754 research outputs found
Light-Evoked Calcium Responses of Isolated Melanopsin- Expressing Retinal Ganglion Cells
A small number (\u3c2%) of mammalian retinal ganglion cells express the photopigment melanopsin and are intrinsically photosensitive (ipRGCs). Light depolarizes ipRGCs and increases intracellular calcium levels ( [Ca2+]i ) but the signaling cascades underlying these responses have yet to be elucidated. To facilitate physiological studies on these rare photoreceptors, highly enriched ipRGC cultures from neonatal rats were generated using anti-melanopsin-mediated plate adhesion (immunopanning). This novel approach enabled experiments on isolated ipRGCs, eliminating the potential confounding influence of rod/cone-driven input. Light induced a rise in [Ca2+]i (monitored using fura-2 imaging) in the immunopanned ipRGCs and the source of this Ca2+ signal was investigated. The Ca2+ responses were inhibited by 2-aminoethoxydiphenyl borate, SKF-96365 (1–2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl-1H-imidazole), flufenamic acid, lanthanum, and gadolinium, consistent with the involvement of canonical transient receptor potential (TRP) channels in ipRGC phototransduction. However, the contribution of direct Ca2+ flux through a putative TRP channel to ipRGC [Ca2+]i was relatively small, as most (~90%) of the light-induced Ca2+ responses could be blocked by preventing action potential firing with tetrodotoxin. The L-type voltage-gated Ca2+ channel (VGCC) blockers verapamil and (+)-cis-diltiazem significantly reduced the light-evoked Ca2+ responses, while the internal Ca2+ stores depleting agent thapsigargin had negligible effect. These results indicate that Ca2+ influx through VGCCs, activated after action potential firing, was the primary source for light-evoked elevations in ipRGC [Ca2+]i. Furthermore, concurrent Ca2+ imaging and cell-attached electrophysiological recordings demonstrated that the Ca2+ responses were highly correlated to spike frequency, thereby establishing a direct link between action potential firing and somatic [Ca2+]i in lightstimulated ipRGCs
A matched comparison study of hepatitis C treatment outcomes in the prison and community setting, and an analysis of the impact of prison release or transfer during therapy
Prisoners are a priority group for hepatitis C (HCV) treatment. Although treatment durations will become shorter using directly acting antivirals (DAAs), nearly half of prison sentences in Scotland are too short to allow completion of DAA therapy prior to release. The purpose of this study was to compare treatment outcomes between prison- and community-based patients and to examine the impact of prison release or transfer during therapy. A national database was used to compare treatment outcomes between prison treatment initiates and a matched community sample. Additional data were collected to investigate the impact of release or transfer on treatment outcomes. Treatment-naïve patients infected with genotype 1/2/3/4 and treated between 2009 and 2012 were eligible for inclusion. 291 prison initiates were matched with 1137 community initiates: SVRs were 61% (95% CI 55%-66%) and 63% (95% CI 60%-66%), respectively. Odds of achieving a SVR were not significantly associated with prisoner status (P=.33). SVRs were 74% (95% CI 65%-81%), 59% (95% CI 42%-75%) and 45% (95% CI 29%-62%) among those not released or transferred, transferred during treatment, or released during treatment, respectively. Odds of achieving a SVR were significantly associated with release (P<.01), but not transfer (P=.18). Prison-based HCV treatment achieves similar outcomes to community-based treatment, with those not released or transferred during treatment doing particularly well. Transfer or release during therapy should be avoided whenever possible, using anticipatory planning and medical holds where appropriate
Construct-level predictive validity of educational attainment and intellectual aptitude tests in medical student selection: meta-regression of six UK longitudinal studies
Background: Measures used for medical student selection should predict future performance during training. A problem for any selection study is that predictor-outcome correlations are known only in those who have been selected, whereas selectors need to know how measures would predict in the entire pool of applicants. That problem of interpretation can be solved by calculating construct-level predictive validity, an estimate of true predictor-outcome correlation across the range of applicant abilities.
Methods: Construct-level predictive validities were calculated in six cohort studies of medical student selection and training (student entry, 1972 to 2009) for a range of predictors, including A-levels, General Certificates of Secondary Education (GCSEs)/O-levels, and aptitude tests (AH5 and UK Clinical Aptitude Test (UKCAT)). Outcomes included undergraduate basic medical science and finals assessments, as well as postgraduate measures of Membership of the Royal Colleges of Physicians of the United Kingdom (MRCP(UK)) performance and entry in the Specialist Register. Construct-level predictive validity was calculated with the method of Hunter, Schmidt and Le (2006), adapted to correct for right-censorship of examination results due to grade inflation.
Results: Meta-regression analyzed 57 separate predictor-outcome correlations (POCs) and construct-level predictive validities (CLPVs). Mean CLPVs are substantially higher (.450) than mean POCs (.171). Mean CLPVs for first-year examinations, were high for A-levels (.809; CI: .501 to .935), and lower for GCSEs/O-levels (.332; CI: .024 to .583) and UKCAT (mean = .245; CI: .207 to .276). A-levels had higher CLPVs for all undergraduate and postgraduate assessments than did GCSEs/O-levels and intellectual aptitude tests. CLPVs of educational attainment measures decline somewhat during training, but continue to predict postgraduate performance. Intellectual aptitude tests have lower CLPVs than A-levels or GCSEs/O-levels.
Conclusions: Educational attainment has strong CLPVs for undergraduate and postgraduate performance, accounting for perhaps 65% of true variance in first year performance. Such CLPVs justify the use of educational attainment measure in selection, but also raise a key theoretical question concerning the remaining 35% of variance (and measurement error, range restriction and right-censorship have been taken into account). Just as in astrophysics, ‘dark matter’ and ‘dark energy’ are posited to balance various theoretical equations, so medical student selection must also have its ‘dark variance’, whose nature is not yet properly characterized, but explains a third of the variation in performance during training. Some variance probably relates to factors which are unpredictable at selection, such as illness or other life events, but some is probably also associated with factors such as personality, motivation or study skills
Potential of a multiparametric optical sensor for determining in situ the maturity components of red and white vitis vinifera wine grapes
A non-destructive fluorescence-based technique for evaluating Vitis vinifera L. grape maturity using a portable sensor (Multiplex ®) is presented. It provides indices of anthocyanins and chlorophyll in Cabernet Sauvignon, Merlot and Sangiovese red grapes and of flavonols and chlorophyll in Vermentino white grapes. The good exponential relationship between the anthocyanin index and the actual anthocyanin content determined by wet chemistry was used to estimate grape anthocyanins from in field sensor data during ripening. Marked differences were found in the kinetics and the amount of anthocyanins between cultivars and between seasons. A sensor-driven mapping of the anthocyanin content in the grapes, expressed as g/kg fresh weight, was performed on a 7-ha vineyard planted with Sangiovese. In the Vermentino, the flavonol index was favorably correlated to the actual content of berry skin flavonols determined by means of HPLC analysis of skin extracts. It was used to make a non-destructive estimate of the evolution in the flavonol concentration in grape berry samplings. The chlorophyll index was inversely correlated in linear manner to the total soluble solids (°Brix): it could, therefore, be used as a new index of technological maturity. The fluorescence sensor (Multiplex) possesses a high potential for representing an important innovative tool for controlling grape maturity in precision viticulture
Self-affirmation reduces the socioeconomic attainment gap in schools in England
Background. Studies in the USA show that school students from some ethnic backgrounds are susceptible to stereotype threat, that this undermines their academic performance, and that a series of virtually zero-cost self-affirmation writing exercises can reduce these adverse effects. In England, however, socioeconomic status (SES) is a much stronger predictor of academic success than is ethnic background.
Aims. This study investigates whether self-affirmation writing exercises can help close the SES attainment gap in England by increasing the academic performance of low-SES (but not higher-SES) school students.
Sample. Our sample consisted of students aged 11-14 in a secondary school in southern England (N = 562); of these, 128 were eligible for free school meals, a proxy
for low SES.
Methods. Students completed three short writing exercises throughout one academic year: those randomly assigned to an affirmed condition wrote about values that were important to them, and those assigned to a control condition wrote about a neutral topic.
Results. On average, the low-SES students had lower academic performance and reported experiencing more stereotype threat than their higher-SES peers. The selfaffirmation raised the academic performance of the low-SES students by 0.38 standard deviations but did not significantly affect the performance of the higher-SES students, thus reducing the SES performance gap by 62%. The self-affirmation also reduced the level of stress reported by the low-SES school students.
Conclusions. The benefits of this virtually zero-cost intervention compare favorably with those of other interventions targeting the SES academic attainment gap
Open letter from UK based academic scientists to the secretaries of state for digital, culture, media and sport and for health and social care regarding the need for independent funding for the prevention and treatment of gambling harms
First paragraph: Dear secretaries of state, As leading academic scientists studying gambling behaviours and its harms, we are writing to express our concern about the continuing support shown for the voluntary system of funding treatment, prevention and research in Great Britain. We feel compelled to write to you following the Betting and Gaming Council’s (BGC) recent announcement (17 June 2020) that five of its operators will now allocate the long awaited increase in funding for prevention and treatment, first promised on 2 August 2019, to GambleAware rather than the charity Action Against Gambling Harms. Irrespective of which organisation funds are given to, the BGC’s announcement exemplifies the longstanding weakness of a funding system that allows the gambling industry to regulate the availability and distribution of vital funds to address gambling harms across our communities. As we outline below, the continuance of this arrangement produces several negative effects that undermine the collective effort to reduce harms from gambling. It is also our belief that funds for research into gambling harms and their reduction should primarily be distributed through recognised independent organisations, such as UK Research and Innovation. We hereby urge you, as the secretaries of state with responsibilities for addressing gambling harms, to implement a statutory levy to fund effective prevention and treatment of gambling harms that is free both from industry influence and the perception of industry influence...... [Read more in the article]Additional co-authors: Carolyn Downs, Simon Dymond, Emanuele Fino, Elizabeth Goyder, Cindy Gray, Mark Griffiths, Peter Grindrod, Lee Hogan, Alice Hoon, Richard James, Bev John, Jill Manthorpe, Jim McCambridge, David McDaid, Martin McKee, Sally McManus, Antony Moss, Caroline Norrie, David J Nutt, Jim Orford, Rob Pryce, Gerda Reith, Amanda Roberts, Emmett Roberts, Gareth Roderique-Davies, Jim Rogers, Robert D Rogers, Stephen Sharman, John Strang, Richard Tunney, John Turner, Robert West, David Zendl
‘It's the relationship you develop with them’: emotional intelligence in nurse leadership. A qualitative study
Learning to live with Parkinson’s disease in the family unit:an interpretative phenomenological analysis of well-being
We investigated family members’ lived experience of Parkinson’s disease (PD) aiming to investigate opportunities for well-being. A lifeworld-led approach to healthcare was adopted. Interpretative phenomenological analysis was used to explore in-depth interviews with people living with PD and their partners. The analysis generated four themes: It’s more than just an illness revealed the existential challenge of diagnosis; Like a bird with a broken wing emphasizing the need to adapt to increasing immobility through embodied agency; Being together with PD exploring the kinship within couples and belonging experienced through support groups; and Carpe diem! illuminated the significance of time and fractured future orientation created by diagnosis. Findings were interpreted using an existential-phenomenological theory of well-being. We highlighted how partners shared the impact of PD in their own ontological challenges. Further research with different types of families and in different situations is required to identify services required to facilitate the process of learning to live with PD. Care and support for the family unit needs to provide emotional support to manage threats to identity and agency alongside problem-solving for bodily changes. Adopting a lifeworld-led healthcare approach would increase opportunities for well-being within the PD illness journey
Open letter from UK based academic scientists to the secretaries of state for digital, culture, media and sport and for health and social care regarding the need for independent funding for the prevention and treatment of gambling harms
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