46 research outputs found

    A massive core for a cluster of galaxies at a redshift of 4.3

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    Massive galaxy clusters have been found that date to times as early as three billion years after the Big Bang, containing stars that formed at even earlier epochs1,2,3. The high-redshift progenitors of these galaxy clusters—termed ‘protoclusters’—can be identified in cosmological simulations that have the highest overdensities (greater-than-average densities) of dark matter4,5,6. Protoclusters are expected to contain extremely massive galaxies that can be observed as luminous starbursts7. However, recent detections of possible protoclusters hosting such starbursts8,9,10,11 do not support the kind of rapid cluster-core formation expected from simulations12: the structures observed contain only a handful of starbursting galaxies spread throughout a broad region, with poor evidence for eventual collapse into a protocluster. Here we report observations of carbon monoxide and ionized carbon emission from the source SPT2349-56. We find that this source consists of at least 14 gas-rich galaxies, all lying at redshifts of 4.31. We demonstrate that each of these galaxies is forming stars between 50 and 1,000 times more quickly than our own Milky Way, and that all are located within a projected region that is only around 130 kiloparsecs in diameter. This galaxy surface density is more than ten times the average blank-field value (integrated over all redshifts), and more than 1,000 times the average field volume density. The velocity dispersion (approximately 410 kilometres per second) of these galaxies and the enormous gas and star-formation densities suggest that this system represents the core of a cluster of galaxies that was already at an advanced stage of formation when the Universe was only 1.4 billion years old. A comparison with other known protoclusters at high redshifts shows that SPT2349-56 could be building one of the most massive structures in the Universe today

    A Research Agenda for Helminth Diseases of Humans: Basic Research and Enabling Technologies to Support Control and Elimination of Helminthiases

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    Successful and sustainable intervention against human helminthiases depends on optimal utilisation of available control measures and development of new tools and strategies, as well as an understanding of the evolutionary implications of prolonged intervention on parasite populations and those of their hosts and vectors. This will depend largely on updated knowledge of relevant and fundamental parasite biology. There is a need, therefore, to exploit and apply new knowledge and techniques in order to make significant and novel gains in combating helminthiases and supporting the sustainability of current and successful mass drug administration (MDA) programmes. Among the fields of basic research that are likely to yield improved control tools, the Disease Reference Group on Helminth Infections (DRG4) has identified four broad areas that stand out as central to the development of the next generation of helminth control measures: 1) parasite genetics, genomics, and functional genomics; 2) parasite immunology; 3) (vertebrate) host–parasite interactions and immunopathology; and 4) (invertebrate) host–parasite interactions and transmission biology. The DRG4 was established in 2009 by the Special Programme for Research and Training in Tropical Diseases (TDR). The Group was given the mandate to undertake a comprehensive review of recent advances in helminthiases research in order to identify notable gaps and highlight priority areas. This paper summarises recent advances and discusses challenges in the investigation of the fundamental biology of those helminth parasites under the DRG4 Group's remit according to the identified priorities, and presents a research and development agenda for basic parasite research and enabling technologies that will help support control and elimination efforts against human helminthiases

    A systematic review of mental health outcome measures for young people aged 12 to 25 years

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    New quality regulations versus established nursing home practice: a qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Western governments have initiated reforms to improve the quality of care for nursing home residents. Most of these reforms encompass the use of regulations and national quality indicators. In the Norwegian context, these regulations comprise two pages of text that are easy to read and understand. They focus particularly on residents’ rights to plan their day-to-day life in nursing homes. However, the research literature indicates that the implementation of the new regulations, particularly if they aim to change nursing practice, is extremely challenging. The aim of this study was to further explore and describe nursing practice to gain a deeper understanding of why it is so hard to implement the new regulations.</p> <p>Methods</p> <p>For this qualitative study, an ethnographic design was chosen to explore and describe nursing practice. Fieldwork was conducted in two nursing homes. In total, 45 nurses and nursing aides were included in participant observation, and 10 were interviewed at the end of the field study.</p> <p>Results</p> <p>Findings indicate that the staff knew little about the new quality regulations, and that the quality of their work was guided by other factors rooted in their nursing practice. Further analyses revealed that the staff appeared to be committed to daily routines and also that they always seemed to know what to do. Having routines and always knowing what to do mutually strengthen and enhance each other, and together they form a powerful force that makes daily nursing care a taken-for-granted activity.</p> <p>Conclusion</p> <p>New regulations are challenging to implement because nursing practices are so strongly embedded. Improving practice requires systematic and deeply rooted practical change in everyday action and thinking.</p
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