605 research outputs found
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Oceanographic observations at the Amundsen sea shelf break
Introduction:
The continental shelf environment of the Amundsen and Bellingshausen seas differs markedly from that of the other circumpolar seas, where water temperatures are close to the surface freezing point throughout. In the Amundsen/Bellingshausen sector near-freezing temperatures are encountered only in the upper few hundred metres of the water column. Below this surface layer a broad thermocline trends towards upper Circumpolar Deep Water (uCDW), which is found in a form that is almost unmodified from its off-shelf manifestation (Giulivi and Jacobs, 1996). This means that the ice shelves of the Amundsen and Bellingshausen seas experience ocean temperatures some three degrees warmer than those experienced by the other Antarctic ice shelves, and the rates of basal melting are correspondingly high (Jacobs et al., 1996)
Multi-time delay, multi-point Linear Stochastic Estimation of a cavity shear layer velocity from wall-pressure measurements
Multi-time-delay Linear Stochastic Estimation (MTD-LSE) technique is thoroughly described, focusing on its fundamental properties and potentialities. In the multi-time-delay ap- proach, the estimate of the temporal evolution of the velocity at a given location in the flow field is obtained from multiple past samples of the unconditional sources. The technique is applied to estimate the velocity in a cavity shear layer flow, based on wall-pressure measurements from multiple sensor
Social Services Will Not Touch us with a Barge Pole’: Social Care Provision for Older Prisoners
Older prisoners are the fastest growing subgroup in the English and Welsh prison estate. Older prisoners have high levels of health and social care needs. This mixed method study involved the distribution of a questionnaire examining the availability of health and social care services for older prisoners to all prisons housing adult males in England and Wales, followed by qualitative telephone interviews with representatives from eight prisons. Over half of establishments had some contact with external social care services but reported significant difficulties in arranging care for individuals. A professional lead for older prisoners had been identified in 81% of establishments; however the value of this role to positively affect practice appeared questionable. Statutory social care was often non-existent in prison due to the lack of understanding of what it constituted and who was responsible for its provision
Recruitment and retention strategies and the examination of attrition bias in a randomised controlled trial in children’s centres serving families in disadvantaged areas of England
Background
Failure to retain participants in randomised controlled trials and longitudinal studies can cause significant methodological problems. We report the recruitment and retention strategies of a randomised controlled trial to promote fire-related injury prevention in families with pre-school children attending children’s centres in disadvantaged areas in England.
Methods
Thirty-six children’s centres were cluster randomised into one of three arms of a 12-month fire-related injury prevention trial. Two arms delivered safety interventions and there was one control arm. Retention rates compared the numbers of participants responding to the 12-month questionnaire to the number recruited to the trial. Multivariable random effects logistic regression was used to explore factors independently associated with participant retention.
Results
The trial exceeded its required sample size through the use of multiple recruitment strategies. All children’s centres remained in the study, despite increased reorganisation. Parent retention was 68% at 12 months, ranging from 65% to 70% across trial arms and from 62% to 74% across trial sites. There was no significant difference in the rates of retention between trial arms (p = 0.58) or between trial sites (p = 0.16). Retention was significantly lower amongst mothers aged 16–25 years than older mothers [adjusted odds ratio (AOR) 0.57, 95% CI 0.41, 0.78], those living in non-owner occupied accommodation than in owner occupied accommodation (AOR 0.53, 95% CI 0.38, 0.73) and those living in more disadvantaged areas (most versus least disadvantaged quintiles AOR 0.50, 95% CI 0.30, 0.82).
Conclusions
Studies recruiting disadvantaged populations should measure and report attrition by socioeconomic factors to enable determination of the extent of attrition bias and estimation of its potential impact on findings. Where differential attrition is anticipated, consideration should be given to over-sampling during recruitment and targeted and more intensive strategies of participant retention in these sub-groups. In transient populations collection of multiple sources of contact information at recruitment and throughout the study may aid retention
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Novel polyvinylpyrrolidones to improve delivery of poorly-water soluble drugs; from design to synthesis and evaluation
Polyvinylpyrrolidone is a widely used in tablet formulations with the linear form acting as a wetting agent and disintegrant whereas the cross-linked form is a super-disintegrant. We have previously reported that simply mixing the commercial cross-linked polymer with ibuprofen disrupted drug crystallinity with consequent improvements in drug dissolution behavior. In this study, we have designed and synthesized novel cross-linking agents containing a range of oligoether moieties which have then be polymerized with vinylpyrrolidone to generate a suite of novel excipients with enhanced hydrogen-bonding capabilities. The polymers have a porous surface and swell in most common solvents and in water; properties which suggest their value as disintegrants. The polymers were evaluated in simple physical mixtures with ibuprofen as a model poorly-water soluble drug. The results show that the novel PVPs induce the drug to become “X-ray amorphous”, which increased dissolution to a greater extent than that seen with commercial cross-linked PVP. The polymers stabilize the amorphous drug with no evidence for recrystallization seen after 20 weeks storage
HNF1B mutations are associated with a Gitelman-like tubulopathy that develops during childhood
Mutations in the transcription factor hepatocyte nuclear factor 1B (HNF1B) are the most common inherited cause of renal malformations, yet also associated with renal tubular dysfunction, most prominently magnesium wasting with hypomagnesemia. The presence of hypomagnesemia has been proposed to help select appropriate patients for genetic testing. Yet, in a large cohort, hypomagnesemia was discriminatory only in adult, but not in pediatric patients. We therefore investigated whether hypomagnesemia and other biochemical changes develop with age.This article is freely available via Open Access. Click on the Additional Link to access full-text
A 3D scanning system for biomedical purposes
The use of three-dimensional (3D) scanning systems for acquiring the external shape features of biological objects has recently been gaining popularity in the biomedical field. A simple, low cost, 3D scanning syste
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