13 research outputs found

    Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development.

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    BACKGROUND: We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. RESULTS: The genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. CONCLUSIONS: Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    The Santonian stage and substages

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    The recognition of the Coniacian-Santonian boundary is easy with good correlation of macro- and microfossil evidence. The Santonian Working Group (SWG) recommends the lowest occurrence of Cladoceramus undulatoplicatus (Roemer) as the marker for the Coniacian-Santonian boundary. As yet, the SWG cannot make a formal proposal for a Boundary Stratotype Section, because the biostratigraphy must be better known and integrated first. Three candidates for Boundary Stratotype Section, Olazagutia Quarry (Navarra, Spain), Seaford Head (Sussex, England) and Ten Mile Creek (Dallas, Texas, USA) were selected for further decision. To achieve a useful subdivision of the Santonian into substages a better understanding of taxa ranges and correlation through different biogeographic realms is needed. Formal proposals for subdivision would be premature at present, but a three-fold division is favoured

    Speaking up about bullying and harassment in healthcare: reflections following the introduction of an innovative “speak up” role in NHS England

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    Healthcare organisations reap significant benefits when workers’ concerns are adequately listened and responded to, including improved patient safety, reduced costs and improved staff experience. Although many concerns are dealt with satisfactorily, compelling evidence suggests that problems of silence (where employees do not speak up) and deafness (where organisations do not hear concerns or act) remain pervasive worldwide. In the English National Health Service (NHS) the response to these problems includes numerous policy initiatives and the introduction in 2016 of the “Freedom to Speak Up Guardian” (FTSUG) role. This globally unique role is described as potentially leading to huge improvements in the way staff concerns are handled and responded to leading to improvements in organisational learning and patient safety. Following their introduction thousands of NHS staff have already spoken up via FTSUGs. The majority of FTSUGs time is spent on bullying and harassment concerns, rather than direct patient safety concerns, which appears to have confounded FTSUGs’ and others’ expectations. This chapter opens by describing the background to the development of the FTSUG role. We then outline the literature on bullying and harassment; its shocking prevalence within healthcare workplaces and the damaging consequences of bullying borne by organisations and individual staff and patients. We also discuss our analysis of semi-structured interviews (n = 87) undertaken with FTSUGs, which illustrates the realities of dealing with colleagues’ concerns about bullying and harassment and how these realities are often overlooked in national, regional and local workplace guidance and training materials currently available to support the implementation of the role

    Tantalum-modified Stellite 6 thick coatings:microstructure and mechanical performance

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    <p>Thick Co-based coatings with different contents of tantalum were prepared by simultaneous powder feeding laser cladding technique on 304 stainless steel substrate, with the Ta wt% being 0, 2, 7 and 12. Laser processing was carried out with a continuous 3.3 kW Yt:YAG fiber laser. Microstructural observations were executed using scanning electron microscopy, energy dispersive X-ray spectroscopy analysis, and transmission electron microscopy. Observations indicated that, with an increase in the Ta contents, the Ta-rich MC-type carbides were formed in interdendritic regions. Also, hexagonal M7C3-type carbides were formed instead of orthorhombic M7C3-type carbides. The orientation relationships between different phases and the matrix were determined by electron diffraction. Mechanical properties were determined using microhardness measurement at room temperature and wear resistance measurement at room and elevated (500 A degrees C) temperatures. The research demonstrated that alloying any amount of tantalum, in spite of increasing the microhardness, could be detrimental for increasing the wear resistance of Stellite 6, both at room and elevated temperatures. The relationship between microstructure and mechanical properties is explained.</p>
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