776 research outputs found

    A Sensory Bias Has Triggered the Evolution of Egg-Spots in Cichlid Fishes

    Get PDF
    Although, generally, the origin of sex-limited traits remains elusive, the sensory exploitation hypothesis provides an explanation for the evolution of male sexual signals. Anal fin egg-spots are such a male sexual signal and a key characteristic of the most species-rich group of cichlid fishes, the haplochromines. Males of about 1500 mouth-brooding species utilize these conspicuous egg-dummies during courtship – apparently to attract females and to maximize fertilization success. Here we test the hypothesis that the evolution of haplochromine egg-spots was triggered by a pre-existing bias for eggs or egg-like coloration. To this end, we performed mate-choice experiments in the basal haplochromine Pseudocrenilabrus multicolor, which manifests the plesiomorphic character-state of an egg-spot-less anal fin. Experiments using computer-animated photographs of males indeed revealed that females prefer images of males with virtual (‘in-silico’) egg-spots over images showing unaltered males. In addition, we tested for color preferences (outside a mating context) in a phylogenetically representative set of East African cichlids. We uncovered a strong preference for yellow, orange or reddish spots in all haplochromines tested and, importantly, also in most other species representing more basal lines. This pre-existing female sensory bias points towards high-quality (carotenoids-enriched) food suggesting that it is adaptive

    Protocol for the Foot in Juvenile Idiopathic Arthritis trial (FiJIA): a randomised controlled trial of an integrated foot care programme for foot problems in JIA

    Get PDF
    <b>Background</b>: Foot and ankle problems are a common but relatively neglected manifestation of juvenile idiopathic arthritis. Studies of medical and non-medical interventions have shown that clinical outcome measures can be improved. However existing data has been drawn from small non-randomised clinical studies of single interventions that appear to under-represent the adult population suffering from juvenile idiopathic arthritis. To date, no evidence of combined therapies or integrated care for juvenile idiopathic arthritis patients with foot and ankle problems exists. <b>Methods/design</b>: An exploratory phase II non-pharmacological randomised controlled trial where patients including young children, adolescents and adults with juvenile idiopathic arthritis and associated foot/ankle problems will be randomised to receive integrated podiatric care via a new foot care programme, or to receive standard podiatry care. Sixty patients (30 in each arm) including children, adolescents and adults diagnosed with juvenile idiopathic arthritis who satisfy the inclusion and exclusion criteria will be recruited from 2 outpatient centres of paediatric and adult rheumatology respectively. Participants will be randomised by process of minimisation using the Minim software package. The primary outcome measure is the foot related impairment measured by the Juvenile Arthritis Disability Index questionnaire's impairment domain at 6 and 12 months, with secondary outcomes including disease activity score, foot deformity score, active/limited foot joint counts, spatio-temporal and plantar-pressure gait parameters, health related quality of life and semi-quantitative ultrasonography score for inflammatory foot lesions. The new foot care programme will comprise rapid assessment and investigation, targeted treatment, with detailed outcome assessment and follow-up at minimum intervals of 3 months. Data will be collected at baseline, 6 months and 12 months from baseline. Intention to treat data analysis will be conducted. A full health economic evaluation will be conducted alongside the trial and will evaluate the cost effectiveness of the intervention. This will consider the cost per improvement in Juvenile Arthritis Disability Index, and cost per quality adjusted life year gained. In addition, a discrete choice experiment will elicit willingness to pay values and a cost benefit analysis will also be undertaken

    Quantum Computing

    Full text link
    Quantum mechanics---the theory describing the fundamental workings of nature---is famously counterintuitive: it predicts that a particle can be in two places at the same time, and that two remote particles can be inextricably and instantaneously linked. These predictions have been the topic of intense metaphysical debate ever since the theory's inception early last century. However, supreme predictive power combined with direct experimental observation of some of these unusual phenomena leave little doubt as to its fundamental correctness. In fact, without quantum mechanics we could not explain the workings of a laser, nor indeed how a fridge magnet operates. Over the last several decades quantum information science has emerged to seek answers to the question: can we gain some advantage by storing, transmitting and processing information encoded in systems that exhibit these unique quantum properties? Today it is understood that the answer is yes. Many research groups around the world are working towards one of the most ambitious goals humankind has ever embarked upon: a quantum computer that promises to exponentially improve computational power for particular tasks. A number of physical systems, spanning much of modern physics, are being developed for this task---ranging from single particles of light to superconducting circuits---and it is not yet clear which, if any, will ultimately prove successful. Here we describe the latest developments for each of the leading approaches and explain what the major challenges are for the future.Comment: 26 pages, 7 figures, 291 references. Early draft of Nature 464, 45-53 (4 March 2010). Published version is more up-to-date and has several corrections, but is half the length with far fewer reference

    Oral cancer treatment costs in Greece and the effect of advanced disease

    Get PDF
    BACKGROUND: The main purpose of the study was to quantify the direct costs of oral cancer treatment to the healthcare system of Greece. Another aim was to identify factors that affect costs and potential cost reduction items. More specifically, we examined the relationship between stage of disease, modality of treatment and total direct costs. METHODS: The medical records and clinic files of the Oral and Maxillofacial Clinic of the Athens General Hospital "Genimatas" were abstracted to investigate clinical treatment characteristics, including length of hospitalization, modes of treatment, stage of disease etc. Records of 95 patients with oral squamous cell carcinoma (OSSC), with at least six months of follow-up, were examined. The clinical data was then used to calculate actual direct costs, based on 2001 market values. RESULTS: The mean total direct costs for OSSC treatment estimated at euro 8,450 or approximately US$ 7,450. Costs depended on the stage of the disease, with significant increases in stages III and IV, as compared with stages I and II (p < 0.05). Multi-modality treatment applied mainly to patients in stages III and IV was the factor that affected the cost. Disease stage was also associated with the total duration of hospitalization (p < 0.05). CONCLUSIONS: The clinical management of advanced oral cancer is strongly associated with higher costs. Although the ideal would be to prevent cancer, the combination of high-risk screening, early diagnosis and early treatment seems the most efficient way to reduce costs, and most importantly, prolong life

    Creating a positive casual academic identity through change and loss

    Get PDF
    Neoliberalism has significantly impacted higher education institutes across the globe by increasing the number of casual and non-continuing academic positions. Insecure employments conditions have not only affected the well-being of contingent staff, but it has also weakened the democratic, intellectual and moral standing of academic institutions. This chapter provides one practitioner’s account of the challenges of casual work, but rather than dwelling on the negativities, it outlines the potential richness of an identity based on insecurity and uncertainty. This exploration draws on the literature of retired academics and identity theory to illustrate the potential generative spaces within an undefined and incoherent identity

    A genomic biomarker signature can predict skin sensitizers using a cell-based in vitro alternative to animal tests

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Allergic contact dermatitis is an inflammatory skin disease that affects a significant proportion of the population. This disease is caused by an adverse immune response towards chemical haptens, and leads to a substantial economic burden for society. Current test of sensitizing chemicals rely on animal experimentation. New legislations on the registration and use of chemicals within pharmaceutical and cosmetic industries have stimulated significant research efforts to develop alternative, human cell-based assays for the prediction of sensitization. The aim is to replace animal experiments with in vitro tests displaying a higher predictive power.</p> <p>Results</p> <p>We have developed a novel cell-based assay for the prediction of sensitizing chemicals. By analyzing the transcriptome of the human cell line MUTZ-3 after 24 h stimulation, using 20 different sensitizing chemicals, 20 non-sensitizing chemicals and vehicle controls, we have identified a biomarker signature of 200 genes with potent discriminatory ability. Using a Support Vector Machine for supervised classification, the prediction performance of the assay revealed an area under the ROC curve of 0.98. In addition, categorizing the chemicals according to the LLNA assay, this gene signature could also predict sensitizing potency. The identified markers are involved in biological pathways with immunological relevant functions, which can shed light on the process of human sensitization.</p> <p>Conclusions</p> <p>A gene signature predicting sensitization, using a human cell line in vitro, has been identified. This simple and robust cell-based assay has the potential to completely replace or drastically reduce the utilization of test systems based on experimental animals. Being based on human biology, the assay is proposed to be more accurate for predicting sensitization in humans, than the traditional animal-based tests.</p

    Physics, Astrophysics and Cosmology with Gravitational Waves

    Get PDF
    Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers), and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.Comment: 137 pages, 16 figures, Published version <http://www.livingreviews.org/lrr-2009-2

    Understanding adolescent and young adult use of family physician services: a cross-sectional analysis of the Canadian Community Health Survey

    Get PDF
    BACKGROUND: Primary health care is known to have positive effects on population health and may reduce at-risk behavior and health problems in adolescence. Yet little is known about the factors that are associated with adolescent and young adult utilization of family physician services. It is critical to determine the factors associated with utilization to inform effective primary health care policy. We address this gap in the primary health care literature by examining three issues concerning adolescent and young adult family physician use: inequity; the unique developmental stage of adolescence; and the distinction between utilization (users versus non-users) and intensity (high users versus low users). METHODS: We conducted nested logistic regressions for two outcomes: utilization and intensity of family physician services for early adolescence, middle adolescence, and young adulthood using the 2005 Canadian Community Health Survey. RESULTS: Chronic conditions were associated with utilization in early and middle adolescence and intensity in all age groups. Respondents from Quebec had lower odds of utilization. Those without a regular medical doctor had much lower odds of being users. The factors associated with use in early and middle adolescence were in keeping with parental involvement while the factors in young adulthood show the emerging independence of this group. CONCLUSIONS: We highlight key messages not known previously for adolescent and young adult use of family physician services. There is inequity concerning regional variation and for those who do not have a regular medical doctor. There is variation in factors associated with family physician services across the three age groups of adolescence. Health care and health care policies aimed at younger adolescents must consider that parents are still the primary decision-maker while older adolescents are more autonomous. There is variation in the factors associated with the two outcomes of utilization and intensity of services. Factors associated with utilization must be understood when considering the equitability of access to primary health care while factors associated with intensity must be understood when considering appropriate use of resources. The understanding gained from this study can inform health care policy that is responsive to the critical developmental stage of adolescence and young adulthood
    corecore