331 research outputs found
Tuning of Human Modulation Filters Is Carrier-Frequency Dependent
Licensed under the Creative Commons Attribution License
The Emergence of HIV Transmitted Resistance in Botswana: âWhen Will the WHO Detection Threshold Be Exceeded?â
BACKGROUND: The Botswana antiretroviral program began in 2002 and currently treats 42,000 patients, with a goal of treating 85,000 by 2009. The World Health Organization (WHO) has begun to implement a surveillance system for detecting transmitted resistance that exceeds a threshold of 5%. However, the WHO has not determined when this threshold will be reached. Here we model the Botswana government's treatment plan and predict, to 2009, the likely stochastic evolution of transmitted resistance. METHODS: We developed a model of the stochastic evolution of drug-resistant strains and formulated a birth-death Master equation. We analyzed this equation to obtain an analytical solution of the probabilistic evolutionary trajectory for transmitted resistance, and used treatment and demographic data from Botswana. We determined the temporal dynamics of transmitted resistance as a function of: (i) the transmissibility (i.e., fitness) of the drug-resistant strains that may evolve and (ii) the rate of acquired resistance. RESULTS: Transmitted resistance in Botswana will be unlikely to exceed the WHO's threshold by 2009 even if the rate of acquired resistance is high and the strains that evolve are half as fit as the wild-type strains. However, we also found that transmission of drug-resistant strains in Botswana could increase to âŒ15% by 2009 if the drug-resistant strains that evolve are as fit as the wild-type strains. CONCLUSIONS: Transmitted resistance will only be detected by the WHO (by 2009) if the strains that evolve are extremely fit and acquired resistance is high. Initially after a treatment program is begun a threshold lower than 5% should be used; and we advise that predictions should be made before setting a threshold. Our results indicate that it may be several years before the WHO's surveillance system is likely to detect transmitted resistance in other resource-poor countries that have significantly less ambitious treatment programs than Botswana
Creationism and Intelligent Design
Until recently, little attention has been paid in the school classroom to creationism and almost none to intelligent design. However, creationism and intelligent design appear to be on the increase and there are indications that there are more countries in which schools are becoming battlegrounds over them. I begin by examining whether creationism and intelligent design are controversial issues, drawing on Robert Deardenâs epistemic criterion of the controversial and more recent responses to and defences of this. I then examine whether the notion of âworldviewsâ in the context of creationism is a useful one by considering the film March of the Penguins. I conclude that the âworldviewsâ perspective on creationism is useful for two reasons: first, it indicates the difficulty of using the criterion of reason to decide whether an issue is controversial or not; secondly, it suggests that standard ways of addressing the diversity of student views in a science classroom may be inadequate. I close by examining the implications of this view for teaching in science lessons and elsewhere, for example in religious education lessons and at primary level where subject divisions cannot be made in so clear-cut a manner
âNothing about us without usâ : disabled people determining their human rights through the UNCRPD
The human rights and fundamental freedoms of disabled persons are set out in the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD). This paper firstly focuses on the importance of the involvement of disabled people at all levels of decision-making. The second part of the paper identifies those aspects of the UNCRPD that reflect the direct involvement of disabled people. Finally, it considers how human rights bodies can best build on this specific aspect of the UNCRPD in order to realize the potential of the Convention as a determining factor in affirming disabled people rights in an effective and meaningful manner.peer-reviewe
How does one become spiritual? The Spiritual Modeling Inventory of Life Environments (SMILE)
We report psychometric properties, correlates and underlying theory of the Spiritual Modeling Index of Life Environments (SMILE), a measure of perceptions of spiritual models, defined as everyday and prominent people who have functioned for respondents as exemplars of spiritual qualities, such as compassion, self-control, or faith. Demographic, spiritual, and personality correlates were examined in an ethnically diverse sample of college students from California, Connecticut, and Tennessee (N=1010). A summary measure of model influence was constructed from perceived models within family, school, religious organization, and among prominent individuals from both tradition and media. The SMILE, based on concepts from Bandura\u27s (1986) Social Cognitive Theory, was well-received by respondents. The summary measure demonstrated good 7-week test/retest reliability (r=.83); patterns of correlation supporting convergent, divergent, and criterion-related validity; demographic differences in expected directions; and substantial individual heterogeneity. Implications are discussed for further research and for pastoral, educational, and health-focused interventions
A Qualitative Exploration of Factors Affecting Group Cohesion and Team Play in Multiplayer Online Battle Arenas (MOBAs)
Previous research examining the social psychology of video-gaming has tended to focus on Massively Multiplayer Online Role Playing Game (MMORPG) environments, such as World of Warcraft. Although many online group processes have been examined using this game, this genre does not enforce cooperative play and studies tend to be based on very large groups. Newer genres are being developed and played which have so far not been studied. The genre known as Multiplayer Online Battle Arenas (MOBAs) are attracting large numbers of players and success depends on effective team playing within smaller groups. The study reported here explores team play within MOBAs. Due to the lack of literature examining this genre, Corbin and Straussâ (2008) Grounded Theory was used to analyse participantsâ subjective experiences of playing MOBAs to create a conceptual model. A focus group pilot study informed the development of questions and then semi-structured interviews took place with twelve participants; 1 female and 11 male students aged between 18-21 years. Participants were required to have recent and frequent MOBA exposure, but with different preferences regarding roles and experience. Data was analysed using open, axial and selective coding and the resulting model depicts a scale, as optimal team performance was linked to a balance between factors. The core category âCommunicationâ was heavily influenced by the relationship between teammates (friends or strangers). The balance of âCommunicationâ affected the balance of the final three categories: âTeam Compositionâ, âPsychological Stateâ and âLevel of Playâ. The conceptual model is critically linked with traditional group processes, such as Belbinâs (1993) team roles, Tuckmanâs (1965) model of group development and the perceptions and behaviour during the state of deindividuation (Taylor & MacDonald, 2002). The model has real-world application in both social and professional virtual environments, whilst contributing more broadly to research in Cyberpsychology and Social Psychology. Further research is suggested which will test predictions based on a predictive model
G protein-coupled receptor-mediated calcium signaling in astrocytes
Astrocytes express a large variety of G~protein-coupled receptors (GPCRs)
which mediate the transduction of extracellular signals into intracellular
calcium responses. This transduction is provided by a complex network of
biochemical reactions which mobilizes a wealth of possible calcium-mobilizing
second messenger molecules. Inositol 1,4,5-trisphosphate is probably the best
known of these molecules whose enzymes for its production and degradation are
nonetheless calcium-dependent. We present a biophysical modeling approach based
on the assumption of Michaelis-Menten enzyme kinetics, to effectively describe
GPCR-mediated astrocytic calcium signals. Our model is then used to study
different mechanisms at play in stimulus encoding by shape and frequency of
calcium oscillations in astrocytes.Comment: 35 pages, 6 figures, 1 table, 3 appendices (book chapter
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