3,028 research outputs found
Spectroscopy from 2 to 200 keV
The astrophysical processes responsible for line and continuum emission in the spectra range 2 keV to 200 keV are examined from the viewpoint of designing a spectrometer which would operate in this regime. Phenomena considered include fluorescent line radiation in X-ray binaries, magnetically shifted iron lines and cyclotron emission from neutron star surfaces, line emission from cosmically abundant elements in thermal plasmas, and nuclear deexcitation lines in fresh nucleosynthetically produced matter. An instrument consisting of a approximately 10 sq cm array of planar germanium detectors surrounded by a large sodium-iodide anticoincidence shield is described and projected background rates and sensitivities are considered. A sample observing program for a two-day shuttle-based mission is included as an example of the wide range of scientific questions which could be addressed by such an instrument
Inequality and Procedural Justice in Social Dilemmas
This study investigates the influence of resource inequality and the fairness
of the allocation procedure of unequal resources on cooperative behavior in
social dilemmas. We propose a simple formal behavioral model that incorporates
conflicting selfish and social motivations. This model allows us to predict how
inequality influences cooperative behavior. Allocation of resources is manipulated
by three treatments that vary in terms of procedural justice: allocating resources
randomly, based on merit, and based on ascription. As predicted, procedural
justice influences cooperation significantly. Moreover, gender is found to be an
important factor interacting with the association between procedural justice and
cooperative behavior.
The Role of Canids in Ritual and Domestic Contexts: New Ancient DNA Insights from Complex Hunter-Gatherer Sites in Prehistoric Central California
This study explores the interrelationship between the genus Canis and hunter–gatherers through a case study of prehistoric Native Americans in the San Francisco Bay-Sacramento Delta area. A distinctive aspect of the region\u27s prehistoric record is the interment of canids, variously classified as coyotes, dogs, and wolves. Since these species are difficult to distinguish based solely on morphology, ancient DNA analysis was employed to distinguish species. The DNA study results, the first on canids from archaeological sites in California, are entirely represented by domesticated dogs (including both interments and disarticulated samples from midden deposits). These results, buttressed by stable isotope analyses, provide new insight into the complex interrelationship between humans and canids in both ritual and prosaic contexts, and reveal a more prominent role for dogs than previously envisioned
Understanding Minority Patients’ Beliefs About Hypertension to Reduce Gaps in Communication Between Patients and Clinicians
The authors’ objective was to gain a better understanding of minority patients’ beliefs about hypertension and to use this understanding to develop a model to explain gaps in communication between patients and clinicians. Eighty-eight hypertensive black and Latino adults from 4 inner-city primary care clinics participated in focus groups to elucidate views on hypertension. Participants believed that hypertension was a serious illness in need of treatment. Participants’ diverged from the medical model in their beliefs about the time-course of hypertension (believed hypertension was intermittent); causes of hypertension (believed stress, racism, pollution, and poverty were the important causes); symptoms of hypertension (believed hypertension was primarily present when symptomatic); and treatments for hypertension (preferred alternative treatments that reduced stress over prescription medications). Participants distrusted clinicians who prioritized medications that did not directly address their understanding of the causes or symptoms of hypertension. Patients’ models of understanding chronic asymptomatic illnesses such as hypertension challenge the legitimacy of lifelong, pill-centered treatment. Listening to patients’ beliefs about hypertension may increase trust, improve communication, and encourage better self-management of hypertension
Can illness beliefs, from the common-sense model, prospectively predict adherence to self-management behaviours?: a systematic review and meta-analysis
Objective: To determine whether people’s beliefs about their illness, conceptualised by the common sense model (CSM), can prospectively predict adherence to self-management behaviours (including, attendance, medication, diet and exercise) in adults with acute and chronic physical illnesses.
Design and Main Outcome Measures: Electronic databases were searched in September 2014, for papers specifying the use of the ‘CSM’ in relation to ‘self-management’, ‘rehabilitation’ and ‘adherence’ in the context of physical illness. Six hundred abstracts emerged. Data from 52 relevant studies were extracted. Twenty-one studies were meta-analysed, using correlation coefficients in random effects models. The remainder were descriptively synthesised.
Results: The effect sizes for individual illness belief domains and adherence to self-management behaviours ranged from .04 to .13, indicating very weak, predictive relationships. Further analysis revealed that predictive relationships did not differ by the: type of self-management behaviour; acute or chronic illness; or duration of follow-up.
Conclusion: Individual illness belief domains, outlined by the CSM, did not predict adherence to self-management behaviours in adults with physical illnesses. Prospective relationships, controlling for past behaviour, also did not emerge. Other factors, including patients’ treatment beliefs and inter-relationships between individual illness beliefs domains, may have influenced potential associations with adherence to self-management behaviours
A comparison of the illness beliefs of people with angina and their peers: a questionnaire study
BACKGROUND: What people believe about their illness may affect how they cope with it. It has been suggested that such beliefs stem from those commonly held within society . This study compared the beliefs held by people with angina, regarding causation and coping in angina, with the beliefs of their friends who do not suffer from angina. METHODS: Postal survey using the York Angina Beliefs Questionnaire (version 1), which elicits stress attributions and misconceived beliefs about causation and coping. This was administered to 164 people with angina and their non-cohabiting friends matched for age and sex. 132 people with angina and 94 friends completed the questionnaire. RESULTS: Peers are more likely than people with angina to believe that angina is caused by a worn out heart (p <0.01), angina is a small heart attack (p = 0.02), and that it causes permanent damage to the heart (p <0.001). Peers were also more likely to believe that people with angina should take life easy (p <0.01) and avoid exercise (p = 0.04) and excitement (p <0.01). CONCLUSIONS: The beliefs of the peer group about causation and coping in angina run counter to professional advice. Over time this may contribute to a reduction in patient concordance with risk factor reduction, and may help to create cardiac invalids
An interpretative phenomenological analysis of men’s and women’s coping strategy selection during early IVF treatment
Objectives: To describe the coping strategies that men and women adopted during the early stages of in vitro fertilisation treatment, and explore why and how they selected those strategies. Background: Previous research has identified coping strategies used during fertility treatment and the impact of those strategies on adjustment, but not how and why individuals choose the strategies they did, which is important for understanding coping strategy use as a self-regulatory process. Methods: Three heterosexual couples took part in two or three individual semi-structured interviews over six months, producing fourteen accounts, which were analysed using interpretative phenomenological analysis. Results: The emergent themes were: not dwelling on emotional issues; getting on with treatment; and keeping busy with other things. Participants selected coping strategies in a conscious, deliberate way, by making comparisons with other patients and by drawing on their broader, customary ways of coping. The strategies participants adopted made sense in the context of their long-term goals as well as their short-term treatment objectives. Conclusion: This research shows that for these participants, shorter-term behavioural strategies were informed by longer-term goals, which is consistent with a self-regulatory approach to understanding how people cope with the stress of treatment for infertility.N/
Characterizing Polytobacco Use Trajectories and Their Associations With Substance Use and Mental Health Across Mid-Adolescence.
Background:Polytobacco product use is suspected to be common, dynamic across time, and increase risk for adverse behavioral outcomes. We statistically modeled characteristic types of polytobacco use trajectories during mid-adolescence and tested their prospective association with substance use and mental health problems. Methods:Adolescents (N = 3393) in Los Angeles, CA, were surveyed semiannually from 9th to 11th grade. Past 6-month combustible cigarette, e-cigarette, or hookah use (yes/no) over four assessments were analyzed using parallel growth mixture modeling to identify a parsimonious set of polytobacco use trajectories. A tobacco product use trajectory group was used to predict substance use and mental health at the fifth assessment. Results:Three profiles were identified: (1) tobacco nonusers (N = 2291, 67.5%) with the lowest use prevalence (<3%) of all products across all timepoints; (2) polyproduct users (N = 920, 27.1%) with moderate use prevalence of each product (8-35%) that escalated for combustible cigarettes but decreased for e-cigarettes and hookah across time; and (3) chronic polyproduct users (N = 182, 5.4%) with high prevalence of each product use (38-86%) that escalated for combustible cigarettes and e-cigarettes. Nonusers, polyproduct users, and chronic polyproduct users reported successively higher alcohol, marijuana, and illicit drug use and ADHD at the final follow-up, respectively. Both tobacco using groups (vs. nonusers) reported greater odds of depression and anxiety at the final follow-up but did not differ from each other. Conclusions:Adolescent polytobacco use may involve a common moderate risk trajectory and a less common high-risk chronic trajectory. Both trajectories predict substance use and mental health symptomology. Implications:Variation in use and co-use of combustible cigarette, e-cigarette, and hookah use in mid-adolescence can be parsimoniously characterized by a small set common trajectory profiles in which polyproduct use are predominant patterns of tobacco product use, which predict adverse behavioral outcomes. Prevention and policy addressing polytobacco use (relative to single product use) may be optimal tobacco control strategies for youth, which may in turn prevent other forms of substance use and mental health problems
The experience of living with knee osteoarthritis: exploring illness and treatment beliefs through thematic analysis
Purpose: Knee osteoarthritis (OA) is a major cause of disability in older adults. However, there is limited research on the daily experience of living with knee OA. We aimed to offer insight into the beliefs of patients with knee OA about their illness and treatment.
Method: Twenty-four semi-structured interviews were conducted with 17 women and 7 men with physician-diagnosed knee OA, aged between 48 and 84 years (mean 1/4 62, SD 1/4 7). The audio-taped interviews lasted from 30 min to 1 h, and were transcribed verbatim. The data were subjected to thematic analysis. The transcripts were independently coded by two researchers to increase reliability of coding.
Results: Six themes were developed and two of these are examined in further detail: (i) Illness representation and (ii) Beliefs about the medical and surgical control of pain. Illness representation comprised beliefs about people’s understanding of OA and their pain experience, as well as expectations about the course of illness. The second theme presented experiences of limited pain relief and concerns about the use of drugs and surgery.
Conclusion: Exploring illness representations and beliefs about medical and surgical control of pain may provide the basis for initiating psychological interventions for people with knee OA
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