Statistical Modeling of the Number of Deaths of Children in Bangladesh

Efforts to reduce the number of children’s death in developing countries through health care programs focus more to the prevention and control of diseases than to determining the underlying risk factors/predictors and addressing these through proper interventions. This study aims to identify socioeconomic and demographic predictors of the number of children’s death to women aged 12-49 from the Bangladesh Health and Demographic Survey (BDHS) administered in 2011. The number of children’s death in a family is a non-negative count response variable. The average number of children’s death is found to be 28 per 100 women with a variance of 44per 100 women. Thus Poisson regression model is not a proper choice to predict the mean response from the BDHS data due to the presence of over-dispersion. In order to address over-dispersion, we fit a Negative Binomial Regression (NBR), a Zero-Inflated Negative Binomial Regression (ZINBR) and a Hurdle Regression (HR) model. Among these models, ZINBR fits the data best. We identify respondent’s age, respondent’s age at 1st birth, gap between 1st birth and marriage, number of family members, region, religion, respondent’s education, husband’s education, incidence of twins, source of water, and wealth index as significant predictors for the number of children’s death in a family from the best fitted model. Identification of the risk factors of the number of children’s death is an important public health issue and should be carried out correctly for the much needed intervention

Preparation of Neutron-activated Xenon for Liquid Xenon Detector Calibration

We report the preparation of neutron-activated xenon for the calibration of liquid xenon (LXe) detectors. Gamma rays from the decay of xenon metastable states, produced by fast neutron activation, were detected and their activities measured in a LXe scintillation detector. Following a five-day activation of natural xenon gas with a Cf-252 (4 x 10^5 n/s) source, the activities of two gamma ray lines at 164 keV and 236 keV, from Xe-131m and Xe-129m metastable states, were measured at about 95 and 130 Bq/kg, respectively. We also observed three additional lines at 35 keV, 100 keV and 275 keV, which decay away within a few days. No long-lifetime activity was observed after the neutron activation.Comment: to be published in NIM A, corrected typos in Table 1 and Fig.6 of the previous versio

Corticosteroids for the treatment of Duchenne muscular dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy of childhood. Untreated, this incurable disease, which has an X-linked recessive inheritance, is characterised by muscle wasting and loss of walking ability, leading to complete wheelchair dependence by 13 years of age. Prolongation of walking is a major aim of treatment. Evidence from randomised controlled trials (RCTs) indicates that corticosteroids significantly improve muscle strength and function in boys with DMD in the short term (six months), and strength at two years (two-year data on function are very limited). Corticosteroids, now part of care recommendations for DMD, are largely in routine use, although questions remain over their ability to prolong walking, when to start treatment, longer-term balance of benefits versus harms, and choice of corticosteroid or regimen.We have extended the scope of this updated review to include comparisons of different corticosteroids and dosing regimens. OBJECTIVES: To assess the effects of corticosteroids on prolongation of walking ability, muscle strength, functional ability, and quality of life in DMD; to address the question of whether benefit is maintained over the longer term (more than two years); to assess adverse events; and to compare efficacy and adverse effects of different corticosteroid preparations and regimens. SEARCH METHODS: On 16 February 2016 we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, EMBASE, CINAHL Plus, and LILACS. We wrote to authors of published studies and other experts. We checked references in identified trials, handsearched journal abstracts, and searched trials registries. SELECTION CRITERIA: We considered RCTs or quasi-RCTs of corticosteroids (e.g. prednisone, prednisolone, and deflazacort) given for a minimum of three months to patients with a definite DMD diagnosis. We considered comparisons of different corticosteroids, regimens, and corticosteroids versus placebo. DATA COLLECTION AND ANALYSIS: The review authors followed standard Cochrane methodology. MAIN RESULTS: We identified 12 studies (667 participants) and two new ongoing studies for inclusion. Six RCTs were newly included at this update and important non-randomised cohort studies have also been published. Some important studies remain unpublished and not all published studies provide complete outcome data. PRIMARY OUTCOME MEASURE: one two-year deflazacort RCT (n = 28) used prolongation of ambulation as an outcome measure but data were not adequate for drawing conclusions. SECONDARY OUTCOME MEASURES: meta-analyses showed that corticosteroids (0.75 mg/kg/day prednisone or prednisolone) improved muscle strength and function versus placebo over six months (moderate quality evidence from up to four RCTs). Evidence from single trials showed 0.75 mg/kg/day superior to 0.3 mg/kg/day on most strength and function measures, with little evidence of further benefit at 1.5 mg/kg/day. Improvements were seen in time taken to rise from the floor (Gowers' time), timed walk, four-stair climbing time, ability to lift weights, leg function grade, and forced vital capacity. One new RCT (n = 66), reported better strength, function and quality of life with daily 0.75 mg/kg/day prednisone at 12 months. One RCT (n = 28) showed that deflazacort stabilised muscle strength versus placebo at two years, but timed function test results were too imprecise for conclusions to be drawn.One double-blind RCT (n = 64), largely at low risk of bias, compared daily prednisone (0.75 mg/kg/day) with weekend-only prednisone (5 mg/kg/weekend day), finding no overall difference in muscle strength and function over 12 months (moderate to low quality evidence). Two small RCTs (n = 52) compared daily prednisone 0.75 mg/kg/day with daily deflazacort 0.9 mg/kg/day, but study methods limited our ability to compare muscle strength or function. ADVERSE EFFECTS: excessive weight gain, behavioural abnormalities, cushingoid appearance, and excessive hair growth were all previously shown to be more common with corticosteroids than placebo; we assessed the quality of evidence (for behavioural changes and weight gain) as moderate. Hair growth and cushingoid features were more frequent at 0.75 mg/kg/day than 0.3 mg/kg/day prednisone. Comparing daily versus weekend-only prednisone, both groups gained weight with no clear difference in body mass index (BMI) or in behavioural changes (low quality evidence for both outcomes, one study); the weekend-only group had a greater linear increase in height. Very low quality evidence suggested less weight gain with deflazacort than with prednisone at 12 months, and no difference in behavioural abnormalities. Data are insufficient to assess the risk of fractures or cataracts for any comparison.Non-randomised studies support RCT evidence in showing improved functional benefit from corticosteroids. These studies suggest sustained benefit for up to 66 months. Adverse effects were common, although generally manageable. According to a large comparative longitudinal study of daily or intermittent (10 days on, 10 days off) corticosteroid for a mean period of four years, a daily regimen prolongs ambulation and improves functional scores over the age of seven, but with a greater frequency of side effects than an intermittent regimen. AUTHORS' CONCLUSIONS: Moderate quality evidence from RCTs indicates that corticosteroid therapy in DMD improves muscle strength and function in the short term (twelve months), and strength up to two years. On the basis of the evidence available for strength and function outcomes, our confidence in the effect estimate for the efficacy of a 0.75 mg/kg/day dose of prednisone or above is fairly secure. There is no evidence other than from non-randomised trials to establish the effect of corticosteroids on prolongation of walking. In the short term, adverse effects were significantly more common with corticosteroids than placebo, but not clinically severe. A weekend-only prednisone regimen is as effective as daily prednisone in the short term (12 months), according to low to moderate quality evidence from a single trial, with no clear difference in BMI (low quality evidence). Very low quality evidence indicates that deflazacort causes less weight gain than prednisone after a year's treatment. We cannot evaluate long-term benefits and hazards of corticosteroid treatment or intermittent regimens from published RCTs. Non-randomised studies support the conclusions of functional benefits, but also identify clinically significant adverse effects of long-term treatment, and a possible divergence of efficacy in daily and weekend-only regimens in the longer term. These benefits and adverse effects have implications for future research and clinical practice

The Decay of Disease Association with Declining Linkage Disequilibrium: A Fine Mapping Theorem

Several important and fundamental aspects of disease genetics models have yet to be described. One such property is the relationship of disease association statistics at a marker site closely linked to a disease causing site. A complete description of this two-locus system is of particular importance to experimental efforts to fine map association signals for complex diseases. Here, we present a simple relationship between disease association statistics and the decline of linkage disequilibrium from a causal site. Specifically, the ratio of Chi-square disease association statistics at a marker site and causal site is equivalent to the standard measure of pairwise linkage disequilibrium, r2. A complete derivation of this relationship from a general disease model is shown. Quite interestingly, this relationship holds across all modes of inheritance. Extensive Monte Carlo simulations using a disease genetics model applied to chromosomes subjected to a standard model of recombination are employed to better understand the variation around this fine mapping theorem due to sampling effects. We also use this relationship to provide a framework for estimating properties of a non-interrogated causal site using data at closely linked markers. Lastly, we apply this way of examining association data from high-density genotyping in a large, publicly-available data set investigating extreme BMI. We anticipate that understanding the patterns of disease association decay with declining linkage disequilibrium from a causal site will enable more powerful fine mapping methods and provide new avenues for identifying causal sites/genes from fine-mapping studies

Causal effects of PetroCaribe on sustainable development: a synthetic control analysis

We examine the causal effects of the energy subsidy programme PetroCaribe in the three dimensions of sustainable development: economic, social and environmental. We use the synthetic control method to construct a counterfactual and compare it to the outcomes of the beneficiary countries and thus estimate the magnitude and direction of the PetroCaribe effect. PetroCaribe had a positive effect on economic growth in most of the beneficiary countries; however, this economic boost was not followed by an improvement in social development. Environmentally, PetroCaribe did not negatively or positively impact the environmental quality of the member countries, in the sense that we do not find a significant effect on the trend of urn:x-wiley:14636786:media:manc12275:manc12275-math-0001 emissions per capita

Biomarcadores cardíacos: Presente y futuro

En la actualidad, las enfermedades cardiovasculares se consideran la pandemia más significativa del siglo XXI. Dentro de ellas, la enfermedad coronaria es la más prevalente y la que más morbi-mortalidad genera; en el caso particular de Colombia, es la principal causa de muerte en individuos mayores de 45 años. La característica silenciosa de esta enfermedad ha impulsado la investigación de moléculas que permitan su diagnóstico precoz y sirvan como predictores pronóstico tanto en la fase crónica como en la aguda.Fruto de estas investigaciones, en los últimos treinta años se ha producido un avance importante en el desarrollo de biomarcadores cardiacos. Entre ellos están los recién desarrollados ensayos de troponinas ultrasensibles para diagnóstico temprano, la medición de la albúmina modificada por isquemia que cuenta con alto valor predictivo negativo para la detección de isquemia miocárdica, el ligando de CD40 soluble para la clasificación e individualización del tratamiento, la utilidad de la proteína C reactiva como marcador de riesgo de enfermedad coronaria y las diversas técnicas de alto rendimiento como la proteómica, que permite la detección de múltiples biomarcadores potenciales. A pesar de ello, aún no se dispone de evidencia suficiente para sustituir los marcadores que recomiendan las asociaciones científicas por los nuevos marcadores que se han ido desarrollando, y continúa el debate sobre qué combinación utilizar para alcanzar mayor rendimiento diagnóstico, pronostico y terapéutico. A continuación se revisan los avances actuales en biomarcadores cardiacos y su potencial integración a la práctica clínica habitual.Cardiovascular diseases are currently considered the most significant pandemic of the XXI century. Among them, coronary disease is the most prevalent and the one that generates more morbidity and mortality. In Colombia, is the main cause of death in individuals over 45 years. The silent characteristics of this disease has promoted research of molecules that allow early diagnosis and serve as predictors of prognosis both in chronic and acute phases.As result of this research, there has been significant progress in the development of cardiac biomarkers in the last thirty years. Among them are the newly developed ultrasensitive troponin assays for an early diagnosis, measurement of ischemia modified albumin, which has high negative predictive value for the detection of myocardial ischemia, soluble CD40 ligand for classification and individualization of treatment, the usefulness of CRP as a risk marker for coronary heart disease and various high-throughput techniques such as proteomics, which allow the detection of multiple potential biomarkers. Despite this, there is still insufficient evidence for replacing the markers recommended by the scientific associations by new developed markers, and the debate about what combination to use in order to achieve higher performance diagnosis, prognosis and therapy, continues Here we review current advances in cardiac biomarkers and their potential integration into daily clinical practice

Electromyography and muscle biopsy in paediatric neuromuscular disorders – Evaluation of current practice and literature review

The conduct and interpretation of electromyography in children is considered difficult and therefore often avoided. We assessed the diagnostic accuracy of the paediatric electromyography protocol used in our tertiary reference centre and compared it to muscle biopsy results and clinical diagnosis. Electromyography was performed in unsedated children with suspected neuromuscular diseases between January 2010 and September 2017 and was analysed quantitatively. Muscle pathology was classified into seven groups based on existing histopathology reports. The clinical diagnosis, including myopathic, neurogenic and non-neuromuscular categories was used as the gold standard. 171 children between the age of 12 days to 17.4 years were included in the analysis. 41 children (24%) were under the age of 2 years at the time of electromyography. 98 (57%) children were diagnosed with a myopathic disorder, 18 (11%) with a neurogenic disease and 55 (32%) as not having a primary neuromuscular disorder. In detecting myopathic disease, electromyography performed as well as muscle biopsy (sensitivity 87.8% for electromyography vs. 84.5% for muscle biopsy; specificity 75.7% vs. 86.4%). This also applied to children under the age of 2 years (sensitivity 81.8% vs. 86.4%). Quantitative analysis of a limited electromyography protocol performed in unsedated children is a very valuable diagnostic tool

“Importancia de las rutas anapleróticas para el inicio del desarrollo de seres vivos con escaso material de reserva”

En este trabajo se propone demostrar la importancia de las rutas anapleróticas pococonsideradas y la necesidad de contar con niveles de CO2 superiores a los normales enla atmósfera, cuando se requieren elevadas actividades biosintéticas en organismosaeróbicos, por necesidades de proliferación y/o de producción de células vivas, o conpropiedades especiales, o metabolitos de interés industria

Modelado de la influencia de la microestructura en la microdureza de materiales con recubrimiento

Mediante simulación numérica se estudió la microdureza en un material metálico recubierto con óxido metálico. La simulación consiste de un contacto bidimensional axisimétrico entre un indentador esférico y un sistema sustrato-recubrimiento. Se consideró un sustrato formado por titanio recubierto con otro material más duro a diferentes cargas de indentación y espesores del recubrimiento, considerando dos casos: ambos materiales perfectamente adheridos o los dos materiales interactuando a través de una interfaz cohesiva. Se analizaron los efectos de las propiedades mecánicas de cada material sobre el comportamiento global del sistema, la relacion entre dureza y espesor del recubrimiento, la influencia de fallas locales en la interfaz y de la estructura de granos en sustrato y recubrimiento. Los resultados permitieron obtener correlaciones entre la dureza y las propiedades mecánicas y geométricas del sistema. Se destaca que cuando el recubrimiento es delgado es posible explicar la dispersión en resultados de microdureza en un material recubierto si se tienen en cuanta fallas de adhesión en la interfaz y la estructura de granos en el sustrato.Publicado en: Mecánica Computacional vol. XXXV no.36Facultad de Ingenierí