2,432 research outputs found
Tests of sunspot number sequences: 1. Using ionosonde data
More than 70 years ago it was recognised that ionospheric F2-layer critical frequencies [foF2] had a strong relationship to sunspot number. Using historic datasets from the Slough and Washington ionosondes, we evaluate the best statistical fits of foF2 to sunspot numbers (at each Universal Time [UT] separately) in order to search for drifts and abrupt changes in the fit residuals over Solar Cycles 17-21. This test is carried out for the original composite of the Wolf/ZĂŒrich/International sunspot number [R], the new âbackboneâ group sunspot number [RBB] and the proposed âcorrected sunspot numberâ [RC]. Polynomial fits are made both with and without allowance for the white-light facular area, which has been reported as being associated with cycle-to-cycle changes in the sunspot number - foF2 relationship. Over the interval studied here, R, RBB, and RC largely differ in their allowance for the âWaldmeier discontinuityâ around 1945 (the correction factor for which for R, RBB and RC is, respectively, zero, effectively over 20 %, and explicitly 11.6 %). It is shown that for Solar Cycles 18-21, all three sunspot data sequences perform well, but that the fit residuals are lowest and most uniform for RBB. We here use foF2 for those UTs for which R, RBB, and RC all give correlations exceeding 0.99 for intervals both before and after the Waldmeier discontinuity. The error introduced by the Waldmeier discontinuity causes R to underestimate the fitted values based on the foF2 data for 1932-1945 but RBB overestimates them by almost the same factor, implying that the correction for the Waldmeier discontinuity inherent in RBB is too large by a factor of two. Fit residuals are smallest and most uniform for RC and the ionospheric data support the optimum discontinuity multiplicative correction factor derived from the independent Royal Greenwich Observatory (RGO) sunspot group data for the same interval
Toward a Consensus on Guiding Principles for Health Systems Strengthening
Based upon a review of the literature, Robert Chad Swanson and colleagues present a set of guiding principles for health systems strengthening
Generation and characterisation of Friedreich ataxia YG8R mouse fibroblast and neural stem cell models
This article has been made available through the Brunel Open Access Publishing Fund.Background: Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by GAA repeat expansion in the first intron of the FXN gene, which encodes frataxin, an essential mitochondrial protein. To further characterise the molecular abnormalities associated with FRDA pathogenesis and to hasten drug screening, the development and use of animal and cellular models is considered essential. Studies of lower organisms have already contributed to understanding FRDA disease pathology, but mammalian cells are more related to FRDA patient cells in physiological terms. Methodology/Principal Findings: We have generated fibroblast cells and neural stem cells (NSCs) from control Y47R mice (9 GAA repeats) and GAA repeat expansion YG8R mice (190+120 GAA repeats). We then differentiated the NSCs in to neurons, oligodendrocytes and astrocytes as confirmed by immunocytochemical analysis of cell specific markers. The three YG8R mouse cell types (fibroblasts, NSCs and differentiated NSCs) exhibit GAA repeat stability, together with reduced expression of frataxin and reduced aconitase activity compared to control Y47R cells. Furthermore, YG8R cells also show increased sensitivity to oxidative stress and downregulation of Pgc-1α and antioxidant gene expression levels, especially Sod2. We also analysed various DNA mismatch repair (MMR) gene expression levels and found that YG8R cells displayed significant reduction in expression of several MMR genes, which may contribute to the GAA repeat stability. Conclusions/Significance: We describe the first fibroblast and NSC models from YG8R FRDA mice and we confirm that the NSCs can be differentiated into neurons and glia. These novel FRDA mouse cell models, which exhibit a FRDA-like cellular and molecular phenotype, will be valuable resources to further study FRDA molecular pathogenesis. They will also provide very useful tools for preclinical testing of frataxin-increasing compounds for FRDA drug therapy, for gene therapy, and as a source of cells for cell therapy testing in FRDA mice. © 2014 Sandi et al
Attracting and retaining health workers in rural areas: investigating nursesâ views on rural posts and policy interventions
<p>Abstract</p> <p>Background</p> <p>Kenya has bold plans for scaling up priority interventions nationwide, but faces major human resource challenges, with a lack of skilled workers especially in the most disadvantaged rural areas.</p> <p>Methods</p> <p>We investigated reasons for poor recruitment and retention in rural areas and potential policy interventions through quantitative and qualitative data collection with nursing trainees. We interviewed 345 trainees from four purposively selected Medical Training Colleges (MTCs) (166 pre-service and 179 upgrading trainees with prior work experience). Each interviewee completed a self-administered questionnaire including likert scale responses to statements about rural areas and interventions, and focus group discussions (FGDs) were conducted at each MTC.</p> <p>Results</p> <p>Likert scale responses indicated mixed perceptions of both living and working in rural areas, with a range of positive, negative and indifferent views expressed on average across different statements. The analysis showed that attitudes to working in rural areas were significantly positively affected by being older, but negatively affected by being an upgrading student. Attitudes to living in rural areas were significantly positively affected by being a student at the MTC furthest from Nairobi.</p> <p>During FGDs trainees raised both positive and negative aspects of rural life. Positive aspects included lower costs of living and more autonomy at work. Negative issues included poor infrastructure, inadequate education facilities and opportunities, higher workloads, and inadequate supplies and supervision. Particular concern was expressed about working in communities dominated by other tribes, reflecting Kenyaâs recent election-related violence.</p> <p>Quantitative and qualitative data indicated that students believed several strategies could improve rural recruitment and retention, with particular emphasis on substantial rural allowances and the ability to choose their rural location. Other interventions highlighted included provision of decent housing, and more rapid career advancement. However, recently introduced short term contracts in named locations were not favoured due to their lack of pension plans and job security.</p> <p>Conclusions</p> <p>This study identified a range of potential interventions to increase rural recruitment and retention, with those most favored by nursing students being additional rural allowances, and allowing choice of rural location. Greater investment is needed in information systems to evaluate the impact of such policies.</p
Cluster Lenses
Clusters of galaxies are the most recently assembled, massive, bound
structures in the Universe. As predicted by General Relativity, given their
masses, clusters strongly deform space-time in their vicinity. Clusters act as
some of the most powerful gravitational lenses in the Universe. Light rays
traversing through clusters from distant sources are hence deflected, and the
resulting images of these distant objects therefore appear distorted and
magnified. Lensing by clusters occurs in two regimes, each with unique
observational signatures. The strong lensing regime is characterized by effects
readily seen by eye, namely, the production of giant arcs, multiple-images, and
arclets. The weak lensing regime is characterized by small deformations in the
shapes of background galaxies only detectable statistically. Cluster lenses
have been exploited successfully to address several important current questions
in cosmology: (i) the study of the lens(es) - understanding cluster mass
distributions and issues pertaining to cluster formation and evolution, as well
as constraining the nature of dark matter; (ii) the study of the lensed objects
- probing the properties of the background lensed galaxy population - which is
statistically at higher redshifts and of lower intrinsic luminosity thus
enabling the probing of galaxy formation at the earliest times right up to the
Dark Ages; and (iii) the study of the geometry of the Universe - as the
strength of lensing depends on the ratios of angular diameter distances between
the lens, source and observer, lens deflections are sensitive to the value of
cosmological parameters and offer a powerful geometric tool to probe Dark
Energy. In this review, we present the basics of cluster lensing and provide a
current status report of the field.Comment: About 120 pages - Published in Open Access at:
http://www.springerlink.com/content/j183018170485723/ . arXiv admin note:
text overlap with arXiv:astro-ph/0504478 and arXiv:1003.3674 by other author
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Working relationships between obstetric care staff and their managers: a critical incident analysis
Background
Malawi continues to experience critical shortages of key health technical cadres that can adequately respond to Malawiâs disease burden. Difficult working conditions contribute to low morale and frustration among health care workers. We aimed to understand how obstetric care staff perceive their working relationships with managers.
Methods
A qualitative exploratory study was conducted in health facilities in Malawi between October and December 2008. Critical Incident Analysis interviews were done in government district hospitals, faith-based health facilities, and a sample of health centresâ providing emergency obstetric care. A total of 84 service providers were interviewed. Data were analyzed using NVivo 8 software.
Results
Poor leadership styles affected working relationships between obstetric care staff and their managers. Main concerns were managersâ lack of support for staff welfare and staff performance, lack of mentorship for new staff and junior colleagues, as well as inadequate supportive supervision. All this led to frustrations, diminished motivation, lack of interest in their job and withdrawal from work, including staff seriously considering leaving their post.
Conclusions
Positive working relationships between obstetric care staff and their managers are essential for promoting staff motivation and positive work performance. However, this study revealed that staff were demotivated and undermined by transactional leadership styles and behavior, evidenced by management by exception and lack of feedback or recognition. A shift to transformational leadership in nurse-manager relationships is essential to establish good working relationships with staff. Improved providersâ job satisfaction and staff retentionare crucial to the provision of high quality care and will also ensure efficiency in health care delivery in Malawi
Class in contemporary Britain: comparing the Cultural Capital and Social Exclusion (CCSE) project and the Great British Class Survey (GBCS)
The paper discusses the salience of class in Britain in relation to the experiment of the BBCâacademic partnership of the Great British Class Survey (GBCS). It addresses the claimed inauguration of a third phase in class analysis in the UK sparked by the experiment. This is done by considering three main issues. First, the GBCS experiment is situated in the context of various explorations of cultural class analyses, and chiefly in relation to the Cultural Capital and Social Exclusion (CCSE) project (ESRC funded 2003â6). Secondly, the focus is on the influence of the academic turn to big data for the procedures and claims of the project, and some implications of the methodological choices. Thirdly, attention is turned to the deleterious effects of commercial and institutional pressures on the current research culture in which the experiment exists
The FuturICT education accelerator
Education is a major force for economic and social wellbeing. Despite high aspirations, education at all levels can be expensive and ineffective. Three Grand Challenges are identified: (1) enable people to learn orders of magnitude more effectively, (2) enable people to learn at orders of magnitude less cost, and (3) demonstrate success by exemplary interdisciplinary education in complex systems science. A ten year âman-on-the-moonâ project is proposed in which FuturICTâs unique combination of Complexity, Social and Computing Sciences could provide an urgently needed transdisciplinary language for making sense of educational systems. In close dialogue with educational theory and practice, and grounded in the emerging data science and learning analytics paradigms, this will translate into practical tools (both analytical and computational) for researchers, practitioners and leaders; generative principles for resilient educational ecosystems; and innovation for radically scalable, yet personalised, learner engagement and assessment. The proposed Education Accelerator will serve as a âwind tunnelâ for testing these ideas in the context of real educational programmes, with an international virtual campus delivering complex systems education exploiting the new understanding of complex, social, computationally enhanced organisational structure developed within FuturICT
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