34 research outputs found

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Intronic ATTTC repeat expansions in STARD7 in familial adult myoclonic epilepsy linked to chromosome 2

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    Familial Adult Myoclonic Epilepsy (FAME) is characterised by cortical myoclonic tremor usually from the second decade of life and overt myoclonic or generalised tonic-clonic seizures. Four independent loci have been implicated in FAME on chromosomes (chr) 2, 3, 5 and 8. Using whole genome sequencing and repeat primed PCR, we provide evidence that chr2-linked FAME (FAME2) is caused by an expansion of an ATTTC pentamer within the first intron of STARD7. The ATTTC expansions segregate in 158/158 individuals typically affected by FAME from 22 pedigrees including 16 previously reported families recruited worldwide. RNA sequencing from patient derived fibroblasts shows no accumulation of the AUUUU or AUUUC repeat sequences and STARD7 gene expression is not affected. These data, in combination with other genes bearing similar mutations that have been implicated in FAME, suggest ATTTC expansions may cause this disorder, irrespective of the genomic locus involvedSupplementary Information: Supplementary Data 1; Supplementary Data 2; Reporting Summary.NHMRC; Women’s and Children’s Hospital Research Foundation; Muir Maxwell Trust; Epilepsy Society; The European Fund for Regional Development; The province of Friesland, Dystonia Medical Research Foundation; Stichting Wetenschapsfonds Dystonie Vereniging; Fonds Psychische Gezondheid; Phelps Stichting; The Italian Ministry of Health; Istituto Superiore di Sanità, Italy; Undiagnosed Disease Network Italy; The Fondation maladies rares, University Hospital Essen and UK Department of Health’s NIHR.https://www.nature.com/ncommspm2020Neurolog

    Genetic localisation and molecular characterisation of genes for inherited ataxias / Kathryn Louise Friend.

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    Copy of author's previously published work inserted.Bibliography: leaves 193-216.ix, 268 leaves : ill. ; 30 cm.Thesis which examines in detail the genetics of congental ataxias, and early and late onset ataxias.Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 200

    Study protocol for the Integra Initiative to assess the benefits and costs of integrating sexual and reproductive health and HIV services in Kenya and Swaziland.

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    BACKGROUND: In sub-Saharan Africa (SSA) there are strong arguments for the provision of integrated sexual and reproductive health (SRH) and HIV services. Most HIV transmissions are sexually transmitted or associated with pregnancy, childbirth, and breastfeeding. Many of the behaviours that prevent HIV transmission also prevent sexually transmitted infections and unintended pregnancies. There is potential for integration to increase the coverage of HIV services, as individuals who use SRH services can benefit from HIV services and vice-versa, as well as increase cost-savings. However, there is a dearth of empirical evidence on effective models for integrating HIV/SRH services. The need for robust evidence led a consortium of three organizations - International Planned Parenthood Federation, Population Council and the London School of Hygiene & Tropical Medicine - to design/implement the Integra Initiative. Integra seeks to generate rigorous evidence on the feasibility, effectiveness, cost and impact of different models for delivering integrated HIV/SRH services in high and medium HIV prevalence settings in SSA. METHODS/DESIGN: A quasi-experimental study will be conducted in government clinics in Kenya and Swaziland - assigned into intervention/comparison groups. Two models of service delivery are investigated: integrating HIV care/treatment into 1) family planning and 2) postnatal care. A full economic-costing will be used to assess the costs of different components of service provision, and the determinants of variations in unit costs across facilities/service models. Health facility assessments will be conducted at four time-periods to track changes in quality of care and utilization over time. A two-year cohort study of family planning/postnatal clients will assess the effect of integration on individual outcomes, including use of SRH services, HIV status (known/unknown) and pregnancy (planned/unintended). Household surveys within some of the study facilities' catchment areas will be conducted to profile users/non-users of integrated services and demand/receipt of integrated services, before-and-after the intervention. Qualitative research will be conducted to complement the quantitative component at different time points. Integra takes an embedded 'programme science' approach to maximize the uptake of findings into policy/practice. DISCUSSION: Integra addresses existing evidence gaps in the integration evaluation literature, building on the limited evidence from SSA and the expertise of its research partners. TRIAL REGISTRATION: Current Controlled Trials NCT01694862

    Lattice distortion in a zircon population and its effects on trace element mobility and U-Th-Pb isotope systematics: examples from the Lewisian Gneiss Complex, Northwest Scotland

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    Zircon is a key mineral in geochemical and geochronological studies in a range of geological settings as it is mechanically and chemically robust. However, distortion of its crystal lattice can facilitate enhanced diffusion of key elements such as U and Pb. Electron backscatter diffraction (EBSD) analysis of ninety-nine zircons from the Lewisian Gneiss Complex (LGC) of northwest Scotland has revealed five zircons with lattice distortion. The distortion can take the form of gradual bending of the lattice or division of the crystal into subgrains. Zircon lattices are distorted because of either post-crystallisation plastic distortion or growth defects. Three of the five distorted zircons, along with many of the undistorted zircons in the population, were analysed by ion microprobe to measure U and Pb isotopes, Ti and REEs. Comparison of Th/U ratio, 207Pb/206Pb age, REE profile and Ti concentration between zircons with and without lattice distortion suggests that the distortion is variably affecting the concentration of these trace elements and isotopes within single crystals, within samples and between localities. REE patterns vary heterogeneously, sometimes relatively depleted in heavy REEs or lacking a Eu anomaly. Ti-in-zircon thermometry records temperatures that were either low (~700 °C) or high (>900 °C) relative to undistorted zircons. One distorted zircon records apparent 207Pb/206Pb isotopic ages (−3.0 to +0.3 % discordance) in the range of ~2,420–2,450 Ma but this does not correlate with any previously dated tectonothermal event in the LGC. Two other distorted zircons give discordant ages of 2,331 ± 22 and 2,266 ± 40 Ma, defining a discordia lower intercept within error of a late amphibolite-facies tectonothermal event. This illustrates that Pb may be mobilised in distorted zircons at lower metamorphic grade than in undistorted zircons. These differences in trace element abundances and isotope systematics in distorted zircons relative to undistorted zircons are generally interpreted to have been facilitated by subgrain walls. Trace elements and isotopes would have moved from undistorted lattice into these subgrain walls as their chemical potential is modified due to the presence of the dislocations which make up the subgrain wall. Subgrain walls provided pathways for chemical exchange between crystal and surroundings. Only five per cent of zircons in this population have lattice distortion suggesting it will not have a major impact on zircon geochronology studies, particularly as three of the five distorted zircons are from strongly deformed rocks not normally sampled in such studies. However, this does suggest there may be a case for EBSD analysis of zircons prior to geochemical analysis when zircons from highly deformed rocks are to be investigated
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