223 research outputs found

    A Complete Scheme of Ionization Cooling for a Muon Collider

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    A complete scheme for production and cooling a muon beam for three specified muon colliders is presented. Parameters for these muon colliders are given. The scheme starts with the front end of a proposed neutrino factory that yields bunch trains of both muon signs. Emittance exchange cooling in slow helical lattices reduces the longitudinal emittance until it becomes possible to merge the trains into single bunches, one of each sign. Further cooling in all dimensions is applied to the single bunches in further slow helical lattices. Final transverse cooling to the required parameters is achieved in 50 T solenoids using high Tc superconductor at 4 K. Preliminary simulations of each element are presented.Comment: 3 pages, 6 figure

    Relationship between children's cognitions and later educational progress in rural South Africa:A longitudinal study

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    Background: Children in low and middle-income countries (LMIC) who remain in school have better health and employment outcomes. South Africa, like many LMIC, has a secondary school completion rate under 50%, leaving room for improvement if we can identify factors that affect educational attainment. This is the first longitudinal study to examine the effects of childhood mental health and cognitions on educational outcomes in LMIC. Methods: Using the Strengths and Difficulties Questionnaire (SDQ) and Cognitive Triad Inventory for Children (CTI-C), we assessed the psychological functioning and cognition of children aged 10-12 in rural South Africa. We linked that data with measures of educational progress collected five years later and examined associations between educational progress and 1) behavioural and emotional problems and 2) cognitive interpretations, adjusting for possible confounders. Results: Educational data was available for 443 individuals. 92% (n= 408) of individuals had advanced three or fewer grades in seven years. Having more positive cognitions (CTIC-C) was positively associated with progressing at least three grade levels (adjusted OR: 1.43; 95% CI: 1.14-1.79). There was no evidence for an association between emotional and behavioural problems (SDQ) and educational progress (OR: 0.90; 95% CI: 0.72-1.11). Conclusion: If children in LMIC can develop more positive perspectives, they may be able to stay in school longer. Cognitions can be modified, and future studies should test interventions that work to improve cognition in childhood, guided , for example, by principles of cognitive behavioral therapy

    Obstacles and facilitators to communicating with children about their parents’ mental illness: A qualitative study in a sub-district of Mpumalanga, South Africa

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    Background Given that common mental disorders are one of the leading causes of disease burden worldwide, it is likely that many children are growing up with a parent or other adult within their family who has anxiety or depression. Parents with a mental illness may not consider it appropriate to discuss their illness with their child, and consequently an absence of communication may lead to stigmatization, shame, misunderstanding their parents’ symptoms, and even blaming themselves. There is a scarcity of research exploring the experiences and perceptions of healthcare professionals about communication with children of parents with mental illness in low-resource and African contexts. Methods A qualitative study using semi-structured interviews with healthcare professionals (n = 15) was conducted within the Bushbuckridge sub-district of Mpumalanga Province, South Africa. Data were analysed using Thematic Analysis. Results Four themes were identified relating to the obstacles around communication with children. These included: (1) finding an appropriate language to describe mental illness, as well as the prevailing cultural explanations of mental illness (2) the stigma associated with mental illness (3) the perceived role of children in society and (4) mental health services and staff skills. Two themes that addressed facilitators of communication about parental mental illness were identified: (1) the potential to increase mental health awareness amongst the broader community through social media, the internet, and general psychoeducation (2) healthcare professionals’ concerns for the wellbeing and future mental health of patients’ children, as well as their hopes for increased mental health awareness amongst future generations. Conclusions This study provides insight into healthcare professionals’ attitudes and perceptions about talking to patients and families within their community about mental illness. The results provide recommendations about possible ways to promote sharing information about a parent’s mental illness with children at an individual and community level. Future research should focus on the collaborative creation of culturally sensitive psychoeducational resources and evidence-based guidelines. This must be supported by systemic and organisational change in order for professionals to successfully facilitate conversations with patients who are parents, and their children

    Evaluation of record linkage of mortality data between a health and demographic surveillance system and national civil registration system in South Africa

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    Background: Health and Demographic Surveillance Systems (HDSS) collect independent mortality data that could be used for assessing the quality of mortality data in national civil registration (CR) systems in low- and middle-income countries. However, the use of HDSS data for such purposes depends on the quality of record linkage between the two data sources. We describe and evaluate the quality of record linkage between HDSS and CR mortality data in South Africa with HDSS data from Agincourt HDSS.Methods: We applied deterministic and probabilistic record linkage approaches to mortality records from 2006 to 2009 from the Agincourt HDSS and those in the CR system. Quality of the matches generated by the probabilistic approach was evaluated using sensitivity and positive predictive value (PPV) calculated from a subset of records that were linked using national identity number. Matched and unmatched records from the Agincourt HDSS were compared to identify characteristics associated with successful matching. In addition, the distribution of background characteristics in all deaths that occurred in 2009 and those linked to CR records was compared to assess systematic bias in the resulting record-linked dataset in the latest time period.Results: Deterministic and probabilistic record linkage approaches combined linked a total of 2264 out of 3726 (60.8%) mortality records from the Agincourt HDSS to those in the CR system. Probabilistic approaches independently linked 1969 (87.0%) of the linked records. In a subset of 708 records that were linked using national identity number, the probabilistic approaches yielded sensitivity of 90.0% and PPV of 98.5%. Records belonging to more vulnerable people, including poorer persons, young children, and non-South Africans were less likely to be matched. Nevertheless, distribution of most background characteristics was similar between all Agincourt HDSS deaths and those matched to CR records in the latest time period.Conclusion: This study shows that record linkage of mortality data from HDSS and CR systems is possible and can be useful in South Africa. The study identifies predictors for death registration and data items and registration system characteristics that could be improved to achieve more optimal future matching possibilities

    The adolescent HIV executive function and drumming (AHEAD) study, a feasibility trial of a group drumming intervention amongst adolescents with HIV

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    AHEAD feasibility trial assessed the feasibility and acceptability of an 8-session group drummingprogramme aiming to improve executive function, depression and anxiety symptoms, andperceived social support in adolescents living with HIV in a rural low-income South Africansetting. Sixty-eight 12- to 19-year-old adolescents participated. They were individuallyrandomised. The intervention arm (n= 34) received weekly hour-long group drumming sessions.Controls (n= 34) received no intervention. Feasibility and acceptability were assessed usingrates of: enrolment; retention; attendance; logistical problems; adolescent-reportedacceptability. Secondary measures included:five Oxford Cognitive Screen-Executive Function(OCS-EF) tasks; two Rapid Assessment of Cognitive and Emotional Regulation (RACER) tasks; theSelf-Reporting Questionnaire-20 (SRQ-20) measuring depression and anxiety symptoms; theMultidimensional Scale of Perceived Social Support (MSPSS). All feasibility criteria were withingreen progression limits. Enrolment, retention, and acceptability were high. There was a positive effect on adolescent depressed mood with a signal for a working memory effect. There were no significant effects on executive function or socio-emotional scales. Qualitative findings suggested socio-emotional benefits including group belonging; decreased internalised stigma; improved mood; and decreased anxiety. Group drumming is a feasible and acceptable intervention among adolescents living with HIV in rural South Africa. A full-scale trial is recommendedAfrica-Oxford Initiative (AfiOx-32), the Society for Education, Music and Psychology Research (SEMPRE) Gerry Farrell scholarship, the Murray Speight grant, the Rhodes Trust, and the Medical Research Council United Kingdom.https://www.tandfonline.com/loi/caic20Musi

    Depression and incident HIV in adolescent girls and young women in HPTN 068:Targets for prevention and mediating factors

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    Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2019. This work is written by (a) US Government employee(s) and is in the public domain in the US. The human immunodeficiency virus (HIV) epidemic among adolescent girls and young women (AGYW) in sub-Saharan Africa is a critical public health problem. We assessed whether depressive symptoms in AGYW were longitudinally associated with incident HIV, and identified potential social and behavioral mediators. Data came from a randomized trial of a cash transfer conditional on school attendance among AGYW (ages 13-21 years) in rural Mpumalanga Province, South Africa, during 2011-2017. We estimated the relationship between depressive symptoms and cumulative HIV incidence using a linear probability model, and we assessed mediation using inverse odds ratio weighting. Inference was calculated using the nonparametric bootstrap. AGYW with depressive symptoms had higher cumulative incidence of HIV compared with those without (risk difference = 3.5, 95% confidence interval (CI): 0.1, 7.0). The strongest individual mediators of this association were parental monitoring and involvement (indirect effect = 1.6, 95% CI: 0.0, 3.3) and reporting a partner would hit her if she asked him to wear a condom (indirect effect = 1.5, 95% CI: -0.3, 3.3). All mediators jointly explained two-thirds (indirect effect = 2.4, 95% CI: 0.2, 4.5) of the association between depressive symptoms and HIV incidence. Interventions addressing mental health might reduce risk of acquiring HIV among AGYW

    Figuring Rhetoric: From Antistrophe to Apostrophe through Catastrophe

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    This essay explores rhetoric tropologically through various strophes: antistrophe, catastrophe, and apostrophe. Our purpose is to delineate problems and possibilities that these tropes pose for rhetoric in an effort to create new rhetorics. We seek to display the antistrophic and catastrophic figurations of rhetoric and then use visual lenses of photography and cinema to disrupt the figurations. Following the disruption, we seek to heighten sensibilities to other figurations, in particular an apostrophic figuration. We cast apostrophe as a figure for change because it marks a deeply felt turn toward difference and otherness. Turned as such, rhetoric becomes erotic

    LSST Science Book, Version 2.0

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    A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo
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