157 research outputs found

    Efecto del manejo y del temperamento animal sobre indicadores de calidad de la carne bovina

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    The aim of this research was to study the effect of different handling conditions on physiological stress indicators and meat quality of beef cattle by studying animals with different temperaments. Forty animals classified by their temperament (calm and disturbed) were used. They were fed on pastures and finished with a mixed diet of corn grain and pasture. Biochemical indicators of animal stress were measured at slaughter (packed cell volume -PCV-, proteins, glucose, creatinine, alkaline phosphatase -APactivity, cortisol, insulin, glycogen). Also, ultimate pH and instrumental colour were chosen as meat quality markers. Animal temperament showed a significantly increase (p<0.05) on PCV levels and a significantly (p<0.05) decrease on muscle glycogen. Besides, levels of plasma glucose and total proteins showed significant (p<0.05) differences associated to management applied. Meat quality markers (pH and colour) did not show significant differences according to handling conditions or temperament. Mean cortisol levels at the exsanguination time were significantly higher (p<0.05) than the values obtained one week prior to slaughter, which suggests an important effect of stress associated to slaughter procedures. It would be interesting to focus attention on the assessment of acute stress at abattoir, in order to improve handling protocols, and therefore to assure meat quality in Argentinean beef production systems.El objetivo del presente trabajo fue estudiar el efecto de diferentes condiciones de manejo sobre indicadores fisiológicos de estrés y de calidad de carne en bovinos con temperamentos contrastantes. Se utilizaron cuarenta animales clasificados como calmos y excitables. Los mismos fueron alimentados inicialmente a base de pasturas y terminados con una dieta mixta de grano de maíz y pasturas. Se dosaron indicadores bioquímicos de estrés (hematocrito, proteínas plasmáticas, glucosa, creatinina, actividad fosfatasa alcalina, cortisol, insulina, contenido muscular de glucógeno). Como indicadores de calidad de carne se midieron el pH de 24 h y color instrumental. El temperamento animal demostró un incremento significativo (p<0,05) en los niveles de hematocrito y con una disminución significativa (p<0,05) del glucógeno muscular. Los niveles de glucemia y de proteínas totales mostraron modificaciones significativas (p<0,05) asociadas con el manejo. El incremento (p<0,05) en los niveles plasmáticos de cortisol durante la faena, independientemente del tratamiento o el temperamento animal, sugiere un importante efecto estresor por parte del proceso de faena. Sería interesante centrar la atención en el estudio del estrés agudo, a fin de mejorar protocolos de manejo animal, y consecuentemente, optimizar la calidad de la carne asociada en los sistemas de producción de Argentina.Fil: Pighin, D. G.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Agroindustrias. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Moron; ArgentinaFil: Davies, P.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Grigioni, Gabriela Maria. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Agroindustrias. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Moron; ArgentinaFil: Pazos, A. A.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Agroindustrias. Instituto de Tecnología de Alimentos; Argentina. Universidad de Moron; ArgentinaFil: Ceconi, I.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Mendez, Diego Eduardo. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Buffarini, M.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Sancho, A.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Agroindustrias. Instituto de Tecnología de Alimentos; Argentina. Universidad de Moron; ArgentinaFil: Gonzalez, Claudia Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Agroindustrias. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentin

    Experimental Vibration Analysis in the Knowledge Process of a Historic Confined Masonry Building

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    Experimental vibrational analysis is used in the knowledge process of a historic building, made of confined masonry, a construction system suggested in the reconstruction after the 1915 earthquake at Avezzano, Italy. The building was the primary subject of the usual experimental campaign to verify the structural geometry, the characteristics of the materials and the permanent loads. Then, a detailed experimental vibration analysis was carried out. Data were analysed both in the frequency and in the time domains. This combined approach allowed us to point out the importance of the floor deformability on the dynamic behaviour of the structure. A finite element model was set up using the equivalent frame method and calibrated on the basis of the experimental vibrational analysis results. The constitutive law of the confined masonry was fine-tuned, following the literature and present standard suggestions. The pushover analyses allowed us to uncover the behaviour factor of the structure and the seismic safety index, which was found to be quite low and very similar to that obtained via a response spectrum analysis

    Masonry Arch Bridges with Finite Compression Strength Subject to Horizontal Longitudinal Seismic Actions

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    The great diffusion of masonry arch bridges, sometimes of historical interest, requires the development of simple but effective methodologies for a preliminary but reliable evaluation of their static and seismic capacity. In this paper, the behaviour under longitudinal seismic actions is analysed by using the mechanism method. The masonry is supposed to have no tension strength but a rigid–perfect plastic behaviour with finite strength in compression. The arch is subject to permanent loads and to a horizontal acceleration acting in the longitudinal direction, which causes a horizontal inertial loading acting on the arch. Three hypotheses about the effects of the inertial actions of the backfill are considered, which correspond to three different real behaviours. A comprehensive numerical investigation is performed, which allows us to point out the influence of the geometrical and mechanical parameters on the seismic capacity of a masonry arch bridge. The results are given by means of diagrams that can be easily used for a preliminary seismic check of a masonry arch bridge

    Push ‘o ver: in situ pushover tests on as built and strengthened existing brickwork constructions

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    In the last decades several experimental tests were performed to analyse the seismic capacity of unreinforced masonry, mostly involving small size structural elements or small-scale building models, not accounting for the actual complexity of existing constructions. This paper illustrates experimental pushover tests on two very similar portions of an existing masonry building. The first portion was tested as built, while the second one was tested after a strengthening intervention with Composite Reinforced Mortar (CRM) system with Glass Fiber Reinforced Polymer (GFRP) components. The retrofit consisted in the application of a reinforced plaster on both sides of the walls of the first storey and on the external side only of the second storey, a solution that preserves the continuity of use. Comparisons between the experimental response of the two portions as well as the observed behaviour of the intervention at the first storey (both wall sides) and second storey (only outer side) provide very interesting insights and preliminary information on the degree of upgrading, essential steps to support the assessment of seismic vulnerability reduction

    Push ‘o ver. In situ pushover tests on as built and strengthened existing brickwork constructions

    Get PDF
    In the last decades several experimental tests were performed to analyse the seismic capacity of unreinforced masonry, mostly involving small size structural elements or small-scale building models, not accounting for the actual complexity of existing constructions. This paper illustrates experimental pushover tests on two very similar portions of an existing masonry building. The first portion was tested as built, while the second one was tested after a strengthening intervention with Composite Reinforced Mortar (CRM) system with Glass Fiber Reinforced Polymer (GFRP) components. The retrofit consisted in the application of a reinforced plaster on both sides of the walls of the first storey and on the external side only of the second storey, a solution that preserves the continuity of use. Comparisons between the experimental response of the two portions as well as the observed behaviour of the intervention at the first storey (both wall sides) and second storey (only outer side) provide very interesting insights and preliminary information on the degree of upgrading, essential steps to support the assessment of seismic vulnerability reduction

    The 2016–2017 earthquake sequence in Central Italy: macroseismic survey and damage scenario through the EMS-98 intensity assessment

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    In this paper we describe the macroseismic effects produced by the long and destructive seismic sequence that hit Central Italy from 24 August 2016 to January 2017. Starting from the procedure adopted in the complex field survey, we discuss the characteristics of the building stock and its classification in terms of EMS-98 as well as the issues associated with the intensity assessment due to the evolution of damage caused by multiple shocks. As a result, macroseismic intensity for about 300 localities has been determined; however, most of the intensities assessed for the earthquakes following the first strong shock on 24 August 2016, represent the cumulative effect of damage during the sequence. The earthquake parameters computed from the macroseismic datasets are compared with the instrumental determinations in order to highlight critical issues related to the assessment of macroseismic parameters of strong earthquakes during a seismic sequence. The results also provide indications on how location and magnitude computation can be strongly biased when dealing with historical seismic sequences.Presidenza del Consiglio dei Ministri - Dipartimento della Protezione Civile (DPC)Published2407–24314T. Sismicità dell'Italia1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto5SR TERREMOTI - Convenzioni derivanti dall'Accordo Quadro decennale INGV-DPCJCR Journa

    Parent-Related Normative Perceptions of Adolescents and Later Weight Control Behavior: Longitudinal Analysis of Cohort Data From Brazil

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    Purpose Body image-related norms can be imposed by parents and can shape adolescents' body satisfaction in consequential ways, yet evidence on long-term effects is scarce. Longitudinal data from a country with strong body image focus provided a unique opportunity to investigate long-term influences of normative parent-related perceptions. Methods Multinomial logistic regression was used on data from a 1993 birth cohort in Brazil to investigate the association of normal-body mass index (BMI) adolescents' perception of their parent's opinion of their weight at age 11 years with their weight control attempts at 18 years, testing a mediating role for body dissatisfaction at age 15 years. All models controlled for body dissatisfaction at age 11 years and BMI change between ages 11 and 15 years. Results A total of 1150 boys and 1336 girls were included. Girls were more likely than boys to diet without nutritionist advice to lose weight (51.5% vs. 34.3% among boys) and use medication to gain weight (12.7% vs. 4.2%). Normal-BMI adolescents who reported at age 11 years that their parents thought they were thin had higher odds of feeling thinner than ideal at age 15 years (odds ratio 2.8, 95% confidence interval 1.8-3.2; and odds ratio 2.0, 95% confidence interval 1.5-2.7) among boys and girls, respectively). Feeling thinner than ideal at age 15 years was associated among girls with higher odds of weight gain attempts at age 18 years. Similar patterns appeared among girls reporting that their parents thought they were fat at age 11 years, feeling fatter than ideal at age 15 years and having higher odds of weight loss attempts at age 18 years. Body dissatisfaction was a statistically significant mediator among girls but not boys. Conclusions A long-term influence of parent-related perceptions via a likely trajectory of body dissatisfaction is evident among girls
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