The Contribution of Heredity to Clinical Obesity

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

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

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

Coherent frequentism

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

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

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

Simplified antiviral prophylaxis with or and without artificial feeding to reduce mother-to-child transmission of HIV in low and middle income countries: modelling positive and negative impact on child survival.

BACKGROUND: Antiviral prophylaxis is recommended for HIV positive mothers to prevent mother-to-child transmission of HIV. To date UNAIDS and WHO policy has been based on a study in Thailand which showed a reduction in transmission by half with short course AZT (Zidovudine) treatment together with artificial feeding. We modelled the possible positive and negative effects on child deaths in low and middle resource developing country settings of two interventions to reduce mother to child transmission (MTCT) of HIV: antenatal testing, short-course antivirals (zidovudine or nevirapine), firstly with and then without artificial feeding. MATERIAL AND METHODS: Estimates are made of child lives likely to be saved by the programme by age ten years, balanced against increases in deaths due to more uninfected mothers choosing to use artificial feeds where these are part of the intervention. Mid-point values for variables affecting the balance of mortality gains and losses are taken from recent published data for low and middle income developing countries and a sensitivity analysis is undertaken. RESULTS: In low income settings the use of antivirals alone would result in an estimated gain in child survival of around 0.36%, representing 360 deaths avoided from a birth cohort of 100,000 by age 10 years. Adding artificial feeding could reduce the gain to 0.03% (30 deaths avoided). In middle income settings the gain from antivirals alone would be 0.26% but as 'spill-over' of artificial feeding to uninfected women was more likely it could result in a net increase of child deaths of up to 1.08% (1,080 additional deaths). A sensitivity analysis emphasised this potential for regimens using artificial feeding if progamme participation was low, and under most circumstances in middle income settings. CONCLUSIONS: HIV testing and use of antivirals by infected mothers, if well implemented, will be effective at a population level in reducing MTCT. However the addition of artificial feeding is potentially be a high risk strategy, especially in middle income countries.sch_iih7pub2814pub

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

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

Inferential models: A framework for prior-free posterior probabilistic inference

Posterior probabilistic statistical inference without priors is an important but so far elusive goal. Fisher's fiducial inference, Dempster-Shafer theory of belief functions, and Bayesian inference with default priors are attempts to achieve this goal but, to date, none has given a completely satisfactory picture. This paper presents a new framework for probabilistic inference, based on inferential models (IMs), which not only provides data-dependent probabilistic measures of uncertainty about the unknown parameter, but does so with an automatic long-run frequency calibration property. The key to this new approach is the identification of an unobservable auxiliary variable associated with observable data and unknown parameter, and the prediction of this auxiliary variable with a random set before conditioning on data. Here we present a three-step IM construction, and prove a frequency-calibration property of the IM's belief function under mild conditions. A corresponding optimality theory is developed, which helps to resolve the non-uniqueness issue. Several examples are presented to illustrate this new approach.Comment: 29 pages with 3 figures. Main text is the same as the published version. Appendix B is an addition, not in the published version, that contains some corrections and extensions of two of the main theorem

Improving the quality of care of children in community clinics: an intervention and evaluation in Bangladesh.

Community health care providers (CHCPs) in 40 rural community clinics of Comilla district, Bangladesh, were trained using a newly developed case-management job aid based on the World Health Organization Integrated Management of Childhood Illness and a communication guide.To assess 1) the change in knowledge of the CHCPs after training; 2) the absolute quality of care provided by the CHCPs (determined as the proportion of children aged <5 years [under-fives] correctly diagnosed, treated and referred); and 3) the consultation behaviour of the CHCPs.Change in knowledge was assessed by tests pre-and post-training. The quality of care was determined by reassessments at the clinic exit by a medical officer, without a baseline comparison. Consultation behaviour was assessed through direct observation. The study was performed during 2014-2015.The mean standard knowledge score of the CH-CPs increased from 19 to 25 (P < 0.001). Of 1490 under-fives examined, 91% were correctly diagnosed, 86% were correctly treated and 99.5% received a correct referral decision. The CHCPs performed well on most of the measures of good communication, although one third did not explain the diagnosis and treatment to patients.The training was effective in changing knowledge. The CHCPs applied the knowledge gained and provided good quality care. Following these results, the Bangladesh Ministry of Health and Family Welfare has scaled up the training nationwide. The lessons learnt should be useful for other countries

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

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