A Simple Monte Carlo Framework to Assess Suicide Risk in Adolescents: A Study at a High School in Colombia.

It is very common to perform statistical tests to obtain insights about populations based on samples. For instance, in the context of psychology, when a set of instruments are applied to individuals, psychologists typically look for an explanation of particular psychological constructs (variables), such as personality, intelligence, or emotional functioning. It is common to cross statistical information from the results of different psychological tests to measure certain variables or to confirm prior beliefs. Here, we estimate the Joint Probability Density Function of suicide-related vulnerability and protective factors to assess suicide risk in adolescents. A Markov Chain Monte Carlo Method is employed to move away from the typical Gaussian assumption on data. This allows us to estimate probabilities of the development of suicidal ideation based on samples (which form a Markov chain). We employ our proposed statistical method at a high school in Colombia. The results reveal that adolescents can develop suicidal ideation as a consequence of the following factors, together with their corresponding probabilities: poor school performance 52%, low academic expectations 27%, school integration problems 68%, risky eating behaviors (binge-purge) 42%, risky eating behaviors (compensatory measurements) 21%, risky eating habits (restriction) 22%, and low family functionality 16%.

On the mathematical modelling and data assimilation for air pollution assessment in the Tropical Andes.

Air pollution assessment in the Tropical Andes requires a multidisciplinary approach. This can be supported from the understanding of the underlying biological dynamics and atmospheric behavior, to the mathematical approach for the proper use of all available information. This review paper touches on several aspects in which mathematical models can help to solve challenging problems regarding air pollution in reviewing the state-of-the-art at the global level and assessing the corresponding state of development as applied to the Tropical Andes. We address the complexities and challenges that modelling atmospheric dynamics in a mega-diverse region with abrupt topography entails. Understanding the relevance of monitoring and facing the problems of data scarcity, we call attention to the usefulness of data assimilation for uncertainty reduction, and how these techniques could help tackle the scarcity of regional monitoring networks to accelerate the implementation and development of modelling systems for air quality in the Tropical Andes. Finally, we suggest a cyberphysical framework for decision-making processes based on the data assimilation of chemical transport models, the forecast of scenarios, and their use in regulation and policy making.

A Maximum Likelihood Ensemble Filter Via A Modified Cholesky Decomposition For Non-Gaussian Data Assimilation.

This paper proposes an efficient and practical implementation of the Maximum Likelihood Ensemble Filter via a Modified Cholesky decomposition (MLEF-MC). The method works as follows: via an ensemble of model realizations, a well-conditioned and full-rank square-root approximation of the background error covariance matrix is obtained. This square-root approximation serves as a control space onto which analysis increments can be computed. These are calculated via Line-Search (LS) optimization. We theoretically prove the convergence of the MLEF-MC. Experimental simulations were performed using an Atmospheric General Circulation Model (AT-GCM) and a highly nonlinear observation operator. The results reveal that the proposed method can obtain posterior error estimates within reasonable accuracies in terms of ℓ - 2 error norms. Furthermore, our analysis estimates are similar to those of the MLEF with large ensemble sizes and full observational networks.

Diabetes gestacional, hipotiroidismo y concentración urinaria de yodo en embarazadas. Yodurias en escolares en Paraguay: Exceso de yodo en la sal y riesgo de hiper e hipotiroidismo / Gestational diabetes, hypothyroidism and iodine urinary concentration in pregnant women. Urinary iodine in schoolage children in Paraguay: Iodine excess in salt and hyper and hypothyroidism risk

The main inclicator of iodine nutritional status of salt for human con-sumption is the urinary concentration of iodine, which is useful in monitoring universal levels in salt. Paraguay has suffered deficiency in salt with highprevalence of goiter in thepopulation reaching48.6%. In 2000, results of the ThyroidMobileproject in Latin America showed a goiter prevalence of 17% but 79.6% of the consumed iodized salt was adequate in paraguayan households (more than 15 ppm of iodine). The average values of iodine urinary concentration in 4487 scholars was 437 µg/L, 30% of the average value was between the ideal of 100 to 199 µg/L and 46.1% were above 300 mg/L, with risk of excess iodine. Urinary concentration of iodine during pregnancy was measure for the first time in Paraguay in 200 women; the average was 484 µg/L but diabetes and hypothyroidism during pregnancy was observe in 50% of them. Objective: Determine iodine concentration in urine of the school population in 17 departments of the country and measure the levels of iodine in urine in 200 pregnant women from 15-37 years of age and their levels of glycaemia, and thyroid TSH. Methods: During the years, 2006 and 2007 were evaluated 4487 school randomized, in a probabilistic sample, 3198 in rural areas and 1,289 in urban areas; casual urine samples was collected to determine iodine content. The urinary concentration of iodine in two hundredpregnant women, concentration of iodine in salt, and levels of glycaemia and TSH were also included in the present study All candidates agreed with the informed consent under the ethics rules. Results: These data showed by comparing the levels of iodine in urine concentration in more than adequate and excessive level but this last was markedly elevated (93.8%). The median level greater than 300 µg/L was observed in 100% of the 4,487 urine samples, while the median urinary iodine levels of300-500 µg/L was 91.3% and above 500 was 9.7%. These levels showed the risk of developing thyroid autoimmune diseases. In 200 pregnancy women the average of urine concentration of iodine was 498 pcg/L, subclinical and clinical hypothyroidism and gestational diabetes was 50% of both. Conclu-sion: To obtain normal median urinary iodine levels is necessary to decrease the amount of iodine in salt. The main recommendation is to insist on adequate monitoring of iodized salt consumption. Also continue surveillance and monitoring in sentinel sites reporting the importance of adequate iodine intake of the population especially in pregnant women that also need to be warm about the diabetes during pregnancy but also a regimen is necessary to keep them within the normal levels of glycemia. The subclinical hypothyroidism has been also studied in the same patients.

El principal indicador del impacto de la yodación de la sal de consumo humano es la concentración urinaria de yodo la cual es útil en el monitoreo de la sal. En la encuesta del año 1988 realizada en el Paraguay, se alcanzó una prevalencia de bocio de 48,6% en la población escolar con un déficit de yodo en la sal, pero el año 2000 en el estudio del proyecto de Tiroides Móvil, se redujo por el método ecográfico a 17%. Ese mismo año la mediana de los niveles urinarios en niños escolares de 6-12 años fue 258 µg/L, considerando que 30% se encontraba entre el valor ideal de 100 a 199 µg/L y 46,1% sobre 300 µg/L, implicando un riesgo de exceso de yodo en dicha población con las posibles consecuencias de aparición tanto de hipo como de hipertiroidismo. El 93% presentó exceso de yodo en la sal y la mediana urinaria fue 437 ug/ mL. Un grupo de embarazadas han sido estudiadas en el Hospital San Pablo por primera vez en el Paraguay para la determinación de la yoduria, yodo en sal, diabetes gestacional, hipotiroidismo en el embarazo y sus valores antropométricos resultando un hipotiroidismo subclínico del 50% y diabetes gestacional del 50%. Objetivo: Determinar las yodurias en la población escolar de 6-12 años pre púber de ambos sexos en 17 departamentos del país y en una submuestra en embarazadas y también niveles de glicemia en el embarazo en un hospital de Asunción. Sujetos y Métodos: En el periodo del 2006-2007 fueron evaluados 4.487 escolares randomizados, en una muestra probabilística, 3.198 en el área rural y 1.289 en el área urbana con muestras en orina casual. El año 2015, doscientas embarazadas fueron estudiadas con muestras de glicemia en ayunas y 2 horas post prandial, dosaje de TSH, yodo en sal de 100 gramos de la sal de consumo en sus hogares y de orina para ver la concentración de yodo en sal y urinaria de yodo. Todos los candidatos fueron estudiados bajo consentimiento autorizado y de acuerdo a normas éticas. Resultados: Al comparar los niveles de yodo en orina en el nivel más que adecuado y el excesivo de la yoduria se vió que éste último nivel estaba marcadamente elevado (93.8%), que la mediana de los niveles mayores a 300 ug/L era del 100% del total de las 4.487 muestras de orina, mientras que la mediana de los niveles de yoduria entre 300-500 µg/L fue de 91,3% y por encima de 500 fue 9.7% lo cual implicó el riesgo de desarrollar enfermedades tiroideas autoinmunes. Las embarazadas presentaron una mediana urinaria de yodo 484 µg/L, diabetes gestacional e hipotiroidismo subclínico en 50%. Conclusión: Para normalizar los niveles de yoduria, es necesario disminuir la cantidad de yodo en la sal. La recomendación es insistir en el monitoreo de la adecuada yodación de las sales de consumo familiar y continuar con la vigilancia y el monitoreo constante en sitios centinelas divulgando la importancia de la adecuada ingesta de yodo a la población. Un régimen dietético a las embarazadas es necesario implementar en el primer trimestre del embarazo.

Alteraciones de los valores normales de yoduria en los niños de la escuela Juan de Salazar de la ciudad de Limpio / Alterations of normal values of ioduria in children of school Juan de Salazar of Limpio city

Introducción: Los valores alterados de yodo, ya sean inferiores o superiores al rango normal producen alteraciones en la función tiroidea. Con el presente trabajo, se determinó la yoduria en niños de 5 a 13 años de la escuela Juan de Salazar de la Ciudad de Limpio en el primer semestre del 2010. Diseño: Es un estudio observacional, descriptivo, de corte transverso, retrospectivo. Muestreo probabilístico. Resultados: La muestra estudiada estaba constituida por 83 niños, de los cuales 30 arrojaron valores de yoduria alterados. De los alterados, el 46.66% correspondió al sexo femenino y el restante, 53.33%, correspondió al sexo masculino. La edad promedio fue de 8.60 con extremos de 5 y 13 años. Al rango etario de 8 a10 años le corresponde el 53.33% del total de niños con valores alterados. Entre los niños con valores de yoduria superiores a los normales, 9 fueron del sexo masculino (47.36%), y 10 fueron del sexo femenino (52.63%). Entre los niños con valores de yoduria inferiores a los normales, 7 fueron del sexo masculino (63.63%), y 4 fueron del sexo femenino (36.36%).

Venas superficiales del antebrazo: estudio anatomoquirúrgico orientado a los angioaccesos para hemodiálisis crónica / Superficial veins of the forearm: anatomosurgical study as regards to accesses for chronic hemodialysis

Estudio anatómico prospectivo de las venas superficiales de los antebrazos de 70 cadáveres humanos. El análisis estadístico de los resultados busca establecer las características morfológicas de estas venas que no constan en las descripciones anatómicas clásicas y que condicionan su utilidad en la realización de angioaccesos para hemodiálisis crónica(AU)