A New Path-Integral Representation of the TT-Matrix in Potential Scattering

We employ the method used by Barbashov and collaborators in Quantum Field Theory to derive a path-integral representation of the $T$-matrix in nonrelativistic potential scattering which is free of functional integration over fictitious variables as was necessary before. The resulting expression serves as a starting point for a variational approximation applied to high-energy scattering from a Gaussian potential. Good agreement with exact partial-wave calculations is found even at large scattering angles. A novel path-integral representation of the scattering length is obtained in the low-energy limit.Comment: 9 pages, 1 figure, Latex with amsmath, amssym; v2: some typos corrected, matches published versio

Development of a Cohesion Questionnaire for Youth: The Youth Sport Environment Questionnaire

The purpose of the current study was to initiate the development of a psychometrically sound measure of cohesion for youth sport groups. A series of projects were undertaken in a four-phase research program. The initial phase was designed to garner an understanding of how youth sport group members perceived the concept of cohesion through focus groups (n = 56), open-ended questionnaires (n = 280), and a literature review. In Phase 2, information from the initial projects was used in the development of 142 potential items and content validity was assessed. In Phase 3, 227 participants completed a revised 87-item questionnaire. Principal components analyses further reduced the number of items to 17 and suggested a two-factor structure (i.e., task and social cohesion dimensions). Finally, support for the factorial validity of the resultant questionnaire was provided through confirmatory factor analyses with an independent sample (n = 352) in Phase 4. The final version of the questionnaire contains 16 items that assess task and social cohesion in addition to 2 negatively worded spurious items. Specific issues related to assessing youth perceptions of cohesion are discussed and future research directions are suggested

Thrift Industry Crisis: Causes and Solutions

macroeconomics, thrift industry, crisis, competition, financial services, regulation

Item Wording and Internal Consistency of a Measure of Cohesion: The Group Environment Questionnaire

A common practice for counteracting response acquiescence in psychological measures has been to employ both negatively and positively worded items. However, previous research has highlighted that the reliability of measures can be affected by this practice (Spector, 1992). The purpose of the present study was to examine the effect that the presence of negatively worded items has on the internal reliability of the Group Environment Questionnaire (GEQ). Two samples (N = 276) were utilized, and participants were asked to complete the GEQ (original and revised) on separate occasions. Results demonstrated that the revised questionnaire (containing all positively worded items) had significantly higher Cronbach α values for three of the four dimensions of the GEQ. Implications, alternatives, and future directions are discussed

A Novel Risky Decision-Making Task in High and Low Alcohol Preferring Mice

Indiana University-Purdue University Indianapolis (IUPUI)Deficits in impulse control and decision-making have been implicated in the development and maintenance of alcohol use disorders (AUDs). Individuals with AUD often make disadvantageous choices under conditions of probabilistic risk. The Iowa Gambling Task (IGT) is often used to measure risky decision-making, in which impaired individuals tend to favor large, infrequent rewards even when punished for these choices, rather than smaller, safer, and more advantageous rewards. It remains poorly understood if these deficits are behaviors under genetic control and if ethanol intoxication may alter decision-making. High and Low Alcohol Preferring (HAP3 and LAP3, respectively) mice were trained on a novel gambling task to investigate these possible influences. In Experiment 1, HAP3s and LAP3s responded for a 0.1% saccharin solution, choosing between a risky and a safe option. Importantly, choosing the risky option was meant to be ultimately disadvantageous. In Experiment 2, these same HAP3 mice responded for saccharin or saccharin plus 10% ethanol. Contrary to hypothesis, LAP3s preferred the risky option more than HAP3s. Alcohol increased preference for the risky lever, but only in male mice. HAP3 preference for the safe lever may be explained by higher motivation to obtain sweet rewards, or higher overall avidity for responding. Ethanol-induced changes in male risk behavior may be explained by higher androgen levels, but further investigation is required. Similarly, continued research is necessary to optimize a risky decision-making task for both lines, and thus investigate possible genetic differences in risk acceptance that correlate with differences in alcohol intake

Role Ambiguity in Sport Teams

The general purpose of the present study was to examine the nature of role ambiguity in sport teams and to explore the construct validity of the operational definition of role ambiguity developed by Beauchamp, Bray, Eys, and Carron (2002). Role ambiguity was operationalized as a multidimensional construct (Scope of Responsibilities, Behavioral Responsibilities, Evaluation of Performance, and Consequences of Not Fulfilling Responsibilities) that occurs in two contexts, offense and defense. Consistent with the a priori hypothesis, perceptions of role ambiguity exhibited some degree of within-group consistency and group-level variability, but most of the variance in role ambiguity was seen at the individual level. Also, perceptions of role ambiguity decreased from early to late season. Finally, veteran athletes experienced less role ambiguity than first-year athletes at the beginning of the season, but not at the end. Implications of the findings and suggestions for future research are discussed

The Effect of Role Ambiguity on Competitive State Anxiety

The purpose of this study was to examine the relationship between role ambiguity and precompetition state anxiety (A-state). Consistent with multidimensional anxiety theory (Martens, Vealey, & Burton, 1990), it was hypothesized that role ambiguity would be positively related to cognitive but not to somatic A-state. Based on the conceptual model presented by Beauchamp, Bray, Eys, and Carron (2002), role ambiguity in sport was operationalized as a multidimensional construct (i.e., scope of responsibilities, role behaviors, role evaluation, and role consequences) potentially manifested in each of two contexts, offense and defense. Consistent with hypotheses, ambiguity in terms of the scope of offensive role responsibilities predicted cognitive A-state (R2 = .19). However, contrary to hypotheses, offensive role-consequences ambiguity also predicted somatic A-state (R2 = .09). Results highlight the importance of using a multidimensional approach to investigate role ambiguity in sport and are discussed in terms of both theory advancement and possible interventions

The Relationship Between Task Cohesion and Competitive State Anxiety

The general purpose of the present study was to determine if perceptions of team cohesion are related to the interpretation athletes attach to their precompetition anxiety. Specifically examined was the association between athlete perceptions of task cohesiveness (Individual Attractions to the Group–Task, ATG-T, and Group Integration–Task, GI-T) and the degree to which perceptions of the intensity of precompetition anxiety symptoms (cognitive and somatic) were viewed as facilitative versus debilitative. Participants were athletes (N = 392) from the sports of soccer, rugby, and field hockey. Each athlete completed the Group Environment Questionnaire (Carron, Widmeyer, & Brawley, 1985) after a practice session. A directionally modified version of the Competitive State Anxiety Inventory-2 (Martens, Burton, Vealey, Bump, & Smith, 1990) was completed just prior to a competition. Results showed that athletes who perceived their cognitive anxiety as facilitative had higher perceptions of both ATG-T and GI-T, χ2 (2, N = 260) = 8.96, p \u3c .05, than athletes who perceived their cognitive anxiety as debilitative. Also, athletes who perceived their somatic anxiety as facilitative had higher perceptions of GI-T, χ2 (2, N = 249) = 5.85, p \u3c .05

Variational approximations in a path integral description of potential scattering

Abstract.: Using a recent path integral representation for the T -matrix in nonrelativistic potential scattering we investigate new variational approximations in this framework. By means of the Feynman-Jensen variational principle and the most general ansatz quadratic in the velocity variables --over which one has to integrate functionally-- we obtain variational equations which contain classical elements (trajectories) as well as quantum-mechanical ones (wave spreading). We analyse these equations and solve them numerically by iteration, a procedure best suited at high energy. The first correction to the variational result arising from a cumulant expansion is also evaluated. Comparison is made with exact partial-wave results for scattering from a Gaussian potential and better agreement is found at large scattering angles where the standard eikonal-type approximations fai

Cleaning Up the Depository Institutions Mess

macroeconomics, depository institution