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Sample records for affects group performance

  1. Social status and housing factors affect reproductive performance of pregnant sows in groups.

    PubMed

    Salak-Johnson, Janeen L

    2017-09-01

    Group-housing systems for pregnant sows are considered a welfare-promoting alternative to the individual stall. A major concern associated with pregnant sows housed in group pens is increased aggression at mixing and at feeding, which may cause chronic stress among some of the sows in the group due to low feed intake and social stress. Prolonged activation of the stress axis, based on elevated cortisol levels, may inhibit or impair reproductive success via disruption of the reproductive axis. Mixing sows into groups shortly after insemination evokes a stress response, which may affect fertilization and implantation due to sustained, elevated cortisol levels that disrupt reproductive processes. Yet, most studies reported minimal effects of group housing sows during pregnancy on reproduction or cortisol-related stress response. Differences between housing systems-in terms of group size, floor-space allowance, feeding system, and genetics-could account for these unexpected results. Indeed, interrupted feed intake, especially in early pregnancy, and sustained aggression in late pregnancy are two unfavorable social stresses that deserve special attention in order to achieve good reproductive performance. Unfortunately, most studies do not consider other factors, such as social rank and parity, which may interactively affect reproductive success and aggressive behavior of sows, especially in group-pen systems. © 2017 Wiley Periodicals, Inc.

  2. Do Dental Students' Personality Types and Group Dynamics Affect Their Performance in Problem-Based Learning?

    PubMed

    Ihm, Jung-Joon; An, So-Youn; Seo, Deog-Gyu

    2017-06-01

    The aim of this study was to determine whether the personality types of dental students and their group dynamics were linked to their problem-based learning (PBL) performance. The Myers-Briggs Type Indicator (MBTI) instrument was used with 263 dental students enrolled in Seoul National University School of Dentistry from 2011 to 2013; the students had participated in PBL in their first year. A four-session PBL setting was designed to analyze how individual personality types and the diversity of their small groups were associated with PBL performance. Overall, the results showed that the personality type of PBL performance that was the most prominent was Judging. As a group became more diverse with its different constituent personality characteristics, there was a tendency for the group to be higher ranked in terms of PBL performance. In particular, the overperforming group was clustered around three major profiles: Extraverted Intuitive Thinking Judging (ENTJ), Introverted Sensing Thinking Judging (ISTJ), and Extraverted Sensing Thinking Judging (ESTJ). Personality analysis would be beneficial for dental faculty members in order for them to understand the extent to which cooperative learning would work smoothly, especially when considering group personalities.

  3. 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…

  4. When sad groups expect to meet again: interactive affective sharing and future interaction expectation as determinants of work groups' analytical and creative task performance.

    PubMed

    Klep, Annefloor H M; Wisse, Barbara; van der Flier, Henk

    2013-12-01

    The present study examines the moderating role of future interaction expectation in the relationship between affective sharing and work groups' task performance. We argue that group affect, a group defining characteristic, becomes more salient to its members when it is interactively shared, and that the anticipation of future interaction may strengthen the effects of group defining characteristics on subsequent group member behaviour. As a consequence, interactive sharing (vs. non-interactive sharing) of negative affect is more likely to influence work group outcomes when group members expect to meet again. Results from a laboratory experiment with 66 three-person work groups indeed show that interactively shared (vs. non-interactively shared) negative affect facilitated work groups' analytical task performance, whereas it inhibited performance on a creative fluency task when groups have expectations of future interaction and not when they do not have such expectations. The discussion focuses on how these results add to theory on group affect and contribute to insights in the effects of future interaction expectation.

  5. 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.

  6. 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.

  7. 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.

  8. Group performance and decision making.

    PubMed

    Kerr, Norbert L; Tindale, R Scott

    2004-01-01

    Theory and research on small group performance and decision making is reviewed. Recent trends in group performance research have found that process gains as well as losses are possible, and both are frequently explained by situational and procedural contexts that differentially affect motivation and resource coordination. Research has continued on classic topics (e.g., brainstorming, group goal setting, stress, and group performance) and relatively new areas (e.g., collective induction). Group decision making research has focused on preference combination for continuous response distributions and group information processing. New approaches (e.g., group-level signal detection) and traditional topics (e.g., groupthink) are discussed. New directions, such as nonlinear dynamic systems, evolutionary adaptation, and technological advances, should keep small group research vigorous well into the future.

  9. Emergent Power Hierarchies and Group Performance.

    PubMed

    Frauendorfer, Denise; Schmid Mast, Marianne; Sanchez-Cortes, Dairazalia; Gatica-Perez, Daniel

    2015-10-01

    In newly formed groups, informal hierarchies emerge automatically and readily. In this study, we argue that emergent group hierarchies enhance group performance (Hypothesis 1) and we assume that the more the power hierarchy within a group corresponds to the task-competence differences of the individual group members, the better the group performs (Hypothesis 2). Twelve three-person groups and 28 four-person groups were investigated while solving the Winter Survival Task. Results show that emerging power hierarchies positively impact group performance but the alignment between task-competence and power hierarchy did not affect group performance. Thus, emergent power hierarchies are beneficial for group performance and although they were on average created around individual group members' competence, this correspondence was not a prerequisite for better group performance.

  10. Affect and Engagement during Small Group Instruction

    ERIC Educational Resources Information Center

    Linnenbrink-Garcia, Lisa; Rogat, Toni Kempler; Koskey, Kristin L. K.

    2011-01-01

    Two studies (Study 1: n = 137; Study 2: n = 192) were conducted to investigate how upper-elementary students' affect during small group instruction related to their social-behavioral engagement during group work. A circumplex model of affect consisting of valence (positive, negative) and activation (high, low) was used to examine the relation of…

  11. Affect and Engagement during Small Group Instruction

    ERIC Educational Resources Information Center

    Linnenbrink-Garcia, Lisa; Rogat, Toni Kempler; Koskey, Kristin L. K.

    2011-01-01

    Two studies (Study 1: n = 137; Study 2: n = 192) were conducted to investigate how upper-elementary students' affect during small group instruction related to their social-behavioral engagement during group work. A circumplex model of affect consisting of valence (positive, negative) and activation (high, low) was used to examine the relation of…

  12. Interteaching: Discussion Group Size and Course Performance

    ERIC Educational Resources Information Center

    Truelove, Jacob C.; Saville, Bryan K.; Van Patten, Ryan

    2013-01-01

    Researchers have yet to examine whether discussion group size affects student performance in an interteaching-based course. In the current study, we addressed this question by manipulating discussion group size (smaller groups of 2 students vs. larger groups of 4 students) across 2 sections of an undergraduate psychology course. We found no…

  13. Psychological factors affecting equine performance

    PubMed Central

    2012-01-01

    For optimal individual performance within any equestrian discipline horses must be in peak physical condition and have the correct psychological state. This review discusses the psychological factors that affect the performance of the horse and, in turn, identifies areas within the competition horse industry where current behavioral research and established behavioral modification techniques could be applied to further enhance the performance of animals. In particular, the role of affective processes underpinning temperament, mood and emotional reaction in determining discipline-specific performance is discussed. A comparison is then made between the training and the competition environment and the review completes with a discussion on how behavioral modification techniques and general husbandry can be used advantageously from a performance perspective. PMID:23016987

  14. Performance monitoring during a minimal group manipulation.

    PubMed

    Pfabigan, Daniela M; Holzner, Marie-Theres; Lamm, Claus

    2016-10-01

    The on-going (self-)monitoring of our behaviour is inextricably intertwined with the surrounding social context. In this study, we investigated whether a minimal group paradigm assigning individuals to arbitrary group categories is powerful enough to induce changes in behavioural, psychophysiological and event-related potential correlates of performance monitoring. Following arbitrary group assignment based on ostensible task performance and a group identification task, 22 volunteers performed a flanker-task during both in-group and out-group contexts, while electroencephalography was performed. More errors were committed in the out-group compared with the in-group context. Error-related negativity amplitudes were larger for in-group compared with out-group errors. However, subsequent processing reflected in late Pe amplitudes and stimulus-driven conflict reflected in N2 amplitudes were not affected by the group context. Heart rate deceleration (during both correct and incorrect trials) tended to be more pronounced during the out-group compared with the in-group context. This surprising observation was corroborated by subjective ratings of performance satisfaction, in which participants reported higher satisfaction with their out-group performance. This study identified specific stimulus evaluation processes to be affected by a minimal group manipulation and demonstrated thereby transient top-down effects of a social context manipulation on performance monitoring.

  15. Performativity and Affect in Education

    ERIC Educational Resources Information Center

    Ruitenberg, Claudia W.

    2015-01-01

    This essay examines the concept of performativity in relation to what are perceived to be reasonable and unreasonable affective responses to discourse. It considers how discourse, especially in classrooms and other educational contexts, produces effects, and how it is that those effects are sometimes seen as attached to the discourse, and…

  16. 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.

  17. Inferring Group Processes from Computer-Mediated Affective Text Analysis

    SciTech Connect

    Schryver, Jack C; Begoli, Edmon; Jose, Ajith; Griffin, Christopher

    2011-02-01

    Political communications in the form of unstructured text convey rich connotative meaning that can reveal underlying group social processes. Previous research has focused on sentiment analysis at the document level, but we extend this analysis to sub-document levels through a detailed analysis of affective relationships between entities extracted from a document. Instead of pure sentiment analysis, which is just positive or negative, we explore nuances of affective meaning in 22 affect categories. Our affect propagation algorithm automatically calculates and displays extracted affective relationships among entities in graphical form in our prototype (TEAMSTER), starting with seed lists of affect terms. Several useful metrics are defined to infer underlying group processes by aggregating affective relationships discovered in a text. Our approach has been validated with annotated documents from the MPQA corpus, achieving a performance gain of 74% over comparable random guessers.

  18. Affective ambiguity for a group recruits ventromedial prefrontal cortex.

    PubMed

    Simmons, Alan; Stein, Murray B; Matthews, Scott C; Feinstein, Justin S; Paulus, Martin P

    2006-01-15

    Affective appraisal often involves processing complex and ambiguous stimuli, such as the mood of a group people. However, affective neuroimaging research often uses individual faces as stimuli when exploring the neural circuitry involved in social appraisal. Results from studies using single face paradigms may not generalize to settings where multiple faces are simultaneously processed. The goal of the current study was to use a novel task that presents groups of affective faces to probe the medial prefrontal cortex (PFC), a region that is critically involved in appraisal of ambiguous affective stimuli, in healthy volunteers. In the current study, 27 subjects performed the Wall of Faces (WOF) task in which multiple matrices of faces were briefly presented during functional MRI. Subjects were asked to decide whether there were more angry or happy faces (emotional decision) or whether there were more male or female faces (gender decision). In each condition, the array contained either an equal (ambiguous trials) or an unequal (unambiguous trials) distribution of one affect or gender. Ambiguous trials relative to unambiguous trials activated regions implicated in conflict monitoring and cognitive control, including the dorsal anterior cingulate cortex (ACC), dorsolateral PFC, and posterior parietal cortex. When comparing ambiguous affective decisions with ambiguous gender decisions, the ventromedial PFC (including the ventral ACC) was significantly more active. This supports the dissociation of the ACC into dorsal cognitive and ventral affective divisions, and suggests that the ventromedial PFC may play a critical role in appraising affective tone in a complex display of multiple human faces.

  19. Does Group Composition Affect Learning by Invention?

    ERIC Educational Resources Information Center

    Wiedmann, Michael; Leach, Ryan C.; Rummel, Nikol; Wiley, Jennifer

    2012-01-01

    Schwartz and Martin ("Cogn Instr" 22:129-184, 2004) as well as Kapur ("Instr Sci", this issue, 2012) have found that students can be better prepared to learn about mathematical formulas when they try to invent them in small groups before receiving the canonical formula from a lesson. The purpose of the present research was to investigate how the…

  20. Does Group Composition Affect Learning by Invention?

    ERIC Educational Resources Information Center

    Wiedmann, Michael; Leach, Ryan C.; Rummel, Nikol; Wiley, Jennifer

    2012-01-01

    Schwartz and Martin ("Cogn Instr" 22:129-184, 2004) as well as Kapur ("Instr Sci", this issue, 2012) have found that students can be better prepared to learn about mathematical formulas when they try to invent them in small groups before receiving the canonical formula from a lesson. The purpose of the present research was to investigate how the…

  1. Equity Issues in Collaborative Group Assessment: Group Composition and Performance.

    ERIC Educational Resources Information Center

    Webb, Noreen M.; Nemer, Kariane M.; Chizhik, Alexander W.; Sugrue, Brenda

    1998-01-01

    Investigated the effects of group ability composition on group processes and outcomes in science performance assessments. Findings from 21 eighth-grade science classes (445 students) show that group ability composition has a great impact on performance and that heterogeneous groups provide more of a benefit for below-average students than a…

  2. Exposure to scientific theories affects women's math performance.

    PubMed

    Dar-Nimrod, Ilan; Heine, Steven J

    2006-10-20

    Stereotype threat occurs when stereotyped groups perform worse as their group membership is highlighted. We investigated whether stereotype threat is affected by accounts for the origins of stereotypes. In two studies, women who read of genetic causes of sex differences performed worse on math tests than those who read of experiential causes.

  3. Group Performance in Information Systems Project Groups: An Empirical Study

    ERIC Educational Resources Information Center

    Bahli, Bouchaib; Buyukkurt, Meral Demirbag

    2005-01-01

    The importance of teamwork in Information Systems Development (ISD) practice and education has been acknowledged but not studied extensively to date. This paper tests a model of how groups participating in ISD projects perform and examines the relationships between some antecedents of this performance based on group research theory well…

  4. Group Performance in Information Systems Project Groups: An Empirical Study

    ERIC Educational Resources Information Center

    Bahli, Bouchaib; Buyukkurt, Meral Demirbag

    2005-01-01

    The importance of teamwork in Information Systems Development (ISD) practice and education has been acknowledged but not studied extensively to date. This paper tests a model of how groups participating in ISD projects perform and examines the relationships between some antecedents of this performance based on group research theory well…

  5. How Performance Assessments Affect Teaching and Learning.

    ERIC Educational Resources Information Center

    Khattri, Nidhi; And Others

    1995-01-01

    Summarizes results of a 3-year national study of performance assessments' effects on teaching and learning, based on visits to 16 schools implementing these assessments. Performance assessments marginally affected curriculum, but substantially influenced instruction and teacher role. Changing assignment and assessment format will not increase…

  6. Group Motivation and Group Task Performance: The Expectancy-Valence Theory Approach.

    ERIC Educational Resources Information Center

    Nakanishi, Masayuki

    1988-01-01

    Investigated effects of group motivation on group task performance. Created two levels of valence, expectancy and instrumentality. Valence variable reflected on group productivity on unstructured and task persistence measures. Expectancy variable's effect was on task persistence measure. Instrumentality affected group productivity on structured…

  7. Biomechanics of cycling and factors affecting performance.

    PubMed

    Too, D

    1990-11-01

    Cycling performance in human powered vehicles is affected by the interaction of a number of variables, including environment, mechanical and human factors. Engineers have generally focused on the design and development of faster, more efficient human-powered vehicles based on minimising aerodynamic drag, neglecting the human component. On the other hand, kinesiologists have examined cycling performance from a human perspective, but have been constrained by the structure of a standard bicycle. Therefore, a gap exists between research in the various disciplines. To maximise/optimise cycling performance in human-powered vehicles requires a bridging of this gap through interdisciplinary research. Changes in different variables can affect the energy requirements of cycling. These variables include: (a) changes in body position, configuration, and orientation; (b) changes in seat to pedal distance; and (c) the interaction of workload, power output, and pedalling rate. Changes in these variables alter joint angles, muscle lengths, and muscle moment arm lengths, thus affecting the tension-length, force-velocity-power relationships of multi-joint muscles and the effectiveness of force production. This is ultimately manifested as a change in the energetics of cycling. A large number of factors affect cycling performance in human-powered vehicles and a gap still exists between cycling research in various disciplines. To bridge this gap, if not completely close it, requires cooperation between disciplines and further interdisciplinary research.

  8. Group interaction and flight crew performance

    NASA Technical Reports Server (NTRS)

    Foushee, H. Clayton; Helmreich, Robert L.

    1988-01-01

    The application of human-factors analysis to the performance of aircraft-operation tasks by the crew as a group is discussed in an introductory review and illustrated with anecdotal material. Topics addressed include the function of a group in the operational environment, the classification of group performance factors (input, process, and output parameters), input variables and the flight crew process, and the effect of process variables on performance. Consideration is given to aviation safety issues, techniques for altering group norms, ways of increasing crew effort and coordination, and the optimization of group composition.

  9. Group Composition Affecting Student Interaction and Achievement: Instructors' Perspectives

    ERIC Educational Resources Information Center

    Lei, Simon A.; Kuestermeyer, Bailey N.; Westmeyer, Kara A.

    2010-01-01

    Multiple research studies have been conducted that focus on various uses of collaborative learning in and out of the classroom in higher education institutions. The purpose of this article is to review previously published literature regarding group composition and how it affects student interaction and achievement. Group composition research has…

  10. Group Composition Affecting Student Interaction and Achievement: Instructors' Perspectives

    ERIC Educational Resources Information Center

    Lei, Simon A.; Kuestermeyer, Bailey N.; Westmeyer, Kara A.

    2010-01-01

    Multiple research studies have been conducted that focus on various uses of collaborative learning in and out of the classroom in higher education institutions. The purpose of this article is to review previously published literature regarding group composition and how it affects student interaction and achievement. Group composition research has…

  11. How Do Efforts to Enhance Career Preparation Affect Peer Groups?

    ERIC Educational Resources Information Center

    Kiuru, Noona; Koivisto, Petri; Mutanen, Pertti; Vuori, Jukka; Nurmi, Jari-Erik

    2011-01-01

    The present study investigated how efforts to enhance career preparation affect peer groups. The participants were 710 9th graders who were randomized into control and intervention groups and assessed 3 times during 1 academic year: at baseline (T1, Fall), immediately after the career preparation intervention (T2, 3 months after baseline), and 5…

  12. Encounter Group Effects of Soccer Team Performance.

    ERIC Educational Resources Information Center

    Magen, Zipora

    1980-01-01

    Suggests that a positive relationship exists between encounter group experience and the soccer team performance--a conclusion worthy of consideration in further research in the fields of psychology and sociology of sports. (Author)

  13. Group affective learning in training for psychotherapy and psychoanalysis.

    PubMed

    Scharff, Jill Savege; Scharff, David E

    2017-03-04

    This paper describes The Group Affective Model, a method for teaching psychoanalytic concepts and their clinical application, using multi-channel teaching, process and review in group settings, and learning from experience in an open systems learning community for psychoanalysts and psychotherapists. This innovation arose in response to criticism of existing methods in psychoanalytic education that have subordinated the primary educational task to that of the training analysis. Noticing this split between education and training analysis, between cognition and affect, and between concepts of individual and group unconscious processes, we developed the Group Affective Model for teaching and learning psychoanalysis and psychotherapy in an open psychological space in which students and faculty experience individual and group processes of digestion, assimilation, and review, which demonstrate the concepts in action and make them available for internalization selectively. We discuss our philosophy and our educational stance. We describe our institution and our participants. We give examples of teaching situations that we have studied to provide some insight about assimilation and internalization of the concepts and clinical approaches being taught. We discuss the transferability of the Group Affective Model to other teaching settings and psychoanalytic training institutions and propose it as the fourth pillar of psychoanalytic training, next to analytic treatment, clinical supervision, and didactic seminars.

  14. Idea Bank: Favorite Music for Performing Groups.

    ERIC Educational Resources Information Center

    Lutter, Denise; And Others

    1989-01-01

    Offers suggestions from directors, music teachers, and other specialists, for performance pieces especially enjoyed by students. Music covers a wide range of difficulties, and suggestions are provided for elementary, secondary, and college age performers. Arrangements are for full and string orchestras, choral groups, symphonic and concert bands,…

  15. Perceptual Grouping Affects Haptic Enumeration Over the Fingers.

    PubMed

    Overvliet, Krista E; Plaisier, Myrthe A

    2016-01-01

    Spatial arrangement is known to influence enumeration times in vision. In haptic enumeration, it has been shown that dividing the total number of items over the two hands can speed up enumeration. Here we investigated how spatial arrangement of items and non-items presented to the individual fingers impacts enumeration times. More specifically, we tested whether grouping by proximity facilitates haptic serial enumeration (counting). Participants were asked to report the number of tangible items, amongst non-items, presented to the finger pads of both hands. In the first experiment, we divided the tangible items in one, two, or three groups that were defined by proximity (i.e., one nonitem in between two groups) and found that number of groups and not number of items were the critical factor in enumeration times. In a second experiment, we found that this grouping even takes place when groups extend across fingers of both hands. These results suggest that grouping by proximity affects haptic serial enumeration and that this grouping takes place on a spatial level possibly in addition to the somatotopic level. Our results support the idea that grouping by proximity, a principle introduced in vision, also greatly affects haptic processing of spatial information.

  16. Language Experience Affects Grouping of Musical Instrument Sounds.

    PubMed

    Bhatara, Anjali; Boll-Avetisyan, Natalie; Agus, Trevor; Höhle, Barbara; Nazzi, Thierry

    2016-09-01

    Language experience clearly affects the perception of speech, but little is known about whether these differences in perception extend to non-speech sounds. In this study, we investigated rhythmic perception of non-linguistic sounds in speakers of French and German using a grouping task, in which complexity (variability in sounds, presence of pauses) was manipulated. In this task, participants grouped sequences of auditory chimeras formed from musical instruments. These chimeras mimic the complexity of speech without being speech. We found that, while showing the same overall grouping preferences, the German speakers showed stronger biases than the French speakers in grouping complex sequences. Sound variability reduced all participants' biases, resulting in the French group showing no grouping preference for the most variable sequences, though this reduction was attenuated by musical experience. In sum, this study demonstrates that linguistic experience, musical experience, and complexity affect rhythmic grouping of non-linguistic sounds and suggests that experience with acoustic cues in a meaningful context (language or music) is necessary for developing a robust grouping preference that survives acoustic variability. Copyright © 2015 Cognitive Science Society, Inc.

  17. Habitual routines in task-performing groups

    NASA Technical Reports Server (NTRS)

    Gersick, C. J.; Hackman, J. R.

    1990-01-01

    Groups, like individuals, often develop habitual routines for dealing with frequently encountered stimuli. Although such routines are consequential for group life and work, little is known about them. This paper reconnoiters the territory of habitual behavior in groups that perform work within organizations. We offer a definition of group habits, identify their functions and dysfunctions, suggest how they develop and are maintained, and identify the circumstances when they are likely to be altered or abandoned. Throughout, we give special attention to the social nature of habitual routines in groups, to the interaction between habitual behavior and group life cycle phenomena, and to the role of the organizational context in prompting, shaping, and terminating habitual routines.

  18. Habitual routines in task-performing groups

    NASA Technical Reports Server (NTRS)

    Gersick, C. J.; Hackman, J. R.

    1990-01-01

    Groups, like individuals, often develop habitual routines for dealing with frequently encountered stimuli. Although such routines are consequential for group life and work, little is known about them. This paper reconnoiters the territory of habitual behavior in groups that perform work within organizations. We offer a definition of group habits, identify their functions and dysfunctions, suggest how they develop and are maintained, and identify the circumstances when they are likely to be altered or abandoned. Throughout, we give special attention to the social nature of habitual routines in groups, to the interaction between habitual behavior and group life cycle phenomena, and to the role of the organizational context in prompting, shaping, and terminating habitual routines.

  19. Language Experience Affects Grouping of Musical Instrument Sounds

    ERIC Educational Resources Information Center

    Bhatara, Anjali; Boll-Avetisyan, Natalie; Agus, Trevor; Höhle, Barbara; Nazzi, Thierry

    2016-01-01

    Language experience clearly affects the perception of speech, but little is known about whether these differences in perception extend to non-speech sounds. In this study, we investigated rhythmic perception of non-linguistic sounds in speakers of French and German using a grouping task, in which complexity (variability in sounds, presence of…

  20. Language Experience Affects Grouping of Musical Instrument Sounds

    ERIC Educational Resources Information Center

    Bhatara, Anjali; Boll-Avetisyan, Natalie; Agus, Trevor; Höhle, Barbara; Nazzi, Thierry

    2016-01-01

    Language experience clearly affects the perception of speech, but little is known about whether these differences in perception extend to non-speech sounds. In this study, we investigated rhythmic perception of non-linguistic sounds in speakers of French and German using a grouping task, in which complexity (variability in sounds, presence of…

  1. Unintended Cognitive, Affective, and Behavioral Consequences of Group Assignments

    ERIC Educational Resources Information Center

    Neu, Wayne A.

    2012-01-01

    Pedagogical strategies can be thought of as a set of stimuli placed in students' environment to influence their cognition, affect, and behavior. The design of strategies such as group assignments and a comprehensive understanding of their consequences for students should then include an analysis of all three of these elements and the…

  2. Collective hormonal profiles predict group performance

    PubMed Central

    Akinola, Modupe; Page-Gould, Elizabeth; Mehta, Pranjal H.; Lu, Jackson G.

    2016-01-01

    Prior research has shown that an individual’s hormonal profile can influence the individual’s social standing within a group. We introduce a different construct—a collective hormonal profile—which describes a group’s hormonal make-up. We test whether a group’s collective hormonal profile is related to its performance. Analysis of 370 individuals randomly assigned to work in 74 groups of three to six individuals revealed that group-level concentrations of testosterone and cortisol interact to predict a group’s standing across groups. Groups with a collective hormonal profile characterized by high testosterone and low cortisol exhibited the highest performance. These collective hormonal level results remained reliable when controlling for personality traits and group-level variability in hormones. These findings support the hypothesis that groups with a biological propensity toward status pursuit (high testosterone) coupled with reduced stress-axis activity (low cortisol) engage in profit-maximizing decision-making. The current work extends the dual-hormone hypothesis to the collective level and provides a neurobiological perspective on the factors that determine who rises to the top across, not just within, social hierarchies. PMID:27528679

  3. Members' needs, intragroup conflict, and group performance.

    PubMed

    Chun, Jinseok S; Choi, Jin Nam

    2014-05-01

    Focusing on "what people want in their group" as a critical antecedent of intragroup conflict, the present study theorizes and empirically investigates the relationships among the psychological needs of group members, intragroup conflict, and group performance. It attends to the within-group average and dispersion of members' psychological needs and examines the effects stemming from group composition of needs on multiple types of conflict. The analyses based on multisource data from 145 organizational teams revealed significant relationships between the groups' composition with respect to the members' need for achievement and task conflict, need for affiliation and relationship conflict, and need for power and status conflict. Some of these relationships were moderated by open communication among members. The analyses also demonstrated that when the 3 types of conflict were considered together, task conflict was a positive predictor of group performance, whereas relationship conflict was a negative predictor. The findings highlight the motivational aspects of intragroup conflict, revealing the multilevel dynamics of the psychological needs in social settings. (c) 2014 APA, all rights reserved.

  4. Learning with Computers in Small Groups: Cognitive and Affective Outcomes.

    ERIC Educational Resources Information Center

    Mevarech, Zemira R.; And Others

    1991-01-01

    Examines the effects of cooperative and individualistic computer-assisted instruction (CAI) programs on cognitive and affective variables in Israeli grade six mathematics classes. Analyses of the data indicate that students who used CAI for drill and practice in pairs performed better than students who used the same program individually. (30…

  5. Peer Grouping: The Refinement of Performance Indicators

    ERIC Educational Resources Information Center

    Hom, Willard

    2008-01-01

    Community colleges operate under much scrutiny these days, and these institutions have experienced a growing emphasis on performance indicators as paths to institutional accountability. California's system of 109 community colleges recently developed and implemented an innovative accountability program that used peer group comparison as one of its…

  6. Determinants of individual and group performance

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1986-01-01

    A broad exploration of individual and group/organizational factors that influence performance in demanding environments such as space and air transport was undertaken. Primary efforts were directed toward defining critical issues, developing new methodologies for the assessment of performance in such environments, and developing new measures of personality and attitudes as predictors of performance. Substantial clarification of relevant issues for research and validation was achieved. A reliable instrument to assess crewmembers' attitudes regarding crew coordination and flightdeck management was validated. Major efforts in data collection to validate concepts were initiated. The results suggest that substantial improvements can be made in the prediction of performance and in the selection of crewmembers for aviation and space.

  7. Sleep complaints affecting school performance at different educational levels.

    PubMed

    Pagel, James F; Kwiatkowski, Carol F

    2010-01-01

    The clear association between reports of sleep disturbance and poor school performance has been documented for sleepy adolescents. This study extends that research to students outside the adolescent age grouping in an associated school setting (98 middle school students, 67 high school students, and 64 college students). Reported restless legs and periodic limb movements are significantly associated with lower GPA's in junior high students. Consistent with previous studies, daytime sleepiness was the sleep variable most likely to negatively affects high school students. Sleep onset and maintenance insomnia were the reported sleep variables significantly correlated with poorer school performance in college students. This study indicates that different sleep disorder variables negatively affect performance at different age and educational levels.

  8. The Impact of Group Diversity on Class Performance: Evidence from College Classrooms

    ERIC Educational Resources Information Center

    Hansen, Zeynep; Owan, Hideo; Pan, Jie

    2015-01-01

    We combine class performance data from an undergraduate management course with students' personal records to examine how group diversity affects group work performance and individual learning. Students are exogenously assigned to groups. We find that, on average, male-dominant groups performed worse in their group work and learned less (based…

  9. The Impact of Group Diversity on Class Performance: Evidence from College Classrooms

    ERIC Educational Resources Information Center

    Hansen, Zeynep; Owan, Hideo; Pan, Jie

    2015-01-01

    We combine class performance data from an undergraduate management course with students' personal records to examine how group diversity affects group work performance and individual learning. Students are exogenously assigned to groups. We find that, on average, male-dominant groups performed worse in their group work and learned less (based…

  10. Attribution, Affect, and College Exam Performance.

    ERIC Educational Resources Information Center

    Arkin, Robert M.; Maruyama, Geoffrey M.

    1979-01-01

    College students attributed their own performance and the performance of the average student to ability, test difficulty, preparation, and luck. Successful students perceived internal factors and unsuccessful students perceived external factors as more important causes of their own performance. Students' anxiety and their ratings of the course and…

  11. Relative Age Affects Marathon Performance in Male and Female Athletes

    PubMed Central

    Connick, Mark J.; Beckman, Emma M.; Tweedy, Sean M.

    2015-01-01

    Marathon runners are ranked in 5-year age groups. However the extent to which 5-year groupings facilitates equitable competition has not been evaluated. The aim of this study was to evaluate the effect of relative age in male and female marathon running. Marathon finishing times for the top ten male (aged 20-69 years) and female athletes (aged 20-64 years) were obtained from the 2013 New York and Chicago marathons. Intra-class and inter-class validity were evaluated by comparing performances within (intra-class) and between (inter-class) the 5-year age groups. Results showed intra-class effects in all male age groups over 50 years, in all female age groups over 40 years, and in male and female 20-24 age groups (p < 0.05). Inter-class differences existed between the 20-24 and 25-29 age groups in both males and females, between all male age groups over 50 years, and between all female age groups over 40 years (p < 0.05). This study provided the first evaluation of the effects of relative age in male and female marathon running. The results provide preliminary but compelling evidence that the relatively older male athletes in age groups over 50 years and the relatively older females in age groups over 40 years are competitively disadvantaged compared to the younger athletes in these age groups. Key points Results showed a curvilinear relationship between age and marathon running performance with the negative effect of age becoming more pronounced in older runners. Relative age effects were found in all age groups over age 50 years in males and over age 40 years in females indicating that the relatively older runners were competitively disadvantaged compared to the relatively younger runners in these age groups. Relative age affected the 20-24 age classification which is consistent with the hypothesis that marathon performance improves until peak performance occurs in the 25-29 age classification. PMID:26336355

  12. Relative Age Affects Marathon Performance in Male and Female Athletes.

    PubMed

    Connick, Mark J; Beckman, Emma M; Tweedy, Sean M

    2015-09-01

    Marathon runners are ranked in 5-year age groups. However the extent to which 5-year groupings facilitates equitable competition has not been evaluated. The aim of this study was to evaluate the effect of relative age in male and female marathon running. Marathon finishing times for the top ten male (aged 20-69 years) and female athletes (aged 20-64 years) were obtained from the 2013 New York and Chicago marathons. Intra-class and inter-class validity were evaluated by comparing performances within (intra-class) and between (inter-class) the 5-year age groups. Results showed intra-class effects in all male age groups over 50 years, in all female age groups over 40 years, and in male and female 20-24 age groups (p < 0.05). Inter-class differences existed between the 20-24 and 25-29 age groups in both males and females, between all male age groups over 50 years, and between all female age groups over 40 years (p < 0.05). This study provided the first evaluation of the effects of relative age in male and female marathon running. The results provide preliminary but compelling evidence that the relatively older male athletes in age groups over 50 years and the relatively older females in age groups over 40 years are competitively disadvantaged compared to the younger athletes in these age groups. Key pointsResults showed a curvilinear relationship between age and marathon running performance with the negative effect of age becoming more pronounced in older runners.Relative age effects were found in all age groups over age 50 years in males and over age 40 years in females indicating that the relatively older runners were competitively disadvantaged compared to the relatively younger runners in these age groups.Relative age affected the 20-24 age classification which is consistent with the hypothesis that marathon performance improves until peak performance occurs in the 25-29 age classification.

  13. Behavior and performance of pigs previously housed in large groups.

    PubMed

    Li, Y Z; Johnston, L J

    2009-04-01

    A study was conducted to evaluate the effects of social familiarity and initial BW variation at mixing on performance and welfare of pigs born to group-housed lactating sows. A total of 180 pigs from 24 litters were used in a random design with 4 treatments in a 2 x 2 (social familiarity x initial BW uniformity) factorial arrangement. Pigs were born in group-farrowing rooms where they mingled in large groups of 66 to 80 pigs from 10 d of age. At 8 wk of age (BW=23+/-3.1 kg), pigs were allocated to 20 pens of 9 pigs (5 castrated males and 4 females) in a grow-finish room, with 5 pens assigned to each of 4 treatment combinations without consideration of relatedness. Familiar groups consisted of pigs from 1 farrowing room, and unfamiliar groups consisted of 3 pigs from each of 3 different farrowing rooms. Uniform BW groups were formed by using the middle 2 quartiles, and variable BW groups by using the heaviest and lightest quartiles of pigs. Aggression and activity behavior were directly observed by scan or continuous sampling during a period of 4 h on the first 3 d, d 7, and d 14 after grouping. Injury scores were assessed on all pigs immediately before and 48 h after grouping. Body weight gain and apparent feed intake were measured every 2 wk for 14 wk. Aggression in familiar groups was minimal throughout the observation periods. Compared with that in familiar groups, total duration of fighting was greater in unfamiliar groups on d 0 (upon grouping, 48.5 vs. 0.5+/-10.88 s/pig(-1).4 h(-1); P<0.001) and on d 1 (10.8 vs. 0.4+/-3.24 s/pig(-1).4 h(-1); P<0.05) after grouping. Unfamiliar pigs had greater injury scores (6.6 vs. 1.8+/-0.28; P<0.001) and spent less time eating on d 0 (5.1 vs. 8.8+/-0.92% of total observation time; P<0.01) after grouping compared with familiar pigs. The ADG and ADFI were decreased in unfamiliar groups during the initial 6 wk, but not for the entire 14-wk period in comparison with familiar groups. Body weight variation did not affect behavior

  14. Working for the self or working for the group: how self- versus group affirmation affects collective behavior in low-status groups.

    PubMed

    Derks, Belle; van Laar, Colette; Ellemers, Naomi

    2009-01-01

    Experiencing social identity threat can lead members of stigmatized groups to protect their self-regard by withdrawing from domains that are associated with higher status groups. Four experiments examined how providing identity affirmation in alternative domains affects performance motivation in status-defining domains among stigmatized group members. Two forms of identity affirmation were distinguished: self-affirmation, which enhances personal identity, and group affirmation, which enhances social identity. The results showed that although self- and group affirmation both induce high performance motivation, they do so in different ways. Whereas self-affirmation induces a focus on the personal self, group affirmation induces a focus on the social self (Study 1). Accordingly, group affirmation elicited high performance motivation among highly identified group members (Studies 1 and 2) by inducing challenge (Study 2) and protected interest in group-serving behaviors that improve collective status (Studies 3 and 4). By contrast, low identifiers were challenged and motivated to perform well only after self-affirmation (Studies 1 and 2) and reported an even stronger inclination to work for themselves at the expense of the group when offered group affirmation (Studies 3 and 4).

  15. 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.

  16. Critical process parameters affecting zincrometal performance

    SciTech Connect

    Iezzi, R.A.

    1984-01-01

    A laboratory study aimed at improving the corrosion resistance of Zincrometal has shown that excellent Zincrometal performance in laboratory corrosion tests can be obtained by achieving a trivalent (Cr+3) to hexavalent (Cr+6) Dacromet chromium ratio of at least 15. Increasing thermal energy input during curing increases the Cr+3/Cr+6 ratio and improves corrosion resistance in laboratory tests. Increasing curing energy input in production may be a viable approach to improve Zincrometal performance, provided that steels not susceptible to strain aging are used.

  17. Factors affecting performance during an endurance relay.

    PubMed Central

    Lloyd, E. L.; Henderson, W.; Covell, B.; Bryce, G. R.

    1977-01-01

    A successful attempt by Edinburgh Athletic Club on the world record for the 24-hour 10-man x 1 mile relay is reported. The effects of a variety of factors on the performances of the athletes are assessed, and some physiological changes noted. In the light of these observations recommendations are made to help the planning of future record attempts. PMID:922276

  18. Factors Affecting Information Literacy Perception and Performance

    ERIC Educational Resources Information Center

    Zehner, Drusilla Charlene Beecher

    2009-01-01

    Information literacy, defined as, "the set of skills needed to find, retrieve, analyze, and use information" (American Library Association, 2003, paragraph 1), is necessary for success in life. The present study will examine whether the factors of gender, race, and/or socioeconomic status impact information literacy performance and…

  19. Factors Affecting Information Literacy Perception and Performance

    ERIC Educational Resources Information Center

    Zehner, Drusilla Charlene Beecher

    2009-01-01

    Information literacy, defined as, "the set of skills needed to find, retrieve, analyze, and use information" (American Library Association, 2003, paragraph 1), is necessary for success in life. The present study will examine whether the factors of gender, race, and/or socioeconomic status impact information literacy performance and…

  20. Is Oral Performance Affected by Motivation?

    ERIC Educational Resources Information Center

    Soozandehfar, Seyyed Mohammad Ali

    2010-01-01

    The present investigation intends to make a comparison between integratively motivated students of English at Islamic Azad University of Shiraz and their instrumentally motivated peers in terms of their oral performance. To this end, 35 junior students (15 males and 20 females) were selected out of 54 initial participants based on their scores on…

  1. How Does Heredity Affect Athletic Performance?

    ERIC Educational Resources Information Center

    Cowart, Virginia S.

    1987-01-01

    This article reviews research regarding the effect of heredity on athletic performance. Research on twins indicates that genetic makeup may have a strong role in aerobic capacity, adaptability to training, composition of muscle tissue, and personality traits relating to competitiveness and leadership. (CB)

  2. Hierarchical Dynamics Affecting Work Performance in Organizations

    NASA Astrophysics Data System (ADS)

    Guastello, Stephen J.

    This research explored the impact of organizational hierarchies on the dynamics of work performance and profitability. Theoretical expectations from game theory, synergetics, and other work on coupled nonlinear dynamical processes were reviewed and were found to make different predictions regarding the impact of hierarchical organization on behavior at any one level of the organization. University students participated in experimentally contrived organizations that had either two or three levels of hierarchy. The dynamics of work performance and profitability were assessed through nonlinear regression. Results showed that, for a two-level system, work performance was chaotic at both levels of organization, with a decrease in both noise and dimensionality at the upper level. For the three-level system, however, work performance at the lowest level showed gradual, non-asymptotic, and non-chaotic increases over time. The middle and upper management behaviors displayed both dampening and accelerating oscillatory pattern over time, an increase in dimensionality between workers and middle management, and a decrease in dimensionality from middle to top management. Nonlinear models outperformed linear alternatives by a margin upwards of 1.36:1 in variance accounted for.

  3. Does posttraumatic stress disorder (PTSD) affect performance?

    PubMed

    LeBlanc, Vicki R; Regehr, Cheryl; Jelley, R Blake; Barath, Irene

    2007-08-01

    Research has increasingly identified alarming levels of traumatic stress symptoms in individuals working in emergency services and other high stress jobs. This study examined the effects of prior critical incident exposure and current posttraumatic symptoms on the performance of a nonpatient population, police recruits, during an acutely stressful event. A stressful policing situation was created through the use of a video simulator room that was responsive to actions of participants. The performance of participants to the simulated emergency was evaluated by 3 independent blinded raters. Prior exposure to critical incidents was measured using the Critical Incident History Questionnaire and current level of traumatic stress symptoms was measured using the Impact of Events Scale-Revised. Neither previous exposure to critical incidents nor trauma symptoms correlated with performance level. Recruits with high or severe levels of trauma symptoms did not demonstrate impairments in judgment, communication, or situation control compared with their colleagues with lesser or no trauma symptoms. On the basis of these findings, there is no reason to believe that police recruits with PTSD are prone to making errors of communication or judgment that would place them or others at increased risk.

  4. Factors affecting penetrating captive bolt gun performance.

    PubMed

    Gibson, Troy J; Mason, Charles W; Spence, Jade Y; Barker, Heather; Gregory, Neville G

    2015-01-01

    Captive bolt stunning is used for rendering livestock insensible at slaughter. The mechanical factors relating to performance of 6 penetrating captive bolt gun (CBG) models were examined. The Matador Super Sécurit 3000 and the .25 Cash Euro Stunner had the highest kinetic energy values (443 J and 412 J, respectively) of the CBGs tested. Ninety percent (27/30) of CBGs held at a government gun repository (United Kingdom) were found to have performed at a normal standard for the model, while 53% (10/19) of commercial contractor CBGs tested were found to underperform for the gun model. When the .22 Cash Special was fired 500 times at 4 shots per min, the gun reached a peak temperature of 88.8°C after 2.05 hr. Repeat firing during extended periods significantly reduced the performance of the CBG. When deciding on the appropriate CBG/cartridge combination, the kinetic energy delivered to the head of the nonhuman animal, bolt penetration depth, and species/animal type must be considered. It is recommended that CBGs are routinely checked for wear to the bolt and barrel if they are repeatedly fired in a session.

  5. Body position affects performance in untrained cyclists

    PubMed Central

    Ashe, M; Scroop, G; Frisken, P; Amery, C; Wilkins, M; Khan, K

    2003-01-01

    Objective: To compare cardiovascular and ventilatory variables in upright versus aero cycle ergometry at submaximal and maximal exercise intensities in untrained cyclists. Method: Ten physically active men (mean (SD) age 19.1 (1.10) years) who were unfamiliar with aerobars underwent maximal exercise testing and steady state cycling at 50, 100, and 150 W. Results: Participants had significantly greater maxima for oxygen uptake (VO2), ventilation, heart rate, and workload maximum in the upright position. During steady state cycling at the three workloads, VO2 (ml/kg/min) and gross mechanical efficiency were significantly greater in the upright position. Conclusions: In untrained subjects performing with maximal effort, the upright position permits greater VO2, ventilation, heart rate, and workload maxima. Further, in the steady state, exercise cycling may be less costly in the upright position. For this reason, untrained cyclists need to weigh body position effects against the well known aerodynamic advantages of the aero position. PMID:14514538

  6. Stimulus type affects Wada memory performance.

    PubMed

    Testa, S Marc; Ward, Julianna; Crone, Nathan E; Brandt, Jason

    2008-10-01

    The effects of amytal injection side, seizure focus laterality, and stimulus type (real and line-drawn objects, printed words, and faces) on recognition memory were studied during the Wada procedure. To-be-remembered stimuli were presented during cerebral anesthesia to 35 patients with left temporal lobe epilepsy (LTLE) and 28 patients with right temporal lobe epilepsy (RTLE), all with left hemisphere language dominance. In both groups, recognition of real and line-drawn objects was best after anesthetization of the lesional hemisphere. Recognition of faces was poor after either injection in patients with RTLE, but only after right injection in patients with LTLE. Conversely, recognition of words by patients with LTLE was impaired equally after either injection, but more so after left than right injection in patients with RTLE. The findings suggest that (1) real and line-drawn objects are "dually encoded" and memory accuracy depends on seizure focus laterality, and (2) accuracy in recognition of words and faces is related to seizure focus laterality, but may also depend on the language dominance of the hemisphere being assessed.

  7. Animal signals and emotion in music: coordinating affect across groups

    PubMed Central

    Bryant, Gregory A.

    2013-01-01

    Researchers studying the emotional impact of music have not traditionally been concerned with the principled relationship between form and function in evolved animal signals. The acoustic structure of musical forms is related in important ways to emotion perception, and thus research on non-human animal vocalizations is relevant for understanding emotion in music. Musical behavior occurs in cultural contexts that include many other coordinated activities which mark group identity, and can allow people to communicate within and between social alliances. The emotional impact of music might be best understood as a proximate mechanism serving an ultimately social function. Recent work reveals intimate connections between properties of certain animal signals and evocative aspects of human music, including (1) examinations of the role of nonlinearities (e.g., broadband noise) in non-human animal vocalizations, and the analogous production and perception of these features in human music, and (2) an analysis of group musical performances and possible relationships to non-human animal chorusing and emotional contagion effects. Communicative features in music are likely due primarily to evolutionary by-products of phylogenetically older, but still intact communication systems. But in some cases, such as the coordinated rhythmic sounds produced by groups of musicians, our appreciation and emotional engagement might be driven by an adaptive social signaling system. Future empirical work should examine human musical behavior through the comparative lens of behavioral ecology and an adaptationist cognitive science. By this view, particular coordinated sound combinations generated by musicians exploit evolved perceptual response biases – many shared across species – and proliferate through cultural evolutionary processes. PMID:24427146

  8. Animal signals and emotion in music: coordinating affect across groups.

    PubMed

    Bryant, Gregory A

    2013-01-01

    Researchers studying the emotional impact of music have not traditionally been concerned with the principled relationship between form and function in evolved animal signals. The acoustic structure of musical forms is related in important ways to emotion perception, and thus research on non-human animal vocalizations is relevant for understanding emotion in music. Musical behavior occurs in cultural contexts that include many other coordinated activities which mark group identity, and can allow people to communicate within and between social alliances. The emotional impact of music might be best understood as a proximate mechanism serving an ultimately social function. Recent work reveals intimate connections between properties of certain animal signals and evocative aspects of human music, including (1) examinations of the role of nonlinearities (e.g., broadband noise) in non-human animal vocalizations, and the analogous production and perception of these features in human music, and (2) an analysis of group musical performances and possible relationships to non-human animal chorusing and emotional contagion effects. Communicative features in music are likely due primarily to evolutionary by-products of phylogenetically older, but still intact communication systems. But in some cases, such as the coordinated rhythmic sounds produced by groups of musicians, our appreciation and emotional engagement might be driven by an adaptive social signaling system. Future empirical work should examine human musical behavior through the comparative lens of behavioral ecology and an adaptationist cognitive science. By this view, particular coordinated sound combinations generated by musicians exploit evolved perceptual response biases - many shared across species - and proliferate through cultural evolutionary processes.

  9. Does performance management affect nurses' well-being?

    PubMed

    Decramer, Adelien; Audenaert, Mieke; Van Waeyenberg, Thomas; Claeys, Tine; Claes, Claudia; Vandevelde, Stijn; van Loon, Jos; Crucke, Saskia

    2015-04-01

    This article focuses on employee performance-management practices in the healthcare sector. We specifically aim to contribute to a better understanding of the impact of employee performance-management practices on affective well-being of nurses in hospitals. Theory suggests that the features of employee-performance management (planning and evaluation of individual performances) predict affective well-being (in this study: job satisfaction and affective commitment). Performance-management planning and evaluation and affective well-being were drawn from a survey of nurses at a Flemish hospital. Separate estimations were performed for different aspects of affective well-being. Performance planning has a negative effect on job satisfaction of nurses. Both vertical alignment and satisfaction with the employee performance-management system increase the affective well-being of nurses; however, the impact of vertical alignment differs for different aspects of affective well-being (i.e. job satisfaction and affective commitment). Performance-management planning and evaluation of nurses are associated with attitudinal outcomes. The results indicate that employee performance-management features have different impacts on different aspects of well-being. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Group membership affects spontaneous mental representation: failure to represent the out-group in a joint action task.

    PubMed

    McClung, Jennifer Susan; Jentzsch, Ines; Reicher, Stephen David

    2013-01-01

    Predicting others' actions is crucial to successful social interaction. Previous research on joint action, based on a reaction-time paradigm called the Joint Simon Task, suggests that successful joint action stems from the simultaneous representation of the self with the other. Performance on this task provides a read-out of the degree of intrusion from a partner that participants experience from acting jointly compared to acting alone, which in turn is a measure of the degree to which participants mentally represent their co-actors during the task. To investigate the role of perceived group membership in this type of joint action and its influence on the representation of others, we first subjected participants to a minimal group paradigm while manipulating differences in social competition. We then asked participants to do the Joint Simon Task in pairs with an in-group or out-group member. Only participants who acted with an "in-group" partner on the joint task showed altered reaction times compared to when acting alone, presumably a change caused by the simultaneous and automatic representation of their in-group partner. In contrast, participants who acted with an out-group partner were unaffected in their reactions when doing the joint task, showing no evidence of representation of their out-group partner. This effect was present in both the high-competition and low-competition conditions, indicating that the differential effects of group membership on representation during joint action were driven by perceived group membership and independent of the effects of social competition. We concluded that participants failed to represent out-group members as socially relevant agents not based on any personality or situational characteristics, but in reaction only to their status as "other". In this way group membership appears to affect cognition on a very immediate and subconscious level.

  11. Complex contexts and relationships affect clinical decisions in group therapy.

    PubMed

    Tasca, Giorgio A; Mcquaid, Nancy; Balfour, Louise

    2016-09-01

    Clinical errors tend to be underreported even though examining them can provide important training and professional development opportunities. The group therapy context may be prone to clinician errors because of the added complexity within which therapists work and patients receive treatment. We discuss clinical errors that occurred within a group therapy in which a patient for whom group was not appropriate was admitted to the treatment and then was not removed by the clinicians. This was countertherapeutic for both patient and group. Two clinicians were involved: a clinical supervisor who initially assessed and admitted the patient to the group, and a group therapist. To complicate matters, the group therapy occurred within the context of a clinical research trial. The errors, possible solutions, and recommendations are discussed within Reason's Organizational Accident Model (Reason, 2000). In particular, we discuss clinician errors in the context of countertransference and clinician heuristics, group therapy as a local work condition that complicates clinical decision-making, and the impact of the research context as a latent organizational factor. We also present clinical vignettes from the pregroup preparation, group therapy, and supervision. Group therapists are more likely to avoid errors in clinical decisions if they engage in reflective practice about their internal experiences and about the impact of the context in which they work. Therapists must keep in mind the various levels of group functioning, especially related to the group-as-a-whole (i.e., group composition, cohesion, group climate, and safety) when making complex clinical decisions in order to optimize patient outcomes. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  12. Group reminiscence therapy for cognitive and affective function of demented elderly in Taiwan.

    PubMed

    Wang, Jing-Jy

    2007-12-01

    Elderly people with cognitive impairments are often associated with depressed mood and are heavy consumers in both medical services and need in caregivers. Reminiscence is believed to be effective in improving the cognition and mood of demented people. This study tested the hypothesis that structured group reminiscence therapy can prevent the progression of cognitive impairment and enhance affective function in the cognitively impaired elderly. A randomized controlled trial (RCT) based on a two group pre- and post-test design was used. The experimental subjects underwent eight group sessions, one session per week. The measurements were performed using Mini-Mental State Examination (MMSE), Geriatric Depression Scale short form (GDS-SF), and Cornell Scale for Depression in Dementia (CSDD). The sample consisted of 102 subjects, with 51 in the experimental group and 51 in the control group. Results demonstrated that the intervention significantly affected cognitive function and affective function as measured by MMSE and CSDD (p = 0.015 and 0.026), indicating that the cognitive function of the experimental subjects increased and their depressive symptoms diminished following intervention. Participation in reminiscence activities can be a positive and valuable experience for demented older persons. Consequently, the development of a structured care program for elderly persons with cognitive impairment and the need for long-term care is essential. Thus, health providers in long-term care facilities should be trained in reminiscence group therapy, and to be able to deliver such a program to the targeted group.

  13. Group 3: Performance evaluation and assessment

    NASA Technical Reports Server (NTRS)

    Frink, A.

    1981-01-01

    Line-oriented flight training provides a unique learning experience and an opportunity to look at aspects of performance other types of training did not provide. Areas such as crew coordination, resource management, leadership, and so forth, can be readily evaluated in such a format. While individual performance is of the utmost importance, crew performance deserves equal emphasis, therefore, these areas should be carefully observed by the instructors as an rea for discussion in the same way that individual performane is observed. To be effective, it must be accepted by the crew members, and administered by the instructors as pure training-learning through experience. To keep open minds, to benefit most from the experience, both in the doing and in the follow-on discussion, it is essential that it be entered into with a feeling of freedom, openness, and enthusiasm. Reserve or defensiveness because of concern for failure must be inhibit participation.

  14. Investigating Factors Affecting Group Processes in Virtual Learning Environments

    ERIC Educational Resources Information Center

    Hazari, Sunil; Thompson, Sandra

    2015-01-01

    With the widespread popularity of distance learning, there is a need to investigate elements of online courses that continue to pose significant challenges for educators. One of the challenges relates to creating and managing group projects. This study investigated business students' perceptions of group work in online classes. The constructs of…

  15. Investigating Factors Affecting Group Processes in Virtual Learning Environments

    ERIC Educational Resources Information Center

    Hazari, Sunil; Thompson, Sandra

    2015-01-01

    With the widespread popularity of distance learning, there is a need to investigate elements of online courses that continue to pose significant challenges for educators. One of the challenges relates to creating and managing group projects. This study investigated business students' perceptions of group work in online classes. The constructs of…

  16. 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.

  17. Rebuilding security: group therapy with children affected by September 11.

    PubMed

    Haen, Craig

    2005-07-01

    This article examines group therapy with children and adolescents impacted by the September 11 terrorist attacks on the World Trade Center, with a focus on the role of metaphor, enactment, and the creative arts therapies in trauma treatment. Attention is given to the importance of fantasies, family structure, and culture in determining how the child constructs and processes the events. Examples are derived from ongoing, trauma-focused groups with traumatically bereaved children who lost parents, as well as from ongoing drama therapy groups in which traumatic themes emerged.

  18. Unit Cohesion and the Surface Navy: Does Cohesion Affect Performance

    DTIC Science & Technology

    1989-12-01

    Relationship of Group Cohe- sion to Group Performance: A Research Integration Attempt, by L. W. Oliver, A199069, July 1988. Cartwright , D., "The Nature of...Group Cohesiveness," in Darwin Cart- wright and Alvin Zander, eds., Group Dynamics: Research and Theory, New York: Harper and Row, 1968. Gujarati, D. N

  19. 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…

  20. Nicotine improves antisaccade task performance without affecting prosaccades.

    PubMed

    Larrison, Abigail L; Briand, Kevin A; Sereno, Anne B

    2004-08-01

    Although there is ample evidence for a cognitive-attentional benefit of the stimulant nicotine, the source of this benefit is not as well understood. One approach is to address what aspects of performance nicotine affects at a functional systems level. It is currently debated whether the benefits produced by nicotine are the effect of enhanced higher cognitive function or reflect an overall increase in general arousal. In order to address this question, the effects of nicotine on two simple eye movement tasks were studied: the saccade (S) and antisaccade (AS) tasks. Because the S and AS tasks utilize identical sensory stimuli (peripheral targets) and require identical motor responses (eye movements) but differ significantly in their cognitive demands, the use of these two tasks should enable a parsing of nicotine effects on cognitive versus sensory-motor processes. In this study, the S and AS tasks were performed by two experimental groups, task naïve subjects and highly practised subjects. For the first group, that of the task naïve subjects, nicotine gum administration resulted in a decrease in AS errors. For the second group, that of two experienced subjects tested repeatedly over a 3 week period, nicotine also produced a significant decrease in AS task errors, as well as resulting in a significant decrease in AS response times. Neither task naïve nor experienced subjects showed any effects of nicotine on the S task. Examining the effects of nicotine on highly controlled and constrained tasks such as the S and AS task may provide another level of insight into the mechanisms underlying the beneficial cognitive effects of nicotine. Copyright 2004 John Wiley & Sons, Ltd.

  1. Detailed Performance Calculations: Goddard Group, Appendix D

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Two systems were described. The first used polarization to reduce scattered solar flux, the principal source of noise. The second used a narrowband detector and a different excitation wavelength. The results, which consider these systems, were presented emphasizing anticipated technology improvements because the analysis for each system required estimates of critical parameter even though each system would use existing technology. For the first, the information about the degree of polarization of the scattered solar flux was not measured but was estimated as 60 percent for viewing straight up with a solar zenith angle of 75 percent at sea level. The expected performance of this system therefore depends on the reliability of this estimate. For the second system, two estimates were required. First, the expected throughput of a Fabry-Perot interferometer operating at 309 nm, based on the performance exhibited by similar instruments working at other wavelengths, was estimated to be 3 percent. Second, the fluorescence efficiency of the proposed OH lines was estimated as 0.00004, since these quantities were not measured to date.

  2. Caregiver Support Groups: Factors Affecting Use of Services.

    ERIC Educational Resources Information Center

    Monahan, Deborah J.; And Others

    1992-01-01

    Examined effects of factors on support group attendance among family caregivers to frail elderly relatives. Found that attendance by primary caregivers was greater for those who were older, who had secondary informal caregiver involved in providing care, or who had significant health problems. Attendance was greater for those caring for…

  3. Group Membership and Writing Apprehension: Do They Affect Academic Writing?

    ERIC Educational Resources Information Center

    Cornwell, Steve

    1998-01-01

    A study investigated whether the makeup of peer editing groups in a Japanese junior college Academic English writing class had an effect on students' writing apprehension or grades over the course of a 10-week semester. Subjects were 29 first-year students from an intact Academic Writing class, with similar levels of English proficiency. Students…

  4. Attitudinal Factors Affecting Wiki Group Collaboration for English Writing

    ERIC Educational Resources Information Center

    Chen, Chwen Jen; Chuah, Kee Man; Tho, Jimmy; Teh, Chee Siong

    2015-01-01

    Wikis, being one of the popular Web 2.0 tools, have impacted students' engagement and performance particularly in the aspects of second and foreign language learning. While an increasing number of studies have focused on the effectiveness of wiki in improving students' writing skills, this study was conducted to examine the attitudinal factors…

  5. Attitudinal Factors Affecting Wiki Group Collaboration for English Writing

    ERIC Educational Resources Information Center

    Chen, Chwen Jen; Chuah, Kee Man; Tho, Jimmy; Teh, Chee Siong

    2015-01-01

    Wikis, being one of the popular Web 2.0 tools, have impacted students' engagement and performance particularly in the aspects of second and foreign language learning. While an increasing number of studies have focused on the effectiveness of wiki in improving students' writing skills, this study was conducted to examine the attitudinal factors…

  6. 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…

  7. Regular moist snuff dipping does not affect endurance exercise performance.

    PubMed

    Björkman, Frida; Edin, Fredrik; Mattsson, C Mikael; Larsen, Filip; Ekblom, Björn

    2017-01-01

    Physiological and medical effects of snuff have previously been obtained either in cross-sectional studies or after snuff administration to non-tobacco users. The effects of snuff cessation after several years of daily use are unknown. 24 participants with >2 years of daily snuff-use were tested before and after >6 weeks snuff cessation (SCG). A control group (CO) of 11 snuff users kept their normal habits. Resting heart rate (HR) and blood pressure (BP) were significantly lower in SCG after snuff cessation, and body mass was increased by 1.4 ± 1.7 kg. Total cholesterol increased from 4.12 ± 0.54 (95% CI 3.89-4.35) to 4.46 ± 0.70 (95% CI 4.16-4.75) mM L-1 in SCG, due to increased LDL, and this change was significantly different from CO. Resting values of HDL, C-reactive protein, and free fatty acids (FFA) remained unchanged in both groups. In SCG group, both HR and BP were reduced during a four-stage incremental cycling test (from 50 to 80% of VO2max) and a prolonged cycling test (60 min at 50% of VO2max). Oxygen uptake (VO2), respiratory exchange ratio, blood lactate (bLa) and blood glucose (bGlu) concentration, and rate of perceived exertion (RPE) were unchanged. In CO group, all measurements were unchanged. During the prolonged cycling test, FFA was reduced, but with no significant difference between groups. During the maximal treadmill running test peak values of VO2, pulmonary ventilation (VE), time to exhaustion and bLa were unchanged in both groups. In conclusion, endurance exercise performance (VO2max and maximal endurance time) does not seem to be affected by prolonged snuff use, while effects on cardiovascular risk factors are contradictory. HR and BP during rest and submaximal exercise are reduced after cessation of regular use of snuff. Evidently, the long-time adrenergic stress on circulation is reversible.

  8. Social Anxiety, Affect, Cortisol Response and Performance on a Speech Task.

    PubMed

    Losiak, Wladyslaw; Blaut, Agata; Klosowska, Joanna; Slowik, Natalia

    2016-01-01

    Social anxiety is characterized by increased emotional reactivity to social stimuli, but results of studies focusing on affective reactions of socially anxious subjects in the situation of social exposition are inconclusive, especially in the case of endocrinological measures of affect. This study was designed to examine individual differences in endocrinological and affective reactions to social exposure as well as in performance on a speech task in a group of students (n = 44) comprising subjects with either high or low levels of social anxiety. Measures of salivary cortisol and positive and negative affect were taken before and after an impromptu speech. Self-ratings and observer ratings of performance were also obtained. Cortisol levels and negative affect increased in both groups after the speech task, and positive affect decreased; however, group × affect interactions were not significant. Assessments conducted after the speech task revealed that highly socially anxious participants had lower observer ratings of performance while cortisol increase and changes in self-reported affect were not related to performance. Socially anxious individuals do not differ from nonanxious individuals in affective reactions to social exposition, but reveal worse performance at a speech task. © 2015 S. Karger AG, Basel.

  9. Do Cognitive Styles Affect the Performance of System Development Groups?

    DTIC Science & Technology

    1986-03-21

    shows that creativity is strongly associated with the Intuitive dimension. Sensing types are rarely found in fields associated with research or creative ... activities . [Ref. 15: p. 351 Slocum [Ref. 191 found clear differences in change agent strategies. The Sensing-Thinker’s overall preferred strategy is

  10. Factors affecting the performance of professional nurses in Namibia.

    PubMed

    Awases, Magdalene H; Bezuidenhout, Marthie C; Roos, Janetta H

    2013-04-19

    Professional nurses play a vital role in the provision of health care globally. The performance of health care workers, including professional nurses, link closely to the productivity and quality of care provision within health care organisations. It was important to identify factors influencing the performance of professional nurses if the quality of health care delivery was to improved. The aim of the present study was to identify factors affecting the performance of professional nurses in Namibia. A quantitative, descriptive survey was used to collect data by means of a questionnaire. A random sample of 180 professional nurses was selected from six hospitals in three regions of Namibia. Factors affecting the performance of nurses negatively were identified such as: lack of recognition of employees who are performing well, quality performance outcomes and an absence of a formal performance appraisal system and poor working conditions. Various factors contribute to both the positive and negative performance of professional nurses in Namibia. Strategies were developed for addressing the negative factors that could positively affect the performance of professional nurses in Namibia. This study emphasises the importance of developing strategies to promote the performance of nurses; build knowledge and expertise; develop mechanisms for improving the performance of nurses; expand leadership and management capacity; and generate information and knowledge through research.

  11. 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…

  12. 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,…

  13. 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…

  14. Perceptual grouping affects pitch judgments across time and frequency.

    PubMed

    Borchert, Elizabeth M O; Micheyl, Christophe; Oxenham, Andrew J

    2011-02-01

    Pitch, the perceptual correlate of fundamental frequency (F0), plays an important role in speech, music, and animal vocalizations. Changes in F0 over time help define musical melodies and speech prosody, while comparisons of simultaneous F0 are important for musical harmony, and for segregating competing sound sources. This study compared listeners' ability to detect differences in F0 between pairs of sequential or simultaneous tones that were filtered into separate, nonoverlapping spectral regions. The timbre differences induced by filtering led to poor F0 discrimination in the sequential, but not the simultaneous, conditions. Temporal overlap of the two tones was not sufficient to produce good performance; instead performance appeared to depend on the two tones being integrated into the same perceptual object. The results confirm the difficulty of comparing the pitches of sequential sounds with different timbres and suggest that, for simultaneous sounds, pitch differences may be detected through a decrease in perceptual fusion rather than an explicit coding and comparison of the underlying F0s.

  15. [Job performance in work organizations: the effects of management by group goals and job interdependence].

    PubMed

    Ikeda, Hiroshi; Furukawa, Hisataka

    2015-04-01

    cThis study examined the interactive effect of management by group goals and job interdependence on employee's activities in terms of task and contextual performance. A survey was conducted among 140 Japanese employees. Results indicated that management by group goals was related only to contextual performance. Job interdependence, however, had a direct effect on both task and contextual performance. Moreover, moderated regression analyses revealed that for work groups requiring higher interdependence among employees, management by group goals had a positive relation to contextual performance but not to task performance. When interdependence was not necessarily required, however, management by group goals had no relation to contextual performance and even negatively impacted task performance, respectively. These results show that management by group goals affects task and contextual performance, and that this effect is moderated by job interdependence. This provides a theoretical extension as well as a practical application to the setting and management of group goals.

  16. Grouping of contextual elements that affect vernier thresholds.

    PubMed

    Malania, Maka; Herzog, Michael H; Westheimer, Gerald

    2007-01-29

    To reveal the mechanisms of spatial interference in the fovea, we examined the capacity of a variety of lateral flanking configurations to interfere with alignment thresholds of a vertical vernier. A single line on each side of the vernier, at the optimal separation of 2-3 arcmin, raises thresholds threefold or more and masks most effectively when its length equals that of the vernier. For an array of equal lines whose length differs from that of the vernier, masking is reduced but not when vernier and flanks have the same length. The reduction for shorter and longer flanks can be reversed by inserting a gap in the row of flanks. By comparing the masking effect of arrays of mixed line lengths, we show that when a pair of flanks, which by itself masks strongly, becomes a component of a coherent contextual configuration, it loses much of its effectiveness to interact. Observers' ranking of the conspicuity of the vernier test pattern among the flanking elements is negatively correlated with the threshold elevation. We conclude that clustering of contextual patterns influences their capacity to mask. Discrimination of a target deteriorates when the target is grouped within an array of surrounding elements.

  17. Effects of Oxygen-Containing Functional Groups on Supercapacitor Performance

    SciTech Connect

    Kerisit, Sebastien N.; Schwenzer, Birgit; Vijayakumar, M.

    2014-07-03

    Molecular dynamics (MD) simulations of the interface between graphene and the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIM OTf) were carried out to gain molecular-level insights into the performance of graphene-based supercapacitors and, in particular, determine the effects of the presence of oxygen-containing defects at the graphene surface on their integral capacitance. The MD simulations predict that increasing the surface coverage of hydroxyl groups negatively affects the integral capacitance, whereas the effect of the presence of epoxy groups is much less significant. The calculated variations in capacitance are found to be directly correlated to the interfacial structure. Indeed, hydrogen bonding between hydroxyl groups and SO3 anion moieties prevents BMIM+ and OTf- molecules from interacting favorably in the dense interfacial layer and restrains the orientation and mobility of OTf- ions, thereby reducing the permittivity of the ionic liquid at the interface. The results of the molecular simulations can facilitate the rational design of electrode materials for supercapacitors.

  18. Performing a secondary executive task with affective stimuli interferes with decision making under risk conditions.

    PubMed

    Gathmann, Bettina; Pawlikowski, Mirko; Schöler, Tobias; Brand, Matthias

    2014-05-01

    Previous studies demonstrated that executive functions are crucial for advantageous decision making under risk and that therefore decision making is disrupted when working memory capacity is demanded while working on a decision task. While some studies also showed that emotions can affect decision making under risk, it is unclear how affective processing and executive functions predict decision-making performance in interaction. The current experimental study used a between-subjects design to examine whether affective pictures (positive and negative pictures compared to neutral pictures), included in a parallel executive task (working memory 2-back task), have an impact on decision making under risk as assessed by the Game of Dice Task (GDT). Moreover, the performance GDT plus 2-back task was compared to the performance in the GDT without any additional task (GDT solely). The results show that the performance in the GDT differed between groups (positive, negative, neutral, and GDT solely). The groups with affective pictures, especially those with positive pictures in the 2-back task, showed more disadvantageous decisions in the GDT than the groups with neutral pictures and the group performing the GDT without any additional task. However, executive functions moderated the effect of the affective pictures. Regardless of affective influence, subjects with good executive functions performed advantageously in the GDT. These findings support the assumption that executive functions and emotional processing interact in predicting decision making under risk.

  19. Individual Learning and Group Performance: The Role of Collective Efficacy

    ERIC Educational Resources Information Center

    Budworth, Marie-Helene

    2011-01-01

    Purpose: The aim of the current study is to investigate the effect of training individual group members on the collective efficacy of the group and the group's subsequent performance. Design/methodology/approach: Participants (n = 275), in a laboratory study were randomly assigned to groups of five (k = 55). Individuals were then randomly selected…

  20. Predicting performance expectations from affective impressions: linking affect control theory and status characteristics theory.

    PubMed

    Dippong, Joseph; Kalkhoff, Will

    2015-03-01

    Affect control theory (ACT) and status characteristics theory (SCT) offer separate and distinct explanations for how individuals interpret and process status- and power-relevant information about interaction partners. Existing research within affect control theory offers evidence that status and power are related to the affective impressions that individuals form of others along the dimensions of evaluation and potency, respectively. Alternately, status characteristics theory suggests that status and power influence interaction through the mediating cognitive construct of performance expectations. Although both theories have amassed an impressive amount of empirical support, research has yet to articulate theoretical and empirical connections between affective impressions and performance expectations. The purpose of our study is to address this gap. Elaborating a link between ACT and SCT in terms of their central concepts can serve as a stepping stone to improving the explanatory capacity of both theories, while providing a potential bridge by which they can be employed jointly.

  1. 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.

  2. Understanding Group and Leader (UGL) trainers' personality characteristics and affective profiles

    PubMed Central

    Rapp Ricciardi, Max; Åkerman, Jeanette; Eerikäinen, Peter; Ambjörnsson, Annika; Andersson Arntén, Ann-Christine; Mihailovic, Marko; Archer, Trevor; Garcia, Danilo

    2014-01-01

    Background: The Understanding Group and Leader (UGL), provided by the Swedish National Defense College and mentored by UGL-trainers, is one of the most popular management programs among civilians in Sweden. However, there is a lack of scientific evidence regarding the training. We used the affective profile model (i.e., the combination of positive, PA, and negative affect, NA) to mapp important markers of empowerment, self-awareness, adaptive coping skills, and maturity among the UGL-trainers. The aims were: (1) to compare profiles between UGL-trainers and managers/supervisors and (2) to investigate differences in personal characteristics. Method: UGL-trainers (N = 153) and the comparison group (104 Swedish Chiefs of Police) completed an online survey on optimism, self-esteem, locus of control, and affect. The four profiles are: self-fulfilling (high PA, low NA), high affective (high PA, high NA), low affective (high PA, low NA), and self-destructive (low PA, high NA). Results: The self-fulfilling profile was more common among UGL-trainers (25.70%) than among Chiefs of Police (19.20%). UGL-trainers, compared to Chiefs of Police, were more likely to express a self-fulling than a low affective profile (OR = 2.22, p < 0.05) and a high affective than a low affective profile (OR = 1.43, p < 0.001). UGL-trainers with a self-fulfilling profile, compared to those with a self-destructive profile, scored higher in optimism, higher in self-esteem, and lower in external locus of control. Conclusions: The probability of self-fulfillment rather than low affectivity was higher among UGL-trainers. Self-fulfillment was associated to markers of self-awareness and adaptive coping skills. However, the most common profile was the low affective, which is associated to low performance during stress, low degree of personal development, low degree of purpose in life, and low resilience. Hence, it might be important for UGL-trainers to have a continuous training in awareness after

  3. [The implications of a psychoeducation group on the everyday lives of individuals with bipolar affective disorder].

    PubMed

    Menezes, Sarita Lopes; de Mello E Souza, Maria Conceição Bernardo

    2012-02-01

    There is growing evidence that the course of Bipolar Affective Disorder (BAD) can be altered by psychotherapeutic approaches, such as Psychoeducation. Therefore, this study was performed with the objective of identifying the implications of a Psychoeducation group on the everyday lives of individuals with BAD. To do this, the authors chose to perform a qualitative case study. Participants included twelve individuals with BAD who had attended at least six meetings of the Psychoeducation Group held at the São José do Rio Preto Faculty of Medicine (FAMERP). Semi-structured interviews were performed, which were recorded and then transcribed and subjected to Thematic Analysis. The present study showed that the referred group experience promoted the individuals' knowledge acquisition; their awareness regarding the disease and adherence to treatment; their making positive changes in life; the possibility of helping other patients to benefit from the knowledge learned in the group; and their awareness regarding other realities and coping strategies, obtained by exchanging experiences with other participants.

  4. Introduction of the UNIX International Performance Management Work Group

    NASA Technical Reports Server (NTRS)

    Newman, Henry

    1993-01-01

    In this paper we presented the planned direction of the UNIX International Performance Management Work Group. This group consists of concerned system developers and users who have organized to synthesize recommendations for standard UNIX performance management subsystem interfaces and architectures. The purpose of these recommendations is to provide a core set of performance management functions and these functions can be used to build tools by hardware system developers, vertical application software developers, and performance application software developers.

  5. Agreement in interpersonal perception as a predictor of group performance.

    PubMed

    Sierra, Vicenta; Andrés, Amara; Solanas, Antonio; Leiva, David

    2010-11-01

    The present work deals with quantifying group characteristics. Specifically, dyadic measures of interpersonal perceptions were used to forecast group performance. Forty-six groups of students, 24 of four and 22 of five people, were studied in a real educational assignment context and marks were gathered as an indicator of group performance. Our results show that dyadic measures of interpersonal perceptions account for final marks. By means of linear regression analysis, 85% and 85.6% of group performance, respectively, was explained for group sizes equal to four and five. Results found in the scientific literature based on the individualistic approach are no larger than 18%. The results of the present study support the utility of dyadic approaches for predicting group performance in social contexts.

  6. A Longitudinal Field Investigation of the Impact of Group Composition on Group Performance and Cohesion.

    ERIC Educational Resources Information Center

    Terborg, James R.; And Others

    In a longitudinal field experiment, 42 groups were assembled on the factors of individual ability and attitude similarity resulting in a 2 x 2 crossed ANOVA design. These groups then worked on six projects which spanned a three-month time period. For each project, measures of group performance and group cohesion were taken. Analyses showed that…

  7. 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…

  8. Sex, Affect, and Academic Performance: It's Not What You Think

    ERIC Educational Resources Information Center

    Lewine, Rich; Sommers, Alison; Waford, Rachel; Bustanoby, Heather; Robertson, Catherine; Hall, Rachel; Eisenmenger, Karen

    2011-01-01

    The academic impact of serious depression among college students is beginning to receive increased attention in the research literature. In contrast, we know very little about the affect of mild depression, or dysphoria, on academic performance. This study examines the relationship of baseline dysphoria in 188 students to five measures of academic…

  9. 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…

  10. 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…

  11. 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…

  12. 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.

  13. 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

  14. How motivation affects academic performance: a structural equation modelling analysis.

    PubMed

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

    2013-03-01

    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 Motivation (RAM, a measure of the balance between AM and CM) affects academic performance through good study strategy and higher study effort and compare this model between subgroups: males and females; students selected via two different systems namely qualitative and weighted lottery selection. Data on motivation, study strategy and effort was collected from 383 medical students of VU University Medical Center Amsterdam and their academic performance results were obtained from the student administration. Structural Equation Modelling analysis technique was used to test a hypothesized model in which high RAM would positively affect Good Study Strategy (GSS) and study effort, which in turn would positively affect academic performance in the form of grade point averages. This model fit well with the data, Chi square = 1.095, df = 3, p = 0.778, RMSEA model fit = 0.000. This model also fitted well for all tested subgroups of students. Differences were found in the strength of relationships between the variables for the different subgroups as expected. In conclusion, RAM positively correlated with academic performance through deep strategy towards study and higher study effort. This model seems valid in medical education in subgroups such as males, females, students selected by qualitative and weighted lottery selection.

  15. Preparatory power posing affects nonverbal presence and job interview performance.

    PubMed

    Cuddy, Amy J C; Wilmuth, Caroline A; Yap, Andy J; Carney, Dana R

    2015-07-01

    The authors tested whether engaging in expansive (vs. contractive) "power poses" before a stressful job interview--preparatory power posing--would enhance performance during the interview. Participants adopted high-power (i.e., expansive, open) poses or low-power (i.e., contractive, closed) poses, and then prepared and delivered a speech to 2 evaluators as part of a mock job interview. All interview speeches were videotaped and coded for overall performance and hireability and for 2 potential mediators: verbal content (e.g., structure, content) and nonverbal presence (e.g., captivating, enthusiastic). As predicted, those who prepared for the job interview with high- (vs. low-) power poses performed better and were more likely to be chosen for hire; this relation was mediated by nonverbal presence, but not by verbal content. Although previous research has focused on how a nonverbal behavior that is enacted during interactions and observed by perceivers affects how those perceivers evaluate and respond to the actor, this experiment focused on how a nonverbal behavior that is enacted before the interaction and unobserved by perceivers affects the actor's performance, which, in turn, affects how perceivers evaluate and respond to the actor. This experiment reveals a theoretically novel and practically informative result that demonstrates the causal relation between preparatory nonverbal behavior and subsequent performance and outcomes.

  16. Intergroup conflict, out-group derogation, and self-directed negative affect among Italian South Tyroleans.

    PubMed

    Costarelli, Sandro; Colloca, Pasquale

    2004-04-01

    In South Tyrol, a multiethnic Italian province, the authors examined the self-directed negative affect that members of an Italian group experienced after they evaluated members of the German and Albanian groups. The authors examined the affect as a function of out-group derogation. The authors argued that to the extent that out-group derogation may run counter to norms toward intergroup fairness, such normative nonconformity will elicit negative affect directed at the self as a function of perceived intergroup conflict. The findings support the authors' line of reasoning: among Italian South Tyroleans, those who expressed greater out-group derogation were led to experience stronger negative self-directed affect when they rated a low-conflict out-group, but not when they rated a high-conflict out-group, compared to participants whose out-group derogation was less.

  17. Cognitive, Affective, and Behavioral Effects of Reminiscence Group Therapy on Demented Elderly.

    ERIC Educational Resources Information Center

    Goldwasser, A. Norman; And Others

    1987-01-01

    Assigned 27 demented elderly nursing home residents to either reminiscence group therapy, supportive group therapy, or a no-treatment control group. Results showed the self-reported level of depression in participants given reminiscence therapy was positively affected compared with participants in the supportive therapy and control groups.…

  18. Cognitive, Affective, and Behavioral Effects of Reminiscence Group Therapy on Demented Elderly.

    ERIC Educational Resources Information Center

    Goldwasser, A. Norman; And Others

    1987-01-01

    Assigned 27 demented elderly nursing home residents to either reminiscence group therapy, supportive group therapy, or a no-treatment control group. Results showed the self-reported level of depression in participants given reminiscence therapy was positively affected compared with participants in the supportive therapy and control groups.…

  19. Group Performance Under Experienced and Inexperienced Leaders; A Validation Experiment.

    ERIC Educational Resources Information Center

    Fiedler, Fred E.; Chemers, Martin M.

    This study investigated the effect of experience and training on the performance of Belgian naval officers in an experimental leadership situation. As in a previous study conducted with Belgian naval personnel, group performance under trained and experienced officers was not significantly better than performance under untrained recruits. Moreover,…

  20. The multilevel analysis of surface acting and mental health: A moderation of positive group affective tone

    NASA Astrophysics Data System (ADS)

    Lee, Meng-Shiu; Huang, Jui-Chan; Wu, Tzu-Jung

    2017-06-01

    The purpose of this study is to investigate the relationship among surface acting, mental health, and positive group affective tone. According to the prior theory, this study attempts to establish a comprehensive research framework among these variables, and furthermore tests the moderating effect of positive group affective tone. Data were collected from 435 employees in 52 service industrial companies by questionnaire, and this study conducted multilevel analysis. The results showed that surface acting will negatively affect the mental health. In addition, the positive group affective tone have significant moderating effect on the relationship among surface acting and mental health. Finally, this study discusses managerial implications and highlights future research suggestions.

  1. Letting the Drama into Group Work: Using Conflict Constructively in Performing Arts Group Practice

    ERIC Educational Resources Information Center

    Crossley, Tracy

    2006-01-01

    The article examines conflict avoidance in performing arts group work and issues arising in relation to teaching and learning. In group theory, conflict is addressed largely in terms of its detrimental effects on group work, and its constructive potential is often marginalized. Similarly, undergraduate students usually interpret "effective…

  2. Letting the Drama into Group Work: Using Conflict Constructively in Performing Arts Group Practice

    ERIC Educational Resources Information Center

    Crossley, Tracy

    2006-01-01

    The article examines conflict avoidance in performing arts group work and issues arising in relation to teaching and learning. In group theory, conflict is addressed largely in terms of its detrimental effects on group work, and its constructive potential is often marginalized. Similarly, undergraduate students usually interpret "effective…

  3. Planning and Performance in Small Groups: Collective Implementation Intentions Enhance Group Goal Striving

    PubMed Central

    Thürmer, J. Lukas; Wieber, Frank; Gollwitzer, Peter M.

    2017-01-01

    There are two key motivators to perform well in a group: making a contribution that (a) is crucial for the group (indispensability) and that (b) the other group members recognize (identifiability). We argue that indispensability promotes setting collective (“We”) goals whereas identifiability induces individual (“I”) goals. Although both goals may enhance performance, they should align with different strategies. Whereas pursuing collective goals should involve more cooperation, pursuing individual goals should involve less cooperation. Two experiments support this reasoning and show that planning out collective goals with collective implementation intentions (cIIs or “We-plans”) relies on cooperation but planning out individual goals with individual implementation intentions (IIs or “I-plans”) does not. In Experiment 1, three-member groups first formed a collective or an individual goal and then performed a first round of a physical persistence task. Groups then either formed a respective implementation intention (cII or II) or a control plan and then performed a second round of the task. Although groups with cIIs and IIs performed better on a physical persistence task than respective control groups, only cII groups interacted more cooperatively during task performance. To confirm the causal role of these interaction processes, Experiment 2 used the same persistence task and manipulated whether groups could communicate: When communication was hindered, groups with cIIs but not groups with IIs performed worse. Communication thus qualifies as a process making cIIs effective. The present research offers a psychology of action account to small group performance. PMID:28469592

  4. 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.

  5. How does the grouping scheme affect the Wiener Filter reconstruction of the local Universe?

    NASA Astrophysics Data System (ADS)

    Sorce, Jenny G.; Tempel, Elmo

    2017-08-01

    High-quality reconstructions of the three-dimensional velocity and density fields of the local Universe are essential to study the local large scale structure. In this paper, the Wiener Filter reconstruction technique is applied to galaxy radial peculiar velocity catalogues to understand how the Hubble constant (H0) value and the grouping scheme affect the reconstructions. While H0 is used to derive radial peculiar velocities from galaxy distance measurements and total velocities, the grouping scheme serves the purpose of removing non-linear motions. Two different grouping schemes (based on the literature and a systematic algorithm) as well as five H0 values ranging from 72 to 76 km s-1 Mpc-1 are selected. The Wiener Filter is applied to the resulting catalogues. Whatever grouping scheme is used, the larger H0 is, the larger the infall on to the local volume is. However, this conclusion has to be strongly mitigated: a bias minimization scheme applied to the catalogues after grouping suppresses this effect. At fixed H0, reconstructions obtained with catalogues grouped with the different schemes exhibit structures at the proper location in both cases but the latter are more contrasted in the less aggressive scheme case: Having more constraints permits an infall from both sides on to the structures to reinforce their overdensity. Such findings highlight the importance of a balance between grouping to suppress non-linear motions and preserving constraints to produce an infall on to structures expected to be large overdensities. Such an observation is promising to perform constrained simulations of the local Universe, including its massive clusters.

  6. Binaural auditory beats affect vigilance performance and mood.

    PubMed

    Lane, J D; Kasian, S J; Owens, J E; Marsh, G R

    1998-01-01

    When two tones of slightly different frequency are presented separately to the left and right ears the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones, a perceptual phenomenon known as the binaural auditory beat. Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published. This study compared the effects of binaural auditory beats in the EEG beta and EEG theta/delta frequency ranges on mood and on performance of a vigilance task to investigate their effects on subjective and objective measures of arousal. Participants (n = 29) performed a 30-min visual vigilance task on three different days while listening to pink noise containing simple tones or binaural beats either in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4 Hz). However, participants were kept blind to the presence of binaural beats to control expectation effects. Presentation of beta-frequency binaural beats yielded more correct target detections and fewer false alarms than presentation of theta/delta frequency binaural beats. In addition, the beta-frequency beats were associated with less negative mood. Results suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of human performance.

  7. Dynamic Task Performance, Cohesion, and Communications in Human Groups.

    PubMed

    Giraldo, Luis Felipe; Passino, Kevin M

    2016-10-01

    In the study of the behavior of human groups, it has been observed that there is a strong interaction between the cohesiveness of the group, its performance when the group has to solve a task, and the patterns of communication between the members of the group. Developing mathematical and computational tools for the analysis and design of task-solving groups that are not only cohesive but also perform well is of importance in social sciences, organizational management, and engineering. In this paper, we model a human group as a dynamical system whose behavior is driven by a task optimization process and the interaction between subsystems that represent the members of the group interconnected according to a given communication network. These interactions are described as attractions and repulsions among members. We show that the dynamics characterized by the proposed mathematical model are qualitatively consistent with those observed in real-human groups, where the key aspect is that the attraction patterns in the group and the commitment to solve the task are not static but change over time. Through a theoretical analysis of the system we provide conditions on the parameters that allow the group to have cohesive behaviors, and Monte Carlo simulations are used to study group dynamics for different sets of parameters, communication topologies, and tasks to solve.

  8. Effects of self-efficacy, affectivity and collective efficacy on nursing performance of hospital nurses.

    PubMed

    Lee, Tae Wha; Ko, Yu Kyung

    2010-04-01

    This paper is a report of a study conducted to examine the influence of self-efficacy and affectivity (individual-level variables) and collective efficacy (group-level variable) on nursing performance among hospital nurses. Previous studies of nursing performance, which have focused on individual factor outcomes, have shown limitations. Due to the heavy focus on the analysis of single-level performances, the influence of organizational contextual factors on nursing performance has rarely been studied. Hence, for a better understanding of nurses' professional development and effective functioning in hospitals, there is a need to study the effects of organizational characteristics as well as individual characteristics on nursing performance. A descriptive-correlational design was used with a convenience sample of 1996 nurses selected from 182 nursing units in 28 hospitals in six metropolitan cities and seven provinces in Korea. Data were collected in 2006 using self-administered questionnaires, which were analysed with using descriptive statistics, Pearson correlation coefficients and multilevel analysis. Individual-level variables, including job position, years of experience, employment status, self-efficacy and positive affectivity were positively related to nursing performance. Collective efficacy and the number of in-service meetings within units were statistically significant group-level variables. Group-level variables reduced the error variances in nursing performance. Understanding the effects of group-level variables on nursing performance improves performance management approaches in hospitals.

  9. 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.

  10. Performance pressure and caffeine both affect cognitive performance, but likely through independent mechanisms.

    PubMed

    Boere, Julia J; Fellinger, Lizz; Huizinga, Duncan J H; Wong, Sebastiaan F; Bijleveld, Erik

    2016-02-01

    A prevalent combination in daily life, performance pressure and caffeine intake have both been shown to impact people's cognitive performance. Here, we examined the possibility that pressure and caffeine affect cognitive performance via a shared pathway. In an experiment, participants performed a modular arithmetic task. Performance pressure and caffeine intake were orthogonally manipulated. Findings indicated that pressure and caffeine both negatively impacted performance. However, (a) pressure vs. caffeine affected performance on different trial types, and (b) there was no hint of an interactive effect. So, though the evidence is indirect, findings suggest that pressure and caffeine shape performance via distinct mechanisms, rather than a shared one. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Error framing effects on performance: cognitive, motivational, and affective pathways.

    PubMed

    Steele-Johnson, Debra; Kalinoski, Zachary T

    2014-01-01

    Our purpose was to examine whether positive error framing, that is, making errors salient and cuing individuals to see errors as useful, can benefit learning when task exploration is constrained. Recent research has demonstrated the benefits of a newer approach to training, that is, error management training, that includes the opportunity to actively explore the task and framing errors as beneficial to learning complex tasks (Keith & Frese, 2008). Other research has highlighted the important role of errors in on-the-job learning in complex domains (Hutchins, 1995). Participants (N = 168) from a large undergraduate university performed a class scheduling task. Results provided support for a hypothesized path model in which error framing influenced cognitive, motivational, and affective factors which in turn differentially affected performance quantity and quality. Within this model, error framing had significant direct effects on metacognition and self-efficacy. Our results suggest that positive error framing can have beneficial effects even when tasks cannot be structured to support extensive exploration. Whereas future research can expand our understanding of error framing effects on outcomes, results from the current study suggest that positive error framing can facilitate learning from errors in real-time performance of tasks.

  12. When does power disparity help or hurt group performance?

    PubMed

    Tarakci, Murat; Greer, Lindred L; Groenen, Patrick J F

    2016-03-01

    Power differences are ubiquitous in social settings. However, the question of whether groups with higher or lower power disparity achieve better performance has thus far received conflicting answers. To address this issue, we identify 3 underlying assumptions in the literature that may have led to these divergent findings, including a myopic focus on static hierarchies, an assumption that those at the top of hierarchies are competent at group tasks, and an assumption that equality is not possible. We employ a multimethod set of studies to examine these assumptions and to understand when power disparity will help or harm group performance. First, our agent-based simulation analyses show that by unpacking these common implicit assumptions in power research, we can explain earlier disparate findings--power disparity benefits group performance when it is dynamically aligned with the power holder's task competence, and harms group performance when held constant and/or is not aligned with task competence. Second, our empirical findings in both a field study of fraud investigation groups and a multiround laboratory study corroborate the simulation results. We thereby contribute to research on power by highlighting a dynamic understanding of power in groups and explaining how current implicit assumptions may lead to opposing findings.

  13. Management behavior, group climate and performance appraisal at NASA

    NASA Technical Reports Server (NTRS)

    Manderlink, G.; Clark, L. P.; Bernstein, W. M.; Burke, W. W.

    1985-01-01

    The relationships among manager behavior, group climate and managerial effectiveness are examined. Survey data were collected from 435 GM14-15 managers and their subordinates at NASA concerning management practices and perceptions of the group environment. Performance ratings of managers were obtained from their superiors. The results strongly supported a causal model in which subordinates' climate perceptions mediate the effects of manager behavior on performance. That is, the development of group climate provides the process through which the effects of manager practices may be understood. Analyses also revealed that the function performed by a manager and his group (e.g., research) influenced the specific nature of the causal dynamics. Some implications of the results for management training and development are discussed.

  14. Management behavior, group climate and performance appraisal at NASA

    NASA Technical Reports Server (NTRS)

    Manderlink, G.; Clark, L. P.; Bernstein, W. M.; Burke, W. W.

    1985-01-01

    The relationships among manager behavior, group climate and managerial effectiveness are examined. Survey data were collected from 435 GM14-15 managers and their subordinates at NASA concerning management practices and perceptions of the group environment. Performance ratings of managers were obtained from their superiors. The results strongly supported a causal model in which subordinates' climate perceptions mediate the effects of manager behavior on performance. That is, the development of group climate provides the process through which the effects of manager practices may be understood. Analyses also revealed that the function performed by a manager and his group (e.g., research) influenced the specific nature of the causal dynamics. Some implications of the results for management training and development are discussed.

  15. Does familiarity with computers affect computerized neuropsychological test performance?

    PubMed

    Iverson, Grant L; Brooks, Brian L; Ashton, V Lynn; Johnson, Lynda G; Gualtieri, C Thomas

    2009-07-01

    The purpose of this study was to determine whether self-reported computer familiarity is related to performance on computerized neurocognitive testing. Participants were 130 healthy adults who self-reported whether their computer use was "some" (n = 65) or "frequent" (n = 65). The two groups were individually matched on age, education, sex, and race. All completed the CNS Vital Signs (Gualtieri & Johnson, 2006b) computerized neurocognitive battery. There were significant differences on 6 of the 23 scores, including scores derived from the Symbol-Digit Coding Test, Stroop Test, and the Shifting Attention Test. The two groups were also significantly different on the Psychomotor Speed (Cohen's d = 0.37), Reaction Time (d = 0.68), Complex Attention (d = 0.40), and Cognitive Flexibility (d = 0.64) domain scores. People with "frequent" computer use performed better than people with "some" computer use on some tests requiring rapid visual scanning and keyboard work.

  16. 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.

  17. Group Random Call Can Positively Affect Student In-Class Clicker Discussions

    PubMed Central

    Knight, Jennifer K.; Wise, Sarah B.; Sieke, Scott

    2016-01-01

    Understanding how instructional techniques and classroom norms influence in-class student interactions has the potential to positively impact student learning. Many previous studies have shown that students benefit from discussing their ideas with one another in class. In this study of introductory biology students, we explored how using an in-class accountability system might affect the nature of clicker-question discussions. Clicker-question discussions in which student groups were asked to report their ideas voluntarily (volunteer call) were compared with discussions in which student groups were randomly selected to report their ideas (random call). We hypothesized that the higher-accountability condition (random call) would impress upon students the importance of their discussions and thus positively influence how they interacted. Our results suggest that a higher proportion of discussions in the random call condition contained exchanges of reasoning, some forms of questioning, and both on- and off-topic comments compared with discussion in the volunteer call condition. Although group random call does not impact student performance on clicker questions, the positive impact of this instructional approach on exchanges of reasoning and other features suggests it may encourage some types of student interactions that support learning. PMID:27856544

  18. Group Random Call Can Positively Affect Student In-Class Clicker Discussions.

    PubMed

    Knight, Jennifer K; Wise, Sarah B; Sieke, Scott

    2016-01-01

    Understanding how instructional techniques and classroom norms influence in-class student interactions has the potential to positively impact student learning. Many previous studies have shown that students benefit from discussing their ideas with one another in class. In this study of introductory biology students, we explored how using an in-class accountability system might affect the nature of clicker-question discussions. Clicker-question discussions in which student groups were asked to report their ideas voluntarily (volunteer call) were compared with discussions in which student groups were randomly selected to report their ideas (random call). We hypothesized that the higher-accountability condition (random call) would impress upon students the importance of their discussions and thus positively influence how they interacted. Our results suggest that a higher proportion of discussions in the random call condition contained exchanges of reasoning, some forms of questioning, and both on- and off-topic comments compared with discussion in the volunteer call condition. Although group random call does not impact student performance on clicker questions, the positive impact of this instructional approach on exchanges of reasoning and other features suggests it may encourage some types of student interactions that support learning.

  19. Tail regeneration affects the digestive performance of a Mediterranean lizard

    NASA Astrophysics Data System (ADS)

    Sagonas, Kostas; Karambotsi, Niki; Bletsa, Aristoula; Reppa, Aikaterini; Pafilis, Panayiotis; Valakos, Efstratios D.

    2017-04-01

    In caudal autotomy, lizards shed their tail to escape from an attacking predator. Since the tail serves multiple functions, caudal regeneration is of pivotal importance. However, it is a demanding procedure that requires substantial energy and nutrients. Therefore, lizards have to increase energy income to fuel the extraordinary requirements of the regenerating tail. We presumed that autotomized lizards would adjust their digestion to acquire this additional energy. To clarify the effects of tail regeneration on digestion, we compared the digestive performance before autotomy, during regeneration, and after its completion. Tail regeneration indeed increased gut passage time but did not affect digestive performance in a uniform pattern: though protein income was maximized, lipid and sugar acquisition remained stable. This divergence in proteins may be attributed to their particular role in tail reconstruction, as they are the main building blocks for tissue formation.

  20. 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

  1. Can small shifts in circadian phase affect performance?

    PubMed

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

    2013-01-01

    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 h shift away from a proposed optimal circadian phase angle (6 h 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.

  2. Temporary versus permanent group membership: how the future prospects of newcomers affect newcomer acceptance and newcomer influence.

    PubMed

    Rink, Floor A; Ellemers, Naomi

    2009-06-01

    Three studies examine how the future prospects of new group members affect newcomer acceptance and newcomer influence. In Study 1, participants anticipate accepting temporary newcomers less easily than permanent newcomers because they expect temporary newcomers to differ from the group. In Study 2, the effects of newcomer entry in three-person groups are examined. Results show that groups perceived temporary newcomers as more involved in a judgmental decision-making process than permanent newcomers. In Study 3, a hidden profile task confirms that temporary newcomers indeed shared more unique knowledge during discussions than permanent newcomers and that this enhanced the groups' decision quality. However, compared to permanent newcomers, temporary newcomers caused teams to experience more conflict and less group identification, illustrating the tension between innovative group performance and group cohesion. The results are discussed in light of the social identity perspective and research on minority influence.

  3. Rapid weight loss followed by recovery time does not affect judo-related performance.

    PubMed

    Artioli, Guilherme G; Iglesias, Rodrigo T; Franchini, Emerson; Gualano, Bruno; Kashiwagura, Daniel B; Solis, Marina Y; Benatti, Fabiana B; Fuchs, Marina; Lancha Junior, Antonio H

    2010-01-01

    In this study, we investigated the effects of rapid weight loss followed by a 4-h recovery on judo-related performance. Seven weight-cycler athletes were assigned to a weight loss group (5% body weight reduction by self-selected regime) and seven non-weight-cyclers to a control group (no weight reduction). Body composition, performance, glucose, and lactate were assessed before and after weight reduction (5-7 days apart; control group kept weight stable). The weight loss group had 4 h to re-feed and rehydrate after the weigh-in. Food intake was recorded during the weight loss period and recovery after the weigh-in. Performance was evaluated through a specific judo exercise, followed by a 5-min judo combat and by three bouts of the Wingate test. Both groups significantly improved performance after the weight loss period. No interaction effects were observed. The energy and macronutrient intake of the weight loss group were significantly lower than for the control group. The weight loss group consumed large amounts of food and carbohydrate during the 4-h recovery period. No changes were observed in lactate concentration, but a significant decrease in glucose during rest was observed in the weight loss group. In conclusion, rapid weight loss did not affect judo-related performance in experienced weight-cyclers when the athletes had 4 h to recover. These results should not be extrapolated to inexperienced weight-cyclers.

  4. Wheat gluten hydrolysate affects race performance in the triathlon.

    PubMed

    Koikawa, Natsue; Aoki, Emi; Suzuki, Yoshio; Sakuraba, Keishoku; Nagaoka, Isao; Aoki, Kazuhiro; Shimmura, Yuki; Sawaki, Keisuke

    2013-07-01

    Wheat gluten hydrolysate (WGH) is a food ingredient, prepared by partial enzymatic digestion of wheat gluten, which has been reported to suppress exercise-induced elevation of serum creatinine kinase (CK) activity. However, its effects on athletic performance have not yet been elucidated. This is the presentation of an experiment performed on five female college triathletes who completed an Olympic distance triathlon with or without ingestion of 21 g of WGH during the cycling leg. The experiment was performed in a crossover double-blind manner. The race time of the running leg and thus the total race time was significantly shorter when WGH was ingested. However, serum CK levels exhibited no apparent differences between the two WGH or placebo groups.

  5. The effect of affective bibliotherapy on clients' functioning in group therapy.

    PubMed

    Shechtman, Zipora; Nir-Shfrir, Rivka

    2008-01-01

    Abstract The effect of affective group bibliotherapy (GB) was compared to affective group therapy (GT) on patients' functioning in therapy and their session impression. Three small groups totaling twenty-five in-patients in a hospital in Israel participated in the study. Clients concurrently participated in both group types, undergoing three sessions in each condition. In-therapy behaviors were assessed through the Client Behavior System (CBS; Hill & O'Brien, 1999). Results indicated that in the GB condition compared to the GT condition, clients showed less resistance, used simple responses less frequently, and expressed greater affective exploration. The Session Evaluation Questionnaire (SEQ; Stiles et al., 1994) was used to measure clients' impressions of the sessions. Results indicated that patients evaluated the two treatment conditions equally. Overall, the results support earlier findings, suggesting that affective bibliotherapy can be an effective method of treatment.

  6. Diet quality affects bait performance in German cockroaches (Dictyoptera: Blattellidae).

    PubMed

    Ko, Alexander E; Schal, Coby; Silverman, Jules

    2016-10-01

    Bait formulations are widely used to control German cockroach (Blattella germanica) populations. To perform optimally, these formulations must compete favorably with non-toxic alternative foods present within the insect's habitat. We hypothesized that the nutritional history of cockroaches and their acceptance or avoidance of glucose would affect their food preference and thus bait efficacy. To test this hypothesis, we conducted a controlled laboratory experiment, first providing glucose-accepting and glucose-averse cockroaches nutritionally defined diets and then offering them identical diets containing the insecticide hydramethylnon as a bait proxy to evaluate the effect of diets of differing macronutrient composition on bait performance. The interaction between diet composition and bait composition affected the survival of adult males as well as first-instar nymphs exposed to excretions produced by these males. Survival analyses indicated different responses of glucose-averse and glucose-accepting insects, but generally any combination of diet and bait that resulted in high diet intake and low bait intake reduced secondary kill. This study represents a comprehensive examination of the effect of alternative foods on bait efficacy. We suggest that disparities between the nutritional quality of baits and the foods that are naturally available could profoundly impact the management of German cockroach infestations. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. When attention wanders: how uncontrolled fluctuations in attention affect performance.

    PubMed

    Cohen, Marlene R; Maunsell, John H R

    2011-11-02

    No matter how hard subjects concentrate on a task, their minds wander (Raichle et al., 2001; Buckner et al., 2008; Christoff et al., 2009; Killingsworth and Gilbert, 2010). Internal fluctuations cannot be measured behaviorally or from conventional neurophysiological measures, so their effects on performance have been difficult to study. Previously, we measured fluctuations in visual attention using the responses of populations of simultaneously recorded neurons in macaque visual cortex (Cohen and Maunsell, 2010). Here, we use this ability to investigate how attentional fluctuations affect performance. We found that attentional fluctuations have large and complex effects on performance, the sign of which depends on the difficulty of the perceptual judgment. As expected, attention greatly improves the detection of subtle changes in a stimulus. Surprisingly, we found that attending too strongly to a particular stimulus impairs the ability to notice when that stimulus changes dramatically. Our results suggest that all previously reported measures of behavioral performance should be viewed as amalgamations of different attentional states, whether or not those studies specifically addressed attention.

  8. Performance and consistency of indicator groups in two biodiversity hotspots.

    PubMed

    Trindade-Filho, Joaquim; Loyola, Rafael Dias

    2011-01-01

    In a world limited by data availability and limited funds for conservation, scientists and practitioners must use indicator groups to define spatial conservation priorities. Several studies have evaluated the effectiveness of indicator groups, but still little is known about the consistency in performance of these groups in different regions, which would allow their a priori selection. We systematically examined the effectiveness and the consistency of nine indicator groups in representing mammal species in two top-ranked Biodiversity Hotspots (BH): the Brazilian Cerrado and the Atlantic Forest. To test for group effectiveness we first found the best sets of sites able to maximize the representation of each indicator group in the BH and then calculated the average representation of different target species by the indicator groups in the BH. We considered consistent indicator groups whose representation of target species was not statistically different between BH. We called effective those groups that outperformed the target-species representation achieved by random sets of species. Effective indicator groups required the selection of less than 2% of the BH area for representing target species. Restricted-range species were the most effective indicators for the representation of all mammal diversity as well as target species. It was also the only group with high consistency. We show that several indicator groups could be applied as shortcuts for representing mammal species in the Cerrado and the Atlantic Forest to develop conservation plans, however, only restricted-range species consistently held as the most effective indicator group for such a task. This group is of particular importance in conservation planning as it captures high diversity of endemic and endangered species.

  9. The Impact of Perceived Loafing and Collective Efficacy on Group Goal Processes and Group Performance.

    PubMed

    Mulvey; Klein

    1998-04-01

    This paper presents two studies investigating the influence of social perceptions (perceived loafing, collective efficacy, and cohesion) on group goal processes (difficulty and commitment) and group performance. The role of group goal processes as mediators of the relationships between social perception variables and group performance was also tested. The first study involved a sample of 247 college students in 59 groups working on a team interdependent, divisible academic task. Results supported all but one hypothesis. The mediation hypothesis was not supported as both group goal and social perception variables related similarly to group performance. The second study employed a different design to address some limitations of the first study and to extend those findings. Results from the second study, using 383 college students in 101 groups, were consistent with Study 1 with two exceptions. First, the mediation hypothesis was supported in Study 2, replicating the findings of Klein and Mulvey (1995). Second, anticipated lower effort and the sucker effect, additional intervening variables examined in Study 2, partially mediated the relationship between perceived loafing and collective goal difficulty as hypothesized. Copyright 1998 Academic Press.

  10. Effects of Sequences of Cognitions on Group Performance Over Time

    PubMed Central

    Molenaar, Inge; Chiu, Ming Ming

    2017-01-01

    Extending past research showing that sequences of low cognitions (low-level processing of information) and high cognitions (high-level processing of information through questions and elaborations) influence the likelihoods of subsequent high and low cognitions, this study examines whether sequences of cognitions are related to group performance over time; 54 primary school students (18 triads) discussed and wrote an essay about living in another country (32,375 turns of talk). Content analysis and statistical discourse analysis showed that within each lesson, groups with more low cognitions or more sequences of low cognition followed by high cognition added more essay words. Groups with more high cognitions, sequences of low cognition followed by low cognition, or sequences of high cognition followed by an action followed by low cognition, showed different words and sequences, suggestive of new ideas. The links between cognition sequences and group performance over time can inform facilitation and assessment of student discussions. PMID:28490854

  11. Chronic Ankle Instability Does Not Affect Lower Extremity Functional Performance.

    PubMed

    Demeritt, Kerry M; Shultz, Sandra J; Docherty, Carrie L; Gansneder, Bruce M; Perrin, David H

    2002-12-01

    OBJECTIVE: To determine if functional performance is impaired in individuals with self-reported chronic ankle instability. DESIGN AND SETTING: We used a between-groups design to assess 3 functional variables. All data were collected at a Division III college and a military academy. Before testing, all subjects performed a 5-minute warm-up, followed by a series of stretches for the lower extremity muscles. Subjects then performed cocontraction, shuttle run, and agility hop tests in a counterbalanced fashion. Three trials for each functional test were completed and averaged for analysis. SUBJECTS: Twenty men with a history of at least 1 significant ankle sprain and episodes of at least 1 repeated ankle injury or feelings of instability or "giving way" were compared with 20 men with no prior history of ankle injury. Subjects were matched by age, height, weight, and activity level. MEASUREMENTS: Time to completion was measured in seconds for the cocontraction and the shuttle run tests. The agility hop test was measured on an error point scale. RESULTS: Using 3 separate, independent, 2-tailed t tests, we found no significant difference between groups for the cocontraction (P =.452), shuttle run (P =.680), or agility hop (P =.902) tests. CONCLUSIONS: Chronic ankle instability is a subjectively reported phenomenon defined as the tendency to "give way" during normal activity. Although athletes commonly complain of subjective symptoms associated with chronic ankle instability, our findings suggest that these symptoms do not negatively influence actual functional performance. Future researchers should evaluate other, more demanding functional-performance tests to further substantiate these findings.

  12. 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.

  13. The science of cycling: factors affecting performance - part 2.

    PubMed

    Faria, Erik W; Parker, Daryl L; Faria, Irvin E

    2005-01-01

    This review presents information that is useful to athletes, coaches and exercise scientists in the adoption of exercise protocols, prescription of training regimens and creation of research designs. Part 2 focuses on the factors that affect cycling performance. Among those factors, aerodynamic resistance is the major resistance force the racing cyclist must overcome. This challenge can be dealt with through equipment technological modifications and body position configuration adjustments. To successfully achieve efficient transfer of power from the body to the drive train of the bicycle the major concern is bicycle configuration and cycling body position. Peak power output appears to be highly correlated with cycling success. Likewise, gear ratio and pedalling cadence directly influence cycling economy/efficiency. Knowledge of muscle recruitment throughout the crank cycle has important implications for training and body position adjustments while climbing. A review of pacing models suggests that while there appears to be some evidence in favour of one technique over another, there remains the need for further field research to validate the findings. Nevertheless, performance modelling has important implications for the establishment of performance standards and consequent recommendations for training.

  14. 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.

  15. Investigating the Effects of Sweat Therapy on Group Dynamics and Affect

    ERIC Educational Resources Information Center

    Colmant, Stephen A.; Eason, Evan A.; Winterowd, Carrie L.; Jacobs, Sue C.; Cashel, Chris

    2005-01-01

    In this study, we examined the effects of sweat therapy on group dynamics and affect. Sweat therapy is the combination of intense heat exposure with psychotherapy or counseling (Colmant & Merta, 1999; 2000). Twenty-four undergraduates were separated by sex and randomly assigned to eight sessions of either a sweat or non-sweat group counseling…

  16. Parents' job insecurity affects children's academic performance through cognitive difficulties.

    PubMed

    Barling, J; Zacharatos, A; Hepburn, C G

    1999-06-01

    The authors developed and tested a model in which children who perceive their parents to be insecure about their jobs are distracted cognitively, which in turn affects their academic performance negatively. Participants were 102 female and 18 male undergraduates (mean age = 18 years), their fathers (mean age = 49 years), and their mothers (mean age = 47 years). Students completed questionnaires measuring perceived parental job insecurity, identification with parents, and cognitive difficulties; 3 months later, they also reported their midyear grades. Fathers and mothers each completed questionnaires assessing their job insecurity. Support for the model was obtained using LISREL 8, and as predicted, children's identification with their mothers and fathers moderated the relationship between their perceptions of their mothers' and fathers' job insecurity and their own cognitive difficulties.

  17. Leaf and plant age affects photosynthetic performance and photoprotective capacity.

    PubMed

    Bielczynski, Ludwik Wiktor; Łącki, Mateusz Krzysztof; Hoefnagels, Iris; Gambin, Anna; Croce, Roberta

    2017-10-10

    In this work, we studied the changes in high light tolerance and photosynthetic activity in leaves of the Arabidopsis thaliana rosette throughout the vegetative stage of growth. We implemented an image analysis workflow to analyze the capacity of both the whole plant and individual leaves to cope with excess excitation energy by following the changes in the absorbed light energy partitioning. The data show that leaf and plant age are both important factors influencing the fate of excitation energy. During the dark-to-light transition, the age of the plant affects mostly steady state levels of photochemical and non-photochemical quenching (NPQ), leading to an increased photosynthetic performance of its leaves. The age of the leaf affects the induction kinetics of NPQ. These observations were confirmed using model selection procedures. We further investigate how different leaves on a rosette acclimate to high light and show that younger leaves are less prone to photoinhibition than older leaves. Our results stress that both plant and leaf age should be taken into consideration during the quantification of photosynthetic and photoprotective traits to produce repeatable and reliable results. {copyright, serif} 2017 American Society of Plant Biologists. All rights reserved.

  18. 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.

  19. 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

  20. Problematizing the concept of the "borderline" group in performance assessments.

    PubMed

    Homer, Matt; Pell, Godfrey; Fuller, Richard

    2017-05-01

    Many standard setting procedures focus on the performance of the "borderline" group, defined through expert judgments by assessors. In performance assessments such as Objective Structured Clinical Examinations (OSCEs), these judgments usually apply at the station level. Using largely descriptive approaches, we analyze the assessment profile of OSCE candidates at the end of a five year undergraduate medical degree program to investigate the consistency of the borderline group across stations. We look specifically at those candidates who are borderline in individual stations, and in the overall assessment. While the borderline group can be clearly defined at the individual station level, our key finding is that the membership of this group varies considerably across stations. These findings pose challenges for some standard setting methods, particularly the borderline group and objective borderline methods. They also suggest that institutions should ensure appropriate conjunctive rules to limit compensation in performance between stations to maximize "diagnostic accuracy". In addition, this work highlights a key benefit of sequential testing formats in OSCEs. In comparison with a traditional, single-test format, sequential models allow assessment of "borderline" candidates across a wider range of content areas with concomitant improvements in pass/fail decision-making.

  1. Piano Performance: Group Classes for the Lifelong Learner

    ERIC Educational Resources Information Center

    Haddon, Elizabeth

    2017-01-01

    This qualitative research presents data relating to eight amateur pianists who completed a 10-week Piano Performance course for lifelong learners at the University of York, UK. This article discusses the development of learning through the impact of group participation, challenges faced by learners and pedagogical strategies used by the leader to…

  2. Effective Use of Collaborative Information Technology to Enhance Group Performance

    DTIC Science & Technology

    2004-09-01

    asynchronous communication and information sharing among inter-connected entities. Despite the widely publicized potential of these collaborative technologies ...COLLABORATIVE INFORMATION TECHNOLOGY TO ENHANCE GROUP PERFORMANCE by Patrick Gallaher and Julie O’Rourke September 2004 Thesis Advisor...knowledge dominance to the DoD. Since superior information management and the use of collaborative IT technologies is fundamental to building

  3. Using Group Performances to Demonstrate Concepts in Large Biology Classes

    ERIC Educational Resources Information Center

    Wellnitz, Todd

    2006-01-01

    While a voluminous lecture hall can present obstacles to effective teaching and learning, large classrooms containing more than 100 students also present teaching opportunities. The lecture hall offers an excellent arena for demonstrating concepts that lend themselves to demonstrations and something this author refers to as "group performances."…

  4. Using Group Performances to Demonstrate Concepts in Large Biology Classes

    ERIC Educational Resources Information Center

    Wellnitz, Todd

    2006-01-01

    While a voluminous lecture hall can present obstacles to effective teaching and learning, large classrooms containing more than 100 students also present teaching opportunities. The lecture hall offers an excellent arena for demonstrating concepts that lend themselves to demonstrations and something this author refers to as "group performances."…

  5. High variability impairs motor learning regardless of whether it affects task performance.

    PubMed

    Cardis, Marco; Casadio, Maura; Ranganathan, Rajiv

    2017-09-27

    Motor variability plays an important role in motor learning, although the exact mechanisms of how variability affects learning is not well understood. Recent evidence suggests that motor variability may have different effects on learning in redundant tasks, depending on whether it is present in the task space (where it affects task performance), or in the null space (where it has no effect on task performance). Here we examined the effect of directly introducing null and task space variability using a manipulandum during the learning of a motor task. Participants learned a bimanual shuffleboard task for 2 days, where their goal was to slide a virtual puck as close as possible towards a target. Critically, the distance traveled by the puck was determined by the sum of the left and right hand velocities, which meant that there was redundancy in the task. Participants were divided into five groups - based on both the dimension in which the variability was introduced and the amount of variability that was introduced during training. Results showed that although all groups were able to reduce error with practice, learning was affected more by the amount of variability introduced rather than the dimension in which variability was introduced. Specifically, groups with higher movement variability during practice showed larger errors at the end of practice compared to groups that had low variability during learning. These results suggest that although introducing variability can increase exploration of new solutions, this may adversely affect the ability to retain the learned solution. Copyright © 2017, Journal of Neurophysiology.

  6. Cost and performance of Group 2 boiler NOx controls

    SciTech Connect

    Khan, S.; Maibodi, M.; Srivastava, R.

    1997-12-31

    This paper presents the results of a study conducted to assist EPA in developing the Phase II NO{sub x} rule under Title IV of the Clean Air Act Amendment of 1990 (the Act). The specific purpose of this study was to assess the performance and capital and total levelized costs of NO{sub x} controls pertinent to Group 2 boilers. Group 2 boilers are all coal-fired boilers that are not dry-bottom wall-fired and tangentially fired and include cell burner-fired, cyclone-fired, wet-bottom, vertically fired, stoker-fired, and fluidized-bed boilers.

  7. Guidelines for Performing Dermatologic Ultrasound Examinations by the DERMUS Group.

    PubMed

    Wortsman, Ximena; Alfageme, Fernando; Roustan, Gaston; Arias-Santiago, Salvador; Martorell, Antonio; Catalano, Orlando; Scotto di Santolo, Maria; Zarchi, Kian; Bouer, Marcio; Gonzalez, Claudia; Bard, Robert; Mandava, Anitha; Gaitini, Diana

    2016-03-01

    To support standardization for performing dermatologic ultrasound examinations. An international working group, called DERMUS (Dermatologic Ultrasound), was formed, composed of physicians who have been working on a regular basis and publishing in peer-reviewed articles on dermatologic ultrasound. A questionnaire on 5 critical issues about performance of the examinations was prepared and distributed by e-mail. The areas of discussion included technical aspects, main areas of application, minimum number of examinations per year required for assessing competence, qualifications of the personnel in charge of the examination, and organization of courses. Final recommendations were approved on the basis of the agreement of more than 50% of the members. The minimum frequency recommended for performing dermatologic examinations was 15 MHz. Routine use of color Doppler ultrasound and the performance of spectral curve analysis for assessing the main vascularity of lesions were suggested. Three-dimensional reconstructions were considered optional. The main dermatologic applications were benign tumors, skin cancer, vascular anomalies, cosmetic field, nail disorders, and inflammatory diseases. The minimum number of examinations per year suggested by the group for assessing competence was 300. A physician and not a sonographer was recommended to be the person in charge of performing the examination. On course organization, a minimum of 2 levels of complexity (basic and advanced) was suggested. There is a need to standardize the performance and quality of dermatologic ultrasound examinations. The present guidelines written by an international group of specialists in the field may support this objective. © 2016 by the American Institute of Ultrasound in Medicine.

  8. High Oxygen Concentrations Adversely Affect the Performance of Pulmonary Surfactant.

    PubMed

    Smallwood, Craig D; Boloori-Zadeh, Parnian; Silva, Maricris R; Gouldstone, Andrew

    2017-08-01

    Although effective in the neonatal population, exogenous pulmonary surfactant has not demonstrated a benefit in pediatric and adult subjects with hypoxic lung injury despite a sound physiologic rationale. Importantly, neonatal surfactant replacement therapy is administered in conjunction with low fractional FIO2 while pediatric/adult therapy is administered with high FIO2 . We suspected a connection between FIO2 and surfactant performance. Therefore, we sought to assess a possible mechanism by which the activity of pulmonary surfactant is adversely affected by direct oxygen exposure in in vitro experiments. The mechanical performance of pulmonary surfactant was evaluated using 2 methods. First, Langmuir-Wilhelmy balance was utilized to study the reduction in surface area (δA) of surfactant to achieve a low bound value of surface tension after repeated compression and expansion cycles. Second, dynamic light scattering was utilized to measure the size of pulmonary surfactant particles in aqueous suspension. For both experiments, comparisons were made between surfactant exposed to 21% and 100% oxygen. The δA of surfactant was 21.1 ± 2.0% and 35.8 ± 2.0% during exposure to 21% and 100% oxygen, respectively (P = .02). Furthermore, dynamic light-scattering experiments revealed a micelle diameter of 336.0 ± 12.5 μm and 280.2 ± 11.0 μm in 21% and 100% oxygen, respectively (P < .001), corresponding to a ∼16% decrease in micelle diameter following exposure to 100% oxygen. The characteristics of pulmonary surfactant were adversely affected by short-term exposure to oxygen. Specifically, surface tension studies revealed that short-term exposure of surfactant film to high concentrations of oxygen expedited the frangibility of pulmonary surfactant, as shown with the δA. This suggests that reductions in pulmonary compliance and associated adverse effects could begin to take effect in a very short period of time. If these findings can be demonstrated in vivo, a role for

  9. One (rating) from many (observations): Factors affecting the individual assessment of voice behavior in groups.

    PubMed

    Podsakoff, Nathan P; Maynes, Timothy D; Whiting, Steven W; Podsakoff, Philip M

    2015-07-01

    This article reports an investigation into how individuals form perceptions of overall voice behavior in group contexts. More specifically, the authors examine the effect of the proportion of group members exhibiting voice behavior in the group, the frequency of voice events in the group, and the measurement item referent (group vs. individual) on an individual's ratings of group voice behavior. In addition, the authors examine the effect that measurement item referent has on the magnitude of the relationship observed between an individual's ratings of group voice behavior and perceptions of group performance. Consistent with hypotheses, the results from 1 field study (N = 220) and 1 laboratory experiment (N = 366) indicate that: (a) When group referents were used, raters relied on the frequency of voice events (and not the proportion of group members exhibiting voice) to inform their ratings of voice behavior, whereas the opposite was true when individual-referent items were used, and (b) the magnitude of the relationship between observers' ratings of group voice behavior and their perceptions of group performance was higher when raters used group-referent, as opposed to an individual-referent, items. The authors discuss the implications of their findings for scholars interested in studying behavioral phenomena occurring in teams, groups, and work units in organizational behavior research.

  10. Factors affecting student performance in an undergraduate genetics course.

    PubMed

    Bormann, J Minick; Moser, D W; Bates, K E

    2013-05-01

    The objective of this study was to determine some of the factors that affect student success in a genetics course. Genetics for the Kansas State University College of Agriculture is taught in the Department of Animal Sciences and Industry and covers Mendelian inheritance, molecular genetics, and quantitative/population genetics. Data collected from 1,516 students over 7 yr included year and semester of the course; age; gender; state of residence; population of hometown; Kansas City metro resident or not; instructor of course; American College Testing Program (ACT) scores; number of transfer credits; major; college; preveterinary student or not; freshman, sophomore, junior, and senior grade point average (GPA); semester credits when taking genetics; class standing when enrolled in genetics; cumulative GPA before and after taking genetics; semester GPA in semester taking genetics, number of semesters between the biology prerequisite and genetics; grade in biology; location of biology course; and final percentage in genetics. Final percentage in genetics did not differ due to instructor, gender, state of residence, major, or college (P > 0.16). Transfer students tended to perform better than nontransfer students (P = 0.09), and students from the Kansas City metro outscored students from other areas (P = 0.03). Preveterinary option students scored higher in genetics than non-preveterinary students (P < 0.01). Seniors scored higher than juniors and sophomores, who scored higher than freshmen (P < 0.02). We observed a tendency for students with higher grades in biology to perform better in genetics (P = 0.06). Students who took biology at Kansas State University performed better in genetics than students who transferred the credit (P < 0.01). There was a negative regression of hometown population on score in genetics (P < 0.01), and positive regressions of ACT score, all measures of GPA, course load, and cumulative credits on final percentage in the course (P < 0.02). To

  11. PTS performance by flight- and control-group macaques

    NASA Technical Reports Server (NTRS)

    Washburn, D. A.; Rumbaugh, D. M.; Richardson, W. K.; Gulledge, J. P.; Shlyk, G. G.; Vasilieva, O. N.

    2000-01-01

    A total of 25 young monkeys (Macaca mulatta) were trained with the Psychomotor Test System, a package of software tasks and computer hardware developed for spaceflight research with nonhuman primates. Two flight monkeys and two control monkeys were selected from this pool and performed a psychomotor task before and after the Bion 11 flight or a ground-control period. Monkeys from both groups showed significant disruption in performance after the 14-day flight or simulation (plus one anesthetized day of biopsies and other tests), and this disruption appeared to be magnified for the flight animal.

  12. PTS performance by flight- and control-group macaques

    NASA Technical Reports Server (NTRS)

    Washburn, D. A.; Rumbaugh, D. M.; Richardson, W. K.; Gulledge, J. P.; Shlyk, G. G.; Vasilieva, O. N.

    2000-01-01

    A total of 25 young monkeys (Macaca mulatta) were trained with the Psychomotor Test System, a package of software tasks and computer hardware developed for spaceflight research with nonhuman primates. Two flight monkeys and two control monkeys were selected from this pool and performed a psychomotor task before and after the Bion 11 flight or a ground-control period. Monkeys from both groups showed significant disruption in performance after the 14-day flight or simulation (plus one anesthetized day of biopsies and other tests), and this disruption appeared to be magnified for the flight animal.

  13. Relationships among affect, work, and outcome in group therapy for patients with complicated grief.

    PubMed

    Piper, William E; Ogrodniczuk, John S; Joyce, Anthony S; McCallum, Mary; Rosie, John S

    2002-01-01

    This study examined the relationships among patient affect (experienced and expressed), work, and outcome in two forms of time-limited, short-term group therapy for complicated grief. Work was defined as the degree to which the patient pursued the primary objectives of the two forms of therapy. Substantial evidence of direct relationships between the experience and expression of positive affect and favorable outcome was found. A direct relationship between work and favorable outcome was also found. Additive and interaction effects indicated that the combination of these two types of predictor variables (positive affect, work) had a stronger relationship to favorable outcome than either variable alone. Some evidence was found for an inverse relationship between the experience and expression of negative affect and favorable outcome. The findings were consistent with a social-functional theory of the impact of affect on others during bereavement. Clinical implications of the findings are considered.

  14. Communication as group process media of aircrew performance

    NASA Technical Reports Server (NTRS)

    Kanki, B. G.; Foushee, H. C.

    1989-01-01

    This study of group process was motivated by a high-fidelity flight simulator project in which aircrew performance was found to be better when the crew had recently flown together. Considering recent operating experience as a group-level input factor, aspects of the communication process between crewmembers (Captain and First Officer), were explored as a possible mediator to performance. Communication patterns were defined by a speech act typology adapted for the flightdeck setting and distinguished crews that had previously flown together (FT) from those that had not flown together (NFT). A more open communication channel with respect to information exchange and validation and greater First Officer participation in task-related topics was shown by FT crews while NFT crews engaged in more non-task discourse, a speech mode less structured by roles and probably serving a more interpersonal function. Relationships between the speech categories themselves, representing linguistic, and role-related interdependencies provide guidelines for interpreting the primary findings.

  15. Communication as group process media of aircrew performance

    NASA Technical Reports Server (NTRS)

    Kanki, B. G.; Foushee, H. C.

    1989-01-01

    This study of group process was motivated by a high-fidelity flight simulator project in which aircrew performance was found to be better when the crew had recently flown together. Considering recent operating experience as a group-level input factor, aspects of the communication process between crewmembers (Captain and First Officer), were explored as a possible mediator to performance. Communication patterns were defined by a speech act typology adapted for the flightdeck setting and distinguished crews that had previously flown together (FT) from those that had not flown together (NFT). A more open communication channel with respect to information exchange and validation and greater First Officer participation in task-related topics was shown by FT crews while NFT crews engaged in more non-task discourse, a speech mode less structured by roles and probably serving a more interpersonal function. Relationships between the speech categories themselves, representing linguistic, and role-related interdependencies provide guidelines for interpreting the primary findings.

  16. Alpha Suppression Following Performance Errors is Correlated With Depression, Affect, and Coping Behaviors

    PubMed Central

    Compton, Rebecca J.

    2015-01-01

    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

  17. Malaysian Students' Scientific Argumentation: Do groups perform better than individuals?

    NASA Astrophysics Data System (ADS)

    Heng, Lee Ling; Surif, Johari; Hau Seng, Cher

    2015-02-01

    The practices of argumentation have recently been upheld as an important need to develop students' understanding of scientific concepts. However, the present education system in Malaysia is still largely examination-based and teacher-oriented. Thus, this study aims to examine the mastery level of scientific argumentation and its scheme among Malaysian secondary-level science students. A total of 120 students were randomly assigned to answer a Scientific Argumentation Test (SAT), either individually or in a group. Based on the answers, two groups of students, one who have answered with valid scientific concepts and another who have answered with invalid concepts, were identified and interviewed. Quantitative analysis was performed on the SAT results to determine students' mastery of scientific argumentation, and their argumentation schemes were assessed using content analysis performed on the interview transcripts. The results showed that students were weak in the construction of scientific arguments with valid concepts. Moreover, most of the constructed arguments consisted of misconceptions. The results also showed that students who were involved in group argumentation tended to have a more complex argumentation scheme, compared to individual students. As a group, students were able to argue with more scientific elements and showed their understanding of macro and submicro concepts. Hence, science teachers need to emphasize on the construction of scientific argumentation in their teaching, especially at the macro, submicro, and symbolic levels of representations, to ensure students' understanding of the concepts. This will therefore enhance their mastery of scientific argumentation and improve their content knowledge.

  18. What makes a 'good group'? Exploring the characteristics and performance of undergraduate student groups.

    PubMed

    Channon, S B; Davis, R C; Goode, N T; May, S A

    2017-03-01

    Group work forms the foundation for much of student learning within higher education, and has many educational, social and professional benefits. This study aimed to explore the determinants of success or failure for undergraduate student teams and to define a 'good group' through considering three aspects of group success: the task, the individuals, and the team. We employed a mixed methodology, combining demographic data with qualitative observations and task and peer evaluation scores. We determined associations between group dynamic and behaviour, demographic composition, member personalities and attitudes towards one another, and task success. We also employed a cluster analysis to create a model outlining the attributes of a good small group learning team in veterinary education. This model highlights that student groups differ in measures of their effectiveness as teams, independent of their task performance. On the basis of this, we suggest that groups who achieve high marks in tasks cannot be assumed to have acquired team working skills, and therefore if these are important as a learning outcome, they must be assessed directly alongside the task output.

  19. Aggression in pigtailed macaque (Macaca nemestrina) breeding groups affects pregnancy outcome

    PubMed Central

    Ha, James; Alloway, Hayley; Sussman, Adrienne

    2011-01-01

    Past research has shown that aggressive behaviors can affect female reproductive outcome in non-human primate captive breeding programs. In this study, aggressive behaviors were recorded in a colony of pigtailed macaque monkeys (Macaca nemestrina) and related to pregnancy outcome. For twenty-two weeks, behavioral data were collected from nine breeding groups, consisting of zero to one male (some males were removed after a cycle of conceptions for husbandry reasons) and four to eight females. Observations included all occurrences of eleven aggressive behaviors during 15-minute observation sessions, one to three times a week. Mean weekly aggression levels during the study period were determined for each group, as well as for each pregnancy. Aggression data were summarized with Principal Components Analyses (PCA). Results indicate that pigtailed macaque aggression falls into five distinctive categories: warn, engage, threaten, pursue, and attack. Breeding groups differed in their levels of aggression, even after controlling for group size, presence of a sire, and group stability. Levels of the five aggression categories were found to affect the probability that a pregnancy ended in either a natural birth of a live infant, a clinical intervention producing a live infant, or a nonviable outcome. The predictive value of aggression was significant when clinical interventions were included as possible reproductive outcomes, Behavioral observation of captive groups could identify “risk” conditions affecting pregnancy outcome and the requirement for clinical intervention. PMID:21898511

  20. Fewer but better: Proportionate size of the group affects evaluation of transgressive leaders.

    PubMed

    Travaglino, Giovanni A; Abrams, Dominic; Randsley de Moura, Georgina; Yetkili, Orkun

    2016-06-01

    A group may be badly affected if its leader transgresses important rules. Nonetheless, an emerging body of evidence suggests that in intergroup contexts, group members apply a double standard when judging ingroup leaders - They respond less punitively to transgressions by their leader than by non-leaders. In this article, two experiments investigated how proportionate ingroup size affects reactions to transgressive ingroup leaders. We demonstrate that ingroup leaders from larger, but not smaller, groups benefit from the double standard. The experiments testing the effects of two different types of transgressions (nepotistic favouritism and corruption, respectively) show that transgressive leaders from larger groups are evaluated more positively than both comparable non-leaders and leaders from smaller groups. In contrast, transgressive leaders from smaller groups are evaluated similarly to comparable transgressive non-leaders. Experiment 2 investigated a potential explanation for this phenomenon. Faced with a transgressive leader, members of a smaller group report greater embarrassment than do members of larger groups in relation to the leaders' actions. Implications of these findings and directions for future research are discussed. © 2015 The British Psychological Society.

  1. Foraging in groups affects giving-up densities: solo foragers quit sooner.

    PubMed

    Carthey, Alexandra J R; Banks, Peter B

    2015-07-01

    The giving-up density framework is an elegant and widely adopted mathematical approach to measuring animals' foraging decisions at non-replenishing artificial resource patches. Under this framework, an animal should "give up" when the benefits of foraging are outweighed by the costs (e.g., predation risk, energetic, and/or missed opportunity costs). However, animals of many species may forage in groups, and group size is expected to alter perceived predation risk and hence influence quitting decisions. Yet, most giving-up density studies assume either that individuals forage alone or that giving-up densities are not affected by group foraging. For animals that forage both alone and in groups, differences in giving-up densities due to group foraging rather than experimental variables may substantially alter interpretation. However, no research to date has directly investigated how group foraging affects the giving-up density. We used remote-sensing cameras to identify instances of group foraging in two species of Rattus across three giving-up density experiments to determine whether group foraging influences giving-up densities. Both Rattus species have been observed to vary between foraging alone and in groups. In all three experiments, solo foragers left higher giving-up densities on average than did group foragers. This result has important implications for studies using giving-up densities to investigate perceived risk, the energetic costs of searching, handling time, digestion, and missed opportunity costs, particularly if groups of animals are more likely to experience certain experimental treatments. It is critically important that future giving-up density studies consider the effects of group foraging.

  2. How Does Tele-Mental Health Affect Group Therapy Process? Secondary Analysis of a Noninferiority Trial

    ERIC Educational Resources Information Center

    Greene, Carolyn J.; Morland, Leslie A.; Macdonald, Alexandra; Frueh, B. Christopher; Grubbs, Kathleen M.; Rosen, Craig S.

    2010-01-01

    Objective: Video teleconferencing (VTC) is used for mental health treatment delivery to geographically remote, underserved populations. However, few studies have examined how VTC affects individual or group psychotherapy processes. This study compares process variables such as therapeutic alliance and attrition among participants receiving anger…

  3. Testing Measurement Invariance of the Students' Affective Characteristics Model across Gender Sub-Groups

    ERIC Educational Resources Information Center

    Demir, Ergül

    2017-01-01

    In this study, the aim was to construct a significant structural measurement model comparing students' affective characteristics with their mathematic achievement. According to this model, the aim was to test the measurement invariances between gender sub-groups hierarchically. This study was conducted as basic and descriptive research. Secondary…

  4. How Does Tele-Mental Health Affect Group Therapy Process? Secondary Analysis of a Noninferiority Trial

    ERIC Educational Resources Information Center

    Greene, Carolyn J.; Morland, Leslie A.; Macdonald, Alexandra; Frueh, B. Christopher; Grubbs, Kathleen M.; Rosen, Craig S.

    2010-01-01

    Objective: Video teleconferencing (VTC) is used for mental health treatment delivery to geographically remote, underserved populations. However, few studies have examined how VTC affects individual or group psychotherapy processes. This study compares process variables such as therapeutic alliance and attrition among participants receiving anger…

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

    Treesearch

    Ronald S., Jr. Zalesny

    2006-01-01

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

  6. [Research on the performance comparing and building of affective computing database based on physiological parameters].

    PubMed

    Li, Xin; Du, Xiaojuan; Zhang, Yunpeng; Ying, Lijuan; Li, Changwuz

    2014-08-01

    The validity and reasonableness of emotional data are the key issues in the cognitive affective computing research. Effects of the emotion recognition are decided by the quality of selected data directly. Therefore, it is an important part of affective computing research to build affective computing database with good performance, so that it is the hot spot of research in this field. In this paper, the performance of two classical cognitive affective computing databases, the Massachusetts Institute of Technology (MIT) cognitive affective computing database and Germany Augsburg University emotion recognition database were compared, their data structure and data types were compared respectively, and emotional recognition effect based on the data were studied comparatively. The results indicated that the analysis based on the physical parameters could get the effective emotional recognition, and would be a feasible method of pressure emotional evaluation. Because of the lack of stress emotional evaluation data based on the physiological parameters domestically, there is not a public stress emotional database. We hereby built a dataset for the stress evaluation towards the high stress group in colleges, candidates of postgraduates of Ph. D and master as the subjects. We then acquired their physiological parameters, and performed the pressure analysis based on this database. The results indicated that this dataset had a certain reference value for the stress evaluation, and we hope this research can provide a reference and support for emotion evaluation and analysis.

  7. Negative affect reduces performance in implicit sequence learning.

    PubMed

    Shang, Junchen; Fu, Qiufang; Dienes, Zoltan; Shao, Can; Fu, Xiaolan

    2013-01-01

    It is well documented that positive rather than negative moods encourage integrative processing of conscious information. However, the extent to which implicit or unconscious learning can be influenced by affective states remains unclear. A Serial Reaction Time (SRT) task with sequence structures requiring integration over past trials was adopted to examine the effect of affective states on implicit learning. Music was used to induce and maintain positive and negative affective states. The present study showed that participants in negative rather than positive states learned less of the regularity. Moreover, the knowledge was shown by a Bayesian analysis to be largely unconscious as participants were poor at recognizing the regularity. The results demonstrated that negative rather than positive affect inhibited implicit learning of complex structures. Our findings help to understand the effects of affective states on unconscious or implicit processing.

  8. Affiliation affects generosity in young children: The roles of minimal group membership and shared interests.

    PubMed

    Sparks, Erin; Schinkel, Meghan G; Moore, Chris

    2017-03-16

    Young children's willingness to share with others is selective, and is affected by their level of affiliation with the recipients of their generosity. We explored affiliation's impact on sharing behavior with two experiments comparing the effects of two distinct affiliative cues-minimal group membership and shared interests. Children (4- to 6-year-olds) completed a resource allocation task, making forced-choice decisions as to how to distribute stickers between themselves and others. In Experiment 1, the sharing partners were minimal in- and out-group members; in Experiment 2, they differed in their opinion of the participants' interests. Both experiments' manipulations affected feelings of affiliation, as indicated by children's stated friendship preferences and perceptions of similarity. More notably, both minimal group membership and interests affected sharing behavior. Children made fewer generous allocations toward out-group members than toward in-group members. Similarly, children made fewer generous allocations when recipients disliked their interests than when recipients shared those interests or when their opinions were unknown. Across experiments, the recipient manipulations' effects on generosity were similar in their pattern and magnitude despite fundamental differences between the two affiliative cues. These findings highlight the broad impact of affiliation on young children's sharing behavior.

  9. Do I Know You? How Individual Recognition Affects Group Formation and Structure

    PubMed Central

    2017-01-01

    Groups in nature can be formed by interactions between individuals, or by external pressures like predation. It is reasonable to assume that groups formed by internal and external conditions have different dynamics and structures. We propose a computational model to investigate the effects of individual recognition on the formation and structure of animal groups. Our model is composed of agents that can recognize each other and remember previous interactions, without any external pressures, in order to isolate the effects of individual recognition. We show that individual recognition affects the number and size of groups, and the modularity of the social networks. This model can be used as a null model to investigate the effects of external factors on group formation and persistence. PMID:28125708

  10. Communication as group process mediator of aircrew performance

    NASA Technical Reports Server (NTRS)

    Kanki, Barbara G.; Foushee, H. Clayton

    1989-01-01

    Considering recent operating experience as a group-level input factor, aspects of the communication process between crewmembers (captain and first officer) were explored as a possible mediator to performance. Communication patterns were defined by a speech-act typology adapted for the flight-deck setting and distinguished crews that had previously flown together (FT) from those that had not flown together (NFT). A more open communication channel and greater first officer participation in task-related topics was shown by FT crews, while NFT crews engaged in more nontask discourse.

  11. Communication as group process mediator of aircrew performance

    NASA Technical Reports Server (NTRS)

    Kanki, Barbara G.; Foushee, H. Clayton

    1989-01-01

    Considering recent operating experience as a group-level input factor, aspects of the communication process between crewmembers (captain and first officer) were explored as a possible mediator to performance. Communication patterns were defined by a speech-act typology adapted for the flight-deck setting and distinguished crews that had previously flown together (FT) from those that had not flown together (NFT). A more open communication channel and greater first officer participation in task-related topics was shown by FT crews, while NFT crews engaged in more nontask discourse.

  12. Item Context Factors Affecting Students' Performance on Mathematics Items

    ERIC Educational Resources Information Center

    Salgado, Felipe Almuna; Stacey, Kaye

    2014-01-01

    This paper reports how the context in which a mathematics item is embedded impacts on students' performance. The performance of Year 10 students on four PISA items was compared with performance on variants with more familiar contexts. Performance was not better when they solved items with more familiar contexts but there was some evidence that…

  13. Prepartum nutritional strategy affects reproductive performance in dairy cows.

    PubMed

    Cardoso, F C; LeBlanc, S J; Murphy, M R; Drackley, J K

    2013-09-01

    Negative energy balance during early postpartum is associated with reduced reproductive performance in dairy cows. A pooled statistical analysis of 7 studies completed in our group from 1993 to 2010 was conducted to investigate the association between prepartum energy feeding regimen and reproductive performance. The interval from calving to pregnancy (days to pregnancy, DTP) was the dependent variable to assess reproductive performance. Individual data for 408 cows (354 multiparous and 54 primiparous) were included in the analysis. The net energy for lactation (NEL) intake was determined from each cow's average dry matter intake and calculated dietary NEL density. Treatments applied prepartum were classified as either controlled-energy (CE; limited NEL intake to ≤100% of requirement) or high-energy (HE; cows were allowed to consume >100%) diets fed during the far-off (FO) or close-up (CU) dry periods. Cow was the experimental unit. The Cox proportional hazard model revealed that days to pregnancy was shorter for CE (median=157 d) than HE (median=167 d) diets during the CU period [hazard ratio (HR)=0.70]. Cows fed HE diets during the last 4 wk prepartum lost more body condition score in the first 6 wk postpartum than those fed CE diets (-0.43 and -0.30, respectively). Cows fed CE diets during the FO period had lower nonesterified fatty acids concentrations in wk 1, 2, and 3 of lactation than cows fed HE diets. Higher nonesterified fatty acids concentration in wk 1 postpartum was associated with a greater probability of disease (n=251; odds ratio=1.18). Cows on the CE regimen during the FO period had greater plasma glucose concentrations during wk 1 and 3 after calving than cows fed the HE regimen. Higher plasma glucose (HG) concentration compared with lower glucose (LG) in wk 3 (HG: n=154; LG: n=206) and wk 4 (HG: n=71; LG: n=254) after calving was associated with shorter days to pregnancy (wk 3: median=151 and 171 d for HG and LG, respectively, and HR=1.3; wk 4

  14. [Treatment utilisation of a psychoeducational group for relatives of patients with affective disorders].

    PubMed

    Kronmüller, K-T; Kratz, B; Karr, M; Schenkenbach, C; Mundt, C; Backenstrass, M

    2006-03-01

    The relevance of family interactions in the course of affective disorders has been well described. In contrast to the situation regarding schizophrenic disorders, there are few systematic concepts for involvement of the relatives of patients with affective disorders in treatment. The goal of this study was the development and evaluation of a standardised psychoeducational treatment programme. We determined the number and characteristics of relatives accepting the offer of such a group. Relatives of almost half of 55 patients with major depression and a bipolar disorder participated in the group. Relatives of male patients were more likely to take part than relatives of female patients. Relatives of patients with a bipolar disorder were more likely to take part than relatives of patients with unipolar depression. The patients whose relatives attended the group showed a more favourable understanding of the illness and more knowledge about affective disorders, but on the other hand, felt themselves to be more strongly criticised by their relatives and had less social support than the other patients. These results emphasise the importance of differential family-focused treatment modalities in affective disorders.

  15. Dietary electrolyte balance affects growth performance, amylase activity and metabolic response in the meagre (Argyrosomus regius).

    PubMed

    Magnoni, Leonardo J; Salas-Leiton, Emilio; Peixoto, Maria-João; Pereira, Luis; Silva-Brito, Francisca; Fontinha, Filipa; Gonçalves, José F M; Wilson, Jonathan M; Schrama, Johan W; Ozório, Rodrigo O A

    2017-09-01

    Dietary ion content is known to alter the acid-base balance in freshwater fish. The current study investigated the metabolic impact of acid-base disturbances produced by differences in dietary electrolyte balance (DEB) in the meagre (Argyrosomus regius), an euryhaline species. Changes in fish performance, gastric chyme characteristics, pH and ion concentrations in the bloodstream, digestive enzyme activities and metabolic rates were analyzed in meagre fed ad libitum two experimental diets (DEB 200 or DEB 700mEq/kg) differing in the Na2CO3 content for 69days. Fish fed the DEB 200 diet had 60-66% better growth performance than the DEB 700 group. Meagre consuming the DEB 200 diet were 90-96% more efficient than fish fed the DEB 700 diet at allocating energy from feed into somatic growth. The pH values in blood were significantly lower in the DEB 700 group 2h after feeding when compared to DEB 200, indicating that acid-base balance in meagre was affected by electrolyte balance in diet. Osmolality, and Na(+) and K(+) concentrations in plasma did not vary with the dietary treatment. Gastric chyme in the DEB 700 group had higher pH values, dry matter, protein and energy contents, but lower lipid content than in the DEB 200 group. Twenty-four hours after feeding, amylase activity was higher in the gastrointestinal tract of DEB 700 group when compared to the DEB 200 group. DEB 700 group had lower routine metabolic (RMR) and standard metabolic (SMR) rates, indicating a decrease in maintenance energy expenditure 48h after feeding the alkaline diet. The current study demonstrates that feeding meagre with an alkaline diet not only causes acid-base imbalance, but also negatively affects digestion and possibly nutrient assimilation, resulting in decreased growth performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. 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

  17. Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

    PubMed

    Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

    2017-08-01

    Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p < 0.001; D3: 19.7 vs. 27.1 vs. 21.2%; p = 0.029; Group 1. vs. Group 2. vs. Group 3). Cell number on Day 3 differed between Groups 1 and 2 (6.8 ± 2.2; 7.3 ± 2.1; p = 0.004) and Groups 2 and 3 (7.3 ± 2.1 vs. 7.0 ± 2.0; p = 0.014). Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

  18. Predicting nitrogen loading with land-cover composition: how can watershed size affect model performance?

    PubMed

    Zhang, Tao; Yang, Xiaojun

    2013-01-01

    Watershed-wide land-cover proportions can be used to predict the in-stream non-point source pollutant loadings through regression modeling. However, the model performance can vary greatly across different study sites and among various watersheds. Existing literature has shown that this type of regression modeling tends to perform better for large watersheds than for small ones, and that such a performance variation has been largely linked with different interwatershed landscape heterogeneity levels. The purpose of this study is to further examine the previously mentioned empirical observation based on a set of watersheds in the northern part of Georgia (USA) to explore the underlying causes of the variation in model performance. Through the combined use of the neutral landscape modeling approach and a spatially explicit nutrient loading model, we tested whether the regression model performance variation over the watershed groups ranging in size is due to the different watershed landscape heterogeneity levels. We adopted three neutral landscape modeling criteria that were tied with different similarity levels in watershed landscape properties and used the nutrient loading model to estimate the nitrogen loads for these neutral watersheds. Then we compared the regression model performance for the real and neutral landscape scenarios, respectively. We found that watershed size can affect the regression model performance both directly and indirectly. Along with the indirect effect through interwatershed heterogeneity, watershed size can directly affect the model performance over the watersheds varying in size. We also found that the regression model performance can be more significantly affected by other physiographic properties shaping nitrogen delivery effectiveness than the watershed land-cover heterogeneity. This study contrasts with many existing studies because it goes beyond hypothesis formulation based on empirical observations and into hypothesis testing to

  19. Group belongingness and procedural justice: social inclusion and exclusion by peers affects the psychology of voice.

    PubMed

    van Prooijen, Jan-Willem; van den Bos, Kees; Wilke, Henk A M

    2004-07-01

    The authors focus on the relation between group membership and procedural justice. They argue that whether people are socially included or excluded by their peers influences their reactions to unrelated experiences of procedural justice. Findings from 2 experiments corroborate the prediction that reactions to voice as opposed to no-voice procedures are affected more strongly when people are included in a group than when they are excluded from a group. These findings are extended with a 3rd experiment that shows that people who generally experience higher levels of inclusion in their lives respond more strongly to voice as opposed to no-voice procedures. It is concluded that people's reactions to procedural justice are moderated by people's level of inclusion in social groups.

  20. The effects of academic grouping on student performance in science

    NASA Astrophysics Data System (ADS)

    Scoggins, Sally Smykla

    The current action research study explored how student placement in heterogeneous or homogeneous classes in seventh-grade science affected students' eighth-grade Science State of Texas Assessment of Academic Readiness (STAAR) scores, and how ability grouping affected students' scores based on race and socioeconomic status. The population included all eighth-grade students in the target district who took the regular eighth-grade science STAAR over four academic school years. The researcher ran three statistical tests: a t-test for independent samples, a one-way between subjects analysis of variance (ANOVA) and a two-way between subjects ANOVA. The results showed no statistically significant difference between eighth-grade Pre-AP students from seventh-grade Pre-AP classes and eighth-grade Pre-AP students from heterogeneous seventh-grade classes and no statistically significant difference between Pre-AP students' scores based on socioeconomic status. There was no statistically significant interaction between socioeconomic status and the seventh-grade science classes. The scores between regular eighth-grade students who were in heterogeneous seventh-grade classes were statistically significantly higher than the scores of regular eighth-grade students who were in regular seventh-grade classes. The results also revealed that the scores of students who were White were statistically significantly higher than the scores of students who were Black and Hispanic. Black and Hispanic scores did not differ significantly. Further results indicated that the STAAR Level II and Level III scores were statistically significantly higher for the Pre-AP eighth-grade students who were in heterogeneous seventh-grade classes than the STAAR Level II and Level III scores of Pre-AP eighth-grade students who were in Pre-AP seventh-grade classes.

  1. Effort to reduce postural sway affects both cognitive and motor performances in individuals with Parkinson's disease.

    PubMed

    Sciadas, Ria; Dalton, Christopher; Nantel, Julie

    2016-06-01

    To assess the effects of voluntarily reducing postural sway on postural control and to determine the attention level needed to do so in healthy adults (n=16, 65.9±9.7) and persons with PD (n=25, 65.8±9.5 years). Tasks: quiet and still standing conditions with and without a category task. Cognitive performance, center of pressure (CoP) displacement variability (RMSCoP) and velocity (VCoP) were assessed in the anterior-posterior (AP) and medial-lateral (ML) directions. Controls showed larger RMSCoP (AP) and VCoP (AP and ML) during still versus quiet standing (p<0.01), while the PD group demonstrated no changes. In the PD group, RMSCoP and VCoP (ML) increased in still standing when performed with the cognitive task (p<0.05). In both groups, cognitive responses decreased in still standing (p<0.05). In PD, attempting to reduce postural sway did not affect postural control under single task conditions, however ML CoP variability and velocity did increase as a dual task. In older adults, increased displacement and velocity in both AP and ML directions was observed during single, but not dual task conditions. Therefore standing still might not be an adequate postural strategy as it increases the attentional demand and affects motor performance, putting persons with PD at greater risk for falls. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Decomposers (Lumbricidae, Collembola) affect plant performance in model grasslands of different diversity.

    PubMed

    Partsch, Stephan; Milcu, Alexandru; Scheu, Stefan

    2006-10-01

    Decomposer invertebrates influence soil structure and nutrient mineralization as well as the activity and composition of the microbial community in soil and therefore likely affect plant performance and plant competition. We established model grassland communities in a greenhouse to study the interrelationship between two different functional groups of decomposer invertebrates, Lumbricidae and Collembola, and their effect on plant performance and plant nitrogen uptake in a plant diversity gradient. Common plant species of Central European Arrhenatherion grasslands were transplanted into microcosms with numbers of plant species varying from one to eight and plant functional groups varying from one to four. Separate and combined treatments with earthworms and collembolans were set up. Microcosms contained 15N labeled litter to track N fluxes into plant shoots. Presence of decomposers strongly increased total plant and plant shoot biomass. Root biomass decreased in the presence of collembolans and even more in the presence of earthworms. However, it increased when both animal groups were present. Also, presence of decomposers increased total N concentration and 15N enrichment of grasses, legumes, and small herbs. Small herbs were at a maximum in the combined treatment with earthworms and collembolans. The impact of earthworms and collembolans on plant performance strongly varied with plant functional group identity and plant species diversity and was modified when both decomposers were present. Both decomposer groups generally increased aboveground plant productivity through effects on litter decomposition and nutrient mineralization leading to an increased plant nutrient acquisition. The non-uniform effects of earthworms and collembolans suggest that functional diversity of soil decomposer animals matters and that the interactions between soil animal functional groups affect the structure of plant communities.

  3. Predicting outcomes of group cognitive behavior therapy for patients with affective and neurotic disorders.

    PubMed

    Hooke, Geoffrey R; Page, Andrew C

    2002-10-01

    An attempt was made to predict outcomes following group Cognitive Behavior Therapy (CBT) for patients with affective and neurotic disorders. A group of 348 patients at a private psychiatric clinic, treated in a group CBT program, completed the Depression, Anxiety, and Stress Scale (DASS) before and after treatment. Prior to treatment, data from the Locus of Control of Behavior (LCB), a Global Assessment of Function (GAF), the Health of the Nation Outcome Scales (HoNOS), and the Rosenberg Self Esteem Scale (RSE) were also collected. Results indicated that posttreatment stress scores of all patients were predicted by pretreatment stress and self-esteem. Among patients with neurotic disorders, posttreatment anxiety was predicted by initial anxiety and self-esteem whereas among patients with affective disorders, posttreatment anxiety scores were predicted by initial anxiety and GAF. For patients with neurotic disorders, self-esteem did not predict variance in posttreatment depression in addition to that explained by pretreatment depression. In contrast, for patients with affective disorders, pretreatment depression and Locus of Control predicted posttreatment depression.

  4. Density and Age Affect Performance of Containerized Loblolly Pine Seedlings

    Treesearch

    James P. Barnett

    1980-01-01

    Loblolly pine seedlings were grown in 1 x 5 inch biodegradable plastic tubes for 10, 12, and 14 weeks at densities of 42, 84, 126, and 168 per square foot. Seedling density and age significantly affected seedling development at time of outplanting, and density became more important as greenhouse growing times increased. All morphological characteristics measured when...

  5. How Does Test Exemption Affect Schools' and Students' Academic Performance?

    ERIC Educational Resources Information Center

    Jennings, Jennifer L.; Beveridge, Andrew A.

    2009-01-01

    Analyzing data from a large urban district in Texas, this study examines how high-stakes test exemptions alter officially reported scores and asks whether test exemption has implications for the academic achievement of special education students. Test exemption inflated overall passing rates but especially affected the passing rates of African…

  6. 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…

  7. 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…

  8. Selected Factors Affecting the Performance Assessment of Elementary Teachers.

    ERIC Educational Resources Information Center

    Thomson, Scott

    1990-01-01

    This study determined whether nontraditional assessment factors (principal's gender, choice of subject matter for demonstrating competence, or years of teacher experience) would affect elementary teachers' scores when completing the Leon County (Florida) Teacher Assessment Process. Principal's gender and subject selected were significant…

  9. Executive dysfunction affects word list recall performance: Evidence from amyotrophic lateral sclerosis and other neurodegenerative diseases.

    PubMed

    Consonni, Monica; Rossi, Stefania; Cerami, Chiara; Marcone, Alessandra; Iannaccone, Sandro; Francesco Cappa, Stefano; Perani, Daniela

    2017-03-01

    The Rey Auditory Verbal Learning Test (RAVLT) is widely used in clinical practice to evaluate verbal episodic memory. While there is evidence that RAVLT performance can be influenced by executive dysfunction, the way executive disorders affect the serial position curve (SPC) has not been yet explored. To this aim, we analysed immediate and delayed recall performances of 13 non-demented amyotrophic lateral sclerosis (ALS) patients with a specific mild executive dysfunction (ALSci) and compared their performances to those of 48 healthy controls (HC) and 13 cognitively normal patients with ALS. Moreover, to control for the impact of a severe dysexecutive syndrome and a genuine episodic memory deficit on the SPC, we enrolled 15 patients with a diagnosis of behavioural variant of frontotemporal dementia (bvFTD) and 18 patients with probable Alzheimer's disease (AD). Results documented that, compared to cognitively normal subjects, ALSci patients had a selective mid-list impairment for immediate recall scores. The bvFTD group obtained low performances with a selectively increased forgetting rate for terminal items, whereas the AD group showed a disproportionately large memory loss on the primary and middle part of the SPC for immediate recall scores and were severely impaired in the delayed recall trial. These results suggested that subtle executive dysfunctions might influence the recall of mid-list items, possibly reflecting deficiency in control strategies at retrieval of word lists, whereas severer dysexecutive syndrome might also affect the recall of terminal items possibly due to attention deficit or retroactive interference.

  10. 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)

  11. 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…

  12. 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…

  13. 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…

  14. Bulk power system performance issues affecting utility peaking capacity additions

    SciTech Connect

    Garrity, T.F.

    1994-12-31

    This paper presents a discussion of transmission system constraints and problems that affect the siting and rating of peaking capacity additions. Techniques for addressing and modifying these concerns are presented. Particular attention is paid to techniques that have been successfully used by utilities to improve power transfer and system loadability, while avoiding the construction of additional transmission lines. Proven techniques for dealing with thermal, short-circuit level and stability issues are presented.

  15. Quarter of century since the Chornobyl accident: сancer risks in affected groups of population.

    PubMed

    Prysyazhnyuk, A Ye; Bazyka, D A; Romanenko, A Yu; Gudzenko, N A; Fuzik, M M; Trotsyuk, N K; Fedorenko, Z P; Gulak, L O; Slipenyuk, K M; Babkina, N G; Khukhrianska, O M; Goroh, Ye L; Berestyana, Zh M

    2014-09-01

    Objective. The goal of this study was to define levels and dynamic trends of cancer incidence at whole and some separate sites in groups of Ukrainian population affected by the Chornobyl accident during a long period of observation. Materials and methods. Those groups were Chornobyl accident recovery operation workers (CRW) of 1986-1987 years of participation, evacuees from Prypyat town and 30-km zone and residents of the most contaminated territories of Ukraine. Analysis was carried out with the standard methods of descriptive epidemiology: calculation of crude, age-specific and age-adjusted incidence rates with standard errors and confidence intervals. Results, discussion and conclusions. This study showed that all cancer incidences exceeded the national level only in CRW group. Decrease of cancer incidence rate in the recent years might be caused by shortened average life expectancy in Ukrainian population, especially in males. Statistically significant increase of leukemia incidence in CRW group was registered as well. Besides, in all three main affected groups there was revealed significant excess of thyroid cancer. Irradiation of thyroid due to radioactive iodine fallouts might be a main cause of this phenomenon. Increase of thyroid cancer incidence was registered not only in children, but also in adolescents and adults. Appearance of excess thyroid cancer cases as an effect of radiation exposure tends to increase during the time. Significant excess was also revealed for breast cancer in female CRW group. Because latency period for different nosological forms of radiation-induced malignant tumors varies widely, profound attention in further studies should be drawn not only to thyroid, breast cancers and leukemia, but also to malignancies with longer latent period: lung, stomach, colon, ovary, urinary bladder, kidney cancer and multiple myeloma. A. Ye. Prysyazhnyuk, D. A. Bazyka, A. Yu. Romanenko, N. A. Gudzenko, M. M. Fuzik, N. K. Trotsyuk, Z. P. Fedorenko, L

  16. Plant diversity and functional groups affect Si and Ca pools in aboveground biomass of grassland systems.

    PubMed

    Schaller, Jörg; Roscher, Christiane; Hillebrand, Helmut; Weigelt, Alexandra; Oelmann, Yvonne; Wilcke, Wolfgang; Ebeling, Anne; Weisser, Wolfgang W

    2016-09-01

    Plant diversity is an important driver of nitrogen and phosphorus stocks in aboveground plant biomass of grassland ecosystems, but plant diversity effects on other elements also important for plant growth are less understood. We tested whether plant species richness, functional group richness or the presence/absence of particular plant functional groups influences the Si and Ca concentrations (mmol g(-1)) and stocks (mmol m(-2)) in aboveground plant biomass in a large grassland biodiversity experiment (Jena Experiment). In the experiment including 60 temperate grassland species, plant diversity was manipulated as sown species richness (1, 2, 4, 8, 16) and richness and identity of plant functional groups (1-4; grasses, small herbs, tall herbs, legumes). We found positive species richness effects on Si as well as Ca stocks that were attributable to increased biomass production. The presence of particular functional groups was the most important factor explaining variation in aboveground Si and Ca stocks (mmol m(-2)). Grass presence increased the Si stocks by 140 % and legume presence increased the Ca stock by 230 %. Both the presence of specific plant functional groups and species diversity altered Si and Ca stocks, whereas Si and Ca concentration were affected mostly by the presence of specific plant functional groups. However, we found a negative effect of species diversity on Si and Ca accumulation, by calculating the deviation between mixtures and mixture biomass proportions, but in monoculture concentrations. These changes may in turn affect ecosystem processes such as plant litter decomposition and nutrient cycling in grasslands.

  17. Affect Response to Simulated Information Attack during Complex Task Performance

    DTIC Science & Technology

    2014-12-02

    main reasons for using an index such as this is that it can measure emotion based on a circular continuum or circumplex, when other measures can only...Austin, 2010). These results seem to be in agreement with the notion that “abstract reasoning intelligence” accounts for performance in...correlation between participants of average performance of the AF_MATB task conditions and choice/decision reaction time, abstract reasoning /planning

  18. 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.

  19. Which Peers Matter: How Social Ties Affect Peer-Group Effects

    ERIC Educational Resources Information Center

    Poldin, Oleg; Valeeva, Diliara; Yudkevich, Maria

    2016-01-01

    We study how the achievements of university students are influenced by the characteristics and achievements of peers in individuals' social networks. Defining peer group in terms of friendship and study partner ties enables us to apply a network regression model and thereby disentangle the influence of peers' performance from that of peers'…

  20. Which Peers Matter: How Social Ties Affect Peer-Group Effects

    ERIC Educational Resources Information Center

    Poldin, Oleg; Valeeva, Diliara; Yudkevich, Maria

    2016-01-01

    We study how the achievements of university students are influenced by the characteristics and achievements of peers in individuals' social networks. Defining peer group in terms of friendship and study partner ties enables us to apply a network regression model and thereby disentangle the influence of peers' performance from that of peers'…

  1. Fluid-Electrolyte-Mineral Interrelations as Affecting Work Performance.

    DTIC Science & Technology

    1985-11-01

    fiD-Ai65 325 FLUID-ELECTROLYTE-IIINERAL INTERRELATIONS AS AFFECTING 1/1 WORKC PERFORMRNCE(U) BOSTON UNIV MA SCHOOL OF MEDICINE M JANGHORRANI NOV 85...COMMAND Fort Detrick, Frederick, Maryland 21701-5012 Grant No. DAMD7-84-G-4012 BOSTON UNIVERSITY SCHOOL OF MEDICINE 85 E. NEWTON STREET, M1008 BOSTON...OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Boston University (If applicable) School of Medicine ..... 6c. ADDRESS (City, State, and ZIP Code) 7b

  2. Aversive Pavlovian Responses Affect Human Instrumental Motor Performance

    PubMed Central

    Rigoli, Francesco; Pavone, Enea Francesco; Pezzulo, Giovanni

    2012-01-01

    In neuroscience and psychology, an influential perspective distinguishes between two kinds of behavioral control: instrumental (habitual and goal-directed) and Pavlovian. Understanding the instrumental-Pavlovian interaction is fundamental for the comprehension of decision-making. Animal studies (as those using the negative auto-maintenance paradigm), have demonstrated that Pavlovian mechanisms can have maladaptive effects on instrumental performance. However, evidence for a similar effect in humans is scarce. In addition, the mechanisms modulating the impact of Pavlovian responses on instrumental performance are largely unknown, both in human and non-human animals. The present paper describes a behavioral experiment investigating the effects of Pavlovian conditioned responses on performance in humans, focusing on the aversive domain. Results showed that Pavlovian responses influenced human performance, and, similar to animal studies, could have maladaptive effects. In particular, Pavlovian responses either impaired or increased performance depending on modulator variables such as threat distance, task controllability, punishment history, amount of training, and explicit punishment expectancy. Overall, these findings help elucidating the computational mechanisms underlying the instrumental-Pavlovian interaction, which might be at the base of apparently irrational phenomena in economics, social behavior, and psychopathology. PMID:23060738

  3. Joint Attention Initiation with and without Positive Affect: Risk Group Differences and Associations with ASD Symptoms

    PubMed Central

    Gangi, Devon N.; Ibañez, Lisa V.; Messinger, Daniel S.

    2014-01-01

    Infants at risk for Autism Spectrum Disorders (ASD) may have difficulty integrating smiles into initiating joint attention (IJA) bids. A specific IJA pattern, anticipatory smiling, may communicate preexisting positive affect when an infant smiles at an object and then turns the smile toward the social partner. We compared the development of anticipatory smiling at 8, 10, and 12 months in infant siblings of children with ASD (high-risk siblings) and without ASD (low-risk siblings). High-risk siblings produced less anticipatory smiling than low-risk siblings, suggesting early differences in communicating preexisting positive affect. While early anticipatory smiling distinguished the risk groups, IJA not accompanied by smiling best predicted later severity of ASD-related behavioral characteristics among high-risk siblings. High-risk infants appear to show lower levels of motivation to share positive affect with others. However, facility with initiating joint attention in the absence of a clear index of positive affective motivation appears to be central to the prediction of ASD symptoms. PMID:24281421

  4. The Impact of Affect on Out-Group Judgments Depends on Dominant Information-Processing Styles: Evidence From Incidental and Integral Affect Paradigms.

    PubMed

    Isbell, Linda M; Lair, Elicia C; Rovenpor, Daniel R

    2016-04-01

    Two studies tested the affect-as-cognitive-feedback model, in which positive and negative affective states are not uniquely associated with particular processing styles, but rather serve as feedback about currently accessible processing styles. The studies extend existing work by investigating (a) both incidental and integral affect, (b) out-group judgments, and (c) downstream consequences. We manipulated processing styles and either incidental (Study 1) or integral (Study 2) affect and measured perceptions of out-group homogeneity. Positive (relative to negative) affect increased out-group homogeneity judgments when global processing was primed, but under local priming, the effect reversed (Studies 1 and 2). A similar interactive effect emerged on attributions, which had downstream consequences for behavioral intentions (Study 2). These results demonstrate that both incidental and integral affect do not directly produce specific processing styles, but rather influence thinking by providing feedback about currently accessible processing styles. © 2016 by the Society for Personality and Social Psychology, Inc.

  5. Improving the performance of indicator groups for the identification of important areas for species conservation.

    PubMed

    Larsen, Frank Wugt; Bladt, Jesper; Rahbek, Carsten

    2007-06-01

    Indicator groups may be important tools with which to guide the selection of networks of areas for conservation. Nevertheless, the literature provides little guidance as to what makes some groups of species more suitable than others to guide area selection. Using distributional data on all sub-Saharan birds and mammals, we assessed factors that influence the effectiveness of indicator groups. We assessed the influence of threatened, endemic, range-restricted, widespread, and large-bodied species by systematically varying their number in indicator groups. We also assessed the influence of taxonomic diversity by systematically varying the number of distinct genera and families within the indicator groups. We selected area networks based on the indicator groups and tested their ability to represent a set of species, which, in terms of species composition, is independent of the indicator group. Increasing the proportion of threatened, endemic, and range-restricted species in the indicator groups improved effectiveness of the selected area networks; in particular it improved the effectiveness in representing other threatened and range-restricted species. In contrast increasing the proportion of widespread and large-bodied species decreased effectiveness. Changes in the number of genera and families only marginally affected the performance of indicator groups. Our results reveal that a focus on species of special conservation concern, which are legitimate conservation targets in their own right, also improves the effectiveness of indicator groups, in particular in representing other species of conservation concern.

  6. 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.

  7. Environmental context change affects memory for performed actions.

    PubMed

    Sahakyan, Lili

    2010-03-01

    The current study investigated the effect of environmental context change between the study and test on the recall of action phrases that either were performed during encoding (subject-performed tasks, SPTs) or were verbally encoded (verbal tasks, VTs). Both SPTs and VTs showed the same magnitude of impaired recall when the study and test contexts mismatched. Furthermore, changing the context between the two study lists reduced cross-list intrusion errors compared to encoding the lists in the same context. Both SPTs and VTs benefited from studying the lists in different contexts as evidenced by reduced intrusions. Taken together, the results suggest that SPTs are integrated with their context because they suffered when context changed between the study and test, and they also benefited when they were performed in two environments versus the same environment.

  8. Plant species and functional group combinations affect green roof ecosystem functions.

    PubMed

    Lundholm, Jeremy; Macivor, J Scott; Macdougall, Zachary; Ranalli, Melissa

    2010-03-12

    Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. We used a replicated modular extensive (shallow growing- medium) green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or facilitation as mechanisms governing biodiversity-ecosystem functioning relationships in green

  9. Plant Species and Functional Group Combinations Affect Green Roof Ecosystem Functions

    PubMed Central

    Lundholm, Jeremy; MacIvor, J. Scott; MacDougall, Zachary; Ranalli, Melissa

    2010-01-01

    Background Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. Methodology/Principal Findings We used a replicated modular extensive (shallow growing- medium) green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. Conclusions/Significance Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or facilitation as mechanisms

  10. Youth perceptions of how neighborhood physical environment and peers affect physical activity: a focus group study.

    PubMed

    Smith, Alan L; Troped, Philip J; McDonough, Meghan H; DeFreese, J D

    2015-06-20

    There is need for a youth-informed conceptualization of how environmental and social neighborhood contexts influence physical activity. We assessed youths' perceptions of their neighborhood physical and peer environments as affecting physical activity. Thirty-three students (20 girls; ages 12-14 years) participated in focus groups about the physical environment and peers within their neighborhoods, and their understanding of how they affect physical activity. Inductive analysis identified themes of access (e.g., to equipment); aesthetics; physical and social safety; peer proximity and behavior (e.g., bullying); adult support or interference; and adult boundary setting. Participants also identified interconnections among themes, such as traffic shaping parent boundary setting and, in turn, access to physical spaces and peers. Young adolescents view neighborhoods in ways similar to and different from adults. Examining physical and social environments in tandem, while mindful of how adults shape and youth perceive these environments, may enhance understanding of youth physical activity behavior.

  11. Arrival order among native plant functional groups does not affect invasibility of constructed dune communities.

    PubMed

    Mason, T J; French, K; Jolley, D

    2013-10-01

    Different arrival order scenarios of native functional groups to a site may influence both resource use during development and final community structure. Arrival order may then indirectly influence community resistance to invasion. We present a mesocosm experiment of constructed coastal dune communities that monitored biotic and abiotic responses to different arrival orders of native functional groups. Constructed communities were compared with unplanted mesocosms. We then simulated a single invasion event by bitou (Chrysanthemoides monilifera ssp. rotundata), a dominant exotic shrub of coastal communities. We evaluated the hypothesis that plantings with simultaneous representation of grass, herb and shrub functional groups at the beginning of the experiment would more completely sequester resources and limit invasion than staggered plantings. Staggered plantings in turn would offer greater resource use and invasion resistance than unplanted mesocosms. Contrary to our expectations, there were few effects of arrival order on abiotic variables for the duration of the experiment and arrival order was unimportant in final community invasibility. All planted mesocosms supported significantly more invader germinants and significantly less invader abundance than unplanted mesocosms. Native functional group plantings may have a nurse effect during the invader germination and establishment phase and a competitive function during the invader juvenile and adult phase. Arrival order per se did not affect resource use and community invasibility in our mesocosm experiment. While grass, herb and shrub functional group plantings will not prevent invasion success in restored communities, they may limit final invader biomass.

  12. Management intensity and genetics affect loblolly pine seedling performance

    Treesearch

    Scott D. Roberts; Randall J. Rousseau; B. Landis Herrin

    2012-01-01

    Capturing potential genetic gains from tree improvement programs requires selection of the appropriate genetic stock and application of appropriate silvicultural management techniques. Limited information is available on how specific loblolly pine varietal genotypes perform under differing growing environments and management approaches. This study was established in...

  13. Factors Affecting Student Performance in Law School Economics Courses.

    ERIC Educational Resources Information Center

    Siegfried, John J.

    1981-01-01

    Noting the increasing role of economics in the law, many law schools have introduced formal economics instruction into their curricula. Several of the controversies surrounding liberal arts courses taught in law schools are examined. Prior formal coursework in the subject appeared to have no relationship to course performance. (MLW)

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. Physician group cultural dimensions and quality performance indicators: not all is equal.

    PubMed

    Smalarz, Amy

    2006-01-01

    A group practice culture survey measured the cultural dimensions of physician groups, and their relationship to group quality performance was explored. Cultural dimensions were statistically significant in explaining variance of quality performance among the physician groups studied. However, different cultural dimensions contributed to each of the quality performance indicators measured. Thus, cultural dimensions are important factors influencing physician groups' quality performance.

  3. Cognitive-affective symptoms of depression after myocardial infarction: different prognostic importance across age groups.

    PubMed

    Denollet, Johan; Freedland, Kenneth E; Carney, Robert M; de Jonge, Peter; Roest, Annelieke M

    2013-09-01

    Cognitive-affective symptoms of depression may not be as strongly related to prognosis after myocardial infarction (MI) as somatic depressive symptoms. Because it is not known whether this pattern of results is influenced by the age at which patients are diagnosed as having MI, we examined whether the importance of these symptoms is age dependent in the Enhancing Recovery in Coronary Heart Disease study. Patients with depression after MI (n = 1823) in the Enhancing Recovery in Coronary Heart Disease study were stratified into the following age groups: younger than 70 years (mean [standard deviation] = 55 [9.0] years) and 70 years or older (mean [standard deviation] = 76 [4.9] years). Measurements included demographic and clinical data and the Beck Depression Inventory. The end point was a composite of recurrent MI and mortality during a mean follow-up of 2.1 years. Patients 70 years or older had more severe manifestations of cardiac disease and somatic comorbidities than did patients younger than 70 years (p < .001). During follow-up, 456 patients died or had a recurrent MI. In patients 70 years or older, increasing age, disease severity, and comorbidities--but not depressive symptoms--independently predicted prognosis. In contrast, cognitive-affective symptoms of depression predicted death/MI in patients younger than 70 years (hazard ratio = 1.03, 95% confidence interval = 1.01-1.04, p = .011), after adjustment for disease severity and comorbidities. Somatic symptoms largely explained the link between cognitive-affective symptoms and adverse events, with the exception of hopelessness (hazard ratio = 1.47, 95% confidence interval = 1.11-1.95, p = .007), suggesting that somatic depressive symptoms accurately reflect the depressed mood state in this age group. Somatic symptoms and hopelessness independently predicted death/MI in MI patients younger than 70 years. Research needs to reexamine the modulating effect of age in studies on somatic and cognitive-affective

  4. Agility in Team Sports: Testing, Training and Factors Affecting Performance.

    PubMed

    Paul, Darren J; Gabbett, Tim J; Nassis, George P

    2016-03-01

    Agility is an important characteristic of team sports athletes. There is a growing interest in the factors that influence agility performance as well as appropriate testing protocols and training strategies to assess and improve this quality. The objective of this systematic review was to (1) evaluate the reliability and validity of agility tests in team sports, (2) detail factors that may influence agility performance, and (3) identify the effects of different interventions on agility performance. The review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We conducted a search of PubMed, Google Scholar, Science Direct, and SPORTDiscus databases. We assessed the methodological quality of intervention studies using a customized checklist of assessment criteria. Intraclass correlation coefficient values were 0.80-0.91, 0.10-0.81, and 0.81-0.99 for test time using light, video, and human stimuli. A low-level reliability was reported for youth athletes using the video stimulus (0.10-0.30). Higher-level participants were shown to be, on average, 7.5% faster than their lower level counterparts. Reaction time and accuracy, foot placement, and in-line lunge movement have been shown to be related to agility performance. The contribution of strength remains unclear. Efficacy of interventions on agility performance ranged from 1% (vibration training) to 7.5% (small-sided games training). Agility tests generally offer good reliability, although this may be compromised in younger participants responding to various scenarios. A human and/or video stimulus seems the most appropriate method to discriminate between standard of playing ability. Decision-making and perceptual factors are often propositioned as discriminant factors; however, the underlying mechanisms are relatively unknown. Research has focused predominantly on the physical element of agility. Small-sided games and video training may offer effective

  5. 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.

  6. 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.

  7. 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.

  8. Personality Factors Affecting Pilot Combat Performance: A Preliminary Investigation

    DTIC Science & Technology

    1997-09-01

    collected by personnel from Metrica , Inc., under Contract F33615-91-D-0010 (Delivery Order 0005) sponsored by the Air Force Armstrong Laboratory. The...authors would like to thank ’their colleagues at Metrica for their contributions to . this effort; in particular, Mr John Quebe and Mr Martin Dittmar...aircrew combat performance. San Antonio TX: Metrica Inc. 7 . Dolgin, D.L., & Gibb, G.D. (1988). Personality assessment in aviator selection (NAMRL

  9. 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

  10. Increased body weight affects academic performance in university students.

    PubMed

    Anderson, Angela S; Good, Deborah J

    2017-03-01

    For K-12 students, obesity has been linked to student educational achievements. The study objective was to determine whether academic performance in university students is correlated with BMI. Students from two consecutive academic years (Jan-May 2013 and Jan-May 2014) were given an optional class survey in May, as extra credit. Of the 452 students that completed the survey, 204 females and 75 males (N = 279; 73% female and 27% male) consented to participate in the study. The number of correct answers to problem-solving questions (PSQs) and the overall final grade for the class were compared to the calculated BMI using linear regression with a Pearson's R correlation and unpaired t-tests. BMI was significantly negatively correlated with student's final grades (P = 0.001 Pearson's r = - 0.190) and PSQs were positively correlated with final grades (P < 0.001; Pearson's r = 0.357). Our findings show a correlation between healthy body weight and improved academic performance. Further, the data suggest that future research in the area of body weight, diet, and exercise and any correlations of these with academic performance in college students are warranted.

  11. Eating in groups: Do multiple social influences affect intake in a fast-food restaurant?

    PubMed

    Brindal, Emily; Wilson, Carlene; Mohr, Philip; Wittert, Gary

    2015-05-01

    This study investigated multiple social influences to determine whether they affect amount eaten at a fast-food environment. Using observational methods, data on meal duration, foods eaten and personal characteristics were collected for 157 McDonald's patrons. Analysis of covariance revealed that female diners ate less kilojoules when eating in mixed- versus same-sex groups (adjusted difference = 967 kJ, p < .05), while male diners eating in mixed-sex company ate more in groups compared to pairs (adjusted difference = 1067 kJ, p = .019). Influences to increase and restrict the amount eaten can operate simultaneously in an eating environment with gender a critical factor for consideration.

  12. Group Comparisons of Mathematics Performance from a Cognitive Diagnostic Perspective

    ERIC Educational Resources Information Center

    Chen, Yi-Hsin; Ferron, John M.; Thompson, Marilyn S.; Gorin, Joanna S.; Tatsuoka, Kikumi K.

    2010-01-01

    Traditional comparisons of test score means identify group differences in broad academic areas, but fail to provide substantive description of how the groups differ on the specific cognitive attributes required for success in the academic area. The rule space method (RSM) allows for group comparisons at the cognitive attribute level, which…

  13. Group Creativity: Musical Performance and Collaboration Psychology of Music

    ERIC Educational Resources Information Center

    Sawyer, R. Keith

    2006-01-01

    In this article, I focus on three defining characteristics of group creativity: improvisation, collaboration and emergence. To demonstrate these three characteristics, I present several examples of group creativity in both music and theater. Then I explore how structure and improvisation are always both present in group creativity. Improvisations…

  14. Can salt on an optical rain gauge lens affect performance?

    NASA Technical Reports Server (NTRS)

    Bliven, Larry F.

    1994-01-01

    The optical rain gauge (ORG) by ScTI is designed to be tolerant to reduction of infrared beam intensity due to a dirty lens. Recently there is interest in long term use of optical gauges onboard buoys at sea. Because of logistics, these systems are serviced infrequently, i.e., every several months. Due to the proximity of the gauges to the sea surface, salt can be expected to be deposited on the lens. To obtain an indication of the potential for dirty lens to affect the ORG calibration, two simple experiments were conducted. In the control experiment, a sample ORG was compared to three other ORG's during natural rain events. Next a translucent mask was placed on the transmitter lens of the sample ORG and again data were collected under natural rain conditions. The mask reduced the gain of the perturbed ORG by about 30%. The perturbed ORG operated rather well in that the mask only causes a change in the gain and does not cause data drop out at low rain rates. However, the reduced gain would seriously impact an assessment of rain statistics.

  15. Volumetric breast density affects performance of digital screening mammography.

    PubMed

    Wanders, Johanna O P; Holland, Katharina; Veldhuis, Wouter B; Mann, Ritse M; Pijnappel, Ruud M; Peeters, Petra H M; van Gils, Carla H; Karssemeijer, Nico

    2017-02-01

    To determine to what extent automatically measured volumetric mammographic density influences screening performance when using digital mammography (DM). We collected a consecutive series of 111,898 DM examinations (2003-2011) from one screening unit of the Dutch biennial screening program (age 50-75 years). Volumetric mammographic density was automatically assessed using Volpara. We determined screening performance measures for four density categories comparable to the American College of Radiology (ACR) breast density categories. Of all the examinations, 21.6% were categorized as density category 1 ('almost entirely fatty') and 41.5, 28.9, and 8.0% as category 2-4 ('extremely dense'), respectively. We identified 667 screen-detected and 234 interval cancers. Interval cancer rates were 0.7, 1.9, 2.9, and 4.4‰ and false positive rates were 11.2, 15.1, 18.2, and 23.8‰ for categories 1-4, respectively (both p-trend < 0.001). The screening sensitivity, calculated as the proportion of screen-detected among the total of screen-detected and interval tumors, was lower in higher density categories: 85.7, 77.6, 69.5, and 61.0% for categories 1-4, respectively (p-trend < 0.001). Volumetric mammographic density, automatically measured on digital mammograms, impacts screening performance measures along the same patterns as established with ACR breast density categories. Since measuring breast density fully automatically has much higher reproducibility than visual assessment, this automatic method could help with implementing density-based supplemental screening.

  16. Review of factors affecting aircraft wet runway performance

    NASA Technical Reports Server (NTRS)

    Yager, T. J.

    1983-01-01

    Problems associated with aircraft operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from investigations conducted at the Langley Aircraft Landing Loads and Traction Facility and from tests with instrumented ground vehicles and aircraft are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

  17. Functional groups affect physical and biological properties of dextran-based hydrogels.

    PubMed

    Sun, Guoming; Shen, Yu-I; Ho, Chia Chi; Kusuma, Sravanti; Gerecht, Sharon

    2010-06-01

    Modification of dextran backbone allows the development of a hydrogel with specific characteristics. To enhance their functionality for tissue-engineered scaffolds, a series of dextran-based macromers was synthesized by incorporating various functional groups, including allyl isocyanate (Dex-AI), ethylamine (Dex-AE), chloroacetic acid (Dex-AC), or maleic-anhydride (Dex-AM) into dextrans. The dextran-based biodegradable hybrid hydrogels are developed by integrating polyethylene glycol diacrylate (PEGDA). To explore the effect of different derivatives on hydrogel properties, three different ratios of Dex/PEGDA are examined: low (20/80), medium (40/60), and high (60/40). Differences in physical and biological properties of the hydrogels are found, including swelling, degradation rate, mechanics, crosslinking density, biocompatibility (in vitro and in vivo), and vascular endothelial growth factor release. The results also indicate that the incorporation of amine groups into dextran gives rise to hydrogels with better biocompatible and release properties. We, therefore, conclude that the incorporation of different functional groups affects the fundamental properties of a dextran-based hydrogel network, and that amine groups are preferred to generate hydrogels for biomedical use.

  18. Using a Feedback Environment to Improve Creative Performance: A Dynamic Affect Perspective

    PubMed Central

    Gong, Zhenxing; Zhang, Na

    2017-01-01

    Prior research on feedback and creative performance has neglected the dynamic nature of affect and has focused only on the influence of positive affect. We argue that creative performance is the result of a dynamic process in which a person experiences a phase of negative affect and subsequently enters a state of high positive affect that is influenced by the feedback environment. Hierarchical regression was used to analyze a sample of 264 employees from seven industry firms. The results indicate that employees’ perceptions of a supportive supervisor feedback environment indirectly influence their level of creative performance through positive affect (t2); the negative affect (t1) moderates the relationship between positive affect (t2) and creative performance (t2), rendering the relationship more positive if negative affect (t1) is high. The change in positive affect mediates the relationship between the supervisor feedback environment and creative performance; a decrease in negative affect moderates the relationship between increased positive affect and creative performance, rendering the relationship more positive if the decrease in negative affect is large. The implications for improving the creative performances of employees are further discussed. PMID:28861025

  19. 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.

  20. Modelling group navigation: transitive social structures improve navigational performance.

    PubMed

    Flack, Andrea; Biro, Dora; Guilford, Tim; Freeman, Robin

    2015-07-06

    Collective navigation demands that group members reach consensus on which path to follow, a task that might become more challenging when the group's members have different social connections. Group decision-making mechanisms have been studied successfully in the past using individual-based modelling, although many of these studies have neglected the role of social connections between the group's interacting members. Nevertheless, empirical studies have demonstrated that individual recognition, previous shared experiences and inter-individual familiarity can influence the cohesion and the dynamics of the group as well as the relative spatial positions of specific individuals within it. Here, we use models of collective motion to study the impact of social relationships on group navigation by introducing social network structures into a model of collective motion. Our results show that groups consisting of equally informed individuals achieve the highest level of accuracy when they are hierarchically organized with the minimum number of preferred connections per individual. We also observe that the navigational accuracy of a group will depend strongly on detailed aspects of its social organization. More specifically, group navigation does not only depend on the underlying social relationships, but also on how much weight leading individuals put on following others. Also, we show that groups with certain social structures can compensate better for an increased level of navigational error. The results have broader implications for studies on collective navigation and motion because they show that only by considering a group's social system can we fully elucidate the dynamics and advantages of joint movements.

  1. 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. © The Author(s) 2016.

  2. Statistical performance of cladistic strategies for haplotype grouping in pharmacogenetics.

    PubMed

    Lunceford, Jared K; Liu, Nancy

    2008-12-10

    Haplotypes comprising multiple single nucleotide polymorphisms (SNPs) are popular covariates for capturing the key genetic variation present over a region of interest in the DNA sequence. Although haplotypes can provide a clearer assessment of genetic variation in a region than their component SNPs considered individually, the multi-allelic nature of haplotypes increases the complexity of the statistical models intended to discover association with outcomes of interest. Cladistic methods cluster haplotypes according to the estimates of their genealogical closeness and have been proposed recently as strategies for reducing model complexity and increasing power. Two examples are methods based on a haplotype nesting algorithm described by Templeton et al. (Genetics 1987; 117:343-351) and hierarchical clustering of haplotypes as described by Durrant et al. (Am. J. Hum. Genet. 2004; 75:35-43). In the context of assessing the pharmacogenetic effects of candidate genes, for which high-density SNP data have been gathered, we have conducted a simulation-based case study of the testing and estimation properties of two strategies based on Templeton's algorithm (TA), one being that described by Seltman et al. (Am. J. Hum. Genet. 2001; 68:1250-1263; Genet. Epidemiol. 2003; 25:48-58), as well as the method of Durrant et al. using data from a diabetes clinical trial. Even after adjusting for multiplicity, improvements in power can be realized using cladistic approaches with treatment group sizes in the range expected for standard trials, although these gains may be sensitive to the cladistic structure used. Differences in the relative performance of the cladistic approaches examined were observed with the clustering approach of Durrant et al. showing statistical properties superior to the methods based on TA.

  3. Investigation of Factors Affecting Aerodynamic Performance of Nebulized Nanoemulsion

    PubMed Central

    Kamali, Hosein; Abbasi, Shayan; Amini, Mohammad Ali; Amani, Amir

    2016-01-01

    This work aimed to prepare a nanoemulsion preparation containing budesonide and assess its aerodynamic behavior in comparison with suspension of budesonide. In-vitro aerodynamic performance of the corresponding micellar solution (ie. nanoemulsion preparation without oil) was investigated too. Nanoemulsions of almond oil containing budesonide, as a hydrophobic model drug molecule, were prepared and optimized. Then, the effect of variation of surfactant/co-surfactant concentration on the aerodynamic properties of the nebulized aerosol was studied. The results indicated that the most physically stable formulation makes the smallest aerodynamic size. The concentration of co-surfactant was also shown to be critical in determination of aerodynamic size. Furthermore, the optimized sample, with 3% w/w almond oil, 20% w/w Tween 80+Span 80 and 2% w/w ethanol showed a smaller MMAD in comparison with the commercially available suspension and the micellar solution. PMID:28243265

  4. 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.

  5. 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.

  6. Affecting Factors on the Performance of Community Health Workers in Iran's Rural Areas: A Review Article.

    PubMed

    Salehi Zalani, Gholamhossein; Bayat, Mahboubeh; Shokri, Azad; Mirbahaeddin, S Elmira; Rasi, Vahid; Alirezaei, Samira; Manafi, Fatemeh

    2016-11-01

    This study aimed to use a mixed-method approach to investigate affecting factors on the performance of Community Health Workers (CHW) in Iran's villages. This study was conducted during 2014-2015 with a mixed method in three phases of literature review, Delphi technique and developing a rich picture. Overall, in order to finalize the affecting factors and their relationships between qualitative content analysis, Delphi technique, AHP technique and Focus Group Discussion were used, respectively. Affecting factors on CHW performance were divided into four main categories, 10 sub-themes and 35 contents. Increase in the level of people's awareness, disease patterns, demographic structure and lifestyle were placed in four priorities respectively on the basis of importance. To the most extent CHW cannot face current needs of rural communities. It challenges equitable access to healthcare services and also conflicts with the primary philosophy of CHW presence in rural areas. CHW can be used in two forms; either as an assistant to rural family physicians or with the same previous functions.

  7. Task-irrelevant spider associations affect categorization performance.

    PubMed

    Woud, Marcella L; Ellwart, Thomas; Langner, Oliver; Rinck, Mike; Becker, Eni S

    2011-09-01

    In two studies, the Single Target Implicit Association Test (STIAT) was used to investigate automatic associations toward spiders. In both experiments, we measured the strength of associations between pictures of spiders and either threat-related words or pleasant words. Unlike previous studies, we administered a STIAT version in which stimulus contents was task-irrelevant: The target spider pictures were categorized according to the label picture, irrespective of what they showed. In Study 1, spider-fearful individuals versus non-fearful controls were tested, Study 2 compared spider enthusiasts to non-fearful controls. Results revealed that the novel STIAT version was sensitive to group differences in automatic associations toward spiders. In Study 1, it successfully distinguished between spider-fearful individuals and non-fearful controls. Moreover, STIAT scores predicted automatic fear responses best, whereas controlled avoidance behavior was best predicted by the FAS (German translation of the Fear of Spiders Questionnaire). The results of Study 2 demonstrated that the novel STIAT version was also able to differentiate between spider enthusiasts and non-fearful controls.

  8. Assessment of Factor Affecting Institutional Performance: The Case of Wolaita Sodo University

    ERIC Educational Resources Information Center

    Shibru, Sintayehu; Bibiso, Mesfin; Ousman, Kedir

    2017-01-01

    The purpose of this study is to explore factors that affect institutional performance of Wolaita Sodo University. The study has identified middle level manager's perceptions toward institutional performance to indicate the key factors that seem to affect the performance of the university. Data were collected using structured questionnaires and…

  9. Work duration does not affect cortisol output in experienced firefighters performing live burn drills.

    PubMed

    Rosalky, Deena S; Hostler, David; Webb, Heather E

    2017-01-01

    Work duration may affect firefighters' stress responses. Forty-two firefighters (38 males) performed either 2 (SWD) or 3 (LWD) bouts of simulated fire suppression activity. Salivary cortisol, self-reported fear and anxiety, and perceptual thermal responses were measured. Cortisol was evaluated using area-under-the-curve calculations (Pruessner et al., 2003). Affective responses between the two conditions were compared using T-tests. Pearson product moment correlations were used to analyze the relationships between affect and change in thermal load perception. Cortisol decreased across the protocol in both groups, and no difference was found in cortisol or affect between the groups. Cortisol decreased (F4,36 = 3.43, p < 0.05) in the SWD group from a mean concentration of 40.93 ± 11.41 nmol/L to 25.07 ± 9.88 nmol/L at the end of the protocol. In the LWD group, the mean cortisol concentration decreased from 42.89 ± 11.83 to 25.07 ± 8.82 at the end of the protocol (F5,50 = 14.77, p < 0.01). Anxiety increased in the LWD (F4,72 = 5.11, p = 0.001) but not the SWD group. Fear increased in the SWD (F3,48 = 14.15, p < 0.001) and LWD group (F4,60 = 4.47, p < 0.01). The present findings suggests a moderate fear load with firefighting, which appears not to be associated with duration of work bout. Examination of more varied work bout lengths may reveal an association between anxiety and work duration. However, the work bout durations investigated in the current study comprise the range of what is practical from an occupational standpoint and the physiological capabilities of the firefighters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Analysis of postural control and muscular performance in young and elderly women in different age groups.

    PubMed

    Gomes, Matheus M; Reis, Júlia G; Carvalho, Regiane L; Tanaka, Erika H; Hyppolito, Miguel A; Abreu, Daniela C C

    2015-01-01

    muscle strength and power are two factors affecting balance. The impact of muscle strength and power on postural control has not been fully explored among different age strata over sixty. the aim of the present study was to assess the muscle strength and power of elderly women in different age groups and determine their correlation with postural control. eighty women were divided into four groups: the young 18-30 age group (n=20); the 60-64 age group (n=20); the 65-69 age group (n=20); and the 70-74 age group (n=20). The participants underwent maximum strength (one repetition maximum or 1-RM) and muscle power tests to assess the knee extensor and flexor muscles at 40%, 70%, and 90% 1-RM intensity. The time required by participants to recover their balance after disturbing their base of support was also assessed. the elderly women in the 60-64, 65-69, and 70-74 age groups exhibited similar muscle strength, power, and postural control (p>0.05); however, these values were lower than those of the young group (p<0.05) as expected. There was a correlation between muscle strength and power and the postural control performance (p<0.05). despite the age difference, elderly women aged 60 to 74 years exhibited similar abilities to generate strength and power with their lower limbs, and this ability could be one factor that explains the similar postural control shown by these women.

  11. Inferior parietal rtms affects performance in an addition task.

    PubMed

    Göbell, Silke M; Rushworth, Matthew F; Walsh, Vincent

    2006-07-01

    Neuropsychological and neuroimaging studies strongly suggest that the inferior parietal cortex is important for calculation. However, the evidence from neuroimaging experiments for a left hemispheric dominance in calculation is not as clear as one would expect from the studies of patients. Often a concomitant activation of the homologous inferior parietal region of the right hemisphere is reported in the same tasks. The objective of this study was to replicate basic findings of acalculic patients and to investigate discrepancies between data from patients and results from neuroimaging studies in an addition task. Repetitive transcranial magnetic stimulation (rTMS) was applied over inferior parietal areas and the adjacent intraparietal sulcus (IPS) while subjects solved double-digit addition tasks. From studies of acalculic patients it was hypothesised that left hemispheric rTMS stimulation should result in longer reaction times (RTs) in the addition task. On addition trials without TMS subjects showed the classical problem size effect with longer RTs the larger the sum of the two operands. Magnetic stimulation over left inferior parietal areas disrupted performance significantly. The effect was specific to the left hemisphere stimulation. There was no increase in RTs for rTMS stimulation over the right hemisphere.

  12. 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.

  13. What Makes a "Good Group"? Exploring the Characteristics and Performance of Undergraduate Student Groups

    ERIC Educational Resources Information Center

    Channon, S. B.; Davis, R. C.; Goode, N. T.; May, S. A.

    2017-01-01

    Group work forms the foundation for much of student learning within higher education, and has many educational, social and professional benefits. This study aimed to explore the determinants of success or failure for undergraduate student teams and to define a "good group" through considering three aspects of group success: the task, the…

  14. What Makes a "Good Group"? Exploring the Characteristics and Performance of Undergraduate Student Groups

    ERIC Educational Resources Information Center

    Channon, S. B.; Davis, R. C.; Goode, N. T.; May, S. A.

    2017-01-01

    Group work forms the foundation for much of student learning within higher education, and has many educational, social and professional benefits. This study aimed to explore the determinants of success or failure for undergraduate student teams and to define a "good group" through considering three aspects of group success: the task, the…

  15. Improving Performance for Gifted Students in a Cluster Grouping Model

    ERIC Educational Resources Information Center

    Brulles, Dina; Saunders, Rachel; Cohn, Sanford J.

    2010-01-01

    Although experts in gifted education widely promote cluster grouping gifted students, little empirical evidence is available to attest to its effectiveness. This study is an example of comparative action research in the form of a quantitative case study that focused on the mandated cluster grouping practices for gifted students in an urban…

  16. Supervision and Group Performance; Instructor's Guide: Interagency Training Program.

    ERIC Educational Resources Information Center

    Civil Service Commission, Washington, DC. Bureau of Training.

    The instructor's guide to the course designed to acquaint supervisors, with such behavioral science theories as motivation, leadership, group dynamics, and change, stresses student participation through group discussion, role-playing, incident-process case discussion, and management simulation or games. The course is organized around four themes…

  17. 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. © 2014 The Author(s).

  18. An evaluation of some factors affecting the detection of blood group antibodies by automated methods.

    PubMed

    Kolberg, J; Nordhagen, R

    1975-01-01

    Some factors affecting the sensitivity of the automated methods for blood group antibody detection have been evaluated. The experiments revealed influencing differences between various albumin preparations. In the BMC method, one lot of albumin permitted no significant antibody detection. In the LISP technique, a plateau of maximum Polybrene activity was found. The beginning of this plateau depended on both the albumin preparation and the Polybrene lot. In the BMC method, methyl cellulose gave optimal sensitivity within a concentration range of 0.3 to 0.5 per cent. The stability of test cells stored in ACD at 4 C was studied. All test cells could be used safely up to two weeks. Cells from different donors showed variable reactivity after three weeks.

  19. Dream interpretation, affect, and the theory of neuronal group selection: Freud, Winnicott, Bion, and Modell.

    PubMed

    Shields, Walker

    2006-12-01

    The author uses a dream specimen as interpreted during psychoanalysis to illustrate Modell's hypothesis that Edelman's theory of neuronal group selection (TNGS) may provide a valuable neurobiological model for Freud's dynamic unconscious, imaginative processes in the mind, the retranscription of memory in psychoanalysis, and intersubjective processes in the analytic relationship. He draws parallels between the interpretation of the dream material with keen attention to affect-laden meanings in the evolving analytic relationship in the domain of psychoanalysis and the principles of Edelman's TNGS in the domain of neurobiology. The author notes how this correlation may underscore the importance of dream interpretation in psychoanalysis. He also suggests areas for further investigation in both realms based on study of their interplay.

  20. When sound affects vision: effects of auditory grouping on visual motion perception.

    PubMed

    Watanabe, K; Shimojo, S

    2001-03-01

    Two identical visual targets moving across each other can be perceived either to bounce off or to stream through each other. A brief sound at the moment the targets coincide biases perception toward bouncing. We found that this bounce-inducing effect was attenuated when other identical sounds (auditory flankers) were presented 300 ms before and after the simultaneous sound. The attenuation occurred only when the simultaneous sound and auditory flankers had similar acoustic characteristics and the simultaneous sound was not salient. These results suggest that there is an aspect of auditory-grouping (saliency-assigning) processes that is context-sensitive and can be utilized by the visual system for solving ambiguity. Furthermore, control experiments revealed that such auditory context did not affect the perceptual qualities of the simultaneous sound. Because the attenuation effect is not manifest in the perception of acoustic characteristics of individual sound elements, we conclude that it is a genuine cross-modal effect.

  1. Rhynchophorus ferrugineus attack affects a group of compounds rather than rearranging Phoenix canariensis metabolic pathways.

    PubMed

    Giovino, Antonio; Martinelli, Federico; Saia, Sergio

    2016-04-01

    The red palm weevil (RPW; Rhynchophorus ferrugineus) is spreading worldwide and severely harming many palm species. However, most studies on RPW focused on insect biology, and little information is available about the plant response to the attack. In the present experiment, we used metabolomics to study the alteration of the leaf metabolome of Phoenix canariensis at initial (1st stage) or advanced (2nd stage) attack by RPW compared with healthy (unattacked) plants. The leaf metabolome significantly varied among treatments. At the 1st stage of attack, plants showed a reprogramming of carbohydrate and organic acid metabolism; in contrast, peptides and lipid metabolic pathways underwent more changes during the 2nd than 1st stage of attack. Enrichment metabolomics analysis indicated that RPW attack mostly affected a particular group of compounds rather than rearranging plant metabolic pathways. Some compounds selectively affected during the 1st rather than 2nd stage (e.g. phenylalanine; tryptophan; cellobiose; xylose; quinate; xylonite; idonate; and iso-threonate; cellobiotol and arbutine) are upstream events in the phenylpropanoid, terpenoid and alkaloid biosynthesis. These compounds could be designated as potential markers of initial RPW attack. However, further investigation is needed to determine efficient early screening methods of RPW attack based on the concentrations of these molecules.

  2. Social learning strategies modify the effect of network structure on group performance

    PubMed Central

    Barkoczi, Daniel; Galesic, Mirta

    2016-01-01

    The structure of communication networks is an important determinant of the capacity of teams, organizations and societies to solve policy, business and science problems. Yet, previous studies reached contradictory results about the relationship between network structure and performance, finding support for the superiority of both well-connected efficient and poorly connected inefficient network structures. Here we argue that understanding how communication networks affect group performance requires taking into consideration the social learning strategies of individual team members. We show that efficient networks outperform inefficient networks when individuals rely on conformity by copying the most frequent solution among their contacts. However, inefficient networks are superior when individuals follow the best member by copying the group member with the highest payoff. In addition, groups relying on conformity based on a small sample of others excel at complex tasks, while groups following the best member achieve greatest performance for simple tasks. Our findings reconcile contradictory results in the literature and have broad implications for the study of social learning across disciplines. PMID:27713417

  3. Social learning strategies modify the effect of network structure on group performance

    NASA Astrophysics Data System (ADS)

    Barkoczi, Daniel; Galesic, Mirta

    2016-10-01

    The structure of communication networks is an important determinant of the capacity of teams, organizations and societies to solve policy, business and science problems. Yet, previous studies reached contradictory results about the relationship between network structure and performance, finding support for the superiority of both well-connected efficient and poorly connected inefficient network structures. Here we argue that understanding how communication networks affect group performance requires taking into consideration the social learning strategies of individual team members. We show that efficient networks outperform inefficient networks when individuals rely on conformity by copying the most frequent solution among their contacts. However, inefficient networks are superior when individuals follow the best member by copying the group member with the highest payoff. In addition, groups relying on conformity based on a small sample of others excel at complex tasks, while groups following the best member achieve greatest performance for simple tasks. Our findings reconcile contradictory results in the literature and have broad implications for the study of social learning across disciplines.

  4. Social learning strategies modify the effect of network structure on group performance.

    PubMed

    Barkoczi, Daniel; Galesic, Mirta

    2016-10-07

    The structure of communication networks is an important determinant of the capacity of teams, organizations and societies to solve policy, business and science problems. Yet, previous studies reached contradictory results about the relationship between network structure and performance, finding support for the superiority of both well-connected efficient and poorly connected inefficient network structures. Here we argue that understanding how communication networks affect group performance requires taking into consideration the social learning strategies of individual team members. We show that efficient networks outperform inefficient networks when individuals rely on conformity by copying the most frequent solution among their contacts. However, inefficient networks are superior when individuals follow the best member by copying the group member with the highest payoff. In addition, groups relying on conformity based on a small sample of others excel at complex tasks, while groups following the best member achieve greatest performance for simple tasks. Our findings reconcile contradictory results in the literature and have broad implications for the study of social learning across disciplines.

  5. Functional performance testing in participants with functional ankle instability and in a healthy control group.

    PubMed

    Buchanan, Amanda S; Docherty, Carrie L; Schrader, John

    2008-01-01

    Functional ankle instability (FAI) affects a large part of the population. Inconsistent findings have been reported regarding the existence of functional performance deficits in individuals with FAI. To examine functional performance in participants with FAI compared with participants in a control group during 2 hopping tests. Case-control study. Athletic training research laboratory. There were 40 college-aged individuals who participated in our study: 20 with FAI and 20 without FAI. We defined FAI as history of an ankle sprain and residual episodes of "giving way." Participants completed 2 functional performance tests (FPTs): the single-limb hopping and the single-limb hurdle tests. Time to complete each test was recorded. Following each FPT, participants were asked if their ankles felt unstable during the test. We found no difference between participants in the FAI and control groups for the hopping or hurdle tests (P > .05). When asked if their ankles felt unstable during the FPTs, approximately half of the participants in the FAI group and none of the participants in the control group reported a feeling of instability. Subsequently, a secondary analysis of variance was calculated with participants grouped into 3 categories: control participants, FAI participants reporting instability symptoms during FPT (FAI-S), and FAI participants not reporting instability symptoms during FPT (FAI-NS). Results revealed a difference among the 3 groups for the single-limb hopping test (P < .01). Post hoc analysis revealed a difference between the FAI-S participants and both the control and the FAI-NS participants. No difference was identified for the single-limb hurdle test (P = .41). The FAI-S participants had performance deficits during the single-limb hopping test. Therefore, clinicians could use this simple hopping test as an additional method to determine the presence of FAI.

  6. Effects of incentives on psychosocial performances in simulated space-dwelling groups

    NASA Astrophysics Data System (ADS)

    Hienz, Robert D.; Brady, Joseph V.; Hursh, Steven R.; Gasior, Eric D.; Spence, Kevin R.; Emurian, Henry H.

    Prior research with individually isolated 3-person crews in a distributed, interactive, planetary exploration simulation examined the effects of communication constraints and crew configuration changes on crew performance and psychosocial self-report measures. The present report extends these findings to a model of performance maintenance that operationalizes conditions under which disruptive affective responses by crew participants might be anticipated to emerge. Experiments evaluated the effects of changes in incentive conditions on crew performance and self-report measures in simulated space-dwelling groups. Crews participated in a simulated planetary exploration mission that required identification, collection, and analysis of geologic samples. Results showed that crew performance effectiveness was unaffected by either positive or negative incentive conditions, while self-report measures were differentially affected—negative incentive conditions produced pronounced increases in negative self-report ratings and decreases in positive self-report ratings, while positive incentive conditions produced increased positive self-report ratings only. Thus, incentive conditions associated with simulated spaceflight missions can significantly affect psychosocial adaptation without compromising task performance effectiveness in trained and experienced crews.

  7. 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…

  8. Using the Competent Small Group Communicator Instrument to Assess Group Performance in the Classroom.

    ERIC Educational Resources Information Center

    Albert, Lawrence S.

    If being a competent small group problem solver is difficult, it is even more difficult to impart those competencies to others. Unlike athletic coaches who are near their players during the real game, teachers of small group communication are not typically present for on-the-spot coaching when their students are doing their problem solving. That…

  9. Job Satisfaction and Organizational Commitment: Affective Commitment Predictors in a Group of Professionals

    NASA Astrophysics Data System (ADS)

    Ferretti, Maria Santa

    Job satisfaction and organizational commitment have long been identified as relevant factors for the well-being of individuals within an organization and the success of the organization itself. As the well-being can be, in principle, considered as emergent from the influence of a number of factors, the main goal of a theory of organizations is to identify these factors and the role they can play. In this regard job satisfaction and organizational commitment have been often identified with structural factors allowing an organization to be considered as a system, or a wholistic entity, rather than a simple aggregate of individuals. Furthermore, recent studies have shown that job satisfaction has a significant, direct effect on determining individuals' attachment to an organization and a significant but indirect effect on their intention to leave a company. However, a complete assessment of the role of these factors in establishing and keeping the emergence of an organization is still lacking, due to shortage of measuring instruments and to practical difficulties in interviewing organization members. The present study aims to give a further contribution to what is currently known about the relationship between job satisfaction and affective commitment by using a group of professionals, all at management level. A questionnaire to measure these constructs, following a pilot study, was designed and administered to 1042 participants who were all professionals and had the title of industrial manager or director. The factors relating to job satisfaction and the predictive value of these factors (to predict an employee's emotional involvement with their organization) were simultaneously tested by a confirmative factorial model. The results were generalized with a multi-sample procedure by using models of structural equations. This procedure was used to check whether these factors could be considered or not as causes producing the measured affective commitment. The results

  10. Detailed Performance Calculations: Georgia Institute of Technology Group, Appendix E

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Conditions for system intercomparison; signal strength evaluation; background total source strength; signal-to-noise ratio; performance of present Georgia Tech system; and special comments on current Georgia Tech system are discussed.

  11. Distributed communication and psychosocial performance in simulated space dwelling groups

    NASA Astrophysics Data System (ADS)

    Hienz, R. D.; Brady, J. V.; Hursh, S. R.; Ragusa, L. C.; Rouse, C. O.; Gasior, E. D.

    2005-05-01

    The present report describes the development and application of a distributed interactive multi-person simulation in a computer-generated planetary environment as an experimental test bed for modeling the human performance effects of variations in the types of communication modes available, and in the types of stress and incentive conditions underlying the completion of mission goals. The results demonstrated a high degree of interchangeability between communication modes (audio, text) when one mode was not available. Additionally, the addition of time pressure stress to complete tasks resulted in a reduction in performance effectiveness, and these performance reductions were ameliorated via the introduction of positive incentives contingent upon improved performances. The results obtained confirmed that cooperative and productive psychosocial interactions can be maintained between individually isolated and dispersed members of simulated spaceflight crews communicating and problem-solving effectively over extended time intervals without the benefit of one another's physical presence.

  12. Detailed Performance Calculations: Georgia Institute of Technology Group, Appendix E

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Conditions for system intercomparison; signal strength evaluation; background total source strength; signal-to-noise ratio; performance of present Georgia Tech system; and special comments on current Georgia Tech system are discussed.

  13. Intimate Partner Violence and Its Health Impact on Disproportionately Affected Populations, Including Minorities and Impoverished Groups

    PubMed Central

    Hayashi, Hitomi; Campbell, Jacquelyn C.

    2015-01-01

    Abstract In the United States, intimate partner violence (IPV) against women disproportionately affects ethnic minorities. Further, disparities related to socioeconomic and foreign-born status impact the adverse physical and mental health outcomes as a result of IPV, further exacerbating these health consequences. This article reviews 36 U.S. studies on the physical (e.g., multiple injuries, disordered eating patterns), mental (e.g., depression, post-traumatic stress disorder), and sexual and reproductive health conditions (e.g., HIV/STIs, unintended pregnancy) resulting from IPV victimization among ethnic minority (i.e., Black/African American, Hispanic/Latina, Native American/Alaska Native, Asian American) women, some of whom are immigrants. Most studies either did not have a sufficient sample size of ethnic minority women or did not use adequate statistical techniques to examine differences among different racial/ethnic groups. Few studies focused on Native American/Alaska Native and immigrant ethnic minority women and many of the intra-ethnic group studies have confounded race/ethnicity with income and other social determinants of health. Nonetheless, of the available data, there is evidence of health inequities associated with both minority ethnicity and IPV. To appropriately respond to the health needs of these groups of women, it is necessary to consider social, cultural, structural, and political barriers (e.g., medical mistrust, historical racism and trauma, perceived discrimination, immigration status) to patient–provider communication and help-seeking behaviors related to IPV, which can influence health outcomes. This comprehensive approach will mitigate the racial/ethnic and socioeconomic disparities related to IPV and associated health outcomes and behaviors. PMID:25551432

  14. The Effects of T-Group Training and Group Video Recall Procedures on Affective Sensitivity, Openmindedness and Self-Perception Change in Counselors.

    ERIC Educational Resources Information Center

    Cerra, Patrick Frank

    This study investigated the relative effect of T group training and Group Video Recall (GVR) procedures in the growth of affective sensitivity, openmindedness, and self-perception in 17 Indiana University students majoring or minoring in Counseling and Guidance. Relationships among the three behaviors were also sought. The Rokeach Dogmatism Scale…

  15. 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

    ... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Performance Test Requirements for HCl... Requirements for HCl Production Affected Sources As stated in § 63.9020, you must comply with the following requirements for performance tests for HCl production for each affected source. For each HCl process vent...

  16. Students' Achievement Goals, Emotion Perception Ability and Affect and Performance in the Classroom: A Multilevel Examination

    ERIC Educational Resources Information Center

    Vassiou, Aikaterini; Mouratidis, Athanasios; Andreou, Eleni; Kafetsios, Konstantinos

    2016-01-01

    Performance at school is affected not only by students' achievement goals but also by emotional exchanges among classmates and their teacher. In this study, we investigated relationships between students' achievement goals and emotion perception ability and class affect and performance. Participants were 949 Greek adolescent students in 49 classes…

  17. 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…

  18. Performing Multivariate Group Comparisons Following a Statistically Significant MANOVA.

    ERIC Educational Resources Information Center

    Enders, Craig K.

    2003-01-01

    This article illustrates 2 follow-up procedures that can be used to examine multivariate analysis of variance (MANOVA) group differences: the univariate analysis of a linear composite variable and multivariate contrasts. A heuristic data set is used to demonstrate the procedures, and it is shown that the follow-up methods will not always yield…

  19. Individual versus Group Argumentation: Student's Performance in a Malaysian Context

    ERIC Educational Resources Information Center

    Heng, Lee Ling; Surif, Johari; Seng, Cher Hau

    2014-01-01

    Scientific argumentation has been greatly emphasized in the National Science Standard due to its ability to enhance students' understanding of scientific concepts. This study investigated the mastery level of scientific argumentation, based on Toulmin's Argumentation Model (TAP), when students engage in individual and group argumentations. A total…

  20. Influence of Group Formation Choices on Academic Performance

    ERIC Educational Resources Information Center

    Seethamraju, Ravi; Borman, Mark

    2009-01-01

    With its multidisciplinary and applied foci, team-working skills are seen as especially critical in business courses in general and in business information systems courses in particular, and are specifically incorporated into desired graduate attributes by many universities. Past research has focused on the benefits of group working but little…

  1. The Role of Focus Groups with Other Performance Measurement Methods.

    ERIC Educational Resources Information Center

    Hart, Elizabeth

    Huddersfield University Library (England) has undertaken a wide range of evaluative studies of its services and systems, using various data collection techniques such as: user surveys; exit interviews; online and CD-ROM analysis; benchmarking; user groups; staffing and staff development evaluation; suggestion sheets; student project work; group…

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

    PubMed

    Donkoh, A

    1989-12-01

    An experiment was conducted to elucidate the influence of four constant ambient temperatures (20 degrees, 25 degrees, 30 degrees and 35 degrees 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 degrees, 25 degrees, 30 degrees and 35 degrees C treatments showed highly significant (P less than 0.0001) depression in growth rate, food intake and efficiency of food utilization, and a significant increase in water consumption for the 30 degrees and 35 degrees 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 degrees and 35 degrees 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. 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.

  4. 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…

  5. 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…

  6. Water consumption, not expectancies about water consumption, affects cognitive performance in adults.

    PubMed

    Edmonds, Caroline J; Crombie, Rosanna; Ballieux, Haiko; Gardner, Mark R; Dawkins, Lynne

    2013-01-01

    Research has shown that water supplementation positively affects cognitive performance in children and adults. The present study considered whether this could be a result of expectancies that individuals have about the effects of water on cognition. Forty-seven participants were recruited and told the study was examining the effects of repeated testing on cognitive performance. They were assigned either to a condition in which positive expectancies about the effects of drinking water were induced, or a control condition in which no expectancies were induced. Within these groups, approximately half were given a drink of water, while the remainder were not. Performance on a thirst scale, letter cancellation, digit span forwards and backwards and a simple reaction time task was assessed at baseline (before the drink) and 20 min and 40 min after water consumption. Effects of water, but not expectancy, were found on subjective thirst ratings and letter cancellation task performance, but not on digit span or reaction time. This suggests that water consumption effects on letter cancellation are due to the physiological effects of water, rather than expectancies about the effects of drinking water. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Bonding Performance of a Multimode Adhesive to Artificially-induced Caries-affected Primary Dentin.

    PubMed

    Lenzi, Tathiane Larissa; Raggio, Daniela Prócida; Soares, Fabio Zovico Maxnuck; Rocha, Rachel de Oliveira

    2015-04-01

    To investigate the bonding of a new universal adhesive applied using different etching strategies on sound and caries-affected dentin of primary teeth. Flat dentin surfaces from 50 primary molars were randomly assigned to 10 groups according to substrate (sound dentin [SD] vs caries-affected dentin [CAD] pH cycled for 14 days) and bonding approach (Scotchbond Universal Adhesive: self-etching, vs dry or wet-bonding etch-and-rinse strategies; Adper Single Bond Plus [two-step etch-and-rinse adhesive] and Clearfil SE Bond [two-step self-etching system] as controls). After 24 h of water storage, bonded sticks with cross-sectional areas of 0.8 mm2 were tested for microtensile bond strength (μTBS). Two sticks from each tooth were immersed in silver nitrate solution in order to evaluate nanoleakage (NL) with SEM. The μTBS means were analyzed using two-way ANOVA and Tukey's tests. For NL, the Kruskal-Wallis and Mann-Whitney tests were used (α = 0.05). The influence of the etching strategy on the bonding performance of the universal adhesive was substrate dependent. The self-etching approach resulted in lower μTBS values and higher silver nitrate uptake into hybrid layers for Scotchbond Universal Adhesive on SD, while no difference among experimental groups was observed in CAD. It is preferable to use the universal adhesive following either a dry- or wet-bonding etch-and-rinse approach on both sound and caries-affected primary dentin.

  8. Personality interacts with implicit affect to predict performance in analytic versus holistic processing.

    PubMed

    Kazén, Miguel; Kuhl, Julius; Quirin, Markus

    2015-06-01

    Both theoretical approaches and empirical evidence suggest that negative affect fosters analytic processing, whereas positive affect fosters holistic processing, but these effects are inconsistent. We aim to show that (a) differences in affect regulation abilities ("action orientation") and (b) implicit more so than self-reported affect assessment need to be considered to advance our understanding of these processes. Forty participants were asked to verify whether a word was correctly or incorrectly spelled to measure analytic processing, as well as to intuitively assess whether sets of three words were coherent (remote associates task) to measure holistic processing. As expected, implicit but not explicit negative affect interacted with low action orientation ("state orientation") to predict higher d' performance in word spelling, whereas implicit but not explicit positive affect interacted with high action orientation to predict higher d' performance in coherence judgments for word triads. Results are interpreted according to personality systems interaction theory. These findings suggest that affect and affect changes should be measured explicitly and implicitly to investigate affect-cognition interactions. Moreover, they suggest that good affect regulators benefit from positive affect for holistic processing, whereas bad affect regulators benefit from negative affect for analytical processing. © 2014 Wiley Periodicals, Inc.

  9. Comparative Study of Aerobic Performance Between Football and Judo Groups in Prepubertal Boys

    PubMed Central

    Triki, Moez; Rebai, Haithem; Shamssain, Mohammed; Masmoudi, Kaouthar; Fellmann, Nicole; Zouari, Hela; Zouari, Nouri; Tabka, Zouhair

    2013-01-01

    Purpose The aim of this study was to compare the impact of the practice of football and judo on lung function and aerobic performance of prepubertal boys. Methods A total of ninety six prepubertal boys were studied. They assessed a measure of body composition using the skin folds method. They performed lung plethysmography at rest, followed by an incremental exercise test. Results There was no significant difference in baseline spirometry between all groups (P>0.05). The maximal oxygen uptake [VO2max] and the VO2 at the ventilatory threshold [VT] were similar between all groups (P>0.05). The maximal minute ventilation [VEmax] of judokas was significantly higher than footballers (P<0.01) and similar at the [VT]. The Heart rate [HR] at [VT] of footballers and judokas was similar and significantly higher than control group (P<0.01). VO2max was significantly related to LM and negatively associated with FM. At the [VT] there was a significant relationship between P[VT] and LM and mainly with VE to VO2 [VT], P[VT] and HR[VT] in all groups. Conclusion Training in football and judo does not affect lung volumes and capacities, VO2max and VO2 at the [VT]. PMID:24427474

  10. 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.

  11. Ethnic differences in seasonal affective disorder and associated factors among five immigrant groups in Norway.

    PubMed

    Saheer, T B; Lien, Lars; Hauff, Edvard; Nirmal Kumar, Bernadette

    2013-10-01

    Research studies on seasonal affective disorder (SAD) among immigrant populations are scarce. The objective of this article was to explore the associated risk and protective factors on prevalence of winter SAD (W-SAD), sub syndromal SAD (S-SAD) and Summer-SAD among five immigrant groups living in Oslo, Norway. The Oslo Immigrants Health study (innvandrer HUBRO, 2002), is a large cross sectional epidemiological survey conducted among five of the largest immigrant groups living in Oslo. 1047 subjects were included in the analysis out of 3019 who participated in the survey. Mailed questionnaire which included selected items of the seasonal pattern assessment questionnaire (SPAQ), Hopkins symptom check list (HSCL) and other variables were used in the analysis. The lowest levels of W-SAD were found among Sri Lankan men and women and the highest among Iranians. W-SAD was significantly associated with country of birth, younger age, smoking, presence of mental distress, frequent visits to general practitioner or psychiatrist, self reported poor health and presence of chronic disorders. S-SAD was significantly associated with country of birth, smoking and higher levels of alcohol consumption. SPAQ was not culturally validated. Poor response rate (39.7%) can also be considered as a limitation. Ethnic differences in W-SAD and S-SAD were observed. Sri Lankans had the lowest levels of W-SAD. However, there is a need for culturally validated instruments and further research must focus on exploring protective factors for SAD. © 2013 Elsevier B.V. All rights reserved.

  12. Culture and Work-Groups. 1: Effect on Information Presentation on Group Performance

    DTIC Science & Technology

    2007-11-02

    and as such ought to realize nis „eeds, and goa,s of the (i„)group; ,b) socia , no™ an, du.y defined by the g.oup ^ ,Ka„ measure Seeking; (e) „efiefs...Wiley & Sons, Ltd. Johnston, W. (1991). Global work force 2000: The new world labor market . Harvard Business Review. March-April 115 - 127. WorkGroups...geometric shapes or a combination of numerals and shapes or numerals and colors. Regardless of the media ’used to convey this information about the city

  13. Performance Assessment Register. Working Group 12 Preliminary Report

    DTIC Science & Technology

    1988-08-01

    reported to the member nations and the NATO Authorities through the AGARD series of publications of which this is one. Participation in AGARD activities ...stressors; its activities , however, may also be of interest to those who wish to assess individual differences in information-processing capabilities...sent a simple questionnaire to researchers in his own country wiio are active in performance testing. The responses have been collated in the form of

  14. 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.

  15. 40 CFR Table 3 to Subpart U of... - Group 1 Storage Vessels at Existing Affected Sources

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Affected Sources 3 Table 3 to Subpart U of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION... Affected Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 75 ≤ capacity pressure of total organic HAP at storage temperature. ...

  16. The Relationship of Group Cohesion to Group Performance: A Research Integration Attempt

    DTIC Science & Technology

    1988-07-01

    display the data. The median effect size (product-moment correlation coefficient ) for the data. The median effect size (product-moment correlation ... coefficient ) for the 14 codable studies was .36, and the unweighted mean r was .42. When study effect sizes were weighted by the number of groups involved, the

  17. Nurses' views of factors affecting sleep for hospitalized children and their families: A focus group study.

    PubMed

    Stremler, Robyn; Adams, Sherri; Dryden-Palmer, Karen

    2015-08-01

    Light, noise, and interruptions from hospital staff lead to frequent awakenings and detrimental changes to sleep quantity and quality for children who are hospitalized and their parents who stay with them overnight. An understanding of nurses' views on how care affects sleep for the hospitalized child and parent is crucial to the development of strategies to decrease sleep disturbance in hospital. The purpose of this descriptive qualitative study was to gain an understanding of nurses' views on their role in and influence on sleep for families; perceived barriers and facilitators of patient and parent sleep at night; strategies nurses use to preserve sleep; the distribution, between parent and nurse, of care for the child at night; views of the parent as a recipient of nursing care at night; and the nature of interactions between nurses and families at night. Thirty registered nurses from general pediatric and critical care units participated in one of four semi-structured focus groups. Four main influences on sleep were identified: child factors; environmental factors; nurse-parent interaction factors; and nursing care factors. Some of these restricted nurses' ability to optimize sleep, but many factors were amenable to intervention. Balancing strategies to preserve sleep with the provision of nursing assessment and intervention was challenging and complicated by the difficult nature of work outside of usual waking hours. Nurses highlighted the need for formal policy and mentoring related to provision of nursing care at night in pediatric settings.

  18. Does degree of handedness in a group of right-handed individuals affect language comprehension?

    PubMed

    Newman, Sharlene; Malaia, Evie; Seo, Roy

    2014-04-01

    The impact of handedness on language processing has been studied extensively and the results indicate that there is a relationship between the two variables; however, the nature of the relationship is not at all clear. In the current study we explored degree of handedness (DH) opposed to direction in a group of right-handed individuals. fMRI was used to explore the impact of DH on the sentence comprehension network. The results revealed that during sentence comprehension activation in regions linked to semantic memory (e.g., anterior temporal cortex) were modulated by DH. Also, unexpectedly the precuneus/posterior cingulate gyrus which has been linked to episodic memory was also affected by DH. These results extend those reported previously by showing that the neural architecture that supports sentence comprehension is modulated by DH. More specifically, together the results presented here support the hypothesis proposed by Townsend, Carrithers, and Bever (2001) that DH interacts with the language system and impacts the strategy used during sentence comprehension.

  19. Does degree of handedness in a group of right-handed individuals affect language comprehension?

    PubMed Central

    Newman, Sharlene; Malaia, Evie; Seo, Roy

    2014-01-01

    The impact of handedness on language processing has been studied extensively and the results indicate that there is a relationship between the two variables; however, the nature of the relationship is not at all clear. In the current study we explored degree of handedness (DH) opposed to direction in a group of right-handed individuals. fMRI was used to explore the impact of DH on the sentence comprehension network. The results revealed that during sentence comprehension activation in regions linked to semantic memory (e.g., anterior temporal cortex) were modulated by DH. Also, unexpectedly the precuneus/posterior cingulate gyrus which has been linked to episodic memory was also affected by DH. These results extend those reported previously by showing that the neural architecture that supports sentence comprehension is modulated by DH. More specifically, together the results presented here support the hypothesis proposed by Townsend et al. (2001) that DH interacts with the language system and impacts the strategy used during sentence comprehension. PMID:24607732

  20. Study of individual and group affective processes in the crew of a simulated mission to Mars: Positive affectivity as a valuable indicator of changes in the crew affectivity

    NASA Astrophysics Data System (ADS)

    Poláčková Šolcová, Iva; Lačev, Alek; Šolcová, Iva

    2014-07-01

    The success of a long-duration space mission depends on various technical demands as well as on the psychological (cognitive, affective, and motivational) adaptation of crewmembers and the quality of interactions within the crew. We examined the ways crewmembers of a 520-day simulated spaceflight to Mars (held in the Institute for Biomedical Problems, in Moscow) experienced and regulated their moods and emotions. Results show that crewmembers experienced predominantly positive emotions throughout their 520-day isolation and the changes in mood of the crewmembers were asynchronous and balanced. The study suggests that during the simulation, crewmembers experienced and regulated their emotions differently than they usually do in their everyday life. In isolation, crewmembers preferred to suppress and neutralize their negative emotions and express overtly only emotions with positive valence. Although the affective processes were almost invariable throughout the simulation, two periods of time when the level of positive emotions declined were identified. Regarding the findings, the paper suggests that changes in positive affectivity could be a more valuable indicator of human experience in demanding but professional environments than changes in negative affectivity. Finally, the paper discusses the phenomenology of emotions during a real space mission.

  1. How Do Groups Work? Age Differences in Performance and the Social Outcomes of Peer Collaboration

    ERIC Educational Resources Information Center

    Leman, Patrick J.

    2015-01-01

    Do children derive different benefits from group collaboration at different ages? In the present study, 183 children from two age groups (8.8 and 13.4 years) took part in a class quiz as members of a group, or individually. In some groups, cohesiveness was made salient by awarding prizes to the top performing groups. In other groups, prizes were…

  2. How Do Groups Work? Age Differences in Performance and the Social Outcomes of Peer Collaboration

    ERIC Educational Resources Information Center

    Leman, Patrick J.

    2015-01-01

    Do children derive different benefits from group collaboration at different ages? In the present study, 183 children from two age groups (8.8 and 13.4 years) took part in a class quiz as members of a group, or individually. In some groups, cohesiveness was made salient by awarding prizes to the top performing groups. In other groups, prizes were…

  3. 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

  4. Does medical students' clinical performance affect their actual performance during medical internship?

    PubMed

    Han, Eui-Ryoung; Chung, Eun-Kyung

    2016-02-01

    This study examines the relationship between the clinical performance of medical students and their performance as doctors during their internships. This retrospective study involved 63 applicants to a residency programme conducted at the Chonnam National University Hospital, South Korea, in November 2012. We compared the performance of the applicants during their internship with the clinical performance of the applicants during their fourth year of medical school. The performance of the applicants as interns was periodically evaluated by the faculty of each department, while the clinical performance of the applicants as fourth year medical students was assessed using the Clinical Performance Examination (CPX) and the Objective Structured Clinical Examination (OSCE). The performance of the applicants as interns was positively correlated with their clinical performance as fourth year medical students, as measured by CPX and OSCE. The performance of the applicants as interns was moderately correlated with the patient-physician interactions items addressing communication and interpersonal skills in the CPX. 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, so that they are able to become competent doctors. Copyright © Singapore Medical Association.

  5. Analysis of postural control and muscular performance in young and elderly women in different age groups

    PubMed Central

    Gomes, Matheus M.; Reis, Júlia G.; Carvalho, Regiane L.; Tanaka, Erika H.; Hyppolito, Miguel A.; Abreu, Daniela C. C.

    2015-01-01

    BACKGROUND: muscle strength and power are two factors affecting balance. The impact of muscle strength and power on postural control has not been fully explored among different age strata over sixty. OBJECTIVES: the aim of the present study was to assess the muscle strength and power of elderly women in different age groups and determine their correlation with postural control. METHOD: eighty women were divided into four groups: the young 18-30 age group (n=20); the 60-64 age group (n=20); the 65-69 age group (n=20); and the 70-74 age group (n=20). The participants underwent maximum strength (one repetition maximum or 1-RM) and muscle power tests to assess the knee extensor and flexor muscles at 40%, 70%, and 90% 1-RM intensity. The time required by participants to recover their balance after disturbing their base of support was also assessed. RESULTS: the elderly women in the 60-64, 65-69, and 70-74 age groups exhibited similar muscle strength, power, and postural control (p>0.05); however, these values were lower than those of the young group (p<0.05) as expected. There was a correlation between muscle strength and power and the postural control performance (p<0.05). CONCLUSION: despite the age difference, elderly women aged 60 to 74 years exhibited similar abilities to generate strength and power with their lower limbs, and this ability could be one factor that explains the similar postural control shown by these women. PMID:25651132

  6. [How does sleep deprivation during 24 hours on call duty affect the cognitive performance orthopaedic residents?].

    PubMed

    Albergo, J I; Fernández, M C; Zaifrani, L; Giunta, D H; Albergo, L

    2016-01-01

    Sleep deprivation is usually present in residents during their training program. The purpose of our study was to analyze the cognitive performance of a group of orthopaedic residents before and after 24 hours on call duty. We include orthopaedic residents and their cognitive functions were evaluated by the following tests: Continuous Performance Test (CPT 2), Digit Spam (Versión 5), 1 letter Fonologic Fluence y Pasat Test. All the tests were done after a sleeping period at home of at least 6 hours and after being on call (sleeping less than 3 hours). Nineteen residents were included in the study. The median age was 27 ± 1.89 and 15 were male. The mean hours of sleeping at home was 6.5 (range 6-8) and after on call duty was 1.5 (range 0.5-3). Statistical difference were found in CPT 2 test en terms of correct answers (p=0.007), omissions (p=0.004) and perseverations (p=0.036). No significant differences were found in the other tests. Sleep deprivation after 24 hours on call duty affects cognitive performance of orthopaedic residents, increasing the number of errors and omissions. Copyright © 2015 SECOT. Published by Elsevier Espana. All rights reserved.

  7. 40 CFR Table 5 to Subpart Jjj of... - Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics 5 Table 5 to Subpart JJJ of Part 63 Protection of Environment... Storage Vessels at New Affected Sources Producing the Listed Thermoplastics Thermoplastic Chemical a...

  8. 40 CFR Table 3 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Affected Sources Producing the Listed Thermoplastics 3 Table 3 to Subpart JJJ of Part 63 Protection of... 63—Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics Thermoplastic Chemical a Vessel capacity (cubic meters) Vapor pressure b (kilopascals) ASA/AMSAN c styrene...

  9. 40 CFR Table 3 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Affected Sources Producing the Listed Thermoplastics 3 Table 3 to Subpart JJJ of Part 63 Protection of... 63—Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics Thermoplastic Chemical a Vessel capacity (cubic meters) Vapor pressure b (kilopascals) ASA/AMSAN c styrene...

  10. 40 CFR Table 3 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Affected Sources Producing the Listed Thermoplastics 3 Table 3 to Subpart JJJ of Part 63 Protection of... 63—Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics Thermoplastic Chemical a Vessel capacity (cubic meters) Vapor pressure b (kilopascals) ASA/AMSAN c styrene...

  11. A Learning Style-Based Grouping Collaborative Learning Approach to Improve EFL Students' Performance in English Courses

    ERIC Educational Resources Information Center

    Kuo, Yu-Chen; Chu, Hui-Chun; Huang, Chi-Hao

    2015-01-01

    Learning English is an important and challenging task for English as Foreign Language (EFL) students. Educators had indicated that, without proper learning support, most EFL students might feel frustrated while learning English, which could significantly affect their learning performance. In the past research, learning usually utilized grouping,…

  12. A Learning Style-Based Grouping Collaborative Learning Approach to Improve EFL Students' Performance in English Courses

    ERIC Educational Resources Information Center

    Kuo, Yu-Chen; Chu, Hui-Chun; Huang, Chi-Hao

    2015-01-01

    Learning English is an important and challenging task for English as Foreign Language (EFL) students. Educators had indicated that, without proper learning support, most EFL students might feel frustrated while learning English, which could significantly affect their learning performance. In the past research, learning usually utilized grouping,…

  13. High-performance functional Renormalization Group calculations for interacting fermions

    NASA Astrophysics Data System (ADS)

    Lichtenstein, J.; Sánchez de la Peña, D.; Rohe, D.; Di Napoli, E.; Honerkamp, C.; Maier, S. A.

    2017-04-01

    We derive a novel computational scheme for functional Renormalization Group (fRG) calculations for interacting fermions on 2D lattices. The scheme is based on the exchange parametrization fRG for the two-fermion interaction, with additional insertions of truncated partitions of unity. These insertions decouple the fermionic propagators from the exchange propagators and lead to a separation of the underlying equations. We demonstrate that this separation is numerically advantageous and may pave the way for refined, large-scale computational investigations even in the case of complex multiband systems. Furthermore, on the basis of speedup data gained from our implementation, it is shown that this new variant facilitates efficient calculations on a large number of multi-core CPUs. We apply the scheme to the t ,t‧ Hubbard model on a square lattice to analyze the convergence of the results with the bond length of the truncation of the partition of unity. In most parameter areas, a fast convergence can be observed. Finally, we compare to previous results in order to relate our approach to other fRG studies.

  14. Does physician leadership affect hospital quality, operational efficiency, and financial performance?

    PubMed

    Tasi, Michael C; Keswani, Aakash; Bozic, Kevin J

    2017-07-11

    With payers and policymakers' focus on improving the value (health outcomes achieved per health care dollar spent) of health care delivery, physicians are increasingly taking on senior leadership/management positions in health care organizations (Carsen & Xia, 2006). Little research has been done to understand the impact of physician leadership on the delivery of care. The aim of this study was to examine whether hospital systems led by physicians were associated with better U.S. News and World Report (USNWR) quality ratings, financial performance, and operating efficiency as compared with those led by nonphysician managers. Cross-sectional analysis of nationally representative data from Medicare Cost Reports and the USNWR on the 115 largest U.S. hospitals was performed. Bivariate analysis of physician-led and non-physician-led hospital networks included three categories: USNWR quality ratings, hospital volume, and financial performance. Multivariate analysis of hospital leadership, percent operating margin, inpatient days per hospital bed, and average quality rating was subsequently performed. Hospitals in physician-led hospital systems had higher quality ratings across all specialties and more inpatient days per hospital bed than did non-physician-led hospitals; however, there were no differences in the total revenue or profit margins between the groups. Physician leadership was independently associated with higher average quality ratings and inpatient days per bed. Large hospital systems led by physicians in 2015 received higher USNWR ratings and bed usage rates than did hospitals led by nonphysicians, with no differences in financial performance. This study suggests that physician leaders may possess skills, qualities, or management approaches that positively affect hospital quality and the value of care delivered. Hospital quality and efficiency ratings vary significantly and can impact consumer decisions. Hospital systems may benefit from the presence of

  15. Performance metric development for a group state estimator in airborne UHF GMTI applications

    NASA Astrophysics Data System (ADS)

    Elwell, Ryan A.

    2013-05-01

    This paper describes the development and implementation of evaluation metrics for group state estimator (GSE, i.e. group tracking) algorithms. Key differences between group tracker metrics and individual tracker metrics are the method used for track-to-truth association and the characterization of group raid size. Another significant contribution of this work is the incorporation of measured radar performance in assessing tracker performance. The result of this work is a set of measures of performance derived from canonical individual target tracker metrics, extended to characterize the additional information provided by a group tracker. The paper discusses additional considerations in group tracker evaluation, including the definition of a group and group-to-group confusion. Metrics are computed on real field data to provide examples of real-world analysis, demonstrating an approach which provides characterization of group tracker performance, independent of the sensor's performance.

  16. Space Allowance of the Littered Area Affects Lying Behavior in Group-Housed Horses

    PubMed Central

    Burla, Joan-Bryce; Rufener, Christina; Bachmann, Iris; Gygax, Lorenz; Patt, Antonia; Hillmann, Edna

    2017-01-01

    Horses can sleep while standing; however, recumbency is required for rapid eye movement (REM) sleep and therefore essential. Previous research indicated a minimal duration of recumbency of 30 min per 24 h to perform a minimal duration of REM sleep. For group-housed horses, suitable lying area represents a potentially limited resource. In Switzerland, minimal dimensions for the space allowance of the littered area are therefore legally required. To assess the effect of different space allowances of the littered area on lying behavior, 38 horses in 8 groups were exposed to 4 treatments for 11 days each; T0: no litter provided, T0.5: 0.5× minimal dimensions, T1: minimal dimensions, and T1.5: 1.5× minimal dimensions. Non-littered areas were covered with hard rubber mats. Lying behavior was observed during the last 72 h of each treatment. The total number of lying bouts per 24 h was similar in treatments providing litter, whereas in treatment T0, recumbency occurred only rarely (F1,93 = 14.74, p = 0.0002) with the majority of horses lying down for less than 30 min per 24 h (χ12=11.82, p = 0.0006). Overall, the total duration of recumbency per 24 h increased with increasing dimensions of the littered area, whereby the effect attenuated between treatment T1 and T1.5 in high-ranking horses but continued in low-ranking horses (F1,91 = 3.22, p = 0.076). Furthermore, low-ranking horses showed considerably more forcedly terminated lying bouts in treatments T0.5 and T1, but were similar to high-ranking horses in T1.5 (F1,76 = 8.43, p = 0.005). Nonetheless, a number of individuals showed durations of recumbency of less than 30 min per 24 h even in treatment T1.5. The lying behavior was dependent on the availability of a soft and deformable surface for recumbency. A beneficial effect of enlarged dimensions of the littered area was shown by increased durations of recumbency and decreased proportion of forcedly terminated lying

  17. Space Allowance of the Littered Area Affects Lying Behavior in Group-Housed Horses.

    PubMed

    Burla, Joan-Bryce; Rufener, Christina; Bachmann, Iris; Gygax, Lorenz; Patt, Antonia; Hillmann, Edna

    2017-01-01

    Horses can sleep while standing; however, recumbency is required for rapid eye movement (REM) sleep and therefore essential. Previous research indicated a minimal duration of recumbency of 30 min per 24 h to perform a minimal duration of REM sleep. For group-housed horses, suitable lying area represents a potentially limited resource. In Switzerland, minimal dimensions for the space allowance of the littered area are therefore legally required. To assess the effect of different space allowances of the littered area on lying behavior, 38 horses in 8 groups were exposed to 4 treatments for 11 days each; T0: no litter provided, T0.5: 0.5× minimal dimensions, T1: minimal dimensions, and T1.5: 1.5× minimal dimensions. Non-littered areas were covered with hard rubber mats. Lying behavior was observed during the last 72 h of each treatment. The total number of lying bouts per 24 h was similar in treatments providing litter, whereas in treatment T0, recumbency occurred only rarely (F1,93 = 14.74, p = 0.0002) with the majority of horses lying down for less than 30 min per 24 h ([Formula: see text], p = 0.0006). Overall, the total duration of recumbency per 24 h increased with increasing dimensions of the littered area, whereby the effect attenuated between treatment T1 and T1.5 in high-ranking horses but continued in low-ranking horses (F1,91 = 3.22, p = 0.076). Furthermore, low-ranking horses showed considerably more forcedly terminated lying bouts in treatments T0.5 and T1, but were similar to high-ranking horses in T1.5 (F1,76 = 8.43, p = 0.005). Nonetheless, a number of individuals showed durations of recumbency of less than 30 min per 24 h even in treatment T1.5. The lying behavior was dependent on the availability of a soft and deformable surface for recumbency. A beneficial effect of enlarged dimensions of the littered area was shown by increased durations of recumbency and decreased proportion of forcedly terminated

  18. Happy Places, Horrible Times, and Scary Learners: Affective Performances and Sticky Objects in Inclusive Classrooms

    ERIC Educational Resources Information Center

    Naraian, Srikala; Khoja-Moolji, Shenila

    2016-01-01

    Drawing on data from two studies conducted in US public schools, this paper traces the affective productions and performances of teachers to illustrate the role of affect in delineating (non)normative pedagogical practices in inclusive classrooms. Occupying a borderland space in narrative inquiry that permitted the straddling of differing…

  19. 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…

  20. Maternal Affection Moderates the Impact of Psychological Control on a Child's Mathematical Performance

    ERIC Educational Resources Information Center

    Aunola, Kaisa; Nurmi, Jari-Erik

    2004-01-01

    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…

  1. 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…

  2. 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…

  3. 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 (c) 2016 APA, all rights reserved).

  4. Happy Places, Horrible Times, and Scary Learners: Affective Performances and Sticky Objects in Inclusive Classrooms

    ERIC Educational Resources Information Center

    Naraian, Srikala; Khoja-Moolji, Shenila

    2016-01-01

    Drawing on data from two studies conducted in US public schools, this paper traces the affective productions and performances of teachers to illustrate the role of affect in delineating (non)normative pedagogical practices in inclusive classrooms. Occupying a borderland space in narrative inquiry that permitted the straddling of differing…

  5. 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…

  6. 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…

  7. Relationships between Climate, Process, and Performance in Continuous Quality Improvement Groups

    ERIC Educational Resources Information Center

    Wilkens, Roxanne; London, Manuel

    2006-01-01

    This study examined relationships between group climate (participants' learning orientation, feelings of psychological safety, and self-disclosure), process (feedback and conflict), and performance in continuous quality improvement groups. Forty-nine participants in eight hospital groups were surveyed as the groups neared completion. Groups were…

  8. Relationships between Climate, Process, and Performance in Continuous Quality Improvement Groups

    ERIC Educational Resources Information Center

    Wilkens, Roxanne; London, Manuel

    2006-01-01

    This study examined relationships between group climate (participants' learning orientation, feelings of psychological safety, and self-disclosure), process (feedback and conflict), and performance in continuous quality improvement groups. Forty-nine participants in eight hospital groups were surveyed as the groups neared completion. Groups were…

  9. Delay in taking the American Board of Surgery qualifying examination affects examination performance.

    PubMed

    Malangoni, Mark A; Jones, Andrew T; Rubright, Jonathan; Biester, Thomas W; Buyske, Jo; Lewis, Frank R

    2012-10-01

    The American Board of Surgery (ABS) Qualifying Examination (QE) represents an important step along the pathway to board certification. We investigated whether candidates who delayed taking the QE had worse performance on the examination. QE pass rates and equated scaled scores for all first-time examinees from 2006 to 2010 (n = 5,193) were reviewed. After eliminating examinees who could not be matched to final ABS In-Training Examination (ABSITE) scores, the remaining cohort (n = 4,909) was analyzed by comparing those who took the exam immediately after residency (Immediate, n = 4,488) to those who delayed for 1 or more years (Delay, n = 421). The Immediate group had a mean first-time QE pass rate of 87% compared to 57% for those who delayed 1 year and 48% for those who delayed 2 or more years (P < .001). Regression analysis demonstrated that delay in taking the QE remained a significant determinant of exam failure after controlling for ABSITE scores (odds ratio = 0.35; 95% CI, 0.29-0.43; P = .001). Undergraduate medical education and postresidency training did not affect the results. The Delay group had lower equated scaled scores, a greater ultimate failure rate on the QE, and was more likely to fail the ABS Certifying Examination on the first attempt. These results demonstrate that candidates who delayed taking the QE immediately are at extremely high risk for exam failure and failure to achieve board certification. These findings presumably are due to deterioration of knowledge over time, but they also may represent characteristics of the Delay group that are currently undefined. Copyright © 2012 Mosby, Inc. All rights reserved.

  10. Fluid forces enhance the performance of an aspirant leader in self-organized living groups.

    PubMed

    De Rosis, Alessandro

    2014-01-01

    In this paper, the performance of an individual aiming at guiding a self-organized group is numerically investigated. A collective behavioural model is adopted, accounting for the mutual repulsion, attraction and orientation experienced by the individuals. Moreover, these represent a set of solid particles which are supposed to be immersed in a fictitious viscous fluid. In particular, the lattice Boltzmann and Immersed boundary methods are used to predict the fluid dynamics, whereas the effect of the hydrodynamic forces on particles is accounted for by solving the equation of the solid motion through the time discontinuous Galerkin scheme. Numerical simulations are carried out by involving the individuals in a dichotomous process. On the one hand, an aspirant leader (AL) additional individual is added to the system. AL is forced to move along a prescribed direction which intersects the group. On the other hand, these tend to depart from an obstacle represented by a rotating lamina which is placed in the fluid domain. A numerical campaign is carried out by varying the fluid viscosity and, as a consequence, the hydrodynamic field. Moreover, scenarios characterized by different values of the size of the group are investigated. In order to estimate the AL's performance, a proper parameter is introduced, depending on the number of individuals following AL. Present findings show that the sole collective behavioural equations are insufficient to predict the AL's performance, since the motion is drastically affected by the presence of the surrounding fluid. With respect to the existing literature, the proposed numerical model is enriched by accounting for the presence of the encompassing fluid, thus computing the hydrodynamic forces arising when the individuals move.

  11. Fluid Forces Enhance the Performance of an Aspirant Leader in Self-Organized Living Groups

    PubMed Central

    De Rosis, Alessandro

    2014-01-01

    In this paper, the performance of an individual aiming at guiding a self-organized group is numerically investigated. A collective behavioural model is adopted, accounting for the mutual repulsion, attraction and orientation experienced by the individuals. Moreover, these represent a set of solid particles which are supposed to be immersed in a fictitious viscous fluid. In particular, the lattice Boltzmann and Immersed boundary methods are used to predict the fluid dynamics, whereas the effect of the hydrodynamic forces on particles is accounted for by solving the equation of the solid motion through the time discontinuous Galerkin scheme. Numerical simulations are carried out by involving the individuals in a dichotomous process. On the one hand, an aspirant leader (AL) additional individual is added to the system. AL is forced to move along a prescribed direction which intersects the group. On the other hand, these tend to depart from an obstacle represented by a rotating lamina which is placed in the fluid domain. A numerical campaign is carried out by varying the fluid viscosity and, as a consequence, the hydrodynamic field. Moreover, scenarios characterized by different values of the size of the group are investigated. In order to estimate the AL's performance, a proper parameter is introduced, depending on the number of individuals following AL. Present findings show that the sole collective behavioural equations are insufficient to predict the AL's performance, since the motion is drastically affected by the presence of the surrounding fluid. With respect to the existing literature, the proposed numerical model is enriched by accounting for the presence of the encompassing fluid, thus computing the hydrodynamic forces arising when the individuals move. PMID:25501965

  12. The influence of pentafluorophenyl groups on the nonlinear optical (NLO) performance of high generation dendrons and dendrimers

    PubMed Central

    Wu, Wenbo; Wang, Can; Li, Qianqian; Ye, Cheng; Qin, Jingui; Li, Zhen

    2014-01-01

    With the aim to make the influence of pentafluorophenyl groups in the periphery of high generation dendrons and dendrimers on their NLO performance clearly, some NLO dendrons and dendrimers with different chromophore moieties or different end-capped groups were carefully designed and investigated in detail. The results demonstrated that some strong Ar-ArF interactions between the pentafluorophenyl groups in the periphery and the normal phenyl rings of the donors, could influence the topological structures of dendrons or dendrimers, and then affect their NLO performance. Furthermore, the optical transparency and the stability of the dendrons and dendrimers with pentafluorophenyl groups as end-capped moieties were all improved, in comparison with normal dendrons and dendrimers containing phenyl ones as the end-capped groups. PMID:25168867

  13. The influence of pentafluorophenyl groups on the nonlinear optical (NLO) performance of high generation dendrons and dendrimers.

    PubMed

    Wu, Wenbo; Wang, Can; Li, Qianqian; Ye, Cheng; Qin, Jingui; Li, Zhen

    2014-08-29

    With the aim to make the influence of pentafluorophenyl groups in the periphery of high generation dendrons and dendrimers on their NLO performance clearly, some NLO dendrons and dendrimers with different chromophore moieties or different end-capped groups were carefully designed and investigated in detail. The results demonstrated that some strong Ar-Ar(F) interactions between the pentafluorophenyl groups in the periphery and the normal phenyl rings of the donors, could influence the topological structures of dendrons or dendrimers, and then affect their NLO performance. Furthermore, the optical transparency and the stability of the dendrons and dendrimers with pentafluorophenyl groups as end-capped moieties were all improved, in comparison with normal dendrons and dendrimers containing phenyl ones as the end-capped groups.

  14. 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…

  15. 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…

  16. 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…

  17. Affective Cues and Processing Strategy: Color-Coded Examination Forms Influence Performance.

    ERIC Educational Resources Information Center

    Sinclair, Robert C.; Soldat, Alexander S.; Mark, Melvin M.

    1998-01-01

    Argues that external cues provide affective information that influence processing strategy and, therefore, examination performance. Notes the differences in performance for two midterm examinations, identical, except that they were printed on blue and red paper. Discusses a method for appropriately adjusting scores to control for form effects.…

  18. How Need for Cognition Affects the Formation of Performance Expectancies at School

    ERIC Educational Resources Information Center

    Dickhauser, Oliver; Reinhard, Marc-Andre

    2009-01-01

    Individuals with low Need for Cognition (NFC) have been found to process information using a peripheral route compared to individuals higher in NFC. These differences affect the formation of performance expectancies. Based on previous work demonstrating that the formation of performance expectancies can be understood as an information processing…

  19. 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…

  20. Using Representations in Geometry: A Model of Students' Cognitive and Affective Performance

    ERIC Educational Resources Information Center

    Panaoura, Areti

    2014-01-01

    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…

  1. 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…

  2. 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…

  3. A self organizing map approach to physiological data analysis for enhanced group performance.

    SciTech Connect

    Doser, Adele Beatrice; Merkle, Peter Benedict

    2004-10-01

    A Self Organizing Map (SOM) approach was used to analyze physiological data taken from a group of subjects participating in a cooperative video shooting game. The ultimate aim was to discover signatures of group cooperation, conflict, leadership, and performance. Such information could be fed back to participants in a meaningful way, and ultimately increase group performance in national security applications, where the consequences of a poor group decision can be devastating. Results demonstrated that a SOM can be a useful tool in revealing individual and group signatures from physiological data, and could ultimately be used to heighten group performance.

  4. 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. (c) 2015 APA, all rights reserved).

  5. Importance of Having Low-Density Functional Groups for Generating High-Performance Semiconducting Polymer Dots

    PubMed Central

    Zhang, Xuanjun; Yu, Jiangbo; Wu, Changfeng; Jin, Yuhui; Rong, Yu; Ye, Fangmao

    2012-01-01

    Semiconducting polymers with low-density side-chain carboxylic acid groups were synthesized to form stable, functionalized, and highly fluorescent polymer dots (Pdots). The influence of the molar fraction of hydrophilic side-chains on Pdot properties and performance was systematically investigated. Our results show that the density of side-chain carboxylic acid groups significantly affects Pdot stability, internal structure, fluorescence brightness, and nonspecific binding in cellular labeling. Fluorescence spectroscopy, single-particle imaging, and a dye-doping method were employed to investigate the fluorescence brightness and the internal structure of the Pdots. The results of these experiments indicate that semiconducting polymers with low density of side-chain functional groups can form stable, compact, and highly bright Pdots as compared to those with high density of hydrophilic side-chains. The functionalized polymer dots were conjugated to streptavidin (SA) by carbodiimide-catalyzed coupling and the Pdot-SA probes effectively and specifically labeled the cancer cell-surface marker Her2 in human breast cancer cells. The carboxylate-functionalized polymer could also be covalently modified with small functional molecules to generate Pdot probes for click chemistry-based bioorthogonal labeling. This study presents a promising approach for further developing functional Pdot probes for biological applications. PMID:22607220

  6. An Empirical Examination of Factors Affecting Group Effectiveness in Information Systems Projects

    ERIC Educational Resources Information Center

    Hasan, Bassam; Ali, Jafar

    2007-01-01

    Although group project concepts and skills have become a major component in most information systems (IS) academic programs, very little research has attempted to examine factors that may improve or undermine effectiveness of IS group projects. Accordingly, based on relevant literatures, this study develops and empirically tests a model of factors…

  7. A flexible influence of affective feelings on creative and analytic performance.

    PubMed

    Huntsinger, Jeffrey R; Ray, Cara

    2016-09-01

    Considerable research shows that positive affect improves performance on creative tasks and negative affect improves performance on analytic tasks. The present research entertained the idea that affective feelings have flexible, rather than fixed, effects on cognitive performance. Consistent with the idea that positive and negative affect signal the value of accessible processing inclinations, the influence of affective feelings on performance on analytic or creative tasks was found to be flexibly responsive to the relative accessibility of different styles of processing (i.e., heuristic vs. systematic, global vs. local). When a global processing orientation was accessible happy participants generated more creative uses for a brick (Experiment 1), successfully solved more remote associates and insight problems (Experiment 2) and displayed broader categorization (Experiment 3) than those in sad moods. When a local processing orientation was accessible this pattern reversed. When a heuristic processing style was accessible happy participants were more likely to commit the conjunction fallacy (Experiment 3) and showed less pronounced anchoring effects (Experiment 4) than sad participants. When a systematic processing style was accessible this pattern reversed. Implications of these results for relevant affect-cognition models are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  8. The effect of goal setting on group performance: a meta-analysis.

    PubMed

    Kleingeld, Ad; van Mierlo, Heleen; Arends, Lidia

    2011-11-01

    Updating and extending the work of O'Leary-Kelly, Martocchio, and Frink (1994), with this meta-analysis on goal setting and group performance we show that specific difficult goals yield considerably higher group performance compared with nonspecific goals (d = 0.80 ± 0.35, k = 23 effect sizes). Moderately difficult and easy goals were also associated with performance benefits relative to nonspecific goals, but these effects were smaller. The overall effect size for all group goals was d = 0.56 ± 0.19 (k = 49). Unexpectedly, task interdependence, task complexity, and participation did not moderate the effect of group goals. Our inventory of multilevel goals in interdependent groups indicated that the effect of individual goals in groups on group performance was contingent upon the focus of the goal: "Egocentric" individual goals, aimed at maximizing individual performance, yielded a particularly negative group-performance effect (d = -1.75 ± 0.60, k = 6), whereas "groupcentric" goals, aimed at maximizing the individual contribution to the group's performance, showed a positive effect (d = 1.20 ± 1.03, k = 4). These findings demonstrate that group goals have a robust effect on group performance. Individual goals can also promote group performance but should be used with caution in interdependent groups. Future research might explore the role of multilevel goals for group performance in more detail. The striking lack of recent field studies in organizational settings that emerged from our brief review of trends in group goal-setting research should be taken into account when designing future studies in this domain.

  9. Microsatellite DNA Suggests that Group Size Affects Sex-biased Dispersal Patterns in Red Colobus Monkeys

    PubMed Central

    Miyamoto, Michael M.; Allen, Julie M.; Gogarten, Jan F.; Chapman, Colin A.

    2013-01-01

    Dispersal is a major life history trait of social organisms influencing the behavioral and genetic structure of their groups. Unfortunately, primate dispersal is difficult to quantify, because of the rarity of these events and our inability to ascertain if individuals dispersed or died when they disappear. Socioecological models have been partially developed to understand the ecological causes of different dispersal systems and their social consequences. However, these models have yielded confusing results when applied to folivores. The folivorous red colobus monkey (Procolobus rufomitratus) in Kibale National Park, Uganda is thought to exhibit female-biased dispersal, although both sexes have been observed to disperse and there remains considerable debate over the selective pressures favoring the transfers of males and females and the causes of variation in the proportion of each sex to leave the natal group. We circumvent this problem by using microsatellite DNA data to investigate the prediction that female dispersal will be more frequent in larger groups as compared to smaller ones. The rationale for this prediction is that red colobus exhibit increased within-group competition in bigger groups, which should favor higher female dispersal rates and ultimately lower female relatedness. Genetic data from two unequally sized neighboring groups of red colobus demonstrate increased female relatedness within the smaller group, suggesting females are less likely to disperse when there is less within-group competition. We suggest that the dispersal system is mediated to some degree by scramble competition and group size. Since red colobus group sizes have increased throughout Kibale by over 50% in the last decade, these changes may have major implications for the genetic structure and ultimately the population viability of this endangered primate. PMID:23307485

  10. Microsatellite DNA suggests that group size affects sex-biased dispersal patterns in red colobus monkeys.

    PubMed

    Miyamoto, Michael M; Allen, Julie M; Gogarten, Jan F; Chapman, Colin A

    2013-05-01

    Dispersal is a major life history trait of social organisms influencing the behavioral and genetic structure of their groups. Unfortunately, primate dispersal is difficult to quantify, because of the rarity of these events and our inability to ascertain if individuals dispersed or died when they disappear. Socioecological models have been partially developed to understand the ecological causes of different dispersal systems and their social consequences. However, these models have yielded confusing results when applied to folivores. The folivorous red colobus monkey (Procolobus rufomitratus) in Kibale National Park, Uganda is thought to exhibit female-biased dispersal, although both sexes have been observed to disperse and there remains considerable debate over the selective pressures favoring the transfers of males and females and the causes of variation in the proportion of each sex to leave the natal group. We circumvent this problem by using microsatellite DNA data to investigate the prediction that female dispersal will be more frequent in larger groups as compared to smaller ones. The rationale for this prediction is that red colobus exhibit increased within-group competition in bigger groups, which should favor higher female dispersal rates and ultimately lower female relatedness. Genetic data from two unequally sized neighboring groups of red colobus demonstrate increased female relatedness within the smaller group, suggesting females are less likely to disperse when there is less within-group competition. We suggest that the dispersal system is mediated to some degree by scramble competition and group size. Since red colobus group sizes have increased throughout Kibale by over 50% in the last decade, these changes may have major implications for the genetic structure and ultimately the population viability of this endangered primate.

  11. An examination of the relationship between strategic group membership and hospital performance.

    PubMed

    Marlin, Dan; Huonker, John W; Sun, Minghe

    2002-01-01

    Membership in a particular strategic group, where a strategic group can be defined as groups of firms in an industry following similar competitive approaches and having similar market positions, defines the essentials of a firm's strategy. This study longitudinally examines the relationship between strategic group membership and performance in the hospital industry.

  12. Social group size affects Mycobacterium bovis infection in European badgers (Meles meles).

    PubMed

    Woodroffe, Rosie; Donnelly, Christl A; Wei, Gao; Cox, D R; Bourne, F John; Burke, Terry; Butlin, Roger K; Cheeseman, C L; Gettinby, George; Gilks, Peter; Hedges, Simon; Jenkins, Helen E; Johnston, W Thomas; McInerney, John P; Morrison, W Ivan; Pope, Lisa C

    2009-07-01

    1. In most social animals, the prevalence of directly transmitted pathogens increases in larger groups and at higher population densities. Such patterns are predicted by models of Mycobacterium bovis infection in European badgers (Meles meles). 2. We investigated the relationship between badger abundance and M. bovis prevalence, using data on 2696 adult badgers in 10 populations sampled at the start of the Randomized Badger Culling Trial. 3. M. bovis prevalence was consistently higher at low badger densities and in small social groups. M. bovis prevalence was also higher among badgers whose genetic profiles suggested that they had immigrated into their assigned social groups. 4. The association between high M. bovis prevalence and small badger group size appeared not to have been caused by previous small-scale culling in study areas, which had been suspended, on average, 5 years before the start of the current study. 5. The observed pattern of prevalence might occur through badgers in smaller groups interacting more frequently with members of neighbouring groups; detailed behavioural data are needed to test this hypothesis. Likewise, longitudinal data are needed to determine whether the size of infected groups might be suppressed by disease-related mortality. 6. Although M. bovis prevalence was lower at high population densities, the absolute number of infected badgers was higher. However, this does not necessarily mean that the risk of M. bovis transmission to cattle is highest at high badger densities, since transmission risk depends on badger behaviour as well as on badger density.

  13. Joint Attention Initiation with and without Positive Affect: Risk Group Differences and Associations with ASD Symptoms

    ERIC Educational Resources Information Center

    Gangi, Devon N.; Ibañez, Lisa V.; Messinger, Daniel S.

    2014-01-01

    Infants at risk for autism spectrum disorders (ASD) may have difficulty integrating smiles into initiating joint attention (IJA) bids. A specific IJA pattern, anticipatory smiling, may communicate preexisting positive affect when an infant smiles at an object and then turns the smile toward the social partner. We compared the development of…

  14. 40 CFR Table 2 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... at Existing Affected Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 75≤capacity 151 ≥13.1 151≤capacity ≥5.2 a Maximum true vapor pressure of total organic HAP at storage temperature....

  15. 40 CFR Table 2 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... at Existing Affected Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 75≤capacity 151 ≥13.1 151≤capacity ≥5.2 a Maximum true vapor pressure of total organic HAP at storage temperature....

  16. 40 CFR Table 2 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Existing Affected Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 75≤capacity 151 ≥13.1 151≤capacity ≥5.2 a Maximum true vapor pressure of total organic HAP at storage temperature....

  17. 40 CFR Table 2 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Existing Affected Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 75≤capacity 151 ≥13.1 151≤capacity ≥5.2 a Maximum true vapor pressure of total organic HAP at storage temperature....

  18. Factors Affecting the Management of Women Groups' Micro and Small Enterprises in Kakamega District, Kenya

    ERIC Educational Resources Information Center

    Wawire, Nelson H. W.; Nafukho, Fredrick M.

    2010-01-01

    Purpose: The purpose of this study is to highlight the main factors that affect the management of the WGs' Micro and Small Enterprises (MSEs) in Kakamega District and Africa in general. Design/methodology/approach: The study adopted a descriptive research design. This is because the study was concerned about a univariate question in which the…

  19. Ecological and Dynamical Study of the Creative Process and Affects of Scientific Students Working in Groups

    ERIC Educational Resources Information Center

    Peilloux, Aurélien; Botella, Marion

    2016-01-01

    Although creativity has drawn the attention of researchers during the past century, collaborative processes have barely been investigated. In this article, the collective dimension of a creative process is investigated, based on a dynamic and ecological approach that includes an affective component. "Dynamic" means that the creative…

  20. Joint Attention Initiation with and without Positive Affect: Risk Group Differences and Associations with ASD Symptoms

    ERIC Educational Resources Information Center

    Gangi, Devon N.; Ibañez, Lisa V.; Messinger, Daniel S.

    2014-01-01

    Infants at risk for autism spectrum disorders (ASD) may have difficulty integrating smiles into initiating joint attention (IJA) bids. A specific IJA pattern, anticipatory smiling, may communicate preexisting positive affect when an infant smiles at an object and then turns the smile toward the social partner. We compared the development of…

  1. How Does Polytomous Item Bias Affect Total-Group Survey Score Comparisons?

    ERIC Educational Resources Information Center

    Hidalgo, Ma Dolores; Benítez, Isabel; Padilla, Jose-Luis; Gómez-Benito, Juana

    2017-01-01

    The growing use of scales in survey questionnaires warrants the need to address how does polytomous differential item functioning (DIF) affect observed scale score comparisons. The aim of this study is to investigate the impact of DIF on the type I error and effect size of the independent samples t-test on the observed total scale scores. A…

  2. Causal attribution and affective response as mediated by task performance and self-acceptance.

    PubMed

    Green, T D; Bailey, R C; Zinser, O; Williams, D E

    1994-12-01

    Predictions derived from cognitive consistency theories, self-esteem theories, and ego-serving-bias theory concerning how students would make attributional and affective responses to their academic performance were investigated. 202 university students completed a measure of self-acceptance of their college ability and made attributional and affective responses to an hypothetical examination performance. Analyses showed that students receiving positive feedback perceived greater internal causality and responded with greater positive affect than students receiving negative feedback. Self-acceptance did not moderate the attributions or affective reactions. The results supported the ego-serving-bias theory and provided partial support for self-esteem theory. Findings did not support predictions from cognitive-consistency theory.

  3. 40 CFR Table 2 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers....1 151≤capacity ≥5.2 a Maximum true vapor pressure of total organic HAP at storage temperature....

  4. 40 CFR Table 4 to Subpart Jjj of... - Group 1 Storage Vessels at New Affected Sources

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins Pt... ≤ capacity ≥0.7 a Maximum true vapor pressure of total organic HAP at storage temperature....

  5. Bridging faultlines by valuing diversity: diversity beliefs, information elaboration, and performance in diverse work groups.

    PubMed

    Homan, Astrid C; van Knippenberg, Daan; Van Kleef, Gerben A; De Dreu, Carsten K W

    2007-09-01

    Although there are numerous potential benefits to diversity in work groups, converging dimensions of diversity often prevent groups from exploiting this potential. In a study of heterogeneous decision-making groups, the authors examined whether the disruptive effects of diversity faultlines can be overcome by convincing groups of the value of diversity. Groups were persuaded either of the value of diversity or the value of similarity for group performance, and they were provided with either homogeneous or heterogeneous information. As expected, informationally diverse groups performed better when they held pro-diversity rather than pro-similarity beliefs, whereas the performance of informationally homogeneous groups was unaffected by diversity beliefs. This effect was mediated by group-level information elaboration. Implications for diversity management in organizations are discussed. (c) 2007 APA.

  6. How do groups work? Age differences in performance and the social outcomes of peer collaboration.

    PubMed

    Leman, Patrick J

    2015-05-01

    Do children derive different benefits from group collaboration at different ages? In the present study, 183 children from two age groups (8.8 and 13.4 years) took part in a class quiz as members of a group, or individually. In some groups, cohesiveness was made salient by awarding prizes to the top performing groups. In other groups, prizes were awarded to the best performing individuals. Findings, both in terms of social outcomes and performance in the quiz, indicated that the 8-year olds viewed the benefits of group membership in terms of the opportunities to receive information from other members. The 13-year olds, in contrast, viewed group collaboration as a constructive process where success was connected with group cohesiveness. © 2014 Cognitive Science Society, Inc.

  7. Group music performance causes elevated pain thresholds and social bonding in small and large groups of singers.

    PubMed

    Weinstein, Daniel; Launay, Jacques; Pearce, Eiluned; Dunbar, Robin I M; Stewart, Lauren

    2016-03-01

    Over our evolutionary history, humans have faced the problem of how to create and maintain social bonds in progressively larger groups compared to those of our primate ancestors. Evidence from historical and anthropological records suggests that group music-making might act as a mechanism by which this large-scale social bonding could occur. While previous research has shown effects of music making on social bonds in small group contexts, the question of whether this effect 'scales up' to larger groups is particularly important when considering the potential role of music for large-scale social bonding. The current study recruited individuals from a community choir that met in both small (n = 20 - 80) and large (a 'megachoir' combining individuals from the smaller subchoirs n = 232) group contexts. Participants gave self-report measures (via a survey) of social bonding and had pain threshold measurements taken (as a proxy for endorphin release) before and after 90 minutes of singing. Results showed that feelings of inclusion, connectivity, positive affect, and measures of endorphin release all increased across singing rehearsals and that the influence of group singing was comparable for pain thresholds in the large versus small group context. Levels of social closeness were found to be greater at pre- and post-levels for the small choir condition. However, the large choir condition experienced a greater change in social closeness as compared to the small condition. The finding that singing together fosters social closeness - even in large contexts where individuals are not known to each other - is consistent with evolutionary accounts that emphasize the role of music in social bonding, particularly in the context of creating larger cohesive groups than other primates are able to manage.

  8. Performance of methods for estimating the effect of covariates on group membership probabilities in group-based trajectory models.

    PubMed

    Davies, Christopher E; Giles, Lynne C; Glonek, Gary Fv

    2017-01-01

    One purpose of a longitudinal study is to gain insight of how characteristics at earlier points in time can impact on subsequent outcomes. Typically, the outcome variable varies over time and the data for each individual can be used to form a discrete path of measurements, that is a trajectory. Group-based trajectory modelling methods seek to identify subgroups of individuals within a population with trajectories that are more similar to each other than to trajectories in distinct groups. An approach to modelling the influence of covariates measured at earlier time points in the group-based setting is to consider models wherein these covariates affect the group membership probabilities. Models in which prior covariates impact the trajectories directly are also possible but are not considered here. In the present study, we compared six different methods for estimating the effect of covariates on the group membership probabilities, which have different approaches to account for the uncertainty in the group membership assignment. We found that when investigating the effect of one or several covariates on a group-based trajectory model, the full likelihood approach minimized the bias in the estimate of the covariate effect. In this '1-step' approach, the estimation of the effect of covariates and the trajectory model are carried out simultaneously. Of the '3-step' approaches, where the effect of the covariates is assessed subsequent to the estimation of the group-based trajectory model, only Vermunt's improved 3 step resulted in bias estimates similar in size to the full likelihood approach. The remaining methods considered resulted in considerably higher bias in the covariate effect estimates and should not be used. In addition to the bias empirically demonstrated for the probability regression approach, we have shown analytically that it is biased in general.

  9. Does Group Prenatal Care Affect Satisfaction And Prenatal Care Utilization in Iranian Pregnant Women?

    PubMed Central

    Jafari, F; Eftekhar, H; Mohammad, K; Fotouhi, A

    2010-01-01

    Background: The need to provide high quality prenatal care services, which take account of women’s views and specifically address their need for information, support and communication, has been advocated and group prenatal care, had been suggested as one of the ways to achieve this objective. The purpose of this study was to examine the impact of group versus individual prenatal care on satisfaction and prenatal care use. Methods: This was a cluster-randomized controlled trial with the health center as the randomization unit that conducted in 2007. Satisfaction was measured through a standardized questionnaire, and the Kotelchuck Adequacy of Prenatal Care Utilization Index was used to measure prenatal care utilization. Results: We recruited 678 women (group prenatal care, (N= 344) and individual prenatal care, (N=334) in the study. Women in group prenatal care model were more satisfied than women in individual prenatal care model in all areas evaluated, including information, communication, co-ordination and quality of care. Group care women were significantly more likely to have adequate prenatal care than individual care women were (OR=1.35 95% CI=1.26–1.44). Conclusions: Group prenatal care was associated with a significant improvement in client satisfaction and prenatal care utilization. This model of care has implications for the planning and provision of prenatal services within public health system, which is moving toward a better quality health care, and increasing use of services. PMID:23113007

  10. The experience of self-care groups with people affected by leprosy: ALERT, Ethiopia.

    PubMed

    Benbow, C; Tamiru, T

    2001-09-01

    This paper describes the development of self-care groups in Ethiopia by ALERT, and the successes and failures experienced in the process. The groups were started in 1995 in response to two main problems, the increasing number of people dependent on ALERT to heal their wounds despite years of health education, and the limited financial resources of ALERT for wound healing supplies. By December 1999, there were a total of 72 established groups. Group membership was voluntary. There have been a number of positive outcomes. Group members have taken up responsibility for managing and monitoring their own wounds and supplying their own wound healing materials. More attention is paid to their personal hygiene and personal appearance. They also report increased confidence to participate in society, restored dignity and self-respect, and a sense of belonging within the community. In addition, some members have started to pay more attention to their local environmental hygiene by building pit latrines and waste disposal sites. The ALERT staff involved in this initiative had to change their role from that of a leprosy service provider to a self-care group facilitator, but not all were successful in making this transition. The remaining challenge for the programme is sustainability and further development through the National Tuberculosis and Leprosy Control Programme, The Ethiopian National Association for Ex-Leprosy Patients and possibly other organizations too.

  11. 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.

  12. Forming a support group for people affected by inflammatory bowel disease

    PubMed Central

    Swarup, Nidhi; Nayak, Saumya; Lee, Jessie; Pai Raikar, Srinivas; Hou, David; Sockalingam, Senthil; Lee, Ken J

    2017-01-01

    Inflammatory bowel disease (IBD) – primarily Crohn’s disease and ulcerative colitis – is a debilitating lifelong condition with significant health and economic costs. From diagnosis to management, IBD can cause huge psychosocial concerns to patients and their caregivers. This study reports an experience of a Crohn’s patient, leading to the formation of the first IBD patient support group in Singapore and how this group has evolved in the last 4 years in supporting other IBD patients. IBD patient advocacy and/or support groups facilitate open conversations on patients’ fears, concerns, preferences and needs, and may potentially improve disease knowledge and quality of life for individuals with the condition or their families. PMID:28255233

  13. How does social essentialism affect the development of inter-group relations?

    PubMed

    Rhodes, Marjorie; Leslie, Sarah-Jane; Saunders, Katya; Dunham, Yarrow; Cimpian, Andrei

    2017-02-22

    Psychological essentialism is a pervasive conceptual bias to view categories as reflecting something deep, stable, and informative about their members. Scholars from diverse disciplines have long theorized that psychological essentialism has negative ramifications for inter-group relations, yet little previous empirical work has experimentally tested the social implications of essentialist beliefs. Three studies (N = 127, ages 4.5-6) found that experimentally inducing essentialist beliefs about a novel social category led children to share fewer resources with category members, but did not lead to the out-group dislike that defines social prejudice. These findings indicate that essentialism negatively influences some key components of inter-group relations, but does not lead directly to the development of prejudice.

  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. Building Emotion and Affect Regulation (BEAR): Preliminary Evidence from an Open Trial in Children's Residential Group Homes in Singapore

    ERIC Educational Resources Information Center

    Pat-Horenczyk, R.; Shi, C. Sim Wei; Schramm-Yavin, S.; Bar-Halpern, M.; Tan, L. J.

    2015-01-01

    Background: The Building Emotion and Affect Regulation (BEAR) program is a theory-based group intervention for enhancing resilience in children, with a focus on strengthening emotion regulation. The BEAR is a 6-session protocol for children aged 7-12 who have been subject to traumatic life events. Objective: This paper presents the guiding…

  16. 40 CFR Table 3 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics 3 Table 3 to Subpart JJJ of Part 63 Protection of... Thermoplastics Thermoplastic Chemical a Vessel capacity (cubic meters) Vapor pressure b (kilopascals) ASA/AMSAN c...

  17. 40 CFR Table 3 to Subpart Jjj of... - Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Group 1 Storage Vessels at Existing Affected Sources Producing the Listed Thermoplastics 3 Table 3 to Subpart JJJ of Part 63 Protection of... Thermoplastics Thermoplastic Chemical a Vessel capacity (cubic meters) Vapor pressure b (kilopascals) ASA/AMSAN c...

  18. Building Emotion and Affect Regulation (BEAR): Preliminary Evidence from an Open Trial in Children's Residential Group Homes in Singapore

    ERIC Educational Resources Information Center

    Pat-Horenczyk, R.; Shi, C. Sim Wei; Schramm-Yavin, S.; Bar-Halpern, M.; Tan, L. J.

    2015-01-01

    Background: The Building Emotion and Affect Regulation (BEAR) program is a theory-based group intervention for enhancing resilience in children, with a focus on strengthening emotion regulation. The BEAR is a 6-session protocol for children aged 7-12 who have been subject to traumatic life events. Objective: This paper presents the guiding…

  19. 40 CFR Table 5 to Subpart Jjj of... - Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics 5 Table 5 to Subpart JJJ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR...

  20. 40 CFR Table 5 to Subpart Jjj of... - Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics 5 Table 5 to Subpart JJJ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR...

  1. 40 CFR Table 5 to Subpart Jjj of... - Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics 5 Table 5 to Subpart JJJ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR...

  2. 40 CFR Table 5 to Subpart Jjj of... - Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics 5 Table 5 to Subpart JJJ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR...

  3. A biosocial-affect model of adolescent sensation seeking: the role of affect evaluation and peer-group influence in adolescent drug use.

    PubMed

    Romer, Daniel; Hennessy, Michael

    2007-06-01

    Adolescence is a period of heightened experimentation with risky behavior. Models of brain development suggest that this phenomenon is partly the result of increased adolescent sensation seeking unaccompanied by maturation in ability to evaluate risks. We test an alternative biosocial-affect model in which favorable affect attached to behavior leads to discounting of risks. Although the model applies to both adolescents and adults, it predicts that the surge in sensation seeking during adolescence increases affective attraction to risky behavior, reduces perceived risk of the behavior, and results in peer-group reinforcement of these effects. We estimated models that included these influences for three drugs (tobacco, alcohol, and marijuana) in a national sample of youth ages 14 to 22. Consistent with brain maturation models, sensation seeking rose during the age period under study with girls peaking earlier than boys. Nevertheless, independent of age or gender, the biosocial-affect model explained the relation between sensation seeking and drug use. The findings indicate that although adolescents recognize the risks of drug use, they are subject to both biological and social influences that encourage risk taking. Implications for the prevention of risky adolescent behavior are discussed.

  4. Paying for positive group esteem: how inequity frames affect whites' responses to redistributive policies.

    PubMed

    Lowery, Brian S; Chow, Rosalind M; Knowles, Eric D; Unzueta, Miguel M

    2012-02-01

    This article finds that, when faced with racial inequity framed as White advantage, Whites' desire to think well of their racial group increases their support for policies perceived to harm Whites. Across 4 studies, the article provides evidence that (a) relative to minority disadvantage, White advantage increases Whites' support for policies perceived to reduce their group's economic opportunities, but does not increase support for policies perceived to increase minority opportunities; and (b) the effect of White advantage on Whites' esteem for their ingroup drives the effect of inequity frame on support for policies perceived to reduce Whites' opportunities.

  5. Tail autotomy affects bipedalism but not sprint performance in a cursorial Mediterranean lizard.

    PubMed

    Savvides, Pantelis; Stavrou, Maria; Pafilis, Panayiotis; Sfenthourakis, Spyros

    2017-02-01

    Running is essential in all terrestrial animals mainly for finding food and mates and escaping from predators. Lizards employ running in all their everyday functions, among which defense stands out. Besides flight, tail autotomy is another very common antipredatory strategy within most lizard families. The impact of tail loss to sprint performance seems to be species dependent. In some lizard species, tail shedding reduces sprint speed, in other species, increases it, and, in a few species, speed is not affected at all. Here, we aimed to clarify the effect of tail autotomy on the sprint performance of a cursorial lizard with particular adaptations for running, such as bipedalism and spike-like protruding scales (fringes) on the toepads that allow high speed on sandy substrates. We hypothesized that individuals that performed bipedalism, and have more and larger fringes, would achieve higher sprint performance. We also anticipated that tail shedding would affect sprint speed (though we were not able to define in what way because of the unpredictable effects that tail loss has on different species). According to our results, individuals that ran bipedally were faster; limb length and fringe size had limited effects on sprint performance whereas tail autotomy affected quadrupedal running only in females. Nonetheless, tail loss significantly affected bipedalism: the ability for running on hindlimbs was completely lost in all adult individuals and in 72.3% of juveniles.

  6. Tail autotomy affects bipedalism but not sprint performance in a cursorial Mediterranean lizard

    NASA Astrophysics Data System (ADS)

    Savvides, Pantelis; Stavrou, Maria; Pafilis, Panayiotis; Sfenthourakis, Spyros

    2017-02-01

    Running is essential in all terrestrial animals mainly for finding food and mates and escaping from predators. Lizards employ running in all their everyday functions, among which defense stands out. Besides flight, tail autotomy is another very common antipredatory strategy within most lizard families. The impact of tail loss to sprint performance seems to be species dependent. In some lizard species, tail shedding reduces sprint speed, in other species, increases it, and, in a few species, speed is not affected at all. Here, we aimed to clarify the effect of tail autotomy on the sprint performance of a cursorial lizard with particular adaptations for running, such as bipedalism and spike-like protruding scales (fringes) on the toepads that allow high speed on sandy substrates. We hypothesized that individuals that performed bipedalism, and have more and larger fringes, would achieve higher sprint performance. We also anticipated that tail shedding would affect sprint speed (though we were not able to define in what way because of the unpredictable effects that tail loss has on different species). According to our results, individuals that ran bipedally were faster; limb length and fringe size had limited effects on sprint performance whereas tail autotomy affected quadrupedal running only in females. Nonetheless, tail loss significantly affected bipedalism: the ability for running on hindlimbs was completely lost in all adult individuals and in 72.3% of juveniles.

  7. Loving-kindness in the treatment of traumatized refugees and minority groups: a typology of mindfulness and the nodal network model of affect and affect regulation.

    PubMed

    Hinton, Devon E; Ojserkis, Rebecca A; Jalal, Baland; Peou, Sonith; Hofmann, Stefan G

    2013-08-01

    This article discusses how loving-kindness can be used to treat traumatized refugees and minority groups, focusing on examples from our treatment, culturally adapted cognitive-behavioral therapy (CA-CBT). To show how we integrate loving-kindness with other mindfulness interventions and why loving-kindness should be an effective therapeutic technique, we present a typology of mindfulness states and the Nodal Network Model (NNM) of Affect and Affect Regulation. We argue that mindfulness techniques such as loving-kindness are therapeutic for refugees and minority populations because of their potential for increasing emotional flexibility, decreasing rumination, serving as emotional regulation techniques, and forming part of a new adaptive processing mode centered on psychological flexibility. We present a case to illustrate the clinical use of loving-kindness within the context of CA-CBT.

  8. Factors Affecting Ethnic Minority Students' Attainment in Secondary Schools in Cyprus: A Focus Group Study

    ERIC Educational Resources Information Center

    Theodosiou-Zipiti, Galatia; West, Mel; Muijs, Daniel

    2010-01-01

    This is the first study in Cyprus aiming to gain insight into the factors responsible for the low attainment of ethnic minority students observed in earlier studies. Teachers from different schools and cities on the island participated in a focus group discussion. Identified factors related to the child, parents, home environment, teachers,…

  9. Does Family Group Decision Making Affect Child Welfare Outcomes? Findings from a Randomized Control Study

    ERIC Educational Resources Information Center

    Berzin, Stephanie Cosner; Cohen, Ed; Thomas, Karen; Dawson, William C.

    2008-01-01

    This article describes the evaluation of two family group decision-making programs administered under the California Title IV-E Waiver Demonstration Project. This is the only evaluation using random assignment to examine FGDM. Overall, results did not indicate more positive outcomes for children receiving the intervention, but did indicate that…

  10. How group factors affect adolescent change talk and substance use outcomes: implications for motivational interviewing training.

    PubMed

    Osilla, Karen Chan; Ortiz, J Alexis; Miles, Jeremy N V; Pedersen, Eric R; Houck, Jon M; D'Amico, Elizabeth J

    2015-01-01

    Clients who verbalize statements arguing for change (change talk [CT]) in psychotherapy are more likely to decrease alcohol and other drug use (AOD) compared with clients who voice statements in opposition of change (sustain talk [ST]). Little is known about how CT and ST are expressed in groups in which adolescents may vary in their AOD use severity and readiness to change. First, we examined how session content was associated with CT/ST, and then we looked at whether different subtypes of CT/ST were associated with subsequent AOD outcomes 3 months later. Audio recordings (N = 129 sessions) of a 6-session group motivational interviewing (MI) intervention, Free Talk, were coded. Session content was not associated with CT; however, some session content was associated with higher percentages of ST (e.g., normative feedback). Subtypes of CT (Commitment and Reason) were associated with improved AOD outcomes, whereas Ability subtype remarks were related to increased marijuana use, intentions, and consequences. Findings offer helpful guidance for clinical training and narrow in on the type of CT to try to elicit in Group MI sessions. Regardless of session content, adolescents can benefit from hearing CT during the group. PsycINFO Database Record (c) 2015 APA, all rights reserved.

  11. Factors affecting temporal and spatial soil moisture variation in and adjacent to group selection openings

    Treesearch

    W.H. McNab

    1991-01-01

    Soil moisture content was intensively sampled in three, 1-acre blocks containing an opening and surrounding mature upland hardwoods. Openings covering 0.19-0.26 ac were created by group-selection cutting, and they were occupied by 1-year-old trees and shrubs.

  12. Using Focus Groups to Identify Factors Affecting Healthful Weight Maintenance in Latino Immigrants

    ERIC Educational Resources Information Center

    Greaney, Mary L.; Lees, Faith D.; Lynch, Breanna; Sebelia, Linda; Greene, Geoffrey W.

    2012-01-01

    Objective: To explore (1) how migration influenced physical activity and dietary behaviors among Latino immigrants and (2) participants' perception of concepts related to a Health at Every Size (HAES) approach to weight maintenance (mindful eating, taking care of oneself). Methods: Four focus groups (n = 35), homogenous by sex, were conducted in…

  13. Factors Affecting the Adequacy and Preferability of Semiparametric Groups-Based Approximations of Continuous Growth Trajectories

    ERIC Educational Resources Information Center

    Sterba, Sonya K.; Baldasaro, Ruth E.; Bauer, Daniel J.

    2012-01-01

    Psychologists have long been interested in characterizing individual differences in change over time. It is often plausible to assume that the distribution of these individual differences is continuous in nature, yet theory is seldom so specific as to designate its parametric form (e.g., normal). Semiparametric groups-based trajectory models…

  14. 40 CFR Table 3 to Subpart U of... - Group 1 Storage Vessels at Existing Affected Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ≤capacity ≥5.2 a Maximum true vapor pressure of total organic HAP at storage temperature. ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers...

  15. Understanding Process and Affective Factors in Small Group versus Individual Learning with Technology

    ERIC Educational Resources Information Center

    Lou, Yiping

    2004-01-01

    Based on 198 independent findings from 71 studies with experimental or statistical controls, the results of this meta-analysis indicate that, on average, students learning with computers in small groups attempted a greater amount of task (d + = +0.15), used more learning strategies (d + = +0.36), had more positive attitude toward small group…

  16. How Flexible Grouping Affects the Collaborative Patterns in a Mobile-Assisted Chinese Character Learning Game?

    ERIC Educational Resources Information Center

    Wong, Lung-Hsiang; Hsu, Ching-Kun; Sun, Jizhen; Boticki, Ivica

    2013-01-01

    This paper reports the impacts of spontaneous student grouping to develop young students' orthographic awareness in the process of learning Chinese characters. A mobile-assisted Chinese character forming game is used to assign each student a Chinese character component on their smartphones through a wireless network. Fifteen Singaporean students,…

  17. Using Focus Groups to Identify Factors Affecting Healthful Weight Maintenance in Latino Immigrants

    ERIC Educational Resources Information Center

    Greaney, Mary L.; Lees, Faith D.; Lynch, Breanna; Sebelia, Linda; Greene, Geoffrey W.

    2012-01-01

    Objective: To explore (1) how migration influenced physical activity and dietary behaviors among Latino immigrants and (2) participants' perception of concepts related to a Health at Every Size (HAES) approach to weight maintenance (mindful eating, taking care of oneself). Methods: Four focus groups (n = 35), homogenous by sex, were conducted in…

  18. Factors Affecting the Turnover of Different Groups of Part-Time Workers

    ERIC Educational Resources Information Center

    Senter, Jenell L.; Martin, James E.

    2007-01-01

    Past research on employee attitudes and behavior has focused mainly on full-time employees. When part-time employees have been studied, the research has concentrated on the differences between full-time and part-time employees. Recent research has suggested that part-time employees should not be viewed as a single, undifferentiated group. Instead…

  19. How Group Experience Affects Outcomes from NOLS Programs: A Means-End Investigation

    ERIC Educational Resources Information Center

    Goldenberg, Marni; Soule, Katherine

    2011-01-01

    Using means-end theory, this study evaluates how being part of a group influences outcomes of National Outdoor Leadership School (NOLS) participants. This study examines outcomes from NOLS courses during the summer of 2006 in the Wind River Mountain Range of Wyoming. Immediately following 2006 course completion, a convenience sample of 345…

  20. How Group Experience Affects Outcomes from NOLS Programs: A Means-End Investigation

    ERIC Educational Resources Information Center

    Goldenberg, Marni; Soule, Katherine

    2011-01-01

    Using means-end theory, this study evaluates how being part of a group influences outcomes of National Outdoor Leadership School (NOLS) participants. This study examines outcomes from NOLS courses during the summer of 2006 in the Wind River Mountain Range of Wyoming. Immediately following 2006 course completion, a convenience sample of 345…

  1. Pitch structure, but not selective attention, affects accent weightings in metrical grouping.

    PubMed

    Prince, Jon B

    2014-10-01

    Among other cues, pitch and temporal accents contribute to grouping in musical sequences. However, exactly how they combine remains unclear, possibly because of the role of structural organization. In 3 experiments, participants rated the perceived metrical grouping of sequences that either adhered to the rules of tonal Western musical pitch structure (musical key) or did not (atonal). The tonal status of sequences did not provide any grouping cues and was irrelevant to the task. Experiment 1 established equally strong levels of pitch leap accents and duration accents in baseline conditions, which were then recombined in subsequent experiments. Neither accent type was stronger or weaker for tonal and atonal contexts. In Experiment 2, pitch leap accents dominated over duration accents, but the extent of this advantage was greater when sequences were tonal. Experiment 3 ruled out an attentional origin of this effect by replicating this finding while explicitly manipulating attention to pitch or duration accents between participant groups. Overall, the presence of tonal pitch structure made the dimension of pitch more salient at the expense of time. These findings support a dimensional salience framework in which the presence of organizational structure prioritizes the processing of the more structured dimension regardless of task relevance, independent from psychophysical difficulty, and impervious to attentional allocation.

  2. Contemplating the ultimate sacrifice: identity fusion channels pro-group affect, cognition, and moral decision making.

    PubMed

    Swann, William B; Gómez, Angel; Buhrmester, Michael D; López-Rodríguez, Lucía; Jiménez, Juan; Vázquez, Alexandra

    2014-05-01

    Although most people acknowledge the moral virtue in sacrificing oneself to save others, few actually endorse self-sacrifice. Seven experiments explored the cognitive and emotional mechanisms that underlie such endorsements. Participants responded to 1 of 2 moral dilemmas in which they could save 5 members of their country only by sacrificing themselves. Over 90% of participants acknowledged that the moral course of action was to sacrifice oneself to save others (Experiment 1), yet only those who were strongly fused with the group preferentially endorsed self-sacrifice (Experiments 2-7). The presence of a concern with saving group members rather than the absence of a concern with self-preservation motivated strongly fused participants to endorse sacrificing themselves for the group (Experiment 3). Analyses of think aloud protocols suggested that saving others was motivated by emotional engagement with the group among strongly fused participants but by utilitarian concerns among weakly fused participants (Experiment 4). Hurrying participants' responses increased self-sacrifice among strongly fused participants but decreased self-sacrifice among weakly fused participants (Experiment 5). Priming the personal self increased endorsement of self-sacrifice among strongly fused participants but further reduced endorsement of self-sacrifice among weakly fused participants (Experiment 6). Strongly fused participants ignored utilitarian considerations, but weakly fused persons endorsed self-sacrifice more when it would save more people (Experiment 7). Apparently, the emotional engagement with the group experienced by strongly fused persons overrides the desire for self-preservation and compels them to translate their moral beliefs into self-sacrificial behavior.

  3. Arbuscular mycorrhizal fungal phylogenetic groups differ in affecting host plants along heavy metal levels.

    PubMed

    He, Lei; Yang, Haishui; Yu, Zhenxing; Tang, Jianjun; Xu, Ligen; Chen, Xin

    2014-10-01

    Arbuscular mycorrhizal fungi (AMF) are important components of soil microbial communities, and play important role in plant growth. However, the effects of AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) on host plant under various heavy metal levels are not clear. Here we conducted a meta-analysis to compare symbiotic relationship between AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) and host plant functional groups (herbs vs. trees, and non-legumes vs. legumes) at three heavy metal levels. In the meta-analysis, we calculate the effect size (ln(RR)) by taking the natural logarithm of the response ratio of inoculated to non-inoculated shoot biomass from each study. We found that the effect size of Glomeraceae increased, but the effect size of non-Glomeraceae decreased under high level of heavy metal compared to low level. According to the effect size, both Glomeraceae and non-Glomeraceae promoted host plant growth, but had different effects under various heavy metal levels. Glomeraceae provided more benefit to host plants than non-Glomeraceae did under heavy metal condition, while non-Glomeraceae provided more benefit to host plants than Glomeraceae did under no heavy metal. AMF phylogenetic groups also differed in promoting plant functional groups under various heavy metal levels. Interacting with Glomeraceae, herbs and legumes grew better than trees and non-legumes did under high heavy metal level, while trees and legumes grew better than herbs and non-legumes did under medium heavy metal level. Interacting with non-Glomeraceae, herbs and legumes grew better than trees and non-legumes did under no heavy metal. We suggested that the combination of legume with Glomeraceae could be a useful way in the remediation of heavy metal polluted environment.

  4. 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.

  5. Collective Efficacy and Group Functioning: The Effect of Performance Feedback on Efficacy Assessments, Goal Setting, Task Persistence and Overall Performance

    DTIC Science & Technology

    2002-08-01

    This study examined the effect of collective efficacy on group functioning across a series of cognitive tasks. Specifically, this experiment used...performance feedback to manipulate efficacy levels in order to investigate the effect of efficacy on group goal setting, task persistence, and overall...performance. The effect of experimental manipulations and sequence were investigated at both the task specific (prediction for current task) and general

  6. Do group dynamics affect colour morph clines during a range shift?

    PubMed

    Lancaster, L T; Dudaniec, R Y; Hansson, B; Svensson, E I

    2017-04-01

    Species exhibiting colour polymorphism are thought to have an ecological advantage at the landscape scale, because spatial segregation of alternatively adapted ecotypes into diverse habitats can increase the species' niche breadth and thus confer greater geographic range size. However, morph frequencies are also influenced by intrapopulational processes such as frequency- or density-dependent social interactions. To identify how social feedback may affect clinal variation in morph frequencies, we investigated reciprocal interactions between morph-specific thermal tolerance, local climatic conditions and social environments, in the context of a colour-morph frequency cline associated with a recent range expansion in blue-tailed damselflies (Ischnura elegans) in Sweden. Cold tolerances of gynochromes (female-like female morph) were positively correlated with local gynochrome frequencies, suggesting a positive frequency-dependent fitness benefit. In contrast, androchrome (male-mimic female morph) cold tolerances were improved following recent exposure to cold weather, suggesting a beneficial environmental acclimation effect. Thus, according to an environment-matching hypothesis for clinal variation, androchrome frequencies should therefore increase towards the (cooler) range limit. In contrast to this prediction, gynochrome frequencies increased at the expanding range limit, consistent with a positive frequency-dependent social feedback that is beneficial when invading novel climates. Our results suggest that when phenotypes or fitnesses are affected by interactions with conspecifics, beneficial social effects on environmental tolerances may (i) facilitate range shifts, and (ii) reverse or counteract typical patterns of intraspecific interactions and environment-matching clines observed in stable populations observed over broader geographic scales.

  7. Age and group residence but not maternal dominance affect dominance rank in young domestic horses.

    PubMed

    Komárková, M; Bartošová, J; Dubcová, J

    2014-11-01

    We present a study focused on those factors influencing dominance position in young horses, with emphasis on the role of the mother. Horses, as other group-living polygynous mammals, form stable linear dominance hierarchies based on agonistic interactions. Higher dominance positions are believed to be connected, in both sexes, to better condition and higher reproductive success. Many variables play a role in forming the dominant-submissive relationships between horses; however, the maternal effect on the dominance position of the offspring still remains unclear, as do the possible mechanisms of transference ("inheritance"). We hypothesized that the maternal dominance position, plus differences in suckling parameters or maternal style, may be responsible for later outcome of the offspring's dominance position, characterized by 2 variables: index of fighting success (CB); and rate of winning encounters (RW). Our study animals were 8 groups of Kladruby horses, loose-housed lactating mares with foals (n = 66 mare-foal pairs); and subsequently 4 groups of the same foals at 3 yr of age. Our results revealed the impact of age on the dominance position of the young horses (P < 0.001 for CB, and P < 0.01 for RW), and residence in the group (P < 0.01, P < 0.01, respectively); not the maternal dominance position. Older foals reached higher dominance positions, independent of the dominance position, age, or experience of the mother; therefore, we did not find support for direct inheritance of maternal rank. Nevertheless, the foals born to the same mare in 2 consecutive seasons (n = 16 mares) revealed fair repeatability in the dominance position they obtained at 3 yr of age (intraclass correlation coefficient = 0.46). This suggests an important constant effect of the mother on the social success of her progeny; however, we did not find a significant effect of any of the tested variables describing maternal characteristics or maternal care. Dominance position depended

  8. 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.

  9. Team Satisfaction and Student Group Performance: A Cross-Cultural Study

    ERIC Educational Resources Information Center

    Zeitun, Rami M.; Abdulqader, Khalid Shams; Alshare, Khaled A.

    2013-01-01

    The authors examined the relationship between team satisfaction and students' performance in group projects in two universities, one from the United States and one from Qatar. The results showed that there is a significant positive correlation between team satisfaction and group performance only for the American students. Demographic factors such…

  10. The Effect of Goal Setting on Group Performance: A Meta-Analysis

    ERIC Educational Resources Information Center

    Kleingeld, Ad; van Mierlo, Heleen; Arends, Lidia

    2011-01-01

    Updating and extending the work of O'Leary-Kelly, Martocchio, and Frink (1994), with this meta-analysis on goal setting and group performance we show that specific difficult goals yield considerably higher group performance compared with nonspecific goals (d = 0.80 plus or minus 0.35, k = 23 effect sizes). Moderately difficult and easy goals were…

  11. Team Satisfaction and Student Group Performance: A Cross-Cultural Study

    ERIC Educational Resources Information Center

    Zeitun, Rami M.; Abdulqader, Khalid Shams; Alshare, Khaled A.

    2013-01-01

    The authors examined the relationship between team satisfaction and students' performance in group projects in two universities, one from the United States and one from Qatar. The results showed that there is a significant positive correlation between team satisfaction and group performance only for the American students. Demographic factors such…

  12. Victimization of high performers: the roles of envy and work group identification.

    PubMed

    Kim, Eugene; Glomb, Theresa M

    2014-07-01

    Drawing from victim precipitation, social comparison, and identity theories, this study develops and tests an integrative model of the victimization of high-performing employees. We examine envy as an explanatory mechanism of the victimization of high performers from fellow group members and propose work group identification as a moderator of this envy mechanism. Study 1, in a sample of 4,874 university staff employees in 339 work groups, supports the proposition that high performers are more likely to be targets of victimization. In Study 2, multisource data collected at 2 time points (217 employees in 67 work groups in 3 organizations), supports the proposition that high performers are more likely to be targets of victimization because of fellow group members' envy, and work group identification mitigates the mediated relationship.

  13. Variables affecting the propensity to buy branded beef among groups of Australian beef buyers.

    PubMed

    Morales, L Emilio; Griffith, Garry; Wright, Victor; Fleming, Euan; Umberger, Wendy; Hoang, Nam

    2013-06-01

    Australian beef consumers have different preferences given their characteristics and the effect on expected quality of cues related to health, production process and eating experience. Beef brands using Meat Standards Australia (MSA) grades can help to signal quality and reduce consumers' uncertainty when shopping. The objective of this study is to identify the characteristics of beef buyers and their perceptions about product attributes that affect the propensity to buy branded beef. Binary logistic models were applied identifying differences between all respondents and the potential target market, including buyers in medium to high income segments, and between buyers in the target market who would buy branded beef for taste and health reasons. Variables increasing the propensity to buy branded beef include previous experience, appreciation for branded cuts and concern about quality more than size. Finally, variations in preferences for marbling and cut were found between buyers who would buy branded beef for taste and health reasons. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. 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…

  15. 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...

  16. Motivating Factors that Affect Enrolment and Student Performance in an ODL Engineering Program

    ERIC Educational Resources Information Center

    Dadigamuwa, P. R.; Senanayake, Samans

    2012-01-01

    The present study was carried out to determine the motivating factors for enrolling in an engineering study programme in open and distance learning (ODL) and the factors that affect the students' performance. The study was conducted with two convenient samples of students following distance learning courses in engineering technology, conducted by…

  17. 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…

  18. 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…

  19. 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…

  20. 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...

  1. 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…

  2. 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…

  3. Academic Procrastination and the Performance of Graduate-Level Cooperative Groups in Research Methods Courses

    ERIC Educational Resources Information Center

    Jiao, Qun G.; DaRos-Voseles, Denise A.; Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.

    2011-01-01

    This study examined the extent to which academic procrastination predicted the performance of cooperative groups in graduate-level research methods courses. A total of 28 groups was examined (n = 83 students), ranging in size from 2 to 5 (M = 2.96, SD = 1.10). Multiple regression analyses revealed that neither within-group mean nor within-group…

  4. Short Circuits or Superconductors? Effects of Group Composition on High-Achieving Students' Science Assessment Performance.

    ERIC Educational Resources Information Center

    Webb, Noreen M.; Nemer, Kariane Mari; Zuniga, Stephen

    2002-01-01

    Studied the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high-ability students completing science assessments. Results for 83 high ability students show the quality of group functioning serves as the strongest predictor of high-ability students' performance and explained much of the…

  5. 40 CFR 63.845 - Incorporation of new source performance standards for potroom groups.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... potroom group after the replacements; and (G) A discussion of any economic or technical limitations the... performance standards for potroom groups. 63.845 Section 63.845 Protection of Environment ENVIRONMENTAL... groups. (a) Applicability. The provisions in paragraphs (a) through (i) of this section shall apply to...

  6. 40 CFR 63.845 - Incorporation of new source performance standards for potroom groups.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... potroom group after the replacements; and (G) A discussion of any economic or technical limitations the... performance standards for potroom groups. 63.845 Section 63.845 Protection of Environment ENVIRONMENTAL... groups. (a) Applicability. The provisions in paragraphs (a) through (i) of this section shall apply to...

  7. 40 CFR 63.845 - Incorporation of new source performance standards for potroom groups.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... potroom group after the replacements; and (G) A discussion of any economic or technical limitations the... performance standards for potroom groups. 63.845 Section 63.845 Protection of Environment ENVIRONMENTAL... groups. (a) Applicability. The provisions in paragraphs (a) through (i) of this section shall apply to...

  8. Short Circuits or Superconductors? Effects of Group Composition on High-Achieving Students' Science Assessment Performance.

    ERIC Educational Resources Information Center

    Webb, Noreen M.; Nemer, Kariane Mari; Zuniga, Stephen

    2002-01-01

    Studied the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high-ability students completing science assessments. Results for 83 high ability students show the quality of group functioning serves as the strongest predictor of high-ability students' performance and explained much of the…

  9. Comparison of Group Cohesion, Class Participation, and Exam Performance in Live and Online Classes

    ERIC Educational Resources Information Center

    Galyon, Charles E.; Heaton, Eleanore C. T.; Best, Tiffany L.; Williams, Robert L.

    2016-01-01

    Though class participation and group cohesion have shown some potential to promote student performance in conventional classrooms, their efficacy has not yet been demonstrated in an online-class setting. Group cohesion, defined as member attraction to and self-identification with a group, is thought to promote positive interdependence and the…

  10. Group Performing in a Problem-Based Curriculum: The Development and Evaluation of an Instrument.

    ERIC Educational Resources Information Center

    van Berkel, Henk J. M.; van Til, Cita T.

    In a problem-based curriculum, emphasis is placed on the groups in which students learn to analyze problems and to contribute to the solution of a problem. This paper describes an instrument that aims to measure individual group performing and presents some psychometric results. Reliability and validity were studied with 240 students in groups of…

  11. Comparison of Group Cohesion, Class Participation, and Exam Performance in Live and Online Classes

    ERIC Educational Resources Information Center

    Galyon, Charles E.; Heaton, Eleanore C. T.; Best, Tiffany L.; Williams, Robert L.

    2016-01-01

    Though class participation and group cohesion have shown some potential to promote student performance in conventional classrooms, their efficacy has not yet been demonstrated in an online-class setting. Group cohesion, defined as member attraction to and self-identification with a group, is thought to promote positive interdependence and the…

  12. Psychological collectivism: a measurement validation and linkage to group member performance.

    PubMed

    Jackson, Christine L; Colquitt, Jason A; Wesson, Michael J; Zapata-Phelan, Cindy P

    2006-07-01

    The 3 studies presented here introduce a new measure of the individual-difference form of collectivism. Psychological collectivism is conceptualized as a multidimensional construct with the following 5 facets: preference for in-groups, reliance on in-groups, concern for in-groups, acceptance of in-group norms, and prioritization of in-group goals. Study 1 developed and tested the new measure in a sample of consultants. Study 2 cross-validated the measure using an alumni sample of a Southeastern university, assessing its convergent validity with other collectivism measures. Study 3 linked scores on the measure to 4 dimensions of group member performance (task performance, citizenship behavior, counterproductive behavior, and withdrawal behavior) in a computer software firm and assessed discriminant validity using the Big Five. The results of the studies support the construct validity of the measure and illustrate the potential value of collectivism as a predictor of group member performance. ((c) 2006 APA, all rights reserved).

  13. Position Affects Performance in Multiple-Object Tracking in Rugby Union Players.

    PubMed

    Martín, Andrés; Sfer, Ana M; D'Urso Villar, Marcela A; Barraza, José F

    2017-01-01

    We report an experiment that examines the performance of rugby union players and a control group composed of graduate student with no sport experience, in a multiple-object tracking task. It compares the ability of 86 high level rugby union players grouped as Backs and Forwards and the control group, to track a subset of randomly moving targets amongst the same number of distractors. Several difficulties were included in the experimental design in order to evaluate possible interactions between the relevant variables. Results show that the performance of the Backs is better than that of the other groups, but the occurrence of interactions precludes an isolated groups analysis. We interpret the results within the framework of visual attention and discuss both, the implications of our results and the practical consequences.

  14. AGT and RH blood group polymorphisms affect blood pressure and lipids in Afro-Caribbeans.

    PubMed

    Robinson, M T; Wilson, T W; Nicholson, G A; Grell, G A C; Etienne, C; Grim, C M; Wilson, D; Grim, C E

    2004-05-01

    Population blood pressure variation is most likely due to multiple genes. This is likely the reason why monogenic testing with the angiotensinogen (AGT) gene polymorphisms on chromosome 1 (1q42-43), especially M235T, has met with negative results, especially in those of African descent. The RH blood group system, also on chromosome 1 (1 p36.2-34), has likewise been associated with blood pressure variation in African-Americans and with the rise in blood pressure with age in whites. Using a random sample of the population, we investigated the combined effects of single and combined variation of the AGTN M235T and RH genotypes on blood pressure, lipids, and lipoprotein concentrations in Afro-Caribbeans aged 18-60 years from the island nation of Dominica. In monogenic analysis, AGT M235T was not associated with blood pressure. However, it was associated with HDL (MM 42+/-23, MT 44+/-12, TT 52+/-14 (P=0.002)). RH genotype was significantly associated with systolic blood pressure (P=0.006) and Apo-A (P=0.003). These effects remained after adjustment for age, gender, weight, and BMI. In the polygenetic analysis, AGT M235T and RH were significantly associated with systolic blood pressure (P=0.037; interaction effects, P=0.068). The association of the AGT M235T with blood pressure across RH blood group haplotypes was then tested. Of the five RH haplotypes available for analysis, the AGT M235T was significantly associated with blood pressure within the "D" haplotype (P=0.01). The RH blood group and gender were significantly associated with systolic blood pressure and Apo-A levels (P=0.005 and 0.012, respectively). All interactions were independent of age and weight. In conclusion, we demonstrate a significant association of AGT M235T with blood pressure and cholesterol metabolism in an Afro-Caribbean population in the "genetic context" of the RH blood group system. Further investigation of these interactions may help understand the effects of genetic factors on

  15. Two-dimensional grouping affects perisaccadic perception of depth and synchrony.

    PubMed

    Aruga, Reiko; Saito, Hideo; Ando, Hideyuki; Watanabe, Junji

    2014-01-01

    There is considerable evidence that, when visual stimuli are presented around the time of a saccade, spatial and temporal perceptions of them are distorted. However, only a small number of previous studies have addressed the perception of a visual image induced by a saccade eye movement (visual image that is dynamically drawn on the retina during a saccade at the speed of the eye movement). Here we investigated three-dimensional and temporal perceptions of the saccade-induced images and found that perceptual grouping of objects has a significant effect on the perceived depth and timing of the images.

  16. Absolute Musicianship for Performers: A Model of General Music Study for High School Performing Groups

    ERIC Educational Resources Information Center

    Orzolek, Douglas

    2004-01-01

    Creating the "comprehensive musician" has been discussed by music educators for many years. While its definition varies, essentially comprehensive musicianship is a means of engaging students in musical learning with a goal of creating greater independence. This can be accomplished by creating a rehearsal setting in which performance and…

  17. Factors affecting the choice of contraceptive method by a group of OEO patients.

    PubMed

    Cochrane, S H

    1975-01-01

    A method of discriminant analysis is described whereby a combination of personal characteristics is established which would best predict whether a woman would choose oral or IUD contraception. The study hypothesized that, at the time of choice, a higher level of motivation is necessary to accept an IUD rather than oral contraception. Approximately 450 patients at a Planned Parenthood clinic in Columbia, South Carolina, were studied between October and December 1970. At the 1% level of significance, it was found that pill users are younger, have fewer children, and are more likely to have used the pill in the last 2 years, compared to IUD users. Income is higher for pill users at the 10% level of significance. Educational levels did not differ between the 2 groups. Other factors were significant at varying levels. It would be possible to establish a combination of variables which would predict the separation between the 2 groups of women. There are problems in this approach. 1 problem is that Planned Parenthood has alw ays stressed the voluntary aspect of contraceptive acceptance.

  18. Exploring the Black Box: An Analysis of Work Group Diversity, Conflict, and Performance.

    ERIC Educational Resources Information Center

    Pelled, Lisa Hope; Eisenhardt, Kathleen M.; Xin, Katherine R.

    1999-01-01

    Tests an integrative model of the relationships among diversity, conflict, and performance, using a sample of 45 electronics-industry worker teams. Functional background diversity drives task conflict; multiple types of diversity drive emotional conflict. Task conflict affects task performance more favorably than does emotional conflict. (102…

  19. Exploring the Black Box: An Analysis of Work Group Diversity, Conflict, and Performance.

    ERIC Educational Resources Information Center

    Pelled, Lisa Hope; Eisenhardt, Kathleen M.; Xin, Katherine R.

    1999-01-01

    Tests an integrative model of the relationships among diversity, conflict, and performance, using a sample of 45 electronics-industry worker teams. Functional background diversity drives task conflict; multiple types of diversity drive emotional conflict. Task conflict affects task performance more favorably than does emotional conflict. (102…

  20. Milking performance evaluation and factors affecting milking claw vacuum levels with flow simulator.

    PubMed

    Enokidani, Masafumi; Kawai, Kazuhiro; Shinozuka, Yasunori; Watanabe, Aiko

    2017-08-01

    Milking performance of milking machines that matches the production capability of dairy cows is important in reducing the risk of mastitis, particularly in high-producing cows. This study used a simulated milking device to examine the milking performance of the milking system of 73 dairy farms and to analyze the factors affecting claw vacuum. Mean claw vacuum and range of fluctuation of claw vacuum (claw vacuum range) were measured at three different flow rates: 5.7, 7.6 and 8.7 kg/min. At the highest flow rate, only 16 farms (21.9%) met both standards of mean claw vacuum ≥35 kPa and claw vacuum range ≤ 7 kPa, showing that milking systems currently have poor milking performance. The factors affecting mean claw vacuum were claw type, milk-meter and vacuum shut-off device; the factor affecting claw vacuum range was claw type. Examination of the milking performance of the milking system using a simulated milking device allows an examination of the performance that can cope with high producing cows, indicating the possibility of reducing the risk of mastitis caused by inappropriate claw vacuum. © 2016 Japanese Society of Animal Science.

  1. Metal toxicity affects predatory stream invertebrates less than other functional feeding groups.

    PubMed

    Liess, Matthias; Gerner, Nadine V; Kefford, Ben J

    2017-08-01

    Ecosystem effects of heavy metals need to be identified for a retrospective risk assessment, and potential impacts need to be predicted for a prospective risk assessment. In this study, we established a strong correlation between the toxic pressure of dissolved metals and invertebrate species. We compiled available data from a wide geographical range of Australian streams that were contaminated with heavy metals [mainly copper (Cu) and zinc (Zn)] and the corresponding invertebrate communities. Heavy metal toxicity is positively related to the proportion of predators within the invertebrate community, represented by the predatorratio, with an effect threshold range of 2.6 μg/L - 26 μg/L for Cu and 62 μg/L - 617 μg/L for Zn. These effect concentrations are in the ranges of the concentrations identified in model ecosystems and other field investigations and are just above the existing guideline limits. Heavy metals also affects the taxa richness negatively. Other community measures, such as the evenness, number of EPT (Ephemeroptera, Plecoptera, and Trichoptera) taxa, SPEcies At Risk (SPEAR)pesticides or SPEARsalinity were relatively poorly correlated with heavy metal toxicity in the streams. Therefore, we suggest applying the predatorratio within the community as a starting point for an indicator of the dissolved metal toxicity, the SPEARmetals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Do increases in selected fitness parameters affect the aesthetic aspects of classical ballet performance?

    PubMed

    Twitchett, Emily A; Angioi, Manuela; Koutedakis, Yiannis; Wyon, Matthew

    2011-03-01

    Research has indicated that classical ballet dancers tend to have lower fitness levels and increased injury rates compared to other athletes with similar workloads. The aim of the current study was to examine the effects of a specifically tailored fitness training programme on the incidence of injury and the aesthetic quality of performance of classical ballet dancers compared to a control group. Proficiency in performance was evaluated at the beginning and end of the intervention period for both groups through a 4-min dance sequence using previously ratified marking criteria. The intervention group (n = 8) partook in a weekly 1-hr training session that included aerobic interval training, circuit training, and whole body vibration. All dancers' performance proficiency scores increased from pre-intervention testing to post-intervention. The intervention group's overall performance scores demonstrated a significantly greater increase (p = 0.03) than the equivalent for the control group. It was concluded that supplementary fitness training has a positive effect on aspects related to aesthetic dance performance as studied herein; further research is recommended on a larger and more varied sample. Practical applications from this study suggest that supplemental training should be part of a ballet dancer's regime, and minimal intervention time is required to have observable effects.

  3. Factors affecting the in vitro activity of cefoperazone against the Bacteroides fragilis group.

    PubMed Central

    Sutter, V L; Kwok, Y Y

    1981-01-01

    The in vitro activity of cefoperazone against 32 strains of bacteria of the Bacteroides fragilis group was determined on four media by using a variety of test parameters. Lower mean minimal inhibitory concentrations (MICs) were obtained on Mueller-Hinton blood agar and supplemented brain heart infusion agar than were obtained on brucella laked blood agar or Wilkins-Chalgren agar. Higher MICs were obtained with 6-h inocula than with 24-h inocula, and slightly higher MICs were obtained with tests read at 48 as compared with 24 h. Conducting tests in an anaerobic glove box had little effect. The greatest differences in mean MICs were seen with inoculum densities of 10(4) and 10(5) colony-forming units. PMID:6459765

  4. Approach/Avoidance Orientations Affect Self-Construal and Identification with In-group

    PubMed Central

    Nussinson, Ravit; Häfner, Michael; Seibt, Beate; Strack, Fritz; Trope, Yaacov

    2011-01-01

    Approach and avoidance are two basic motivational orientations. Their activation influences cognitive and perceptive processes: Previous work suggests that an approach orientation instigates a focus on larger units as compared to avoidance. Study 1 confirms this assumption using a paradigm that more directly taps a person’s tendency to represent objects as belonging to small or large units than prior studies. It was further predicted that the self should also be represented as belonging to larger units, and hence be more interdependent under approach than under avoidance. Study 2 supports this prediction. As a consequence of this focus on belonging to larger units, it was finally predicted that approach results in a stronger identification with one’s in-group than avoidance. Studies 3 and 4 support that prediction. PMID:22844229

  5. How the extinction of extragalactic background light affects surface photometry of galaxies, groups and clusters

    NASA Astrophysics Data System (ADS)

    Zackrisson, E.; Micheva, G.; Östlin, G.

    2009-08-01

    The faint regions of galaxies, groups and clusters hold important clues about how these objects formed, and surface photometry at optical and near-infrared wavelengths represents a powerful tool for studying such structures. Here, we identify a hitherto unrecognized problem with this technique, related to how the night sky flux is typically measured and subtracted from astronomical images. While most of the sky flux comes from regions between the observer and the target object, a small fraction - the extragalactic background light (EBL) - comes from behind. We argue that since this part of the sky flux can be subjected to extinction by dust present in the galaxy/group/cluster studied, standard reduction procedures may lead to a systematic oversubtraction of the EBL. Even very small amounts of extinction can lead to spurious features in radial surface brightness profiles and colour maps of extended objects. We assess the likely impact of this effect on a number of topics in extragalactic astronomy where very deep surface photometry is currently attempted, including studies of stellar haloes, starburst host galaxies, disc truncations and diffuse intragroup/intracluster light. We argue that EBL extinction may provide at least a partial explanation for the anomalously red colours reported for the haloes of disc galaxies and for the hosts of local starburst galaxies. EBL extinction effects also mimic truncations in discs with unusually high dust opacities, but are unlikely to be the cause of such features in general. Failure to account for EBL extinction can also give rise to a non-negligible underestimate of intragroup and intracluster light at the faintest surface brightness levels currently probed. Finally, we discuss how EBL extinction effects may be exploited to provide an independent constraint on the surface brightness of the EBL, using a combination of surface photometry and direct star counts.

  6. 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.

  7. The Experience of a Modern Dance Group: Arousal, Motivation, and Self-Rated Performance

    ERIC Educational Resources Information Center

    Kerr, John H.; Fujiyama, Hakuei; Wilson, George V.; Nakamori, Kayo

    2006-01-01

    The purpose of the present study was to extend the findings obtained in previous reversal theory based dance research by investigating dancers' perceptions of their own arousal levels and performance and their motivational states when performing. A group of modern dancers (n = 21), performing at a dance competition, acted as volunteer…

  8. Working parameters affecting earth-air heat exchanger (EAHE) system performance for passive cooling: A review

    NASA Astrophysics Data System (ADS)

    Darius, D.; Misaran, M. S.; Rahman, Md. M.; Ismail, M. A.; Amaludin, A.

    2017-07-01

    The study on the effect of the working parameters such as pipe material, pipe length, pipe diameter, depth of burial of the pipe, air flow rate and different types of soils on the thermal performance of earth-air heat exchanger (EAHE) systems is very crucial to ensure that thermal comfort can be achieved. In the past decade, researchers have performed studies to develop numerical models for analysis of EAHE systems. Until recently, two-dimensional models replaced the numerical models in the 1990s and in recent times, more advanced analysis using three-dimensional models, specifically the Computational Fluid Dynamics (CFD) simulation in the analysis of EAHE system. This paper reviews previous models used to analyse the EAHE system and working parameters that affects the earth-air heat exchanger (EAHE) thermal performance as of February 2017. Recent findings on the parameters affecting EAHE performance are also presented and discussed. As a conclusion, with the advent of CFD methods, investigational work have geared up to modelling and simulation work as it saves time and cost. Comprehension of the EAHE working parameters and its effect on system performance is largely established. However, the study on type of soil and its characteristics on the performance of EAHEs systems are surprisingly barren. Therefore, future studies should focus on the effect of soil characteristics such as moisture content, density of soil, and type of soil on the thermal performance of EAHEs system.

  9. A quality improvement study on avoidable stressors and countermeasures affecting surgical motor performance and learning.

    PubMed

    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

    2012-06-01

    To explore how the 2 most important components of surgical performance--speed and accuracy-are influenced by different forms of stress and what the impact of music is on these factors. On the basis of 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. Thirty-one surgeons were recruited for a crossover study. Surgeons were randomized to 4 simple standardized tasks to be performed on the SurgicalSIM VR laparoscopic simulator (Medical Education Technologies, Inc, Sarasota, FL), 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). 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. 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 the

  10. 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

  11. How Health Behaviors Relate to Academic Performance via Affect: An Intensive Longitudinal Study

    PubMed Central

    Flueckiger, Lavinia; Lieb, Roselind; Meyer, Andrea H.; Mata, Jutta

    2014-01-01

    Objective This intensive longitudinal study examined how sleep and physical activity relate to university students’ affect and academic performance during a stressful examination period. Methods On 32 consecutive days, 72 first-year students answered online questionnaires on their sleep quality, physical activity, positive and negative affect, learning goal achievement, and examination grades. First-year university students are particularly well-suited to test our hypotheses: They represent a relatively homogeneous population in a natural, but controlled setting, and simultaneously deal with similar stressors, such as examinations. Data were analyzed using multilevel structural equation models. Results Over the examination period, better average sleep quality but not physical activity predicted better learning goal achievement. Better learning goal achievement was associated with increased probability of passing all examinations. Relations of average sleep quality and average physical activity with learning goal achievement were mediated by experienced positive affect. In terms of day-to-day dynamics, on days with better sleep quality, participants reported better learning goal achievement. Day-to-day physical activity was not related to daily learning goal achievement. Daily positive and negative affect both mediated the effect of day-to-day sleep quality and physical activity on daily learning goal achievement. Conclusion Health behaviors such as sleep quality and physical activity seem important for both academic performance and affect experience, an indicator of mental health, during a stressful examination period. These results are a first step toward a better understanding of between- and within-person variations in health behaviors, affect, and academic performance, and could inform prevention and intervention programs for university students. PMID:25353638

  12. How health behaviors relate to academic performance via affect: an intensive longitudinal study.

    PubMed

    Flueckiger, Lavinia; Lieb, Roselind; Meyer, Andrea H; Mata, Jutta

    2014-01-01

    This intensive longitudinal study examined how sleep and physical activity relate to university students' affect and academic performance during a stressful examination period. On 32 consecutive days, 72 first-year students answered online questionnaires on their sleep quality, physical activity, positive and negative affect, learning goal achievement, and examination grades. First-year university students are particularly well-suited to test our hypotheses: They represent a relatively homogeneous population in a natural, but controlled setting, and simultaneously deal with similar stressors, such as examinations. Data were analyzed using multilevel structural equation models. Over the examination period, better average sleep quality but not physical activity predicted better learning goal achievement. Better learning goal achievement was associated with increased probability of passing all examinations. Relations of average sleep quality and average physical activity with learning goal achievement were mediated by experienced positive affect. In terms of day-to-day dynamics, on days with better sleep quality, participants reported better learning goal achievement. Day-to-day physical activity was not related to daily learning goal achievement. Daily positive and negative affect both mediated the effect of day-to-day sleep quality and physical activity on daily learning goal achievement. Health behaviors such as sleep quality and physical activity seem important for both academic performance and affect experience, an indicator of mental health, during a stressful examination period. These results are a first step toward a better understanding of between- and within-person variations in health behaviors, affect, and academic performance, and could inform prevention and intervention programs for university students.

  13. CO2-induced ocean acidification does not affect individual or group behaviour in a temperate damselfish.

    PubMed

    Kwan, Garfield Tsz; Hamilton, Trevor James; Tresguerres, Martin

    2017-07-01

    Open ocean surface CO2 levels are projected to reach approximately 800 µatm, and ocean pH to decrease by approximately 0.3 units by the year 2100 due to anthropogenic CO2 emissions and the subsequent process of ocean acidification (OA). When exposed to these CO2/pH values, several fish species display abnormal behaviour in laboratory tests, an effect proposed to be linked to altered neuronal GABAA- receptor function. Juvenile blacksmith (Chromis punctipinnis) are social fish that regularly experience CO2/pH fluctuations through kelp forest diurnal primary production and upwelling events, so we hypothesized that they might be resilient to OA. Blacksmiths were exposed to control conditions (pH ∼ 7.92; pCO2 ∼ 540 µatm), constant acidification (pH ∼ 7.71; pCO2 ∼ 921 µatm) and oscillating acidification (pH ∼ 7.91, pCO2 ∼ 560 µatm (day), pH ∼ 7.70, pCO2 ∼ 955 µatm (night)), and caught and tested in two seasons of the year when the ocean temperature was different: winter (16.5 ± 0.1°C) and summer (23.1 ± 0.1°C). Neither constant nor oscillating CO2-induced acidification affected blacksmith individual light/dark preference, inter-individual distance in a shoal or the shoal's response to a novel object, suggesting that blacksmiths are tolerant to projected future OA conditions. However, blacksmiths tested during the winter demonstrated significantly higher dark preference in the individual light/dark preference test, thus confirming season and/or water temperature as relevant factors to consider in behavioural tests.

  14. CO2-induced ocean acidification does not affect individual or group behaviour in a temperate damselfish

    PubMed Central

    Kwan, Garfield Tsz

    2017-01-01

    Open ocean surface CO2 levels are projected to reach approximately 800 µatm, and ocean pH to decrease by approximately 0.3 units by the year 2100 due to anthropogenic CO2 emissions and the subsequent process of ocean acidification (OA). When exposed to these CO2/pH values, several fish species display abnormal behaviour in laboratory tests, an effect proposed to be linked to altered neuronal GABAA­ receptor function. Juvenile blacksmith (Chromis punctipinnis) are social fish that regularly experience CO2/pH fluctuations through kelp forest diurnal primary production and upwelling events, so we hypothesized that they might be resilient to OA. Blacksmiths were exposed to control conditions (pH ∼ 7.92; pCO2 ∼ 540 µatm), constant acidification (pH ∼ 7.71; pCO2 ∼ 921 µatm) and oscillating acidification (pH ∼ 7.91, pCO2 ∼ 560 µatm (day), pH ∼ 7.70, pCO2 ∼ 955 µatm (night)), and caught and tested in two seasons of the year when the ocean temperature was different: winter (16.5 ± 0.1°C) and summer (23.1 ± 0.1°C). Neither constant nor oscillating CO2-induced acidification affected blacksmith individual light/dark preference, inter-individual distance in a shoal or the shoal's response to a novel object, suggesting that blacksmiths are tolerant to projected future OA conditions. However, blacksmiths tested during the winter demonstrated significantly higher dark preference in the individual light/dark preference test, thus confirming season and/or water temperature as relevant factors to consider in behavioural tests. PMID:28791154

  15. Group size and nest spacing affect Buggy Creek virus (Togaviridae: Alphavirus) infection in nestling house sparrows.

    PubMed

    O'Brien, Valerie A; Brown, Charles R

    2011-01-01

    The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously affected by BCRV. For house sparrows occupying swallow nesting colonies in western Nebraska, USA, the prevalence of BCRV in nestling sparrows increased with sparrow colony size at a site but decreased with the number of cliff swallows present. If one nestling in a nest was infected with the virus, there was a greater likelihood that one or more of its nest-mates would also be infected than nestlings chosen at random. The closer a nest was to another nest containing infected nestlings, the greater the likelihood that some of the nestlings in the focal nest would be BCRV-positive. These results illustrate that BCRV represents a cost of coloniality for a vertebrate host (the house sparrow), perhaps the first such demonstration for an arbovirus, and that virus infection is spatially clustered within nests and within colonies. The decreased incidence of BCRV in sparrows as cliff swallows at a site increased reflects the "dilution effect," in which virus transmission is reduced when a vector switches to feeding on a less competent vertebrate host.

  16. Group Size and Nest Spacing Affect Buggy Creek Virus (Togaviridae: Alphavirus) Infection in Nestling House Sparrows

    PubMed Central

    O'Brien, Valerie A.; Brown, Charles R.

    2011-01-01

    The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously affected by BCRV. For house sparrows occupying swallow nesting colonies in western Nebraska, USA, the prevalence of BCRV in nestling sparrows increased with sparrow colony size at a site but decreased with the number of cliff swallows present. If one nestling in a nest was infected with the virus, there was a greater likelihood that one or more of its nest-mates would also be infected than nestlings chosen at random. The closer a nest was to another nest containing infected nestlings, the greater the likelihood that some of the nestlings in the focal nest would be BCRV-positive. These results illustrate that BCRV represents a cost of coloniality for a vertebrate host (the house sparrow), perhaps the first such demonstration for an arbovirus, and that virus infection is spatially clustered within nests and within colonies. The decreased incidence of BCRV in sparrows as cliff swallows at a site increased reflects the “dilution effect,” in which virus transmission is reduced when a vector switches to feeding on a less competent vertebrate host. PMID:21966539

  17. Optimizing the electrochemical performance of imidazolium-based polymeric ionic liquids by varying tethering groups

    NASA Astrophysics Data System (ADS)

    Jia, Zhe

    Increasing efforts have been made in the area of sustainable alternative energy devices in the past few decades in order to develop high efficiency, low-cost electrochemical devices with sufficient long-term stability. Due to the drawbacks of conventional organic liquid electrolytes, such as leakage, volatility, flammability, and toxicity, the synthesis of solvent-free electrolyte materials has been studied world-wide. Among all the alternatives, polymer electrolytes are of great interest and have attracted many research groups. Solid-state polymer electrolytes and in particular, polymer ionic liquids (PILs), considered to be promising candidates, have been under studied widely. Ionic Liquids (ILs), defined as organic/inorganic salts with m.p. lower than 100 °C, offer good chemical stability, low flammability, negligible vapor pressure and high ionic conductivity. PILs, as the polymerized state of ILs, not only present some of the unique properties of ILs, but also benefit from the intrinsic properties of polymers, such as better thermal and chemical stability, enhanced mechanical properties, and tunable solution properties. The constrained structure of PILs may help to overcome fabrication and leakage problems associated with simple liquid electrolytes, but typically also leads to lower ionic conductivity. Once polymerized, the ionic conductivity of PILs drops substantially, usually by several orders of magnitude compared to the corresponding monomers. Therefore, to improve PILs chain mobilitiy is crucial. Previous studies suggest that a flexible tethering group should make the polymer backbone less rigid and increase electrolyte ion mobility. To investigate how tethering groups affect both electrochemical performance and physical properties of free ILs and PILs, we first report the synthesis and characterization of a novel class of imidazolium (Im) based IL model compounds and their corresponding PILs. Poly(ethylene oxide)s (PEOs), considered to be promising

  18. Strategic groups and performance in the nursing home industry: a reexamination.

    PubMed

    Marlin, D; Sun, M; Huonker, J W

    1999-06-01

    This study further examines the relationship between strategic group membership and performance in the nursing home industry. The results indicate seven strategic groups in the industry with significant between-group differences in operating margin, average profit per patient day, catheterization rate, health deficiencies, life and safety deficiencies, and efficiency in the provision of services. The authors did not, however, find significant between-group differences in pressure sore rate, the use of restraints, or in the percentage of patients with significant unplanned weight changes. The group with the highest private-pay utilization combined with high Medicare utilization generally performed the best along all indicators. Results also suggest that strategic group membership and rural/urban location have a greater impact on performance than do ownership, chain membership, or possession of a dedicated specialty care unit.

  19. Affective Balance, Team Prosocial Efficacy and Team Trust: A Multilevel Analysis of Prosocial Behavior in Small Groups.

    PubMed

    Cuadrado, Esther; Tabernero, Carmen

    2015-01-01

    Little research has focused on how individual- and team-level characteristics jointly influence, via interaction, how prosocially individuals behave in teams and few studies have considered the potential influence of team context on prosocial behavior. Using a multilevel perspective, we examined the relationships between individual (affective balance) and group (team prosocial efficacy and team trust) level variables and prosocial behavior towards team members. The participants were 123 students nested in 45 small teams. A series of multilevel random models was estimated using hierarchical linear and nonlinear modeling. Individuals were more likely to behave prosocially towards in-group members when they were feeling good. Furthermore, the relationship between positive affective balance and prosocial behavior was stronger in teams with higher team prosocial efficacy levels as well as in teams with higher team trust levels. Finally, the relevance of team trust had a stronger influence on behavior than team prosocial efficacy.

  20. Affective Balance, Team Prosocial Efficacy and Team Trust: A Multilevel Analysis of Prosocial Behavior in Small Groups

    PubMed Central

    Cuadrado, Esther; Tabernero, Carmen

    2015-01-01

    Little research has focused on how individual- and team-level characteristics jointly influence, via interaction, how prosocially individuals behave in teams and few studies have considered the potential influence of team context on prosocial behavior. Using a multilevel perspective, we examined the relationships between individual (affective balance) and group (team prosocial efficacy and team trust) level variables and prosocial behavior towards team members. The participants were 123 students nested in 45 small teams. A series of multilevel random models was estimated using hierarchical linear and nonlinear modeling. Individuals were more likely to behave prosocially towards in-group members when they were feeling good. Furthermore, the relationship between positive affective balance and prosocial behavior was stronger in teams with higher team prosocial efficacy levels as well as in teams with higher team trust levels. Finally, the relevance of team trust had a stronger influence on behavior than team prosocial efficacy. PMID:26317608

  1. Disturbance gradient shows logging affects plant functional groups more than fire.

    PubMed

    Blair, David P; McBurney, Lachlan M; Blanchard, Wade; Banks, Sam C; Lindenmayer, David B

    2016-10-01

    Understanding the impacts of natural and human disturbances on forest biota is critical for improving forest management. Many studies have examined the separate impacts on fauna and flora of wildfire, conventional logging, and salvage logging, but empirical comparisons across a broad gradient of simultaneous disturbances are lacking. We quantified species richness and frequency of occurrence of vascular plants, and functional group responses, across a gradient of disturbances that occurred concurrently in 2009 in the mountain ash forests of southeastern Australia. Our study encompassed replicated sites in undisturbed forest (~70 yr post fire), forest burned at low severity, forest burned at high severity, unburned forest that was clearcut logged, and forest burned at high severity that was clearcut salvage logged post-fire. All sites were sampled 2 and 3 yr post fire. Mean species richness decreased across the disturbance gradient from 30.1 species/site on low-severity burned sites and 28.9 species/site on high-severity burned sites, to 25.1 species/site on clearcut sites and 21.7 species/site on salvage logged sites. Low-severity burned sites were significantly more species-rich than clearcut sites and salvage logged sites; high-severity burned sites supported greater species richness than salvage logged sites. Specific traits influenced species' sensitivity to disturbance. Resprouting species dominated undisturbed mountain ash forests, but declined significantly across the gradient. Fern and midstory trees decreased significantly in frequency of occurrence across the gradient. Ferns (excluding bracken) decreased from 34% of plants in undisturbed forest to 3% on salvage logged sites. High-severity burned sites supported a greater frequency of occurrence and species richness of midstory trees compared to clearcut and salvage logged sites. Salvage logging supported fewer midstory trees than any other disturbance category, and were distinctly different from

  2. Performance and sleepiness during a 24 h wake in constant conditions are affected by diet.

    PubMed

    Lowden, Arne; Holmbäck, Ulf; Akerstedt, Torbjörn; Forslund, Jeanette; Lennernäs, Maria; Forslund, Anders

    2004-02-01

    This study investigated the effects of high-carbohydrate (HC) and high-fat (HF) diet on cognitive performance, and subjective and objective sleepiness. Seven male participants were kept awake for 24 h in a metabolic ward. Meals were given every 4h and cognitive performance and sleepiness ratings were assessed hourly. The Karolinska Drowsiness Test (KDT, EEG derived) was performed twice after meal. Performance in simple reaction time showed a significant interaction of diet and the post-prandial period, a slower reaction time was observed for the HC-diet 3.5 h after meal intake. Diet did not affect EEG measures but a general post-prandial increase of objective sleepiness was observed 3.5h after meal servings. The HC-diet was significantly associated with an increase of subjective sleepiness. The study demonstrated that the HC-diet caused larger oscillation in performance and increased sleepiness as compared to HF-diet throughout day and night.

  3. 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.

  4. Performance trends in age group breaststroke swimmers in the FINA World Championships 1986-2014.

    PubMed

    Knechtle, Beat; Nikolaidis, Pantelis Theodoros; Rosemann, Thomas; Rüst, Christoph Alexander

    2016-10-31

    Performance trends in breaststroke swimmers competing at world class level in pool competitions are well investigated for elite swimmers, but not for age group swimmers. This study investigated trends in participation, performance and sex difference in performance in a total of 35,143 (16,160 women and 18,983 men) age group breaststroke swimmers aged 25-29 to 95-99 years competing in the Fédération Internationale de Natation (FINA) World Masters Championships between 1986 and 2014. Trends in participation were analysed using linear regression analyses and trends in performance were investigated using mixed-effects regression analyses with sex, distance and calendar year as fixed variables. Women and men improved performance in all age groups. For age groups 25-29 to 85-89 years, men were faster than women. For age groups 90-94 to 95-99 years, men were not faster than women. Sex and distance showed a significant interaction for all distances in age groups 25-29 to 80-84 years. In 50 m, women reduced the gap to men in age groups 40-44 to 70-74 years and in 100 m and 200 m, women reduced the gap in age groups 50-54 to 60-64 years. In summary, (i) women and men improved performance in all race distances and in all age groups, (ii) men were faster than women from 25 to 89 years, but not from 90 to 99 years, and (iii), women reduced the gap to men between ~40 and ~75 years, but not in younger (<40 years) or older (>75 years) age groups. Based on these findings for a time period of nearly 30 years, we may assume a further increase in participation and a further improvement in performance in the near future in age group breaststroke swimmers competing at world class level.

  5. How Does the Concentration of Determinants Affect Industrial Innovation Performance? – An Empirical Analysis of 23 Chinese Industrial Sectors

    PubMed Central

    Huang, Shansong; Bai, Yang; Tan, Qingmei

    2017-01-01

    The agglomeration of innovation determinants has a significant influence on the innovation performance of industries and enterprises. Such an effect has received less attention in empirical research studies. This study involves a survey of the agglomeration effect of two important innovation determinants, R&D investment and R&D personnel, and its influence on innovation performance from the perspective of the industrial level. We analysed the agglomeration features based on the panel data of 23 Chinese industrial sectors from 2001~2013. An interpretation model is proposed to examine the agglomeration effect on innovation performance for 4 industrial groups: state-owned enterprises, individual enterprises, foreign-owned enterprises and enterprises as a whole. We found two main results. First, the agglomeration of determinants has a clear positive effect on the innovation performance of all 4 groups but affects individual enterprises more significantly, followed by state-owned and foreign-owned enterprises. Second, the state-owned enterprises show a much higher concentration of R&D investment and R&D personnel than other groups. However, the induced innovation efficiency in the state-owned enterprises is worse than in the individual enterprises. The advantage of resources and capital does not translate into corresponding innovation output. The privately owned small and medium-sized enterprises (SMEs) show a high capability of technological innovation and mercerization but have limited innovation resources. PMID:28099452

  6. How Does the Concentration of Determinants Affect Industrial Innovation Performance? - An Empirical Analysis of 23 Chinese Industrial Sectors.

    PubMed

    Huang, Shansong; Bai, Yang; Tan, Qingmei

    2017-01-01

    The agglomeration of innovation determinants has a significant influence on the innovation performance of industries and enterprises. Such an effect has received less attention in empirical research studies. This study involves a survey of the agglomeration effect of two important innovation determinants, R&D investment and R&D personnel, and its influence on innovation performance from the perspective of the industrial level. We analysed the agglomeration features based on the panel data of 23 Chinese industrial sectors from 2001~2013. An interpretation model is proposed to examine the agglomeration effect on innovation performance for 4 industrial groups: state-owned enterprises, individual enterprises, foreign-owned enterprises and enterprises as a whole. We found two main results. First, the agglomeration of determinants has a clear positive effect on the innovation performance of all 4 groups but affects individual enterprises more significantly, followed by state-owned and foreign-owned enterprises. Second, the state-owned enterprises show a much higher concentration of R&D investment and R&D personnel than other groups. However, the induced innovation efficiency in the state-owned enterprises is worse than in the individual enterprises. The advantage of resources and capital does not translate into corresponding innovation output. The privately owned small and medium-sized enterprises (SMEs) show a high capability of technological innovation and mercerization but have limited innovation resources.

  7. Factors affecting the identification of phytoplankton groups by means of remote sensing

    NASA Technical Reports Server (NTRS)

    Weaver, Ellen C.; Wrigley, Robert

    1994-01-01

    A literature review was conducted on the state of the art as to whether or not information about communities and populations of phytoplankton in aquatic environments can be derived by remote sensing. In order to arrive at this goal, the spectral characteristics of various types of phytoplankton were compared to determine first, whether there are characteristic differences in pigmentation among the types and second, whether such differences can be detected remotely. In addition to the literature review, an extensive, but not exhaustive, annotated bibliography of the literature that bears on these questions is included as an appendix, since it constitutes a convenient resource for anyone wishing an overview of the field of ocean color. The review found some progress has already been made in remote sensing of assemblages such as coccolithophorid blooms, mats of cyanobacteria, and red tides. Much more information about the composition of algal groups is potentially available by remote sensing particularly in water bodies having higher phytoplankton concentrations, but it will be necessary to develop the remote sensing techniques required for working in so-called Case 2 waters. It is also clear that none of the satellite sensors presently available or soon to be launched is ideal from the point of view of what we might wish to know; it would seem wise to pursue instruments with the planned characteristics of the Moderate Resolution Imaging Spectrometer-Tilt (MODIS-T) or Medium Resolution Imaging Spectrometer (MERIS).

  8. Time spent in home meal preparation affects energy and food group intakes among midlife women.

    PubMed

    Chu, Yen Li; Addo, O Yaw; Perry, Courtney D; Sudo, Noriko; Reicks, Marla

    2012-04-01

    Time spent in meal preparation may be indicative of the healthfulness of meals and therefore with weight status. The purpose of this study was to examine the association between amount of time spent preparing meals and meal food group and nutrient content by meal occasion (breakfast, lunch, and dinner) among 1036 midlife women. Participants completed a 1-day food record and eating occasion questionnaires for each meal occasion. ANCOVA was used to identify possible associations. Approximately half of the participants reported spending <5 min preparing breakfast and lunch, and <20 min preparing dinner. Less time spent preparing breakfast was associated with lower energy and fat intakes (p<0.0001), while less time spent preparing lunch and dinner was associated with lower vegetable and sodium intakes (p<0.0001). There were no apparent differences in the association between time spent preparing meals and meal content by weight status. Nutrition education should encourage home meal preparation while stressing the selection of healthier options. The differing associations by meal occasion suggest that interventions should be tailored according to meal type. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Evaluating HIV prevention strategies for populations in key affected groups: The example of Cabo Verde

    PubMed Central

    Monteiro, João Filipe G.; Galea, Sandro; Flanigan, Timothy; Monteiro, Maria de Lourdes; Friedman, Samuel R.; Marshall, Brandon DL

    2015-01-01

    Objectives We used an individual-based model to evaluate the effects of hypothetical prevention interventions on HIV incidence trajectories in a concentrated, mixed epidemic setting from 2011 to 2021, and using Cabo Verde as an example. Methods Simulations were conducted to evaluate the extent to which early HIV treatment and optimization of care, HIV testing, condom distribution, and substance abuse treatment could eliminate new infections (i.e., reduce incidence to less than 10 cases per 10,000 person-years) among non-drug users, female sex workers (FSW), and people who use drugs (PWUD). Results Scaling up all four interventions resulted in the largest decreases in HIV, with estimates ranging from 1.4 (95%CI:1.36–1.44) per 10,000 person-years among non-drug users to 8.2 (95%CI:7.8–8.6) per 10,000 person-years among PWUD in 2021. Intervention scenarios targeting FWS and PWUD also resulted in HIV incidence estimates at or below 10 per 10,000 person-years by 2021 for all population sub-groups. Conclusions Our results suggest that scaling up multiple interventions among entire population is necessary to achieve elimination. However, prioritizing key populations with this combination prevention strategy may also result in a substantial decrease in total incidence. PMID:25838121

  10. Relationship of biomedical science content acquisition performance to students' level of PBL group interaction: are students learning during PBL group?

    PubMed

    Romito, Laura M; Eckert, George J

    2011-05-01

    This study assessed biomedical science content acquisition from problem-based learning (PBL) and its relationship to students' level of group interaction. We hypothesized that learning in preparation for exams results primarily from individual study of post-case learning objectives and that outcomes would be unrelated to students' group involvement. During dental curricular years 1 and 2, student-generated biomedical learning issues (LIs) were identified from six randomly chosen PBL cases. Knowledge and application of case concepts were assessed with quizzes based on the identified LIs prior to dissemination of the learning objectives. Students and facilitators were surveyed on students' level of group involvement for the assessed LI topics. Year 1 students had significantly higher assessment scores (p=0.0001). For both student classes, means were significantly higher for the recall item (Q1) than for the application item (Q2). Q1 scores increased along with the student's reported role for Year 1 (p=0.04). However, there was no relationship between the student's reported role and Q1 for Year 2 (p=0.20). There was no relationship between the student's reported role and Q2 for Year 1 (p=0.09) or Year 2 (p=0.19). This suggests that students' level of group involvement on the biomedical learning issues did not significantly impact students' assessment performance.

  11. Using technology-enhanced, cooperative, group-project learning for student comprehension and academic performance

    NASA Astrophysics Data System (ADS)

    Tlhoaele, Malefyane; Suhre, Cor; Hofman, Adriaan

    2016-05-01

    Cooperative learning may improve students' motivation, understanding of course concepts, and academic performance. This study therefore enhanced a cooperative, group-project learning technique with technology resources to determine whether doing so improved students' deep learning and performance. A sample of 118 engineering students, randomly divided into two groups, participated in this study and provided data through questionnaires issued before and after the experiment. The results, obtained through analyses of variance and structural equation modelling, reveal that technology-enhanced, cooperative, group-project learning improves students' comprehension and academic performance.

  12. Factors affecting the glucosinolate content of kale (Brassica oleracea acephala group).

    PubMed

    Velasco, Pablo; Cartea, María Elena; Gonzalez, Carmen; Vilar, Marta; Ordas, Amando

    2007-02-07

    Kales (Brassica oleracea acephala group) are important vegetable crops in traditional farming systems in the Iberian Peninsula. They are grown throughout the year to harvest their leaves and flower buds. The glucosinolate content of kales is dependent upon the environmental factors, plant part examined, phenological stage of plant growth, and level of insect damage. The objectives of this study were to evaluate the changes in the total and individual glucosinolate concentrations during plant development and to determine if significant variation of glucosinolate levels can be explained by insect pests attack and other environmental factors in four locations in northwestern Spain. The total glucosinolate concentration in leaves of B. oleracea increased with plant age from seedling to early flowering stages. At that stage, the aliphatic glucosinolate content in leaves of B. oleracea declined drastically over time as the content in the flower buds increased. The highest contents of indolyl glucosinolate (glucobrassicin) and of the aromatic glucosinolate occurred in leaves harvested at the optimum consumption stage while flower buds contained the highest concentration of aliphatic glucosinolates, especially sinigrin. Sinigrin is reported to have anticarcinogenic properties. There appears to be a loss of total and individual glucosinolate concentrations related to pest attack. Leaves damaged by lepidopterous pests contained a lower total glucosinolate content (25.8 micromol g-1 dw) than undamaged leaves (41 micromol g-1 dw). The amounts of sinigrin, glucoiberin, and glucobrassicin were also lowest in insect-damaged leaves. Environmental factors such as soil properties and temperature appear to influence the glucosinolate content in leaves although more research on this subject is needed.

  13. 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.

  14. 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).

  15. An action-research study exploring midwives' support needs and the affect of group clinical supervision.

    PubMed

    Deery, Ruth

    2005-06-01

    To explore community midwives' views and experiences of their support needs in clinical practice, and then to identify how they would wish to receive such support. Further objectives were to redress the imbalance identified by planning and facilitating a model of clinical supervision devised by the participating midwives. A qualitative study using an action-research approach based on collaboration and participation. Action research has the potential to facilitate understanding of, and is able to adapt to, changing situations within clinical practice. Data were collected in three phases using in-depth interviews and focus groups. A large maternity unit in the north of England, UK. Eight National Health Service (NHS) community midwives working in the same team. Recent and ongoing organisational change and increased demands placed on the midwives by their managers were found to be detrimental to the process of clinical supervision and working relationships with their peers and clients. These pressures also inhibited the process of change. The midwives' behaviour and coping strategies revealed an apparent lack of understanding on their part, and that of their midwifery managers, of the regulation of emotion and the amount of energy this generated. Pseudo-cohesion and resistance to change were key defence mechanisms used by the participating midwives. A large amount of published literature supported the existence of stress and burnout in midwifery, but no research addressed ways of alleviating this situation. Effective facilitation of midwifery support is needed, which can be met through support mechanisms such as clinical supervision. During the process of clinical supervision, strong messages emerged about the necessity to ensure that midwives are prepared educationally for the difficult situations that are brought about through collaborative working. There are also messages about the cultural legacy of NHS midwifery and how this can inhibit autonomous behaviour by

  16. How self-reported hot flashes may relate to affect, cognitive performance and sleep.

    PubMed

    Regestein, Quentin; Friebely, Joan; Schiff, Isaac

    2015-08-01

    To explain the controversy about whether midlife women who self-report hot flashes have relatively increased affective symptoms, poor cognitive performance or worse sleep. Retrospective data from 88 women seeking relief from bothersome day and night hot flashes were submitted to mixed linear regression modeling to find if estimated hot flashes, as measured by Women's Health Questionnaire (WHQ) items, or diary-documented hot flashes recorded daily, were associated with each other, or with affective, cognitive or sleep measures. Subjects averaged 6.3 daytime diary-documented hot flashes and 2.4 nighttime diary-documented hot flashes per 24h. Confounder-controlled diary-documented hot flashes but not estimated hot flashes were associated with increased Leeds anxiety scores (F=4.9; t=2.8; p=0.01) and Leeds depression scores (3.4; 2.5; 0.02), decreased Stroop Color-Word test performance (9.4; 3.5; 0.001), increased subjective sleep disturbance (effect size=0.83) and increased objective sleep disturbance (effect size=0.35). Hot flash effects were small to moderate in size. Univariate but not multivariate analyses revealed that all hot flash measures were associated with all affect measures. Different measures of hot flashes associated differently with affect, cognition and sleep. Only nighttime diary-document hot flash consistently correlated with any affect measures in multivariate analyses. The use of differing measures for hot flashes, affect, cognition and sleep may account for the continually reported inconsistencies in menopause study outcomes. This problem impedes forging a consensus on whether hot flashes correlate with neuropsychological symptoms. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. 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

  18. 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

    2014-05-08

    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.

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

    PubMed Central

    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

  20. 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.