1,241 research outputs found

    The Contribution of Heredity to Clinical Obesity

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    In order to discuss the contribution of heredity to clinical obesity, we first need to define our terms of reference to give us the common ground that is needed to explore the relationship between heredity, the environment, and clinical obesity. This will also serve to introduce these subjects for later chapters of this volume covering other aspects of the relative contributions of heredity and environment to the final clinical outcome of obesity. The importance of understanding the mechanisms underlying obesity cannot be overstated. Global rates of obesity are rising fast in most countries and the economic implications for maintaining the health care systems of those countries under the increasing burden of comorbidities and ill health are enormous [1]. Defining Heredity Heredity can simply be defined as the transmission of characteristic traits from parent to offspring. In the mid-nineteenth century, Mendel took this idea and by painstaking experimentation was able to formalize it as his two laws of heredity: the law of segregation and the law of independent assortment. The study of the science of heredity is genetics. In the twenty-first century, we now know the molecular basis of the principles of heredity and though our understanding of human genetics is by no means complete, the information that we have on DNA, the human genome sequence, epigenetics, and the environment all inform our understanding of heredity. We should be clear from the outset that using the term heredity does not imply that there is a purely genetic mechanism underlying the transmission of a trait. For many common traits, and for common obesity in particular, the influence of the environment is clearly strong

    Infection control in a developing world.

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    The global HIV and tuberculosis (TB) epidemics have placed enormous burdens upon already overstretched healthcare workers and poorly resourced healthcare facilities in sub-Saharan Africa. The rapid emergence of multi-drug resistant TB, and its association with hospital-based outbreaks, have highlighted the role that healthcare facilities inadvertently may play in maintaining TB transmission, and the vital importance of attaining good TB infection control. James Elston, a specialist physician in infectious diseases and general internal medicine, who recently returned from a second stint in Swaziland, says many of the region's healthcare facilities are outdated, poorly ventilated, and were not designed for their current purpose. Here he describes how U.K.-based architects and healthcare engineers responded to an urgent call for assistance and, via close collaboration, and using novel design software, empowered healthcare workers to dramatically and rapidly improve their TB inpatient facilities, and protect the health of patients and staff

    Study of Radiographic Linear Indications and Subsequent Microstructural Features in Gas Tungsten Arc Welds of Inconel 718

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    This study presents examples and considerations for differentiating linear radiographic indications produced by gas tungsten arc welds in a 0.05-in-thick sheet of Inconel 718. A series of welds with different structural features, including the enigma indications and other defect indications such as lack of fusion and penetration, were produced, radiographed, and examined metallographically. The enigma indications were produced by a large columnar grain running along the center of the weld nugget occurring when the weld speed was reduced sufficiently below nominal. Examples of respective indications, including the effect of changing the x-ray source location, are presented as an aid to differentiation. Enigma, nominal, and hot-weld specimens were tensile tested to demonstrate the harmlessness of the enigma indication. Statistical analysis showed that there is no difference between the strengths of these three weld conditions

    Low-Cycle Fatigue of Ultra-Fine-Grained Cryomilled 5083 Aluminum Alloy

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    The cyclic deformation behavior of cryomilled (CM) AA5083 alloys was compared to that of conventional AA5083-H131. The materials studied were a 100 pct CM alloy with a Gaussian grain size average of 315 nm and an alloy created by mixing 85 pct CM powder with 15 pct unmilled powder before consolidation to fabricate a plate with a bimodal grain size distribution with peak averages at 240 nm and 1.8 lm. Although the ultra-fine-grain (UFG) alloys exhibited considerably higher tensile strengths than those of the conventional material, the results from plastic-strain-controlled low-cycle fatigue tests demonstrate that all three materials exhibit identical fatigue lives across a range of plastic strain amplitudes. The CM materials exhibited softening during the first cycle, similar to other alloys produced by conventional powder metallurgy, followed by continual hardening to saturation before failure. The results reported in this study show that fatigue deformation in the CM material is accompanied by slight grain growth, pinning of dislocations at the grain boundaries, and grain rotation to produce macroscopic slip bands that localize strain, creating a single dominant fatigue crack. In contrast, the conventional alloy exhibits a cell structure and more diffuse fatigue damage accumulation

    Governed by history: Institutional analysis of a contested biofuel innovation system in Tanzania

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    Initially hailed as a miracle crop for biofuel production, Jatropha has recently attracted criticism for competing with food production, causing adverse biodiversity impacts, and jeopardizing land access by rural populations in tropical countries. This paper analyzes the contested development of Jatropha biofuel sector in Tanzania by anchoring two new concepts of ‘organizational models’ and ‘institutional arrangements’ to the sectoral systems of innovation perspective. The notion of ‘organizational models’ brings into relief the heterogeneity of actors in an innovation system and the ways in which the actors form networks, within and across national borders, to organize innovative activities. The concept of ‘institutional arrangements’ refers to the ensemble of formal and informal institutions assembled during Tanzania’s colonial and post-colonial eras, which directly govern innovative activities in specific organizational models. Based on a location-specific and historically-grounded institutional analysis within the innovation system framework, implications are drawn for the future development of Tanzania’s Jatropha sector including its links with European markets and for the regulation of ‘next-generation’ biofuels

    Patterns of antihypertensive prescribing, discontinuation and switching among a Hong Kong Chinese population from over one million prescriptions

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    Hypertension is an alarming public health problem among Chinese. The present study evaluated the prescribing patterns, discontinuation and switching profiles of antihypertensive agents and their associated factors in one Hong Kong Chinese population. Data were retrieved from computerized records for patients prescribed anti-hypertensive agents in government primary care clinics of Hong Kong from January, 2004 to June, 2007. A total of 1,069,836 antihypertensive drug visits, representing 67,028 patients, were analyzed. The most commonly prescribed drugs were Calcium Channel Blockers (CCBs) (49%), b-Blockers (BBs) (46%) and Angiotensin-Converting Enzyme Inhibitors (ACEIs) (19%). Thiazide diuretic prescribing was low (13%) and on the decline (14% in 2004 to 12% in 2007). Prescribing of ACEIs was rising (16% in 2004 to 23% in 2007). Patients’ age, gender, and socio-economic status were independent predictors of class of anti-hypertensive prescribed but explained less than 3.5% of the variation observed. Drug discontinuation was highest for BBs (21%) and lowest for CCBs (12%). The high rates of discontinuation in BBs remained apparent after controlling for confounding variables. Switching was less common than discontinuation and was most likely with thiazide diuretics. To summarize, prescribing of CCBs and BBs were high and that of thiazide diuretics particularly low in this Chinese population when compared with international trends. CCBs may be a particularly favorable antihypertensive treatment in Chinese, given the high discontinuation rates of BBs and international guidelines advising against the use of BBs as first-line therapy. The low use of thiazide diuretics warrants further clinical and cost effectiveness studies among Chinese

    Process evaluation of integrated early child development care at private clinics in poor urban Pakistan: a mixed methods study

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    Background: In poor urban Pakistan, private GP clinics lack adequate services to promote early child development (ECD) care. A clinic-based contextualised ECD intervention was developed for quarterly tool-assisted counselling of mothers. Aim: To explore the experience and implementation of ECD intervention by the private care providers and clients, for further adaptation for scaling of quality ECD care, at primary level private healthcare facilities in Pakistan. Design & setting: A mixed methods approach using quantitative records review and qualitative interviews at poor urban clinics in Rawalpindi and Lahore, Pakistan. Method: Quantitative data from study-specific records were reviewed for 1242 mother–child pairs registered in the intervention. A total of 18 semi-structured interviews with clinic staff, mothers, and research staff were conducted at four clinics. The interviews were audiorecorded and transcribed verbatim. Results: District Health Office (DHO) support allowed transparent and effective selection and training of clinic providers. Public endorsement of ECD care at private clinics and the addition of community advocates promoted ECD care uptake. Clinic settings were found feasible for clinic assistants, and acceptable to mothers, for counselling sessions. Mothers found ECD counselling methods more engaging compared to the usual care provided. Conclusion: In poor urban settings where public health care is scarce, minimal programme investment on staff training and provision of minor equipment can engage private clinics effectively in delivering ECD care

    Coherent frequentism

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    By representing the range of fair betting odds according to a pair of confidence set estimators, dual probability measures on parameter space called frequentist posteriors secure the coherence of subjective inference without any prior distribution. The closure of the set of expected losses corresponding to the dual frequentist posteriors constrains decisions without arbitrarily forcing optimization under all circumstances. This decision theory reduces to those that maximize expected utility when the pair of frequentist posteriors is induced by an exact or approximate confidence set estimator or when an automatic reduction rule is applied to the pair. In such cases, the resulting frequentist posterior is coherent in the sense that, as a probability distribution of the parameter of interest, it satisfies the axioms of the decision-theoretic and logic-theoretic systems typically cited in support of the Bayesian posterior. Unlike the p-value, the confidence level of an interval hypothesis derived from such a measure is suitable as an estimator of the indicator of hypothesis truth since it converges in sample-space probability to 1 if the hypothesis is true or to 0 otherwise under general conditions.Comment: The confidence-measure theory of inference and decision is explicitly extended to vector parameters of interest. The derivation of upper and lower confidence levels from valid and nonconservative set estimators is formalize

    Delivering integrated child development care in Pakistan: protocol for a clustered randomised trial

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    Background: Early childhood developmental delay is associated with significant disadvantage in adult life. In Pakistan, high prevalence of developmental delay is associated with poverty, under-nutrition, and maternal depression. Aim: To assess the effectiveness of an early child development counselling intervention delivered at private GP clinics, in poor urban communities. Design & setting: A clustered randomised trial in Pakistan. Method: The intervention was developed following a period of formative research, and in consultation with local experts. A total of 2112 mother–child pairs will be recruited at 32 clinics, from within the locality (cluster); 16 clinics per arm. A primary care counselling intervention (promoting child development, nutrition, and maternal mental health) will be delivered at 6 weeks, 3, 6, and 9 months of the child’s age. Monitoring, assessment, and treatment will also be performed at quarterly visits in intervention clinics. Primary outcome is the developmental delay at 12 months (ASQ-3 scores). Secondary outcomes are stunting rate, and maternal depression (PHQ-9 score). In addition, a process evaluation and costing study will be conducted. Discussion: This trial will be the first to assess an early child development intervention, delivered in private GP clinics for poor urban communities in Pakistan. If found to be effective, this public–private model may offer a more sustainable, and feasible option for populations in poor urban settings, where private GP clinics are the most accessible provider of primary health care. There is scope for scale-up at provincial level, should the intervention be effective. Trial registration: The trial has been registered with the Current Controlled Trials ISRCTN48032200

    Does the process map influence the outcome of quality improvement work? A comparison of a sequential flow diagram and a hierarchical task analysis diagram

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    Background: Many quality and safety improvement methods in healthcare rely on a complete and accurate map of the process. Process mapping in healthcare is often achieved using a sequential flow diagram, but there is little guidance available in the literature about the most effective type of process map to use. Moreover there is evidence that the organisation of information in an external representation affects reasoning and decision making. This exploratory study examined whether the type of process map - sequential or hierarchical - affects healthcare practitioners' judgments.Methods: A sequential and a hierarchical process map of a community-based anti coagulation clinic were produced based on data obtained from interviews, talk-throughs, attendance at a training session and examination of protocols and policies. Clinic practitioners were asked to specify the parts of the process that they judged to contain quality and safety concerns. The process maps were then shown to them in counter-balanced order and they were asked to circle on the diagrams the parts of the process where they had the greatest quality and safety concerns. A structured interview was then conducted, in which they were asked about various aspects of the diagrams.Results: Quality and safety concerns cited by practitioners differed depending on whether they were or were not looking at a process map, and whether they were looking at a sequential diagram or a hierarchical diagram. More concerns were identified using the hierarchical diagram compared with the sequential diagram and more concerns were identified in relation to clinical work than administrative work. Participants' preference for the sequential or hierarchical diagram depended on the context in which they would be using it. The difficulties of determining the boundaries for the analysis and the granularity required were highlighted.Conclusions: The results indicated that the layout of a process map does influence perceptions of quality and safety problems in a process. In quality improvement work it is important to carefully consider the type of process map to be used and to consider using more than one map to ensure that different aspects of the process are captured
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