104 research outputs found
Experimental verification of an Oseen flow slender body theory
Consider uniform flow past four slender bodies with elliptical cross-section of
constant ellipticity along the length of 0, 0.125, 0.25 and 0.375, respectively, for each
body. Here, ellipticity is defined as the ratio of the semiminor axis of the ellipse to
the semimajor axis. The bodies have a pointed nose which gradually increases in
cross-section with a radius of curvature 419mm to a mid-section which then remains
constant up to a blunt end section with semimajor axis diameter 160 mm, the total
length of all bodies being 800 mm. The bodies are side-mounted within a low-speed
wind tunnel with an operational wind speed of the order 30ms−1. The side force (or
lift) is measured within an angle of attack range of −3◦ to 3◦ such that the body is
rotated about the major axis of the ellipse cross-section. The lift slope is determined
for each body, and how it varies with ellipticity. It is found that this variance follows
a straight line which steadily increases with increasing ellipticity. It is shown that
this result is predicted by a recently developed Oseen flow slender body theory, and
cannot be predicted by either inviscid flow slender body theory or viscous crossflow
theories based upon the Allen and Perkins method
The Effect of Causal Attributions and Beliefs on the Acceptability of Interventions for Self-Injurous Behaviour and Research Portfolio
Carers' beliefs and attributions about the causes of challenging behaviour in people with learning disabilities may influence their perceived acceptability of treatment interventions for such behaviours, and therefore potentially affect intervention implementation. The current study, using a questionnaire measure with 154 institutional nursing staff examined; (i) their ratings of the acceptability of a number of interventions, including more recently developed non-aversive procedures, for self-injurious behaviour, (ii) the nature of staff beliefs and attributions about the causes of self-injury and (iii) whether such beliefs and attributions predicted ratings of treatment acceptability. Results suggested that nursing staff rated the acceptability of interventions according to the level of aversiveness, with less aversive interventions rated as more acceptable. Subjects held wide-ranging attributions and beliefs about the causes of Sffi. However, causal attributions and beliefs had little predictive value for the acceptability of treatment procedures. Methodological shortcomings of the present study, and suggestions for future research are discussed
The function of intimate partner violence for female perpetrators: an examination using multiple sequential functional analysis
Background. Studies which have found high rates of intimate partner violence have identified that women use as much, if not more, partner violence than men. Research studies into the aetiology of female partner violence have identified a number of related risk factors but there is no single theory which adequately explains the processes by which partner violence develops and is maintained in the learning histories of females. Treatment and risk
assessment options for this group are under developed and it is critical that research is undertaken to understand this phenomenon in order to provide effective interventions in the future.
Study aim. This study aims to use a multiple sequential functional analysis to explore whether behavioural principles, when applied to the developmental histories of females, can be used to understand the trajectory of partner violence across the lifespan.
Method. Three female participants were recruited from Probation and Forensic Psychology services in the East Midlands, UK. Clinical interviews were conducted with participants using a biographical format to collate detailed information around all aspects of female’s histories, current functioning and index offending. For accuracy, interview data was triangulated with data from professional interviews and file review. The multiple sequential functional analysis
was conducted according to the principles of radical behaviourism and applied functional analysis. Data was utilised in the analysis based on the pragmatic truth criterion of functional contextualism.
Results. The results are three detailed functional analytic case studies that show the development of partner violence for each participant from formative experiences to the current index offence. The results demonstrate that functional analytic principles can be used to understand the developmental pathway of partner violence in a small group of females. Synthesis of the three case studies identifies that violence and inciting violence in a male partner has functional value for these women and that issues such as power and control are important factors in female use of partner violence. Other factors of commonality are history of childhood and adulthood abuse, gendered belief systems, inferred insecure attachment style and borderline personality traits.
Discussion. Power and control were significant factors in these women’s learning histories, both in terms of the victimisation and abuse they had suffered but also in their own use of violence and coercive behaviours. The findings that partner violence and inciting partner violence holds functional value for this group of women is controversial and directly contrasts with the feminist literature. This has important implications for future research and clinical
implications. A strength of the current methodology is that it identifies subtle differences amongst learning histories, which has implications for development of individualised treatment planning and risk assessment for this under represented group
Treatment-seeking rates in malaria endemic countries
BACKGROUND: The proportion of individuals who seek treatment for fever is an important quantity in understanding access to and use of health systems, as well as for interpreting data on disease incidence from routine surveillance systems. For many malaria endemic countries (MECs), treatment-seeking information is available from national household surveys. The aim of this paper was to assemble sub-national estimates of treatment-seeking behaviours and to predict national treatment-seeking measures for all MECs lacking household survey data. METHODS: Data on treatment seeking for fever were obtained from Demographic and Health Surveys, Malaria Indicator Surveys and Multiple Cluster Indicator Surveys for every MEC and year that data were available. National-level social, economic and health-related variables were gathered from the World Bank as putative covariates of treatment-seeking rates. A generalized additive mixed model (GAMM) was used to estimate treatment-seeking behaviours for countries where survey data were unavailable. Two separate models were developed to predict the proportion of fever cases that would seek treatment at (1) a public health facility or (2) from any kind of treatment provider. RESULTS: Treatment-seeking data were available for 74 MECs and modelled for the remaining 24. GAMMs found that the percentage of pregnant women receiving prenatal care, vaccination rates, education level, government health expenditure, and GDP growth were important predictors for both categories of treatment-seeking outcomes. Treatment-seeking rates, which varied both within and among regions, revealed that public facilities were not always the primary facility type used. CONCLUSIONS: Estimates of treatment-seeking rates show how health services are utilized and help correct reported malaria case numbers to obtain more accurate measures of disease burden. The assembled and modelled data demonstrated that while treatment-seeking rates have overall increased over time, access remains low in some malaria endemic regions and utilization of government services is in some areas limited
To Achieve Big Wins for Terrestrial Conservation, Prioritize Protection of Ecoregions Closest to Meeting Targets
Most of the terrestrial world is experiencing high rates of land conversion despite growth of the global protected area (PA) network. There is a need to assess whether the current global protection targets are achievable across all major ecosystem types and to identify those that need urgent protection. Using recent rates of habitat conversion and protection and the latest terrestrial ecoregion map, we show that if the same approach to PA establishment that has been undertaken over the past three decades continues, 558 of 748 ecoregions (ca. 75%) will not meet an aspirational 30% area protection target by 2030. A simple yet strategic acquisition plan that considers realistic futures around habitat loss and PA expansion could more than double the number of ecoregions adequately protected by 2030 given current funding constraints. These results highlight the importance of including explicit ecoregional representation targets within any new post-2020 global PA target
Population coverage of artemisinin-based combination treatment in children younger than 5 years with fever and Plasmodium falciparum infection in Africa, 2003–2015: a modelling study using data from national surveys
Background Artemisinin-based combination therapies (ACTs) are the most effective treatment for uncomplicated
Plasmodium falciparum malaria infection. A commonly used indicator for monitoring and assessing progress in
coverage of malaria treatment is the proportion of children younger than 5 years with reported fever in the previous
14 days who have received an ACT. We propose an improved indicator that incorporates parasite infection status (as
assessed by a rapid diagnostic test [RDT]), which is available in recent household surveys. In this study we estimated
the annual proportion of children younger than 5 years with fever and a positive RDT in Africa who received an ACT
in 2003–15.
Methods Our modelling study used cross-sectional data on treatment for fever and RDT status for children younger
than 5 years compiled from all nationally available representative household surveys (the Malaria Indicator Surveys,
Demographic and Health Surveys, and Multiple Indicator Cluster Surveys) across sub-Saharan Africa between 2003
and 2015. Estimates for the proportion of children younger than 5 years with a fever within the previous 14 days and
P falciparum infection assessed by RDT who received an ACT were incorporated in a generalised additive mixed
model, including data on ACT distributions, to estimate coverage across all countries and time periods. We did
random effects meta-analyses to examine individual, household, and community effects associated with ACT coverage.
Findings We obtained data on 201 704 children younger than 5 years from 103 surveys (22 MIS, 61 DHS, and 20 MICS)
across 33 countries. RDT results were available for 40 of these surveys including 40 261 (20%) children, and we
predicted RDT status for the remaining 161 443 (80%) children. Our results showed that ACT coverage in children
younger than 5 years with a fever and P falciparum infection increased across sub-Saharan Africa in 2003–15, but even
in 2015, only 19·7% (95% CI 15·6–24·8) of children younger than 5 years with a fever and P falciparum infection
received an ACT. In meta-analyses, children younger than 5 years were more likely to receive an ACT for fever and
P falciparum infection if they lived in an urban area (vs rural area; odds ratio [OR] 1·18, 95% CI 1·06–1·31), had
household wealth above the national median (vs wealth below the median; OR 1·26, 1·16–1·39), had a caregiver with
any education (vs no education; OR 1·31, 1·22–1·41), had a household insecticide-treated net (ITN; vs no ITN; OR 1·21,
1·13–1·29), were older than 2 years (vs ≤2 years; OR 1·09, 1·01–1·17), or lived in an area with a higher mean
P falciparum prevalence in children aged 2–10 years (OR 1·12, 1·02–1·23). In the subgroup of children for whom
treatment was sought, those who sought treatment in the public sector were more likely to receive an ACT (vs the
private sector; OR 3·18, 2·67–3·78).
Interpretation Despite progress during the 2003–15 malaria programme, ACT treatment for children with malaria
remains unacceptably low. More work is needed at the country level to understand how health-care access, service
delivery, and ACT supply might be improved to ensure appropriate treatment for all children with malaria
Plasmodium vivax transmission in Africa
Malaria in sub-Saharan Africa has historically been almost exclusively attributed to Plasmodium falciparum (Pf). Current diagnostic and surveillance systems in much of sub-Saharan Africa are not designed to identify or report non-Pf human malaria infections accurately, resulting in a dearth of routine epidemiological data about their significance. The high prevalence of Duffy negativity provided a rationale for excluding the possibility of Plasmodium vivax (Pv) transmission. However, review of varied evidence sources including traveller infections, community prevalence surveys, local clinical case reports, entomological and serological studies contradicts this viewpoint. Here, these data reports are weighted in a unified framework to reflect the strength of evidence of indigenous Pv transmission in terms of diagnostic specificity, size of individual reports and corroboration between evidence sources. Direct evidence was reported from 21 of the 47 malaria-endemic countries studied, while 42 countries were attributed with infections of visiting travellers. Overall, moderate to conclusive evidence of transmission was available from 18 countries, distributed across all parts of the continent. Approximately 86.6 million Duffy positive hosts were at risk of infection in Africa in 2015. Analysis of the mechanisms sustaining Pv transmission across this continent of low frequency of susceptible hosts found that reports of Pv prevalence were consistent with transmission being potentially limited to Duffy positive populations. Finally, reports of apparent Duffy-independent transmission are discussed. While Pv is evidently not a major malaria parasite across most of sub-Saharan Africa, the evidence presented here highlights its widespread low-level endemicity. An increased awareness of Pv as a potential malaria parasite, coupled with policy shifts towards species-specific diagnostics and reporting, will allow a robust assessment of the public health significance of Pv, as well as the other neglected non-Pf parasites, which are currently invisible to most public health authorities in Africa, but which can cause severe clinical illness and require specific control intervention
Standardized reporting of the costs of management interventions for biodiversity conservation
Effective conservation management interventions must combat threats and deliver conservation benefits at costs that can be achieved within limited budgets. Considerable effort has focused on measuring the potential benefits of conservation interventions but explicit quantification of implementation costs has been rare. Even when costs have been quantified, haphazard and inconsistent reporting means that published values are difficult to interpret. This reporting deficiency hinders progress towards building a collective understanding of the costs of management interventions across projects, and thus limits our ability to identify efficient solutions to conservation problems or attract adequate funding. We address this challenge by proposing a standardized approach to describing costs reported for conservation interventions. These standards call for researchers and practitioners to ensure the cost data they collect and report on provide enough contextual information that readers and future users can interpret the data appropriately. We suggest these standards be adopted by major conservation organizations, conservation science institutions, and journals, so that cost reporting is comparable between studies. This would support shared learning and enhance our ability to identify and perform cost-effective conservation.Funding was provided by CEED (GDI and workshop), an ARC Laureate Fellowship (HPP, BM, VA and JM), Arcadia (WJS), the Natural Environment Research Council (LVD, NE/K015419/1; NE/N014472/1) and the Wildlife Conservation Society (AJP)
Transcutaneous Auricular Vagus Nerve Stimulation-Paired Rehabilitation for Oromotor Feeding Problems in Newborns: An Open-Label Pilot Study
Neonates born premature or who suffer brain injury at birth often have oral feeding dysfunction and do not meet oral intake requirements needed for discharge. Low oral intake volumes result in extended stays in the hospital (\u3e2 months) and can lead to surgical implant and explant of a gastrostomy tube (G-tube). Prior work suggests pairing vagus nerve stimulation (VNS) with motor activity accelerates functional improvements after stroke, and transcutaneous auricular VNS (taVNS) has emerged as promising noninvasive form of VNS. Pairing taVNS with bottle-feeding rehabilitation may improve oromotor coordination and lead to improved oral intake volumes, ultimately avoiding the need for G-tube placement. We investigated whether taVNS paired with oromotor rehabilitation is tolerable and safe and facilitates motor learning in infants who have failed oral feeding. We enrolled 14 infants [11 premature and 3 hypoxic–ischemic encephalopathy (HIE)] who were slated for G-tube placement in a prospective, open-label study of taVNS-paired rehabilitation to increase feeding volumes. Once-daily taVNS was delivered to the left tragus during bottle feeding for 2 weeks, with optional extension. The primary outcome was attainment of oral feeding volumes and weight gain adequate for discharge without G-tube while also monitoring discomfort and heart rate (HR) as safety outcomes. We observed no adverse events related to stimulation, and stimulation-induced HR reductions were transient and safe and likely confirmed vagal engagement. Eight of 14 participants (57%) achieved adequate feeding volumes for discharge without G-tube (mean treatment length: 16 ± 6 days). We observed significant increases in feeding volume trajectories in responders compared with pre-stimulation (p \u3c 0.05). taVNS-paired feeding rehabilitation appears safe and may improve oral feeding in infants with oromotor dyscoordination, increasing the rate of discharge without G-tube, warranting larger controlled trials
The impact of digital health technologies on tuberculosis treatment: a systematic review
Digital technologies are increasingly harnessed to support treatment of persons with
tuberculosis (TB). Since in-person directly observed treatment (DOT) can be resource intensive and
challenging to implement, these technologies may have the potential to improve adherence and clinical
outcomes. We reviewed the effect of these technologies on TB treatment adherence and patient outcomes.
We searched several bibliographical databases for studies reporting the effect of digital interventions,
including short message service (SMS), video-observed therapy (VOT) and medication monitors (MMs),
to support treatment for active TB. Only studies with a control group and which reported effect estimates
were included.
Four trials showed no statistically significant effect on treatment completion when SMS was added to
standard care. Two observational studies of VOT reported comparable treatment completion rates when
compared with in-person DOT. MMs increased the probability of cure (RR 2.3, 95% CI 1.6–3.4) in one
observational study, and one trial reported a statistically significant reduction in missed treatment doses
relative to standard care (adjusted means ratio 0.58, 95% CI 0.42–0.79).
Evidence of the effect of digital technologies to improve TB care remains limited. More studies of better
quality are needed to determine how such technologies can enhance programme performance
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