269 research outputs found

    The changing structure of a Ganda village

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    El desarrollo de los métodos del trabajo de campo en la antropología social

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    The Sloan Digital Sky Survey Reverberation Mapping Project: Ensemble Spectroscopic Variability of Quasar Broad Emission Lines

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    We explore the variability of quasars in the MgII and Hbeta broad emission lines and UV/optical continuum emission using the Sloan Digital Sky Survey Reverberation Mapping project (SDSS-RM). This is the largest spectroscopic study of quasar variability to date: our study includes 29 spectroscopic epochs from SDSS-RM over 66 months, containing 357 quasars with MgII and 41 quasars with Hbeta . On longer timescales, the study is also supplemented with two-epoch data from SDSS-I/II. The SDSS-I/II data include an additional 28542854 quasars with MgII and 572 quasars with Hbeta. The MgII emission line is significantly variable (Δf/f\Delta f/f 10% on 100-day timescales), a necessary prerequisite for its use for reverberation mapping studies. The data also confirm that continuum variability increases with timescale and decreases with luminosity, and the continuum light curves are consistent with a damped random-walk model on rest-frame timescales of ≳5\gtrsim 5 days. We compare the emission-line and continuum variability to investigate the structure of the broad-line region. Broad-line variability shows a shallower increase with timescale compared to the continuum emission, demonstrating that the broad-line transfer function is not a δ\delta-function. Hbeta is more variable than MgII (roughly by a factor of 1.51.5), suggesting different excitation mechanisms, optical depths and/or geometrical configuration for each emission line. The ensemble spectroscopic variability measurements enabled by the SDSS-RM project have important consequences for future studies of reverberation mapping and black hole mass estimation of 1<z<21<z<2 quasars.Comment: 20 pages, 25 figures. ApJ accepted: minor revisions following referee repor

    A Pilot Study on the Effects of Exercise on Depression Symptoms Using Levels of Neurotransmitters and EEG as Markers

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    Context: The prescribing of exercise by physicians has become a popular practice, yet the effectiveness of exercise on symptoms of depression is difficult to determine due to a lack of randomized controlled trials with clinical populations. Reports also indicate that only a small percentage of physicians advise their patients regarding exercise and confusion still exists as to how much and what types are best. Aims: To understand the mechanisms that make exercise a viable treatment in depression. Settings and Design: This study employed a six‑week, two group, single‑level trial, pre‑ and posttest design using self‑report of symptoms, blood levels of serotonin, dopamine, epinephrine, and norepinephrine, and frontal slow wave EEG activity as markers. This study was registered with clinicaltrials.gov. ID# NCT02023281. Subjects and Methods: Eleven participants with a diagnosis of depression between the ages of 18 and 65 were enrolled from March 2013 through May 2013. Baseline and post‑intervention measures consisted of the Beck Depression Inventory‑II, blood serum levels of serotonin, catecholamines (epinephrine, norepinephrine, and dopamine), and mean alpha frequency. Statistical Analysis Used: A series of independent t‑tests for each dependent variable was conducted. Results: Independent t‑tests reveal significant between‑group differences in depression scores (P = 0.005, d = 2.23); F7 activity (P = 0.012, d = 1.92); and F8 activity (P = 0.04, d = 1.52). Conclusions: The results of this pilot study show that even mild to very moderate levels of exercise 2‑3 times per week consisting of alternating days of aerobic and strength resistance training can be effective in reducing symptoms of depression giving physicians concrete information for their patients on the prescription of exercise

    The effects of changes to the built environment on the mental health and well-being of adults: Systematic review

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    © 2018 The Authors There is increasing interest in the influence of place on health, and the need to distinguish between environmental and individual level factors. For environmental-level factors, current evidence tends to show associations through cross-sectional and uncontrolled longitudinal analyses rather than through more robust study designs that can provide stronger causal evidence. We restricted this systematic review to randomised (or cluster) randomised controlled trials and controlled before-and-after studies of changes to the built environment. Date of search was December 2016. We identified 14 studies. No evidence was found of an effect on mental health from ‘urban regeneration’ and ‘improving green infrastructure’ studies. Beneficial effects on quality-of-life outcomes from ‘improving green infrastructure’ were found in two studies. One ‘improving green infrastructure’ study reported an improvement in social isolation. Risk-of-bias assessment indicated robust data from only four studies. Overall, evidence for the impact of built environment interventions on mental health and quality-of-life is weak. Future research requires more robust study designs and interdisciplinary research involving public health, planning and urban design experts

    Development and testing the feasibility of a sports-based mental health promotion intervention in Nepal: a protocol for a pilot cluster-randomised controlled trial

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    Background: Mental wellbeing encompasses life satisfaction, social connectedness, agency and resilience. In adolescence, mental wellbeing reduces sexual health risk behaviours, substance use and violence; improves educational outcomes; and protects mental health in adulthood. Mental health promotion seeks to improve mental wellbeing and can include activities to engage participants in sport. However, few high-quality trials of mental health promotion interventions have been conducted with adolescents, especially in low- and middle-income countries. We sought to address this gap by testing SMART (Sports-based Mental heAlth pRomotion for adolescenTs) in a pilot cluster-randomised controlled trial (cRCT) in Bardiya, Nepal. // Methods: The objectives of the trial are to assess the acceptability and feasibility of SMART, test trial procedures, explore outcome distributions in intervention and control clusters and calculate the total annual cost of the intervention and unit cost per adolescent. The trial design is a parallel-group, two-arm superiority pilot cRCT with a 1:1 allocation ratio and two cross-sectional census surveys with adolescents aged 12–19, one pre-intervention (baseline) and one post-intervention (endline). The study area is four communities of approximately 1000 population (166 adolescents per community). Each community represents one cluster. SMART comprises twice weekly football, martial arts and dance coaching, open to all adolescents in the community, led by local sports coaches who have received psychosocial training. Sports melas (festivals) and theatre performances will raise community awareness about SMART, mental health and the benefits of sport. Adolescents in control clusters will participate in sport as usual. In baseline and endline surveys, we will measure mental wellbeing, self-esteem, self-efficacy, emotion regulation, social support, depression, anxiety and functional impairment. Using observation checklists, unstructured observation and attendance registers from coaching sessions, and minutes of meetings between coaches and supervisors, we will assess intervention fidelity, exposure and reach. In focus group discussions and interviews with coaches, teachers, caregivers and adolescents, we will explore intervention acceptability and mechanisms of change. Intervention costs will be captured from monthly project accounts, timesheets and discussions with staff members. // Discussion: Findings will identify elements of the intervention and trial procedures requiring revision prior to a full cRCT to evaluate the effectiveness of SMART

    The Bottom Line: Investing for Impact on Economic Mobility in the U.S.

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    There is no greater challenge in the United States today than income inequality. It has been 50 years since the War on Poverty began. We have made progress but not enough. More than 32 million children live in low-income families, and racial and gender gaps persist. For the first time, Americans do not believe life will be better for the next generation. We have both a moral and an economic imperative to fuel social and economic mobility in this country.The Aspen Institute was founded in 1950 as a place to address the critical issues of our time. Today, ensuring that the American dream can be a possibility for all and be passed from one generation to the next is that issue. This commitment is at the heart of the work of many policy programs at the Aspen Institute. Ending the cycle of poverty requires leadership and hard work across all sectors, from nonprofit organizations, philanthropies, and academia to the government and private sector. This report recognizes the importance of learning from all sectors in tackling any challenge. Specifically, it builds on opportunities in the growing impact investment field. The report draws on the lessons from market-based approaches to identify tools and strategies that can help move the needle on family economic security. In this report, you will find the following: Case studies -- An opportunity to go under the hood on deals with the Bank of America, W.K. Kellogg Foundation, Acelero Learning, and others; Point of view essays -- Insights and lessons from leaders in the field; Deals at a glance -- Snapshots of impact investors and what they have learned, including the Kresge Foundation, Living Cities, and the MacArthur Foundation; and Survey results and lessons learned -- Trends among active and emerging players in the U.S. impact investment field and the lessons that can be applied to economic mobility in the U.S. We are pleased to offer this expanded perspective on impact investing in the U.S. and the lessons for investors, philanthropists, and non-profits working to build strong and prosperous families and communities
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