70 research outputs found
Evaluación de bienestar de vacas lecheras en sistema de producción a pequeña escala aplicando el protocolo propuesto por Welfare Quality®
trabajo de colaboración interinstitucionalLa información de bienestar animal (BA) en las unidades de producción (UP) de México es escasa, por lo que el objetivo de este estudio fue evaluar el grado de bienestar de vacas lecheras en producción, mediante la aplicación del protocolo europeo Welfare Quality® (WQ®) en cuatro municipios del estado de Hidalgo. Se evaluaron 1,187 vacas en producción, secas y vaquillas gestantes, distribuidas en 52 UP, seleccionadas por pertenecer al sistema familiar y participación voluntaria. En los formatos de WQ® se recabó la información por encuesta estructurada, medición de recursos y a partir de la observación animal, con ajustes a las condiciones del sistema de producción y respetando el orden y tiempo sugerido por el protocolo. En el análisis de la información se aplicaron los algoritmos de árbol de decisiones, suma ponderada y funciones I-Spline y la integral de Choquet. La clasificación final coloca a todas las UP como aceptables y corroborado en el simulador de WQ® en línea. La calificación en cada Principio (P) fue de 39 puntos para P1, 48 para P2, 23 en P3 y P4 con 28 puntos. Aun cuando el protocolo es una herramienta útil para la valoración del bienestar animal en el sistema de producción a pequeña escala del altiplano mexicano, la aplicabilidad no es total, por ello se hace necesario el desarrollo de protocolos propios, validados y probados científicamente que representen más fehacientemente la realidad del bienestar animal en este sistema.Proyecto financiado por Fundación Hidalgo Produce A.C
ALMIDÓN DE YUCA MODIFICADO POR COPOLIMERIZACIÓN CON ACRILONITRILO
Se describe el aprovechamiento del almidón de yuca para producir copolímeros de injerto con acrilonitrilo, mediante reacción iniciada por oxidoreducción con sulfato ferroso y peróxido de hidrógeno en medio acuoso.El almidón fue utilizado tanto en forma granular como gelatinizado, haciendo un seguimiento de los efectos de proporción de mezcla de reactivos y las temperaturas del pretratamiento del almidón y del medio reaccionante.Los mejores resultados se presentaron operando con suspensiones de almidón del 8% en peo, gelatinizado a 74 ºC durante 30 minutos y utilizando relaciones en peso de 1,5 acrilonitrilo/almidón y 0,0095 Sulfato Ferroso/Almidón; igualmente una relación volúmetrica de 0,0254 Peróxido/Acrilonitrilo. La copolimerización ocurrió favorablemente a 27 ºC durante 3 horas en atmósfera de Nitrógeno.El copolímero obtenido contiene cerca del 45% en peso de poliacrilonitrilo, el cual fue posteriormente sometido a saponificación convirtiendo los grupos nitrilo a una mezcla de carboxilo y carboxamida, con lo cual el materil exhibe propiedades útiles como absorbente acuoso y como floculante de suspensiones de sólidos.Las pruebas de aplicación como absorbente indican que el copolímero saponificado tiene una capacidad de absorción de 100 mL de agua por gramo y aproximadamente 15 mL de solución de Urea al 1,94% por gramo de copolímero. AbstractStarch derived from native plant manihot esculenta was studied to obtain graft copolymers with acrylonitrile using a Ferrous-hydrogen peroxide initiation system.The effect of concentration, starch pretreatment, reactant ratios and temperature are discussed.The saponified starch-polyacrylonitrile graft copolymers were tested as absorbent products
Differences between adjusted vs. non- adjusted loads in velocity-based training: consequences for strength training control and programming
Strength and conditioning specialists commonly deal with the quantification and
selection the setting of protocols regarding resistance training intensities. Although
the one repetition maximum (1RM) method has been widely used to prescribe exercise
intensity, the velocity-based training (VBT) method may enable a more optimal tool
for better monitoring and planning of resistance training (RT) programs. The aim of
this study was to compare the effects of two RT programs only differing in the training
load prescription strategy (adjusting or not daily via VBT) with loads from 50 to 80%
1RM on 1RM, countermovement (CMJ) and sprint. Twenty-four male students with
previous experience in RT were randomly assigned to two groups: adjusted loads (AL)
(nD13) and non-adjusted loads (NAL) (nD11) and carried out an 8-week (16 sessions)
RT program. The performance assessment pre- and post-training program included
estimated 1RM and full load-velocity profile in the squat exercise; countermovement
jump (CMJ); and 20-m sprint (T20). Relative intensity (RI) and mean propulsive
velocity attained during each training session (Vsession) was monitored. Subjects in the
NAL group trained at a significantly faster Vsession than those in AL (p < 0.001) (0.88 -
0.91 vs. 0.67- 0.68 m/s, with a 15% RM gap between groups for the last sessions), and
did not achieve the maximum programmed intensity (80% RM). Significant differences
were detected in sessions 3- 4, showing differences between programmed and performed
Vsession and lower RI and velocity loss (VL) for the NAL compared to the AL group
(p < 0.05). Although both groups improved 1RM, CMJ and T20, NAL experienced
greater and significant changes than AL (28.90 vs.12.70%, 16.10 vs. 7.90% and -1.99 vs.
- 0.95%, respectively). Load adjustment based on movement velocity is a useful way to
control for highly individualised responses to training and improve the implementation
of RT programs
Sistema de Navegación Reactiva Difusa para Giros Suaves de Plataformas Móviles Empleando el Kinect
Resumen: La navegación en un robot móvil es la habilidad para desplazarse de un lugar a otro dentro de un entorno evitando los obstáculos que se presenten. La autonomía de un robot móvil se basa en su sistema de navegación. La aplicación de técnicas de Inteligencia Artificial como la lógica difusa y el uso de la visión por computadora son dos herramientas empleadas para cumplir esta tarea. En algunos sistemas de navegación la seguridad y la facilidad de operación son factores muy importantes. En estos casos, la tolerancia a la incertidumbre de información, la reacción ante objetos imprevistos, y la navegación mediante giros suaves son argumentos del diseño de estos sistemas. En este artículo se presenta el desarrollo de un sistema de navegación reactiva difusa que emplea los datos de profundidad del sensor Kinect, algoritmos de visión por computadora, y lógica difusa, para generar ángulos de giro suave para la navegación de un robot móvil. En pruebas realizadas con la plataforma móvil ERA-MOBI se observaron giros suaves con un porcentaje de evasión de obstáculos del 85.7%. Palabras clave: navegación reactiva, lógica difusa, Kinect, profundidad promedio, robot móvil
Biology and use of the Pacific fat sleeper Dormitator latifrons (Richardson, 1844): state of the art review
The present work is a review of the literature on the native Mexican fish Dormitator latifrons. The aim is to contribute to the integration and systematization of current knowledge to make it easier to identify existing knowledge gaps and breakthroghs Moreover, promote the successful cultivation and protection of this species whose consumption is increasing in Latin America. A review of the articles related to D. latifrons published in international and regional databases was carried out. The articles reviewed focus on taxonomy and systematics, phylogenetic, geographic distribution, ecology, physiology, reproduction, development, pathology, health, and the technologies used to cultivate this fish species. The conclusion is that, even though the cultivation of D. latifrons is of commercial interest in some countries, there are still significant gaps in our knowledge of biology and, consequently, the domestication potential of the species. Filling these gaps will require systematic research efforts on protecting natural populations and improving mass cultivation techniques.Fil: Vega Villasante, Fernando. Universidad de Guadalajara; MéxicoFil: Ruiz González, Luis E.. Universidad de Guadalajara; MéxicoFil: Chong Carrillo, Olimpia. Universidad de Guadalajara; MéxicoFil: Basto Rosales, Mao E. R.. Tecnológico Nacional de Bahía de Banderas; MéxicoFil: Palma Cancino, David J.. Universidad de Guadalajara; MéxicoFil: Tintos Gómez, Adrián. Universidad Tecnológica de Manzanillo; MéxicoFil: Montoya Martínez, Cynthia E.. Universidad de Guadalajara; MéxicoFil: Kelly Gutiérrez, Liza D.. Universidad de Guadalajara; MéxicoFil: Guerrero Galván, Saúl R.. Universidad de Guadalajara; MéxicoFil: Ponce Palafox, Jesús T.. Universidad Autónoma de Nayarit; MéxicoFil: Zapata, Ana. Universidad de Guadalajara; MéxicoFil: Musin, Gabriela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Badillo Zapata, Daniel. Universidad de Guadalajara; Méxic
Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.
OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age
Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.
Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch
MUSCLE STRENGTH AND GOLF PERFORMANCE: A CRITICAL REVIEW
Golf has become an increasingly popular sport and a growing body of research trying to identify its main physical requirements is being published. The aim of this review was twofold: first, to examine the existing scientific literature regarding strength training and golf in healthy, non-injured, subjects; and second, to reach conclusions that could provide information on how to design more effective strength training programs to improve golf performance as well as directions for future research. Studies which analyzed the relationship between muscle strength, swing performance variables (club head speed, driving distance, ball speed) and skill (handicap, score) were reviewed. Changes in swing performance following different strength training programs were also investigated. Finally, a critical analysis about the methodologies used was carried out. The results of the reviewed studies seem to indicate that: 1) a positive relationship exists between handicap and swing performance (even though few studies have investigated this issue); 2) there is a positive correlation between skill (handicap and/or score) and muscle strength; and 3) there is a relationship between driving distance, swing speed, ball speed and muscle strength. Results suggest that training leg-hip and trunk power as well as grip strength is especially relevant for golf performance improvement. Studies that analyzed variations in swing performance following resistance-only training programs are scarce, thus it is difficult to prove whether the observed improvements are attributable to changes in strength levels. Many of the studies reviewed presented some methodological errors in their design and not all strength assessment protocols seemed appropriate. Further studies should determine muscle strength needs in relation to final swing performance, using well designed experiments and strict isoinertial assessment protocols which adequately relate to specific golf motion, age and skill level. More studies with elite participants, either professional or amateur, would be especially desirable
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