449 research outputs found

    Improving Efficiency and Quality of the Children’s ASD Diagnostic Pathway: Lessons Learned from Practice

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    The ‘autism diagnosis crisis’ and long waiting times for assessment are as yet unresolved, leading to undue stress and limiting\ud access to effective support. There is therefore a significant need for evidence to support practitioners in the development of\ud efficient services, delivering acceptable waiting times and effectively meeting guideline standards. This study reports statistically\ud significant reductions in waiting times for autism diagnostic assessment following a children’s health service improvement\ud programme. The average wait between referral and first appointment reduced from 14.2 to 10.4 weeks (t(21) = 4.3,\ud p < 0.05) and between referral and diagnosis shared, reduced from 270 to 122.5 days, (t(20) = 5.5, p < 0.05). The proportion\ud of girls identified increased from 5.6 to 2.7:1. Methods reported include: local improvement action planning; evidence based\ud pathways; systematic clinical data gathering and a training plan. This is a highly significant finding for many health services\ud wrestling with the challenges of demand and capacity for autism diagnosis and assessment

    Atypical disengagement from faces and its modulation by the control of eye fixation in children with Autism Spectrum Disorder

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    By using the gap overlap task, we investigated disengagement from faces and objects in children (9–17 years old) with and without autism spectrum disorder (ASD) and its neurophysiological correlates. In typically developing (TD) children, faces elicited larger gap effect, an index of attentional engagement, and larger saccade-related event-related potentials (ERPs), compared to objects. In children with ASD, by contrast, neither gap effect nor ERPs differ between faces and objects. Follow-up experiments demonstrated that instructed fixation on the eyes induces larger gap effect for faces in children with ASD, whereas instructed fixation on the mouth can disrupt larger gap effect in TD children. These results suggest a critical role of eye fixation on attentional engagement to faces in both groups

    Massive stars as thermonuclear reactors and their explosions following core collapse

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    Nuclear reactions transform atomic nuclei inside stars. This is the process of stellar nucleosynthesis. The basic concepts of determining nuclear reaction rates inside stars are reviewed. How stars manage to burn their fuel so slowly most of the time are also considered. Stellar thermonuclear reactions involving protons in hydrostatic burning are discussed first. Then I discuss triple alpha reactions in the helium burning stage. Carbon and oxygen survive in red giant stars because of the nuclear structure of oxygen and neon. Further nuclear burning of carbon, neon, oxygen and silicon in quiescent conditions are discussed next. In the subsequent core-collapse phase, neutronization due to electron capture from the top of the Fermi sea in a degenerate core takes place. The expected signal of neutrinos from a nearby supernova is calculated. The supernova often explodes inside a dense circumstellar medium, which is established due to the progenitor star losing its outermost envelope in a stellar wind or mass transfer in a binary system. The nature of the circumstellar medium and the ejecta of the supernova and their dynamics are revealed by observations in the optical, IR, radio, and X-ray bands, and I discuss some of these observations and their interpretations.Comment: To be published in " Principles and Perspectives in Cosmochemistry" Lecture Notes on Kodai School on Synthesis of Elements in Stars; ed. by Aruna Goswami & Eswar Reddy, Springer Verlag, 2009. Contains 21 figure

    Artemisinin Inhibits Chloroplast Electron Transport Activity: Mode of Action

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    Artemisinin, a secondary metabolite produced in Artemisia plant species, besides having antimalarial properties is also phytotoxic. Although, the phytotoxic activity of the compound has been long recognized, no information is available on the mechanism of action of the compound on photosynthetic activity of the plant. In this report, we have evaluated the effect of artemisinin on photoelectron transport activity of chloroplast thylakoid membrane. The inhibitory effect of the compound, under in vitro condition, was pronounced in loosely and fully coupled thylakoids; being strong in the former. The extent of inhibition was drastically reduced in the presence of uncouplers like ammonium chloride or gramicidin; a characteristic feature described for energy transfer inhibitors. The compound, on the other hand, when applied to plants (in vivo), behaved as a potent inhibitor of photosynthetic electron transport. The major site of its action was identified to be the QB; the secondary quinone moiety of photosystemII complex. Analysis of photoreduction kinetics of para-benzoquinone and duroquinone suggest that the inhibition leads to formation of low pool of plastoquinol, which becomes limiting for electron flow through photosystemI. Further it was ascertained that the in vivo inhibitory effect appeared as a consequence of the formation of an unidentified artemisinin-metabolite rather than by the interaction of the compound per se. The putative metabolite of artemisinin is highly reactive in instituting the inhibition of photosynthetic electron flow eventually reducing the plant growth

    Integrated community case management in a peri-urban setting: a qualitative evaluation in Wakiso District, Uganda.

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    Integrated community case management (iCCM) strategies aim to reach poor communities by providing timely access to treatment for malaria, pneumonia and diarrhoea for children under 5 years of age. Community health workers, known as Village Health Teams (VHTs) in Uganda, have been shown to be effective in hard-to-reach, underserved areas, but there is little evidence to support iCCM as an appropriate strategy in non-rural contexts. This study aimed to inform future iCCM implementation by exploring caregiver and VHT member perceptions of the value and effectiveness of iCCM in peri-urban settings in Uganda.A qualitative evaluation was conducted in seven villages in Wakiso district, a rapidly urbanising area in central Uganda. Villages were purposively selected, spanning a range of peri-urban settlements experiencing rapid population change. In each village, rapid appraisal activities were undertaken separately with purposively selected caregivers (n = 85) and all iCCM-trained VHT members (n = 14), providing platforms for group discussions. Fifteen key informant interviews were also conducted with community leaders and VHT members. Thematic analysis was based on the 'Health Access Livelihoods Framework'.iCCM was perceived to facilitate timely treatment access and improve child health in peri-urban settings, often supplanting private clinics and traditional healers as first point of care. Relative to other health service providers, caregivers valued VHTs' free, proximal services, caring attitudes, perceived treatment quality, perceived competency and protocol use, and follow-up and referral services. VHT effectiveness was perceived to be restricted by inadequate diagnostics, limited newborn care, drug stockouts and VHT member absence - factors which drove utilisation of alternative providers. Low community engagement in VHT selection, lack of referral transport and poor availability of referral services also diminished perceived effectiveness. The iCCM strategy was widely perceived to result in economic savings and other livelihood benefits.In peri-urban areas, iCCM was perceived as an effective, well-utilised strategy, reflecting both VHT attributes and gaps in existing health services. Depending on health system resources and organisation, iCCM may be a useful transitional service delivery approach. Implementation in peri-urban areas should consider tailored community engagement strategies, adapted selection criteria, and assessment of population density to ensure sufficient coverage

    High-flux isobutanol production using engineered Escherichia coli: a bioreactor study with in situ product removal

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    Promising approaches to produce higher alcohols, e.g., isobutanol, using Escherichia coli have been developed with successful results. Here, we translated the isobutanol process from shake flasks to a 1-L bioreactor in order to characterize three E. coli strains. With in situ isobutanol removal from the bioreactor using gas stripping, the engineered E. coli strain (JCL260) produced more than 50 g/L in 72 h. In addition, the isobutanol production by the parental strain (JCL16) and the high isobutanol-tolerant mutant (SA481) were compared with JCL260. Interestingly, we found that the isobutanol-tolerant strain in fact produced worse than either JCL16 or JCL260. This result suggests that in situ product removal can properly overcome isobutanol toxicity in E. coli cultures. The isobutanol productivity was approximately twofold and the titer was 9% higher than n-butanol produced by Clostridium in a similar integrated system

    Indeterminacy of Reverse Engineering of Gene Regulatory Networks: The Curse of Gene Elasticity

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    Gene Regulatory Networks (GRNs) have become a major focus of interest in recent years. A number of reverse engineering approaches have been developed to help uncover the regulatory networks giving rise to the observed gene expression profiles. However, this is an overspecified problem due to the fact that more than one genotype (network wiring) can give rise to the same phenotype. We refer to this phenomenon as “gene elasticity.” In this work, we study the effect of this particular problem on the pure, data-driven inference of gene regulatory networks.We simulated a four-gene network in order to produce “data” (protein levels) that we use in lieu of real experimental data. We then optimized the network connections between the four genes with a view to obtain the original network that gave rise to the data. We did this for two different cases: one in which only the network connections were optimized and the other in which both the network connections as well as the kinetic parameters (given as reaction probabilities in our case) were estimated. We observed that multiple genotypes gave rise to very similar protein levels. Statistical experimentation indicates that it is impossible to differentiate between the different networks on the basis of both equilibrium as well as dynamic data.We show explicitly that reverse engineering of GRNs from pure expression data is an indeterminate problem. Our results suggest the unsuitability of an inferential, purely data-driven approach for the reverse engineering transcriptional networks in the case of gene regulatory networks displaying a certain level of complexity

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Search for the standard model Higgs boson at LEP

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