Pensamiento matemático en la cultura OTOMÍ

La investigación se centra en la forma en que se manifiesta el pensamiento matemático en uno de los grupos más antiguos de México establecido en el centro del país, específicamente en el Valle del Mezquital en el estado de Hidalgo, las matemáticas en el valle se observan en las actividades cotidianas como: bordados sobre telas diversas, tejido de canastos, ayates, siembras, construcción de viviendas, técnicas de cultivo y pastoreo, todo esto tiene un parámetro de medición así como de número y otras situaciones que vienen a conformar un mundo de conocimiento matemático relacionado con la cultura Otomí. Se toma como referencia a Bishop (1988), con las actividades: diseñar, localizar, medir, contar, jugar, explicar.. El diseño viene a ser una de las actividades centrales del grupo por la gran creatividad que se tiene y que muchas veces sirve como parte de un ingreso económico de las familias, en ella se tiene mucho de un conocimiento matemático, se tiene una forma de medir, distribuir, contar, ubicar, y socializar el conocimiento

The impact of diabetes on employment in Mexico

This study explores the impact of diabetes on employment in Mexico using data from the Mexican Family Life Survey (MxFLS) (2005), taking into account the possible endogeneity of diabetes via an instrumental variable estimation strategy. We find that diabetes significantly decreases employment probabilities for men by about 10 percentage points (

Versatile roles of protein flavinylation in bacterial extracyotosolic electron transfer

Bacteria perform diverse redox chemistries in the periplasm, cell wall, and extracellular space. Electron transfer for these extracytosolic activities is frequently mediated by proteins with covalently bound flavins, which are attached through post-translational flavinylation by the enzyme ApbE. Despite the significance of protein flavinylation to bacterial physiology, the basis and function of this modification remain unresolved. Here we apply genomic context analyses, computational structural biology, and biochemical studies to address the role of ApbE flavinylation throughout bacterial life. We identify ApbE flavinylation sites within structurally diverse protein domains and show that multi-flavinylated proteins, which may mediate longer distance electron transfer via multiple flavinylation sites, exhibit substantial structural heterogeneity. We identify two novel classes of flavinylation substrates that are related to characterized proteins with non-covalently bound flavins, providing evidence that protein flavinylation can evolve from a non-covalent flavoprotein precursor. We further find a group of structurally related flavinylation-associated cytochromes, including those with the domain of unknown function DUF4405, that presumably mediate electron transfer in the cytoplasmic membrane. DUF4405 homologs are widespread in bacteria and related to ferrosome iron storage organelle proteins that may facilitate iron redox cycling within ferrosomes. These studies reveal a complex basis for flavinylated electron transfer and highlight the discovery power of coupling comparative genomic analyses with high-quality structural models

Metodologia na pesquisa epidemiológica de doenças respiratórias e poluição ambiental

There are complex and diverse methodological problems involved in the clinical and epidemiological study of respiratory diseases and their etiological factors. The association of urban growth, industrialization and environmental deterioration with respiratory diseases makes it necessary to pay more attention to this research area with a multidisciplinary approach. Appropriate study designs and statistical techniques to analyze and improve our understanding of the pathological events and their causes must be implemented to reduce the growing morbidity and mortality through better preventive actions and health programs. The objective of the article is to review the most common methodological problems in this research area and to present the most available statistical tools used.Existem problemas metodológicos diversos e complexos envolvidos no estudo clínico e epidemiológico de doenças respiratórias e seus fatores etiológicos. A associação do crescimento urbano, da industrialização e da deterioração ambiental com as doenças respiratórias torna necessário focalizar a atenção a esse campo de estudo com uma abordagem multidisciplinar. Devem ser implementados modelos de estudo e técnicas estatísticas adequadas para analisar e melhorar o entendimento sobre os eventos patológicos e suas causas e para reduzir a crescente morbimortalidade fazendo uso de medidas preventivas e melhores programas de saúde. O objetivo do artigo é revisar os problemas metodológicos mais comuns nessa área de pesquisa e apresentar os métodos estatísticos usados de maior acesso

Códice Florentino y Pensamiento Matemático. Cultura Otomí en el Valle del Mezquital

El presente trabajo estudia las manifestaciones matemáticas de la cultura Otomí, específicamente en el Valle del Mezquital en Hidalgo con la finalidad de identificar y precisar la forma en que la inteligencia humana expresa por medio de elementos simbólicos nociones básicas de tiempo, espacio, número, en las actividades que se desarrollan en el contexto, bordados, tejidos, siembras, en el mercado, etc. Las acciones realizadas durante la elaboración de objetos transformados para cubrir necesidades fundamentales de la vida cotidiana, ponen de manifiesto el pensar matemático. Los errores en los resultados suponen consecuencias prácticas y no teóricas. Las observaciones y entrevistas realizadas permiten identificar seis actividades pertinentes (Bishop 1988), con la finalidad de encontrar situaciones que ejemplifiquen lo que propone Plan y Programas de la Educación Nacional Básica. Se realiza un acercamiento del conocimiento local matemático al Nacional con el diseño de actividades siguiendo los objetivos, alcances, contenidos, que el libro de matemáticas de primer grado de Educación Primaria tiene. Esta propuesta, en la perspectiva de los Modelos Teóricos Locales (Filloy, 1996), espera proporcionar al profesor la oportunidad de comunicar, sugerir y adaptar ese conocimiento local, de acuerdo a su experiencia y a sus necesidades que el tiene en el contexto en donde trabaja - es decir, sus propias necesidades - en sus propias maneras, desde sus propias perspectivas, utilizando sus propios medios y términos, porque finalmente son ellos los que viven la complejidad de la cultura Otomí en contraste con la educación Nacional

Plain water consumption is associated with lower intake of caloric beverage: cross-sectional study in Mexican adults with low socioeconomic status

Fifteen level single phase multilevel inverter is constructed using power circuit consist of 7 MOSFETs, seven independents DC sources, seven diodes, and an H-Bridge circuit. Switching method used in this MLI is sinusoidal pulse width modulation (SPWM) multicarrier where the reference wave in the form of a sinusoidal wave.  Multicarrier SPWM circuit is designed using electronic components such as Op-Amp that used as a comparator and some logic gates such as AND, OR and NOT gate to trigger S1, S2, S3, S4, S5, S6, S7, and H-Bridge circuit. Carrier waves used in this MLI modified from the triangle wave that having a frequency into carrier waves without frequency (DC sources) where THD that generated into 5.502%. While methods that use frequency such as Phase Disposition PWM (PD PWM), Phase Shift PWM (PS-PWM), and Carrier Overlapping PWM (CO PWM) that produces THD greater than the proposed method, this system was simulated using PSIM software. Abstract — Fifteen level single phase multilevel inverter is constructed using power circuit consist of 7 MOSFETs as switch, 7 indevendent DC sources, 7 diodes, and a H-Bridge. Trigering technic using sinusoidal pulse width modulation (SPWM) with 14 carrier wave, which pure sinusoidal wave as reference, SPWM circuit is disained using Op-Amp as comparator and some logic gates such as AND, OR and NOT gate in order to triggering S1, S2, S3, S4, S5, S6 and S7. By modificated carrier wave from triangular into DC source wave, this MLI produces THD output wave equal to 5.5019684%, while using methodes Phase Disposition PWM (PD PWM), Phase Shift PWM (PS PWM), and Carrier Overlapping PWM (CO PWM) produces THD more than proposed method, this system simulated using PSIM program. Keywords: Multilevel Inverter, SPWM, THD, PSI

Intravitreal Bevacizumab for Choroidal Metastasis of Lung Carcinoma; a Case Report

Purpose: To report an alternative treatment for metastatic tumors within the eye. Case Report: Five intravitreal injections of bevacizumab (2.5 mg each) were performed in one eye of a 50-year-old woman with choroidal metastasis of lung carcinoma. Tumor size was reduced, pain disappeared, vision improved, and there were no secondary reactions. Vision improved from 20/40 to 20/20 and metamorphopsia decreased. Ten months after initiating treatment, an ultrasonographic study revealed no residual tumor, the choroid was normal in thickness and fluorescein angiography revealed a scar but no mass lesion. Conclusion: Intravitreal bevacizumab displayed beneficial effects in reducing tumor size and improving symptoms in this case of choroidal metastasis of lung carcinoma. The antineoplasic properties of this agent make it a viable alternative for treatment of metastatic choroidal tumors

Characterization of Breakfast Cereals Available in the Mexican Market: Sodium and Sugar Content.

Preschool Mexican children consume 7% of their total energy intake from processed breakfast cereals. This study characterized the nutritional quality and labelling (claims and Guideline Daily Amount (GDA)) of the packaged breakfast cereals available in the Mexican market. Photographs of all breakfast cereals available in the 9 main food retail chains in the country were taken. The nutrition quality of cereals was assessed using the United Kingdom Nutrient Profiling Model (UKNPM). Claims were classified using the International Network for Food and Obesity/non-communicable Diseases Research, Monitoring and Action Support (INFORMAS) taxonomy and the GDA was defined according to the Mexican regulation, NOM-051. Overall, a total of 371 different breakfast cereals were analysed. The nutritional profile showed that 68.7% were classified as "less healthy". GDAs and claims were displayed more frequently on the "less healthy" cereals. Breakfast cereals within the "less healthy" category had significantly higher content of energy, sugar and sodium (p < 0.001). Most of the claims were displayed in the "less healthy" cereals (n = 313). This study has shown that there is a lack of consistency between the labelling on the front of the pack and the nutritional quality of breakfast cereals

Linking socioeconomic inequalities and type 2 diabetes through obesity and lifestyle factors among Mexican adults: a structural equations modeling approach

Objective. To assess the association between type 2 dia­betes (DM2) and socioeconomic inequalities, mediated by the contribution of body mass index (BMI), physical activity (PA), and diet (diet-DII). Materials and methods. We conducted a cross-sectional analysis using data of adults participating in the Diabetes Mellitus Survey of Mexico City. Socioeconomic and demographic characteristics as well as height and weight, dietary intake, leisure time activity and the presence of DM2 were measured. We fitted a structural equation model (SEM) with DM2 as the main outcome, and BMI, diet-DII and PA served as mediator variables between socioeconomic inequalities index (SII) and DM2. Results. The prevalence of DM2 was 13.6%. From the fitted SEM, each standard deviation increases in the SII was associated with increased scores of DM2 (β=0.174, P<0.001). Conclusion. The results in the present study show how high scores in the index of SII may influence the presence of DM2