Accuracy of Fitbit Activity Trackers During Walking in a Controlled Setting

Activity trackers are widely used to measure daily physical activity. Many devices have been shown to measure steps more accurately at higher intensities, however, it is also important to determine the accuracy of these new devices at measuring steps while walking at a pace similar to that used during most daily activities. PURPOSE: To assess the accuracy of 6 popular activity trackers at measuring steps while walking on a treadmill. METHODS: Twenty-six college students (Mean±SD; 22.1±3.7yrs; 25.1±4.0kg/m2; 13 male) walked 500 steps at 3mph on a treadmill while wearing 6 different activity trackers (Pedometer, Fitbit Blaze, Charge HR, Alta, Flex, Zip, One). The Charge HR was placed two fingers above the right wrist while the Flex was next to the wrist bone. The Blaze was placed two fingers above the left wrist while the Alta was next to the wrist bone. The Fitbit Zip and the One were aligned with the hipbone on the left and right waistband respectively. Steps were counted by a trained researcher using a hand tally counter. Missing values were replaced with the mean value for that device. Step counts were correlated between Fitbit devices and the pedometer and tally counter using Pearson correlations. Significance was set at p\u3c0.05. Mean bias scores were calculated between the step counts for each device and the tally counter. Mean Absolute Percent Error (MAPE) values were also calculated for each device relative to the tally counter. RESULTS: Fitbit Zip and One were significantly correlated with the tally counter (r=0.50, p\u3c0.05; r=0.68, p\u3c0.01, respectively) while the other devices were not significantly correlated. Mean bias and MAPE values were as follows: Device (Mean Bias/MAPE) Pedometer (-0.2±39.2/3.8±6.8), Blaze (34.5±67.1/9.9±11.3), Charge HR (-12.6±61.5/7.0±10.3), Alta (-85.0±70.8/17.1±14.1), Flex (49.5±242.4/19.7±45.3), Zip (1.8±3.4/0.4±0.6), One (0.2±2.1/0.3±0.3). Fitbit Zip and One were within one half percent of actual steps while wrist-worn Fitbits ranged from 7.0-19.7% from actual step counts. CONCLUSION: Consistent with previous research, activity trackers worn at the waist provide the most accurate step counts compared to wrist-worn models. Differences found in wrist-worn models may result in significant over- or underestimation of activity levels when worn for long periods of time

Comparison of Smartphone Pedometer Apps on a Treadmill versus Outdoors

Previous research has focused on the accuracy of smartphone pedometer apps in laboratory settings, however less information is available in outdoor (free living) environments. PURPOSE: Determine the accuracy of 5 smartphone apps at recording steps at a walking speed in a laboratory versus an outdoor setting. METHODS: Twenty-three healthy college students consented (Mean±SD; 22±3.8yrs; BMI 24.9±4.13kg/m2) to participate in 2 separate visits. During the first visit participants walked 500 steps at 3mph on a treadmill while wearing a pedometer and a smartphone placed in the pocket using 5 pedometer apps concurrently (Moves, Google Fit (G-Fit), Runtastic, Accupedo, S-Health). During the second visit, participants walked 400 meters at 3mph on a sidewalk outside. Actual steps for each visit were recorded using a hand tally counter device. Zero and negative values were replaced with the mean value for that trial. Statistical analyses were performed using IBM SPSS 23.0. Mean bias scores were calculated between the step count for each app and the respective tally count for each trial. Mean bias scores were correlated between trials for each app using Pearson correlations and significance was set at p\u3c0.05. Mean Absolute Percent Error (MAPE) values were also calculated for each app for both trials. RESULTS: G-Fit recorded 2 zero values and 2 negative values and Moves recorded 1 zero value. Mean bias scores were significantly correlated between the indoor and outdoor protocols for the pedometer (r=0.67, p\u3c0.01) and S-Health (r=0.46, p\u3c0.5). The remaining apps were not correlated between protocols. The outdoor protocol producing a greater mean bias for the outdoor protocol for G-Fit, Runtastic, and Accupedo (mean bias ± SD indoor, outdoor; -4.3±53.1, -19.3±120.0; -10.7±63.3, -33.4±118.7; 16.0±143.6, 79.0±75.0; respectively) and a greater mean bias for the indoor protocol for the pedometer, Moves, and S-Health (mean bias indoor, outdoor; -1.4±41.5, 0.0±34.1; -117.4±196.7, -42.2±209.6; 11.3±28.4, 0.0±58.7; respectively). MAPE was below 5% for the pedometer and S-Health for both trials. CONCLUSION: Apps with the lowest error in a controlled setting may be less affected when used in other settings, while apps with greater variation in a controlled setting may be affected when used in a different environment

Apoyo social y autonomía para el ejercicio en espacios abiertos. Medición en adultas mayores de la comunidad

La falta de métodos de medición específicos para población adulta mayor limita el avance en el reconocimiento de factores de riesgo para la pérdida de autonomía secundaria a la insuficiente realización de actividad física. Se propuso evaluar el diseño y adaptación de dos instrumentos: 1) Cuestionario para medir la percepción de autonomía para el ejercicio en espacios abiertos y 2) Adaptación de la Escala de Apoyo Social para el Ejercicio (Pender et al., 1995). Estudio descriptivo analítico, diseño comparativo transversal, realizado con 120 mujeres mayores de 60 años. Los factores que se consideraron de riesgo para la autonomía del ejercicio en espacios abiertos fueron tener más de 80 años, sin obesidad según la masa y grasa corporal, padecer diabetes, cardiopatía, hipertensión y artritis (OR de 1,08 a 1,40). Esto debe considerarse para realizar intervenciones de concientización sobre los beneficios y realización de la actividad física en este grupo poblacional

Dimensions of Exercise Self-efficacy Scale by Type of Activity in Independent Older Adult Women

For cultural reasons, for many women in Mexico the adoption of active behavior was restricted to the execution of tasks at home. It was proposed to analyze the psychometric properties of the Self-efficacy to Regulate Exercise Scale. As a secondary objective, the association of scale dimensions by type of physical activity in older adults independent of the community was analyzed. Instrumental and empirical research with two samples totaling 614 older women (M = 70.27 years, SD = 6.3). The participants present functional independence and cognitive integrity and were assistants of seniors clubs in the urban area. The Self-efficacy to Regulate Exercise Scale and the Physical Activity Scale of the Elderly were applied. Psychometric properties of the scale, descriptive and inferential analyzes with Pearson's correlation matrix are presented. SPSS version 21.0 and LISREL 8.80 were used. The adaptation to Spanish in this population has four dimensions with acceptable psychometric properties: stress, competing demands, external influences and climate. It was estimated an expenditure of 1,25 METs (SD= ,54) of physical activity in the home, 5,83 METs (SD= 4,40) for exercise and 2,09 METs (SD= 1,90) during free time. After the elimination of three items an adjustment model with four dimensions are presented. Directing strategies to increase self-efficacy secondary to external influences could increase the physical activity of this growing population group.Por cuestiones culturales, para muchas mujeres en México la adopción de una conducta activa fue restringida a la ejecución de tareas en el hogar. Se propuso analizar las propiedades psicométricas de la Escala de Autoeficacia para el Ejercicio. Como objetivo secundario, se analiza la asociación de las dimensiones de la escala por tipo de actividad física en adultas mayores independientes de la comunidad. Investigación instrumental y empírica con dos muestras que suman 614 mujeres mayores (M= 70.27 años, DE= 6.3). Las participantes presentan independencia funcional e integridad cognitiva y son asistentes de clubes de adultos mayores del área urbana. Se aplicaron la Escala de Autoeficacia para el Ejercicio y el Cuestionario de Actividad Física de Adultos Mayores. Se presentan propiedades psicométricas de la escala, análisis descriptivos e inferenciales con matriz de correlación de Spearman. Se utilizaron SPSS versión 21,0 y LISREL 8,80. La adaptación al castellano en esta población presenta cuatro dimensiones con propiedades psicométricas aceptables: estrés, demandas en competencia, influencias externas y el clima. Se estimó un gasto de 1,25 METs (DE= ,54) de actividad física en el hogar, 5,83 METs (DE= 4,40) de ejercicio y 2,09 METs (DE= 1,90) del tiempo libre. Se presenta modelo de ajuste y propiedades psicométricas de la Escala de Autoeficacia para el Ejercicio. Dirigir estrategias para incrementar la autoeficacia secundaria a influencias externas pudiera incrementar la actividad física de este creciente grupo poblacional.Por razões culturais, para muitas mulheres no México, a adoção de comportamento ativo restringia-se à execução de tarefas em casa. Foi proposto analisar as propriedades psicométricas da Escala de Autoeficácia para o Exercício. Como objetivo secundário, analisa-se a associação das dimensões da escala por tipo de atividade física em idosos independentes da comunidade. Pesquisa instrumental e empírica com duas amostras, totalizando 614 mulheres mais velhas (M = 70,27 anos, DP = 6,3). Os participantes apresentam independência funcional e integridade cognitiva e são assistentes de clubes idosos na área urbana. Foram aplicadas a Escala de Autoeficácia para Exercício e o Questionário de Atividade Física para Idosos. São apresentadas propriedades psicométricas da escala, análises descritivas e inferenciais com a matriz de correlação de Spearman. Foram utilizadas as versões 21.0 e LISREL 8.80 do SPSS. A adaptação ao espanhol nessa população possui quatro dimensões com propriedades psicométricas aceitáveis: estresse, demandas concorrentes, influências externas e clima. Estima-se uma despesa de 1,25 METs (DP =, 54) de atividade física em casa, 5,83 METs (DP = 4,40) de exercício e 2,09 METs (DP = 1,90) de tempo livre. O modelo de ajuste e as propriedades psicométricas da Escala de Autoeficácia para o Exercício são apresentados. Direcionar estratégias para aumentar a autoeficácia secundária a influências externas pode aumentar a atividade física desse crescente grupo populacional

Aplicación de un instrumento para la estratificación del paciente con enfermedad pulmonar obstructiva crónica descompensada en el Departamento de Urgencias

Fundamento: la enfermedad pulmonar obstructiva crónica constituye un problema de salud pública de enorme magnitud, lo cual no ha pasado inadvertido en el Hospital General Universitario Dr. Gustavo Aldereguía Lima, de Cienfuegos. Objetivo: evaluar el proceso de aplicación de un instrumento para la estratificación del paciente con enfermedad pulmonar obstructiva crónica asistido en el Departamento de Urgencias. Métodos: el instrumento fue aplicado a 192 pacientes ingresados y egresados de la institución con diagnóstico de enfermedad pulmonar obstructiva crónica descompensada, en el periodo comprendido entre mayo de 2010 y abril de 2011; en la evaluación fueron utilizados varios indicadores de proceso y de resultado. Resultados: la utilización del instrumento se convirtió en una acción médica rápidamente incorporada y sistemáticamente empleada, aunque no se acompañó de mejoría progresiva en la calidad de la estratificación. El predominio de pacientes en la clase de riesgo elevado de desenlace adverso y altas probabilidades de recuperación estuvo determinado por un elevado número de pacientes con descompensación moderada y asociación a neumonía o insuficiencia cardiaca, los cuales en su mayoría fueron estratificados como riesgo moderado e ingresados en sala de Medicina, a pesar de lo cual la letalidad en ellos fue relativamente baja, al igual que la frecuencia de traslados a Unidades de Cuidados Intensivos de los pacientes inicialmente admitidos en sala (10 %). Conclusiones: los resultados obtenidos en el comportamiento de la letalidad y del índice de traslado a UCI sugieren la conveniencia de realizar modificaciones al instrumento de estratificación utilizado.</p

Serovariedades y patrones de susceptibilidad a los antimicrobianos de cepas de Salmonella aisladas de alimentos en Cuba Serotypes and antimicrobial susceptibility patterns of Salmonella strains isolated from food in Cuba

Se describen los serotipos de 178 cepas de Salmonella enterica aisladas de alimentos en diferentes regiones de Cuba entre enero de 2008 y diciembre de 2009, y el patrón de susceptibilidad a los antimicrobianos de 100 aislados seleccionados mediante muestreo por estratos. Se identificaron 20 serovariedades de Salmonella entre las que predominaron S. Enteritidis (23%); S. Agona (13,5%) y S. London (11,2%). Del total, 75% de las cepas fueron resistentes o presentaron resistencia intermedia a al menos uno de los fármacos probados, en el siguiente orden, según su frecuencia: tetraciclina (70,7%); ampicilina (22,7%) y ácido nalidíxico (14,7%). Se identificaron 10 patrones de resistencia diferentes y predominaron las cepas resistentes o conresistencia intermedia a un fármaco (89,3%). Tres cepas (S. Infantis, S. Derby y S. Enteritidis) fueron multirresistentes y una, de S. Enteritidis, dio un resultado no sensible al ácido nalidíxico y la ciprofloxacina. Se destaca la necesidad de extremar la vigilancia sanitaria integrada en el país para el control de la salmonelosis.The serotypes of 178 isolates of Salmonella enterica taken from food in different regions of Cuba between January 2008 and December 2009 were identified, and the antimicrobial susceptibility pattern of 100 selected isolates was determined by strata sampling. A total of 20 Salmonella serotypes were identified, with a predominance of S. Enteritidis (23%), S. Agona (13.5%), and S. London (11.2%). Of all the strains, 75% were resistant or presented intermediate resistance to at least one of the drugs tested, in the following order: tetracycline (70.7%), ampicillin (22.7%), and nalidixic acid (14.7%). Ten different resistance patterns were identified. The most frequent patterns corresponded to strains that were either drugresistant or had intermediate resistance (89.3%). Three strains (identified as S. Infantis, S. Derby, and S. Enteritidis) were multiresistant, and one of them, S. Enteritidis, was not sensitive to either nalidixic acid or ciprofloxacin. To control salmonellosis, the importance of maximizing integrated health surveillance is emphasized

Dimensões da escala de autoeficácia do exercício por tipo de atividade em mulheres idosas independentes

Se propuso analizar las propiedades psicométricas de la Escala de Autoeficacia para el Ejercicio. Como objetivo secundario, se analiza la asociación de las dimensiones de la escala por tipo de actividad física en adultas mayores independientes de la comunidad. Investigación instrumental y empírica con dos muestras que suman 614 mujeres mayores (M= 70,27 años, DE= 6,3). Las participantes presentan independencia funcional e integridad cognitiva y son asistentes de clubes de adultos mayores del área urbana. Se aplicaron la Escala de Autoeficacia para el Ejercicio y el Cuestionario de Actividad Física de Adultos Mayores. Se utilizaron SPSS versión 21,0 y LISREL 8,80. La adaptación al castellano en esta población presenta cuatro dimensiones con propiedades psicométricas aceptables: estrés, demandas en competencia, influencias externas y el clima. Se presenta modelo de ajuste y propiedades psicométricas de la Escala de Autoeficacia para el Ejercicio.ABSTRACT: It was proposed to analyze the psychometric properties of the Self-efficacy to Regulate Exercise Scale. As a secondary objective, the association of scale dimensions by type of physical activity in older adults independent of the community was analyzed. Instrumental and empirical research with two samples totaling 614 older women (M= 70,27 years, SD= 6,3). The participants present functional independence and cognitive integrity and were assistants of seniors clubs in the urban area. The Self-efficacy to Regulate Exercise Scale and the Physical Activity Scale of the Elderly were applied.SPSS version 21,0 and LISREL 8,80 were used. The adaptation to Spanish in this population has four dimensions with acceptable psychometric properties: stress, competing demands, external influencesand climate. Directing strategies to increase self-efficacy secondary to external influences could increase the physical activity of this growing population group.RESUMO: Foi proposto analisar as propriedades psicométricas da Escala de Autoeficácia para o Exercício. Como objetivo secundário, analisa-se a associação das dimensões da escala por tipode atividade física em idosos independentes da comunidade. Pesquisa instrumental e empírica com duas amostras, totalizando 614 mulheres mais velhas (M= 70,27 anos, DP= 6,3). Os participantes apresentam independência funcional e integridade cognitiva e são assistentes de clubes idosos na área urbana. Foram aplicadas a Escala de Autoeficácia para Exercício e o Questionário de Atividade Física para Idosos. São apresentadas propriedades psicométricas da escala, análises descritivas e inferenciais com a matriz de correlação de Spearman.Foram utilizadas as versões 21,0 e LISREL 8,80 do SPSS. A adaptação ao espanhol nessa população possui quatro dimensões com propriedades psicométricas aceitáveis: estresse, demandas concorrentes, influências externas e clima. Omodelo de ajuste e as propriedades psicométricas da Escala de Autoeficácia para o Exercício são apresentados

Synthesis and characterization of niobium doped bismuth titanate | Síntesis y caracterización del titanato de bismuto dopado con niobio

Pure and niobium doped bismuth titanate ceramics Bi4Ti3−xNbxO12(Nb − BiT) with x ranging from 0% to 2% are prepared by sol–gel method. Pellets are sintered by pressureless sintering (PLS) and spark plasma sintering (SPS). Raman spectroscopy indicates distortion in the structure due to the substitution of titanium by niobium. X-ray photoelectron spectroscopy (XPS) displays the Nb integration to the bismuth titanate ceramic structure. X-ray diffraction shows no secondary phases and offers clues about crystallographic texturing due to the SPS technique. The shape and size of the grains are strongly influenced by the niobium added to the system as reported by scanning electron microscopy. Ferroelectric hysteresis loops exhibit the effect of the niobium and the texturing on the ferroelectric behavior. Higher values of remanent polarization are reported for PLS samples. In comparison with PLS, higher values ofthe relative permittivity are reported for SPS samples due to the non-homogeneous incorporation of N

Effect of the sintering technique on the ferroelectric and d33 piezoelectric coefficients of Bi0.5(Na0.84K0.16)0.5TiO3 ceramic

In the search of lead-free piezoelectric materials, ceramic processing techniques offer potential tools to increase the piezoelectric and ferroelectric properties in addition to new chemical compositions. Powders of pure BNKT16 (Bi0.5(Na0.84K0.16)0.5TiO3) phase were synthesized by sol-gel method with a low crystallization temperature (750 °C). Ceramic samples were sintered by pressureless sintering (PLS), sinter-forging (SF), and spark plasma sintering (SPS) techniques. Structural, morphological, and chemical characterizations were performed by XRD, Raman, EDS, and SEM. Sintered samples by PLS and SF exhibit rod-like grains associated to bismuth volatility. The highest remanent polarization (11.05 μC/cm2), coercive field (26.2 kV/mm), and piezoelectric coefficient (165 pC/N) were obtained for SF sample. The piezoresponse force microscopy (PFM) analysis shows that the crystallites at the nanoscale exhibit piezoelectric phenomenon and the highest piezoelectric response is reported for PLS sample. The presence of the rhombohedral phase, the increase in grain and crystallite size, and the oriented rod-like inclusions favoring the crystallographic texture are facts that enhance the piezoelectric coefficient for BNKT16 piezoceramics