Early-Life Metabolic Traits and Physical Fitness in Tarahumara, Mennonite, and Mestizo Adolescents from Northern Mexico.

The WHO identifies high BMI, high blood pressure, and high fasting plasma glucose as chronic disease risk factors, whereas physical fitness is identified as a protective behavioral factor. This study responds to the rising interest in assessing metabolic factors and physical activity within young populations of Mestizo, Tarahumara, and Mennonite from Chihuahua Mexico, due to its strong relationship with disease development and low well-being. A cross-sectional study was conducted with 201 teenagers from rural towns in Northern Mexico, and relationships between physical fitness and cardio-metabolic risk related to anthropometric, glycolipid, and vascular function factors were assessed. ANOVA-tested differences among ethnic groups using physical fitness as a grouping variable and measures of cardio-metabolic risks were used as dependent variables. A stepwise regression analysis allowed us to identify the best predictors for physical fitness. Clinical risk factors were analyzed by ethnic group and sex. No differences were found among ethnic groups in physical fitness and cardio-metabolic health risks; sex differentiated higher health risks related to behavioral factors, since young women showed lower physical fitness across ethnicities. Clinically, the Mestizo sample showed higher numbers of individuals with one risk factor. Mennonites showed a high frequency of anthropometric and fitness health risks with low glycolipid and vascular risks. Tarahumara had fewer risk factors as compared with both Mestizo and Mennonite. Rural populations are harder to reach, both for health assessment and intervention; health professionals must work close to local community organizations to gain access.

Parameter Identification of Cardiovascular System Model Used for Left Ventricular Assist Device Algorithms.

Advancement of implanted left ventricular assist device (LVAD) technology includes modern sensing and control methods to enable online diagnostics and monitoring of patients using on-board sensors. These methods often rely on a cardiovascular system (CVS) model, the parameters of which must be identified for the specific patient. Some of these, such as the systemic vascular resistance (SVR), can be estimated online while others must be identified separately. This paper describes a three-staged approach for designing a parameter identification algorithm (PIA) for this problem. The approach is demonstrated using a two-element Windkessel model of the systemic circulation (SC) with a time-varying elastance for the left ventricle (LV). A parameter identifiability stage is followed by identification using an unscented Kalman filter (UKF), which uses measurements of LV pressure (Plv), aortic pressure (Pao), aortic flow (Qa), and known input measurement of LVAD flowrate (Qvad). Both simulation and experimental data from animal experiments were used to evaluate the presented methods. By bounding the initial guess for left ventricular volume, the identified CVS model is able to reproduce signals of Plv, Pao, and Qa within a normalized root mean squared error (nRMSE) of 5.1%, 19%, and 11%, respectively, during simulations. Experimentally, the identified model is able to estimate SVR with an accuracy of 3.4% compared with values from invasive measurements. Diagnostics and physiological control algorithms on-board modern LVADs could use CVS models other than those shown here, and the presented approach is easily adaptable to them. The methods also demonstrate how to test the robustness and accuracy of the identification algorithm.

Evidencias de validez y confiabilidad del Inventario de Trastornos de Ansiedad Generalizada en universitarios mexicanos / Evidence of validity and reliability of the Generalized Anxiety Disor-ders Inventory in Mexican university students

El presente estudio analiza las propiedades psicométricas, en hombres y mujeres universitarios, de la versión española propuesta por Blanco et al. (2017) para el Inventario de Trastornos de Ansiedad Generalizada. La mues¬tra total fue de 1220 participantes; 640 mujeres y 580 hombres, con una edad media de 20.40 años (DE= 1.92) y 20.54 años (DE= 2.04) respectivamente. Los análisis factoriales confirmatorios mostraron que una estructura trifactorial (síntomas cognitivos, trastornos del sueño y síntomas somáticos) es viable y adecuada para ambas poblaciones (mujeres y hombres) de acuerdo a los requisitos psicométricos establecidos. Además, la estructura factorial, las cargas factoriales y los interceptos se consideran invariantes en las dos poblaciones; sin embargo, existen diferencias entre las poblaciones para las medias de los factores síntomas cognitivos y síntomas somá¬ticos.

The present study analyses the psychometric properties, in university men and women, proposed for Blanco et al. (2017) to the Spanish version of the Generalized Anxiety Disorder Inventory. The overall sample consisted of 1220 subjects: 640 women and 580 men, with a mean age of 20.40 years (SD= 1.92) and 20.54 years (SD= 2.04) respectively. Psychometric analysis showed that a tri-factorial structure (cognitive symptoms, sleep disorders and somatic symptoms) was viable and adequate for both populations (men and woman) according to the established psychometric requirements. The results showed that factor structure, factor loadings and intercepts of the instrument could be considered invariant across groups; however, there are differences between groups for the means of factors cognitive anxiety and somatic symptoms.

Hybrid Mock Circulatory Loop Simulation of Extreme Cardiac Events.

OBJECTIVE: This paper presents preliminary methods of incorporating the pathological conditions of cardiac arrhythmias and valvular stenosis in hybrid mock circulation loop (hMCL) operation for the enhanced verification and validation of mechanical circulatory support devices such as VADs. METHODS: The MGH/MF Waveform datasets from PhysioNet database (including both nominal and clinically diagnosed arrhythmic ECG measurements) as well as cardiovascular system model updates are used to recreate arrhythmic events and valvular stenosis in vitro. RESULTS: Preliminary results show the hMCL can recreate each tested cardiac event within 2% and 4% mean error for reference pressure tracking in the aortic and left ventricular pressure chambers, respectively. Further, frequency spectrum analysis comparisons using the magnitude-squared coherence analysis shows close alignment between measured arrhythmic and hMCL realized pressure frequency content. CONCLUSION: The generation of cardiac arrhythmias and valvular stenosis around a VAD via both model and acute measurement based methods was achieved. SIGNIFICANCE: Pathological conditions such as cardiac arrhythmias and valvular stenosis are limited in documentation despite the large percentage of patients who experience these events. This paper provides a means to begin incorporating these events into hardware-in-the-loop mock circulatory systems for next generation VAD validation and verification.

Composition and Factorial Invariance for the Assessment of Body Image Dissatisfaction Questionnaire in Mexican Adolescents.

Body image is a mental representation that a person has, which could become a body dissatisfaction due to the pressure exerted by the culture, affecting several life stages specially in adolescents. The aim of this study was to analyze the psychometric properties and factorial invariance of the questionnaire to assess body image dissatisfaction. The sample consisted of 552 Mexican teenagers, 259 female, and 293 male, with a mean age of 12.91 ± 0.96 years. Confirmatory Factor Analyses show that a five-factor structure is viable and adequate. The five-factor structure (perceptual, emotional distress, behavioral, proposal to change, and fear of gaining weight) show adequate fit indices and validity, even though the obtained model does not completely correspond to that proposed by the authors of the scale, it continues to endorse the multifactorial component of body dissatisfaction. On the other hand, the factorial structure, the factor loadings, and the intercepts are considered invariant in both populations; however, there are differences between the populations for the means of the perceptual, emotional distress, and fear of gaining weight factors. This study serves as a premise for future research on the study of instruments for measuring body image in populations with different personal and cultural factors.

Mexican physical education teacher's self-reported and self-perception of teaching style / Auto-percepción y auto-reporte de estilos de enseñanza en profesores de educación física mexicanos / Autorrelato e autopercepção do estilo de ensino do professor mexicano de educação física

ABSTRACT To understand the self-reported and perception of teaching style used among Mexican physical education teachers. Participants included 104 (n=41 females and 63 males) elementary physical education teachers from northern Mexico. Results showed that a traditional teaching style tends to be mainly used either by male and female's physical education teachers. Showing differences between genders and teaching styles. Female teachers tend to combine a traditional teaching style with one that connects with students engaging in physical activity, developing positive values and attitudes. Cultural context plays an important aspect when developing a teaching self-perception.

RESUMEN Conocer el auto reporte y percepción del estilo de enseñanza entre docentes de educación física mexicanos. Participantes incluyeron 104 (n = 41 mujeres y 63 hombres) maestros de educación física básica del norte de México. Los resultados mostraron que un estilo de enseñanza tradicional tiende a ser utilizado principalmente por profesores de educación física, tanto hombres como mujeres. Mostrando diferencias entre géneros y estilos de enseñanza. Las maestras tienden a combinar un estilo de enseñanza tradicional que conecta con los estudiantes a participar en actividad física, desarrollando valores y actitudes positivas. El contexto cultural juega un aspecto importante a la hora de desarrollar una autopercepción docente.

RESUMO Compreender o autorrelato e a percepção do estilo de ensino utilizado por professores de educação física mexicanos. Os participantes incluíram 104 (n = 41 mulheres e 63 homens) professores de educação física elementar do norte do México. Os resultados mostraram que um estilo de ensino tradicional tende a ser usado principalmente por professores de educação física do sexo masculino e feminino. Mostrando diferenças entre gêneros e estilos de ensino. As professoras tendem a combinar um estilo de ensino tradicional com um que conecta os alunos em atividades físicas, desenvolvendo valores e atitudes positivas. O contexto cultural desempenha um aspecto importante no desenvolvimento da autopercepção do ensino.

Índice de asimetría bilateral morfológica de extremidades inferiores y superiores en jugadores de baloncesto universitario / The upper and lower limb bilateral morphological asymmetry index in university basketball players

Introducción: El baloncesto es objeto de múltiples estudios que incluye la valoración mediante tecnologías actuales como la bioimpedancia. Objetivo: Comparar los índices de asimetría (IA) de las extremidades superiores e inferiores en jugadores de baloncesto universitario por nivel deportivo. Método: Se evaluaron 24 jugadores de baloncesto de diferente nivel competitivo, representativo 1) universitario (n = 12) y 2) facultad (n = 12). Se determinó la circunferencia de brazos y piernas, además de masa magra y grasa por bioimpedancia. Se determinó el índice de asimetría de los miembros inferiores y superiores y se compararon por nivel deportivo. Resultados: La comparación de los índices de asimetría entre brazos y piernas en el grupo total identificó diferencias estadísticamente significativas (p < 0,05) en lo referente a la masa grasa, con mayor adiposidad en extremidades superiores, y un índice de asimetría de -10,8. Cuando se compararon las mismas variables en función del nivel deportivo, los jugadores representantes de la universidad mostraron mayores valores (p < 0,05) en el índice de asimetría de la masa total, circunferencias, masa magra y masa grasa. Las comparaciones intergrupales señalan diferencias en los índices de asimetría del brazo vs. la pierna en masa magra para ambos grupos (p < 0,05) mientras que los de la facultad mostraron diferencia también para grasa con índice de asimetría de 18,3 (p < 0,05). Conclusiones: Indistintamente del nivel deportivo, existen diferentes niveles del índice de asimetría entre extremidades superiores e inferiores en el componente de masa grasa, aunque menores valores del índice de asimetría fueron característicos de los individuos de mayor nivel deportivo(AU)

Introduction: Basketball has been the object of many studies, including assessments based on current technologies such as bioimpedance. Objective: Compare the asymmetry indices (AI) for upper and lower limbs in university basketball players. Methods: An evaluation was conducted of 24 basketball players from different competitive levels, representing 1) the university (n = 12) and 2) the school (n = 12). Determination was made of arm and leg circumference, as well as lean mass and fat by bioimpedance. The lower and upper limb asymmetry index was estimated and compared between the competitive levels. Results: Comparison of the arms and legs asymmetry indices in the total group revealed statistically significant differences (p < 0.05) as to fat mass, with greater adiposity in the upper limbs and an asymmetry index of 10.8. Comparison of the same variables between the sports levels found that players representing the university displayed higher values (p < 0.05) in the asymmetry index for total mass, circumferences, lean mass and fat mass. Comparison between the groups found differences in the arm vs. leg asymmetry indices for lean mass in both groups (p < 0.05), whereas the school players also showed differences for fat, with an asymmetry index of 18.3 (p < 0.05). Conclusions: Regardless of the sports level, different asymmetry indices are found between upper and lower limbs as to fat mass, though smaller asymmetry index values were characteristic of individuals from a higher sports level(AU)

How is my teaching? teaching styles among Mexican physical education teachers / Bomo está meu ensino?: estilos de ensino entre professores de educação física mexicanos / ¿Como es mi enseñanza?: estilos de enseñanza entre docentes mexicanos de educación física

Abstract Purpose: To compare teaching styles (TS) and years of experience among Mexican Physical Education (PE) teachers. Method: 129 PE teachers from the City of Chihuahua completed the Teaching Styles in Physical Education questionnaire; average age: 42.3 (±9.6) years; average time teaching PE: 15.7 (±7.9) years. Subjects were divided in 6 groups according to years of experience: -6, 6-11, 12-17, 18-23, 24-29 and 30+. Results: no differences were found in traditional TS among groups, but all PE teachers showed high tendency to use that TS. The 30+ group showed values higher than 6-11 (p<0.05). Conclusion: There is a tendency to implement a traditional teaching style, although years of experience allow PE teachers to use teaching styles that fit students' needs and their interest to participate in Physical Education classes.

Resumo Objetivo: comparar estilos de ensino (EE) e anos de experiência entre professores de Educação Física (EF) mexicanos. Método: 129 professores de EF da cidade de Chihuahua, média de idade: 42,3 anos (± 9,6) anos; experiência como professor de EF: 15,7 (± 7,9) anos; completaram o Questionário sobre EE em EF. Os sujeitos foram divididos em seis grupos de acordo com os anos de experiência: - 6, 6-11, 12-17, 18-23, 24-29 e 30+. Resultados: não foram encontradas diferenças em EE tradicional por grupo, mas todos os professores de EF mostraram tendência elevada a usar esse EE. O grupo 30+ apresentou valores superiores ao grupo 6-11 entre estilo cognitivo e escala criativa (p <0,05). Conclusão: há uma tendência a implementar o EE tradicional, embora os anos de experiência permitam aos professores de EF usar um EE ajustado às necessidades e interesses dos alunos em participar do curso de EF.

Resumen Propósito: comparar estilos de enseñanza (EE) y años de experiencia entre docentes de Educación Física (EF) mexicanos. Método: 129 maestros de EF de la ciudad de Chihuahua, MX, edad: 42,3 (±9,6) años, experiencia como maestro de EF: 15,7 (±7,9) años, completaron el cuestionario de Estilos de Enseñanza en Educación Física. Los sujetos fueron divididos en seis grupos de acuerdo con los años de experiencia: -6, 6-11, 12-17, 18-23, 24-29 y 30+. Resultados: sin diferencias encontradas en grupo de EE tradicional, sin embargo, todos los docentes de EF mostraron alta tendencia al uso de este EE. El grupo de 30+ mostró valores mayores que el grupo 6-11 entre estilo cognitivo y escala creativa (p<0,05). Conclusión: hay una tendencia en implementar el EE tradicional, aunque los años de experiencia permiten que docentes de EF utilicen un EE ajustándose a las necesidades e intereses de los estudiantes en participar en la clase de EF.

Preload Sensitivity with TORVAD Counterpulse Support Prevents Suction and Overpumping.

PURPOSE: This study compares preload sensitivity of continuous flow (CF) VAD support to counterpulsation using the Windmill toroidal VAD (TORVAD). The TORVAD is a two-piston rotary pump that ejects 30 mL in early diastole, which increases cardiac output while preserving aortic valve flow. METHODS: Preload sensitivity was compared for CF vs. TORVAD counterpulse support using two lumped parameter models of the cardiovascular system: (1) an open-loop model of the systemic circulation was used to obtain ventricular function curves by isolating the systemic circulation and prescribing preload and afterload boundary conditions, and (2) a closed-loop model was used to test the physiological response to changes in pulmonary vascular resistance, systemic vascular resistance, heart rate, inotropic state, and blood volume. In the open-loop model, ventricular function curves (cardiac output vs left ventricular preload) are used to assess preload sensitivity. In the closed-loop model, left ventricular end systolic volume is used to assess the risk of left ventricular suction. RESULTS: At low preloads of 5 mmHg, CF support overpumps the circulation compared to TORVAD counterpulse support (cardiac output of 3.3 L/min for the healthy heart, 4.7 with CF support, and 3.5 with TORVAD counterpulse support) and has much less sensitivity than counterpulse support (0.342 L/min/mmHg for the healthy heart, 0.092 with CF support, and 0.306 with TORVAD counterpulse support). In the closed-loop model, when PVR is increased beyond 0.035 mmHg s/mL, CF support overpumps the circulation and causes ventricular suction events, but TORVAD counterpulse support maintains sufficient ventricular volume and does not cause suction. CONCLUSIONS: Counterpulse support with the TORVAD preserves aortic valve flow and provides physiological sensitivity across all preload conditions. This should prevent overpumping and minimize the risk of suction.

A Novel Toroidal-Flow Left Ventricular Assist Device Minimizes Blood Trauma: Implications of Improved Ventricular Assist Device Hemocompatibility.

BACKGROUND: Continuous-flow left ventricular assist devices (LVADs) cause blood trauma that includes von Willebrand factor degradation, platelet activation, and subclinical hemolysis. Blood trauma contributes to bleeding, thrombosis, and stroke, which cause significant morbidity and mortality. The TORVAD (Windmill Cardiovascular Systems, Inc, Austin, TX) is a first-of-its kind, toroidal-flow LVAD designed to minimize blood trauma. We tested the hypothesis that the TORVAD causes less blood trauma than the HeartMate II (Abbott Laboratories, Pleasanton, CA) LVAD. METHODS: Whole human blood was circulated for 6 hours in ex vivo circulatory loops with a HeartMate II (n = 8; 10,000 rpm, 70 ± 6 mm Hg, 4.0 ± 0.1 L/min) or TORVAD (n = 6; 144 rpm, 72 ± 0.0 mm Hg, 4.3 ± 0.0 L/min). von Willebrand factor degradation was quantified with electrophoresis and immunoblotting. Platelet activation was quantified by cluster of differentiation (CD) 41/61 enzyme-linked immunosorbent assay (ELISA). Hemolysis was quantified by plasma free hemoglobin ELISA. RESULTS: The TORVAD caused significantly less degradation of high-molecular-weight von Willebrand factor multimers (-10% ± 1% vs -21% ± 1%, p < 0.0001), accumulation of low-molecular-weight von Willebrand factor multimers (22% ± 2% vs 45% ± 2%, p < 0.0001), and accumulation of von Willebrand factor degradation fragments (7% ± 1% vs 25% ± 6%, p < 0.05) than the HeartMate II. The TORVAD did not activate platelets, whereas the HeartMate II caused significant platelet activation (CD 41/61: 645 ± 20 ng/mL vs 1,581 ± 150 ng/mL, p < 0.001; normal human CD 41/61, 593 ng/mL; range, 400 to 800 ng/mL). Similarly, the TORVAD caused minimal hemolysis, whereas the HeartMate II caused significant hemolysis (plasma free hemoglobin: 11 ± 2 vs 109 ± 10 mg/dL, p < 0.0001; normal human plasma free hemoglobin <4 mg/dL). CONCLUSIONS: The TORVAD design, with markedly lower shear stress and pulsatile flow, caused significantly less blood trauma than the HeartMate II. LVADs with reduced blood trauma are likely to improve clinical outcomes and expand LVAD therapy into patients with less advanced heart failure.

Scaling the Low-Shear Pulsatile TORVAD for Pediatric Heart Failure.

This article provides an overview of the design challenges associated with scaling the low-shear pulsatile TORVAD ventricular assist device (VAD) for treating pediatric heart failure. A cardiovascular system model was used to determine that a 15 ml stroke volume device with a maximum flow rate of 4 L/min can provide full support to pediatric patients with body surface areas between 0.6 and 1.5 m. Low-shear stress in the blood is preserved as the device is scaled down and remains at least two orders of magnitude less than continuous flow VADs. A new magnetic linkage coupling the rotor and piston has been optimized using a finite element model (FEM) resulting in increased heat transfer to the blood while reducing the overall size of TORVAD. Motor FEM has also been used to reduce motor size and improve motor efficiency and heat transfer. FEM analysis predicts no more than 1°C temperature rise on any blood or tissue contacting surface of the device. The iterative computational approach established provides a methodology for developing a TORVAD platform technology with various device sizes for supporting the circulation of infants to adults.

Preservation of native aortic valve flow and full hemodynamic support with the TORVAD using a computational model of the cardiovascular system.

This article describes the stroke volume selection and operational design for the toroidal ventricular assist device (TORVAD), a synchronous, positive-displacement ventricular assist device (VAD). A lumped parameter model was used to simulate hemodynamics with the TORVAD compared with those under continuous-flow VAD support. Results from the simulation demonstrated that a TORVAD with a 30 ml stroke volume ejecting with an early diastolic counterpulse provides comparable systemic support to the HeartMate II (HMII) (cardiac output 5.7 L/min up from 3.1 L/min in simulated heart failure). By taking the advantage of synchronous pulsatility, the TORVAD delivers full hemodynamic support with nearly half the VAD flow rate (2.7 L/min compared with 5.3 L/min for the HMII) by allowing the left ventricle to eject during systole and thus preserving native aortic valve flow (3.0 L/min compared with 0.4 L/min for the HMII, down from 3.1 L/min at baseline). The TORVAD also preserves pulse pressure (26.7 mm Hg compared with 12.8 mm Hg for the HMII, down from 29.1 mm Hg at baseline). Preservation of aortic valve flow with synchronous pulsatile support could reduce the high incidence of aortic insufficiency and valve cusp fusion reported in patients supported with continuous-flow VADs.

Verification of a computational cardiovascular system model comparing the hemodynamics of a continuous flow to a synchronous valveless pulsatile flow left ventricular assist device.

The purpose of this investigation is to use a computational model to compare a synchronized valveless pulsatile left ventricular assist device with continuous flow left ventricular assist devices at the same level of device flow, and to verify the model with in vivo porcine data. A dynamic system model of the human cardiovascular system was developed to simulate the support of a healthy or failing native heart from a continuous flow left ventricular assist device or a synchronous pulsatile valveless dual-piston positive displacement pump. These results were compared with measurements made during in vivo porcine experiments. Results from the simulation model and from the in vivo counterpart show that the pulsatile pump provides higher cardiac output, left ventricular unloading, cardiac pulsatility, and aortic valve flow as compared with the continuous flow model at the same level of support. The dynamic system model developed for this investigation can effectively simulate human cardiovascular support by a synchronous pulsatile or continuous flow ventricular assist device.

Improved left ventricular unloading and circulatory support with synchronized pulsatile left ventricular assistance compared with continuous-flow left ventricular assistance in an acute porcine left ventricular failure model.

OBJECTIVE: Controversy exists regarding the optimal pumping method for left ventricular assist devices. The purpose of this investigation was to test the hypothesis that pulsatile left ventricular assist synchronized to the cardiac cycle provides superior left ventricular unloading and circulatory support compared with continuous-flow left ventricular assist devices at the same level of ventricular assist device flow. METHODS: Seven male pigs were used to evaluate left ventricular assist device function using the TORVAD synchronized pulsatile-flow pump (Windmill Cardiovascular Systems, Inc, Austin, Tex) compared with the Bio-Medicus BPX-80 continuous-flow centrifugal pump (Medtronic, Inc, Minneapolis, Minn). Experiments were carried out under general anesthesia, and animals were instrumented via a median sternotomy. Hemodynamic measurements were obtained in the control state and with left ventricular assistance using the TORVAD and BPX-80 individually. Left ventricular failure was induced with suture ligation of the mid-left anterior descending coronary artery, and hemodynamic measurements were repeated. RESULTS: During left ventricular assist device support, mean aortic pressure and total cardiac output were higher and left atrial pressure was lower with pulsatile compared with continuous flow at the same ventricular assist device flow rate. During ischemic left ventricular failure, pulsatile left ventricular support resulted in higher total cardiac output (5.58 ± 1.58 vs 5.12 ± 1.19, P < .05), higher mean aortic pressure (67.8 ± 14 vs 60.2 ± 10, P < .05), and lower left atrial pressure (11.5 ± 3.5 vs 13.9 ± 6.0, P < .05) compared with continuous flow at the same left ventricular assist device flow rate. CONCLUSION: Synchronized, pulsatile left ventricular assistance produces superior left ventricular unloading and circulatory support compared with continuous-flow left ventricular assist at the same flow rates.