815 research outputs found

    Earthworm genomes, genes and proteins: the (re)discovery of Darwin's worms

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    Small incremental biological change, winnowed by natural selection over geological time scales to produce large consequences, was Darwin's singular insight that revolutionized the life sciences. His publications after 1859, including the ‘earthworm book’, were all written to amplify and support the evolutionary theory presented in the Origin. Darwin was unable to provide a physical basis for the inheritance of favoured traits because of the absence of genetic knowledge that much later led to the ‘modern synthesis’. Mistaken though he was in advocating systemic ‘gemmules’ as agents of inheritance, Darwin was perceptive in seeking to underpin his core vision with concrete factors that both determine the nature of a trait in one generation and convey it to subsequent generations. This brief review evaluates the molecular genetic literature on earthworms published during the last decade, and casts light on the specific aspects of earthworm evolutionary biology that more or less engaged Darwin: (i) biogeography, (ii) species diversity, (iii) local adaptations and (iv) sensitivity. We predict that the current understanding will deepen with the announcement of a draft earthworm genome in Darwin's bicentenary year, 2009. Subsequently, the earthworm may be elevated from the status of a soil sentinel to that elusive entity, an ecologically relevant genetic model organism

    A short form of the Children’s Experiences of Dental Anxiety Measure (CEDAM) : validation and evaluation of the CEDAM-8

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    Background: The Children’s Experiences of Dental Anxiety Measure (CEDAM-14) is a child-centred measure of dental anxiety which assesses a range of behaviours, thoughts and feelings/physical symptoms related to dental anxiety. A short form of the CEDAM-14, which places less time burden on patients and clinicians, could promote the feasibility and applicability of the CEDAM in clinical settings. The aim of the study was to develop a short version of the CEDAM that can be used to assess children’s dental anxiety in clinical practice. Methods: A short version of the CEDAM was developed using a combination of item impact and regression methods. Measurement properties including floor/ceiling effects, variance, criterion validity, construct validity and internal consistency was calculated for the short form. Results: An eight-item CEDAM short form was developed (CEDAM-8) that had good psychometric properties, was significantly correlated with the CEDAM measure (r = 0.90; p < 0.01), had minimal floor and ceiling effects (3.5% and 1.2%, respectively) and was sensitive to change. Conclusion: The CEDAM-8 is a useful assessment tool for clinicians that is easy and quick to administer and could help to understand children’s experiences of dental anxiety and changes in anxiety over time and following intervention

    The celebrity entrepreneur on television: profile, politics and power

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    This article examines the rise of the ‘celebrity entrepreneur’ on television through the emergence of the ‘business entertainment format’ and considers the ways in which regular television exposure can be converted into political influence. Within television studies there has been a preoccupation in recent years with how lifestyle and reality formats work to transform ‘ordinary’ people into celebrities. As a result, the contribution of vocationally skilled business professionals to factual entertainment programming has gone almost unnoticed. This article draws on interviews with key media industry professionals and begins by looking at the construction of entrepreneurs as different types of television personalities and how discourses of work, skill and knowledge function in business shows. It then outlines how entrepreneurs can utilize their newly acquired televisual skills to cultivate a wider media profile and secure various forms of political access and influence. Integral to this is the centrality of public relations and media management agencies in shaping media discourses and developing the individual as a ‘brand identity’ that can be used to endorse a range of products or ideas. This has led to policy makers and politicians attempting to mobilize the media profile of celebrity entrepreneurs to reach out and connect with the public on business and enterprise-related issues

    Origins of the Ambient Solar Wind: Implications for Space Weather

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    The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress -- in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue connected with a 2016 ISSI workshop on "The Scientific Foundations of Space Weather." 44 pages, 9 figure

    Using a theoretically informed process evaluation alongside a trial to improve oral health for care home residents

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    BACKGROUND: Poor oral health is common among older adults residing in care homes impacting their diet, quality of life, self-esteem, general health and well-being. The care home setting is complex and many factors may affect the successful implementation of oral care interventions. Exploring these factors and their embedded context is key to understanding how and why interventions may or may not be successfully implemented within their intended setting. OBJECTIVES: This methodology paper describes the approach to a theoretically informed process evaluation alongside a pragmatic randomised controlled trial, so as to understand contextual factors, how the intervention was implemented and important elements that may influence the pathways to impact. MATERIALS AND METHODS: SENIOR is a pragmatic randomised controlled trial designed to improve the oral health of care home residents in the United Kingdom. The trial uses a complex intervention to promote and provide oral care for residents, including education and training for staff. RESULTS: An embedded, theoretically informed process evaluation, drawing on the PAHRIS framework and utilising a qualitative approach, will help to understand the important contextual factors within the care home that influence both the trial processes and the implementation of the intervention. CONCLUSION: Utilising an implementation framework as the basis for a theoretically informed process evaluation provides an approach that specifically focuses on the contextual factors that may influence and shape the pathways to impact a given complex intervention a priori, while also providing an understanding of how and why an intervention may be effective. This contrasts with the more common post hoc approach that only focuses on implementation after the empirical results have emerged

    Cryptic Eimeria genotypes are common across the southern but not northern hemisphere

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    The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩜0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere

    Semaphorin 3F signaling actively retains neutrophils at sites of inflammation

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    Neutrophilic inflammation is central to disease pathogenesis, for example, in chronic obstructive pulmonary disease, yet the mechanisms that retain neutrophils within tissues remain poorly understood. With emerging evidence that axon guidance factors can regulate myeloid recruitment and that neutrophils can regulate expression of a class 3 semaphorin, SEMA3F, we investigated the role of SEMA3F in inflammatory cell retention within inflamed tissues. We observed that neutrophils upregulate SEMA3F in response to proinflammatory mediators and following neutrophil recruitment to the inflamed lung. In both zebrafish tail injury and murine acute lung injury models of neutrophilic inflammation, overexpression of SEMA3F delayed inflammation resolution with slower neutrophil migratory speeds and retention of neutrophils within the tissues. Conversely, constitutive loss of sema3f accelerated egress of neutrophils from the tail injury site in fish, whereas neutrophil-specific deletion of Sema3f in mice resulted in more rapid neutrophil transit through the airways, and significantly reduced time to resolution of the neutrophilic response. Study of filamentous-actin (F-actin) subsequently showed that SEMA3F-mediated retention is associated with F-actin disassembly. In conclusion, SEMA3F signaling actively regulates neutrophil retention within the injured tissues with consequences for neutrophil clearance and inflammation resolution
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