Electronic [re]constitution of groups: Group dynamics from face-to-face to an online setting

The authors work as online tutors for a BSc (Hons) physiotherapy programme at Coventry University in the United Kingdom. This paper represents a stage in our developing understanding, over a 3 year period, of the impact of group dynamics on online interaction among physiotherapy students engaged in sharing with their peers their first experiences of clinical practice. The literature exploring online interaction tends to situate meaning either in theories borrowed from conventional face-to-face interaction or on virtual interaction. Research focusing on ‘blended learning’ that combines face-to-face and online interaction is limited in terms of considering how group dynamics impact groups that are constituted and reconstituted in the two very different learning contexts. Using a case study approach, the authors consider how group dynamics change as groups move from face-to-face to online collaboration in pursuit of learning objectives. We characterize typical features of the cases and draw conclusions based on similarities and differences. Findings suggest that group learning is linked to group cohesion, which appears to be mediated by social and cognitive factors that students bring with them. Social presence appears vital to positive group dynamics and is a precursor to cognitive presence, which develops when groups rise above their desire to be sociable and supportive. Group dynamics, whether positive or negative, and their consequent impact on interaction appear to be relatively stable across contexts once the group scene is set through face-to-face interaction. Engagement and interaction of individual students, however, can alter when face-to-face interaction moves online.     

The effect of participatory and supervisory leadership on group creativity.

This study compares the creativity of 4-man groups under 2 conditions of leadership. The Ss were 90 freshmen and sophomore Navy ROTC midshipmen and 30 NROTC seniors who served as group leaders. In 15 of the groups, the leaders acted as chairmen who directed the group discussions and contributed to the task solution. In the other 15 groups, leaders acted in a supervisory capacity: they directed and guided group discussion and they were allowed to encourage members or to reject ideas, but the leaders were prohibited from contributing to the solution of the task. Groups having participatory leaders were generally superior in quantity of output while groups under supervisory leaders were superior in the quality of the product. Although leaders in the 2 conditions did not differ in their satisfaction with the group product, the participatory leaders were more satisfied with their own individual contribution to the task. The leadership styles did not produce differences in the members' esteem for the leader or in the members' morale and satisfaction with the task. Differences were found in the influence of the leader intelligence and ability scores on group creativity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maximizing Agreements with One-Sided Error with Applications to Heuristic Learning

We study heuristic learnability of classes of Boolean formulas, a model proposed by Pitt and Valiant. In this type of example-based learning of a concept class C by a hypothesis class H, the learner seeks a hypothesis h H that agrees with all of the negative (resp. positive) examples, and a maximum number of positive (resp. negative) examples. This learning is equivalent to the problem of maximizing agreement with a training sample, with the constraint that the misclassifications be limited to examples with positive (resp. negative) labels. Several recent papers have studied the more general problem of maximizing agreements without this one-sided error constraint. We show that for many classes (though not all), the maximum agreement problem with one-sided error is more difficult than the general maximum agreement problem. We then provide lower bounds on the approximability of these one-sided error problems, for many concept classes, including Halfspaces, Decision Lists, XOR, k-term DNF, and neural nets.Editor Philip M. LongThis research was supported by the fund for promotion of research at the Technion. Research no. 120-025.     

Optical metal ion sensor based on diffusion followed by an immobilizing reaction. Quantitative analysis by a mesoporous monolith containing functional groups

A new optical metal ion sensor based on diffusion followed by an immobilizing reaction has been developed. The current sensor is based on a model that unifies two fundamental processes which a metal analyte undergoes when it is exposed to a porous, ligand-grafted monolith: (a) diffusion of metal ions to the binding sites and (b) metal-ligand (ML(n)) complexation. A slow diffusion of the metal ions is followed by their fast immobilizing reaction with the ligands in the monolith to give a complex. Inside the region where the ligands have been saturated, the diffusion of the metal ions reaches a steady state with a constant external metal ion concentration (C(0)). If the complex ML(n) could be observed spectroscopically, the absorbance of the product A(p) follows: A(p) = Kt(1/2), K = 2epsilon(p)(L(0)C(0)D)(1/2). D = diffusion constant of the metal ions inside the porous solid; L(0) = concentration of the ligands grafted in the monolith; and t = time. This equation is straightforward to use, and the K vs C(0)(1/2) plot provides the correlations with the concentrations (C(0)) of the metal ions. This is a rare optical sensor for quantitative metal ion analysis. The use of the model in a mesoporous sol-gel monolith containing grafted amine ligands for quantitative Cu(2+) sensing is demonstrated. This model may also be used in other chemical sensors that depend on diffusion of analytes followed by immobilizing reactions in porous sensors containing grafted/encapsulated functional groups/molecules.     

A taxing environment: evaluating the multiple objectives of environmental taxes

Environmental taxes have attracted attention in recent years as a tool to internalize environmental externalities. This paper evaluates Sweden's experience with environmental taxes in the energy sector by examining how environmental taxes compare with estimated environmental externalities associated with the use of oil, coal, natural gas, and forest residue fuels. We also analyze how environmental taxes influence fuel choices in the energy sector by comparing the production, environmental, and tax costs for the same fuels. We find that (i) the Swedish environmental taxes correspond imperfectly with environmental costs; (ii) the Swedish tax and subsidy system introduces changes in fuel choice decisions; (iii) the energy users are responding to the incentives created by the tax and subsidy systems in ways that are consistent with economic theory; and (iv) the Swedish experience with environmental taxes and subsidies bears directly on wider evaluations of energy policy approaches internationally.     

Evolution of nitrogen species air pollutants along trajectories crossing the Los Angeles area

Ambient aerosol sampling was conducted in Diamond Bar, Mira Loma, and Riverside, CA, to observe at close range the effects of ammonia emissions on air quality. These sites are located upwind,within, and downwind, respectively, of the Chino dairy area, the largest single source of ammonia emissions in the Los Angeles area. Inertial impactors and bulk filter samplers provided 4-7-h measurements of aerosol chemical composition and size distribution. Daily average fine particle mass concentrations were in the range 22.4-143.0 microg m(-3). On some days the fine particulate matter concentrations were more than two times greater than the proposed 24-h Federal standard of 65 microg m(-3). Ammonium nitrate was the largest component of fine particle mass at all three sites; 24-h average fine particulate ammonium plus nitrate concentrations ranged from 11.7 to 75.4 microg m(-3). A single air mass was studied as it passed the Diamond Bar air monitoring site in the morning and stagnated near Mira Loma in the evening of the same day. Between these two sites NO was oxidized to NO2, and the ammonia concentration increased by a factor of 5. A second air parcel trajectory, which stagnated near Mira Loma during the early morning and passed near the Riverside site approximately 24 h later, showed a decrease in ammonia concentration over time that is consistent with dilution as the air mass moved downwind from the source of ammonia in the dairy area. Particulate NH4NO3 concentration in that air parcel remained approximately constant over time, consistent with a continued excess of NH3 relative to HNO3 downwind of the dairy area.     

家居产品用杀菌剂

随着生活环境中卫生标准的要求和不断提高,杀菌剂的应用从食物供应链、生产和加工单位或机构逐渐渗入到我们的家庭之中。紧张的现代生活方式令人倍感时间的紧迫,与10年前相比,消费者花费在家居清洁方面的时间要少得多。由于消费者看不见细菌,被细菌污染的区域通常得不到彻底清洁。在这种情况下,适当使用杀菌产品减少有害微生物可能造成的危险就显得很有用。在快节秦的生活方式里,人们越来越多地在晚上洗衣服,刚洗过的衣服潮湿且缺少阳光照射,衣物纤维中残余的人体汗液和油脂是细菌滋生的温床。因此,衣物洗涤剂和纤维柔顺剂中也应添加杀菌剂。与之类似,家居中的一些坚硬表面,如碗碟、厨房表面、浴室内湿的墙面以及坚固的室内地面等,都需要利用有效方法控制污染微生物的生长。主要阐述在家中保持良好卫生操作的必要性,并提出了在现代生活方式中面对这些前所未有的挑战所需的解决方法。     

Goal-directed fantasy, hypnotic susceptibility, and expectancies.

We conducted an initial screening session in which hypnosis was presented as a "test of imagination" and administered with other imagination measures. In a 2nd session, we instructed high- and low-hypnotizable Ss to imagine along with suggestions but to resist responding to motoric suggestions. Ss received either instructions to use goal-directed fantasies (GDFs) or no facilitative instructions. Sizable individual difference effects were secured. Hypnotizable Ss exhibited more suggestion-related movements and reported greater involuntariness than did low-hypnotizable Ss. With GDF instructions, low- and high-hypnotizable Ss reported equivalent GDF absorption and frequencies. However, hypnotizable Ss exhibited greater responsiveness and reported greater involuntariness than did those low in hypnotizability, even when their GDFs were equivalent. Thus, no support was generated for the hypotheses that sustained, elaborated suggestion-related imagery mediates response to suggestion or that absorption in suggestions is of particular importance for low-hypnotizable Ss. Findings support the hypothesis that expectancies mediate the relation between imagination, involuntariness, and responding. Hypnotizable imagining Ss exhibited greater responsiveness than a comparable sample of Ss did in a previous countersuggestion study (Lynn, Nash, Rhue, Frauman, & Stanley, 1983). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychobiological substrates of the Type A behavior pattern.

Argues that Type A (coronary prone) behavior may reflect excessive sympathetic responsiveness to environmental stressors rather than just person–situation interactions, and that an underlying biological or psychobiological factor might affect the expression of Type A behavior. Data consistent with a psychobiological view are provided by studies of (1) patients undergoing coronary bypass surgery and (2) the effects of beta-adrenergic blocking drugs in decreasing Type A behavior. A somatopsychic model of Type A behavior is formulated that considers the role of sympathetic nervous system responses and the processing of information about these responses in contributing to emotional behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self- and supervisory perspectives on age and work attitudes and performance.

Person- and context-oriented definitions of age were used to predict 3 sets of work outcomes: work attitudes, performance ratings, and reports of developmental practices. The 5 age measures included employee chronological age, employee subjective age (i.e., self-perceptions of age), and social age (i.e., others' perceptions of age), as well as self- and supervisors' perceptions of the employee's relative age (i.e., compared with the employee's work group). The study assessed (1) the relationships among the age measures, (2) the additive relationships among the age measures that predicted work outcomes, and (3) the interactive relationships among the age measures that predicted work outcomes. Each prediction received some support except for number (2). Furthermore, many of the age–work-outcome relationships were replicated in the managerial sample. Implications for the use of alternative age measures are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)