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Vitamin K is given to many babies born in the United Kingdom, but we still do not know if it has substantial hazards. Because the population exposed to vitamin K is very large even quite small hazards would involve many adverse events. It is therefore important to be able to put reasonably close bounds on the potential damage that vitamin K prophylaxis could cause. Past research has not allowed us to do this but a large randomised controlled clinical trial of vitamin K against no vitamin K, enrolling only infants at low risk of haemorrhagic disease, would do so. There is no question that vitamin K is a useful treatment in babies at highest risk of haemorrhagic disease: the question is whether the trend towards use of vitamin K in lower risk babies should be encouraged.  相似文献   

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《Current biology : CB》2019,29(22):R1163-R1165
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This paper addresses a fundamental question: Why are there sign-mediated interactions in biology? According to Polanyi, biological hierarchies are constituted through boundary conditions. I argue that signs, or more accurately the processes of signification, function as these boundary conditions. Moreover, based on general insights from the physics of computation, I argue that the organism cannot be computed directly from the DNA without the loss of critical information. In this context, signs as boundary conditions mediate the biological construction in a way that prevents the loss of information and destabilization of the DNA.  相似文献   

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Much of the spectacular progress in biomedical science over the last half-century is the direct consequence of the work of thousands of basic scientists whose primary goal was understanding of the fundamental working of living things. Despite this, many politicians, funders, and even scientists have come to believe that the pace of successful applications to medical diagnosis and therapy is limited by our willingness to focus directly on human health, rather than a continuing deficit of understanding. By this theory, curiosity-driven research, aimed at understanding, is no longer important or even useful. What is advocated instead is “translational” research aimed directly at treating disease. I believe this idea to be deeply mistaken. Recent history suggests instead that what we have learned in the last 50 years is only the beginning. The way forward is to invest more in basic science, not less.  相似文献   

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OBJECTIVE: To examine whether the sociodemographic and morbidity characteristics of populations influence their use of the following community heath services: district nursing, health visiting, chiropody, community maternity, community mental illness, and the professions allied to medicine. DESIGN: Observational study. SETTING: Nationally representative sample of provider trusts in England. MAIN OUTCOME MEASURES: Activity levels for each service calculated for enumeration districts within the catchment areas of the sample of trusts and standardised to allow for differences in age structure. Regression analysis to determine whether the standardised activity rates for each service could be predicted by a range of socio-demographic and morbidity proxies. RESULTS: Morbidity or deprivation, or both, seemed to influence the use of services in each of the care programmes examined. CONCLUSIONS: The allocation of funds for community health services should allow for differences in the health and socio-demographic characteristics of health authorities.  相似文献   

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This paper advances a unified approach to the modeling of sigmoid organismal growth. There are numerous studies on growth, and there have been several proposals and applications of candidate models. Still, a lack of interpretation of the parameter values persists and, consequently, differences in growth patterns have riddled this field. A candidate regression model as a tool should be able to assess and compare growth-curve shapes, systematically and precisely. The Richards models constitute a useful family of growth models that amongst a multitude of parameterizations, re-parameterizations and special cases, include familiar models such as the negative exponential, the logistic, the Bertalanffy and the Gompertz. We have reviewed and systemized this family of models. We demonstrate that two specific parameterizations (or re-parameterizations) of the Richards model are able to substitute, and thus to unify all other forms and models. This unified-Richards model (with its two forms) constitutes a powerful tool for an interpretation of important characteristics of observed growth patterns, namely, [I] maximum (relative) growth rate (i.e., slope at inflection), [II] age at maximum growth rate (i.e., time at inflection), [III] relative mass or length at maximum growth rate (i.e., relative value at an inflection), [IV] value at age zero (i.e., birth, hatching or germination), and [V] asymptotic value (i.e., adult weight or length). These five parameters can characterize uniquely any sigmoid-growth data. To date most studies only compare what is referred to as the “growth-rate constant” or simply “growth rate” (k). This parameter can be interpreted as neither relative nor actual growth rate, but only as a parameter that affects the slope at inflection. We fitted the unified-Richards and five other candidate models to six artificial data sets, generated from the same models, and made a comparison based on the corrected Akaike’s Information Criterion (AICc). The outcome may in part be the result of the random generation of data points. Still, in conclusion, the unified-Richards model performed consistently well for all data sets, despite the penalty imposed by the AICc.  相似文献   

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