378 research outputs found
The influence of nova nucleosynthesis on the chemical evolution of the Galaxy
We adopt up-to-date yields of 7Li, 13C, 15N from classical novae and use a
well tested model for the chemical evolution of the Milky Way in order to
predict the temporal evolution of these elemental species in the solar
neighborhood. In spite of major uncertainties due to our lack of knowledge of
metallicity effects on the final products of explosive nucleosynthesis in nova
outbursts, we find a satisfactory agreement between theoretical predictions and
observations for 7Li and 13C. On the contrary, 15N turns out to be overproduced
by about an order of magnitude.Comment: 8 pages, latex, 3 figures. To appear in "The Chemical Evolution of
the Milky Way: Stars versus Clusters", eds. F. Giovannelli and F. Matteucci
(Kluwer: Dordrecht
The effect of high dose antibiotic impregnated cement on rate of surgical site infection after hip hemiarthroplasty for fractured neck of femur : a protocol for a double-blind quasi randomised controlled trial
Background:
Mortality following hip hemiarthroplasty is in the range of 10-40% in the first year, with much attributed to post-operative complications. One such complication is surgical site infection (SSI), which at the start of this trial affected 4.68% of patients in the UK having this operation. Compared to SSI rates of elective hip surgery, at less than 1%, this figure is elevated. The aim of this quasi randomised controlled trial (RCT) is to determine if high dose antibiotic impregnated cement can reduce the SSI in patients at 12-months after hemiarthroplasty for intracapsular fractured neck of femur.
Methods:
848 patients with an intracapsular fractured neck of femur requiring a hip hemiarthroplasty are been recruited into this two-centre double-blind quasi RCT. Participants were recruited before surgery and quasi randomised to standard care or intervention group. Participants, statistician and outcome assessors were blind to treatment allocation throughout the study. The intervention consisted of high dose antibiotic impregnated cement consisting of 1 gram Clindamycin and 1 gram of Gentamicin. The primary outcome is Health Protection Agency (HPA) defined deep surgical site infection at 12 months. Secondary outcomes include HPA defined superficial surgical site infection at 30 days, 30 and 90-day mortality, length of hospital stay, critical care stay, and complications.
Discussion:
Large randomised controlled trials assessing the effectiveness of a surgical intervention are uncommon, particularly in the speciality of orthopaedics. The results from this trial will inform evidence-based recommendations for antibiotic impregnated cement in the management of patients with a fractured neck of femur undergoing a hip hemiarthroplasty. If high dose antibiotic impregnated cement is found to be an effective intervention, implementation into clinical practice could improve long-term outcomes for patients undergoing hip hemiarthroplasty
The relationship between sensory sensitivity and autistic traits in the general population.
Individuals with Autism Spectrum Disorders (ASDs) tend to have sensory processing difficulties (Baranek et al. in J Child Psychol Psychiatry 47:591–601, 2006). These difficulties include over- and under-responsiveness to sensory stimuli, and problems modulating sensory input (Ben-Sasson et al. in J Autism Dev Disorders 39:1–11, 2009). As those with ASD exist at the extreme end of a continuum of autistic traits that is also evident in the general population, we investigated the link between ASD and sensory sensitivity in the general population by administering two questionnaires online to 212 adult participants. Results showed a highly significant positive correlation (r = .775, p < .001) between number of autistic traits and the frequency of sensory processing problems. These data suggest a strong link between sensory processing and autistic traits in the general population, which in turn potentially implicates sensory processing problems in social interaction difficulties
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Sensory over-responsivity: parent report, direct assessment measures, and neural architecture
BACKGROUND:
Sensory processing difficulties are common across neurodevelopmental disorders. Thus, reliable measures are needed to understand the biological underpinnings of these differences. This study aimed to define a scoring methodology specific to auditory (AOR) and tactile (TOR) over-responsivity. Second, in a pilot cohort using MRI Diffusion Tensor Imaging, we performed a proof of concept study of whether children with AOR showed measurable differences in their white matter integrity.
METHODS:
This study included children with AOR and TOR from a mixed neurodevelopmental disorder cohort including autism and sensory processing dysfunction (n = 176) as well as neurotypical children (n = 128). We established cohorts based on sensory over-responsivity using parent report (Short Sensory Profile (SSP)) and direct assessment (Sensory Processing-Three Dimensions: Assessment (SP-3D:A)) measures. With a subset of the children (n = 39), group comparisons, based on AOR phenotype, were conducted comparing the white matter fractional anisotropy in 23 regions of interest.
RESULTS:
Using direct assessment, 31% of the children with neurodevelopmental disorders had AOR and 27% had TOR. The inter-test agreement between SSP and SP-3D:A for AOR was 65% and TOR was 50%. Children with AOR had three white matter tracts showing decreased fractional anisotropy relative to children without AOR.
CONCLUSIONS:
This study identified cut-off scores for AOR and TOR using the SSP parent report and SP-3D:A observation. A combination of questionnaire and direct observation measures should be used in clinical and research settings. The SSP parent report and SP-3D:A direct observation ratings overlapped moderately for sensory related behaviors. Based on these preliminary structural neuroimaging results, we suggest a putative neural network may contribute to AOR
Dynamics of dental evolution in ornithopod dinosaurs.
Ornithopods were key herbivorous dinosaurs in Mesozoic terrestrial ecosystems, with a variety of tooth morphologies. Several clades, especially the 'duck-billed' hadrosaurids, became hugely diverse and abundant almost worldwide. Yet their evolutionary dynamics have been disputed, particularly whether they diversified in response to events in plant evolution. Here we focus on their remarkable dietary adaptations, using tooth and jaw characters to examine changes in dental disparity and evolutionary rate. Ornithopods explored different areas of dental morphospace throughout their evolution, showing a long-term expansion. There were four major evolutionary rate increases, the first among basal iguanodontians in the Middle-Late Jurassic, and the three others among the Hadrosauridae, above and below the split of their two major clades, in the middle of the Late Cretaceous. These evolutionary bursts do not correspond to times of plant diversification, including the radiation of the flowering plants, and suggest that dental innovation rather than coevolution with major plant clades was a major driver in ornithopod evolution
Developing a digital intervention for cancer survivors: an evidence-, theory- and person-based approach
This paper illustrates a rigorous approach to developing digital interventions using an evidence-, theory- and person-based approach. Intervention planning included a rapid scoping review which identified cancer survivors’ needs, including barriers and facilitators to intervention success. Review evidence (N=49 papers) informed the intervention’s Guiding Principles, theory-based behavioural analysis and logic model. The intervention was optimised based on feedback on a prototype intervention through interviews (N=96) with cancer survivors and focus groups with NHS staff and cancer charity workers (N=31). Interviews with cancer survivors highlighted barriers to engagement, such as concerns about physical activity worsening fatigue. Focus groups highlighted concerns about support appointment length and how to support distressed participants. Feedback informed intervention modifications, to maximise acceptability, feasibility and likelihood of behaviour change. Our systematic method for understanding user views enabled us to anticipate and address important barriers to engagement. This methodology may be useful to others developing digital interventions
Re-branding Abu Dhabi: From oil giant to energy titan
This article presents a case study of Abu Dhabi\u27s \u27energy re-branding\u27 since 2005 when it declared its intention to transform itself from an oil exporter to a total energy giant that also embraces alternative (renewable and nuclear) energy. The first part of the article identifies the benefits of this policy for Abu Dhabi\u27s external diplomacy but argues that the real driver is the emirate\u27s domestic gas shortage and its effects on economic diversification and political legitimacy. The second part of the article discusses the motivations and interactions of local and foreign agents by focusing on the implementation of alternative energy platforms. It therefore provides a rare glimpse of the policy-making process in Abu Dhabi. The final part of the article examines the extent to which energy re-branding may be linked to a process by the government to reiterate, reinterpret and repudiate Emirati identity in order to enhance regime legitimacy in the twenty-first century. © 2012 Macmillan Publishers Ltd
Active Mile Briefing: Evidence And Policy Summary
Active mile initiatives can be defined as initiatives that support pupils to be active during the school day by providing regular opportunities for them to move around a marked route for a dedicated period of time (for example 15 minutes) and at a self-directed pace. It is thought that if moving continuously for this amount of time, most children will accumulate the equivalent distance of approximately one mile. As such, they have been termed as active mile initiatives. Active mile initiatives have gained in popularity and momentum over recent years. Whilst there is much evidence surrounding the health benefits of physical activity for children and young people, there is currently limited peer-reviewed high-quality evaluation and/or research which has focussed specifically on the effectiveness and cost-effectiveness of active mile initiatives. Furthermore, active mile initiatives have predominantly focused on primary schools, therefore there is limited research and/or information on their delivery with other age groups and/or settings such as nurseries and secondary schools. However, many of the principles are equally valid, for example they require no specialised equipment or resources. The evidence base surrounding active mile initiatives is evolving, and further research is needed to be able to draw firm conclusions. However, the evidence reviewed in this document indicates that active mile initiatives: • are intuitively appealing to schools as a means of providing regular physical activity and have high levels of acceptability among teachers and pupils • provide a simple physical activity opportunity for pupils which is suitable for all ages and are fully inclusive • can make a meaningful contribution to the in-school delivery of 30 active minutes and the Chief Medical Officer’s recommendation of an average of at least 60 minutes of physical activity each day across the week • can contribute to improvements in children’s health and wellbeing if implemented as part of a whole school approach to physical activity • should provide an additional opportunity to be active during the school day, they are not equivalent to and should not replace Physical Education (PE) This briefing accompanies, and should be used alongside, Implementing active mile initiatives in primary schools and Practice examples of active mile initiatives in schools
Active Mile Briefing: Evidence And Policy Summary
Active mile initiatives can be defined as initiatives that support pupils to be active during the school day by providing regular opportunities for them to move around a marked route for a dedicated period of time (for example 15 minutes) and at a self-directed pace. It is thought that if moving continuously for this amount of time, most children will accumulate the equivalent distance of approximately one mile. As such, they have been termed as active mile initiatives. Active mile initiatives have gained in popularity and momentum over recent years. Whilst there is much evidence surrounding the health benefits of physical activity for children and young people, there is currently limited peer-reviewed high-quality evaluation and/or research which has focussed specifically on the effectiveness and cost-effectiveness of active mile initiatives. Furthermore, active mile initiatives have predominantly focused on primary schools, therefore there is limited research and/or information on their delivery with other age groups and/or settings such as nurseries and secondary schools. However, many of the principles are equally valid, for example they require no specialised equipment or resources. The evidence base surrounding active mile initiatives is evolving, and further research is needed to be able to draw firm conclusions. However, the evidence reviewed in this document indicates that active mile initiatives: • are intuitively appealing to schools as a means of providing regular physical activity and have high levels of acceptability among teachers and pupils • provide a simple physical activity opportunity for pupils which is suitable for all ages and are fully inclusive • can make a meaningful contribution to the in-school delivery of 30 active minutes and the Chief Medical Officer’s recommendation of an average of at least 60 minutes of physical activity each day across the week • can contribute to improvements in children’s health and wellbeing if implemented as part of a whole school approach to physical activity • should provide an additional opportunity to be active during the school day, they are not equivalent to and should not replace Physical Education (PE) This briefing accompanies, and should be used alongside, Implementing active mile initiatives in primary schools and Practice examples of active mile initiatives in schools
Functional Characterization of Aquaporin-4 Specific T Cells: Towards a Model for Neuromyelitis Optica
Antibodies to the water channel protein aquaporin-4 (AQP4), which is expressed in astrocytic endfeet at the blood brain barrier, have been identified in the serum of Neuromyelitis optica (NMO) patients and are believed to induce damage to astrocytes. However, AQP4 specific T helper cell responses that are required for the generation of anti-AQP4 antibodies and most likely also for the formation of intraparenchymal CNS lesions have not been characterized. specific T cells were present in the natural T cell repertoire of wild type C57BL/6 mice and T cell lines were raised. However, active immunization with these AQP4 peptides did not induce signs of spinal cord disease. Rather, sensitization with AQP4 peptides resulted in production of IFN-γ, but also IL-5 and IL-10 by antigen-specific T cells. Consistent with this cytokine profile, the AQP4 specific antibody response upon immunization with full length AQP4 included IgG1 and IgG2, which are associated with a mixed Th2/Th1 T cell response. restricted AQP4 specific T cell epitopes will allow us to investigate how AQP4 specific autoimmune reactions are regulated and to establish faithful mouse models of NMO that include both cellular and humoral responses against AQP4
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