased the SBF. To evaluate these results, two microscopy-based assays were employed. First, confocal laser scanning microscopy (CLSM) was used to examine E. coli biofilms cultivated in flow cells, which were quantitatively analyzed by COMSTAT, an image analysis program. The overall trend for five parameters that characterize biofilm development corroborated the findings of the SBF assay. Second, the results of an assay measuring growth-normalized adhesion by direct microscopy concurred with the results of the SBF assay and CLSM imaging. Viability staining indicated that there was reduced toxicity of the essential oil components to cells in biofilms compared to the toxicity to planktonic cells but revealed morphological damage to E. coli after cinnamaldehyde exposure. Cinnamaldehyde also inhibited the swimming motility of E. coli. SBF analysis of three Pseudomonas species exposed to cinnamaldehyde, eugenol, or citronellol revealed diverse responses. The SBF assay could be useful as an initial step for finding plant essential oils and their components that affect biofilm formation and structure. PMID:15574886

  5. The performance of the Hydromorphological Index of Diversity (HMID) in a hydropower affected meandering river

    NASA Astrophysics Data System (ADS)

    Stähly, Severin; Bourqui, Pierre; Franca, Mario J.; Robinson, Christopher; Schleiss, Anton J.

    2016-04-01

    More than half of the Swiss electricity is produced by hydropower. Large price fluctuations cause severe hydropeaking flow regimes due to corresponding production fluctuations, which undisputedly have a negative impact on aquatic biota. Water diversion due to dams on the other hand imposes downstream residual flow regimes. The absence of flood events and regular sediment supply disrupts sediment dynamics and disconnects floodplains, which are habitats of high value, from its main channel. The residual-flow controlled reach at the Sarine river in western Switzerland is the subject of the present study. The Sarine meanders strongly and the river reach under analysis has a bed incision of locally more than 100 m. Its incision provokes the isolation of the river which is consequently minimally touched by human structures and shows a natural geomorphology. Since the construction of a dam upstream this reach in 1948, aiming at the water abstraction to hydropower, vegetation could establish and the active floodplain decreased its area, as airborne images show. Nevertheless, it is classified as a floodplain of national importance and it has been under protection since 1992. It is supposed to be a valuable habitat for a wide range of organisms. The Hydromorphological Index of Diversity (HMID) is a simple tool for quantifying the habitat richness in a river reach, taking into account the mean values and the variation of water depth and flow velocity. For channelized rivers, HMID values from up to 5 are expected, while morphological pristine sites with a high spatial variability of water depth and velocity show values of 9 or higher. For the residual flow of the Sarine River, flow depth and velocity were measured using ADCP and ADV. The results are compared with a nearby natural reference river and the outcome of a 2D numerical simulation. Finally, the behaviour and limitations of the HMID, in a hydropower affected river, are discussed. In the close future an artificial flood

  6. The Local Job Bank Program: Performance, Structure, and Direction.

    ERIC Educational Resources Information Center

    Ullman, Joseph C.; Huber, George P.

    The book represents an effort to assess the performance, structure, and direction of the Job Bank Program of the Public Employment Service, a program meant to improve the functioning of the labor market information system in the United States. The research had three goals: to assess the relative goal achievement of job banks; to determine its…

  7. Internal Structure of DISCOVER: A Performance-based Assessment.

    ERIC Educational Resources Information Center

    Sarouphim, Ketty M.

    2000-01-01

    A study involving 257 Navajo and Mexican-American elementary students investigated the internal structure of the DISCOVER assessment, a performance-based assessment grounded in Gardner's theory of multiple intelligence. Results showed low interrating correlations among the five assessment activities, indicating students gifted in one intelligence…

  8. Examining Culture and Performance at Different Middle School Level Structures

    ERIC Educational Resources Information Center

    Gomez, Martin Omar; Marcoulides, George A.; Heck, Ronald H.

    2012-01-01

    Purpose: The purpose of this study is to propose and test a model of school culture and examine data from schools in Southern California to identify educationally important aspects of teacher-perceived cultural variables and how these perceptions differentially impact school performance in K-8 and middle school structures.…

  9. Process for predicting structural performance of mechanical systems

    DOEpatents

    Gardner, David R.; Hendrickson, Bruce A.; Plimpton, Steven J.; Attaway, Stephen W.; Heinstein, Martin W.; Vaughan, Courtenay T.

    1998-01-01

    A process for predicting the structural performance of a mechanical system represents the mechanical system by a plurality of surface elements. The surface elements are grouped according to their location in the volume occupied by the mechanical system so that contacts between surface elements can be efficiently located. The process is well suited for efficient practice on multiprocessor computers.

  10. The Effect of Structured Worksheets on Student Performance.

    ERIC Educational Resources Information Center

    Green, Thomas G.; And Others

    1986-01-01

    A study of student test performance in a preclinical operative dentistry amalgam course revealed that structured worksheets linked to videotape and lecture presentations improved immediate recall of key points for both presentation types and were well-received by students. Other worksheet uses are suggested. (MSE)

  11. Process for predicting structural performance of mechanical systems

    DOEpatents

    Gardner, D.R.; Hendrickson, B.A.; Plimpton, S.J.; Attaway, S.W.; Heinstein, M.W.; Vaughan, C.T.

    1998-05-19

    A process for predicting the structural performance of a mechanical system represents the mechanical system by a plurality of surface elements. The surface elements are grouped according to their location in the volume occupied by the mechanical system so that contacts between surface elements can be efficiently located. The process is well suited for efficient practice on multiprocessor computers. 12 figs.

  12. An Analysis of Factors Affecting Teacher Attrition in High Performing and Low Performing Elementary Rural Schools in South Carolina

    ERIC Educational Resources Information Center

    Carter-Blocker, Vickie R.

    2012-01-01

    The purpose of this study was to examine the factors impacting teacher attrition in high-performing and low-performing elementary rural schools in South Carolina. Several factors were identified that interfered with teachers returning to the teaching profession. School districts in rural areas need to be better informed of the factors that affect…

  13. An investigation of factors affecting the entry of radon into structures on the Island of Guam

    SciTech Connect

    Kladder, D.L.; Burkhart, J.F.; Thorburn, M.S.

    1995-12-31

    Factors affecting the entry of radon-222 gas into structures on the Island of Guam were investigated during the summer of 1993. Research findings indicated that radon transport into buildings on Guam, and perhaps in other tropical areas, is driven by sub-grade soil pressure (positive with respect to atmospheric pressure) rather than interior buildings vacuums. Immediate and substantive increases in indoor radon concentrations were associated with environmental effects of wind and rain. Radon entry, and hence indoor radon concentrations, is significantly greater during the rainy season as opposed to the dry season. In the absence of mechanically induced interior vacuums in buildings, external environmental forces creating sub-slab pressures are the predominant factor in affecting radon entry in Guam. Indoor radon potentials can be correlated to the locations where the underlying geology is limestone. Furthermore, the radon source appears to be within the first few feet of the surface of these limestones rather than uniformly distributed throughout the limestone. The effects of seismic activity on radon entry are short-lived unless significant damage occurs to a structure. Radon entry during calm weather conditions may also be a function of the rising and falling of ocean tides.

  14. Diversity and structure of AMF communities as affected by tillage in a temperate soil.

    PubMed

    Jansa, J; Mozafar, A; Anken, T; Ruh, R; Sanders, I R; Frossard, E

    2002-10-01

    Arbuscular mycorrhizal fungi (AMF) were studied in differently tilled soils from a long-term field experiment in Switzerland. Diversity and structure of AMF communities were surveyed either directly on spores isolated from the field soil or on spores isolated from trap cultures, planted with different host plants. Single-spore cultures were established from the AMF spores obtained from trap cultures. Identification of the AMF was made by observation of spore morphology and confirmed by sequencing of ITS rDNA. At least 17 recognised AMF species were identified in samples from field and/or trap cultures, belonging to five genera of AMF--Glomus, Gigaspora, Scutellospora, Acaulospora, and Entrophospora. Tillage had a significant influence on the sporulation of some species and non- Glomus AMF tended to be more abundant in the no-tilled soil. The community structure of AMF in the field soil was significantly affected by tillage treatment. However, no significant differences in AMF diversity were detected among different soil tillage treatments. AMF community composition in trap cultures was affected much more by the species of the trap plant than by the original tillage treatment of the field soil. The use of trap cultures for fungal diversity estimation in comparison with direct observation of field samples is discussed. PMID:12375133

  15. The structure and duplex context of DNA interstrand crosslinks affects the activity of DNA polymerase η

    PubMed Central

    Roy, Upasana; Mukherjee, Shivam; Sharma, Anjali; Frank, Ekaterina G.; Schärer, Orlando D.

    2016-01-01

    Several important anti-tumor agents form DNA interstrand crosslinks (ICLs), but their clinical efficiency is counteracted by multiple complex DNA repair pathways. All of these pathways require unhooking of the ICL from one strand of a DNA duplex by nucleases, followed by bypass of the unhooked ICL by translesion synthesis (TLS) polymerases. The structures of the unhooked ICLs remain unknown, yet the position of incisions and processing of the unhooked ICLs significantly influence the efficiency and fidelity of bypass by TLS polymerases. We have synthesized a panel of model unhooked nitrogen mustard ICLs to systematically investigate how the state of an unhooked ICL affects pol η activity. We find that duplex distortion induced by a crosslink plays a crucial role in translesion synthesis, and length of the duplex surrounding an unhooked ICL critically affects polymerase efficiency. We report the synthesis of a putative ICL repair intermediate that mimics the complete processing of an unhooked ICL to a single crosslinked nucleotide, and find that it provides only a minimal obstacle for DNA polymerases. Our results raise the possibility that, depending on the structure and extent of processing of an ICL, its bypass may not absolutely require TLS polymerases. PMID:27257072

  16. Structural brain network analysis in families multiply affected with bipolar I disorder.

    PubMed

    Forde, Natalie J; O'Donoghue, Stefani; Scanlon, Cathy; Emsell, Louise; Chaddock, Chris; Leemans, Alexander; Jeurissen, Ben; Barker, Gareth J; Cannon, Dara M; Murray, Robin M; McDonald, Colm

    2015-10-30

    Disrupted structural connectivity is associated with psychiatric illnesses including bipolar disorder (BP). Here we use structural brain network analysis to investigate connectivity abnormalities in multiply affected BP type I families, to assess the utility of dysconnectivity as a biomarker and its endophenotypic potential. Magnetic resonance diffusion images for 19 BP type I patients in remission, 21 of their first degree unaffected relatives, and 18 unrelated healthy controls underwent tractography. With the automated anatomical labelling atlas being used to define nodes, a connectivity matrix was generated for each subject. Network metrics were extracted with the Brain Connectivity Toolbox and then analysed for group differences, accounting for potential confounding effects of age, gender and familial association. Whole brain analysis revealed no differences between groups. Analysis of specific mainly frontal regions, previously implicated as potentially endophenotypic by functional magnetic resonance imaging analysis of the same cohort, revealed a significant effect of group in the right medial superior frontal gyrus and left middle frontal gyrus driven by reduced organisation in patients compared with controls. The organisation of whole brain networks of those affected with BP I does not differ from their unaffected relatives or healthy controls. In discreet frontal regions, however, anatomical connectivity is disrupted in patients but not in their unaffected relatives. PMID:26382105

  17. Is long-term structural priming affected by patterns of experience with individual verbs?

    PubMed Central

    Kaschak, Michael P.; Borreggine, Kristin L.

    2015-01-01

    Several recent papers have reported long-term structural priming effects in experiments where previous patterns of experience with the double object and prepositional object constructions are shown to affect later patterns of language production for those constructions. The experiments reported in this paper address the extent to which these long-term priming effects are modulated by the participants’ patterns of experience with particular verbs within the double object and prepositional object constructions. The results of three experiments show that patterns of experience with particular verbs using the double object or prepositional object constructions do not have much effect on the shape of the longterm structural priming effects reported elsewhere in the literature. These findings lend support to the claim that structural priming is the result of adaptations to the language production system that occur on an abstract, structural level of representation that is separate from representations regarding the behavior of particular lexical items in particular constructions [e.g., Chang, F., Dell, G. S., & Bock, K. (2006). Becoming syntactic. Psychological Review, 113, 234–272]. 2007 Elsevier Inc. All rights reserved. PMID:26500391

  18. Process conditions affect starch structure and its interactions with proteins in rice pasta.

    PubMed

    Barbiroli, Alberto; Bonomi, Francesco; Casiraghi, Maria Cristina; Iametti, Stefania; Pagani, Maria Ambrogina; Marti, Alessandra

    2013-02-15

    Structural changes of starch and proteins in rice pasta were investigated as a function of raw-materials and pasta-making conditions, and their impact on cooking behaviour and glycaemic index was assessed. Rice pasta was prepared from untreated or parboiled rice flour by conventional extrusion or by extrusion-cooking. Starch structure was studied by assessing starch accessibility to specific enzymes (α-amylase and pullulanase), and by evaluating the molecular properties of fragments from enzymatic action. Protein solubility in presence/absence of chaotropes and accessibility of protein cysteine thiols allowed to evaluate the intensity and nature of inter-protein interactions. Parboiling stiffens the protein network in rice flour and makes starch more accessible to hydrolysis. Pasta-making induced further changes in the starch structure, that were most evident in pasta made from untreated rice and were mainly related to the amylopectin fraction. Thus, the interplay among structural modifications on starch and/or proteins affects the features of products. PMID:23399230

  19. Structural changes in emulsion-bound bovine beta-lactoglobulin affect its proteolysis and immunoreactivity.

    PubMed

    Marengo, Mauro; Miriani, Matteo; Ferranti, Pasquale; Bonomi, Francesco; Iametti, Stefania; Barbiroli, Alberto

    2016-07-01

    Adsorption on the surface of sub-micrometric oil droplets resulted in significant changes in the tertiary structure of bovine beta-lactoglobulin (BLG), a whey protein broadly used as a food ingredient and a major food allergen. The adsorbed protein had increased sensitivity to trypsin, and increased immunoreactivity towards specific monoclonal antibodies. In spite of the extensive tryptic breakdown of emulsion-bound BLG, some sequence stretches in BLG became trypsin-insensitive upon absorption of the protein on the fat droplets. As a consequence - at contrast with free BLG - proteolysis of emulsion-bound BLG did not decrease the immunoreactivity of the protein, and some of the large peptides generated by trypsinolysis of emulsion-bound BLG were still recognizable by specific monoclonal antibodies. Structural changes occurring in emulsion-bound BLG and their consequences are discussed in comparison with those occurring when the tertiary structure of BLG is modified by lipophilic salts, by urea, or upon interaction with solid hydrophobic surfaces. Such a comparison highlights the relevance of situation-specific structural modifications, that in turn may affect physiologically relevant features of the protein. PMID:27085639

  20. Host species and developmental stage, but not host social structure, affects bacterial community structure in socially polymorphic bees.

    PubMed

    McFrederick, Quinn S; Wcislo, William T; Hout, Michael C; Mueller, Ulrich G

    2014-05-01

    Social transmission and host developmental stage are thought to profoundly affect the structure of bacterial communities associated with honey bees and bumble bees, but these ideas have not been explored in other bee species. The halictid bees Megalopta centralis and M. genalis exhibit intrapopulation social polymorphism, which we exploit to test whether bacterial communities differ by host social structure, developmental stage, or host species. We collected social and solitary Megalopta nests and sampled bees and nest contents from all stages of host development. To survey these bacterial communities, we used 16S rRNA gene 454 pyrosequencing. We found no effect of social structure, but found differences by host species and developmental stage. Wolbachia prevalence differed between the two host species. Bacterial communities associated with different developmental stages appeared to be driven by environmentally acquired bacteria. A Lactobacillus kunkeei clade bacterium that is consistently associated with other bee species was dominant in pollen provisions and larval samples, but less abundant in mature larvae and pupae. Foraging adults appeared to often reacquire L. kunkeei clade bacteria, likely while foraging at flowers. Environmental transmission appears to be more important than social transmission for Megalopta bees at the cusp between social and solitary behavior. PMID:24579829

  1. Manipulation of logical structure of chemistry problems and its effect on student performance

    NASA Astrophysics Data System (ADS)

    Niaz, Mansoor; Robinson, William R.

    It has been shown previously that manipulation of the M demand (amount of information needed for processing) of chemistry problems affects student performance, which suggests that manipulation of logical structure of chemistry problems could also lead to significant changes in performance. The objective of this study is to investigate the following: Given the opportunity for training, what is the effect of increasing (manipulation) the complexity of logical structure of chemistry problems on student performance, and to what extent can cognitive variables explain changes in performance. Results obtained show that (a) even a small increase in the logical structure of a problem can change the role of cognitive variables (mental capacity and formal reasoning) to the extent that increase in logical complexity outweighs the advantage students may have gained through training on a similar problem; (b) the use of algorithms and training on particular types of chemistry problems could lead to a situation in which formal reasoning is the only cognitive variable that explains variance in performance significantly; and (c) after having solved very similar problems on two different occasions with improving performance, the improvement is not retained if the logical structure of a third problem increases considerably. It is concluded that when dealing with significant changes in logical complexity of chemistry problems, developmental level of students is the most consistent predictor of success. A model for the qualitative analysis of logical complexity of chemistry problems is presented.

  2. An affected core drives network integration deficits of the structural connectome in 22q11.2 deletion syndrome.

    PubMed

    Váša, František; Griffa, Alessandra; Scariati, Elisa; Schaer, Marie; Urben, Sébastien; Eliez, Stephan; Hagmann, Patric

    2016-01-01

    Chromosome 22q11.2 deletion syndrome (22q11DS) is a genetic disease known to lead to cerebral structural alterations, which we study using the framework of the macroscopic white-matter connectome. We create weighted connectomes of 44 patients with 22q11DS and 44 healthy controls using diffusion tensor magnetic resonance imaging, and perform a weighted graph theoretical analysis. After confirming global network integration deficits in 22q11DS (previously identified using binary connectomes), we identify the spatial distribution of regions responsible for global deficits. Next, we further characterize the dysconnectivity of the deficient regions in terms of sub-network properties, and investigate their relevance with respect to clinical profiles. We define the subset of regions with decreased nodal integration (evaluated using the closeness centrality measure) as the affected core (A-core) of the 22q11DS structural connectome. A-core regions are broadly bilaterally symmetric and consist of numerous network hubs - chiefly parietal and frontal cortical, as well as subcortical regions. Using a simulated lesion approach, we demonstrate that these core regions and their connections are particularly important to efficient network communication. Moreover, these regions are generally densely connected, but less so in 22q11DS. These specific disturbances are associated to a rerouting of shortest network paths that circumvent the A-core in 22q11DS, "de-centralizing" the network. Finally, the efficiency and mean connectivity strength of an orbito-frontal/cingulate circuit, included in the affected regions, correlate negatively with the extent of negative symptoms in 22q11DS patients, revealing the clinical relevance of present findings. The identified A-core overlaps numerous regions previously identified as affected in 22q11DS as well as in schizophrenia, which approximately 30-40% of 22q11DS patients develop. PMID:26870660

  3. An affected core drives network integration deficits of the structural connectome in 22q11.2 deletion syndrome

    PubMed Central

    Váša, František; Griffa, Alessandra; Scariati, Elisa; Schaer, Marie; Urben, Sébastien; Eliez, Stephan; Hagmann, Patric

    2015-01-01

    Chromosome 22q11.2 deletion syndrome (22q11DS) is a genetic disease known to lead to cerebral structural alterations, which we study using the framework of the macroscopic white-matter connectome. We create weighted connectomes of 44 patients with 22q11DS and 44 healthy controls using diffusion tensor magnetic resonance imaging, and perform a weighted graph theoretical analysis. After confirming global network integration deficits in 22q11DS (previously identified using binary connectomes), we identify the spatial distribution of regions responsible for global deficits. Next, we further characterize the dysconnectivity of the deficient regions in terms of sub-network properties, and investigate their relevance with respect to clinical profiles. We define the subset of regions with decreased nodal integration (evaluated using the closeness centrality measure) as the affected core (A-core) of the 22q11DS structural connectome. A-core regions are broadly bilaterally symmetric and consist of numerous network hubs — chiefly parietal and frontal cortical, as well as subcortical regions. Using a simulated lesion approach, we demonstrate that these core regions and their connections are particularly important to efficient network communication. Moreover, these regions are generally densely connected, but less so in 22q11DS. These specific disturbances are associated to a rerouting of shortest network paths that circumvent the A-core in 22q11DS, “de-centralizing” the network. Finally, the efficiency and mean connectivity strength of an orbito-frontal/cingulate circuit, included in the affected regions, correlate negatively with the extent of negative symptoms in 22q11DS patients, revealing the clinical relevance of present findings. The identified A-core overlaps numerous regions previously identified as affected in 22q11DS as well as in schizophrenia, which approximately 30–40% of 22q11DS patients develop. PMID:26870660

  4. Ecosystem structure, function, and composition in rangelands are negatively affected by livestock grazing.

    PubMed

    Eldridge, David J; Poore, Alistair G B; Ruiz-Colmenero, Marta; Letnic, Mike; Soliveres, Santiago

    2016-06-01

    Reports of positive or neutral effects of grazing on plant species richness have prompted calls for livestock grazing to be used as a tool for managing land for conservation. Grazing effects, however, are likely to vary among different response variables, types, and intensity of grazing, and across abiotic conditions. We aimed to examine how grazing affects ecosystem structure, function, and composition. We compiled a database of 7615 records reporting an effect of grazing by sheep and cattle on 278 biotic and abiotic response variables for published studies across Australia. Using these data, we derived three ecosystem measures based on structure, function, and composition, which were compared against six contrasts of grazing pressure, ranging from low to heavy, two different herbivores (sheep, cattle), and across three different climatic zones. Grazing reduced structure (by 35%), function (24%), and composition (10%). Structure and function (but not composition) declined more when grazed by sheep and cattle together than sheep alone. Grazing reduced plant biomass (40%), animal richness (15%), and plant and animal abundance, and plant and litter cover (25%), but had no effect on plant richness nor soil function. The negative effects of grazing on plant biomass, plant cover, and soil function were more pronounced in drier environments. Grazing effects on plant and animal richness and composition were constant, or even declined, with increasing aridity. Our study represents a comprehensive continental assessment of the implications of grazing for managing Australian rangelands. Grazing effects were largely negative, even at very low levels of grazing. Overall, our results suggest that livestock grazing in Australia is unlikely to produce positive outcomes for ecosystem structure, function, and composition or even as a blanket conservation tool unless reduction in specific response variables is an explicit management objective. PMID:27509764

  5. Crib sheets and exam performance in a data structures course

    NASA Astrophysics Data System (ADS)

    Hamouda, Sally; Shaffer, Clifford A.

    2016-01-01

    In this paper, we study the relationship between the use of "crib sheets" or "cheat sheets" and performance on in-class exams. Our extensive survey of the existing literature shows that it is not decisive on the questions of when or whether crib sheets actually help students to either perform better on an exam or better learn the material. We report on our own detailed analysis for a body of crib sheets created for the final exam in a junior-level Data Structures and Algorithms course. We wanted to determine whether there is any feature of the crib sheets that correlates to good exam scores. Exam performance was compared against a number of potential indicators for quality in a crib sheet. We have found that students performed significantly better on questions at the comprehension level of Bloom's taxonomy when their crib sheet contained good information on the topic, while performance on questions at higher levels of the taxonomy did not show correlation to crib sheet contents. We have also seen that students at certain levels of performance on the final exam (specifically, medium-to-high performance) did relatively better on certain questions than other students at that performance level when they had good coverage of that question's topic on their crib sheet.

  6. Friction Stir Additive Manufacturing: Route to High Structural Performance

    NASA Astrophysics Data System (ADS)

    Palanivel, S.; Sidhar, H.; Mishra, R. S.

    2015-03-01

    Aerospace and automotive industries provide the next big opportunities for additive manufacturing. Currently, the additive industry is confronted with four major challenges that have been identified in this article. These challenges need to be addressed for the additive technologies to march into new frontiers and create additional markets. Specific potential success in the transportation sectors is dependent on the ability to manufacture complicated structures with high performance. Most of the techniques used for metal-based additive manufacturing are fusion based because of their ability to fulfill the computer-aided design to component vision. Although these techniques aid in fabrication of complex shapes, achieving high structural performance is a key problem due to the liquid-solid phase transformation. In this article, friction stir additive manufacturing (FSAM) is shown as a potential solid-state process for attaining high-performance lightweight alloys for simpler geometrical applications. To illustrate FSAM as a high-performance route, manufactured builds of Mg-4Y-3Nd and AA5083 are shown as examples. In the Mg-based alloy, an average hardness of 120 HV was achieved in the built structure and was significantly higher than that of the base material (97 HV). Similarly for the Al-based alloy, compared with the base hardness of 88 HV, the average built hardness was 104 HV. A potential application of FSAM is illustrated by taking an example of a simple stiffener assembly.

  7. Herbivore species richness and feeding complementarity affect community structure and function on a coral reef

    PubMed Central

    Burkepile, Deron E.; Hay, Mark E.

    2008-01-01

    Consumer effects on prey are well known for cascading through food webs and producing dramatic top-down effects on community structure and ecosystem function. Bottom-up effects of prey (primary producer) biodiversity are also well known. However, the role of consumer diversity in affecting community structure or ecosystem function is not well understood. Here, we show that herbivore species richness can be critical for maintaining the structure and function of coral reefs. In two experiments over 2 years, we constructed large cages enclosing single herbivore species, equal densities of mixed species of herbivores, or excluding herbivores and assessed effects on both seaweeds and corals. When compared with single-herbivore treatments, mixed-herbivore treatments lowered macroalgal abundance by 54–76%, enhanced cover of crustose coralline algae (preferred recruitment sites for corals) by 52–64%, increased coral cover by 22%, and prevented coral mortality. Complementary feeding by herbivorous fishes drove the herbivore richness effects, because macroalgae were unable to effectively deter fishes with different feeding strategies. Maintaining herbivore species richness appears critical for preserving coral reefs, because complementary feeding by diverse herbivores produces positive, but indirect, effects on corals, the foundation species for the ecosystem. PMID:18845686

  8. Vancomycin and maltodextrin affect structure and activity of Staphylococcus aureus biofilms.

    PubMed

    Kiamco, Mia Mae; Atci, Erhan; Khan, Qaiser Farid; Mohamed, Abdelrhman; Renslow, Ryan S; Abu-Lail, Nehal; Fransson, Boel A; Call, Douglas R; Beyenal, Haluk

    2015-12-01

    Hyperosmotic agents such as maltodextrin negatively impact bacterial growth through osmotic stress without contributing to drug resistance. We hypothesized that a combination of maltodextrin (osmotic agent) and vancomycin (antibiotic) would be more effective against Staphylococcus aureus biofilms than either alone. To test our hypothesis, S. aureus was grown in a flat plate flow cell reactor. Confocal laser scanning microscopy images were analyzed to quantify changes in biofilm structure. We used dissolved oxygen microelectrodes to quantify how vancomycin and maltodextrin affected the respiration rate and oxygen penetration into the biofilm. We found that treatment with vancomycin or maltodextrin altered biofilm structure. The effect on the structure was significant when they were used simultaneously to treat S. aureus biofilms. In addition, vancomycin treatment increased the oxygen respiration rate, while maltodextrin treatment caused an increase and then a decrease. An increased maltodextrin concentration decreased the diffusivity of the antibiotic. Overall, we conclude that (1) an increased maltodextrin concentration decreases vancomycin diffusion but increases the osmotic effect, leading to the optimum treatment condition, and (2) the combination of vancomycin and maltodextrin is more effective against S. aureus biofilms than either alone. Vancomycin and maltodextrin act together to increase the effectiveness of treatment against S. aureus biofilm growth. PMID:26084588

  9. Cognitive structure and the affective domain: on knowing and feeling in biology

    NASA Astrophysics Data System (ADS)

    Thompson, Tressa L.; Mintzes, Joel J.

    2002-06-01

    This cross-age study explored the structural complexity and propositional validity of knowledge about and attitudes toward sharks, and the relationships among knowledge and attitudes. Responses were elicited from a convenience sample of students (5th, 8th and 11th grade, and college level) and senior citizens (n = 238). All subjects constructed a concept map on sharks and responded to a Likert-type attitude inventory. Based on the work of Novak and Gowin (Leaning How to Learn, Cambridge University Press, 1984), concept maps were scored for frequencies of non-redundant concepts and scientifically valid relationships, levels of hierarchy, incidence of branching and number of crosslinks. The attitude inventory, emerging from Kellert's (The Value of Life: Biological Diversity and Human Society, Island Press, 1996) work, generated subscale scores on four affective dimensions: scientific, naturalistic, moralistic and utilitarian/negative. Significant differences were found among subject groups on all knowledge structure variables and attitudinal dimensions. Gender differences were documented on three of four attitude subscales. A series of simple, mulitiple and canonical correlations revealed moderately strong relationships between knowledge structure variables and attitudinal dimensions. The pattern of these relationships supports conservation education efforts and instructional practices that encourage meaningful learning, knowledge restructuring and conceptual change (Mintzes et al., Assessing Science Understanding: A Human Constructivist View, Academic Press, 2000).

  10. Brain structural substrates of reward dependence during behavioral performance.

    PubMed

    Dayan, Eran; Hamann, Janne M; Averbeck, Bruno B; Cohen, Leonardo G

    2014-12-01

    Interindividual differences in the effects of reward on performance are prevalent and poorly understood, with some individuals being more dependent than others on the rewarding outcomes of their actions. The origin of this variability in reward dependence is unknown. Here, we tested the relationship between reward dependence and brain structure in healthy humans. Subjects trained on a visuomotor skill-acquisition task and received performance feedback in the presence or absence of reward. Reward dependence was defined as the statistical trial-by-trial relation between reward and subsequent performance. We report a significant relationship between reward dependence and the lateral prefrontal cortex, where regional gray-matter volume predicted reward dependence but not feedback alone. Multivoxel pattern analysis confirmed the anatomical specificity of this relationship. These results identified a likely anatomical marker for the prospective influence of reward on performance, which may be of relevance in neurorehabilitative settings. PMID:25471581

  11. Structure and performance of LiFePO4 cathode materials: A review

    NASA Astrophysics Data System (ADS)

    Zhang, Wei-Jun

    2011-03-01

    LiFePO4 has been considered a promising battery material in electric vehicles. However, there are still a number of technical challenges to overcome before its wide-spread applications. In this article, the structure and electrochemical performance of LiFePO4 are reviewed in light of the major technical requirements for EV batteries. The rate capability, capacity density, cyclic life and low-temperature performance of various LiFePO4 materials are described. The major factors affecting these properties are discussed, which include particle size, doping, carbon coating, conductive carbon loading and synthesis techniques. Important future research for science and engineering is suggested.

  12. How the Structure of Mesoscale Precipitation Systems Affects their Production of Transient Luminous Events

    NASA Astrophysics Data System (ADS)

    Lang, T. J.; Lyons, W.; Rutledge, S. A.; Cummer, S. A.; MacGorman, D. R.

    2011-12-01

    Recently, Lang et al. (2010) analyzed the parent lightning of transient luminous events (TLEs) in the context of the structure and evolution of two mesoscale convective systems (MCSs). These two MCSs were very different - one a giant symmetric leading-line/trailing stratiform storm, and one a small asymmetric MCS that contained a mesoscale convective vortex. These structural differences were associated with substantially different TLE-parent lightning structure as well as TLE production. The results suggested that TLE (especially sprite) production, and TLE-parent positive charge altitude, depend on MCS morphology. Current work is focused on analyzing the structure, evolution, lightning behavior, and TLE production of additional MCSs over various regions of the United States. Several additional TLE-producing MCS cases already have been identified for the years 2008-2010, featuring a variety of organizational modes (symmetric, asymmetric, and other more exotic varieties) in different meteorological regimes (including some cold-season cases). More cases will be incorporated as they occur and are observed. Data sources include geostationary satellite imagery, Doppler radar, three-dimensional lightning mapping networks, ground-strike detection networks, charge moment change measurements, and low-light video observations. The ultimate goal is to further test the hypothesis that MCS structure affects TLE production, and if so to quantify its impact. Research on two Oklahoma case studies, a multicellular system that occurred on 24 March 2009 and a classic bow-echo MCS that occurred on 19 August 2009, is ongoing. Over a 2.5-h period, the March case produced 23 observed TLEs (all sprites) whose parent flashes occurred within 175 km of the Oklahoma Lightning Mapping Array (OKLMA). The median altitude of LMA sources during the TLEs was 5.9 km above Mean Sea Level (MSL), or -19.2 °C. The August storm produced, in 2.5 hours, 34 TLEs (all sprites) with 32 of those having parent

  13. The Relationship between Affective Response to Social Comparison and Academic Performance in High School

    ERIC Educational Resources Information Center

    Wehrens, Maike J. P. W.; Buunk, Abraham P.; Lubbers, Miranda J.; Dijkstra, Pieternel; Kuyper, Hans; van der Werf, Greetje P. C.

    2010-01-01

    The goal of the present study was to study the relationship between affective responses to social comparison and test scores among high school students. Our analyses showed that three types of responses to social comparison could be distinguished: an empathic, constructive, and destructive response. Whereas girls scored higher on empathic…

  14. Nonmusic Majors' Cognitive and Affective Responses to Performance and Programmatic Music Videos.

    ERIC Educational Resources Information Center

    Geringer, John M.; Cassidy, Jane W.; Byo, James L.

    1997-01-01

    Compares the effects of different kinds of visual presentations, and music alone, on university nonmusic students' affective and cognitive responses to music. Separate groups of students listened to classical music excerpts, either by themselves, or with video accompaniment. They rated the music on Likert-type scales and responded to open-ended…

  15. Performance and Attitude of Student Teachers as Affected by Two Grading Systems

    ERIC Educational Resources Information Center

    Clawson, Barbara N.; Scruggs, M. Marguerite

    1974-01-01

    Findings of a study conducted at Iowa State University, Ames, indicated student subjects were not affected by the use of pass-fail grading, and that student teachers were less anxious and more positive about their relationship with their cooperating teachers under pass-fail than under A-F grading. (BP)

  16. Social Structure of Lions (Panthera leo) Is Affected by Management in Pendjari Biosphere Reserve, Benin

    PubMed Central

    Sogbohossou, Etotépé A.; Bauer, Hans; Loveridge, Andrew; Funston, Paul J.; De Snoo, Geert R.; Sinsin, Brice; De Iongh, Hans H.

    2014-01-01

    Lion populations have undergone a severe decline in West Africa. As baseline for conservation management, we assessed the group structure of lions in the Pendjari Biosphere Reserve in Benin. This reserve, composed of one National Park and two Hunting Zones, is part of the WAP transboundary complex of protected areas. Overall mean group size was 2.6±1.7 individuals (n = 296), it was significantly higher in the National Park (2.7±1.7, n = 168) than in the Hunting Zones (2.2±1.5, n = 128). Overall adult sex ratio was even, but significantly biased towards females (0.67) in the National Park and towards males (1.67) in the Hunting Zones. Our results suggest that the Pendjari lion population is affected by perturbations, such as trophy hunting. PMID:24416263

  17. Plant hybrid zones affect biodiversity: Tools for a genetic-based understanding of community structure

    SciTech Connect

    Whitham, T.G.; Martinsen, G.D.; Keim, P.; Floate, K.D.; Dungey, H.S. |; Potts, B.M.

    1999-03-01

    Plant hybrid zones are dynamic centers of ecological and evolutionary processes for plants and their associated communities. Studies in the wild and in gardens with synthetic crosses showed that hybrid eucalypts supports the greatest species richness and abundances of insect and fungal taxa. In an updated review of 152 case studies of taxa associated with diverse hybridizing systems, there were 43 (28%) cases of hybrids being more susceptible than their parent species, 7 (5%) resistant, 35 (23%) additive, 35 (23%) dominant, and 32 (21%) showed no response to hybridization. Thus, most taxa respond to hybrids in ways that result in equal or greater abundance, and hybrids tend to accumulate the taxa of their parent species. These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity.

  18. Cognition-based and affect-based trust as mediators of leader behavior influences on team performance.

    PubMed

    Schaubroeck, John; Lam, Simon S K; Peng, Ann Chunyan

    2011-07-01

    We develop a model in which cognitive and affective trust in the leader mediate the relationship between leader behavior and team psychological states that, in turn, drive team performance. The model is tested on a sample of 191 financial services teams in Hong Kong and the U.S. Servant leadership influenced team performance through affect-based trust and team psychological safety. Transformational leadership influenced team performance indirectly through cognition-based trust. Cognition-based trust directly influenced team potency and indirectly (through affect-based trust) influenced team psychological safety. The effects of leader behavior on team performance were fully mediated through the trust in leader variables and the team psychological states. Servant leadership explained an additional 10% of the variance in team performance beyond the effect of transformational leadership. We discuss implications of these results for research on the relationship between leader behavior and team performance, and for efforts to enhance leader development by combining knowledge from different leadership theories. PMID:21299271

  19. Changes in task-extrinsic context do not affect the persistence of long-term cumulative structural priming.

    PubMed

    Kutta, Timothy J; Kaschak, Michael P

    2012-11-01

    We present two experiments exploring the role of extrinsic memory factors (i.e., factors that are extrinsic to the primary task that is being performed) and intrinsic memory factors (i.e., factors that are intrinsic to the primary task being completed) in the persistence of cumulative structural priming effects. Participants completed a two-phase experiment, where the first phase established a bias toward producing either the double object or prepositional object construction, and the second phase assessed the effects of this bias. Extrinsic memory factors were manipulated by having participants complete the two phases of the study in the same or different locations (physical context change) or while watching the same or different videos (video context change). Participants completed the second phase of the study 10 min after the first phase of the study in Experiment 1, and after a delay of 1 week in Experiment 2. Results suggest that the observed structural priming effects were not affected by manipulations of extrinsic memory factors. These data suggest that explicit memory does not play a large role in the long-term persistence of cumulative structural priming effects. PMID:23103416

  20. Affect, Behavior, Cognition, and Desire in the Big Five: An Analysis of Item Content and Structure

    PubMed Central

    Wilt, Joshua; Revelle, William

    2015-01-01

    Personality psychology is concerned with affect (A), behavior (B), cognition (C) and desire (D), and personality traits have been defined conceptually as abstractions used to either explain or summarize coherent ABC (and sometimes D) patterns over time and space. However, this conceptual definition of traits has not been reflected in their operationalization, possibly resulting in theoretical and practical limitations to current trait inventories. Thus, the goal of this project was to determine the affective, behavioral, cognitive and desire (ABCD) components of Big-Five personality traits. The first study assessed the ABCD content of items measuring Big-Five traits in order to determine the ABCD composition of traits and identify items measuring relatively high amounts of only one ABCD content. The second study examined the correlational structure of scales constructed from items assessing ABCD content via a large, web-based study. An assessment of Big-Five traits that delineates ABCD components of each trait is presented, and the discussion focuses on how this assessment builds upon current approaches of assessing personality. PMID:26279606

  1. Spatial and spatiotemporal variation in metapopulation structure affects population dynamics in a passively dispersing arthropod.

    PubMed

    De Roissart, Annelies; Wang, Shaopeng; Bonte, Dries

    2015-11-01

    The spatial and temporal variation in the availability of suitable habitat within metapopulations determines colonization-extinction events, regulates local population sizes and eventually affects local population and metapopulation stability. Insights into the impact of such a spatiotemporal variation on the local population and metapopulation dynamics are principally derived from classical metapopulation theory and have not been experimentally validated. By manipulating spatial structure in artificial metapopulations of the spider mite Tetranychus urticae, we test to which degree spatial (mainland-island metapopulations) and spatiotemporal variation (classical metapopulations) in habitat availability affects the dynamics of the metapopulations relative to systems where habitat is constantly available in time and space (patchy metapopulations). Our experiment demonstrates that (i) spatial variation in habitat availability decreases variance in metapopulation size and decreases density-dependent dispersal at the metapopulation level, while (ii) spatiotemporal variation in habitat availability increases patch extinction rates, decreases local population and metapopulation sizes and decreases density dependence in population growth rates. We found dispersal to be negatively density dependent and overall low in the spatial variable mainland-island metapopulation. This demographic variation subsequently impacts local and regional population dynamics and determines patterns of metapopulation stability. Both local and metapopulation-level variabilities are minimized in mainland-island metapopulations relative to classical and patchy ones. PMID:25988264

  2. Structural study of skeletal muscle fibres in healthy and pseudomyotonia affected cattle.

    PubMed

    Mascarello, Francesco; Sacchetto, Roberta

    2016-09-01

    Cattle congenital pseudomyotonia (PMT), recognized as naturally occurring animal model of human Brody disease, is an inherited recessive autosomal muscular disorder due to missense mutations in ATP2A1 gene, encoding sarco(endo)plasmic reticulum Ca(2+)-ATPase protein, isoform 1 (SERCA1). PMT has been described in the Chianina and Romagnola italian cattle breeds and as a single case in Dutch improved Red and White cross-breed. The genetic defect turned out to be heterogeneous in different cattle breeds, even though clinical symptoms were homogeneous. Skeletal muscles of affected animals are characterized by a selective deficiency of SERCA1 in sarcoplasmic reticulum (SR) membranes. Recently, we provided evidence that in Chianina breed, the ubiquitin proteasome system is responsible for SERCA1 mutant premature disposal, even when the mutation does not affect the catalytic properties of the pump. Results presented here show that all SERCA1 mutants described until now, although expressed at low level, are correctly targeted to SR membranes. Ultrastructural studies confirm that in pathological muscle fibres, structure, as well as triads, is well preserved. All together these results suggest that a possible therapeutical approach based on the rescue of the defective protein at SR membranes could be hypothesized. Only fully functionally active missense mutants, whem located at the SR membrane could restore the efficient control of Ca(2+) homeostasis and prevent the appearance of the pathological signs. Moreover, these data demonstrate the increasing importance of domestic animals as genetic models of human pathologies. PMID:27210062

  3. Alternative S2 Hinge Regions of the Myosin Rod Affect Myofibrillar Structure and Myosin Kinetics

    PubMed Central

    Miller, Mark S.; Dambacher, Corey M.; Knowles, Aileen F.; Braddock, Joan M.; Farman, Gerrie P.; Irving, Thomas C.; Swank, Douglas M.; Bernstein, Sanford I.; Maughan, David W.

    2009-01-01

    The subfragment 2/light meromyosin “hinge” region has been proposed to significantly contribute to muscle contraction force and/or speed. Transgenic replacement of the endogenous fast muscle isovariant hinge A (exon 15a) in Drosophila melanogaster indirect flight muscle with the slow muscle hinge B (exon 15b) allows examination of the structural and functional changes when only this region of the myosin molecule is different. Hinge B was previously shown to increase myosin rod length, increase A-band and sarcomere length, and decrease flight performance compared to hinge A. We applied additional measures to these transgenic lines to further evaluate the consequences of modifying this hinge region. Structurally, the longer A-band and sarcomere lengths found in the hinge B myofibrils appear to be due to the longitudinal addition of myosin heads. Functionally, hinge B, although a significant distance from the myosin catalytic domain, alters myosin kinetics in a manner consistent with this region increasing myosin rod length. These structural and functional changes combine to decrease whole fly wing-beat frequency and flight performance. Our results indicate that this hinge region plays an important role in determining myosin kinetics and in regulating thick and thin filament lengths as well as sarcomere length. PMID:19450484

  4. Alternative S2 Hinge Regions of the Myosin Rod Affect Myofibrillar Structure and Myosin Kinetics

    SciTech Connect

    Miller, Mark S.; Dambacher, Corey M.; Knowles, Aileen F.; Braddock, Joan M.; Farman, Gerrie P.; Irving, Thomas C.; Swank, Douglas M.; Bernstein, Sanford I.; Maughan, David W.

    2009-07-01

    The subfragment 2/light meromyosin 'hinge' region has been proposed to significantly contribute to muscle contraction force and/or speed. Transgenic replacement of the endogenous fast muscle isovariant hinge A (exon 15a) in Drosophila melanogaster indirect flight muscle with the slow muscle hinge B (exon 15b) allows examination of the structural and functional changes when only this region of the myosin molecule is different. Hinge B was previously shown to increase myosin rod length, increase A-band and sarcomere length, and decrease flight performance compared to hinge A. We applied additional measures to these transgenic lines to further evaluate the consequences of modifying this hinge region. Structurally, the longer A-band and sarcomere lengths found in the hinge B myofibrils appear to be due to the longitudinal addition of myosin heads. Functionally, hinge B, although a significant distance from the myosin catalytic domain, alters myosin kinetics in a manner consistent with this region increasing myosin rod length. These structural and functional changes combine to decrease whole fly wing-beat frequency and flight performance. Our results indicate that this hinge region plays an important role in determining myosin kinetics and in regulating thick and thin filament lengths as well as sarcomere length.

  5. Do candidate reactions relate to job performance or affect criterion-related validity? A multistudy investigation of relations among reactions, selection test scores, and job performance.

    PubMed

    McCarthy, Julie M; Van Iddekinge, Chad H; Lievens, Filip; Kung, Mei-Chuan; Sinar, Evan F; Campion, Michael A

    2013-09-01

    Considerable evidence suggests that how candidates react to selection procedures can affect their test performance and their attitudes toward the hiring organization (e.g., recommending the firm to others). However, very few studies of candidate reactions have examined one of the outcomes organizations care most about: job performance. We attempt to address this gap by developing and testing a conceptual framework that delineates whether and how candidate reactions might influence job performance. We accomplish this objective using data from 4 studies (total N = 6,480), 6 selection procedures (personality tests, job knowledge tests, cognitive ability tests, work samples, situational judgment tests, and a selection inventory), 5 key candidate reactions (anxiety, motivation, belief in tests, self-efficacy, and procedural justice), 2 contexts (industry and education), 3 continents (North America, South America, and Europe), 2 study designs (predictive and concurrent), and 4 occupational areas (medical, sales, customer service, and technological). Consistent with previous research, candidate reactions were related to test scores, and test scores were related to job performance. Further, there was some evidence that reactions affected performance indirectly through their influence on test scores. Finally, in no cases did candidate reactions affect the prediction of job performance by increasing or decreasing the criterion-related validity of test scores. Implications of these findings and avenues for future research are discussed. PMID:23937298

  6. To What Degree Does Provider Performance Affect a Quality Indicator? The Case of Nursing Homes and ADL Change

    ERIC Educational Resources Information Center

    Phillips, Charles D.; Chen, Min; Sherman, Michael

    2008-01-01

    Purpose: This research investigates what factors affect the degree to which nursing home performance explains variance in residents' change in status of activities of daily living (ADL) after admission. Design and Methods: The database included all residents admitted in 2002 to a 10% random sample of nursing homes in the United States.…

  7. Determining the Factors That Affect the Objectives of Pre-Service Science Teachers to Perform Outdoor Science Activities

    ERIC Educational Resources Information Center

    Karademir, Ersin; Erten, Sinan

    2013-01-01

    The purpose of this study is to determine whether pre-service teachers have an aim to perform outdoor education activities within the scope of science and technology course; by which factors this aim is affected, through The Theory of Planned Behaviour and the opinions of pre-service teachers. Accordingly, the study was designed as mixed research…

  8. Effects of musical tempo on physiological, affective, and perceptual variables and performance of self-selected walking pace

    PubMed Central

    Almeida, Flávia Angélica Martins; Nunes, Renan Felipe Hartmann; Ferreira, Sandro dos Santos; Krinski, Kleverton; Elsangedy, Hassan Mohamed; Buzzachera, Cosme Franklin; Alves, Ragami Chaves; Gregorio da Silva, Sergio

    2015-01-01

    [Purpose] This study investigated the effects of musical tempo on physiological, affective, and perceptual responses as well as the performance of self-selected walking pace. [Subjects] The study included 28 adult women between 29 and 51 years old. [Methods] The subjects were divided into three groups: no musical stimulation group (control), and 90 and 140 beats per minute musical tempo groups. Each subject underwent three experimental sessions: involved familiarization with the equipment, an incremental test to exhaustion, and a 30-min walk on a treadmill at a self-selected pace, respectively. During the self-selected walking session, physiological, perceptual, and affective variables were evaluated, and walking performance was evaluated at the end. [Results] There were no significant differences in physiological variables or affective response among groups. However, there were significant differences in perceptual response and walking performance among groups. [Conclusion] Fast music (140 beats per minute) promotes a higher rating of perceived exertion and greater performance in self-selected walking pace without significantly altering physiological variables or affective response. PMID:26180303

  9. Teacher Discourse and Sixth Graders' Reported Affect and Achievement Behaviors in Two High-Mastery/High-Performance Mathematics Classrooms.

    ERIC Educational Resources Information Center

    Turner, Julianne C.; Meyer, Debra K.; Midgley, Carol; Patrick, Helen

    2003-01-01

    Examined the relation between the nature of teacher discourse and sixth-grade students' reports of affect and behavior in mathematics classrooms students perceived as emphasizing both mastery and performance goals. Found that students in the classroom in which there was constant and explicit support for autonomy and intrinsic motivation, positive…

  10. Effects of musical tempo on physiological, affective, and perceptual variables and performance of self-selected walking pace.

    PubMed

    Almeida, Flávia Angélica Martins; Nunes, Renan Felipe Hartmann; Ferreira, Sandro Dos Santos; Krinski, Kleverton; Elsangedy, Hassan Mohamed; Buzzachera, Cosme Franklin; Alves, Ragami Chaves; Gregorio da Silva, Sergio

    2015-06-01

    [Purpose] This study investigated the effects of musical tempo on physiological, affective, and perceptual responses as well as the performance of self-selected walking pace. [Subjects] The study included 28 adult women between 29 and 51 years old. [Methods] The subjects were divided into three groups: no musical stimulation group (control), and 90 and 140 beats per minute musical tempo groups. Each subject underwent three experimental sessions: involved familiarization with the equipment, an incremental test to exhaustion, and a 30-min walk on a treadmill at a self-selected pace, respectively. During the self-selected walking session, physiological, perceptual, and affective variables were evaluated, and walking performance was evaluated at the end. [Results] There were no significant differences in physiological variables or affective response among groups. However, there were significant differences in perceptual response and walking performance among groups. [Conclusion] Fast music (140 beats per minute) promotes a higher rating of perceived exertion and greater performance in self-selected walking pace without significantly altering physiological variables or affective response. PMID:26180303

  11. Does body size affect a bird's sensitivity to patch size and landscape structure?

    USGS Publications Warehouse

    Winter, M.; Johnson, D.H.; Shaffer, J.A.

    2006-01-01

    Larger birds are generally more strongly affected by habitat loss and fragmentation than are smaller ones because they require more resources and thus larger habitat patches. Consequently, conservation actions often favor the creation or protection of larger over smaller patches. However, in grassland systems the boundaries between a patch and the surrounding landscape, and thus the perceived size of a patch, can be indistinct. We investigated whether eight grassland bird species with different body sizes perceived variation in patch size and landscape structure in a consistent manner. Data were collected from surveys conducted in 44 patches of northern tallgrass prairie during 1998-2001. The response to patch size was very similar among species regardless of body size (density was little affected by patch size), except in the Greater Prairie-Chicken (Tympanuchus cupido), which showed a threshold effect and was not found in patches smaller than 140 ha. In landscapes containing 0%-30% woody vegetation, smaller species responded more negatively to increases in the percentage of woody vegetation than larger species, but above an apparent threshold of 30%, larger species were not detected. Further analyses revealed that the observed variation in responses to patch size and landscape structure among species was not solely due to body size per se, but to other differences among species. These results indicate that a stringent application of concepts requiring larger habitat patches for larger species appears to limit the number of grassland habitats that can be protected and may not always be the most effective conservation strategy. ?? The Cooper Ornithological Society 2006.

  12. Moisture and Structural Analysis for High Performance Hybrid Wall Assemblies

    SciTech Connect

    Grin, A.; Lstiburek, J.

    2012-09-01

    Based on past experience in the Building America program, BSC has found that combinations of materials and approaches—in other words, systems—usually provide optimum performance. Integration is necessary, as described in this research project. The hybrid walls analyzed utilize a combination of exterior insulation, diagonal metal strapping, and spray polyurethane foam and leave room for cavity-fill insulation. These systems can provide effective thermal, air, moisture, and water barrier systems in one assembly and provide structure.

  13. Brain Functional and Structural Predictors of Language Performance.

    PubMed

    Skeide, Michael A; Brauer, Jens; Friederici, Angela D

    2016-05-01

    The relation between brain function and behavior on the one hand and the relation between structural changes and behavior on the other as well as the link between the 2 aspects are core issues in cognitive neuroscience. It is an open question, however, whether brain function or brain structure is the better predictor for age-specific cognitive performance. Here, in a comprehensive set of analyses, we investigated the direct relation between hemodynamic activity in 2 pairs of frontal and temporal cortical areas, 2 long-distance white matter fiber tracts connecting each pair and sentence comprehension performance of 4 age groups, including 3 groups of children between 3 and 10 years as well as young adults. We show that the increasing accuracy of processing complex sentences throughout development is correlated with the blood-oxygen-level-dependent activation of 2 core language processing regions in Broca's area and the posterior portion of the superior temporal gyrus. Moreover, both accuracy and speed of processing are correlated with the maturational status of the arcuate fasciculus, that is, the dorsal white matter fiber bundle connecting these 2 regions. The present data provide compelling evidence for the view that brain function and white matter structure together best predict developing cognitive performance. PMID:25770126

  14. Cortical structure predicts success in performing musical transformation judgments.

    PubMed

    Foster, Nicholas E V; Zatorre, Robert J

    2010-10-15

    Recognizing melodies by their interval structure, or "relative pitch," is a fundamental aspect of musical perception. By using relative pitch, we are able to recognize tunes regardless of the key in which they are played. We sought to determine the cortical areas important for relative pitch processing using two morphometric techniques. Cortical differences have been reported in musicians within right auditory cortex (AC), a region considered important for pitch-based processing, and we have previously reported a functional correlation between relative pitch processing in the anterior intraparietal sulcus (IPS). We addressed the hypothesis that regional variation of cortical structure within AC and IPS is related to relative pitch ability using two anatomical techniques, cortical thickness (CT) analysis and voxel-based morphometry (VBM) of magnetic resonance imaging data. Persons with variable amounts of formal musical training were tested on a melody transposition task, as well as two musical control tasks and a speech control task. We found that gray matter concentration and cortical thickness in right Heschl's sulcus and bilateral IPS both predicted relative pitch task performance and correlated to a lesser extent with performance on the two musical control tasks. After factoring out variance explained by musical training, only relative pitch performance was predicted by cortical structure in these regions. These results directly demonstrate the functional relevance of previously reported anatomical differences in the auditory cortex of musicians. The findings in the IPS provide further support for the existence of a multimodal network for systematic transformation of stimulus information in this region. PMID:20600982

  15. Ert Applied to the Characterization of Subsidence in Mexico City: Ancient Structures Affecting Urban Utilities

    NASA Astrophysics Data System (ADS)

    Arango, C.; Chavez, R. E.; Cifuentes-Nava, G.; Hernández-Quintero, E.

    2013-05-01

    The problem of subsidence in Mexico City is basically due to the rapid extraction of groundwater for water supply in addition to the geological conditions. The most typical manifestations of the phenomena are presented as cracks and fractures due to compaction of ancient lake clayish sediments. This phenomenon has caused major affectations to city infrastructure because of the differential subsidence. Fractured buildings, sinkholes, among others manifestations, are potentially sources of collapses, which exposes the population to a serious risk. A small portion of Iztacalco County is being affected by this problem, specifically, in a crossroad formed by two important avenues: La Viga and Plutarco Elias Calles, where the area apparently increases its topographical level. The Electrical Resistivity Tomography technique was selected in order to obtain a resistivity image of the subsoil, which allows identify the main features associated to the terrain uprising. Three (ERT) profiles 200 m, were deployed on the mentioned crossroad in order to characterize the subsurface structures affecting the topographical level of the avenues. A big resistivity anomaly (~ 1000 ohm-m) could be observed towards the central part of the crossroad, coinciding with the major lifting level on surface. This feature appears at 15 m deep in all the profiles and depicts an approximate extension of 100 m in the E-W direction and 60 m in N-S axis. On the other hand, the surrounding material seems to correspond to a higher-saturated environment (lacustrine sediments <10 ohm-m). Shallow anomalies were also detected related to urban artifacts (pipes, sewers, etcetera). The apparently terrain uprising can be associated to a differential subsidence. However, the mentioned avenues were ancient water channels since pre-Hispanic times, where the caudal was enough to allow small steam boating at late nineteenth century. These waterways served as main routes for the exchange of goods during colonial times

  16. Do Content Area Passages Affect Student Performance on Reading Comprehension Tests?

    ERIC Educational Resources Information Center

    Peretz, Arna S.

    A study conducted in Israel investigated the relevance of subject-specific reading passages to performance on reading comprehension tests for advanced university students of English as a second language. The research specifically examined (1) whether students performed better when the reading test content was directly related to their field of…

  17. Factors Affecting Spatial Test Performance: Sex, Handedness, Birth Order, and Experience.

    ERIC Educational Resources Information Center

    Guay, Roland B.

    Four factors have been reported in the literature as being related to spatial test performance. This study investigated the main and interaction effects of sex, handedness, birth order, and experience on three different types of spatial performance; surface development, object rotation, and coordination of viewpoints. A total of 217 undergraduate…

  18. Breast screening technologists: Does real-life case volume affect performance?

    NASA Astrophysics Data System (ADS)

    Scott, Hazel J.; Gale, Alastair G.; Wooding, David S.

    2004-05-01

    In the UK fewer radiologists are now specialising in breast cancer screening. Consequently, a number of technologists have been specially trained to read mammograms so as to double-read with existing radiologists. Each year the majority of these film-readers examine a set of difficult cases as a means of self-assessing their skills. We investigated whether the technologists performed as well as breast-screening radiologists on this difficult test set. We also investigated technologists" performance over a number of years to compare the performance of those technologists who have read a greater number of breast screening films and those who have had less experience. Finally, we investigated real-life experience and performance on the scheme by comparing; volume of cases read, experience, and technologists" performance over time versus radiologists" performance. Data for approximately 250 breast screening Radiologists and 80 specially trained technologists over three years for six sets of 60 difficult recent screening cases were examined. Overall, those technologists who have not read the same volume of cases as radiologists did not perform as well on this particular task. Although when the group was fractionated by volume of cases read in real-life and the number of years reading cases, then the technologists performed at a level similar to the radiologists.

  19. Structure of high-performance evaporators for space application.

    PubMed

    Ohta, Haruhiko; Shinmoto, Yasuhisa; Mizukoshi, Toshiyuki; Ishikawa, Yosuke

    2006-09-01

    A new structure of cold plates, where an unheated auxiliary channel is installed to supply liquid directly to the bottom of coalesced flattened bubbles in a narrow heated channel, is tested to investigate the increase in critical heat flux. Assuming the application to the laser solar power system, a large heating surface with a length of 150 mm in the flow direction is employed, and a narrow channel structure is adopted to reduce the size of cold plates, where the gap sizes are selected as 5 mm and 2 mm. Experiments are performed for water as a test liquid at inlet subcooling of 15 K under near atmospheric pressure. Inlet liquid velocity is varied from 0.065 m/s to 0.6m/s for the upward flow on ground. A value of critical heat flux of 2.2 x 10(6) W/m2 is obtained for 5-mm gap size at the inlet velocity of 0.2 m/s. At low liquid flow rate, the structure realizes the CHF values larger by 2.5 times than those for the normal heated channel without additional liquid supply. A new method to evaluate the performance of cold plates is proposed to take account of the variation in the size of heating surface, inlet liquid velocity, and subcooling that influence the CHF values. The validity of the proposed structure of the cold plate for the increase in critical heat flux is confirmed. PMID:17124151

  20. Blocking and detection chemistries affect antibody performance on reverse phase protein arrays.

    PubMed

    Ambroz, Kristi L H; Zhang, Yonghong; Schutz-Geschwender, Amy; Olive, D Michael

    2008-06-01

    Antibody specificity is critical for RP protein arrays (RPA). The effects of blocking and detection chemistries on antibody specificity were evaluated for Western blots and RPA. Blocking buffers significantly affected nonspecific banding on Western blots, with corresponding effects on arrays. Tyramide signal amplification (TSA) increased both specific and nonspecific signals on Westerns and arrays, masking the expected gradations in signal intensity. These results suggest that consistent blocking and detection conditions should be used for antibody validation and subsequent RPA experiments. PMID:18563731

  1. Elevated CO2 Affects Predator-Prey Interactions through Altered Performance

    PubMed Central

    Allan, Bridie J. M.; Domenici, Paolo; McCormick, Mark I.; Watson, Sue-Ann; Munday, Philip L.

    2013-01-01

    Recent research has shown that exposure to elevated carbon dioxide (CO2) affects how fishes perceive their environment, affecting behavioral and cognitive processes leading to increased prey mortality. However, it is unclear if increased mortality results from changes in the dynamics of predator-prey interactions or due to prey increasing activity levels. Here we demonstrate that ocean pCO2 projected to occur by 2100 significantly effects the interactions of a predator-prey pair of common reef fish: the planktivorous damselfish Pomacentrus amboinensis and the piscivorous dottyback Pseudochromis fuscus. Prey exposed to elevated CO2 (880 µatm) or a present-day control (440 µatm) interacted with similarly exposed predators in a cross-factored design. Predators had the lowest capture success when exposed to elevated CO2 and interacting with prey exposed to present-day CO2. Prey exposed to elevated CO2 had reduced escape distances and longer reaction distances compared to prey exposed to present-day CO2 conditions, but this was dependent on whether the prey was paired with a CO2 exposed predator or not. This suggests that the dynamics of predator-prey interactions under future CO2 environments will depend on the extent to which the interacting species are affected and can adapt to the adverse effects of elevated CO2. PMID:23484032

  2. An Analysis of the Structural Factors Affecting the Public Participation in Health Promotion

    PubMed Central

    Ghaumi, Raheleh; Aminee, Tayebe; Aminaee, Akram; Dastoury, Mojgan

    2016-01-01

    The present study focuses on analyzing national and international Community-Based Participatory Research (CBPR) studies published from 2000 to 2012 in order to identify and categorize the possible factors that affect social participation for improving the public health. Clearly, improving the public health necessitates a combination of the participation and responsibility by the social members and the attempts by public health policy-makers and planners. CBPR studies are selected as the corpus since they seek to encourage active and informed participation of the social members in fulfilling the health related goals. The present study is conducted through meta-synthesis within a qualitative framework. The results revealed a set of factors within the structural capacities which were employed by the CBPR researchers for achieving the health promotion goals. The structural capacities employed in the interventions could be considered on the cultural and social grounds. The cultural grounds were divided into scientific and religious attempts. For the scientific attempts, the results highlighted the participation of higher education institutes including universities and research centers as well as educational institutes such as schools and the relevant institutions. And regarding the religious attempts, the results indicated that the cooptation of religious centers played the greatest role in enhancing the public participation. PMID:27045401

  3. Ontogenetic shifts in plant interactions vary with environmental severity and affect population structure.

    PubMed

    le Roux, Peter C; Shaw, Justine D; Chown, Steven L

    2013-10-01

    Environmental conditions and plant size may both alter the outcome of inter-specific plant-plant interactions, with seedlings generally facilitated more strongly than larger individuals in stressful habitats. However, the combined impact of plant size and environmental severity on interactions is poorly understood. Here, we tested explicitly for the first time the hypothesis that ontogenetic shifts in interactions are delayed under increasingly severe conditions by examining the interaction between a grass, Agrostis magellanica, and a cushion plant, Azorella selago, along two severity gradients. The impact of A. selago on A. magellanica abundance, but not reproductive effort, was related to A. magellanica size, with a trend for delayed shifts towards more negative interactions under greater environmental severity. Intermediate-sized individuals were most strongly facilitated, leading to differences in the size-class distribution of A. magellanica on the soil and on A. selago. The A. magellanica size-class distribution was more strongly affected by A. selago than by environmental severity, demonstrating that the plant-plant interaction impacts A. magellanica population structure more strongly than habitat conditions. As ontogenetic shifts in plant-plant interactions cannot be assumed to be constant across severity gradients and may impact species population structure, studies examining the outcome of interactions need to consider the potential for size- or age-related variation in competition and facilitation. PMID:23738758

  4. Ubiquitin Ser65 phosphorylation affects ubiquitin structure, chain assembly and hydrolysis

    PubMed Central

    Wauer, Tobias; Swatek, Kirby N; Wagstaff, Jane L; Gladkova, Christina; Pruneda, Jonathan N; Michel, Martin A; Gersch, Malte; Johnson, Christopher M; Freund, Stefan MV; Komander, David

    2015-01-01

    The protein kinase PINK1 was recently shown to phosphorylate ubiquitin (Ub) on Ser65, and phosphoUb activates the E3 ligase Parkin allosterically. Here, we show that PINK1 can phosphorylate every Ub in Ub chains. Moreover, Ser65 phosphorylation alters Ub structure, generating two conformations in solution. A crystal structure of the major conformation resembles Ub but has altered surface properties. NMR reveals a second phosphoUb conformation in which β5-strand slippage retracts the C-terminal tail by two residues into the Ub core. We further show that phosphoUb has no effect on E1-mediated E2 charging but can affect discharging of E2 enzymes to form polyUb chains. Notably, UBE2R1- (CDC34), UBE2N/UBE2V1- (UBC13/UEV1A), TRAF6- and HOIP-mediated chain assembly is inhibited by phosphoUb. While Lys63-linked poly-phosphoUb is recognized by the TAB2 NZF Ub binding domain (UBD), 10 out of 12 deubiquitinases (DUBs), including USP8, USP15 and USP30, are impaired in hydrolyzing phosphoUb chains. Hence, Ub phosphorylation has repercussions for ubiquitination and deubiquitination cascades beyond Parkin activation and may provide an independent layer of regulation in the Ub system. PMID:25527291

  5. An Analysis of the Structural Factors Affecting the Public Participation in Health Promotion.

    PubMed

    Ghaumi, Raheleh; Aminee, Tayebe; Aminaee, Akram; Dastoury, Mojgan

    2016-01-01

    The present study focuses on analyzing national and international Community-Based Participatory Research (CBPR) studies published from 2000 to 2010 in order to identify and categorize the possible factors that affect social participation for improving the public health. Clearly, improving the public health necessitates a combination of the participation and responsibility by the social members and the attempts by public health policy-makers and planners. CBPR studies are selected as the corpus since they seek to encourage active and informed participation of the social members in fulfilling the health related goals. The present study is conducted through meta-synthesis within a qualitative framework. The results revealed a set of factors within the structural capacities which were employed by the CBPR researchers for achieving the health promotion goals. The structural capacities employed in the interventions could be considered on the cultural and social grounds. The cultural grounds were divided into scientific and religious attempts. For the scientific attempts, the results highlighted the participation of higher education institutes including universities and research centers as well as educational institutes such as schools and the relevant institutions. And regarding the religious attempts, the results indicated that the cooptation of religious centers played the greatest role in enhancing the public participation. PMID:27045401

  6. Performance categorization of structures, systems & components and related issues

    SciTech Connect

    Hossain, Q.A.

    1993-09-30

    Provisions of DOE-STD-1021-93 on performance categorization of structures, systems and components (SSCs) subjected to natural phenomena hazards (NPHs) are summarized. The interrelationship among safety classification of SSCs (per DOE 6430.1A and DOE 5480.30), facility hazard categorization/classification (per DOE 5481.1B and DOE 5480.23), and NPH performance categorization of SSCs (per DOE 5480.28 and DOE-STD-1021-93) is discussed. The compatibility between the safety goals in the Department of Energy Safety Policy, SEN-35-91, and the numerical NPH performance goals of DOE 5480.28, as presented in UCRL-ID-12612 (draft), is examined.

  7. Space Environment Factors Affecting the Performance of International Space Station Materials: The First Two Years of Flight Operations

    NASA Technical Reports Server (NTRS)

    Koontz, Steven L.; Peldey, Michael; Mayeaux, Brian; Milkatarian, Ronald R.; Golden, John; Boeder, paul; Kern, John; Barsamian, Hagop; Alred, John; Soares, Carlos; Christiansen, Eric; Schneider, Todd; Edwards, Dave

    2003-01-01

    In this paper, the natural and induced space environment factors affecting materials performance on ISS are described in some detail. The emphasis will be on ISS flight experience and the more significant design and development issues of the last two years. The intent is to identify and document the set of space environment factors, affecting materials, that are producing the largest impacts on the ISS flight hardware verification and acceptance process and on ISS flight operations. Orbital inclination (S1.6 ) and altitude (nominal3S0 km to 400 km altitude) determine the set of natural environment factors affecting the functional life of materials and subsystems on ISS. ISS operates in the F2 region of Earth's ionosphere in well-defined fluxes of atomic oxygen, other ionospheric plasma species, and solar UV, VUV, and x-ray radiation, as well as galactic cosmic rays, trapped radiation, and solar cosmic rays (1,2). The high latitude orbital environment also exposes external surfaces to significantly less well-defined or predictable fluxes of higher energy trapped electrons and auroral electrons (3 ,4). The micrometeoroid and orbital debris environment is an important determinant of spacecraft design and operations in any orbital inclination. Environment factors induced by ISS flight operations include ram-wake effects, magnetic induction voltages arising from flight through Earth's magnetic field, hypergolic thruster plume impingement from proximity operations of visiting vehicles, materials outgassing, venting and dumping of fluids, ISS thruster operations, as well as specific electrical power system interactions with the ionospheric plasma (S-7). ISS must fly in a very limited number of approved flight attitudes leading to location specific environmental exposures and extreme local thermal environments (8). ISS is a large vehicle and produces a deep wake structure from which both ionospheric plasma and neutrals (atomic oxygen) are largely excluded (9-11). At high

  8. Do senior management cultures affect performance? Evidence from Italian public healthcare organizations.

    PubMed

    Prenestini, Anna; Lega, Federico

    2013-01-01

    Healthcare organizations are often characterized by diffuse power, ambiguous goals, and a plurality of actors. In this complex and pluralistic context, senior healthcare managers are expected to provide strategic direction and lead their organizations toward their goals and performance targets. The present work explores the relationship between senior management team culture and performance by investigating Italian public healthcare organizations in the Tuscany region. Our assessment of senior management culture was accomplished through the use of an established framework and a corresponding tool, the competing values framework, which supports the idea that specific aspects of performance are related to a dominant management culture. Organizational performance was assessed using a wide range of measures collected by a multidimensional performance evaluation system, which was developed in Tuscany to measure the performance of its 12 local health authorities (LHAs) and four teaching hospitals (THs). Usable responses were received from 80 senior managers of 11 different healthcare organizations (two THs and nine LHAs). Our findings show that Tuscan healthcare organizations are characterized by various dominant cultures: developmental, clan, rational, and hierarchical. These variations in dominant culture were associated with performance measures. The implications for management theory, professional practice, and public policy are discussed. PMID:24195342

  9. Cognitive and Tactile Factors Affecting Human Haptic Performance in Later Life

    PubMed Central

    Kalisch, Tobias; Kattenstroth, Jan-Christoph; Kowalewski, Rebecca; Tegenthoff, Martin; Dinse, Hubert R.

    2012-01-01

    Background Vision and haptics are the key modalities by which humans perceive objects and interact with their environment in a target-oriented manner. Both modalities share higher-order neural resources and the mechanisms required for object exploration. Compared to vision, the understanding of haptic information processing is still rudimentary. Although it is known that haptic performance, similar to many other skills, decreases in old age, the underlying mechanisms are not clear. It is yet to be determined to what extent this decrease is related to the age-related loss of tactile acuity or cognitive capacity. Methodology/Principal Findings We investigated the haptic performance of 81 older adults by means of a cross-modal object recognition test. Additionally, we assessed the subjects' tactile acuity with an apparatus-based two-point discrimination paradigm, and their cognitive performance by means of the non-verbal Raven-Standard-Progressive matrices test. As expected, there was a significant age-related decline in performance on all 3 tests. With the exception of tactile acuity, this decline was found to be more distinct in female subjects. Correlation analyses revealed a strong relationship between haptic and cognitive performance for all subjects. Tactile performance, on the contrary, was only significantly correlated with male subjects' haptic performance. Conclusions Haptic object recognition is a demanding task in old age, especially when it comes to the exploration of complex, unfamiliar objects. Our data support a disproportionately higher impact of cognition on haptic performance as compared to the impact of tactile acuity. Our findings are in agreement with studies reporting an increase in co-variation between individual sensory performance and general cognitive functioning in old age. PMID:22291952

  10. Factors affecting swimming performance of fasted rainbow trout with implications of exhaustive exercise on overwinter mortality

    USGS Publications Warehouse

    Simpkins, D.G.; Hubert, W.A.; Del Rio, C.M.; Rule, D.C.

    2004-01-01

    We evaluated the effects of body size, water temperature, and sustained swimming activity on swimming performance and the effects of exhaustive exercise on mortality of fasted juvenile rainbow trout. Fasting caused swimming performance to decline more rapidly for small fish than large fish, and warmer water temperatures and sustained swimming activity further decreased swimming performance. Exhaustive exercise increased mortality among fasted fish. Our observations suggest that juvenile rainbow trout with little or no food intake during winter can swim for long periods of time with little effect on mortality, but swimming to exhaustion can enhance mortality, especially among the smallest juveniles.

  11. Remnant Trees Affect Species Composition but Not Structure of Tropical Second-Growth Forest

    PubMed Central

    Sandor, Manette E.; Chazdon, Robin L.

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2–3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests (“control plots”). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields. PMID:24454700

  12. Factors affecting the alkaline cooking performance of selected corn and sorghum hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dent corn (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) sample sets representative of commonly grown hybrids and diverse physical attributes were analyzed for nixtamalization performance. The influence of kernel characteristics including hardness, density, starch properties (thermal, pasting...

  13. Human factors with nonhumans - Factors that affect computer-task performance

    NASA Technical Reports Server (NTRS)

    Washburn, David A.

    1992-01-01

    There are two general strategies that may be employed for 'doing human factors research with nonhuman animals'. First, one may use the methods of traditional human factors investigations to examine the nonhuman animal-to-machine interface. Alternatively, one might use performance by nonhuman animals as a surrogate for or model of performance by a human operator. Each of these approaches is illustrated with data in the present review. Chronic ambient noise was found to have a significant but inconsequential effect on computer-task performance by rhesus monkeys (Macaca mulatta). Additional data supported the generality of findings such as these to humans, showing that rhesus monkeys are appropriate models of human psychomotor performance. It is argued that ultimately the interface between comparative psychology and technology will depend on the coordinated use of both strategies of investigation.

  14. Factors affecting performance of methyl bromide alternatives - a South Atlantic perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumigant application methods and equipment were identified as a source of variability in the performance of methyl bromide alternatives during several field demonstration trials conducted in 2007. Shank injection systems incorrectly modified to accommodate reduced fumigant flow rates through deliv...

  15. Pre-spawning parental stress affects channel catfish, Ictalurus punctatus reproduction and subsequent progeny performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Routine fish handling procedures associated with seining, selecting, transportation, crowding, weighing, and stripping have shown to cause negative physiological responses to hatchery performance. In teleosts, cortisol is the main corticosteroid released during stress, and hence, plasma cortisol co...

  16. Age and individual sleep characteristics affect cognitive performance in anesthesiology residents after a 24-hour shift.

    PubMed

    Tadinac, Meri; Sekulić, Ante; Hromatko, Ivana; Mazul-Sunko, Branka; Ivancić, Romina

    2014-03-01

    Previous research has shown that both shift work and sleep deprivation have an adverse influence on various aspects of human cognitive performance. The aim of this study was to explore changes in cognitive functioning and subjective sleepiness of anesthesiology residents after a 24-hour shift. Twenty-six anesthesiology residents completed a set of psychological instruments at the beginning and at the end of the shift, as well as a questionnaire regarding information about the shift, Stanford Sleepiness Scale, and Circadian Type Questionnaire. There was a significant decline in cognitive performance measured by the Auditory Verbal Learning Test after the shift. The effect was stronger in older participants and in those with high scores on rigidity of sleep scale and low scores on the ability to overcome sleepiness scale. There were no differences in the digits forward test (a measure of concentration), while digits backward test (a measure of working memory) even showed an improved performance after the shift. Although participants reported being significantly sleepier after the shift, the subjective sleepiness did not correlate with any of the objective measures of cognitive performance. In conclusion, the performance in short tasks involving concentration and working memory was not impaired, while performance in long-term and monotone tasks declined after sleep deprivation, and the magnitude of this decline depended on the specific individual characteristics of sleep and on age Surprisingly, age seemed to have an important impact on cognitive functions after shift work even in the relatively age-homogeneous population of young anesthesiology residents. PMID:24974663

  17. Affective Responses to Acute Resistance Exercise Performed at Self-Selected and Imposed Loads in Trained Women.

    PubMed

    Focht, Brian C; Garver, Matthew J; Cotter, Joshua A; Devor, Steven T; Lucas, Alexander R; Fairman, Ciaran M

    2015-11-01

    The purpose of this study was to examine the affective responses to acute resistance exercise (RE) performed at self-selected (SS) and imposed loads in recreationally trained women. Secondary purposes were to (a) examine differences in correlates of motivation for future participation in RE and (b) determine whether affective responses to RE were related to these select motivational correlates of RE participation. Twenty recreationally trained young women (mean age = 23 years) completed 3 RE sessions involving 3 sets of 10 repetitions using loads of 40% of 1 repetition maximum (1RM), 70% 1RM, and an SS load. Affective responses were assessed before, during, and after each RE session using the Feeling Scale. Self-efficacy and intention for using the imposed and SS loads for their regular RE participation during the next month were also assessed postexercise. Results revealed that although the SS and imposed load RE sessions yielded different trajectories of change in affect during exercise (p < 0.01), comparable improvements in affect emerged after RE. Additionally, the SS condition was associated with the highest ratings of self-efficacy and intention for future RE participation (p < 0.01), but affective responses to acute RE were unrelated to self-efficacy or intention. It is concluded that acute bouts of SS and imposed load RE resulted in comparable improvements in affect; recreationally trained women reported the highest self-efficacy and intention to use the load chosen in SS condition in their own resistance training; and affective responses were unrelated to motivational correlates of resistance training. PMID:26506060

  18. Structural factors affecting lithium transport in lithium-excess layered cathode materials

    NASA Astrophysics Data System (ADS)

    Fell, Christopher R.

    Lithium ion batteries have drawn significant attention as the principle energy storage device powering today's mobile electronic equipment. Despite the increased usage, the performance of current lithium ion battery technology falls short of the requirements needed for large format applications such as electric vehicles. The layered lithium-excess oxide compounds Li[NixLi1/3-2x/3Mn2/3-x/3]O2 are of interest as a new generation of cathode materials for high energy density lithium ion batteries. Efforts to achieve a better understanding of the electrochemistry of lithium-excess materials require the connection of crystal structure to electrochemical properties. In this dissertation, a combination of advanced characterization techniques was used as a tool to understand the intercalation mechanism of the layered lithium-excess transition metal oxide Li[NixLi1/3-2x/3Mn 2/3-x/3]O2. The research identified that synthesis influences the structure of the material specifically the surface of the particles. The formation of a hydroxide rich surface film decreases the electrochemical performance. Post synthesis modifications including high pressure and high temperature leads to the formation of a second layered phase in the bulk; however, the treated samples display good electrochemical properties. This result underlines the flexibility of the structure of Li[NixLi1/3-2x/3Mn 2/3-x/3]O2, a feature uncommon to other layered transition metal oxides. Surface characterization of the layered lithium-excess cathodes following electrochemical cycling revealed the formation of a new surface phase 1 to 5 nm thick as well as insight to the complex cation rearrangement process and phase transformation. This part of the research identified that significant changes occurred during electrochemical cycling; however did not identify when the transformations occurred. Investigation using in situ techniques during the first electrochemical cycle shows that the structure undergoes irreversible

  19. Linking geology and microbiology: inactive pockmarks affect sediment microbial community structure.

    PubMed

    Haverkamp, Thomas H A; Hammer, Øyvind; Jakobsen, Kjetill S

    2014-01-01

    Pockmarks are geological features that are found on the bottom of lakes and oceans all over the globe. Some are active, seeping oil or methane, while others are inactive. Active pockmarks are well studied since they harbor specialized microbial communities that proliferate on the seeping compounds. Such communities are not found in inactive pockmarks. Interestingly, inactive pockmarks are known to have different macrofaunal communities compared to the surrounding sediments. It is undetermined what the microbial composition of inactive pockmarks is and if it shows a similar pattern as the macrofauna. The Norwegian Oslofjord contains many inactive pockmarks and they are well suited to study the influence of these geological features on the microbial community in the sediment. Here we present a detailed analysis of the microbial communities found in three inactive pockmarks and two control samples at two core depth intervals. The communities were analyzed using high-throughput amplicon sequencing of the 16S rRNA V3 region. Microbial communities of surface pockmark sediments were indistinguishable from communities found in the surrounding seabed. In contrast, pockmark communities at 40 cm sediment depth had a significantly different community structure from normal sediments at the same depth. Statistical analysis of chemical variables indicated significant differences in the concentrations of total carbon and non-particulate organic carbon between 40 cm pockmarks and reference sample sediments. We discuss these results in comparison with the taxonomic classification of the OTUs identified in our samples. Our results indicate that microbial communities at the sediment surface are affected by the water column, while the deeper (40 cm) sediment communities are affected by local conditions within the sediment. PMID:24475066

  20. Steroidal aromatic 'naphthenic acids' in oil sands process-affected water: structural comparisons with environmental estrogens.

    PubMed

    Rowland, Steven J; West, Charles E; Jones, David; Scarlett, Alan G; Frank, Richard A; Hewitt, L Mark

    2011-11-15

    The large volumes, acute toxicity, estrogenicity, and antiandrogenicity of process-affected waters accruing in tailings ponds from the operations of the Alberta oil sands industries pose a significant task for environmental reclamation. Synchronous fluorescence spectra (SFS) suggest that oil sands process-affected water (OSPW) may contain aromatic carboxylic acids, which are among the potentially environmentally important toxicants, but no such acids have yet been identified, limiting interpretations of the results of estrogenicity and other assays. Here we show that multidimensional comprehensive gas chromatography-mass spectrometry (GCxGC-MS) of methyl esters of acids in an OSPW sample produces mass spectra consistent with their assignment as C(19) and C(20) C-ring monoaromatic hydroxy steroid acids, D-ring opened hydroxy and nonhydroxy polyhydrophenanthroic acids with one aromatic and two alicyclic rings and A-ring opened steroidal keto acids. High resolution MS data support the assignment of several of the so-called 'O3' species. When fractions of distilled, esterified, OSPW acid-extractable organics were examined, the putative aromatics were mainly present in a high boiling fraction; when examined by argentation thin layer chromatography, some were present in a fraction with a retardation factor between that of the methyl esters of synthetic monoalicyclic and monoaromatic acids. Ultraviolet absorption spectra of these fractions indicated the presence of benzenoid moieties. SFS of model octahydro- and tetrahydrophenanthroic acids produced emissions at the characteristic excitation wavelengths observed in some OSPW extracts, consistent with the postulations from ultraviolet spectroscopy and mass spectrometry data. We suggest the acids originate from extensive biodegradation of C-ring monoaromatic steroid hydrocarbons and offer a means of differentiating residues at different biodegradation stages in tailings ponds. Structural similarities with estrone and

  1. Earthworm-Mycorrhiza Interactions Can Affect the Diversity, Structure and Functioning of Establishing Model Grassland Communities

    PubMed Central

    Zaller, Johann G.; Heigl, Florian; Grabmaier, Andrea; Lichtenegger, Claudia; Piller, Katja; Allabashi, Roza; Frank, Thomas; Drapela, Thomas

    2011-01-01

    Both earthworms and arbuscular mycorrhizal fungi (AMF) are important ecosystem engineers co-occurring in temperate grasslands. However, their combined impacts during grassland establishment are poorly understood and have never been studied. We used large mesocosms to study the effects of different functional groups of earthworms (i.e., vertically burrowing anecics vs. horizontally burrowing endogeics) and a mix of four AMF taxa on the establishment, diversity and productivity of plant communities after a simulated seed rain of 18 grassland species comprising grasses, non-leguminous forbs and legumes. Moreover, effects of earthworms and/or AMF on water infiltration and leaching of ammonium, nitrate and phosphate were determined after a simulated extreme rainfall event (40 l m−2). AMF colonisation of all three plant functional groups was altered by earthworms. Seedling emergence and diversity was reduced by anecic earthworms, however only when AMF were present. Plant density was decreased in AMF-free mesocosms when both anecic and endogeic earthworms were active; with AMF also anecics reduced plant density. Plant shoot and root biomass was only affected by earthworms in AMF-free mesocosms: shoot biomass increased due to the activity of either anecics or endogeics; root biomass increased only when anecics were active. Water infiltration increased when earthworms were present in the mesocosms but remained unaffected by AMF. Ammonium leaching was increased only when anecics or a mixed earthworm community was active but was unaffected by AMF; nitrate and phosphate leaching was neither affected by earthworms nor AMF. Ammonium leaching decreased with increasing plant density, nitrate leaching decreased with increasing plant diversity and density. In order to understand the underlying processes of these interactions further investigations possibly under field conditions using more diverse belowground communities are required. Nevertheless, this study demonstrates that

  2. Linking Geology and Microbiology: Inactive Pockmarks Affect Sediment Microbial Community Structure

    PubMed Central

    Haverkamp, Thomas H. A.; Hammer, Øyvind; Jakobsen, Kjetill S.

    2014-01-01

    Pockmarks are geological features that are found on the bottom of lakes and oceans all over the globe. Some are active, seeping oil or methane, while others are inactive. Active pockmarks are well studied since they harbor specialized microbial communities that proliferate on the seeping compounds. Such communities are not found in inactive pockmarks. Interestingly, inactive pockmarks are known to have different macrofaunal communities compared to the surrounding sediments. It is undetermined what the microbial composition of inactive pockmarks is and if it shows a similar pattern as the macrofauna. The Norwegian Oslofjord contains many inactive pockmarks and they are well suited to study the influence of these geological features on the microbial community in the sediment. Here we present a detailed analysis of the microbial communities found in three inactive pockmarks and two control samples at two core depth intervals. The communities were analyzed using high-throughput amplicon sequencing of the 16S rRNA V3 region. Microbial communities of surface pockmark sediments were indistinguishable from communities found in the surrounding seabed. In contrast, pockmark communities at 40 cm sediment depth had a significantly different community structure from normal sediments at the same depth. Statistical analysis of chemical variables indicated significant differences in the concentrations of total carbon and non-particulate organic carbon between 40 cm pockmarks and reference sample sediments. We discuss these results in comparison with the taxonomic classification of the OTUs identified in our samples. Our results indicate that microbial communities at the sediment surface are affected by the water column, while the deeper (40 cm) sediment communities are affected by local conditions within the sediment. PMID:24475066

  3. Parameters affecting resin-anchored cable bolt performance: Results of in situ evaluations

    SciTech Connect

    Zelanko, J.C.; Mucho, T.P.; Compton, C.S.; Long, L.E.; Bailey, P.E.

    1995-11-01

    Cable bolt support techniques, including hardware and anchorage systems, continue to evolve to meet US mining requirements. For cable support systems to be successfully implemented into new ground control areas, the mechanics of this support and the potential range of performance need to be better understood. To contribute to this understanding, a series of 36 pull tests were performed on 10 ft long cable bolts using various combinations of hole diameters, resin formulations, anchor types, and with and without resin dams. These test provided insight as to the influence of these four parameters on cable system performance. Performance was assessed in terms of support capacity (maximum load attained in a pull test), system stiffness (assessed from two intervals of load-deformation), and from the general load-deformation response. Three characteristic load-deformation responses were observed. An Analysis of Variance identified a number of main effects and interactions of significance to support capacity and stiffness. The factorial experiment performed in this study provides insight to the effects of several design parameters associated with resin-anchored cable bolts.

  4. Unilateral hemispherectomy at adulthood asymmetrically affects motor performance of male Swiss mice.

    PubMed

    Paes-Branco, Danielle; Abreu-Villaça, Yael; Manhães, Alex C; Filgueiras, Cláudio C

    2012-05-01

    Evidence exists indicating that cerebral lateralization is a fundamental feature of all vertebrates. In humans, a series of studies demonstrated that the left hemisphere plays a major role in controlling movement. No such asymmetries have been identified in rodents, in spite of the fact that these animals have been frequently used in studies assessing motor behavior. In this regard, here, we used unilateral hemispherectomy to study the relative importance of each hemisphere in controlling movement. Adult Swiss mice were submitted to right unilateral hemispherectomy (RH), left unilateral hemispherectomy (LH) or sham surgery. Fifteen days after surgery, motor performance was assessed in the accelerating rotarod test and in the foot-fault test (in which performance depends on skilled limb use) and in the elevated body swing test (in which performance depends on trunk movements). The surgical removal of the right hemisphere caused a more pronounced impairment in performance than the removal of the left hemisphere both in the rotarod and in the foot-fault tests. In the rotarod, the RH group presented smaller latencies to fall than both LH and sham groups. In the foot-fault test, while both the sham and the LH groups showed no differences between left and right hind limbs, the RH group showed significantly worse performance with the left hind limb than with the right one. The elevated body swing test revealed a similar impairment in the two hemispherectomized groups. Our data suggest a major role of the right hemisphere in controlling skilled limb movements in mice. PMID:22367398

  5. Design of an embedded sensor, for improved structural performance

    NASA Astrophysics Data System (ADS)

    Chilles, James S.; Croxford, Anthony; Bond, Ian P.

    2015-11-01

    Low velocity impact damage to composite laminates can result in a complicated network of matrix cracks and delaminations beneath the laminates surface, which are extremely difficult to detect by visual inspection. Current non-destructive evaluation (NDE) techniques such as ultrasonic C-scan and x-ray imaging create significant downtime, which leads to costly inspection programmes. Embedded sensors offer the potential to increase the automation of inspection, and decrease the downtime when compared with current NDE practices. However, for such systems to be practical, sensors must be integrated within composite structures without producing unacceptable loss of structural performance. This paper identifies techniques for embedding slim sensors with comparatively large in-plane dimensions inside composite materials. Interlaminar shear strength tests were used to identify an encapsulating layer for the sensors. Flexural strength testing was carried out on laminates containing sensors embedded towards the compressive surface of flexural specimens. The experimental study was complemented with finite element analysis, which identified the load paths within different embedment configurations and aided with the interpretation of the experimental results. The results show that with careful selection of sensor materials, geometry, embedding location and embedment technique, sensors can be integrated within composite structures without producing any significant reduction of mechanical performance.

  6. Buried structure for increasing fabrication performance of micromaterial by electromigration

    NASA Astrophysics Data System (ADS)

    Kimura, Yasuhiro; Saka, Masumi

    2016-06-01

    The electromigration (EM) technique is a physical synthetic growth method for micro/nanomaterials. EM causes atomic diffusion in a metal line by high-density electron flows. The intentional control of accumulation and relaxation of atoms by EM can lead to the fabrication of a micro/nanomaterial. TiN passivation has been utilized as a component of sample in the EM technique. Although TiN passivation can simplify the cumbersome processes for preparing the sample, the leakage of current naturally occurs because of the conductivity of TiN as a side effect and decreases the performance of micro/nanomaterial fabrication. In the present work, we propose a buried structure, which contributes to significantly decreasing the current for fabricating an Al micromaterial by confining the current flow in the EM technique. The fabrication performance was evaluated based on the threshold current for fabricating an Al micromaterial using the buried structure and the previous structure with the leakage of current.

  7. The structure of performance of a sport rock climber.

    PubMed

    Magiera, Artur; Roczniok, Robert; Maszczyk, Adam; Czuba, Miłosz; Kantyka, Joanna; Kurek, Piotr

    2013-03-01

    This study is a contribution to the discussion about the structure of performance of sport rock climbers. Because of the complex and multifaceted nature of this sport, multivariate statistics were applied in the study. The subjects included thirty experienced sport climbers. Forty three variables were scrutinised, namely somatic characteristics, specific physical fitness, coordination abilities, aerobic and anaerobic power, technical and tactical skills, mental characteristics, as well as 2 variables describing the climber's performance in the OS (Max OS) and RP style (Max RP). The results show that for training effectiveness of advanced climbers to be thoroughly analysed and examined, tests assessing their physical, technical and mental characteristics are necessary. The three sets of variables used in this study explained the structure of performance similarly, but not identically (in 38, 33 and 25%, respectively). They were also complementary to around 30% of the variance. The overall performance capacity of a sport rock climber (Max OS and Max RP) was also evaluated in the study. The canonical weights of the dominant first canonical root were 0.554 and 0.512 for Max OS and Max RP, respectively. Despite the differences between the two styles of climbing, seven variables - the maximal relative strength of the fingers (canonical weight = 0.490), mental endurance (one of scales : The Formal Characteristics of Behaviour-Temperament Inventory (FCB-TI; Strelau and Zawadzki, 1995)) (-0.410), climbing technique (0.370), isometric endurance of the fingers (0.340), the number of errors in the complex reaction time test (-0.319), the ape index (-0.319) and oxygen uptake during arm work at the anaerobic threshold (0.254) were found to explain 77% of performance capacity common to the two styles. PMID:23717360

  8. Thought waves remotely affect the performance (output voltage) of photoelectric cells

    NASA Astrophysics Data System (ADS)

    Cao, Dayong; Cao, Daqing

    2012-02-01

    In our experiments, thought waves have been shown to be capable of changing (affecting) the output voltage of photovoltaic cells located from as far away as 1-3 meters. There are no wires between brain and photoelectric cell and so it is presumed only the thought waves act on the photoelectric cell. In continual rotations, the experiments tested different solar cells, measuring devices and lamps, and the experiments were done in different labs. The first experiment was conducted on Oct 2002. Tests are ongoing. Conclusions and assumptions include: 1) the slow thought wave has the energy of space-time as defined by C1.00007: The mass, energy, space and time systemic theory- MEST. Every process releases a field effect electrical vibration which be transmitted and focussed in particular paths; 2) the thought wave has the information of the order of tester; 3) the brain (with the physical system of MEST) and consciousness (with the spirit system of the mind, consciousness, emotion and desire-MECD) can produce the information (a part of them as the Genetic code); 4) through some algorithms such as ACO Ant Colony Optimization and EA Evolutionary Algorithm (or genetic algorithm) working in RAM, human can optimize the information. This Optimizational function is the intelligence; 5) In our experiments, not only can thought waves affect the voltage of the output photoelectric signals by its energy, but they can also selectively increase or decrease those photoelectric currents through remote consciousness interface and a conscious-brain information technology.

  9. Abdominally implanted transmitters with percutaneous antennas affect the dive performance of Common Eiders

    USGS Publications Warehouse

    Powell, Abby N.; Latty, Christopher J.; Hollmén, Tuula E.; Petersen, Margaret R.; Andrews, Russel D.

    2010-01-01

    Implanted transmitters have become an important tool for studying the ecology of sea ducks, but their effects remain largely undocumented. To address this, we assessed how abdominally implanted transmitters with percutaneous antennas affect the vertical dive speeds, stroke frequencies, bottom time, and dive duration of captive Common Eiders (Somateria mollissima). To establish baselines, we recorded video of six birds diving 4.9 m prior to surgery, implanted them with 38- to 47-g platform transmitter terminals, and then recorded their diving for 3.5 months after surgery to determine effects. Descent speeds were 16–25% slower and ascent speeds were 17–44% slower after surgery, and both remained below baseline at the end of the study. Dive durations were longer than baseline until day 22. On most days between 15 and 107 days after surgery, foot-stroke frequencies of birds foraging on the bottom were slower. Foot- and wing-stroke frequencies during descent and bottom time did not differ across the time series. If birds that rely on benthic invertebrates for sustenance dive slower and stay submerged longer after being implanted with a satellite transmitter, their foraging energetics may be affected. Researchers considering use of implanted transmitters with percutaneous antennas should be mindful of these effects and the possibility of concomitant alterations in diving behavior, foraging success, and migratory behavior compared to those of unmarked conspecifics.

  10. Power affects performance when the pressure is on: evidence for low-power threat and high-power lift.

    PubMed

    Kang, Sonia K; Galinsky, Adam D; Kray, Laura J; Shirako, Aiwa

    2015-05-01

    The current research examines how power affects performance in pressure-filled contexts. We present low-power-threat and high-power-lift effects, whereby performance in high-stakes situations suffers or is enhanced depending on one's power; that is, the power inherent to a situational role can produce effects similar to stereotype threat and lift. Three negotiations experiments demonstrate that role-based power affects outcomes but only when the negotiation is diagnostic of ability and, therefore, pressure-filled. We link these outcomes conceptually to threat and lift effects by showing that (a) role power affects performance more strongly when the negotiation is diagnostic of ability and (b) underperformance disappears when the low-power negotiator has an opportunity to self-affirm. These results suggest that stereotype threat and lift effects may represent a more general phenomenon: When the stakes are raised high, relative power can act as either a toxic brew (stereotype/low-power threat) or a beneficial elixir (stereotype/high-power lift) for performance. PMID:25888684

  11. Starch Granule Re-Structuring by Starch Branching Enzyme and Glucan Water Dikinase Modulation Affects Caryopsis Physiology and Metabolism.

    PubMed

    Shaik, Shahnoor S; Obata, Toshihiro; Hebelstrup, Kim H; Schwahn, Kevin; Fernie, Alisdair R; Mateiu, Ramona V; Blennow, Andreas

    2016-01-01

    Starch is of fundamental importance for plant development and reproduction and its optimized molecular assembly is potentially necessary for correct starch metabolism. Re-structuring of starch granules in-planta can therefore potentially affect plant metabolism. Modulation of granule micro-structure was achieved by decreasing starch branching and increasing starch-bound phosphate content in the barley caryopsis starch by RNAi suppression of all three Starch Branching Enzyme (SBE) isoforms or overexpression of potato Glucan Water Dikinase (GWD). The resulting lines displayed Amylose-Only (AO) and Hyper-Phosphorylated (HP) starch chemotypes, respectively. We studied the influence of these alterations on primary metabolism, grain composition, starch structural features and starch granule morphology over caryopsis development at 10, 20 and 30 days after pollination (DAP) and at grain maturity. While HP showed relatively little effect, AO showed significant reduction in starch accumulation with re-direction to protein and β-glucan (BG) accumulation. Metabolite profiling indicated significantly higher sugar accumulation in AO, with re-partitioning of carbon to accumulate amino acids, and interestingly it also had high levels of some important stress-related metabolites and potentially protective metabolites, possibly to elude deleterious effects. Investigations on starch molecular structure revealed significant increase in starch phosphate and amylose content in HP and AO respectively with obvious differences in starch granule morphology at maturity. The results demonstrate that decreasing the storage starch branching resulted in metabolic adjustments and re-directions, tuning to evade deleterious effects on caryopsis physiology and plant performance while only little effect was evident by increasing starch-bound phosphate as a result of overexpressing GWD. PMID:26891365

  12. Starch Granule Re-Structuring by Starch Branching Enzyme and Glucan Water Dikinase Modulation Affects Caryopsis Physiology and Metabolism

    PubMed Central

    Shaik, Shahnoor S.; Obata, Toshihiro; Hebelstrup, Kim H.; Schwahn, Kevin; Fernie, Alisdair R.; Mateiu, Ramona V.; Blennow, Andreas

    2016-01-01

    Starch is of fundamental importance for plant development and reproduction and its optimized molecular assembly is potentially necessary for correct starch metabolism. Re-structuring of starch granules in-planta can therefore potentially affect plant metabolism. Modulation of granule micro-structure was achieved by decreasing starch branching and increasing starch-bound phosphate content in the barley caryopsis starch by RNAi suppression of all three Starch Branching Enzyme (SBE) isoforms or overexpression of potato Glucan Water Dikinase (GWD). The resulting lines displayed Amylose-Only (AO) and Hyper-Phosphorylated (HP) starch chemotypes, respectively. We studied the influence of these alterations on primary metabolism, grain composition, starch structural features and starch granule morphology over caryopsis development at 10, 20 and 30 days after pollination (DAP) and at grain maturity. While HP showed relatively little effect, AO showed significant reduction in starch accumulation with re-direction to protein and β-glucan (BG) accumulation. Metabolite profiling indicated significantly higher sugar accumulation in AO, with re-partitioning of carbon to accumulate amino acids, and interestingly it also had high levels of some important stress-related metabolites and potentially protective metabolites, possibly to elude deleterious effects. Investigations on starch molecular structure revealed significant increase in starch phosphate and amylose content in HP and AO respectively with obvious differences in starch granule morphology at maturity. The results demonstrate that decreasing the storage starch branching resulted in metabolic adjustments and re-directions, tuning to evade deleterious effects on caryopsis physiology and plant performance while only little effect was evident by increasing starch-bound phosphate as a result of overexpressing GWD. PMID:26891365

  13. Performance Trend of Different Algorithms for Structural Design Optimization

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Coroneos, Rula M.; Guptill, James D.; Hopkins, Dale A.

    1996-01-01

    Nonlinear programming algorithms play an important role in structural design optimization. Fortunately, several algorithms with computer codes are available. At NASA Lewis Research Center, a project was initiated to assess performance of different optimizers through the development of a computer code CometBoards. This paper summarizes the conclusions of that research. CometBoards was employed to solve sets of small, medium and large structural problems, using different optimizers on a Cray-YMP8E/8128 computer. The reliability and efficiency of the optimizers were determined from the performance of these problems. For small problems, the performance of most of the optimizers could be considered adequate. For large problems however, three optimizers (two sequential quadratic programming routines, DNCONG of IMSL and SQP of IDESIGN, along with the sequential unconstrained minimizations technique SUMT) outperformed others. At optimum, most optimizers captured an identical number of active displacement and frequency constraints but the number of active stress constraints differed among the optimizers. This discrepancy can be attributed to singularity conditions in the optimization and the alleviation of this discrepancy can improve the efficiency of optimizers.

  14. Factors affecting altitude relight performance of a double-annular ram-induction combustor

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.; Mularz, E. J.

    1972-01-01

    A test program was conducted to evaluate the altitude relight capabilities of a short-length, double-annular, ram-induction combustor which was designed for Mach 3 cruise operation. The use of distorted inlet-air flow profiles was tried to evaluate their effect on the relight performance. No significant improvement in altitude relight performance was obtained with this approach. A study was also made to determine the effects of the reference Mach number, the fuel temperature, and the fuel volatility (ASTM-A1 against JP-4) on the altitude relight performance. Decreasing the reference Mach number, increasing the fuel temperature, and using more volatile fuel all decrease the combustor pressure necessary for relight.

  15. Does training frequency and supervision affect compliance, performance and muscular health? A cluster randomized controlled trial.

    PubMed

    Dalager, Tina; Bredahl, Thomas G V; Pedersen, Mogens T; Boyle, Eleanor; Andersen, Lars L; Sjøgaard, Gisela

    2015-10-01

    The aim was to determine the effect of one weekly hour of specific strength training within working hours, performed with the same total training volume but with different training frequencies and durations, or with different levels of supervision, on compliance, muscle health and performance, behavior and work performance. In total, 573 office workers were cluster-randomized to: 1 WS: one 60-min supervised session/week, 3 WS: three 20-min supervised sessions/week, 9 WS: nine 7-min supervised sessions/week, 3 MS: three 20-min sessions/week with minimal supervision, or REF: a reference group without training. Outcomes were diary-based compliance, total training volume, muscle performance and questionnaire-based health, behavior and work performance. Comparisons were made among the WS training groups and between 3 WS and 3 MS. If no difference, training groups were collapsed (TG) and compared with REF. Results demonstrated similar degrees of compliance, mean(range) of 39(33-44)%, and total training volume, 13.266(11.977-15.096)kg. Musculoskeletal pain in neck and shoulders were reduced with approx. 50% in TG, which was significant compared with REF. Only the training groups improved significantly their muscle strength 8(4-13)% and endurance 27(12-37)%, both being significant compared with REF. No change in workability, productivity or self-rated health was demonstrated. Secondary analysis showed exercise self-efficacy to be a significant predictor of compliance. Regardless of training schedule and supervision, similar degrees of compliance were shown together with reduced musculoskeletal pain and improved muscle performance. These findings provide evidence that a great degree of flexibility is legitimate for companies in planning future implementation of physical exercise programs at the workplace. ClinicalTrials.gov, number NCT01027390. PMID:25816746

  16. Trichobaris weevils distinguish amongst toxic host plants by sensing volatiles that do not affect larval performance.

    PubMed

    Lee, Gisuk; Joo, Youngsung; Diezel, Celia; Lee, Eun Ju; Baldwin, Ian T; Kim, Sang-Gyu

    2016-07-01

    Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host-selection behaviours are often consistent with the preference-performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically relevant interactions. Here, we examined the host-selection behaviours of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field and glasshouse experiments with transgenic host plants specifically altered in different components of their secondary metabolism. Adult females of both species strongly preferred to feed on D. wrightii rather than on N. attenuata leaves, but T. mucorea preferred to oviposit on N. attenuata, while T. compacta oviposited only on D. wrightii. These oviposition behaviours increased offspring performance: T. compacta larvae only survived in D. wrightii stems and T. mucorea larvae survived better in N. attenuata than in D. wrightii stems. Choice assays with nicotine-free, JA-impaired, and sesquiterpene-over-produced isogenic N. attenuata plants revealed that although half of the T. compacta larvae survived in nicotine-free N. attenuata lines, nicotine did not influence the oviposition behaviours of both the nicotine-adapted and nicotine-sensitive species. JA-induced sesquiterpene volatiles are key compounds influencing T. mucorea females' oviposition choices, but these sesquiterpenes had no effect on larval performance. We conclude that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions. PMID:27146082

  17. Maternal aging affects life performance of progeny in a Holstein dairy cow model.

    PubMed

    Astiz, S; Gonzalez-Bulnes, A; Sebastian, F; Fargas, O; Cano, I; Cuesta, P

    2014-10-01

    The development and life performance of 404 high-producing Holstein dairy cows was studied from birth onwards and during two lactations. The management, environment and parental genetics of the cows were known in detail. Cluster analysis identified four performance 'types': high-yielding (HY) cows and persistently high-yielding (PHY) cows, which accounted for 33% of the animals; medium-yielding (MY) cows, 41%; and low-yielding (LY) cows, 26%. Prenatal determinants of the life performance of the progeny were analyzed. Developmental and environmental factors were excluded as determinants of performance (including birth weight, level of passive immunity transfer, growth rate, age at first parturition and reproductive efficiency). Life performance did show minor seasonal effects, with more HY cows but less PHY being born during the cold season (90.1% in HY; 58.3% in PHY v. 81.5%). Instead, the single most important factor influencing life performance of daughters was maternal age. HY cows were born from the youngest mothers (1.89±1.14 parturitions, 3.12±1.42-year old), whereas LY cows were born from the oldest (2.72±1.80 parturitions, 3.97±2.01-year old; P<0.001). Life performance of the dams did not differ among clusters. In addition, metabolic parameters (fat and protein yield) were found to correlate significantly with yields between the first and second lactations (milk yield: r=0.357; fat yield: r=0.211; protein yield: r=0.277; P<0.0001), suggesting the influence of the individual. These results suggest that under optimal health, nutritional and environmental conditions, maternal aging is an important determinant of the life performance of progeny and argue for the need to identify conditions that contribute to health and disease in progeny according to the Developmental Origin of Health and Disease or DOHaD concept. Our findings may help the development of novel management guidelines for dairy farms. PMID:25084160

  18. Ketogenic diet does not affect strength performance in elite artistic gymnasts

    PubMed Central

    2012-01-01

    Background Despite the increasing use of very low carbohydrate ketogenic diets (VLCKD) in weight control and management of the metabolic syndrome there is a paucity of research about effects of VLCKD on sport performance. Ketogenic diets may be useful in sports that include weight class divisions and the aim of our study was to investigate the influence of VLCKD on explosive strength performance. Methods 8 athletes, elite artistic gymnasts (age 20.9 ± 5.5 yrs) were recruited. We analyzed body composition and various performance aspects (hanging straight leg raise, ground push up, parallel bar dips, pull up, squat jump, countermovement jump, 30 sec continuous jumps) before and after 30 days of a modified ketogenic diet. The diet was based on green vegetables, olive oil, fish and meat plus dishes composed of high quality protein and virtually zero carbohydrates, but which mimicked their taste, with the addition of some herbal extracts. During the VLCKD the athletes performed the normal training program. After three months the same protocol, tests were performed before and after 30 days of the athletes’ usual diet (a typically western diet, WD). A one-way Anova for repeated measurements was used. Results No significant differences were detected between VLCKD and WD in all strength tests. Significant differences were found in body weight and body composition: after VLCKD there was a decrease in body weight (from 69.6 ± 7.3 Kg to 68.0 ± 7.5 Kg) and fat mass (from 5.3 ± 1.3 Kg to 3.4 ± 0.8 Kg p < 0.001) with a non-significant increase in muscle mass. Conclusions Despite concerns of coaches and doctors about the possible detrimental effects of low carbohydrate diets on athletic performance and the well known importance of carbohydrates there are no data about VLCKD and strength performance. The undeniable and sudden effect of VLCKD on fat loss may be useful for those athletes who compete in sports based on weight class. We have

  19. CFH Variants Affect Structural and Functional Brain Changes and Genetic Risk of Alzheimer's Disease.

    PubMed

    Zhang, Deng-Feng; Li, Jin; Wu, Huan; Cui, Yue; Bi, Rui; Zhou, He-Jiang; Wang, Hui-Zhen; Zhang, Chen; Wang, Dong; Kong, Qing-Peng; Li, Tao; Fang, Yiru; Jiang, Tianzi; Yao, Yong-Gang

    2016-03-01

    The immune response is highly active in Alzheimer's disease (AD). Identification of genetic risk contributed by immune genes to AD may provide essential insight for the prognosis, diagnosis, and treatment of this neurodegenerative disease. In this study, we performed a genetic screening for AD-related top immune genes identified in Europeans in a Chinese cohort, followed by a multiple-stage study focusing on Complement Factor H (CFH) gene. Effects of the risk SNPs on AD-related neuroimaging endophenotypes were evaluated through magnetic resonance imaging scan, and the effects on AD cerebrospinal fluid biomarkers (CSF) and CFH expression changes were measured in aged and AD brain tissues and AD cellular models. Our results showed that the AD-associated top immune genes reported in Europeans (CR1, CD33, CLU, and TREML2) have weak effects in Chinese, whereas CFH showed strong effects. In particular, rs1061170 (P(meta)=5.0 × 10(-4)) and rs800292 (P(meta)=1.3 × 10(-5)) showed robust associations with AD, which were confirmed in multiple world-wide sample sets (4317 cases and 16 795 controls). Rs1061170 (P=2.5 × 10(-3)) and rs800292 (P=4.7 × 10(-4)) risk-allele carriers have an increased entorhinal thickness in their young age and a higher atrophy rate as the disease progresses. Rs800292 risk-allele carriers have higher CSF tau and Aβ levels and severe cognitive decline. CFH expression level, which was affected by the risk-alleles, was increased in AD brains and cellular models. These comprehensive analyses suggested that CFH is an important immune factor in AD and affects multiple pathological changes in early life and during disease progress. PMID:26243271

  20. Factors affecting performance on a target monitoring task employing an automatic tracker.

    PubMed

    McFadden, Sharon M; Vimalachandran, Abhirami; Blackmore, Elizabeth

    2004-02-26

    The experiments in this paper examined the extent to which performance on a task employing an automatic tracker was similar to performance on tasks employing other types of automation that have been studied more extensively. Automated target tracking is being used in many sensor and navigation systems to improve performance and help the operator cope with increased data loads. With many automated systems these goals are not met. In particular, the operator often misses errors made by the automated system and may report no decrease in workload. Several hypotheses have been offered for the operator's failure to monitor an automated system adequately. These include lack of experience with the manual task, a vigilance decrement, complacency, and inappropriate level of automation. The relevance of each of these hypotheses to failure to monitor an automatic tracker adequately was examined. Performance and perceived workload on a target tracking task employing an automatic tracker, in which participants had to detect and then update the position of several targets (e.g. ships) at regular intervals, were measured as a function of number of targets, training with the manual task, experience, and time on task. The results suggested that failure to detect errors made by the automated system was due largely to the lack of visibility of the automation errors relative to other errors. However, complacency could not be ruled out entirely. Unlike some other tasks, the availability of a reliable automatic tracker did lead to a substantial reduction in perceived workload. PMID:14668161

  1. Does Topic Familiarity Affect Assessed Difficulty and Actual Performance on Reading Comprehension Tests in LSP?

    ERIC Educational Resources Information Center

    Peretz, Arna S.; Shoham, Miriam

    A study investigated the hypothesis that topic familiarity and assessed difficulty of a second language text correlated positively with performance on reading comprehension tests in languages for special purposes (LSP). Subjects were 177 advanced students of English as a Foreign Language (EFL) at Ben Gurion University (Israel). Faculty from the…

  2. Testing Reading Comprehension in LSP: Does Topic Familiarity Affect Assessed Difficulty and Actual Performance?

    ERIC Educational Resources Information Center

    Peretz, Arna S.; Shoham, Miriam

    1990-01-01

    Investigates hypothesis that topic familiarity and assessed difficulty of a text correlate positively with performance on reading comprehension tests. A study of 177 advanced students of English for Specific Purposes indicates that students' subjective evaluation of the relative difficulty of a reading text is not always a reliable index of their…

  3. The Use of Contingency Management to Affect Learning Performance in Adult Institutionalized Offenders.

    ERIC Educational Resources Information Center

    McKee, John M.

    A description is given of the development and application of contingency management (CM) techniques to the educational performance of a broad cross section of adult, male prison inmates. By most standards, these inmates are judged to be at the lowest rung of the motivational ladder. Draper Correctional Center experimental and demonstration…

  4. Does Posting PowerPoint Presentations on WebCT Affect Class Performance or Attendance?

    ERIC Educational Resources Information Center

    Bowman, Laura L.

    2009-01-01

    Grade earned and class attendance records were examined to determine if posting PowerPoint notes on a web-based course management system was related to enhanced performance or increased absences. There were no differences in either grades or absences between classes that had notes posted and those that did not. However, results indicated…

  5. The order of concurrent training does not affect soccer-related performance adaptations.

    PubMed

    McGawley, K; Andersson, P-I

    2013-11-01

    Despite the wealth of evidence regarding physical training strategies in soccer, there is little information regarding soccer-specific concurrent training and the effects of training order. The current study aimed to: i) quantify the effects of concurrent high-intensity run-based training (HIT) and strength- and power-based training (STR) on soccer-specific performance, and ii) investigate the order effect of completing HIT and STR either first or second within training sessions. Eighteen semi- and fully-professional players completed a battery of field- and gym-based tests before and after a 5-week pre-season training intervention. Players were pair-matched and completed 3 sessions per week of HIT followed by STR (n=9) or STR followed by HIT (n=9). ANCOVA tests revealed no differences between groups for changes in any of the measures (p>0.05). However, a training effect was observed for all measures (p<0.05), with 10-m sprint, 6×30-m repeated sprint, 40-m agility and Yo-Yo test performances improving by 1.8±2.6%, 1.3±1.8%, 1.0±1.5% and 19.4±23.4%, respectively (n=18). In conclusion, there was a positive effect of the concurrent training approach on key measures of soccer performance, but the order of completing HIT and STR appears inconsequential to performance adaptations. PMID:23700329

  6. Learning in the Laboratory: How Group Assignments Affect Motivation and Performance

    ERIC Educational Resources Information Center

    Belanger, John R.

    2016-01-01

    Team projects can optimize educational resources in a laboratory, but also create the potential for social loafing. Allowing students to choose their own groups could increase their motivation to learn and improve academic performance. To test this hypothesis, final grades and feedback from students were compared for the same course in two…

  7. Variables Affecting the Performance of ESOL/Bilingual Students in Non-ESOL Classes.

    ERIC Educational Resources Information Center

    Gross, Susan

    The Montgomery County (Maryland) Public School system is currently in its second year of a multiyear evaluation of the ESOL/bilingual program. The focus of the first year's effort was an analysis of test results and teacher evaluations of the overall classroom performance of over 3,000 students receiving ESOL/bilingual services. Findings were as…

  8. Do Learning and Study Skills Affect Academic Performance?--An Empirical Investigation

    ERIC Educational Resources Information Center

    Griffin, Richard; MacKewn, Angie; Moser, Ernest; VanVuren, Ken W.

    2012-01-01

    Universities and colleges are very interested in understanding the factors that influence their students' academic performance. This paper describes a study that was conducted at a mid-sized public university in the mid-south, USA, to examine this issue. In this study, the 10-scale, Learning and Study Strategies Inventory (LASSI) (Weinstein et…

  9. Aural Dictation Affects High Achievement in Sight Singing, Performance and Composition Skills

    ERIC Educational Resources Information Center

    Rogers, Melissa

    2013-01-01

    The nature of skill acquisition has long been of interest to music educators. This study considers the research context for relationships between aural dictation, sight singing, performance and composition skills. Then, relationships between these skill areas are quantitatively investigated using data from the Australian New South Wales Music 2…

  10. Entrance Qualifications Affect the Performance of Nutrition Students at University: A Pilot Study

    ERIC Educational Resources Information Center

    Owusu-Apenten, Richard; Xu, Wen Li

    2012-01-01

    This study assessed the effect of admissions qualifications on the subsequent academic performances of BSc nutrition students at a UK university. Entrance qualifications for three groups (Grp01, Grp02, Grp03) reading for a BSc(Hons) degree in, Dietetics, Food & Nutrition or Human Nutrition (n = 105) were determined from their UCAS (Universities…

  11. GEOCHEMICAL AND MICROBIAL REACTIONS AFFECTING THE LONG-TERM PERFORMANCE OF IN SITU 'IRON BARRIERS'

    EPA Science Inventory

    The in situ application of granular iron (Fe0) has become popular for the destruction of halogenated organic compounds for the immobilization of specific metals in groundwater. However, a knowledge gap exists concerning the long-term performance of the Fe0-barriers. The corrosi...

  12. FACTORS AFFECTING THE HYDRAULIC BARRIER PERFORMANCE OF SOIL-BENTONITE MIXTURE CUT-OFF WALL

    NASA Astrophysics Data System (ADS)

    Takai, Atsushi; Inui, Toru; Katsumi, Takeshi; Kamon, Masashi; Araki, Susumu

    Containment technique using cut-off walls is a valid method against contaminants in subsurface soil and/or groundwater. This paper states laboratory testing results on hydraulic barrier performance of Soil-Bentonite (SB), which is made by mixing bentonite with in-situ soil. Since the bentonite swelling is sensitive to chemicals, chemical compatibility is important for the hydraulic barrier performance of SB. Hydraulic conductivity tests using flexible-wall permeameter were conducted on SB specimens with various types and concentrations of chemicals in the pore water and/or in the permeant and with various bentonite powder contents. As a result, hydraulic barrier performance of SB was influenced by the chemical concentration in the pore water of original soil and bentonite powder content. In the case that SB specimens have damage parallel to the permeating direction, no significant leakage in the SB occurs by the self-sealing property of SB. In addition, the hydraulic conductivity values of SB have excellent correlation with their plastic indexes and swelling pr essures, thus these properties of SB have some possibility to be indicators for estimation of the hydraulic barrier performance of SB.

  13. Sequence alignment status and amplicon size difference affecting EST-SSR primer performance and polymorphism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little attention has been given to failed, poorly-performing, and non-polymorphic expressed sequence tag (EST) simple sequence repeat (SSR) primers. This is due in part to a lack of interest and value in reporting them but also because of the difficulty in addressing the causes of failure on a prime...

  14. An Investigation of How Perceptions of Mathematics Ability Can Affect Elementary Statistics Performance.

    ERIC Educational Resources Information Center

    Galagedera, Don; Woodward, George; Degamboda, Sunanda

    2000-01-01

    Investigates the effects of perceived mathematics ability (PMA) on the learning process with special reference to undergraduates (N=147) following an elementary statistics (ES) course. Concludes that PMA itself is not a good predictor of ES performance; rather, its effect may be challenged through interest, expected grade, and motivation to do…

  15. Performativity and Affectivity: Lesson Observations in England's Further Education Colleges

    ERIC Educational Resources Information Center

    Edgington, Ursula

    2013-01-01

    Teaching and learning observations (TLOs) are used in educational environments worldwide to measure and improve quality and support professional development. TLOs can be positive for teachers who enjoy opportunities to "perform" their craft and/or engage in professional dialogue. However, if this crucial, collaborative developmental…

  16. Generalizing Screen Inferiority--Does the Medium, Screen versus Paper, Affect Performance Even with Brief Tasks?

    ERIC Educational Resources Information Center

    Sidi, Yael; Ophir, Yael; Ackerman, Rakefet

    2016-01-01

    Screen inferiority in performance and metacognitive processes has been repeatedly found with text learning. Common explanations for screen inferiority relate to technological and physiological disadvantages associated with extensive reading on screen. However, recent studies point to lesser recruitment of mental effort on screen than on paper.…

  17. Self-Reported Stickiness of Mind-Wandering Affects Task Performance

    PubMed Central

    van Vugt, Marieke K.; Broers, Nico

    2016-01-01

    When asked to perform a certain task, we typically spend a decent amount of time thinking thoughts unrelated to that task–a phenomenon referred to as “mind-wandering.” It is thought that this mind-wandering is driven at least in part by our unfinished goals and concerns. Previous studies have shown that just after presenting a participant with their own concerns, their reports of task-unrelated thinking increased somewhat. However, effects of these concerns on task performance were somewhat inconsistent. In this study we take the opposite approach, and examine whether task performance depends on the self-reported thought content. Specifically, a particularly intriguing aspect of mind-wandering that has hitherto received little attention is the difficulty of disengaging from it, in other words, the “stickiness” of the thoughts. While presenting participants with their own concerns was not associated with clear effects on task performance, we showed that the reports of off-task thinking and variability of response times increased with the amount of self-reported stickiness of thoughts. This suggests that the stickiness of mind-wandering is a relevant variable, and participants are able to meaningfully report on it. PMID:27242636

  18. Does Experience in College Mathematics Courses Affect Elementary Arithmetic Performance in College Students?

    ERIC Educational Resources Information Center

    Weinstein, Lawrence; Laverghetta, Antonio

    2009-01-01

    Undergraduate and graduate students at Cameron University (N = 158) were given the D'Amore Test of Elementary Arithmetic to test whether or not experience in college mathematics courses might be associated with a relative increase in arithmetic performance compared to those students who had not taken college mathematics courses. We found that only…

  19. Self-Reported Stickiness of Mind-Wandering Affects Task Performance.

    PubMed

    van Vugt, Marieke K; Broers, Nico

    2016-01-01

    When asked to perform a certain task, we typically spend a decent amount of time thinking thoughts unrelated to that task-a phenomenon referred to as "mind-wandering." It is thought that this mind-wandering is driven at least in part by our unfinished goals and concerns. Previous studies have shown that just after presenting a participant with their own concerns, their reports of task-unrelated thinking increased somewhat. However, effects of these concerns on task performance were somewhat inconsistent. In this study we take the opposite approach, and examine whether task performance depends on the self-reported thought content. Specifically, a particularly intriguing aspect of mind-wandering that has hitherto received little attention is the difficulty of disengaging from it, in other words, the "stickiness" of the thoughts. While presenting participants with their own concerns was not associated with clear effects on task performance, we showed that the reports of off-task thinking and variability of response times increased with the amount of self-reported stickiness of thoughts. This suggests that the stickiness of mind-wandering is a relevant variable, and participants are able to meaningfully report on it. PMID:27242636

  20. Selected Organizational Factors Affecting Performance of Professional Nurses in North West Bank Governmental Hospitals

    ERIC Educational Resources Information Center

    Thulth, Ahida Saleem; Sayej, Sumaya

    2015-01-01

    Background: Organizational factors are considered to be the cornerstone in achieving psychological and professional security at work, which in turn are positively reflected in job performance both quantitatively and qualitatively. Aim of the Study: The study aimed to assess of selected organizational factors (workload, available recourses and…

  1. Confocal Microscopy and Flow Cytometry System Performance: Assessment of QA Parameters that affect data Quanitification

    EPA Science Inventory

    Flow and image cytometers can provide useful quantitative fluorescence data. We have devised QA tests to be used on both a flow cytometer and a confocal microscope to assure that the data is accurate, reproducible and precise. Flow Cytometry: We have provided two simple perform...

  2. Does Listening to Slow Tempo Classical Music During Independent Writing Affect Children's On-Task Performance?

    ERIC Educational Resources Information Center

    McKnight, Rosemary

    This project explored the effects of slow tempo classical music on children's on-task performance during independent writing. The project sample consisted of 24 students from a first grade classroom in the New York City Public School System. The students' on-task behavior was observed with and without use of slow tempo classical music playing, and…

  3. Primary Dysmenorrhea, Educational Performance, and Cognitive and Affective Variables in Adolescent Schoolgirls.

    ERIC Educational Resources Information Center

    Fontana, D.; Rees, Valerie

    1982-01-01

    Research among adolescent English schoolgirls indicated that although girls with primary dysmenorrhea appeared to be more neurotic than those who did not experience menstrual distress, there was no apparent difference between the two groups on cognitive and academic performance measures or in school attendance. (Author/MJL)

  4. Factors Affecting Performance of Agricultural Extension: Evidence from Democratic Republic of Congo

    ERIC Educational Resources Information Center

    Ragasa, Catherine; Ulimwengu, John; Randriamamonjy, Josee; Badibanga, Thaddee

    2016-01-01

    Purpose: As part of the institutional reforms and agricultural restructuring in the Democratic Republic of Congo (DRC), this paper provides an assessment of the performance of the agricultural extension system as well as factors explaining it. Method: This paper involves key informants' interviews and surveys of 107 extension organizations and 162…

  5. Does Competition Affect Schools' Performance? Evidence from Italy through OECD-PISA Data

    ERIC Educational Resources Information Center

    Agasisti, Tommaso

    2011-01-01

    This article evaluates the impact of competition on the performance of Italian schools. The study is based on policy experiments developed in 2000 by the Lombardy Regional government which introduced a voucher plan to encourage families to enrol their children in private schools. After this intervention, many other Regions launched similar…

  6. Does Eating Breakfast Affect the Performance of College Students on Biology Exams?

    ERIC Educational Resources Information Center

    Phillips, Gregory W.

    2005-01-01

    This study examined the breakfast eating habits of 1,259 college students over an eleven year period to determine if eating breakfast had an impact upon their grade on a General Biology exam. The study determined that there was a significant difference in the performance on the exam with a higher percent of the participants, who had eaten…

  7. Do Foreclosures Affect Boston Public School Student Academic Performance? Public Policy Brief No. 13-5

    ERIC Educational Resources Information Center

    Bradbury, Katharine; Burke, Mary A.; Triest, Robert K.

    2013-01-01

    Foreclosures have well-documented adverse consequences for families living in or owning properties undergoing foreclosure and on surrounding neighborhoods, but they may also have other costs. This policy brief summarizes our research on the impact of mortgage foreclosures on academic performance among Boston public school students. The data show…

  8. Micromechanical analysis of damping performance of piezoelectric structural fiber composites

    NASA Astrophysics Data System (ADS)

    Dai, Qingli; Ng, Kenny

    2010-04-01

    Recent studies showed that the active piezoelectric structural fiber (PSF) composites may achieve significant and simultaneous improvements in sensing/actuating, stiffness, fracture toughness and vibration damping. These characteristics can be of particular importance in various civil, mechanical and aerospace structures. This study firstly conducted the micromechanical finite element analysis to predict the elastic properties and piezoelectrical coupling parameters of a special type of an active PSF composite laminate. The PSF composite laminates are made of longitudinally poled PSFs that are unidirectionally deployed in the polymer binding matrix. The passive damping performance of these active composites was studied under the cyclic force loadings with different frequencies. It was found that the passive electric-mechanical coupling behavior can absorb limited dynamic energy and delay the structure responses with minimum viscoelastic damping. The actuating function of piezoelectric materials was then applied to reduce the dynamic mechanical deformation. The step voltage inputs were imposed to the interdigital electrodes of PSF laminate transducer along the poled direction. The cyclic pressure loading was applied transversely to the composite laminate. The electromechnical interaction with the 1-3 coupling parameter generated the transverse expansion, which can reduce the cyclic deformation evenly by shifting the response waves. This study shows the promise in using this type of active composites as actuators to improve stability of the structure dynamic.

  9. Structural analysis of amorphous phosphates using high performance liquid chromatography

    SciTech Connect

    Sales, B.C.; Boatner, L.A.; Chakoumakos, B.C.; McCallum, J.C.; Ramey, J.O.; Zuhr, R.A.

    1993-12-31

    Determining the atomic-scale structure of amorphous solids has proven to be a formidable scientific and technological problem for the past 100 years. The technique of high-performance liquid chromatography (HPLC) provides unique detailed information regarding the structure of partially disordered or amorphous phosphate solids. Applications of the experimental technique of HPLC to phosphate solids are reviewed, and examples of the type of information that can be obtained with HPLC are presented. Inorganic phosphates encompass a large class of important materials whose applications include: catalysts, ion-exchange media, solid electrolytes for batteries, linear and nonlinear optical components, chelating agents, synthetic replacements for bone and teeth, phosphors, detergents, and fertilizers. Phosphate ions also represent a unique link between living systems and the inorganic world.

  10. Team Assembly Mechanisms Determine Collaboration Network Structure and Team Performance

    PubMed Central

    Guimerà, Roger; Uzzi, Brian; Spiro, Jarrett; Nunes Amaral, Luís A.

    2007-01-01

    Agents in creative enterprises are embedded in networks that inspire, support, and evaluate their work. Here, we investigate how the mechanisms by which creative teams self-assemble determine the structure of these collaboration networks. We propose a model for the self-assembly of creative teams that has its basis in three parameters: team size, the fraction of newcomers in new productions, and the tendency of incumbents to repeat previous collaborations. The model suggests that the emergence of a large connected community of practitioners can be described as a phase transition. We find that team assembly mechanisms determine both the structure of the collaboration network and team performance for teams derived from both artistic and scientific fields. PMID:15860629

  11. Emotion and affect in mental imagery: do fear and anxiety manipulate mental rotation performance?

    PubMed Central

    Kaltner, Sandra; Jansen, Petra

    2014-01-01

    Little is known about the effects of fear as a basic emotion on mental rotation (MR) performance. We expected that the emotional arousal evoked by fearful stimuli presented prior to each MR trial would enhance MR performance. Regarding the influence of anxiety, high anxious participants are supposed to show slower responses and higher error rates in this specific visuo-spatial ability. Furthermore, with respect to the embodied cognition viewpoint we wanted to investigate if the influence of fear on MR performance is the same for egocentric and object-based transformations. To investigate this, we presented either negative or neutral images prior to each MR trial. Participants were allocated to the specific emotion in a randomized order. Results show that fear enhances MR performance, expressed by a higher MR speed. Interestingly, this influence is dependent on the type of transformation: it is restricted to egocentric rotations. Both observation of emotional stimuli and egocentric strategies are associated with left hemisphere activation which could explain a stronger influence on this type of transformation during observation. Another possible notion is the conceptual link between visuo-spatial perspective taking and empathy based on the co-activation of parietal areas. Stronger responses in egocentric transformations could result from this specific link. Regarding the influence of anxiety, participants with high scores on the trait-anxiety scale showed poor results in both reaction time and MR speed. Findings of impoverished recruitment of prefrontal attentional control in patients with high scores in trait anxiety could be the explanation for this reduced performance. PMID:25120508

  12. Timing Carbohydrate Beverage Intake During Prolonged Moderate Intensity Exercise Does Not Affect Cycling Performance

    PubMed Central

    SCHWEITZER, GEORGE G.; SMITH, JOHN D.; LECHEMINANT, JAMES D.

    2009-01-01

    Carbohydrate beverages consumed during long-term exercise have been shown to attenuate fatigue and improve performance; however, the optimal timing of ingestion is unclear. Therefore, the purpose of this study was to determine if timing the carbohydrate ingestion (continual loading (CL), front-loading (FL), and end-loading (EL)) during prolonged exercise influenced exercise performance in competitive cyclists. Ten well-trained cyclists completed three separate exercise bouts on a bicycle ergometer, each lasting 2 hours at an intensity of ~67% VO2 max, followed by a 15-minute “all out” time trial. In the CL trial, a carbohydrate beverage was ingested throughout the trial. In the FL trial, participants ingested a carbohydrate beverage during the first hour and a placebo beverage during the second hour. In the EL trial, a carbohydrate beverage was ingested during the second hour and a placebo during the first hour. The amount of carbohydrate consumed (75 g) was the same among conditions. The order of conditions was single-blinded, counterbalanced, and determined randomly. Performance was measured by the work output during the 15-minute performance ride. There were no differences in work output among the three conditions during the final time trial. In the first hour of exercise, peak venous blood glucose was highest in the FL condition. In the second hour, peak venous blood glucose was highest in the EL condition. Following the time trial, venous blood glucose levels were similar among CL, FL, and EL. Overall, the timing of carbohydrate beverage consumption during prolonged moderate intensity cycling did not alter cycling performance.

  13. Wearing knee wraps affects mechanical output and performance characteristics of back squat exercise.

    PubMed

    Lake, Jason P; Carden, Patrick J C; Shorter, Kath A

    2012-10-01

    The aim of this study was to investigate the effects of wearing knee wraps on mechanical output and performance characteristics of back squat exercise. Ten resistance trained men (back squat 1 repetition maximum [1RM]: 160.5 ± 18.4 kg) performed 6 single back squats with 80% 1RM, 3 wearing knee wraps, 3 without. Mechanical output was obtained from ground reaction force, performance characteristics from digitized motion footage obtained from a single high-speed digital camera. Wearing knee wraps led to a 39% reduction (0.09 compared with 0.11 m, p = 0.037) in horizontal barbell displacement that continued during the lifting phase. Lowering phase vertical impulse remained within 1% across conditions; however, the lowering phase was performed 45% faster (1.13 compared with 1.57 seconds). This demonstrated that vertical force applied to the center of mass during the lowering phase was considerably larger and was likely a consequence of the generation and storage of elastic energy within the knee wrap. Subsequent vertical impulse applied to the center of mass was 10% greater (192 compared with 169 N·s, p = 0.018). Mechanical work involved in vertically displacing the center of mass was performed 20% faster and was reflected by a 10% increase in peak power (2,121 compared with 1,841 W, p = 0.019). The elastic properties of knee wraps increased mechanical output but altered back squat technique in a way that is likely to alter the musculature targeted by the exercise and possibly compromise the integrity of the knee joint. Knee wraps should not be worn during the strength and condition process, and perceived weakness in the knee joint should be assessed and treated. PMID:22995993

  14. Study and Analyses on the Structural Performance of a Balance

    NASA Technical Reports Server (NTRS)

    Karkehabadi, R.; Rhew, R. D.; Hope, D. J.

    2004-01-01

    Strain-gauge balances for use in wind tunnels have been designed at Langley Research Center (LaRC) since its inception. Currently Langley has more than 300 balances available for its researchers. A force balance is inherently a critically stressed component due to the requirements of measurement sensitivity. The strain-gauge balances have been used in Langley s wind tunnels for a wide variety of aerodynamic tests, and the designs encompass a large array of sizes, loads, and environmental effects. There are six degrees of freedom that a balance has to measure. The balance s task to measure these six degrees of freedom has introduced challenging work in transducer development technology areas. As the emphasis increases on improving aerodynamic performance of all types of aircraft and spacecraft, the demand for improved balances is at the forefront. Force balance stress analysis and acceptance criteria are under review due to LaRC wind tunnel operational safety requirements. This paper presents some of the analyses and research done at LaRC that influence structural integrity of the balances. The analyses are helpful in understanding the overall behavior of existing balances and can be used in the design of new balances to enhance performance. Initially, a maximum load combination was used for a linear structural analysis. When nonlinear effects were encountered, the analysis was extended to include nonlinearities using MSC.Nastran . Because most of the balances are designed using Pro/Mechanica , it is desirable and efficient to use Pro/Mechanica for stress analysis. However, Pro/Mechanica is limited to linear analysis. Both Pro/Mechanica and MSC.Nastran are used for analyses in the present work. The structural integrity of balances and the possibility of modifying existing balances to enhance structural integrity are investigated.

  15. Can selected functional movement screen assessments be used to identify movement deficiencies that could affect multidirectional speed and jump performance?

    PubMed

    Lockie, Robert G; Schultz, Adrian B; Jordan, Corrin A; Callaghan, Samuel J; Jeffriess, Matthew D; Luczo, Tawni M

    2015-01-01

    The Functional Movement Screen (FMS) includes lower-body focused tests (deep squat [DS], hurdle step, in-line lunge) that could assist in identifying movement deficiencies affecting multidirectional sprinting and jumping, which are important qualities for team sports. However, the hypothesized relationship with athletic performance lacks supportive research. This study investigated relationships between the lower-body focused screens and overall FMS performance and multidirectional speed and jumping capabilities in team sport athletes. Twenty-two healthy men were assessed in the FMS, and multidirectional speed (0- to 5-m, 0- to 10-m, 0- to 20-m sprint intervals; 505 and between-leg turn differences, modified T-test and differences between initial movement to the left or right); and bilateral and unilateral multidirectional jumping (vertical [VJ], standing long [SLJ], and lateral jump) tests. Pearson's correlations (r) were used to calculate relationships between screening scores and performance tests (p ≤ 0.05). After the determination of any screens relating to athletic performance, subjects were stratified into groups (3 = high-performing group; 2 = intermediate-performing group; 1 = low-performing group) to investigate movement compensations. A 1-way analysis of variance (p ≤ 0.05) determined any between-group differences. There were few significant correlations. The DS did moderately correlate with between-leg 505 difference (r = -0.423), and bilateral VJ (r = -0.428) and SLJ (r = -0.457). When stratified into groups according to DS score, high performers had a 13% greater SLJ when compared with intermediate performers, which was the only significant result. The FMS seems to have minimal capabilities for identifying movement deficiencies that could affect multidirectional speed and jumping in male team sport athletes. PMID:25028993

  16. Vane structure design trade-off and performance analysis

    NASA Astrophysics Data System (ADS)

    Breault, Robert P.

    1989-04-01

    The APART/PADE and ASAP stray-light software packages (Breault, 1988) are applied to the design of vane structures to block direct propagation paths from the surfaces of optical baffles to other system components. Results for several typical systems are presented in extensive tables and graphs and analyzed. It is shown that vane angle and depth are significant parameters only for the first-order propagation path. Also evaluated are the amounts of particulate debris produced by degraded vane coatings and the effects of the resulting surface contamination on system performance.

  17. Effects of structure flexibility on horizontal axis wind turbine performances

    NASA Astrophysics Data System (ADS)

    Coiro, D. P.; Daniele, E.; Scherillo, F.

    2013-10-01

    This work illustrates the effects of flexibility of rotor blades and turbine tower on the performances of an horizontal axis wind turbine (HAWT) designed by our ADAG research group, by means of several example applied on a recent project for a active pitch controlled upwind 60 kW HAWT. The influence of structural flexibility for blade only, tower only and blade coupled with tower configuration is investigated using an aero-elastic computer-aided engineering (CAE) tool for horizontal axis wind turbines named FAST developed at National Renewable Energy Laboratory (NREL) of USA. For unsteady inflow conditions in front of the isolated HAWT the performances in rigid and flexible operation mode are computed and compared in order to illustrate the limitation included within a classical rigid body approach to wind turbine simulation.

  18. Performance characterization of structured light-based fingerprint scanner

    NASA Astrophysics Data System (ADS)

    Hassebrook, Laurence G.; Wang, Minghao; Daley, Raymond C.

    2013-05-01

    Our group believes that the evolution of fingerprint capture technology is in transition to include 3-D non-contact fingerprint capture. More specifically we believe that systems based on structured light illumination provide the highest level of depth measurement accuracy. However, for these new technologies to be fully accepted by the biometric community, they must be compliant with federal standards of performance. At present these standards do not exist for this new biometric technology. We propose and define a set of test procedures to be used to verify compliance with the Federal Bureau of Investigation's image quality specification for Personal Identity Verification single fingerprint capture devices. The proposed test procedures include: geometric accuracy, lateral resolution based on intensity or depth, gray level uniformity and flattened fingerprint image quality. Several 2-D contact analogies, performance tradeoffs and optimization dilemmas are evaluated and proposed solutions are presented.

  19. Multilevel polarization shift keying: Optimum receiver structure and performance evaluation

    SciTech Connect

    Benedetto, S.; Poggiolini, P.T.

    1994-02-01

    Multilevel digital coherent optical modulation schemes based on the state of polarization of a fully polarized lightwave are proposed and analyzed. Based on the complete statistical characterization of the Stokes parameters, extracted though appropriate signal processing in the presence of shot and additive gaussian noise, the optimum maximum likelihood receiver operating symbol by symbol is derived. The exact performance in terms of the average symbol error probability is found. Optimum constellations for the case of equipower 4, 8, 16 and 32 signals are found on the basis of the minimization of the error probability for a given average power. Their performance turns out to be promising as compared to other standard modulation techniques. The spectral analysis of polarization modulated signals is presented. A new receiver structure, which solves the problem of the excess penalties incurred in the presence of channel dichroism, is proposed and analyzed. 22 refs.

  20. Drama and the Representation of Affect--Structures of Feeling and Signs of Learning

    ERIC Educational Resources Information Center

    Franks, Anton

    2014-01-01

    The way in which school students represent affective aspects of human relationships in drama and what this reveals about learning in drama is the focus of this paper. Such an enquiry traverses the borders between affect, intellect, and physicality. Affect and its representation in drama have been themes in the history of drama and theatre and is a…

  1. A Structure for the Affective Domain in Relation to Science Education.

    ERIC Educational Resources Information Center

    Klopfer, Leopold E.

    A classification scheme for the affective domain in relation to science education is presented in this article to clarify student's affective behaviors and their representative phenomena. Discussion is made in connection with the content-objectives grid in the cognitive domain. An analogous grid for the affective domain is delineated by a…

  2. Non-conscious visual cues related to affect and action alter perception of effort and endurance performance

    PubMed Central

    Blanchfield, Anthony; Hardy, James; Marcora, Samuele

    2014-01-01

    The psychobiological model of endurance performance proposes that endurance performance is determined by a decision-making process based on perception of effort and potential motivation. Recent research has reported that effort-based decision-making during cognitive tasks can be altered by non-conscious visual cues relating to affect and action. The effects of these non-conscious visual cues on effort and performance during physical tasks are however unknown. We report two experiments investigating the effects of subliminal priming with visual cues related to affect and action on perception of effort and endurance performance. In Experiment 1 thirteen individuals were subliminally primed with happy or sad faces as they cycled to exhaustion in a counterbalanced and randomized crossover design. A paired t-test (happy vs. sad faces) revealed that individuals cycled significantly longer (178 s, p = 0.04) when subliminally primed with happy faces. A 2 × 5 (condition × iso-time) ANOVA also revealed a significant main effect of condition on rating of perceived exertion (RPE) during the time to exhaustion (TTE) test with lower RPE when subjects were subliminally primed with happy faces (p = 0.04). In Experiment 2, a single-subject randomization tests design found that subliminal priming with action words facilitated a significantly longer TTE (399 s, p = 0.04) in comparison to inaction words. Like Experiment 1, this greater TTE was accompanied by a significantly lower RPE (p = 0.03). These experiments are the first to show that subliminal visual cues relating to affect and action can alter perception of effort and endurance performance. Non-conscious visual cues may therefore influence the effort-based decision-making process that is proposed to determine endurance performance. Accordingly, the findings raise notable implications for individuals who may encounter such visual cues during endurance competitions, training, or health related exercise. PMID:25566014

  3. Flow structure, performance and scaling of acoustic jets

    NASA Astrophysics Data System (ADS)

    Muller, Michael Oliver

    Acoustic jets are studied, with an emphasis on their flow structure, performance, and scaling. The ultimate goal is the development of a micromachined acoustic jet for propulsion of a micromachined airborne platform, as well as integrated cooling and pumping applications. Scaling suggests an increase in performance with decreasing size, motivating the use of micro-technology. Experimental studies are conducted at three different orders of magnitude in size, each closely following analytic expectations. The jet creates a periodic vortical structure, the details of which are a function of amplitude. At small actuation amplitude, but still well above the linear acoustic regime, the flow structure consists of individual vortex rings, propagating away from the nozzle, formed during the outstroke of the acoustic cavity. At large amplitude, a trail of vorticity forms between the periodic vortex rings. Approximately corresponding to these two flow regions are two performance regimes. At low amplitude, the jet thrust increases with the fourth power of the amplitude; and at large amplitude, the thrust equals the momentum flux ejected during the output stroke, and increases as the square of the amplitude. Resonance of the cavity, at Reynolds numbers greater than approximately 10, enhances the jet performance beyond the incompressible behavior. Gains of an order of magnitude in the jet velocity occur at Reynolds numbers of approximately 100, and the data suggest further gains with increasing Reynolds number. The smallest geometries tested are micromachined acoustic jets, manufactured using MEMS technology. The throat dimensions are 50 by 200 mum, and the overall device size is approximately 1 mm 2, with eight throats per device. Several jets are manufactured in an array, to suit any given application. The performance is very dependent on frequency, with a sharp peak at the system resonance, occurring at approximately 70 kHz (inaudible). The mean jet velocity of these devices

  4. Structure and Validity of Affect Knowledge Test (AKT) in a Sample of Italian Preschoolers.

    PubMed

    Sette, Stefania; Bassett, Hideko H; Baumgartner, Emma; Denham, Susanne A

    2015-01-01

    The authors' main goals were to examine whether the Affect Knowledge Test's (AKT) factor structure would be represented by a two-factor model (i.e., emotion recognition and situation knowledge) or by a one-factor model in Italian preschoolers (N = 164; M = 4.24 years, SD = 1.09 years). The concurrent validity of the AKT was further examined using measures of social competence. The findings replicated a model of emotion knowledge, with emotion recognition and situation knowledge as distinct but interrelated factors. Gender and age differences showed that older children and girls displayed higher scores in situation knowledge than younger children and boys. Additionally, our validity model of the AKT demonstrated that emotion recognition preceded situation knowledge, which in turn was positively related to children's sensitive or cooperative behaviors and negatively associated with anxious or withdrawn behaviors. Our results suggest that the use of the AKT may help the teachers to evaluate children's level on emotional knowledge that in turn might impact on children's positive social relationships within classroom in Italy. PMID:26287657

  5. Correlation between structural diversity and catabolic versatility of metal-affected bacteria in soil

    NASA Astrophysics Data System (ADS)

    Wenderoth, D. F.; Reber, H. H.; Timmis, K. N.

    2003-04-01

    Application of sewage sludge to an agricultural field resulted in contamination of metal. Metal affects on the the structural diversity and the catabolic versatility of bacteria capable of growing in the absence of growing factors were studied six years after sludge application. The number of strain clusters as estimated by amplified ribosomal restriction analysis (ADRDA) was reduced by 39% when comparing isolates from the control and the most contaminated soil. Concomittantly, the average number of aromatic acids utilized per isolate from among 21 substrates tested decreased from 12.28 to 5.23. This loss in catabolic versatility was greater in Gram-negative (68%) than in Gram-positive bacteria (49%). Due to bioenergetic reasons discussed, it is supposed that the catabolic versatility between Gram-negative and Gram-positive bacteria and the greater loss of this property in the former may explain why, in metal contaminated soils, Grtam-negatives are selected at the expense of Gram-positive bacteria.

  6. Population structure of Columbia spotted frogs (Rana luteiventris) is strongly affected by the landscape

    USGS Publications Warehouse

    Funk, W.C.; Blouin, M.S.; Corn, P.S.; Maxell, B.A.; Pilliod, D.S.; Amish, S.; Allendorf, F.W.

    2005-01-01

    Landscape features such as mountains, rivers, and ecological gradients may strongly affect patterns of dispersal and gene flow among populations and thereby shape population dynamics and evolutionary trajectories. The landscape may have a particularly strong effect on patterns of dispersal and gene flow in amphibians because amphibians are thought to have poor dispersal abilities. We examined genetic variation at six microsatellite loci in Columbia spotted frogs (Rana luteiventris) from 28 breeding ponds in western Montana and Idaho, USA, in order to investigate the effects of landscape structure on patterns of gene flow. We were particularly interested in addressing three questions: (i) do ridges act as barriers to gene flow? (ii) is gene flow restricted between low and high elevation ponds? (iii) does a pond equal a 'randomly mating population' (a deme)? We found that mountain ridges and elevational differences were associated with increased genetic differentiation among sites, suggesting that gene flow is restricted by ridges and elevation in this species. We also found that populations of Columbia spotted frogs generally include more than a single pond except for very isolated ponds. There was also evidence for surprisingly high levels of gene flow among low elevation sites separated by large distances. Moreover, genetic variation within populations was strongly negatively correlated with elevation, suggesting effective population sizes are much smaller at high elevation than at low elevation. Our results show that landscape features have a profound effect on patterns of genetic variation in Columbia spotted frogs.

  7. Does the tail wag the dog? How the structure of a glycosylphosphatidylinositol anchor affects prion formation.

    PubMed

    Bate, Clive; Nolan, William; Williams, Alun

    2016-03-01

    There is increasing interest in the role of the glycosylphosphatidylinositol (GPI) anchor attached to the cellular prion protein (PrP(C)). Since GPI anchors can alter protein targeting, trafficking and cell signaling, our recent study examined how the structure of the GPI anchor affected prion formation. PrP(C) containing a GPI anchor from which the sialic acid had been removed (desialylated PrP(C)) was not converted to PrP(Sc) in prion-infected neuronal cell lines and in scrapie-infected primary cortical neurons. In uninfected neurons desialylated PrP(C) was associated with greater concentrations of gangliosides and cholesterol than PrP(C). In addition, the targeting of desialylated PrP(C) to lipid rafts showed greater resistance to cholesterol depletion than PrP(C). The presence of desialylated PrP(C) caused the dissociation of cytoplasmic phospholipase A2 (cPLA2) from PrP-containing lipid rafts, reduced the activation of cPLA2 and inhibited PrP(Sc) production. We conclude that the sialic acid moiety of the GPI attached to PrP(C) modifies local membrane microenvironments that are important in PrP-mediated cell signaling and PrP(Sc) formation. PMID:26901126

  8. Proper nozzle location, bit profile, and cutter arrangement affect PDC-bit performance significantly

    SciTech Connect

    Garcia-Gavito, D.; Azar, J.J.

    1994-09-01

    During the past 20 years, the drilling industry has looked to new technology to halt the exponentially increasing costs of drilling oil, gas, and geothermal wells. This technology includes bit design innovations to improve overall drilling performance and reduce drilling costs. These innovations include development of drag bits that use PDC cutters, also called PDC bits, to drill long, continuous intervals of soft to medium-hard formations more economically than conventional three-cone roller-cone bits. The cost advantage is the result of higher rates of penetration (ROP's) and longer bit life obtained with the PDC bits. An experimental study comparing the effects of polycrystalline-diamond-compact (PDC)-bit design features on the dynamic pressure distribution at the bit/rock interface was conducted on a full-scale drilling rig. Results showed that nozzle location, bit profile, and cutter arrangement are significant factors in PDC-bit performance.

  9. Coordination Chemistry in magnesium battery electrolytes: how ligands affect their performance

    PubMed Central

    Shao, Yuyan; Liu, Tianbiao; Li, Guosheng; Gu, Meng; Nie, Zimin; Engelhard, Mark; Xiao, Jie; Lv, Dongping; Wang, Chongmin; Zhang, Ji-Guang; Liu, Jun

    2013-01-01

    Magnesium battery is potentially a safe, cost-effective, and high energy density technology for large scale energy storage. However, the development of magnesium battery has been hindered by the limited performance and the lack of fundamental understandings of electrolytes. Here, we present a study in understanding coordination chemistry of Mg(BH4)2 in ethereal solvents. The O donor denticity, i.e. ligand strength of the ethereal solvents which act as ligands to form solvated Mg complexes, plays a significant role in enhancing coulombic efficiency of the corresponding solvated Mg complex electrolytes. A new electrolyte is developed based on Mg(BH4)2, diglyme and LiBH4. The preliminary electrochemical test results show that the new electrolyte demonstrates a close to 100% coulombic efficiency, no dendrite formation, and stable cycling performance for Mg plating/stripping and Mg insertion/de-insertion in a model cathode material Mo6S8 Chevrel phase. PMID:24185310

  10. Coordination chemistry in magnesium battery electrolytes: how ligands affect their performance.

    PubMed

    Shao, Yuyan; Liu, Tianbiao; Li, Guosheng; Gu, Meng; Nie, Zimin; Engelhard, Mark; Xiao, Jie; Lv, Dongping; Wang, Chongmin; Zhang, Ji-Guang; Liu, Jun

    2013-01-01

    Magnesium battery is potentially a safe, cost-effective, and high energy density technology for large scale energy storage. However, the development of magnesium battery has been hindered by the limited performance and the lack of fundamental understandings of electrolytes. Here, we present a study in understanding coordination chemistry of Mg(BH₄)₂ in ethereal solvents. The O donor denticity, i.e. ligand strength of the ethereal solvents which act as ligands to form solvated Mg complexes, plays a significant role in enhancing coulombic efficiency of the corresponding solvated Mg complex electrolytes. A new electrolyte is developed based on Mg(BH₄)₂, diglyme and LiBH₄. The preliminary electrochemical test results show that the new electrolyte demonstrates a close to 100% coulombic efficiency, no dendrite formation, and stable cycling performance for Mg plating/stripping and Mg insertion/de-insertion in a model cathode material Mo₆S₈ Chevrel phase. PMID:24185310

  11. Coordination Chemistry in magnesium battery electrolytes: how ligands affect their performance

    DOE PAGESBeta

    Shao, Yuyan; Liu, Tianbiao L.; Li, Guosheng; Gu, Meng; Nie, Zimin; Engelhard, Mark H.; Xiao, Jie; Lu, Dongping; Wang, Chong M.; Zhang, Jiguang; et al

    2013-11-04

    Magnesium battery is potentially a safe, cost-effective, and high energy density technology for large scale energy storage. However, the development of magnesium battery has been hindered by the limited performance and the lack of fundamental understandings of electrolytes. Here, we present a coordination chemistry study of Mg(BH4)2 in ethereal solvents. The O donor denticity, i.e. ligand strength of the ethereal solvents which act as ligands to form solvated Mg complexes, plays a significant role in enhancing coulombic efficiency of the corresponding solvated Mg complex electrolytes. A new and safer electrolyte is developed based on Mg(BH4)2, diglyme and optimized LiBH4 additive.more » The new electrolyte demonstrates 100% coulombic efficiency, no dendrite formation, and stable cycling performance with the cathode capacity retention of ~90% for 300 cycles in a prototype magnesium battery.« less

  12. Coordination Chemistry in magnesium battery electrolytes: how ligands affect their performance

    SciTech Connect

    Shao, Yuyan; Liu, Tianbiao L.; Li, Guosheng; Gu, Meng; Nie, Zimin; Engelhard, Mark H.; Xiao, Jie; Lu, Dongping; Wang, Chong M.; Zhang, Jiguang; Liu, Jun

    2013-11-04

    Magnesium battery is potentially a safe, cost-effective, and high energy density technology for large scale energy storage. However, the development of magnesium battery has been hindered by the limited performance and the lack of fundamental understandings of electrolytes. Here, we present a coordination chemistry study of Mg(BH4)2 in ethereal solvents. The O donor denticity, i.e. ligand strength of the ethereal solvents which act as ligands to form solvated Mg complexes, plays a significant role in enhancing coulombic efficiency of the corresponding solvated Mg complex electrolytes. A new and safer electrolyte is developed based on Mg(BH4)2, diglyme and optimized LiBH4 additive. The new electrolyte demonstrates 100% coulombic efficiency, no dendrite formation, and stable cycling performance with the cathode capacity retention of ~90% for 300 cycles in a prototype magnesium battery.

  13. 40 CFR Table 3 to Subpart Nnnnn of... - Performance Test Requirements for HCl Production Affected Sources

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: Hydrochloric Acid Production Pt. 63, Subpt. NNNNN, Table 3 Table 3 to Subpart NNNNN of Part 63—Performance Test... of traverse points a. Method 1 or 1A in appendix A to 40 CFR part 60 of this chapter i. If complying.... Determine velocity and volumetric flow rate Method 2, 2A, 2C, 2D, 2F, or 2G in appendix A to 40 CFR part...

  14. 40 CFR Table 3 to Subpart Nnnnn of... - Performance Test Requirements for HCl Production Affected Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: Hydrochloric Acid Production Pt. 63, Subpt. NNNNN, Table 3 Table 3 to Subpart NNNNN of Part 63—Performance Test... of traverse points a. Method 1 or 1A in appendix A to 40 CFR part 60 of this chapter i. If complying.... Determine velocity and volumetric flow rate Method 2, 2A, 2C, 2D, 2F, or 2G in appendix A to 40 CFR part...

  15. 40 CFR Table 3 to Subpart Nnnnn of... - Performance Test Requirements for HCl Production Affected Sources

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: Hydrochloric Acid Production Pt. 63, Subpt. NNNNN, Table 3 Table 3 to Subpart NNNNN of Part 63—Performance Test... of traverse points a. Method 1 or 1A in appendix A to 40 CFR part 60 of this chapter i. If complying.... Determine velocity and volumetric flow rate Method 2, 2A, 2C, 2D, 2F, or 2G in appendix A to 40 CFR part...

  16. 40 CFR Table 3 to Subpart Nnnnn of... - Performance Test Requirements for HCl Production Affected Sources

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Hydrochloric Acid Production Pt. 63, Subpt. NNNNN, Table 3 Table 3 to Subpart NNNNN of Part 63—Performance Test... of traverse points a. Method 1 or 1A in appendix A to 40 CFR part 60 of this chapter i. If complying.... Determine velocity and volumetric flow rate Method 2, 2A, 2C, 2D, 2F, or 2G in appendix A to 40 CFR part...

  17. 40 CFR Table 3 to Subpart Nnnnn of... - Performance Test Requirements for HCl Production Affected Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: Hydrochloric Acid Production Pt. 63, Subpt. NNNNN, Table 3 Table 3 to Subpart NNNNN of Part 63—Performance Test... of traverse points a. Method 1 or 1A in appendix A to 40 CFR part 60 of this chapter i. If complying.... Determine velocity and volumetric flow rate Method 2, 2A, 2C, 2D, 2F, or 2G in appendix A to 40 CFR part...

  18. Does the company's economic performance affect access to occupational health services?

    PubMed Central

    Kankaanpää, Eila; Suhonen, Aki; Valtonen, Hannu

    2009-01-01

    Background In Finland like in many other countries, employers are legally obliged to organize occupational health services (OHS) for their employees. Because employers bear the costs of OHS it could be that in spite of the legal requirement OHS expenditure is more determined by economic performance of the company than by law. Therefore, we explored whether economic performance was associated with the companies' expenditure on occupational health services. Methods We used a prospective design to predict expenditure on OHS in 2001 by a company's economic performance in 1999. Data were provided by Statistics Finland and expressed by key indicators for profitability, solidity and liquidity and by the Social Insurance Institution as employers' reimbursement applications for OHS costs. The data could be linked at the company level. Regression analysis was used to study associations adjusted for various confounders. Results Nineteen percent of the companies (N = 6 155) did not apply for reimbursement of OHS costs in 2001. The profitability of the company represented by operating margin in 1999 and adjusted for type of industry was not significantly related to the company's probability to apply for reimbursement of the costs in 2001 (OR = 1.00, 95%CI: 0.99 to 1.01). Profitability measured as operating profit in 1999 and adjusted for type of industry was not significantly related to costs for curative medical services (Beta -0.001, 95%CI: -0.00 to 0.11) nor to OHS cost of prevention in 2001 (Beta -0.001, 95%CI: -0.00 to 0.00). Conclusion We did not find a relation between the company's economic performance and expenditure on OHS in Finland. We suppose that this is due to legislation obliging employers to provide OHS and the reimbursement system both being strong incentives for employers. PMID:19725952

  19. Does noise affect learning? A short review on noise effects on cognitive performance in children

    PubMed Central

    Klatte, Maria; Bergström, Kirstin; Lachmann, Thomas

    2013-01-01

    The present paper provides an overview of research concerning both acute and chronic effects of exposure to noise on children's cognitive performance. Experimental studies addressing the impact of acute exposure showed negative effects on speech perception and listening comprehension. These effects are more pronounced in children as compared to adults. Children with language or attention disorders and second-language learners are still more impaired than age-matched controls. Noise-induced disruption was also found for non-auditory tasks, i.e., serial recall of visually presented lists and reading. The impact of chronic exposure to noise was examined in quasi-experimental studies. Indoor noise and reverberation in classroom settings were found to be associated with poorer performance of the children in verbal tasks. Regarding chronic exposure to aircraft noise, studies consistently found that high exposure is associated with lower reading performance. Even though the reported effects are usually small in magnitude, and confounding variables were not always sufficiently controlled, policy makers responsible for noise abatement should be aware of the potential impact of environmental noise on children's development. PMID:24009598

  20. Experimental parameters affecting the Morris water maze performance of a mouse model of Down syndrome.

    PubMed

    Stasko, Melissa R; Costa, Alberto C S

    2004-09-23

    The Ts65Dn mouse is the most studied and genetically the most complete animal model of Down syndrome (DS) available. These mice display many DS-like features, including performance deficits in different behavioral tasks, motor dysfunction, and age-dependent loss of cholinergic markers in the basal forebrain. At present, the only robust data demonstrating a behavioral deficit potentially associated with learning and memory in Ts65Dn mice less than 6 months old have come from studies that used some variation of the Morris water maze task. However, the specific features of the water maze deficits seen in these animals are still poorly defined. This study is an initial attempt to bridge this knowledge gap. We investigated three major factors potentially influencing the performance of Ts65Dn mice in the water maze: (1) order in which the test is executed; (2) age of the animals; and (3) levels of aversiveness associated with the test. Measurements of plasma corticosterone levels and core body temperature after swimming were also carried out in additional subsets of mice. Overall, we found that the behavioral phenotype of Ts65Dn mice was milder than previously described in the literature. Additionally, Ts65Dn mice were significantly more responsive to potential stressors and more prone to swim-induced hypothermia than euploid control animals. More studies are needed to tease out further the potential effects of confounding factors on the performance of Ts65Dn mice. PMID:15302106

  1. Embodied Information in Cognitive Tasks: Haptic Weight Sensations Affect Task Performance and Processing Style

    PubMed Central

    Kaspar, Kai; Vennekötter, Alina

    2015-01-01

    Research in the field of embodied cognition showed that incidental weight sensations influence peoples’ judgments about a variety of issues and objects. Most studies found that heaviness compared to lightness increases the perception of importance, seriousness, and potency. In two experiments, we broadened this scope by investigating the impact of weight sensations on cognitive performance. In Experiment 1, we found that the performance in an anagram task was reduced when participants held a heavy versus a light clipboard in their hands. Reduced performance was accompanied by an increase in the perceived effort. In Experiment 2, a heavy clipboard elicited a specific response heuristic in a two-alternative forced-choice task. Participants showed a significant right side bias when holding a heavy clipboard in their hands. After the task, participants in the heavy clipboard condition reported to be more frustrated than participants in the light clipboard condition. In both experiments, we did not find evidence for mediated effects that had been proposed by previous literature. Overall, the results indicate that weight effects go beyond judgment formation and highlight new avenues for future research. PMID:26421084

  2. Does noise affect learning? A short review on noise effects on cognitive performance in children.

    PubMed

    Klatte, Maria; Bergström, Kirstin; Lachmann, Thomas

    2013-01-01

    The present paper provides an overview of research concerning both acute and chronic effects of exposure to noise on children's cognitive performance. Experimental studies addressing the impact of acute exposure showed negative effects on speech perception and listening comprehension. These effects are more pronounced in children as compared to adults. Children with language or attention disorders and second-language learners are still more impaired than age-matched controls. Noise-induced disruption was also found for non-auditory tasks, i.e., serial recall of visually presented lists and reading. The impact of chronic exposure to noise was examined in quasi-experimental studies. Indoor noise and reverberation in classroom settings were found to be associated with poorer performance of the children in verbal tasks. Regarding chronic exposure to aircraft noise, studies consistently found that high exposure is associated with lower reading performance. Even though the reported effects are usually small in magnitude, and confounding variables were not always sufficiently controlled, policy makers responsible for noise abatement should be aware of the potential impact of environmental noise on children's development. PMID:24009598

  3. Carbohydrate and Caffeine Mouth Rinses Do Not Affect Maximum Strength and Muscular Endurance Performance.

    PubMed

    Clarke, Neil D; Kornilios, Evangelos; Richardson, Darren L

    2015-10-01

    Oral carbohydrate (CHO) rinsing has beneficial effects on endurance performance and caffeine (CAF) mouth rinsing either independently or in conjunction with CHO may enhance sprinting performance. However, the effects of CHO and CAF mouth rinses on resistance exercise have not been examined previously. The purpose of this study was to investigate the effects of CHO and CAF rinsing on maximum strength and muscular endurance performance. Fifteen recreationally resistance-trained males completed an exercise protocol, which involved a 1 repetition maximum (RM) bench press followed by 60% of their 1RM to failure in a double-blind, randomized, counterbalanced crossover design. Before exercise, 25 ml of a 6% (15 g; 0.20 ± 0.02 g·kg(-1)) CHO, 1.2% (300 mg; 3.9 ± 0.3 mg·kg(-1)) CAF, carbohydrate with caffeine (C + C) solutions, or water (placebo; PLA) were rinsed for 10 seconds. During the remaining session, no solution was rinsed (control; CON). All solutions were flavored with (200 mg) sucralose. Felt arousal was recorded pre- and post-rinse, and rating of perceived exertion (RPE) was recorded immediately after the repetitions to failure. There were no significant differences in 1RM (p = 0.808; ηp(2)= 0.02), the number of repetitions performed (p = 0.682; ηp(2)= 0.03), or the total exercise volume (p = 0.482; ηp(2)= 0.03) between conditions. Rating of perceived exertion was similar for all trials (p = 0.330; ηp(2)= 0.08), whereas Felt arousal increased as a consequence of rinsing (p = 0.001; ηp(2)= 0.58), but was not different between trials (p = 0.335; ηp(2)= 0.08). These results suggest that rinsing with a CHO and CAF solution either independently or combined has no significant effect on maximum strength or muscular endurance performance. PMID:25785703

  4. The DMRT3 'Gait keeper' mutation affects performance of Nordic and Standardbred trotters.

    PubMed

    Jäderkvist, K; Andersson, L S; Johansson, A M; Árnason, T; Mikko, S; Eriksson, S; Andersson, L; Lindgren, G

    2014-10-01

    In a previous study it was shown that a nonsense mutation in the DMRT3 gene alters the pattern of locomotion in horses and that this mutation has a strong positive impact on trotting performance of Standardbreds. One aim of this study was to test if racing performance and trotting technique in the Nordic (Coldblood) trotters are also influenced by the DMRT3 genotype. Another aim was to further investigate the effect of the mutation on performance in Standardbreds, by using a within-family analysis and genotype-phenotype correlations in a larger horse material than in the previous study. We genotyped 427 Nordic trotters and 621 Standardbreds for the DMRT3 nonsense mutation and a SNP in strong linkage disequilibrium with it. In Nordic trotters, we show that horses homozygous for the DMRT3 mutation (A) had significantly higher EBV for trotting performance traits than heterozygous (CA) or homozygous wild-type (CC) horses (P = 0.001). Furthermore, AA homozygotes had a higher proportion of victories and top 3 placings than horses heterozygous or homozygous wild-type, when analyzing performance data for the period 3 to 6 yr of age (P = 0.06 and P = 0.05, respectively). Another finding in the Nordic trotters was that the DMRT3 mutation influenced trotting technique (P = 2.1 × 10(-8)). Standardbred horses homozygous AA had significantly higher EBV for all traits than horses with at least 1 wild-type allele (CA and CC; P = 1.6 × 10(-16)). In a within-family analysis of Standardbreds, we found significant differences in several traits (e.g., earnings, P = 0.002; number of entered races, P = 0.004; and fraction of offspring that entered races, P = 0.002) among paternal half-sibs with genotype AA or CA sired by a CA stallion. For most traits, we found significant differences at young ages. For Nordic trotters, most of the results were significant at 3 yr of age but not for the older ages, and for the Standardbreds most of the results for the ages 3 to 5 were significant. For

  5. A functional MiR-124 binding-site polymorphism in IQGAP1 affects human cognitive performance.

    PubMed

    Yang, Lixin; Zhang, Rui; Li, Ming; Wu, Xujun; Wang, Jianhong; Huang, Lin; Shi, Xiaodong; Li, Qingwei; Su, Bing

    2014-01-01

    As a product of the unique evolution of the human brain, human cognitive performance is largely a collection of heritable traits. Rather surprisingly, to date there have been no reported cases to highlight genes that underwent adaptive evolution in humans and which carry polymorphisms that have a marked effect on cognitive performance. IQ motif containing GTPase activating protein 1 (IQGAP1), a scaffold protein, affects learning and memory in a dose-dependent manner. Its expression is regulated by miR-124 through the binding sites in the 3'UTR, where a SNP (rs1042538) exists in the core-binding motif. Here we showed that this SNP can influence the miR-target interaction both in vitro and in vivo. Individuals carrying the derived T alleles have higher IQGAP1 expression in the brain as compared to the ancestral A allele carriers. We observed a significant and male-specific association between rs1042538 and tactile performances in two independent cohorts. Males with the derived allele displayed higher tactual performances as compared to those with the ancestral allele. Furthermore, we found a highly diverged allele-frequency distribution of rs1042538 among world human populations, likely caused by natural selection and/or recent population expansion. These results suggest that current human populations still carry sequence variations that affect cognitive performances and that these genetic variants may likely have been subject to comparatively recent natural selection. PMID:25222038

  6. Crystal structure engineering for improved performance of emerging nanoscale devices

    NASA Astrophysics Data System (ADS)

    Chimalgi, Vinay Uday

    Recent advances in growth techniques and increasing number of experimental studies have made nanostructures grown along different crystallographic directions a reality. These new structures could not only benefit the electronic devices used in mainstream information technology but also show great promise for applications in lasers, solid-state lighting, near-field photolithography, free-space quantum cryptography, consumer displays, quantum computation, as well as diagnostic medicine and imaging. However, only few theoretical investigations have been performed on these structures due to the complex nature of the interplay of atomicity, structural fields, polarization, and quantum size-quantization, all strong function of the crystallographic direction. The objective of this work is mainly four-fold: (1) Integrate a computational framework employing a combination of fully atomistic valence force-field molecular mechanics and 20-band sp3s*d5-SO tight-binding based electronic band­structure models, and numerically investigate the effects of internal fields on the electronic and optical properties of zincblende InAs/GaAs quantum dots grown on (100), (110), and (111) orientated substrates. (2) Augment/extend the open source NEMO 3-D bandstructure simulator by incorporating a recently proposed first principles based model to gauge the importance of nonlinear piezoelectricity on the single-particle electronic states and interband optical transitions in emerging In(Ga)N/GaN disk-in-wire LED structures having c-plane and m-plane wurtzite crystal symmetry. (3) Coupling the NEMO 3-D software toolkit with a commercial TCAD simulator to determine the terminal electrical and optical characteristics of InGaN/GaN disk-in-wire LEDs; and (4) Finding an optimum crystallographic device for InGaN/GaN disk-in-wire LEDs to achieve improved internal quantum efficiency (IQE).

  7. Expertise affects representation structure and categorical activation of grasp postures in climbing.

    PubMed

    Bläsing, Bettina E; Güldenpenning, Iris; Koester, Dirk; Schack, Thomas

    2014-01-01

    In indoor rock climbing, the perception of object properties and the adequate execution of grasping actions highly determine climbers' performance. In two consecutive experiments, effects of climbing expertise on the cognitive activation of grasping actions following the presentation of climbing holds was investigated. Experiment 1 evaluated the representation of climbing holds in the long-term memory of climbers and non-climbers with the help of a psychometric measurement method. Within a hierarchical splitting procedure subjects had to decide about the similarity of required grasping postures. For the group of climbers, representation structures corresponded clearly to four grip types. In the group of non-climbers, representation structures differed more strongly than in climbers and did not clearly refer to grip types. To learn about categorical knowledge activation in Experiment 2, a priming paradigm was applied. Images of hands in grasping postures were presented as targets and images of congruent, neutral, or incongruent climbing holds were used as primes. Only in climbers, reaction times were shorter and error rates were smaller for the congruent condition than for the incongruent condition. The neutral condition resulted in intermediate performance. The findings suggest that perception of climbing holds activates the commonly associated grasping postures in climbers but not in non-climbers. The findings of this study give evidence that the categorization of visually perceived objects is fundamentally influenced by the cognitive-motor potential for interaction, which depends on the observer's experience and expertise. Thus, motor expertise not only facilitates precise action perception, but also benefits the perception of action-relevant objects. PMID:25309480

  8. Expertise affects representation structure and categorical activation of grasp postures in climbing

    PubMed Central

    Bläsing, Bettina E.; Güldenpenning, Iris; Koester, Dirk; Schack, Thomas

    2014-01-01

    In indoor rock climbing, the perception of object properties and the adequate execution of grasping actions highly determine climbers' performance. In two consecutive experiments, effects of climbing expertise on the cognitive activation of grasping actions following the presentation of climbing holds was investigated. Experiment 1 evaluated the representation of climbing holds in the long-term memory of climbers and non-climbers with the help of a psychometric measurement method. Within a hierarchical splitting procedure subjects had to decide about the similarity of required grasping postures. For the group of climbers, representation structures corresponded clearly to four grip types. In the group of non-climbers, representation structures differed more strongly than in climbers and did not clearly refer to grip types. To learn about categorical knowledge activation in Experiment 2, a priming paradigm was applied. Images of hands in grasping postures were presented as targets and images of congruent, neutral, or incongruent climbing holds were used as primes. Only in climbers, reaction times were shorter and error rates were smaller for the congruent condition than for the incongruent condition. The neutral condition resulted in intermediate performance. The findings suggest that perception of climbing holds activates the commonly associated grasping postures in climbers but not in non-climbers. The findings of this study give evidence that the categorization of visually perceived objects is fundamentally influenced by the cognitive-motor potential for interaction, which depends on the observer's experience and expertise. Thus, motor expertise not only facilitates precise action perception, but also benefits the perception of action-relevant objects. PMID:25309480

  9. Topographic changes detection through Structure-from-Motion in agricultural lands affected by erosion processes

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Pradetto Sordo, Nicoletta; Burguet, Maria; Di Prima, Simone; Terol Esparza, Enric; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Throughout the world, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas (Cerdà et al., 2009; Cerdan et al., 2010; García-Ruiz, 2010). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as land-use changes on large scales and unsustainable farming practices (Boardman et al., 1990; Cerdà 1994; Montgomery, 2007). Tillage operations, combined with weather conditions, are recognized to primarily influence soil erosion rates. If, on one hand, tillage operations cause uniform changes based on the tool used, on the other, weather conditions, such as rainfalls, produce more random changes, less easily traceable (Snapir et al., 2014). Within this context, remote-sensing technologies can facilitate the detection and quantification of these topographic changes. In particular, a real opportunity and challenge is offered by the low-cost and flexible photogrammetric technique, called 'Structure-from-Motion' (SfM), combined with the use of smartphones (Micheletti et al., 2014; Prosdocimi et al., 2015). This represents a significant advance compared with more expensive technologies and applications (e.g. Terrestrial Laser Scanner - TLS) (Tarolli, 2014). This work wants to test the Structure from Motion to obtain high-resolution topography for the detection of topographic changes in agricultural lands affected by erosion processes. Two case studies were selected: i) a tilled plot characterized by bare soil and affected by rill erosion located in the hilly countryside of Marche region (central Italy), and ii) a Mediterranean vineyard located within the province of Valencia (south eastern Spain) where rainfall simulation experiments were carried out. Extensive photosets were obtained by using one standalone reflex digital camera and one smartphone built-in digital camera. Digital

  10. Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals

    PubMed Central

    Bowen, William D; den Heyer, Cornelia E; McMillan, Jim I; Iverson, Sara J

    2015-01-01

    Offspring size affects survival and subsequent reproduction in many organisms. However, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. We used data from a long-term study of individually marked gray seals (Halichoerus grypus; Fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspring. Between 1998 and 2002, 1182 newly weaned female pups were branded with unique permanent marks on Sable Island, Canada. Each year through 2012, all branded females returning to the breeding colony were identified in weekly censuses and a subset were captured and measured. Females that survived were significantly longer offspring than those not sighted, indicating size-selective mortality between weaning and recruitment. The probability of female survival to recruitment varied among cohorts and increased nonlinearly with body mass at weaning. Beyond 51.5 kg (mean population weaning mass) weaning mass did not influence the probability of survival. The probability of female survival to recruitment increased monotonically with body length at weaning. Body length at primiparity was positively related to her body length and mass at weaning. Three-day postpartum mass (proxy for birth mass) of firstborn pups was also positively related to body length of females when they were weaned. However, females that were longer or heavier when they were weaned did not wean heavier firstborn offspring. PMID:25897381

  11. Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals.

    PubMed

    Bowen, William D; den Heyer, Cornelia E; McMillan, Jim I; Iverson, Sara J

    2015-04-01

    Offspring size affects survival and subsequent reproduction in many organisms. However, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. We used data from a long-term study of individually marked gray seals (Halichoerus grypus; Fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspring. Between 1998 and 2002, 1182 newly weaned female pups were branded with unique permanent marks on Sable Island, Canada. Each year through 2012, all branded females returning to the breeding colony were identified in weekly censuses and a subset were captured and measured. Females that survived were significantly longer offspring than those not sighted, indicating size-selective mortality between weaning and recruitment. The probability of female survival to recruitment varied among cohorts and increased nonlinearly with body mass at weaning. Beyond 51.5 kg (mean population weaning mass) weaning mass did not influence the probability of survival. The probability of female survival to recruitment increased monotonically with body length at weaning. Body length at primiparity was positively related to her body length and mass at weaning. Three-day postpartum mass (proxy for birth mass) of firstborn pups was also positively related to body length of females when they were weaned. However, females that were longer or heavier when they were weaned did not wean heavier firstborn offspring. PMID:25897381

  12. Structure-function relationships affecting the sensing mechanism of monolayer-protected cluster doped xerogel amperometric glucose biosensors.

    PubMed

    DiPasquale, Luke T; Poulos, Nicholas G; Hall, Jackson R; Minocha, Aastha; Bui, Tram Anh; Leopold, Michael C

    2015-07-15

    A systematic study of the structure-function relationships critical to understanding the sensing mechanism of 1st generation amperometric glucose biosensors with an embedded nanoparticle (NP) network is presented. Xerogel-based films featuring embedded glucose oxidase enzyme and doped with alkanethiolate-protected gold NPs, known as monolayer protected clusters (MPCs), exhibit significantly enhanced performance compared to analogous systems without NPs including higher sensitivity, faster response time, and extended linear/dynamic ranges. The proposed mechanism involves diffusion of the glucose to glucose oxidase within the xerogel, enzymatic reaction production of H2O2 with subsequent diffusion to the embedded network of MPCs where it is oxidized, an event immediately reported via fast electron transfer (ET) through the MPC system to the working electrode. Various aspects of the film construct and strategy are systematically probed using amperometry, voltammetry, and solid-state electronic conductivity measurements, including the effects of MPC peripheral chain length, MPC functionalization via place-exchange reaction, MPC core size, and the MPC density or concentration within the xerogel composite films. The collective results of these experiments support the proposed mechanism and identify interparticle spacing and the electronic communication through the MPC network is the most significant factor in the sensing scheme with the diffusional aspects of the mechanism that may be affected by film/MPC hydrophobicity and functionality (i.e., glucose and H2O2 diffusion) shown to be less substantial contributors to the overall enhanced performance. Understanding the structure-function relationships of effective sensing schemes allows for the employment of the strategy for future biosensor design toward clinically relevant targets. PMID:25819004

  13. Sake Protein Supplementation Affects Exercise Performance and Biochemical Profiles in Power-Exercise-Trained Mice

    PubMed Central

    Chen, Yi-Ming; Lin, Che-Li; Wei, Li; Hsu, Yi-Ju; Chen, Kuan-Neng; Huang, Chi-Chang; Kao, Chin-Hsung

    2016-01-01

    Exercise and fitness training programs have attracted the public’s attention in recent years. Sports nutrition supplementation is an important issue in the global sports market. Purpose: In this study, we designed a power exercise training (PET) program with a mouse model based on a strength and conditional training protocol for humans. We tested the effect of supplementation with functional branched-chain amino acid (BCAA)-rich sake protein (SP) to determine whether the supplement had a synergistic effect during PET and enhanced athletic performance and resistance to fatigue. Methods: Male ICR mice were divided into three groups (n = 8 per group) for four-week treatment: sedentary controls with vehicle (SC), and PET and PET groups with SP supplementation (3.8 g/kg, PET + SP). Exercise performance was evaluated by forelimb grip strength and exhaustive swimming time as well as changes in body composition and anti-fatigue activity levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after a 15-min swimming exercise. The biochemical parameters were measured at the end of the experiment. Results: four-week PET significantly increased grip strength and exhaustive swimming time and decreased epididymal fat pad (EFP) weight and area. Levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and uric acid (UA) were significantly increased. PET + SP supplementation significantly decreased serum lactate, ammonia and CK levels after the 15-min swimming exercise. The resting serum levels of AST, ALT, CREA and UA were all significantly decreased with PET + SP. Conclusion: The PET program could increase the exercise performance and modulate the body composition of mice. PET with SP conferred better anti-fatigue activity, improved biochemical profiles, and may be an effective ergogenic aid in strength training. PMID:26907336

  14. Factors affecting postgraduate dental students' performance in a biostatistics and research design course.

    PubMed

    El Tantawi, Maha M A

    2009-05-01

    Comprehension of biostatistics and principles of research design is important for literature evaluation and evidence-based practice in dentistry as well as for researchers wishing to have their publications accepted by international journals. This study investigated the contribution of several factors to postgraduate dental student performance in a biostatistics and research design course. All of the subjects in this study were dental school graduates currently enrolled in postgraduate programs leading to master's or doctoral degrees. The seven factors selected for study were 1) learning style preferences assessed by the VARK questionnaire, 2) past academic performance at the bachelor's degree level, 3) age, 4) gender, 5) current postgraduate program (master's or Ph.D.), 6) lecture attendance, and 7) performance on a quiz conducted early in the course. Response rate was 64 percent. Using bivariate analysis, a statistically significant relationship was observed between final exam score and the following factors: bachelor's degree grade; having single or multiple learning preferences; having visual, aural, read-write, or kinesthetic learning style preference; percent of lectures attended; and quiz score (P<0.0001, 0.01, 0.02, 0.006, 0.04, 0.03, 0.03, and <0.0001 respectively). In regression analysis, significant predictors of final exam score were bachelor's degree grade, having aural learning preference, and quiz score. The findings suggest that dental educators should direct their attention to students who have difficulties at the beginning of the course and should match the learning preferences of as many students as possible by presenting information in different ways rather than focusing on a single method of delivering the course. PMID:19433536

  15. An investigation of factors affecting the performance of laboratory fume hoods

    SciTech Connect

    Altemose, B.A.

    1995-12-31

    A `user tracer gas test` was performed on laboratory hoods, with a human subject standing in front of the hood, to assess hood containment ability. The relationship of face velocity and cross draft variables to hood containment ability is investigated. The ability of these variables and other tests, such as smoke challenges or tracer gas tests performed with a manikin at the hood, to predict the results of the user tracer gas test is evaluated. All of the laboratory hoods tested in this study were identical bench top bypass hoods with horizontally sliding sashes. A face velocity traverse, cross draft measurements, a pitot traverse to measure exhaust flow, a smoke test, a manikin tracer gas test, and a user tracer gas test were performed on each hood in several different sash positions. Based on the data collected, face velocity, its distribution and variability, and the magnitude of cross drafts relative to face velocity are important variables in determining hood leakage. `Unblocked` vortices, formed such that no physical barrier exists between the vortex and room air or a person in front of the hood, are identified as important sites of leakage. For the hoods evaluated in this study, unblocked vortices were observed along the beveled side edges. The data support the hypothesis that in the presence of a person standing in front of the hood, leakage is more likely to occur if unblocked vortices are formed than if all vortices are blocked. Evidence suggests that cross drafts are more likely to cause leakage when flowing in a direction that may cause separated flow along a beveled edge of the hood and thereby augment the unblocked vortices along the edge. Results indicate that smoke tests, manikin tracer gas tests, and average face velocity all serve as useful monitoring techniques. Face velocity measurements and smoke tests, which are easy and inexpensive, may provide information which is as valuable as traditional manikin tracer gas tests.

  16. Intra-day signal instabilities affect decoding performance in an intracortical neural interface system

    NASA Astrophysics Data System (ADS)

    Perge, János A.; Homer, Mark L.; Malik, Wasim Q.; Cash, Sydney; Eskandar, Emad; Friehs, Gerhard; Donoghue, John P.; Hochberg, Leigh R.

    2013-06-01

    Objective. Motor neural interface systems (NIS) aim to convert neural signals into motor prosthetic or assistive device control, allowing people with paralysis to regain movement or control over their immediate environment. Effector or prosthetic control can degrade if the relationship between recorded neural signals and intended motor behavior changes. Therefore, characterizing both biological and technological sources of signal variability is important for a reliable NIS. Approach. To address the frequency and causes of neural signal variability in a spike-based NIS, we analyzed within-day fluctuations in spiking activity and action potential amplitude recorded with silicon microelectrode arrays implanted in the motor cortex of three people with tetraplegia (BrainGate pilot clinical trial, IDE). Main results. 84% of the recorded units showed a statistically significant change in apparent firing rate (3.8 ± 8.71 Hz or 49% of the mean rate) across several-minute epochs of tasks performed on a single session, and 74% of the units showed a significant change in spike amplitude (3.7 ± 6.5 µV or 5.5% of mean spike amplitude). 40% of the recording sessions showed a significant correlation in the occurrence of amplitude changes across electrodes, suggesting array micro-movement. Despite the relatively frequent amplitude changes, only 15% of the observed within-day rate changes originated from recording artifacts such as spike amplitude change or electrical noise, while 85% of the rate changes most likely emerged from physiological mechanisms. Computer simulations confirmed that systematic rate changes of individual neurons could produce a directional ‘bias’ in the decoded neural cursor movements. Instability in apparent neuronal spike rates indeed yielded a directional bias in 56% of all performance assessments in participant cursor control (n = 2 participants, 108 and 20 assessments over two years), resulting in suboptimal performance in these sessions

  17. Dyads and triads at 35,000 feet - Factors affecting group process and aircrew performance

    NASA Technical Reports Server (NTRS)

    Foushee, H. C.

    1984-01-01

    The task of flying a multipilot transport aircraft is a classic small-group performance situation where a number of social, organizational, and personality factors are relevant to important outcome variables such as safety. The aviation community is becoming increasingly aware of the importance of these factors but is hampered in its efforts to improve the system because of research psychology's problems in defining the nature of the group process. This article identifies some of the problem areas as well as methods used to address these issues. It is argued that high fidelity flight simulators provide an environment that offers unique opportunities for work meeting both basic and applied research criteria.

  18. Dyads and triads at 35,000 feet: Factors affecting group process and aircrew performance

    NASA Technical Reports Server (NTRS)

    Foushee, H. Clayton

    1987-01-01

    The task of flying a multipilot transport aircraft is a classic small-group performance situation where a number of social, organizational, and personality factors are relevant to important outcome variables such as safety. The aviation community is becoming increasingly aware of the importance of these factors but is hampered in its efforts to improve the system because of research psychology's problems in defining the nature of the group process. This article identifies some of the problem areas as well as methods used to address these issues. It is argued that high fidelity flight simulators provide an environment that offers unique opportunities for work meeting both basic and applied research criteria.

  19. Performance of fish passage structures at upstream barriers to migration

    USGS Publications Warehouse

    Bunt, C.M.; Castro-Santos, T.; Haro, A.

    2012-01-01

    Attraction and passage efficiency were reviewed and compared from 19 monitoring studies that produced data for evaluations of pool-and-weir, Denil, vertical-slot and nature-like fishways. Data from 26 species of anadromous and potamodromous fishes from six countries were separated by year and taxonomic family into a matrix with 101 records. Attraction performance was highly variable for the following fishway structures: pool-and-weir (attraction range = 29–100%, mean = 77%, median = 81%), vertical-slot (attraction range = 0–100%, mean = 63%, median = 80%), Denil (attraction range = 21–100%, mean = 61%, median = 57%) and nature-like (attraction range = 0–100%, mean = 48%, median = 50%). Mean passage efficiency was inversely related to mean attraction efficiency by fishway structure type, with the highest passage for nature-like fishways (range = 0–100%, mean = 70%, median = 86%), followed by Denil (range = 0–97%, mean = 51%, median = 38%), vertical-slot (range = 0–100%, mean = 45%, median = 43%) and pool-and-weir (range = 0–100%, mean = 40%, median = 34%). Principal components analysis and logistic regression modelling indicated that variation in fish attraction was driven by biological characteristics of the fish that were studied, whereas variation in fish passage was related to fishway type, slope and elevation change. This meta-analysis revealed that the species of fish monitored and structural design of the fishways have strong implications for both attraction and passage performance, and in most cases, existing data are not sufficient to support design recommendations. Many more fishway evaluations are needed over a range of species, fishway types and configurations to characterize, to optimize and to design new fishways. Furthermore, these studies must be performed in a consistent manner to identify the relative contributions of fish attraction and

  20. Does student learning style affect performance on different formats of biomechanics examinations?

    PubMed

    Hsieh, Chengtu; Mache, Melissa; Knudson, Duane

    2012-03-01

    Students' learning style preferences have been widely adapted into teaching and learning environments. The purpose of this study was to investigate the relationship between self-reported and assessed learning style preferences (visual, auditory, reading/writing, kinesthetic: VARK) on performance in different types of multiple-choice examinations (T1: text only format and T2: visual format) given in an introductory biomechanics class. Students who enrolled in three biomechanics classes at a state university were recruited to participate in the study. Ninety students (47 males and 43 females) completed a learning style survey and two types of examinations. Results showed that approximately half of the students were assessed and self-reported as kinesthetic for their preferred learning style. There was no significant difference in test performance between students who preferred visual and reading/writing learning styles (self-reported and assessed). These students demonstrated similar learning and comprehension of biomechanical concepts regardless of whether the test material was presented in their preferred sensory mode or not. Interestingly, female students' perceptions of their learning style preference may have a positive effect on the test results when the test is presented in their preferred format. PMID:22518949

  1. Practical factors affecting the performance of a thin-film phase plate for transmission electron microscopy

    PubMed Central

    Danev, Radostin; Glaeser, Robert M.; Nagayama, Kuniaki

    2011-01-01

    A number of practical issues must be addressed when using thin carbon films as quarter-wave plates for Zernike phase-contrast electron microscopy. We describe, for example, how we meet the more stringent requirements that must be satisfied for beam alignment in this imaging mode. In addition we address the concern that one might have regarding the loss of some of the scattered electrons as they pass through such a phase plate. We show that two easily measured parameters, (1) the low-resolution image contrast produced in cryo-EM images of tobacco mosaic virus particles and (2) the fall-off of the envelope function at high resolution, can be used to quantitatively compare the data quality for Zernike phase-contrast images and for defocused bright-field images. We describe how we prepare carbon-film phase plates that are initially free of charging or other effects that degrade image quality. We emphasize, however, that even though the buildup of hydrocarbon contamination can be avoided by heating the phase plates during use, their performance nevertheless deteriorates over the time scale of days to weeks, thus requiring their frequent replacement in order to maintain optimal performance. PMID:19157711

  2. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials

    PubMed Central

    Alburaki, Mohamed; Boutin, Sébastien; Mercier, Pierre-Luc; Loublier, Yves; Chagnon, Madeleine; Derome, Nicolas

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads. PMID:25993642

  3. Origin matters: diversity affects the performance of alien invasive species but not of native species.

    PubMed

    Sun, Yan; Müller-Schärer, Heinz; Maron, John L; Schaffner, Urs

    2015-06-01

    At local scales, it has often been found that invasibility decreases with increasing resident plant diversity. However, whether resident community diversity similarly resists invasion by alien versus native species is seldom studied. We examined this issue by invading constructed native plant assemblages that varied in species and functional richness with invasive alien or native Asteraceae species. Assemblages were also invaded with spotted knapweed, Centaurea stoebe, a native European aster that has been previously used in diversity-invasibility experiments in North America. We also conducted a field survey to explore the generality of the patterns generated from our experimental study. Both experimental and observational work revealed that increasing diversity reduced the performance of alien but not native invaders. Centaurea stoebe invading its native community performed poorly regardless of resident diversity, whereas in a parallel, previously published study conducted in North America, C. stoebe easily invaded low-diversity but not high-diversity assemblages. Our results suggest that diversity is an attribute of resident communities that makes them more or less susceptible to invasion by novel invasive alien but not native plant species. PMID:25996858

  4. How the choice of safety performance function affects the identification of important crash prediction variables.

    PubMed

    Wang, Ketong; Simandl, Jenna K; Porter, Michael D; Graettinger, Andrew J; Smith, Randy K

    2016-03-01

    Across the nation, researchers and transportation engineers are developing safety performance functions (SPFs) to predict crash rates and develop crash modification factors to improve traffic safety at roadway segments and intersections. Generalized linear models (GLMs), such as Poisson or negative binomial regression, are most commonly used to develop SPFs with annual average daily traffic as the primary roadway characteristic to predict crashes. However, while more complex to interpret, data mining models such as boosted regression trees have improved upon GLMs crash prediction performance due to their ability to handle more data characteristics, accommodate non-linearities, and include interaction effects between the characteristics. An intersection data inventory of 36 safety relevant parameters for three- and four-legged non-signalized intersections along state routes in Alabama was used to study the importance of intersection characteristics on crash rate and the interaction effects between key characteristics. Four different SPFs were investigated and compared: Poisson regression, negative binomial regression, regularized generalized linear model, and boosted regression trees. The models did not agree on which intersection characteristics were most related to the crash rate. The boosted regression tree model significantly outperformed the other models and identified several intersection characteristics as having strong interaction effects. PMID:26710265

  5. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials.

    PubMed

    Alburaki, Mohamed; Boutin, Sébastien; Mercier, Pierre-Luc; Loublier, Yves; Chagnon, Madeleine; Derome, Nicolas

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads. PMID:25993642

  6. Reindeer grazing and climate change affects vegetation structure in the Swedish mountains

    NASA Astrophysics Data System (ADS)

    Vowles, Tage; Klemendtsen, Leif; Molau, Ulf; Björk, Robert G.

    2013-04-01

    There is substantial evidence indicating that arctic and alpine landscapes are undergoing distinct changes in plant community structure, presumably brought about by increasing temperatures and a prolonged snow-free season. However, recent studies have revealed that grazing by large herbivores can inhibit a climate-driven shrub expansion and plant community change. In northern Fennoscandia reindeer grazing has helped to shape the vegetation patterns since the last glacial period and is an important factor to consider in the understanding of how a changing climate will affect tundra ecosystems. This project examines the effects of reindeer grazing by revisiting fenced exclosures constructed in 1995. The exclosures were erected at four sites with different grazing intensities situated along the Scandinavian mountain range (from 61°30' to 68°30'). At three of the four sites, three fenced and three control (ambient conditions) plots (25×25 m each) were established in alpine tundra and in mountain birch forest, respectively. In the fourth site only tundra plots were established. In 2011/12 we used the same methodology as in the original 1995 inventories to determine the species composition, canopy height, and percentage cover of the shrub, field and bottom layers in the plots. In the birch forest, the tree layer was also estimated by determining species composition, cover, height, diameter, and individual density. Our results show that on the tundra, tall shrub cover has increased at our fenced-in plots over the past 16 years, whereas in ambient plots the response varies between sites. Low shrubs, too, have increased over time, yet showing no significant treatment effect. Graminoids, on the other hand have decreased overall, but significantly more in fenced-in plots. Furthermore, the shrub canopy height has increased significantly over time with implications for albedo and snow trapping effects. Bryophyte cover was significantly larger in ambient plots than in fenced

  7. Safety and performance of adhesively bonded aluminum structures

    NASA Astrophysics Data System (ADS)

    Lu, Jianping

    The application of light-weight metallic materials (especially aluminum alloys) in tubular section shapes in the front end of automotive vehicles for crashworthiness and occupant protection is drawing considerable attention. Adhesively bonded aluminum hat sections offer light-weight solutions as energy absorbing members. Aluminum hat section, either adhesively bonded or unbonded, experiences buckling, post buckling and plastic collapse when axially loaded. The analytical solution for the critical buckling stress of the adhesively bonded aluminum hat section under static axial compression is obtained using the thin plate theory based governing partial differential equation derived by Saint Venant. The relative critical buckling stress is computed according to the transcendental equations. Finite element analyses were performed to simulate the static structural collapse, and a variety of modeling schemes are introduced. The real role of the adhesive material in the adhesively bonded hat sections in terms of energy absorption is that the adhesive does not absorb a great amount of energy by itself but shifting the buckling mode to a higher level, and hence the structure presents a higher buckling mode related buckling strength. Based on the higher buckling mode, the structure normally is not highly distorted as in the unbonded case so that the entire cross section is effectively carrying the plastic collapse load. The dynamic impact response of the adhesively bonded hat sections is explored both computationally and empirically. It is found that the finite element simulation creates satisfactory correlation to the impact test results, meanwhile, the empirical evaluation presents a quite conservative specific energy absorption.

  8. Glutaraldehyde cross-linking of amniotic membranes affects their nanofibrous structures and limbal epithelial cell culture characteristics

    PubMed Central

    Lai, Jui-Yang; Ma, David Hui-Kang

    2013-01-01

    Given that the cells can sense nanometer dimensions, the chemical cross-linking-mediated alteration in fibrillar structure of collagenous tissue scaffolds is critical to determining their cell culture performances. This article explores, for the first time, the effect of nanofibrous structure of glutaraldehyde (GTA) cross-linked amniotic membrane (AM) on limbal epithelial cell (LEC) cultivation. Results of ninhydrin assays demonstrated that the amount of new cross-links formed between the collagen chains is significantly increased with increasing the cross-linking time from 1 to 24 hours. By transmission electron microscopy, the AM treated with GTA for a longer duration exhibited a greater extent of molecular aggregation, thereby leading to a considerable increase in nanofiber diameter and resistance against collagenase degradation. In vitro biocompatibility studies showed that the samples cross-linked with GTA for 24 hours are not well-tolerated by the human corneal epithelial cell cultures. When the treatment duration is less than 6 hours, the biological tissues cross-linked with GTA for a longer time may cause slight reductions in 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt, and anti-inflammatory activities. Nevertheless, significant collagen molecular aggregation also enhances the stemness gene expression, indicating a high ability of these AM matrices to preserve the progenitors of LECs in vitro. It is concluded that GTA cross-linking of collagenous tissue materials may affect their nanofibrous structures and corneal epithelial stem cell culture characteristics. The AM treated with GTA for 6 hours holds promise for use as a niche for the expansion and transplantation of limbal epithelial progenitor cells. PMID:24204144

  9. Surface ligands affect photoinduced modulation of the quantum dots optical performance

    NASA Astrophysics Data System (ADS)

    Krivenkov, Victor A.; Samokhvalov, Pavel S.; Linkov, Pavel A.; Solovyeva, Daria O.; Kotkovskii, Gennadii E.; Chistyakov, Alexander A.; Nabiev, Igor

    2014-05-01

    Changes of optical properties of the solutions of CdSe/ZnS quantum dots (QDs) covered with the trioctylphosphine oxide (TOPO) ligands under the pulsed ultraviolet (UV) laser irradiation are observed. The fluorescence quantum yield (QY) of QDs decreases by more than an order of magnitude when the radiation dose approaches 2 × 10-15 J per particle. This process is accompanied by a blue shift of both fluorescence and the first excitonic absorption peaks. The fluorescence quenching becomes less pronounced when the overall TOPO content in the solution is increased. When ТОРО ligands are replaced with n-hexadecylamine (HDA), QY and spectral properties are not changed at the same irradiation conditions. We assume that the above changes of the optical properties are associated with photooxidation of TOPO ligands by excited QD. Such process is less probable for the HDA ligand due to its different energy structure.

  10. Optimizing Music Learning: Exploring How Blocked and Interleaved Practice Schedules Affect Advanced Performance

    PubMed Central

    Carter, Christine E.; Grahn, Jessica A.

    2016-01-01

    Repetition is the most commonly used practice strategy by musicians. Although blocks of repetition continue to be suggested in the pedagogical literature, work in the field of cognitive psychology suggests that repeated events receive less processing, thereby reducing the potential for long-term learning. Motor skill learning and sport psychology research offer an alternative. Instead of using a blocked practice schedule, with practice completed on one task before moving on to the next task, an interleaved schedule can be used, in which practice is frequently alternated between tasks. This frequent alternation involves more effortful processing, resulting in increased long-term learning. The finding that practicing in an interleaved schedule leads to better retention than practicing in a blocked schedule has been labeled the “contextual interference effect.” While the effect has been observed across a wide variety of fields, few studies have researched this phenomenon in a music-learning context, despite the broad potential for application to music practice. This study compared the effects of blocked and interleaved practice schedules on advanced clarinet performance in an ecologically valid context. Ten clarinetists were given one concerto exposition and one technical excerpt to practice in a blocked schedule (12 min per piece) and a second concerto exposition and technical excerpt to practice in an interleaved schedule (3 min per piece, alternating until a total of 12 min of practice were completed on each piece). Participants sight-read the four pieces prior to practice and performed them at the end of practice and again one day later. The sight-reading and two performance run-throughs of each piece were recorded and given to three professional clarinetists to rate using a percentage scale. Overall, whenever there was a ratings difference between the conditions, pieces practiced in the interleaved schedule were rated better than those in the blocked schedule

  11. Optimizing Music Learning: Exploring How Blocked and Interleaved Practice Schedules Affect Advanced Performance.

    PubMed

    Carter, Christine E; Grahn, Jessica A

    2016-01-01

    Repetition is the most commonly used practice strategy by musicians. Although blocks of repetition continue to be suggested in the pedagogical literature, work in the field of cognitive psychology suggests that repeated events receive less processing, thereby reducing the potential for long-term learning. Motor skill learning and sport psychology research offer an alternative. Instead of using a blocked practice schedule, with practice completed on one task before moving on to the next task, an interleaved schedule can be used, in which practice is frequently alternated between tasks. This frequent alternation involves more effortful processing, resulting in increased long-term learning. The finding that practicing in an interleaved schedule leads to better retention than practicing in a blocked schedule has been labeled the "contextual interference effect." While the effect has been observed across a wide variety of fields, few studies have researched this phenomenon in a music-learning context, despite the broad potential for application to music practice. This study compared the effects of blocked and interleaved practice schedules on advanced clarinet performance in an ecologically valid context. Ten clarinetists were given one concerto exposition and one technical excerpt to practice in a blocked schedule (12 min per piece) and a second concerto exposition and technical excerpt to practice in an interleaved schedule (3 min per piece, alternating until a total of 12 min of practice were completed on each piece). Participants sight-read the four pieces prior to practice and performed them at the end of practice and again one day later. The sight-reading and two performance run-throughs of each piece were recorded and given to three professional clarinetists to rate using a percentage scale. Overall, whenever there was a ratings difference between the conditions, pieces practiced in the interleaved schedule were rated better than those in the blocked schedule

  12. Different effects of economic and structural performance indexes on model construction of structural topology optimization

    NASA Astrophysics Data System (ADS)

    Yi, G. L.; Sui, Y. K.

    2015-10-01

    The objective and constraint functions related to structural optimization designs are classified into economic and performance indexes in this paper. The influences of their different roles in model construction of structural topology optimization are also discussed. Furthermore, two structural topology optimization models, optimizing a performance index under the limitation of an economic index, represented by the minimum compliance with a volume constraint (MCVC) model, and optimizing an economic index under the limitation of a performance index, represented by the minimum weight with a displacement constraint (MWDC) model, are presented. Based on a comparison of numerical example results, the conclusions can be summarized as follows: (1) under the same external loading and displacement performance conditions, the results of the MWDC model are almost equal to those of the MCVC model; (2) the MWDC model overcomes the difficulties and shortcomings of the MCVC model; this makes the MWDC model more feasible in model construction; (3) constructing a model of minimizing an economic index under the limitations of performance indexes is better at meeting the needs of practical engineering problems and completely satisfies safety and economic requirements in mechanical engineering, which have remained unchanged since the early days of mechanical engineering.

  13. Characterization and estimation of permeability correlation structure from performance data

    SciTech Connect

    Ershaghi, I.; Al-Qahtani, M.

    1997-08-01

    In this study, the influence of permeability structure and correlation length on the system effective permeability and recovery factors of 2-D cross-sectional reservoir models, under waterflood, is investigated. Reservoirs with identical statistical representation of permeability attributes are shown to exhibit different system effective permeability and production characteristics which can be expressed by a mean and variance. The mean and variance are shown to be significantly influenced by the correlation length. Detailed quantification of the influence of horizontal and vertical correlation lengths for different permeability distributions is presented. The effect of capillary pressure, P{sub c1} on the production characteristics and saturation profiles at different correlation lengths is also investigated. It is observed that neglecting P{sub c} causes considerable error at large horizontal and short vertical correlation lengths. The effect of using constant as opposed to variable relative permeability attributes is also investigated at different correlation lengths. Next we studied the influence of correlation anisotropy in 2-D reservoir models. For a reservoir under five-spot waterflood pattern, it is shown that the ratios of breakthrough times and recovery factors of the wells in each direction of correlation are greatly influenced by the degree of anisotropy. In fully developed fields, performance data can aid in the recognition of reservoir anisotropy. Finally, a procedure for estimating the spatial correlation length from performance data is presented. Both the production performance data and the system`s effective permeability are required in estimating the correlation length.

  14. How Has the Affordable Care Act Affected Health Insurers' Financial Performance?

    PubMed

    Hall, Mark A; McCue, Michael J

    2016-07-01

    Starting in 2014, the Affordable Care Act transformed the market for individual health insurance by changing how insurance is sold and by subsidizing coverage for millions of new purchasers. Insurers, who had no previous experience under these market conditions, competed actively but faced uncertainty in how to price their products. This issue brief uses newly available data to understand how health insurers fared financially during the ACA's first year of full reforms. Overall, health insurers' financial performance began to show some strain in 2014, but the ACA's reinsurance program substantially buffered the negative effects for most insurers. Although a quarter of insurers did substantially worse than others, experience under the new market rules could improve the accuracy of pricing decisions in subsequent years. PMID:27459740

  15. Orientation in the wandering albatross: interfering with magnetic perception does not affect orientation performance.

    PubMed

    Bonadonna, F; Bajzak, C; Benhamou, S; Igloi, K; Jouventin, P; Lipp, H P; Dell'Omo, G

    2005-03-01

    After making foraging flights of several thousands of kilometers, wandering albatrosses (Diomedea exulans) are able to pinpoint a specific remote island where their nests are located. This impressive navigation ability is highly precise but its nature is mysterious. Here we examined whether albatrosses rely on the perception of the Earth's magnetic field to accomplish this task. We disturbed the perception of the magnetic field using mobile magnets glued to the head of nine albatrosses and compared their performances with those of 11 control birds. We then used satellite telemetry to monitor their behavior. We found that the ability of birds to home specific nest sites was unimpaired by this manipulation. In particular, experimental and control birds did not show significant differences with respect to either foraging trip duration, or length, or with respect to homing straightness index. Our data suggest that wandering albatrosses do not require magnetic cues to navigate back to their nesting birds. PMID:15799944

  16. Numerical analysis of the performance of rock weirs: Effects of structure configuration on local hydraulics

    USGS Publications Warehouse

    Holmquist-Johnson, C. L.

    2009-01-01

    River spanning rock structures are being constructed for water delivery as well as to enable fish passage at barriers and provide or improve the aquatic habitat for endangered fish species. Current design methods are based upon anecdotal information applicable to a narrow range of channel conditions. The complex flow patterns and performance of rock weirs is not well understood. Without accurate understanding of their hydraulics, designers cannot address the failure mechanisms of these structures. Flow characteristics such as jets, near bed velocities, recirculation, eddies, and plunging flow govern scour pool development. These detailed flow patterns can be replicated using a 3D numerical model. Numerical studies inexpensively simulate a large number of cases resulting in an increased range of applicability in order to develop design tools and predictive capability for analysis and design. The analysis and results of the numerical modeling, laboratory modeling, and field data provide a process-based method for understanding how structure geometry affects flow characteristics, scour development, fish passage, water delivery, and overall structure stability. Results of the numerical modeling allow designers to utilize results of the analysis to determine the appropriate geometry for generating desirable flow parameters. The end product of this research will develop tools and guidelines for more robust structure design or retrofits based upon predictable engineering and hydraulic performance criteria. ?? 2009 ASCE.

  17. Does Increasing Active Warm-Up Duration Affect Afternoon Short-Term Maximal Performance during Ramadan?

    PubMed Central

    Baklouti, Hana; Aloui, Asma; Chtourou, Hamdi; Briki, Walid; Chaouachi, Anis; Souissi, Nizar

    2015-01-01

    Aim The purpose of this study was to examine the effect of active warm-up duration on short-term maximal performance assessed during Ramadan in the afternoon. Methods Twelve healthy active men took part in the study. The experimental design consisted of four test sessions conducted at 5 p.m., before and during Ramadan, either with a 5-minute or a 15-minute warm-up. The warm-up consisted in pedaling at 50% of the power output obtained at the last stage of a submaximal multistage cycling test. During each session, the subjects performed two vertical jump tests (squat jump and counter movement jump) for measurement of vertical jump height followed by a 30-second Wingate test for measurement of peak and mean power. Oral temperature was recorded at rest and after warming-up. Moreover, ratings of perceived exertion were obtained immediately after the Wingate test. Results Oral temperature was higher before Ramadan than during Ramadan at rest, and was higher after the 15-minute warm-up than the 5-minute warm-up both before and during Ramadan. In addition, vertical jump heights were not significantly different between the two warm-up conditions before and during Ramadan, and were lower during Ramadan than before Ramadan after both warm-up conditions. Peak and mean power were not significantly different between the two warm-up durations before Ramadan, but were significantly higher after the 5-minute warm-up than the 15-minute warm-up during Ramadan. Moreover, peak and mean power were lower during Ramadan than before Ramadan after both warm-up conditions. Furthermore, ratings of perceived exertion were higher after the 15-minute warm-up than the 5-minute warm-up only during Ramadan. Conclusion The prolonged active warm-up has no effect on vertical jump height but impairs anaerobic power assessed during Ramadan in the afternoon. PMID:25646955

  18. Indian Bt Cotton Varieties Do Not Affect the Performance of Cotton Aphids

    PubMed Central

    Lawo, Nora C.; Wäckers, Felix L.; Romeis, Jörg

    2009-01-01

    Cotton varieties expressing Cry proteins derived from the soil bacterium Bacillus thuringiensis (Bt) are grown worldwide for the management of pest Lepidoptera. To prevent non-target pest outbreaks and to retain the biological control function provided by predators and parasitoids, the potential risk that Bt crops may pose to non-target arthropods is addressed prior to their commercialization. Aphids play an important role in agricultural systems since they serve as prey or host to a number of predators and parasitoids and their honeydew is an important energy source for several arthropods. To explore possible indirect effects of Bt crops we here examined the impact of Bt cotton on aphids and their honeydew. In climate chambers we assessed the performance of cotton aphids, Aphis gossypii Glover (Hemiptera: Aphididae) when grown on three Indian Bt (Cry1Ac) cotton varieties (MECH 12, MECH 162, MECH 184) and their non-transformed near isolines. Furthermore, we examined whether aphids pick up the Bt protein and analyzed the sugar composition of aphid honeydew to evaluate its suitability for honeydew-feeders. Plant transformation did not have any influence on aphid performance. However, some variation was observed among the three cotton varieties which might partly be explained by the variation in trichome density. None of the aphid samples contained Bt protein. As a consequence, natural enemies that feed on aphids are not exposed to the Cry protein. A significant difference in the sugar composition of aphid honeydew was detected among cotton varieties as well as between transformed and non-transformed plants. However, it is questionable if this variation is of ecological relevance, especially as honeydew is not the only sugar source parasitoids feed on in cotton fields. Our study allows the conclusion that Bt cotton poses a negligible risk for aphid antagonists and that aphids should remain under natural control in Bt cotton fields. PMID:19279684

  19. Injection Temperature Significantly Affects In Vitro and In Vivo Performance of Collagen-Platelet Scaffolds

    PubMed Central

    Palmer, M.P.; Abreu, E.L.; Mastrangelo, A.; Murray, M.M.

    2009-01-01

    Collagen-platelet composites have recently been successfully used as scaffolds to stimulate anterior cruciate ligament (ACL) wound healing in large animal models. These materials are typically kept on ice until use to prevent premature gelation; however, with surgical use, placement of a cold solution then requires up to an hour while the solution comes to body temperature (at which point gelation occurs). Bringing the solution to a higher temperature before injection would likely decrease this intra-operative wait; however, the effects of this on composite performance are not known. The hypothesis tested here was that increasing the temperature of the gel at the time of injection would significantly decrease the time to gelation, but would not significantly alter the mechanical properties of the composite or its ability to support functional tissue repair. Primary outcome measures included the maximum elastic modulus (stiffness) of the composite in vitro and the in vivo yield load of an ACL transection treated with an injected collagen-platelet composite. In vitro findings were that injection temperatures over 30°C resulted in a faster visco-elastic transition; however, the warmed composites had a 50% decrease in their maximum elastic modulus. In vivo studies found that warming the gels prior to injection also resulted in a decrease in the yield load of the healing ACL at 14 weeks. These studies suggest that increasing injection temperature of collagen-platelet composites results in a decrease in performance of the composite in vitro and in the strength of the healing ligament in vivo and this technique should be used only with great caution. PMID:19030174

  20. Flow structures in submarine channels affected by Coriolis forces: Experimental observations

    NASA Astrophysics Data System (ADS)

    Cossu, R.; Wells, M. G.

    2011-12-01

    In this talk we will show how Coriolis forces can control the flow dynamics of turbidity currents flowing in sinuous channels at high latitudes. We describe how the internal velocity structure changes with latitude, based on observations from rotating laboratory experiments. When these results are combined with existing conceptual facies and depositional models we can now describe the changes in sedimentation patterns that are observed at different latitudes. The experiments were conducted in a sinuous channel model placed in a tank that was rotated at various rates (reflected by the Coriolis parameters f) ranging from f = 0 (at the equator) to ± 0.5 rad s-1 (at higher latitudes). The dependence of the density interface of gravity currents on rotation is shown in Figure 1a. At the equator the interface slopes up to the outer bend due to the centrifugal forces. In the Northern Hemisphere (NH) the tilt of the interface increases as now the Coriolis forces reinforce the centrifugal acceleration. In contrast, in the Southern Hemisphere (SH) the current ramps up to the inner bend and Coriolis forces dominate over centrifugal forces. Figure 1b shows the corresponding position of the downstream velocity core in the bend apex. At the equator the core is predominantly close to the centerline, whilst in the NH the core is deflected to the inner bend and in the SH the velocity core is shifted to the outer bank. Based upon our experimental results, we hypothesize that Coriolis forces can affect the velocity structure and sedimentation regime. Lateral accretion packages (LAPs) are built only on one side in the channel and finer sediments will be deposited mainly on the levee bank to which the high velocity core is deflected. The Rossby number RoW = U/fW (where U is the mean downstream velocity and W the channel width) can be used to determine the influence of Coriolis forces. In channel systems at high-latitudes (with RoW << 1) we predict that channels exhibit a low sinuosity

  1. Factors affecting the stability and performance of ionic liquid-based planar transient photodetectors.

    PubMed

    Dalgleish, Simon; Reissig, Louisa; Hu, Laigui; Matsushita, Michio M; Sudo, Yuki; Awaga, Kunio

    2015-05-12

    A novel planar architecture has been developed for the study of photodetectors utilizing the transient photocurrent response induced by a metal/insulator/semiconductor/metal (MISM) structured device, where the insulator is an ionic liquid (IL-MISM). Using vanadyl 2,3-naphthalocyanine, which absorbs in the communications-relevant near-infrared wavelength region (λ(max,film) ≈ 850 nm), in conjunction with C60 as a bulk heterojunction, the high capacitance of the formed electric double layers at the ionic liquid interfaces yields high charge separation efficiency within the semiconductor layer, and the minimal potential drop in the bulk ionic liquid allows the electrodes to be offset by distances of over 7 mm. Furthermore, the decrease in operational speed with increased electrode separation is beneficial for a clear modeling of the waveform of the photocurrent signal, free from the influence of measurement circuitry. Despite the use of a molecular semiconductor as the active layer in conjunction with a liquid insulating layer, devices with a stability of several days could be achieved, and the operational stability of such devices was shown to be dependent solely on the solubility of the active layer in the ionic liquid, even under atmospheric conditions. Furthermore, the greatly simplified device construction process, which does not rely on transparent electrode materials or direct electrode deposition, provides a highly reproducible platform for the study of the electronic processes within IL-MISM detectors that is largely free from architectural constraints. PMID:25895167

  2. Can intra-aggregate pore structures affect the aggregate's effectiveness in protecting carbon?

    SciTech Connect

    Ananyeva, K; Wang, W; Smucker, A J.M.; Rivers, M L; Kravchenko, A N

    2012-11-15

    Aggregates are known to provide physical protection to soil organic matter shielding it from rapid decomposition. Spatial arrangement and size distribution of intra-aggregate pores play an important role in this process. This study examined relationships between intra-aggregate pores measured using X-ray computed micro-tomography images and concentrations of total C in 4–6 mm macro-aggregates from two contrasting land use and management practices, namely, conventionally tilled and managed row crop agricultural system (CT) and native succession vegetation converted from tilled agricultural land in 1989 (NS). Previous analyses of these aggregates indicated that small (<15 μm) and large (>100 μm) pores prevail in NS aggregates while medium (30–90 μm) pores are more abundant in CT aggregates (Kravchenko et al., 2011; Wang et al., 2012). We hypothesized that these differences in pore size distributions affect the ability of macro-aggregates to protect C. The results of this study supported this hypothesis. Consistent with greater heterogeneity of pore distributions within NS aggregates we observed higher total C and greater intra-aggregate C variability in NS as compared with CT aggregates. Total C concentrations and intra-aggregate C standard deviations were negatively correlated with fractions of medium sized pores, indicating that presence of such pores was associated with lower but more homogeneously distributed total C. While total C was positively correlated with presence of small and large pores. The results suggest that because of their pore structure NS macro-aggregates provide more effective physical protection to C than CT aggregates.

  3. The use of anti-asthmatic drugs. Do they affect sports performance?

    PubMed

    Fitch, K D

    1986-01-01

    Recent major advances in pharmacological management have provided asthmatics with a satisfactory range of drugs to control asthma. These include sodium cromoglycate (cromolyn sodium), H1-antagonists, belladonna alkaloids, methyl xanthines, glucocorticoids and beta 2-adrenoceptor stimulants. Despite the tendency for most asthmatics to develop bronchoconstriction after exercise, sport and physical activity are now accepted as valuable in the overall management of patients with asthma. Thus, control of exercise-induced asthma (EIA) is essential, if asthmatics are to participate safely in physical activity and without respiratory disadvantage in competitive sport. Fortunately, inhibition or minimization of exercise-induced asthma may be achieved in most asthmatics by pre-exercise aerosol beta 2-agonists supplemented if necessary by sodium cromoglycate and/or theophylline. Regular medication as required to attain and maintain normal ventilatory function throughout each day is the objective in all patients with asthma and appears to be a prerequisiste to control exercise-induced asthma. The introduction of anti-doping controls into high performance sport has presented added difficulties for the asthmatic athlete. Although not always so, currently all of the classes of drugs previously noted are acceptable for the treatment of asthma and exercise-induced asthma. Anomalies may exist in the banning of 2 beta 2-adrenoceptor agonists, fenoterol and orciprenaline (metaproterenol). All sympathomimetic amines with alpha- or predominantly beta-stimulation are banned. The perpetuation of the need to report the use of beta 2-agonists prior to competition appears unnecessary. Although relatively little specific research has been undertaken, there is minimal evidence to suggest that asthmatics can derive any additional ergogenic advantage from medication to control asthma and exercise-induced asthma. beta 2-agonists, sodium cromoglycate and glucocorticoids administered by the aerosol

  4. Topographic changes detection through Structure-from-Motion in agricultural lands affected by erosion processes

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Pradetto Sordo, Nicoletta; Burguet, Maria; Di Prima, Simone; Terol Esparza, Enric; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Throughout the world, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas (Cerdà et al., 2009; Cerdan et al., 2010; García-Ruiz, 2010). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as land-use changes on large scales and unsustainable farming practices (Boardman et al., 1990; Cerdà 1994; Montgomery, 2007). Tillage operations, combined with weather conditions, are recognized to primarily influence soil erosion rates. If, on one hand, tillage operations cause uniform changes based on the tool used, on the other, weather conditions, such as rainfalls, produce more random changes, less easily traceable (Snapir et al., 2014). Within this context, remote-sensing technologies can facilitate the detection and quantification of these topographic changes. In particular, a real opportunity and challenge is offered by the low-cost and flexible photogrammetric technique, called 'Structure-from-Motion' (SfM), combined with the use of smartphones (Micheletti et al., 2014; Prosdocimi et al., 2015). This represents a significant advance compared with more expensive technologies and applications (e.g. Terrestrial Laser Scanner - TLS) (Tarolli, 2014). This work wants to test the Structure from Motion to obtain high-resolution topography for the detection of topographic changes in agricultural lands affected by erosion processes. Two case studies were selected: i) a tilled plot characterized by bare soil and affected by rill erosion located in the hilly countryside of Marche region (central Italy), and ii) a Mediterranean vineyard located within the province of Valencia (south eastern Spain) where rainfall simulation experiments were carried out. Extensive photosets were obtained by using one standalone reflex digital camera and one smartphone built-in digital camera. Digital

  5. Motor abilities in dance structure performance in female students.

    PubMed

    Srhoj, Ljerka; Katić, Ratko; Kaliterna, Andreja

    2006-06-01

    The aim of the study was to analyze the relation between motor abilities and performance in folk dances originating from the island of Hvar and modern social dances. Two groups of variables were used in a sample of 78 female students of the Teacher Training College from Split: 7 motor variables as a battery of predictors, and performance evaluation of 4 dances (2 folk dances, i.e. ciciliona and pasavijen, and 2 social dances, i.e. cha-cha-cha and rock-'n'-roll) as criterion variables. Canonical correlation analysis between the groups of variables yielded two canonical correlations of 0.94 and 0.73, with a level of significance of p<0.001. The first canonical correlation was based on marked determination of coordination and ciciliona dance, and the second one on explosive strength of the running type with below-average coordination and the cha-cha-cha, rock-'n'-roll and pasavijen dances. Regression analysis indicated the battery of motor variables used to be a good predictor of performance in all study dances, with multiple correlation of 0.93 in ciciliona, 0.84 in pasavijen, 0.75 in rock-'n'-roll and 0.73 in cha-cha-cha. In ciciliona and pasavijen, the latent dance structure is predominantly explained by coordination, in rock-'n'-roll by explosive strength, and in cha-cha-cha by explosive strength and speed. Discriminative analysis revealed the general dance performance to mostly depend on coordination, then on explosive strength, and to a lesser extent on speed (movement frequency). Dance is an irreplaceable educational tool in kinesiologic education of female students, among others for its considerable contribution to the development and maintenance of basic motor abilities. PMID:16848148

  6. Decreased Core Crystallinity Facilitated Drug Loading in Polymeric Micelles without Affecting Their Biological Performances.

    PubMed

    Gou, Jingxin; Feng, Shuangshuang; Xu, Helin; Fang, Guihua; Chao, Yanhui; Zhang, Yu; Xu, Hui; Tang, Xing

    2015-09-14

    Cargo-loading capacity of polymeric micelles could be improved by reducing the core crystallinity and the improvement in the amount of loaded cargo was cargo-polymer affinity dependent. The effect of medium chain triglyceride (MCT) in inhibiting PCL crystallization was confirmed by DSC and polarized microscope. When incorporating MCT into polymeric micelles, the maximum drug loading of disulfiram (DSF), cabazitaxel (CTX), and TM-2 (a taxane derivative) increased from 2.61 ± 0.100%, 13.5 ± 0.316%, and 20.9 ± 1.57% to 8.34 ± 0.197%, 21.7 ± 0.951%, and 28.0 ± 1.47%, respectively. Moreover, the prepared oil-containing micelles (OCMs) showed well-controlled particle size, good stability, and decreased drug release rate. MCT incorporation showed little influence on the performances of micelles in cell studies or pharmacokinetics. These results indicated that MCT incorporation could be a core construction module applied in the delivery of hydrophobic drugs. PMID:26314832

  7. Contrasting the grain boundary-affected performance of zinc and indium oxide transparent conductors.

    PubMed

    Vai, A T; Rashidi, N; Fang, Y; Kuznetsov, V L; Edwards, P P

    2016-06-01

    Zinc oxide-based transparent conductors have long been advanced for their potential as low-cost, earth-abundant replacements for the indium oxide-based materials that currently dominate in practical applications. However, this potential has yet to be realized because of the difficulties in producing zinc oxide thin films with the necessary high levels of electrical conductivity and environmental stability that are readily achieved using indium oxide. To better understand the fundamental reasons for this, polycrystalline zinc and indium oxide thin films were prepared across a range of deposition temperatures using the technique of spray pyrolysis. Electrical transport measurements of these samples both as a function of temperature and UV irradiation were correlated with film morphology to illustrate that the different grain boundary behaviour of these two materials is one of the key reasons for their divergent performance. This is a critical challenge that must be addressed before any substantial increase in the adoption of ZnO-based transparent conductors can take place. PMID:26952740

  8. Contrasting the grain boundary-affected performance of zinc and indium oxide transparent conductors

    NASA Astrophysics Data System (ADS)

    Vai, A. T.; Rashidi, N.; Fang, Y.; Kuznetsov, V. L.; Edwards, P. P.

    2016-06-01

    Zinc oxide-based transparent conductors have long been advanced for their potential as low-cost, earth-abundant replacements for the indium oxide-based materials that currently dominate in practical applications. However, this potential has yet to be realized because of the difficulties in producing zinc oxide thin films with the necessary high levels of electrical conductivity and environmental stability that are readily achieved using indium oxide. To better understand the fundamental reasons for this, polycrystalline zinc and indium oxide thin films were prepared across a range of deposition temperatures using the technique of spray pyrolysis. Electrical transport measurements of these samples both as a function of temperature and UV irradiation were correlated with film morphology to illustrate that the different grain boundary behaviour of these two materials is one of the key reasons for their divergent performance. This is a critical challenge that must be addressed before any substantial increase in the adoption of ZnO-based transparent conductors can take place.

  9. Speaking, writing, and memory span in children: output modality affects cognitive performance.

    PubMed

    Grabowski, Joachim

    2010-02-01

    Low-level processes of children's written language production are cognitively more costly than those involved in speaking. This has been shown by French authors who compared oral and written memory span performance. The observed difficulties of children's, but not of adults' low-level processes in writing may stem from graphomotoric as well as from orthographic inadequacies. We report on five experiments designed to replicate and expand the original results. First, the French results were successfully replicated for German third-graders, and for university students. Then, the developmental changes of the cognitive costs of writing were examined during primary school, comparing the performance of second- and fourth-graders. Next, we show that unpractised writing modes, which were experimentally induced, also lead to a decrease of memory performance in adults, which supports the assumption that a lack of graphomotoric automation is responsible for the observed effects in children. However, unpractised handwriting yields clearer results than unpractised typing. Lastly, we try to separate the influences of graphomotoric as opposed to orthographic difficulties by having the words composed through pointing on a "spelling board". This attempt, however, has not been successful, probably because the pointing to letters introduced other low-level costs. In sum, throughout the four years of primary school, German children show worse memory span performance in writing compared to oral recall, with an overall increase in both modalities. Thus, writing had not fully caught up with speaking regarding the implied cognitive costs by the end of primary school. Therefore, conclusions relate to the question of how to assess properly any kind of knowledge and abilities through language production. Los procesos de bajo nivel en la producción de lenguaje escrito en niños son más costosos a nivel cognitivo que los que están implicados en el habla. Esto ha sido demostrado por autores

  10. Factors that affect the hydraulic performance of raingardens: implications for design and maintenance.

    PubMed

    Virahsawmy, Harry K; Stewardson, Michael J; Vietz, Geoff; Fletcher, Tim D

    2014-01-01

    Raingardens are becoming an increasingly popular technology for urban stormwater treatment. However, their hydraulic performance is known to reduce due to clogging from deposition of fine-grained sediments on the surface. This impacts on their capacity to treat urban runoff. It has been recently hypothesised that plants can help to mitigate the effect of surface clogging on infiltration. A conceptual model is therefore presented to better understand key processes, including those associated with plant cover, which influences surface infiltration mechanisms. Based on this understanding, a field evaluation was carried out to test the hypothesis that plants increase the infiltration rate, and to investigate factors that influence the deposition of fine-grained sediments within raingardens. The results show that infiltration rates around plants are statistically higher than bare areas, irrespective of the degree of surface clogging. This suggests that preferential flow pathways exist around plants. Sediment deposition processes are also influenced by design elements of raingardens such as the inlet configuration. These findings have implications for the design and maintenance of raingardens, in particular the design of the inlet configuration, as well as maintenance of the filter media surface layer and vegetation. PMID:24622546

  11. Dietary Probiotics Affect Gastrointestinal Microbiota, Histological Structure and Shell Mineralization in Turtles.

    PubMed

    Rawski, Mateusz; Kierończyk, Bartosz; Długosz, Jakub; Świątkiewicz, Sylwester; Józefiak, Damian

    2016-01-01

    Probiotics are widely used in nutrition, and their mode of action is intensively studied in mammals and birds; however, it is almost unknown in reptiles. In the present study, Trachemys scripta scripta and Sternotherus odoratus were used to assess the effects of dietary probiotics on chelonian gastrointestinal tract microecology. In the first, 20-week experiment, 40 young T. s. scripta were randomly distributed to four experimental groups: 1st, (CON)--with no additives; 2nd, (SSPA) with Bacillus subtilis PB6; 3rd, (MSP)--with multiple strain probiotic; and 4th, (SSPB) with Bacillus subtilis C-3102. The first study has shown that SSPA and MSP decreased the numbers of total bacteria, Enterobacteriace, Staphylococcus sp. and Streptococcus sp. excreted to water and increased the villous height and mucosa thickness in duodenum. SSPB improved the duodenal microstructure; however, it also increased numbers of kanamycin and vancomycin resistant bacteria, Staphylococcus sp. and Streptococcus sp., in water. In the second, 52-week experiment, 30 S. odoratus were randomly assigned to three dietary treatments. CON, SSPA and MSP groups. The MSP preparation increased the body weight gain, crude ash, Ca and P share in the turtles' shells. Both probiotics affected duodenal histomorphology. SSPA decreased the villous height, while MSP increased the villous height and mucosa thickness, and decreased the crypt depth. SSPA decreased the concentrations of bacteria excreted to water. In the case of intestinal microbiota, bacteria suppressing effects were observed in the case of both probiotics. MSP increased the number of Bifidobacterium sp. and Lactobacillus sp./Enteroccoccus sp., and decreased the number of Clostridium perfringens and Campylobacter sp. in the small intestine. In the large intestine it lowered, amongst others, Bacteroides-Pervotella cluster, Clostridium leptum subgroup and Clostridium perfringens numbers. The above-mentioned results suggest that probiotics are useful in

  12. Dietary Probiotics Affect Gastrointestinal Microbiota, Histological Structure and Shell Mineralization in Turtles

    PubMed Central

    Rawski, Mateusz; Kierończyk, Bartosz; Długosz, Jakub; Świątkiewicz, Sylwester; Józefiak, Damian

    2016-01-01

    Probiotics are widely used in nutrition, and their mode of action is intensively studied in mammals and birds; however, it is almost unknown in reptiles. In the present study, Trachemys scripta scripta and Sternotherus odoratus were used to assess the effects of dietary probiotics on chelonian gastrointestinal tract microecology. In the first, 20-week experiment, 40 young T. s. scripta were randomly distributed to four experimental groups: 1st, (CON)–with no additives; 2nd, (SSPA) with Bacillus subtilis PB6; 3rd, (MSP)–with multiple strain probiotic; and 4th, (SSPB) with Bacillus subtilis C-3102. The first study has shown that SSPA and MSP decreased the numbers of total bacteria, Enterobacteriace, Staphylococcus sp. and Streptococcus sp. excreted to water and increased the villous height and mucosa thickness in duodenum. SSPB improved the duodenal microstructure; however, it also increased numbers of kanamycin and vancomycin resistant bacteria, Staphylococcus sp. and Streptococcus sp., in water. In the second, 52-week experiment, 30 S. odoratus were randomly assigned to three dietary treatments. CON, SSPA and MSP groups. The MSP preparation increased the body weight gain, crude ash, Ca and P share in the turtles’ shells. Both probiotics affected duodenal histomorphology. SSPA decreased the villous height, while MSP increased the villous height and mucosa thickness, and decreased the crypt depth. SSPA decreased the concentrations of bacteria excreted to water. In the case of intestinal microbiota, bacteria suppressing effects were observed in the case of both probiotics. MSP increased the number of Bifidobacterium sp. and Lactobacillus sp./Enteroccoccus sp., and decreased the number of Clostridium perfringens and Campylobacter sp. in the small intestine. In the large intestine it lowered, amongst others, Bacteroides–Pervotella cluster, Clostridium leptum subgroup and Clostridium perfringens numbers. The above-mentioned results suggest that probiotics are

  13. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    PubMed Central

    Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

    2016-01-01

    Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions. PMID:26735689

  14. Four Human Thiopurine S-Methyltransferase Alleles Severely Affect Protein Structure and Dynamics

    PubMed Central

    Rutherford, Karen; Daggett, Valerie

    2008-01-01

    Summary Thiopurine S-methyltransferase (TPMT) metabolizes cytotoxic thiopurine drugs used in the treatment of leukemia and inflammatory bowel disease. TPMT is a major pharmacogenomic target with 23 alleles identified to date. Several of these alleles cause rapid protein degradation and/or aggregation, making it extremely difficult to study the structural impact of the TPMT polymorphisms experimentally. We, therefore, have performed multiple molecular dynamics simulations of the four most common alleles (TPMT 2 (A80P), 3A (A154T/Y240C), 3B (A154T) and 3C (Y240C)) to investigate the molecular mechanism of TPMT inactivation at an atomic level. The A80P polymorphism in TPMT *2 disrupts helix α3 bordering the active site, which breaks several salt-bridge interactions and opens up a large cleft in the protein. The A154T polymorphism is located within the co-substrate binding-site. The larger threonine alters the packing of substrate binding residues (P68, L69, Y166), increasing the solvent exposure of the polymorphic site. This packing rearrangement may account for the complete lack of activity in the A154T mutant. The Y240C polymorphism is located in β-strand 9, distant from the active site. Side-chain contacts between residue 240 and helix α8 are lost in TPMT *3C. Residues 154 and 240 in TPMT *3A are connected through a hydrogen-bonding network. The dual polymorphisms result in a flattened, slightly distorted protein structure and an increase in the thiopurine-binding site solvent accessibility. The two variants that undergo the most rapid degradation in vivo, TPMT*2 and *3A, are also the most deformed in the simulations. PMID:18482735

  15. Factors affecting brain structure in men with HIV disease in the post-HAART era

    PubMed Central

    Maruca, Victoria; Kingsley, Lawrence A.; Sanders, Joanne M.; Alger, Jeffery R.; Barker, Peter B.; Goodkin, Karl; Martin, Eileen; Miller, Eric N.; Ragin, Ann; Sacktor, Ned; Selnes, Ola

    2011-01-01

    Introduction The purpose of this study was to characterize brain volumetric differences in HIV seropositive and seronegative men and to determine effects of age, cardiovascular risk, and HIV infection on structural integrity. Methods Magnetic resonance imaging was used to acquire high-resolution neuroanatomic data in 160 men aged 50 years and over, including 84 HIV seropositive and 76 seronegative controls. Voxel-based morphometry was used to derive volumetric measurements at the level of the individual voxel. Data from a detailed neuropsychological test battery were recombined into four summary scores representing psychomotor speed, visual memory, verbal memory, and verbal fluency. Results Both age and HIV status had a significant effect on both gray matter (GM) and white matter (WM) volume. The age-related GM atrophy was primarily in the superior temporal and inferior frontal regions; the HIV-related GM loss included the posterior and inferior temporal lobes, the parietal lobes, and the cerebellum. Among all subjects, the performance on neuropsychological tests, as indexed by a summary variable, was related to the volume of both the GM and WM. Contrary to our predictions, the CVD variables were not linked to brain volume in statistically adjusted models. Conclusion In the post-HAART era, having HIV infection is still linked to atrophy in both GM and WM. Secondly, advancing age, even in this relatively young cohort, is also linked to changes in GM and WM volume. Thirdly, CNS structural integrity is associated with overall cognitive functions, regardless of the HIV infection status of the study volunteers. PMID:21424708

  16. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest.

    PubMed

    Sun, Hui; Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O

    2016-05-01

    Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P< 0.001) and tree species (P< 0.001). The distance-based linear models analysis showed that environmental variables were significantly correlated with community structure (P< 0.04). The availability of soil nutrients (Ca [P= 0.002], Fe [P= 0.003], and P [P= 0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P< 0.004). The results of the molecular identification were supplemented by fruiting body surveys. Seven of the genera ofAgaricomycotinaidentified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. PMID:26896139

  17. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1995-05-09

    A high performance capacitor is fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a ``notepad`` configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The notepad capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density. 5 figs.

  18. An advanced probabilistic structural analysis method for implicit performance functions

    NASA Technical Reports Server (NTRS)

    Wu, Y.-T.; Millwater, H. R.; Cruse, T. A.

    1989-01-01

    In probabilistic structural analysis, the performance or response functions usually are implicitly defined and must be solved by numerical analysis methods such as finite element methods. In such cases, the most commonly used probabilistic analysis tool is the mean-based, second-moment method which provides only the first two statistical moments. This paper presents a generalized advanced mean value (AMV) method which is capable of establishing the distributions to provide additional information for reliability design. The method requires slightly more computations than the second-moment method but is highly efficient relative to the other alternative methods. In particular, the examples show that the AMV method can be used to solve problems involving non-monotonic functions that result in truncated distributions.

  19. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1996-01-23

    A high performance capacitor is described which is fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a ``notepad`` configuration composed of 200--300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The ``notepad`` capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density. 5 figs.

  20. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, Jr., Troy W.; Johnson, Gary W.; O'Brien, Dennis W.

    1995-01-01

    A high performance capacitor fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a "notepad" configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The "notepad" capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density.

  1. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, Jr., Troy W.; Johnson, Gary W.; O'Brien, Dennis W.

    1996-01-01

    A high performance capacitor fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a "notepad" configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The "notepad" capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density.

  2. High-performance semiactive controller for structural vibration suppression

    NASA Astrophysics Data System (ADS)

    Bobrow, James E.; Jabbari, Faryar

    1997-06-01

    This article presents an approach to vibration suppression that does not use a viscous damper. The actuator used behaves effectively as a spring with an adjustable unstressed length. By adjusting this unstressed length on-line from feedback, it is possible to obtain fast settling times and superior shock isolation characteristics. At the instants when energy in the actuator is maximized, we discard this energy as heat in the working fluid by opening a low power solenoid valve for a short time interval. This sets the unstressed length of the actuator, or effective spring, to be zero. The total energy in the vibrating structure is therefore decreased at these instants of unstressed length adjustment. Analytical results and simulations are given that demonstrate the performance of our approach.

  3. The Effect of Nitrogen Deposition on Plant Performance and Community Structure: Is It Life Stage Specific?

    PubMed

    Tulloss, Elise M; Cadenasso, Mary L

    2016-01-01

    Nitrogen (N) deposition is a key global change factor that is increasing and affecting the structure and function of many ecosystems. To determine the influence of N deposition on specific systems, however, it is crucial to understand the temporal and spatial patterns of deposition as well as the response to that deposition. Response of the receiving plant communities may depend on the life stage-specific performance of individual species. We focus on the California oak savanna because N deposition to this system is complex-characterized by hotspots on the landscape and seasonal pulses. In a greenhouse experiment, we investigated the relative influence of N deposition on plant performance during early growth, peak biomass, and senescent life stages across different soil types, light, and community compositions. To represent the community we used three grass species-a native, naturalized exotic, and invasive exotic. At early growth and peak biomass stages performance was measured as height, and shoot and root biomass, and at the senescent stage as seed production. Simulated N deposition 1) increased shoot biomass and height of the native and, even more so, the naturalized exotic during early growth, 2) positively affected root biomass in all species during peak biomass, and 3) had no influence on seed production at the senescent stage. Alone, N deposition was not a strong driver of plant performance; however, small differences in performance among species in response to N deposition could affect community composition in future years. In particular, if there is a pulse of N deposition during the early growth stage, the naturalized exotic may have a competitive advantage that could result in its spread. Including spatial and temporal heterogeneity in a complex, manipulative experiment provides a clearer picture of not only where N management efforts should be targeted on the landscape, but also when. PMID:27253718

  4. The Effect of Nitrogen Deposition on Plant Performance and Community Structure: Is It Life Stage Specific?

    PubMed Central

    2016-01-01

    Nitrogen (N) deposition is a key global change factor that is increasing and affecting the structure and function of many ecosystems. To determine the influence of N deposition on specific systems, however, it is crucial to understand the temporal and spatial patterns of deposition as well as the response to that deposition. Response of the receiving plant communities may depend on the life stage-specific performance of individual species. We focus on the California oak savanna because N deposition to this system is complex—characterized by hotspots on the landscape and seasonal pulses. In a greenhouse experiment, we investigated the relative influence of N deposition on plant performance during early growth, peak biomass, and senescent life stages across different soil types, light, and community compositions. To represent the community we used three grass species—a native, naturalized exotic, and invasive exotic. At early growth and peak biomass stages performance was measured as height, and shoot and root biomass, and at the senescent stage as seed production. Simulated N deposition 1) increased shoot biomass and height of the native and, even more so, the naturalized exotic during early growth, 2) positively affected root biomass in all species during peak biomass, and 3) had no influence on seed production at the senescent stage. Alone, N deposition was not a strong driver of plant performance; however, small differences in performance among species in response to N deposition could affect community composition in future years. In particular, if there is a pulse of N deposition during the early growth stage, the naturalized exotic may have a competitive advantage that could result in its spread. Including spatial and temporal heterogeneity in a complex, manipulative experiment provides a clearer picture of not only where N management efforts should be targeted on the landscape, but also when. PMID:27253718

  5. First-lactation performance in cows affected by digital dermatitis during the rearing period.

    PubMed

    Gomez, A; Cook, N B; Socha, M T; Döpfer, D

    2015-07-01

    The long-term effects of prepartum digital dermatitis (DD) on first-lactation performance were evaluated in a cohort of 719 pregnant heifers. All heifers were followed for a period of 6 mo until calving and classified on the basis of the number of DD events diagnosed during this period as type I, type II, or type III (no DD, one DD event, and multiple DD events, respectively). Health during the initial 60d in milk (DIM), reproductive and hoof health outcomes, and milk production were compared between the 3 heifer type groups. All logistic and linear models were adjusted for age, height, and girth circumference at enrollment, and the type of trace mineral supplementation during the prepartum period. Overall, cows experiencing DD during the rearing period showed worse production and health outcomes compared with healthy heifers during the first lactation. The percentages of assisted calvings, stillbirths, culled before 60 DIM, and diseased cows during the fresh period were numerically higher in type III cows compared with type I cows. However, none of these differences were statistically significant at the 95% confidence level. Significantly lower conception at first service [odds ratio (OR)=0.55, 95% confidence interval (95% CI): 0.33, 0.89] and increased number of days open (mean=24d, 95% CI: 5.2, 43) were observed in type III cows compared with type I cows. In relation to hoof health, a significantly increased risk of DD during the first lactation was found in type II and III cows (OR=5.16, 95% CI: 3.23, 8.29; and OR=12.5, 95% CI: 7.52, 21.1, respectively), as well as earlier occurrence of DD following calving (OR=59d, 95% CI=20, 96, and OR=74d, 95% CI: 37, 109). Compared with type I cows, statistically significant milk production losses during the initial 305 DIM of 199 and 335kg were estimated in type II and III cows, respectively. This difference was due to a greater rate of production decline (less persistence) after peak yield. No differences in monthly fat

  6. Analysis of Factors Affecting the Performance of RLV Thrust Cell Liners

    NASA Technical Reports Server (NTRS)

    Arnold, Steven M. (Technical Monitor); Butler, Daniel T., Jr.; Pinders, Marek-Jerzy

    2004-01-01

    The reusable launch vehicle (RLV) thrust cell liner, or thrust chamber, is a critical component of the Space Shuttle Main Engine (SSME). It is designed to operate in some of the most severe conditions seen in engineering practice. This requirement, in conjunction with experimentally observed 'dog-house' failure modes characterized by bulging and thinning of the cooling channel wall, provides the motivation to study the factors that influence RLV thrust cell liner performance. Factors or parameters believed to be directly related to the observed characteristic deformation modes leading to failure under in-service loading conditions are identified, and subsequently investigated using the cylindrical version of the higher-order theory for functionally graded materials in conjunction with the Robinson's unified viscoplasticity theory and the power-law creep model for modeling the response of the liner s constituents. Configurations are analyzed in which specific modifications in cooling channel wall thickness or constituent materials are made to determine the influence of these parameters on the deformations resulting in the observed failure modes in the outer walls of the cooling channel. The application of thermal barrier coatings and functional grading are also investigated within this context. Comparison of the higher-order theory results based on the Robinson and power-law creep model predictions has demonstrated that, using the available material parameters, the power-law creep model predicts more precisely the experimentally observed deformation leading to the 'dog-house' failure mode for multiple short cycles, while also providing much improved computational efficiency. However, for a single long cycle, both models predict virtually identical deformations. Increasing the power-law creep model coefficients produces appreciable deformations after just one long cycle that would normally be obtained after multiple cycles, thereby enhancing the efficiency of the

  7. Growth Performance of Early Finishing Gilts as Affected by Different Net Energy Concentrations in Diets

    PubMed Central

    Lee, Gang Il; Kim, Kwang-Sik; Kim, Jong Hyuk; Kil, Dong Yong

    2015-01-01

    The objectives of the current experiment were to study the response of the growth performance of early finishing gilts to different net energy (NE) concentrations in diets, and to compare the NE values of diets between calculated NE values and measured NE values using French and Dutch CVB (Centraal Veevoederbureau; Central Bureau for Livestock Feeding) NE systems. In a metabolism trail, the NE concentrations in five diets used for the growth trial were determined based on digestible nutrient concentrations, digestible energy, and metabolizable energy using a replicated 5×5 Latin square design with 10 barrows (initial body weight [BW], 39.2±2.2 kg). In a growth trial, a total of 60 early finishing gilts (Landrace×Yorkshire; initial BW, 47.7±3.5 kg) were allotted to five dietary treatments of 8.0, 9.0, 10.0, 11.0, and 12.0 MJ NE/kg (calculated, as-is basis) with 12 replicate pens and one pig per pen in a 42-d feeding experiment. The NE and amino acid (AA) concentrations in all diets were calculated based on the values from NRC (2012). Ratios between standardized ileal digestible AA and NE concentrations in all diets were closely maintained. Pigs were allowed ad libitum access to feed and water. Results indicated that calculated NE concentrations in diets (i.e., five dietary treatments) were close to measured NE concentrations using French NE system in diets. The final BW was increased (linear and quadratic, p<0.05) with increasing NE concentrations in diets. Furthermore, average daily gain (ADG) was increased (linear and quadratic, p<0.01) with increasing NE concentrations in diets. There was a quadratic relationship (p<0.01) between average daily feed intake and NE concentrations in diets. Feed efficiency (G:F) was also increased (linear, p<0.01) as NE concentrations in diets were increased. The NE intake per BW gain (kcal NE/kg of BWG) was increased (linear, p<0.01) with increasing NE concentrations in diets that were predicted from both French and Dutch CVB NE

  8. Structure performance analysis for TMT teritiary mirror system

    NASA Astrophysics Data System (ADS)

    Su, Yan-qin; Zhang, Jing-xu; Yang, Fei; Wang, Huai; Chen, Bao-gang

    2014-09-01

    TMT Tertiary Mirror System (M3S) is required to be able to track and point. It should rotate with the observing object. In this article, the schemes of Tertiary Mirror supporting assembly and position assembly are introduced. Then, the static and dynamic performance of Tertiary Mirror System has been analyzed. It is shown that, the maximum deflection is 1.024 mm, the maximum stress is 138.91MPa when gravity is affecting. The security of M3S can be assured when telescope is working at all required positions. The first nature frequency is 15.39Hz, the requirement 15 Hz has been satisfied. In addition, the response to earthquake has been estimated primarily. Results shows that when earthquake with mean return time 200 year happens in three directions simultaneous, or earthquake with mean return time 1000 years happens, the lateral support will be destroyed. Protection measures should be considered. Conclusions in this article are useful guides for the M3S design.

  9. Performance analysis of structured pedigree distributed fusion systems

    NASA Astrophysics Data System (ADS)

    Arambel, Pablo O.

    2009-05-01

    Structured pedigree is a way to compress pedigree information. When applied to distributed fusion systems, the approach avoids the well known problem of information double counting resulting from ignoring the cross-correlation among fused estimates. Other schemes that attempt to compute optimal fused estimates require the transmission of full pedigree information or raw data. This usually can not be implemented in practical systems because of the enormous requirements in communications bandwidth. The Structured Pedigree approach achieves data compression by maintaining multiple covariance matrices, one for each uncorrelated source in the network. These covariance matrices are transmitted by each node along with the state estimate. This represents a significant compression when compared to full pedigree schemes. The transmission of these covariance matrices (or a subset of these covariance matrices) allows for an efficient fusion of the estimates, while avoiding information double counting and guaranteeing consistency on the estimates. This is achieved by exploiting the additional partial knowledge on the correlation of the estimates. The approach uses a generalized version of the Split Covariance Intersection algorithm that applies to multiple estimates and multiple uncorrelated sources. In this paper we study the performance of the proposed distributed fusion system by analyzing a simple but instructive example.

  10. Structure and ductility of the heat-affected zone of welded joints of a high-strength steel

    NASA Astrophysics Data System (ADS)

    Tabatchikova, T. I.; Nosov, A. D.; Goncharov, S. N.; Gudnev, N. Z.; Delgado Reina, S. Yu.; Yakovleva, I. L.

    2014-12-01

    Methods of optical microscopy and scanning and transmission electron microscopy have been used to study the structure of welded joints of a high-strength structural steel with different types of the weld metal. The impact toughness of the heat-affected zone (HAZ) has been determined at temperatures of +20 and -40°C. Based on the fractograph investigations of the character of the fracture of the welded joints after tests for impact bending, the regions that are the most dangerous for crack initiation have been determined. Structural factors that affect the brittleness of the near-weld zone of welded joints with the austenite metal of the weld are indicated, including the existence of an austenite-bainite structure and coarse carbides, as well as the specific distribution of hydrogen.

  11. Facial affect recognition performance and event-related potentials in violent and non-violent schizophrenia patients.

    PubMed

    Frommann, Nicole; Stroth, Sanna; Brinkmeyer, Jürgen; Wölwer, Wolfgang; Luckhaus, Christian

    2013-01-01

    We investigated whether male inpatients with schizophrenia and a history of hands-on violent offences (forensic schizophrenic, FOS) are more impaired in emotion recognition than matched schizophrenia patients without any history of violence (general psychiatric schizophrenic, GPS). This should become apparent in performance in psychometry and in scalp event-related brain potentials (ERPs) evoked by pictures of facial affect. FOS and GPS (each n = 19) were matched concerning age, intelligence, comorbid addiction, medication and illness duration. FOS revealed significantly poorer affect recognition (AR) performance, especially of neutral and fear stimuli. Analysis of ERPs revealed a significant interaction of hemisphere, electrode position and group of the N250 component. Post hoc analysis of group effect showed significantly larger amplitudes in FOS at FC3. These results support the hypothesis that in FOS emotional faces are more salient and evoke higher arousal. Larger impairment in AR performance combined with higher salience and arousal may contribute to the occurrence of violent acts in schizophrenia patients. PMID:24051542

  12. Clostridium perfringens challenge and dietary fat type affect broiler chicken performance and fermentation in the gastrointestinal tract.

    PubMed

    Józefiak, D; Kierończyk, B; Rawski, M; Hejdysz, M; Rutkowski, A; Engberg, R M; Højberg, O

    2014-06-01

    The aim of the present work was to examine how different fats commonly used in the feed industry affect broiler performance, nutrient digestibility and microbial fermentation in the gastrointestinal tract of broiler chickens challenged with virulent Clostridium perfringens strains. Two experiments were carried out, each including 480-day-old male broilers (Ross 308), which were randomly distributed to eight experimental groups using six replicate pens per treatment and 10 birds per pen. In Experiment 1, birds were fed diets containing soybean oil, palm kernel fatty acid distillers, rendered pork fat and lard. In Experiment 2, birds were fed diets containing rapeseed oil, coconut oil, beef tallow and palm oil. In both experiments, the birds were either not challenged or challenged with a mixture of three C. perfringens type A strains. Irrespective of the fat type present in the diet, C. perfringens did not affect broiler chicken body weight gain (BWG) and mortality in either of the two experiments. The BWG was affected by dietary fat type in both experiments, indicating that the fatty acid composition of the fat source affects broiler growth performance. In particular, the inclusion of animal fats tended to improve final BW to a greater extent compared with the inclusion of unsaturated vegetable oils. In Experiment 2, irrespective of the dietary fat type present in the diet, C. perfringens challenge significantly impaired feed conversion ratio in the period from 14 to 28 days (1.63 v. 1.69) and at 42 days (1.65 v. 1.68). In both experiments apparent metabolizable energy values were affected by dietary fat type. Irrespective of the fat type present in the diet, C. perfringens challenge decreased the digesta pH in the crop and ileum, but had no effect in cecal contents. Moreover, in Experiment 1, total organic acid concentration in the ileum was two to three times lower on soybean oil diets as compared with other treatments, indicating that C. perfringens as well as

  13. Factors Affecting Trophic Control of Community Structure and Ecosystem Functioning in Experimental Mesocosms of Seagrass (Zostera marina L.)

    NASA Astrophysics Data System (ADS)

    Lefcheck, J.; Duffy, J.

    2008-12-01

    Nutrient loading of coastal and estuarine waters threatens seagrass communities by promoting the growth of micro- and macroalgae, which then reduce the availability of light and nutrients. However, populations of invertebrate mesograzers are able to mitigate the negative impact of eutrophication through top-down control. We performed a factorial mesocosm experiment to examine the interactive relationships between light, nutrients, and mesograzer presence in structuring experimental ecosystems of eelgrass (Zostera marina). We found that mesograzer presence strongly reduced epiphytic algal biomass in every case, which remains consistent with previous mesocosm studies. We also observed a synergistic light-by-nutrient interaction that enhanced both epiphyte biomass and mesograzer abundance. The timing of this relationship is suggestive of weaker bottom-up control. Unlike previous studies, we found that light alone rarely affected either epiphyte biomass or mesograzer abundance. We believe that this result may be due to a combination of macroalgal shading and persistent grazing. Further processing of primary and secondary producer biomasses and elemental ratios, as well as the completion of feeding assays to gauge mesograzer feeding rates on different types of algae, will serve to reinforce these conclusions and to better define the relationship between these factors.

  14. Structure-Property-Fracture Mechanism Correlation in Heat-Affected Zone of X100 Ferrite-Bainite Pipeline Steel

    NASA Astrophysics Data System (ADS)

    Li, Xueda; Ma, Xiaoping; Subramanian, S. V.; Misra, R. D. K.; Shang, Chengjia

    2015-03-01

    Structural performance of a weld joint primarily depends on the microstructural characteristics of heat-affected zone (HAZ). In this regard, the HAZ in X100 ferrite-bainite pipeline steel was studied by separating the HAZ into intercritically reheated coarse-grained (ICCG) HAZ containing and non-containing regions. These two regions were individually evaluated for Charpy impact toughness and characterized by electron back-scattered diffraction (EBSD). Low toughness of ~50 J was obtained when the notch of impact specimen encountered ICCGHAZ and high toughness of ~180 J when the notch did not contain ICCGHAZ. Fracture surface was ~60 pct brittle in the absence of ICCGHAZ, and 95 pct brittle (excluding shear lip) in the presence of ICCGHAZ in the impact tested samples. The underlying reason is the microstructure of ICCGHAZ consisted of granular bainite and upper bainite with necklace-type martensite-austenite (M-A) constituent along grain boundaries. The presence of necklace-type M-A constituent notably increases the susceptibility of cleavage microcrack nucleation. ICCGHAZ was found to be both the initiation site of the whole fracture and cleavage facet initiation site during brittle fracture propagation stage. Furthermore, the study of secondary microcracks beneath CGHAZ and ICCGHAZ through EBSD suggested that the fracture mechanism changes from nucleation-controlled in CGHAZ to propagation-controlled in ICCGHAZ because of the presence of necklace-type M-A constituent in ICCGHAZ. Both fracture mechanisms contribute to the poor toughness of the sample contained ICCGHAZ.

  15. Evaluation of factors affecting the containment performance of traditional and nanomaterial fume hoods

    NASA Astrophysics Data System (ADS)

    Dunn, Kevin Holden

    This research was conducted to: 1) evaluate different methods for measuring containment effectiveness of a nanomaterial handling enclosure; 2) to evaluate design and operational factors which may impact containment performance for a traditional constant air volume (CAV) and nano fume using computational fluid dynamics (CFD), and; 3) to assess the impact on the operator body and arm motion on nanoparticle containment of the CAV and nano fume hoods. The research approach to address these objectives starts with an evaluation of the containment effectiveness of a new nanomaterial handling enclosure using tracer gas, nanoparticle and nanoparticle handling methodologies in a real-world laboratory setting. The tracer gas and nanoparticle test results were well-correlated showing hood leakage under the same conditions and at the same sample locations. However, the nanoparticle method was more sensitive than the tracer gas test showing leakage in situations not indicated by the tracer gas tests. These experiments also identified substantial leaks near the sides of the hood sides even when the tracer gas concentration in the manikin breathing zone was not elevated. This result was consistent with new research showing that sampling in the manikin breathing zone may not be adequate to describe containment of fume hood devices. The second phase of this project provides an assessment of the internal flow patterns of a nano fume hood and a traditional CAV chemical fume hood. The impacts of design and operational differences between these hoods are investigated using both experimental measurements and numerical simulations with CFD. An investigation of the airflow patterns inside the hoods showed that large scale recirculation zones develop behind the sash for both hoods. However, the design of the side airfoils of the nano hood resulted in a secondary recirculation pattern along the sides of the hood which impacts interior contaminant dispersion and potential for leakage. The

  16. Does Congenital Deafness Affect the Structural and Functional Architecture of Primary Visual Cortex?

    PubMed Central

    Smittenaar, C.R.; MacSweeney, M.; Sereno, M.I.; Schwarzkopf, D.S.

    2016-01-01

    Deafness results in greater reliance on the remaining senses. It is unknown whether the cortical architecture of the intact senses is optimized to compensate for lost input. Here we performed widefield population receptive field (pRF) mapping of primary visual cortex (V1) with functional magnetic resonance imaging (fMRI) in hearing and congenitally deaf participants, all of whom had learnt sign language after the age of 10 years. We found larger pRFs encoding the peripheral visual field of deaf compared to hearing participants. This was likely driven by larger facilitatory center zones of the pRF profile concentrated in the near and far periphery in the deaf group. pRF density was comparable between groups, indicating pRFs overlapped more in the deaf group. This could suggest that a coarse coding strategy underlies enhanced peripheral visual skills in deaf people. Cortical thickness was also decreased in V1 in the deaf group. These findings suggest deafness causes structural and functional plasticity at the earliest stages of visual cortex. PMID:27014392

  17. Locomotor Sensory Organization Test: How Sensory Conflict Affects the Temporal Structure of Sway Variability During Gait.

    PubMed

    Chien, Jung Hung; Mukherjee, Mukul; Siu, Ka-Chun; Stergiou, Nicholas

    2016-05-01

    When maintaining postural stability temporally under increased sensory conflict, a more rigid response is used where the available degrees of freedom are essentially frozen. The current study investigated if such a strategy is also utilized during more dynamic situations of postural control as is the case with walking. This study attempted to answer this question by using the Locomotor Sensory Organization Test (LSOT). This apparatus incorporates SOT inspired perturbations of the visual and the somatosensory system. Ten healthy young adults performed the six conditions of the traditional SOT and the corresponding six conditions on the LSOT. The temporal structure of sway variability was evaluated from all conditions. The results showed that in the anterior posterior direction somatosensory input is crucial for postural control for both walking and standing; visual input also had an effect but was not as prominent as the somatosensory input. In the medial lateral direction and with respect to walking, visual input has a much larger effect than somatosensory input. This is possibly due to the added contributions by peripheral vision during walking; in standing such contributions may not be as significant for postural control. In sum, as sensory conflict increases more rigid and regular sway patterns are found during standing confirming the previous results presented in the literature, however the opposite was the case with walking where more exploratory and adaptive movement patterns are present. PMID:26329924

  18. Improved cognitive, affective and anxiety measures in patients with chronic systemic disorders following structured physical activity.

    PubMed

    Teixeira, Robson Bonoto; Marins, João Carlos Bouzas; de Sá Junior, Antonio Reis; de Carvalho, Cristiane Junqueira; da Silva Moura, Tiago Augusto; Lade, Carlos Gabriel; Rizvanov, Albert A; Kiyasov, Andrey P; Mukhamedyarov, Marat A; Zefirov, Andrey L; Palotás, András; Lima, Luciana Moreira

    2015-11-01

    Mental illnesses are frequent co-morbid conditions in chronic systemic diseases. High incidences of depression, anxiety and cognitive impairment complicate cardiovascular and metabolic disorders such as hypertension and diabetes mellitus. Lifestyle changes including regular exercise have been advocated to reduce blood pressure and improve glycaemic control. The purpose of this project was to evaluate the effect of physical training on the most prevalent corollary psychiatric problems in patients with chronic organic ailments. This longitudinal study assessed the mental health of hypertensive (age: 57 ± 8 years) and/or diabetic (age: 53 ± 8 years) patients using mini-mental state examination, Beck's depression inventory, Beck's anxiety inventory and self-reporting questionnaire-20 before and after a 3-month supervised resistance and aerobic exercise programme comprising structured physical activity three times a week. Clinically relevant improvement was observed in the Beck's depression inventory and Beck's anxiety inventory scores following the 12-week training (61%, p = 0.001, and 53%, p = 0.02, respectively). Even though statistically not significant (p = 0.398), the cognitive performance of this relatively young patient population also benefited from the programme. These results demonstrate positive effects of active lifestyle on non-psychotic mental disorders in patients with chronic systemic diseases, recommending exercise as an alternative treatment option. PMID:26410835

  19. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring.

    PubMed

    Han, Chuanjun; Zhang, Han; Zhang, Jie

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  20. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    PubMed Central

    Han, Chuanjun

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582