Stochastic Games, Oligopoly Theory and Competitive Resource Allocation

We define discrete time sequential games which are multiperson Markov decision processes. The extant theory is sketched and compared with our assessment of research needs in dynamic models of oligopoly and other competitive resource allocation problems. A special class of economic survival games is noted

Ingenuous interpretation of elevated blood levels of macromolecular markers of myocardial injury: a recipe for confusion

AbstractSeveral assumptions about elevations of macromolecular markers of myocardial injury in blood require critical consideration. The dichotomy of modest, persistent elevations of troponins I and T as prognostic factors in patients with unstable angina and absent elevations of isoenzymes of creatine kinase is presently unexplained. Factors influencing the appearance of macromolecular markers of myocardial injury in blood are considered, including the need to estimate baseline values, to consider elevations as deviations from baseline rather than simply points within a distribution of baseline values in normal subjects, to recognize operative biochemical and physiologic determinants of marker release from injured myocytes and washout and to take into account the influence of apoptosis. Elucidation and consideration of mechanisms underlying the appearance of specific macromolecular markers in blood appear likely to improve diagnosis and explain the prognostic power of the troponins in patients with unstable angina. Detection of proteolytic breakdown products of troponins in blood is likely to explain the modest, persistent elevations seen in some patients with unstable angina and their prognostic implications

Noise Induced Hearing Loss in Children: Preventing the Silent Epidemic

Noise-induced hearing loss and related tinnitus are often unrecognized problems, especially in non-occupational settings. Research indicates that increasing numbers of children and adolescents have or are acquiring noise induced hearing losses. Noise induced hearing loss can almost completely be prevented with simple precautionary measures. Educational programs rarely exist outside of those mandated in occupational settings. Health Communication theory can be applied to hearing health for developing effective loss prevention programs. Dangerous Decibels is one example of an effective multi-disciplinary effort to develop and disseminated prevention strategies

Some Ranking and Selection Criteria for Determining Sample Sizes in Two Different Models for a Drug Combination Problem

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Stochastic Games, Oligopoly Theory and Competitive Resource Allocation

We define discrete time sequential games which are multiperson Markov decision processes. The extant theory is sketched and compared with our assessment of research needs in dynamic models of oligopoly and other competitive resource allocation problems. A special class of economic survival games is noted.

Lactobacillus acidophilus Contributes to a Healthy Environment for Vaginal Epithelial Cells

Lactobacillus species in the female genital tract are thought to act as a barrier to infection. Several studies have demonstrated that lactobacilli can adhere to vaginal epithelial cells. However, little is known about how the adherence of lactobacilli to vaginal epithelial cells affects the acidity, cell viability, or proliferation of the lactobacilli themselves or those of vaginal epithelial cells. Lactobacillus acidophilus was co-cultured with immortalized human vaginal epithelial cells (MS74 cell line), and the growth of L. acidophilus and the acidity of the culture medium were measured. MS74 cell density and viability were also assessed by counting cell numbers and observing the cell attachment state. L. acidophilus showed exponential growth for the first 6 hr until 9 hr, and the pH was maintained close to 4.0-5.0 at 24 hr after culture, consistent with previous studies. The growth curve of L. acidophilus or the pH values were relatively unaffected by co-culture with MS74 cells, confirming that L. acidophilus maintains a low pH in the presence of MS74 cells. This co-culture model could therefore potentially be used to mimic vaginal conditions for future in vitro studies. On the other hand, MS74 cells co-cultured with L. acidophilus more firmly attached to the culture plate, and a higher number of cells were present compared to cells cultured in the absence of L. acidophilus. These results indicate that L. acidophilus increases MS74 cell proliferation and viability, suggesting that lactobacilli may contribute to the healthy environment for vaginal epithelial cells

Direct and indirect effects of mood on risk decision making in safety-critical workers

The study aimed to examine the direct influence of specific moods (fatigue, anxiety, happiness) on risk in safety-critical decision making. It further aimed to explore indirect effects, specifically, the potential mediating effects of information processing assessed using a goodness-of-simulation task. Trait fatigue and anxiety were associated with an increase in risk taking on the Safety-Critical Personal Risk Inventory (S-CPRI), however the effect of fatigue was partialled out by anxiety. Trait happiness, in contrast was related to less risky decision making. Findings concerning the ability to simulate suggest that better simulators made less risky decisions. Anxious workers were generally less able to simulate. It is suggested that in this safety-critical environment happiness had a direct effect on risk decision making while the effect of trait anxiety was mediated by goodness-of-simulation

Reciprocity networks and the participation problem

Reciprocity can be a powerful motivation for human behaviour. Scholars have argued that it is relevant in the context of private provision of public goods. We examine whether reciprocity can resolve the associated coordination problem. The interaction of reciprocity with cost-sharing is critical. Neither cost-sharing nor reciprocity in isolation can solve the problem, but together they have that potential. We introduce new network notions of reciprocity relations to better understand this

Negative affect and ruminative self-focus during everyday goal pursuit

Models of self-regulation propose that negative affect is generated when progress towards goals is perceived to be inadequate. Similarly, ruminative thinking is hypothesised to be triggered by unattained goals (Martin & Tesser, 1996). We conducted an experience-sampling study in which participants recorded their negative affect, ruminative self-focus, and goal appraisals eight times daily for one week. Negative affect and ruminative self-focus were each associated with low levels of goal success and (with the exception of sadness) high levels of goal importance. As predicted, the combination of low goal success and high goal importance was associated with the highest levels of negative affect, and this interaction was marginally significant for ruminative self-focus. Decomposition of the ruminative self-focus measure revealed that the success by importance interaction was significantly associated with focus on problems but not focus on feelings. Findings did not differ for individuals reporting high versus low levels of depressive symptoms or trait rumination. These results suggest that self-regulatory models of goal pursuit provide a useful explanatory framework for the study of affect and ruminative thinking in everyday life

An intervention modelling experiment to change GP's intentions to implement evidence-based practice : using theory-based interventions to promote GP management of upper respiratory tract infection without prescribing antibiotics #2

Background: Psychological theories of behaviour may provide a framework to guide the design of interventions to change professional behaviour. Behaviour change interventions, designed using psychological theory and targeting important motivational beliefs, were experimentally evaluated for effects on the behavioural intention and simulated behaviour of GPs in the management of uncomplicated upper respiratory tract infection (URTI). Methods: The design was a 2 × 2 factorial randomised controlled trial. A postal questionnaire was developed based on three theories of human behaviour: Theory of Planned Behaviour; Social Cognitive Theory and Operant Learning Theory. The beliefs and attitudes of GPs regarding the management of URTI without antibiotics and rates of prescribing on eight patient scenarios were measured at baseline and post-intervention. Two theory-based interventions, a "graded task" with "action planning" and a "persuasive communication", were incorporated into the post-intervention questionnaire. Trial groups were compared using co-variate analyses. Results: Post-intervention questionnaires were returned for 340/397 (86%) GPs who responded to the baseline survey. Each intervention had a significant effect on its targeted behavioural belief: compared to those not receiving the intervention GPs completing Intervention 1 reported stronger self-efficacy scores (Beta = 1.41, 95% CI: 0.64 to 2.25) and GPs completing Intervention 2 had more positive anticipated consequences scores (Beta = 0.98, 95% CI = 0.46 to 1.98). Intervention 2 had a significant effect on intention (Beta = 0.90, 95% CI = 0.41 to 1.38) and simulated behaviour (Beta = 0.47, 95% CI = 0.19 to 0.74). Conclusion: GPs' intended management of URTI was significantly influenced by their confidence in their ability to manage URTI without antibiotics and the consequences they anticipated as a result of doing so. Two targeted behaviour change interventions differentially affected these beliefs. One intervention also significantly enhanced GPs' intentions not to prescribe antibiotics for URTI and resulted in lower rates of prescribing on patient scenarios compared to a control group. The theoretical frameworks utilised provide a scientific rationale for understanding how and why the interventions had these effects, improving the reproducibility and generalisability of these findings and offering a sound basis for an intervention in a "real world" trial. Trial registration: Clinicaltrials.gov NCT00376142This study is funded by the European Commission Research Directorate as part of a multi-partner program: Research Based Education and Quality Improvement (ReBEQI): A Framework and tools to develop effective quality improvement programs in European healthcare. (Proposal No: QLRT-2001-00657)