578 research outputs found

    The history of African village chickens: an archaeological and molecular perspective

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    The history of the introduction and dispersal of village chickens across the African continent is a subject of intense debate and speculation among scholars. Here, we synthesize and summarise the current scientific genetic and nongenetic knowledge in relation to the history of the species on the continent. Sociocultural, linguistic, archaeological and historic data all suggest a complex history for the species in Africa, characterized by multiple maritime and/or terrestrial introductions over time and several dispersal routes towards and within Africa. Molecular genetics information supports these observations and in addition suggests possible Asian centers of origin for African domestic chickens, including South Asia and Island Southeast Asia. However, both sets of data were until now too limited in their geographic scope, both within Africa and in comparison with chickens from Asia, to unravel the history of the species in detail. We anticipate that further continent-wide studies combining archaeological, ancient and/or modern genetic information may shed new insights on the history of the species. These will contribute to a deeper understanding of the history of trading networks and human interactions within Africa and between African and Asian societies, at the root of the development and expansion of African civilizations

    Effectiveness and micro-costing of the KiVa school-based bullying prevention programme in Wales: study protocol for a pragmatic definitive parallel group cluster randomised controlled trial

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    This is the final version of the article. Available from the publisher via the DOI in this record.BACKGROUND: Bullying refers to verbal, physical or psychological aggression repeated over time that is intended to cause harm or distress to the victims who are unable to defend themselves. It is a key public health priority owing to its widespread prevalence in schools and harmful short- and long-term effects on victims' well-being. There is a need to strengthen the evidence base by testing innovative approaches to preventing bullying. KiVa is a school-based bullying prevention programme with universal and indicated elements and an emphasis on changing bystander behaviour. It achieved promising results in a large trial in Finland, and now requires testing in other countries. This paper describes the protocol for a cluster randomised controlled trial (RCT) of KiVa in Wales. METHODS/DESIGN: The study uses a two-arm waitlist control pragmatic definitive parallel group cluster RCT design with an embedded process evaluation and calculation of unit cost. Participating schools will be randomised a using a 1:1 ratio to KiVa plus usual provision (intervention group) or usual provision only (control group). The trial has one primary outcome, child self-reported victimisation from bullying, dichotomised as 'victimised' (bullied at least twice a month in the last couple of months) versus 'not victimised'. Secondary outcomes are: bullying perpetration; aspects of child social and emotional well-being (including emotional problems, conduct, peer relations, prosocial behaviour); and school attendance. Follow-up is at 12 months post-baseline. Implementation fidelity is measured through teacher-completed lesson records and independent school-wide observation. A micro-costing analysis will determine the costs of implementing KiVa, including recurrent and non-recurrent unit costs. Factors related to the scalability of the programme will be examined in interviews with head teachers and focus groups with key stakeholders in the implementation of school-based bullying interventions. DISCUSSION: The results from this trial will provide evidence on whether the KiVa programme is transportable from Finland to Wales in terms of effectiveness and implementation. It will provide information about the costs of delivery and generate insights into factors related to the scalability of the programme. TRIAL REGISTRATION: Current Controlled Trials ISRCTN23999021 Date 10-6-13.BIG Lottery Wales (REF: B/l/1/010430196) is funding the costs of the trial, including recruitment conferences, provision of programme resources for schools, translation of resources into Welsh, support and feedback sessions, and central organisational meetings. The design, management, statistical analysis and dissemination of the trial are fully independent of the BIG Lottery and KiVa Finland. The programme is delivered by teachers and other school staff during school hours and no supply costs are provided to schools for staff training

    Cardiovascular magnetic resonance of myocardial infarction after blunt chest trauma: a heartbreaking soccer-shot

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    Cardiac injury occasionally occurs as a result of blunt chest trauma. Most cardiac complications in chest trauma are due to myocardial contusion rather than direct damage to the coronary arteries. However, traumatic coronary injury has been reported, and a variety of underlying pathophysiological mechanisms have been proposed. We present a 26 year old patient presenting with an acute coronary syndrome as a consequence of a soccer-shot impact to the chest. CMR showed apical inferior infarction, as well as multiple small septal lesions which were presumed to have resulted from embolization. The culprit lesion was a proximal 75% LAD stenosis with a prominent plaque-rupture and thrombus-formation, and the distal LAD was occluded by thromboembolic material

    Succinate in dystrophic white matter: A proton magnetic resonance spectroscopy finding characteristic for complex II deficiency

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    A deficiency of succinate dehydrogenase is a rare cause of mitochondrial encephalomyopathy. Three patients, 2 sisters and I boy from an unrelated family, presented with symptoms and magnetic resonance imaging signs of leukoencephalopathy. Localized proton magnetic resonance spectroscopy indicated a prominent singlet at 2.40ppm in cerebral and cerebellar white matter not present in gray matter or basal ganglia. The signal was also elevated in cerebrospinal fluid and could be identified as originating from the two equivalent methylene groups of succinate. Subsequently, an isolated deficiency of complex II (succinate:ubiquinone oxidoreductase) was demonstrated in 2 patients in muscle and fibroblasts. One of the sisters died at the age of 18 months. Postmortem examination showed the neuropathological characteristics of Leigh syndrome. Her younger sister, now 12 months old, is also severely affected; the boy, now 6 years old, follows a Milder, fluctuating clinical course. Magnetic resonance spectroscopy provides a characteristic pattern in succinate dehydrogenase deficiency

    Multicenter study of hypoxemia prevalence and quality of oxygen treatment for hospitalized Malawian children

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    Although hypoxemic children have high mortality, little is known about hypoxemia prevalence and oxygen administration in African hospitals. We aimed to determine the hypoxemia prevalence and quality of oxygen treatment by local clinicians for hospitalized Malawian children

    Effects of Noise on Ecological Invasion Processes: Bacteriophage-mediated Competition in Bacteria

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    Pathogen-mediated competition, through which an invasive species carrying and transmitting a pathogen can be a superior competitor to a more vulnerable resident species, is one of the principle driving forces influencing biodiversity in nature. Using an experimental system of bacteriophage-mediated competition in bacterial populations and a deterministic model, we have shown in [Joo et al 2005] that the competitive advantage conferred by the phage depends only on the relative phage pathology and is independent of the initial phage concentration and other phage and host parameters such as the infection-causing contact rate, the spontaneous and infection-induced lysis rates, and the phage burst size. Here we investigate the effects of stochastic fluctuations on bacterial invasion facilitated by bacteriophage, and examine the validity of the deterministic approach. We use both numerical and analytical methods of stochastic processes to identify the source of noise and assess its magnitude. We show that the conclusions obtained from the deterministic model are robust against stochastic fluctuations, yet deviations become prominently large when the phage are more pathological to the invading bacterial strain.Comment: 39 pages, 7 figure

    A comparison of the effectiveness of cognitive behavioural interventions based on delivery features for elevated symptoms of depression in adolescents: A systematic review

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    This is the final version. Available on open access from Wiley via the DOI in this record. Data availability statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.Background Depression is a public health problem and common amongst adolescents. Cognitive behavioural therapy (CBT) is widely used to treat adolescent depression but existing research does not provide clear conclusions regarding the relative effectiveness of different delivery modalities. Objectives The primary aim is to estimate the relative efficacy of different modes of CBT delivery compared with each other and control conditions for reducing depressive symptoms in adolescents. The secondary aim is to compare the different modes of delivery with regard to intervention completion/attrition (a proxy for intervention acceptability). Search Methods The Cochrane Depression, Anxiety and Neurosis Clinical Trials Register was searched in April 2020. MEDLINE, PsycInfo, EMBASE, four other electronic databases, the CENTRAL trial registry, Google Scholar and Google were searched in November 2020, together with reference checking, citation searching and hand-searching of two databases. Selection Criteria Randomised controlled trials (RCTs) of CBT interventions (irrespective of delivery mode) to reduce symptoms of depression in young people aged 10–19 years with clinically relevant symptoms or diagnosis of depression were included. Data Collection and Analysis Screening and data extraction were completed by two authors independently, with discrepancies addressed by a third author. CBT interventions were categorised as follows: group CBT, individual CBT, remote CBT, guided self-help, and unguided self-help. Effect on depressive symptom score was estimated across validated self-report measures using Hedges' g standardised mean difference. Acceptability was estimated based on loss to follow-up as an odds ratio. Treatment rankings were developed using the surface under the cumulative ranking curve (SUCRA). Pairwise meta-analyses were conducted using random effects models where there were two or more head-to-head trials. Network analyses were conducted using random effects models. Main Results Sixty-eight studies were included in the review. The mean age of participants ranged from 10 to 19.5 years, and on average 60% of participants were female. The majority of studies were conducted in schools (28) or universities (6); other settings included primary care, clinical settings and the home. The number of CBT sessions ranged from 1 to 16, the frequency of delivery from once every 2 weeks to twice a week and the duration of each session from 20 min to 2 h. The risk of bias was low across all domains for 23 studies, 24 studies had some concerns and the remaining 21 were assessed to be at high risk of bias. Sixty-two RCTs (representing 6435 participants) were included in the pairwise and network meta-analyses for post-intervention depressive symptom score at post-intervention. All pre-specified treatment and control categories were represented by at least one RCT. Although most CBT approaches, except remote CBT, demonstrated superiority over no intervention, no approaches performed clearly better than or equivalent to another. The highest and lowest ranking interventions were guided self-help (SUCRA 83%) and unguided self-help (SUCRA 51%), respectively (very low certainty in treatment ranking). Nineteen RCTs (3260 participants) were included in the pairwise and network meta-analyses for 6 to 12 month follow-up depressive symptom score. Neither guided self-help nor remote CBT were evaluated in the RCTs for this time point. Effects were generally attenuated for 6- to 12-month outcomes compared to posttest. No interventions demonstrated superiority to no intervention, although unguided self-help and group CBT both demonstrated superiority compared to TAU. No CBT approach demonstrated clear superiority over another. The highest and lowest ranking approaches were unguided self-help and individual CBT, respectively. Sixty-two RCTs (7347 participants) were included in the pairwise and network meta-analyses for intervention acceptability. All pre-specified treatment and control categories were represented by at least one RCT. Although point estimates tended to favour no intervention, no active treatments were clearly inferior. No CBT approach demonstrated clear superiority over another. The highest and lowest ranking active interventions were individual CBT and group CBT respectively. Pairwise meta-analytic findings were similar to those of the network meta-analysis for all analyses. There may be age-based subgroup effects on post-intervention depressive symptoms. Using the no intervention control group as the reference, the magnitudes of effects appear to be larger for the oldest age categories compared to the other subgroups for each given comparison. However, they were generally less precise and formal testing only indicated a significant difference for group CBT. Findings were robust to pre-specified sensitivity analyses separating out the type of placebo and excluding cluster-RCTs, as well as an additional analysis excluding studies where we had imputed standard deviations. Authors' Conclusions At posttreatment, all active treatments (group CBT, individual CBT, guided self-help, and unguided self-help) except for remote CBT were more effective than no treatment. Guided self-help was the most highly ranked intervention but only evaluated in trials with the oldest adolescents (16–19 years). Moreover, the studies of guided self-help vary in the type and amount of therapist support provided and longer-term results are needed to determine whether effects persist. The magnitude of effects was generally attenuated for 6- to 12-month outcomes. Although unguided self-help was the lowest-ranked active intervention at post-intervention, it was the highest ranked at follow-up. This suggests the need for further research into whether interventions with self-directed elements enable young people to maintain effects by continuing or revisiting the intervention independently, and whether therapist support would improve long-term outcomes. There was no clear evidence that any active treatments were more acceptable to participants than any others. The relative effectiveness of intervention delivery modes must be taken into account in the context of the needs and preferences of individual young people, particularly as the differences between effect sizes were relatively small. Further research into the type and amount of therapist support that is most acceptable to young people and most cost-effective would be particularly useful.Jacobs FoundationNational Institute for Health and Care Research (NIHR

    M1 Resonances in Unstable Magic Nuclei

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    Within a microscopic approach which takes into account RPA configurations, the single-particle continuum and more complex 1p1h⊗phonon1p1h\otimes phonon configurations isoscalar and isovector M1 excitations for the unstable nuclei 56,78{56,78}Ni and 100,132{100,132}Sn are calculated. For comparison, the experimentally known M1 excitations in 40{40}Ca and 208^{208}Pb have also been calculated. In the latter nuclei good agreement in the centroid energy, the total transition strength and the resonance width is obtained. With the same parameters we predict the magnetic excitations for the unstable nuclei. The strength is sufficiently concentrated to be measurable in radioactive beam experiments. New features are found for the very neutron rich nucleus 78{78}Ni and the neutron deficient nucleus 100{100}Sn.Comment: 17 pages (LATEX), 12 figures (available from the authors), KFA-IKP(TH)-1993-0
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