811 research outputs found
Living in a risky world: the onset and ontogeny of an integrated antipredator phenotype in a coral reef fish
Prey individuals with complex life-histories often cannot predict the type of risk environment to which they will be exposed at each of their life stages. Because the level of investment in defences should match local risk conditions, we predict that these individuals should have the ability to modulate the expression of an integrated defensive phenotype, but this switch in expression should occur at key life-history transitions. We manipulated background level of risk in juvenile damselfish for four days following settlement (a key life-history transition) or 10 days post-settlement, and measured a suite of physiological and behavioural variables over 2 weeks. We found that settlement-stage fish exposed to high-risk conditions displayed behavioural and physiological alterations consistent with high-risk phenotypes, which gave them a survival advantage when exposed to predators. These changes were maintained for at least 2 weeks. The same exposure in post-settlement fish failed to elicit a change in some traits, while the expression of other traits disappeared within a week. Our results are consistent with those expected from phenotypic resonance. Expression of antipredator traits may be masked if individuals are not exposed to certain conditions at key ontogenetic stages
Questioning policy, youth participation and lifestyle sports
Young people have been identified as a key target group for whom participation in sport and physical activity could have important benefits to health and wellbeing and consequently have been the focus of several government policies to increase participation in the UK. Lifestyle sports represent one such strategy for encouraging and sustaining new engagements in sport and physical activity in youth groups, however, there is at present a lack of understanding of the use of these activities within policy contexts. This paper presents findings from a government initiative which sought to increase participation in sport for young people through provision of facilities for mountain biking in a forest in south-east England. Findings from qualitative research with 40 young people who participated in mountain biking at the case study location highlight the importance of non-traditional sports as a means to experience the natural environments through forms of consumption which are healthy, active and appeal to their identities. In addition, however, the paper raises questions over the accessibility of schemes for some individuals and social groups, and the ability to incorporate sports which are inherently participant-led into state-managed schemes. Lifestyle sports such as mountain biking involve distinct forms of participation which present a challenge for policy-makers who seek to create and maintain sustainable communities of youth participants
Improving quality of care and outcome at very preterm birth: the Preterm Birth research programme, including the Cord pilot RCT
BACKGROUND: Being born very premature (i.e. before 32 weeks’ gestation) has an impact on survival and quality of life. Improving care at birth may improve outcomes and parents’ experiences. OBJECTIVES: To improve the quality of care and outcomes following very preterm birth. DESIGN: We used mixed methods, including a James Lind Alliance prioritisation, a systematic review, a framework synthesis, a comparative review, qualitative studies, development of a questionnaire tool and a medical device (a neonatal resuscitation trolley), a survey of practice, a randomised trial and a protocol for a prospective meta-analysis using individual participant data. SETTING: For the prioritisation, this included people affected by preterm birth and health-care practitioners in the UK relevant to preterm birth. The qualitative work on preterm birth and the development of the questionnaire involved parents of infants born at three maternity hospitals in southern England. The medical device was developed at Liverpool Women’s Hospital. The survey of practice involved UK neonatal units. The randomised trial was conducted at eight UK tertiary maternity hospitals. PARTICIPANTS: For prioritisation, 26 organisations and 386 individuals; for the interviews and questionnaire tool, 32 mothers and seven fathers who had a baby born before 32 weeks’ gestation for interviews evaluating the trolley, 30 people who had experienced it being used at the birth of their baby (19 mothers, 10 partners and 1 grandmother) and 20 clinicians who were present when it was being used; for the trial, 261 women expected to have a live birth before 32 weeks’ gestation, and their 276 babies. INTERVENTIONS: Providing neonatal care at very preterm birth beside the mother, and with the umbilical cord intact; timing of cord clamping at very preterm birth. MAIN OUTCOMES MEASURES: Research priorities for preterm birth; feasibility and acceptability of the trolley; feasibility of a randomised trial, death and intraventricular haemorrhage. REVIEW METHODS: Systematic review of Cochrane reviews (umbrella review); framework synthesis of ethics aspects of consent, with conceptual framework to inform selection criteria for empirical and analytical studies. The comparative review included studies using a questionnaire to assess satisfaction with care during childbirth, and provided psychometric information. RESULTS: Our prioritisation identified 104 research topics for preterm birth, with the top 30 ranked. An ethnographic analysis of decision-making during this process suggested ways that it might be improved. Qualitative interviews with parents about their experiences of very preterm birth identified two differences with term births: the importance of the staff appearing calm and of staff taking control. Following a comparative review, this led to the development of a questionnaire to assess parents’ views of care during very preterm birth. A systematic overview summarised evidence for delivery room neonatal care and revealed significant evidence gaps. The framework synthesis explored ethics issues in consent for trials involving sick or preterm infants, concluding that no existing process is ideal and identifying three important gaps. This led to the development of a two-stage consent pathway (oral assent followed by written consent), subsequently evaluated in our randomised trial. Our survey of practice for care at the time of birth showed variation in approaches to cord clamping, and that no hospitals were providing neonatal care with the cord intact. We showed that neonatal care could be provided beside the mother using either the mobile neonatal resuscitation trolley we developed or existing equipment. Qualitative interviews suggested that neonatal care beside the mother is valued by parents and acceptable to clinicians. Our pilot randomised trial compared cord clamping after 2 minutes and initial neonatal care, if needed, with the cord intact, with clamping within 20 seconds and initial neonatal care after clamping. This study demonstrated feasibility of a large UK randomised trial. Of 135 infants allocated to cord clamping ≥ 2 minutes, 7 (5.2%) died and, of 135 allocated to cord clamping ≤ 20 seconds, 15 (11.1%) died (risk difference –5.9%, 95% confidence interval –12.4% to 0.6%). Of live births, 43 out of 134 (32%) allocated to cord clamping ≥ 2 minutes had intraventricular haemorrhage compared with 47 out of 132 (36%) allocated to cord clamping ≤ 20 seconds (risk difference –3.5%, 95% CI –14.9% to 7.8%). LIMITATIONS: Small sample for the qualitative interviews about preterm birth, single-centre evaluation of neonatal care beside the mother, and a pilot trial. CONCLUSIONS: Our programme of research has improved understanding of parent experiences of very preterm birth, and informed clinical guidelines and the research agenda. Our two-stage consent pathway is recommended for intrapartum clinical research trials. Our pilot trial will contribute to the individual participant data meta-analysis, results of which will guide design of future trials. FUTURE WORK: Research in preterm birth should take account of the top priorities. Further evaluation of neonatal care beside the mother is merited, and future trial of alternative policies for management of cord clamping should take account of the meta-analysis. STUDY REGISTRATION: This study is registered as PROSPERO CRD42012003038 and CRD42013004405. In addition, Current Controlled Trials ISRCTN21456601. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 7, No. 8. See the NIHR Journals Library website for further project information
A multicentre, randomised controlled trial of PDSAFE, a physiotherapist-delivered fall prevention programme for people with Parkinson’s
This is the author accepted manuscript. The final version is available from BMJ Publishing Group via the DOI in this record.Objective: To estimate the effect of a physiotherapist-delivered fall-prevention programme for people with
Parkinson’s (PwP).
Methods: People at risk of falls with confirmed Parkinson’s were recruited to this multi-centre, pragmatic,
investigator blind, individually randomised controlled trial with pre-specified sub-group analyses. 474 PwP
(Hoehn and Yahr 1-4) were randomised: 238 allocated to a physiotherapy programme and 236 to control.
All participants had routine care; the control group received a DVD about Parkinson’s and single advice
session at trial completion. The intervention group (PDSAFE) had an individually tailored, progressive
home-based fall-avoidance strategy training programme with balance and strengthening exercises.
The primary outcome was risk of repeat-falling, collected by self-report monthly diaries, 0 to 6 months
post-randomisation. Secondary outcomes included, Mini-BESTest for balance, chair stand test, Falls
Efficacy, freezing of gait, health related quality of life (Euroqol EQ-5D), Geriatric Depression Scale, Physical
Activity Scale for the Elderly and Parkinson’s disease Questionnaire, fractures and rate of near-falling.
Results: Average age, 72 years and 266 (56%) were men. By 6 months 116 (55%) of the control group, and
125 (61.5%) of the intervention group reported repeat falls (controlled odds ratio 1.21, 95% confidence
interval 0.74 to 1.98, P=0.447). Secondary sub-group analyses suggested a different response to the
intervention between moderate and severe disease severity groups. Balance, falls efficacy and chair stand
time improved with near-falls reduced in the intervention arm.
Conclusion: PDSAFE did not reduce falling in this pragmatic trial of PwP. Other functional tasks improved
and reduced fall rates were apparent among those with moderate disease.Department of HealthNational Institute for Health Research (NIHR
The cyclin-dependent kinase inhibitor p57(Kip2) is epigenetically regulated in carboplatin resistance and results in collateral sensitivity to the CDK inhibitor seliciclib in ovarian cancer
Carboplatin remains a first-line agent in the management of epithelial ovarian cancer (EOC). Unfortunately, platinum-resistant disease ultimately occurs in most patients. Using a novel EOC cell line with acquired resistance to carboplatin: PEO1CarbR, genome-wide micro-array profiling identified the cyclin-dependent kinase inhibitor p57(Kip2) as specifically downregulated in carboplatin resistance. Presently, we describe confirmation of these preliminary data with a variety of approaches
Biomechanical analysis of the penalty-corner drag-flick of elite male and female hockey players
The aim of this study was to analyse the kinematic sequencing in the penalty-corner drag-flicks of elite male and female field hockey players of international calibre. Thirteen participants (one skilled male drag-flicker and six male and six female elite players) participated in the study. An optoelectronic motion analysis system was used to capture the drag-flicks with six cameras, sampling at 250 Hz. Select ground reaction force parameters were obtained from a force platform which registered the last support of the front foot. Twenty trials were captured from each subject. Both player groups showed significantly (p < 0.05) smaller ball velocity at release, peak angular velocity of the pelvis, and negative and positive peak angular velocities of the stick than the skilled subject. Normalised ground reaction forces of the gender groups were also smaller than that of the skilled drag-flicker. By comparing these players we established that the cues of the skill level are a wide stance, a whipping action (rapid back lift) of the stick followed by an explosive sequential movement of the pelvis, upper trunk and stick
Strong negative self regulation of Prokaryotic transcription factors increases the intrinsic noise of protein expression
Background
Many prokaryotic transcription factors repress their own transcription. It is often asserted that such regulation enables a cell to homeostatically maintain protein abundance. We explore the role of negative self regulation of transcription in regulating the variability of protein abundance using a variety of stochastic modeling techniques.
Results
We undertake a novel analysis of a classic model for negative self regulation. We demonstrate that, with standard approximations, protein variance relative to its mean should be independent of repressor strength in a physiological range. Consequently, in that range, the coefficient of variation would increase with repressor strength. However, stochastic computer simulations demonstrate that there is a greater increase in noise associated with strong repressors than predicted by theory. The discrepancies between the mathematical analysis and computer simulations arise because with strong repressors the approximation that leads to Michaelis-Menten-like hyperbolic repression terms ceases to be valid. Because we observe that strong negative feedback increases variability and so is unlikely to be a mechanism for noise control, we suggest instead that negative feedback is evolutionarily favoured because it allows the cell to minimize mRNA usage. To test this, we used in silico evolution to demonstrate that while negative feedback can achieve only a modest improvement in protein noise reduction compared with the unregulated system, it can achieve good improvement in protein response times and very substantial improvement in reducing mRNA levels.
Conclusions
Strong negative self regulation of transcription may not always be a mechanism for homeostatic control of protein abundance, but instead might be evolutionarily favoured as a mechanism to limit the use of mRNA. The use of hyperbolic terms derived from quasi-steady-state approximation should also be avoided in the analysis of stochastic models with strong repressors
Coral Reef Fish Rapidly Learn to Identify Multiple Unknown Predators upon Recruitment to the Reef
Organisms often undergo shifts in habitats as their requirements change with ontogeny
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