699 research outputs found
Criminal Defectors Lead to the Emergence of Cooperation in an Experimental, Adversarial Game
While the evolution of cooperation has been widely studied, little attention has been devoted to adversarial settings wherein one actor can directly harm another. Recent theoretical work addresses this issue, introducing an adversarial game in which the emergence of cooperation is heavily reliant on the presence of āInformants,ā actors who defect at first-order by harming others, but who cooperate at second-order by punishing other defectors. We experimentally study this adversarial environment in the laboratory with human subjects to test whether Informants are indeed critical for the emergence of cooperation. We find in these experiments that, even more so than predicted by theory, Informants are crucial for the emergence and sustenance of a high cooperation state. A key lesson is that successfully reaching and maintaining a low defection society may require the cultivation of criminals who will also aid in the punishment of others
Implementation of Triple P-Positive Parenting Program in Hong Kong: Predictors of programme completion and clinical outcomes
This study examined the effectiveness of the Triple P-Positive Parenting Program in a government child health service delivery context with Chinese parents in Hong Kong. Specifically, the study sought to identify pre-intervention variables that might predict programme outcomes such as, level of clinical improvement and programme completion. Participants were 661 parents of pre-school and primary aged children participating in a group version of the Triple P-Positive Parenting Program. There were significant decreases in disruptive child behaviours, levels of parenting stress, general stress and anxiety and an increase in parenting sense of competence. Greater change in reports of child behaviour problems was related to lower levels of family income, new immigrant family status, and higher pre-intervention levels of parenting stress. The present study provides a profile of parents who are most likely to benefit from parent training programmes
Use of routinely collected health data in randomised clinical trials: comparison of trial-specific death data in the BOSS trial with NHS Digital data
Background:
A promising approach to reduce the increasing costs of clinical trials is the use of routinely collected health data as participant data. However, the quality of this data could limit its usability as trial participant data.
Methods:
The BOSS trial is a randomised controlled trial comparing regular endoscopies versus endoscopies at need in patients with Barrettās oesophagus with primary endpoint death. Data on death and cancer collected every 2 years after randomisation (trial-specific data) were compared to data received annually (all patients on one date) from the routinely collected health data source National Health Service (NHS) Digital. We investigated completeness, agreement and timeliness and looked at the implications for the primary trial outcome. Completeness and agreement were assessed by evaluating the number of reported and missing cases and any disparities between reported dates. Timeliness was considered by graphing the year a death was first reported in the trial-specific data against that for NHS Digital data. Implications on the primary trial outcome, overall survival, of using one of the data sources alone were investigated using Kaplan-Meier graphs. To assess the utility of cause of death and cancer diagnoses, oesophageal cancer cases were compared.
Results:
NHS Digital datasets included more deaths and often reported them sooner than the trial-specific data. The number reported as being from oesophageal cancer was similar in both datasets. Due to time lag in reporting and missing cases, the event rate appeared higher using the NHS Digital data.
Conclusion:
NHS Digital death data is useful for calculating overall survival where trial-specific follow-up is only every 2 years from randomisation and the follow-up requires patient response. The cancer data was not a large enough sample to assess usability. We suggest that this assessment of registry data is done for more phase III RCTs and for more registry data to get a more complete picture of when RCHD would be useful in phase III RCT.
Trial registration:
ISRCTN54190466 (BOSS) 1 Oct 2009
Predictors of Change Following Cognitive-Behavioral Treatment of Children with Anxiety Problems: A Preliminary Investigation on Negative Automatic Thoughts and Anxiety Control
The purpose of the present study was to evaluate negative automatic thoughts and anxiety control as predictors of change produced by cognitive-behavioral treatment of youths with anxiety disorders. Forty-five high-anxious children aged between 9 and 12Ā years who were selected from the primary school population, received a standardized CBT intervention that was provided in a group format. Before and after the intervention, children completed scales of negative automatic thoughts and perceived control over anxiety-related events as well as a questionnaire for measuring DSM-defined anxiety disorders symptoms, which was the outcome measure. Results indicated that CBT was effective in reducing childrenās anxiety symptoms. Most importantly, the reduction of anxiety disorders symptoms was significantly associated with a decrease in negative automatic thoughts and an increase of anxiety control, which provides support for the notion that these variables are candidate mediators of CBT in anxious youths
Social research on neglected diseases of poverty: Continuing and emerging themes
Copyright: Ā© 2009 Manderson et al.Neglected tropical diseases (NTDs) exist and persist for social and economic reasons that enable the vectors and pathogens to take advantage of changes in the behavioral and physical environment. Persistent poverty at household, community, and national levels, and inequalities within and between sectors, contribute to the perpetuation and re-emergence of NTDs. Changes in production and habitat affect the physical environment, so that agricultural development, mining and forestry, rapid industrialization, and urbanization all result in changes in human uses of the environment, exposure to vectors, and vulnerability to infection. Concurrently, political instability and lack of resources limit the capacity of governments to manage environments, control disease transmission, and ensure an effective health system. Social, cultural, economic, and political factors interact and influence government capacity and individual willingness to reduce the risks of infection and transmission, and to recognize and treat disease. Understanding the dynamic interaction of diverse factors in varying contexts is a complex task, yet critical for successful health promotion, disease prevention, and disease control. Many of the research techniques and tools needed for this purpose are available in the applied social sciences. In this article we use this term broadly, and so include behavioral, population and economic social sciences, social and cultural epidemiology, and the multiple disciplines of public health, health services, and health policy and planning. These latter fields, informed by foundational social science theory and methods, include health promotion, health communication, and heath education
Alpha-particle-induced complex chromosome exchanges transmitted through extra-thymic lymphopoiesis in vitro show evidence of emerging genomic instability
Human exposure to high-linear energy transfer Ī±-particles includes environmental (e.g. radon gas and its decay progeny), medical (e.g. radiopharmaceuticals) and occupational (nuclear industry) sources. The associated health risks of Ī±-particle exposure for lung cancer are well documented however the risk estimates for leukaemia remain uncertain. To further our understanding of Ī±-particle effects in target cells for leukaemogenesis and also to seek general markers of individual exposure to Ī±-particles, this study assessed the transmission of chromosomal damage initially-induced in human haemopoietic stem and progenitor cells after exposure to high-LET Ī±-particles. Cells surviving exposure were differentiated into mature T-cells by extra-thymic T-cell differentiation in vitro. Multiplex fluorescence in situ hybridisation (M-FISH) analysis of naĆÆve T-cell populations showed the occurrence of stable (clonal) complex chromosome aberrations consistent with those that are characteristically induced in spherical cells by the traversal of a single Ī±-particle track. Additionally, complex chromosome exchanges were observed in the progeny of irradiated mature T-cell populations. In addition to this, newly arising de novo chromosome aberrations were detected in cells which possessed clonal markers of Ī±-particle exposure and also in cells which did not show any evidence of previous exposure, suggesting ongoing genomic instability in these populations. Our findings support the usefulness and reliability of employing complex chromosome exchanges as indicators of past or ongoing exposure to high-LET radiation and demonstrate the potential applicability to evaluate health risks associated with Ī±-particle exposure.This work was supported by the Department of Health, UK. Contract RRX95 (RMA NSDTG)
The evolution of rotating stars
First, we review the main physical effects to be considered in the building
of evolutionary models of rotating stars on the Upper Main-Sequence (MS). The
internal rotation law evolves as a result of contraction and expansion,
meridional circulation, diffusion processes and mass loss. In turn,
differential rotation and mixing exert a feedback on circulation and diffusion,
so that a consistent treatment is necessary.
We review recent results on the evolution of internal rotation and the
surface rotational velocities for stars on the Upper MS, for red giants,
supergiants and W-R stars. A fast rotation is enhancing the mass loss by
stellar winds and reciprocally high mass loss is removing a lot of angular
momentum. The problem of the ``break-up'' or -limit is critically
examined in connection with the origin of Be and LBV stars. The effects of
rotation on the tracks in the HR diagram, the lifetimes, the isochrones, the
blue to red supergiant ratios, the formation of W-R stars, the chemical
abundances in massive stars as well as in red giants and AGB stars, are
reviewed in relation to recent observations for stars in the Galaxy and
Magellanic Clouds. The effects of rotation on the final stages and on the
chemical yields are examined, as well as the constraints placed by the periods
of pulsars. On the whole, this review points out that stellar evolution is not
only a function of mass M and metallicity Z, but of angular velocity
as well.Comment: 78 pages, 7 figures, review for Annual Review of Astronomy and
Astrophysics, vol. 38 (2000
Climate impacts of energy technologies depend on emissions timing
Energy technologies emit greenhouse gases with differing radiative efficiencies and atmospheric lifetimes. Standard practice for evaluating technologies, which uses the global warming potential (GWP) to compare the integrated radiative forcing of emitted gases over a fixed time horizon, does not acknowledge the importance of a changing background climate relative to climate change mitigation targets. Here we demonstrate that the GWP misvalues the impact of CH[subscript 4]-emitting technologies as mid-century approaches, and we propose a new class of metrics to evaluate technologies based on their time of use. The instantaneous climate impact (ICI) compares gases in an expected radiative forcing stabilization year, and the cumulative climate impact (CCI) compares their time-integrated radiative forcing up to a stabilization year. Using these dynamic metrics, we quantify the climate impacts of technologies and show that high-CH[subscript 4]-emitting energy sources become less advantageous over time. The impact of natural gas for transportation, with CH[subscript 4] leakage, exceeds that of gasoline within 1ā2 decades for a commonly cited 3 W m[superscript ā2] stabilization target. The impact of algae biodiesel overtakes that of corn ethanol within 2ā3 decades, where algae co-products are used to produce biogas and corn co-products are used for animal feed. The proposed metrics capture the changing importance of CH[subscript 4] emissions as a climate threshold is approached, thereby addressing a major shortcoming of the GWP for technology evaluation.New England University Transportation Center (DOT Grant DTRT07-G-0001
Cost-Effectiveness Analysis of Natriuretic Peptide Testing and Specialist Management in Patients with Suspected Acute Heart Failure
Objectives: To determine the cost-effectiveness of natriuretic peptide (NP) testing and specialist outreach in patients with acute heart failure (AHF) residing off the cardiology ward. Methods: We used a Markov model to estimate costs and quality-adjusted life-years (QALYs) for patients presenting to hospital with suspected AHF. We examined diagnostic workup with and without the NP test in suspected new cases, and we examined the impact of specialist heart failure outreach in all suspected cases. Inputs for the model were derived from systematic reviews, the UK national heart failure audit, randomized controlled trials, expert consensus from a National Institute for Health and Care Excellence guideline development group, and a national online survey. The main benefit from specialist care (cardiology ward and specialist outreach) was the increased likelihood of discharge on disease-modifying drugs for people with left ventricular systolic dysfunction, which improve mortality and reduce re-admissions due to worsened heart failure (associated with lower utility). Costs included diagnostic investigations, admissions, pharmacological therapy, and follow-up heart failure care. Results: NP testing and specialist outreach are both higher cost, higher QALY, cost-effective strategies (incremental cost-effectiveness ratios of Ā£11,656 and Ā£2,883 per QALY gained, respectively). Combining NP and specialist outreach is the most cost-effective strategy. This result was robust to both univariate deterministic and probabilistic sensitivity analyses. Conclusions: NP testing for the diagnostic workup of new suspected AHF is cost-effective. The use of specialist heart failure outreach for inpatients with AHF residing off the cardiology ward is cost-effective. Both interventions will help improve outcomes for this high-risk group
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