3,793 research outputs found

    Effects of caponization on growth performance, carcass and meat quality of mos breed capons rReared in free-range production system

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    21 páginas, 6 tablas, 1 figura.-- This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 LicenseThe effects of caponization on growth performance, carcass characteristics, meat quality and fatty acid profile of breast and drumstick of Mos and Sasso genotypes, reared in free-range production system were examined. A total of 47 birds of Mos breed (19 Castrated and 25 Entire) and 37 of Sasso X-44 (18 Castrated and 19 Entire) slaughtered at 32 weeks were used in this trial. The growth of broilers and the differences between genotypes and caponization effects were modelled by Weibull-growth equation. Capon’s growth was higher than that obtained by roosters and Sasso weight was greater than Mos results (P0.05) by caponization effect, but hardness measured using textural profile analysis was lesser in meat from capons. Finally castration of animals led to important modifications in the intramuscular fat because meat from capons showed significantly lower values for total saturated fatty acids (SFA) and higher polyunsaturated fatty acids (PUFA ). Nutritional indices were also more favorable in capon’s meat, so overall fatty acid profile of capons was desirable from the viewpoint of human nutritionPeer reviewe

    Influence of University Access Test in the teaching methodology of science teachers

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    [Resumen] En este artículo se investigan las percepciones del profesorado de ciencias sobre el efecto de las pruebas de acceso a la universidad, en la metodología docente y en las prácticas de evaluación. En el estudio participaron 120 profesores/as con experiencia docente en asignaturas de ciencias de segundo curso de bachillerato. Como instrumentos de recogida de datos se emplearon cuestionarios abiertos y cerrados, así como entrevistas semiestructuradas, combinándose métodos cualitativos y cuantitativos de análisis de datos. En conjunto, se detecta un efecto inhibitorio en el 2º curso de bachillerato de ciertos recursos y metodologías de enseñanza que habitualmente se consideran de interés en el aprendizaje de las ciencias, favoreciéndose en su lugar enfoques de enseñanza tradicionales, con clases teóricas expositivas. A partir de estos resultados se sugiere la necesidad de una reformulación de las pruebas de acceso y la conveniencia de abordar esta problemática dentro de la formación del profesorado[Abstract] In this work, we investigate he perceptions of science teachers about the effect of the University Access Tests in their teaching methodology and their evaluation practices. The study included 120 teachers with teaching experience, in science subjects of the second-year of secondary education. As data collection instruments, open and closed questionnaires were used, as well as semi-structured interviews, combining qualitative and quantitative methods of data analysis. Overall, an inhibitory effect is detected in the 2nd year of the secondary education of certain teaching resources and methodologies that are usually considered of interest in science learning, favoring instead traditional teaching approaches, with expository theoretical classes. Based on these results, we suggest a reformulation of the access tests and the convenience of addressing this problem within teacher training

    Effect of different lignocellulosic fibres on poly(ε-caprolactone)-based composites for potential applications in orthotics

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    This work compares the mechanical and thermal behaviour of fully biodegradable biocomposites based on polycaprolactone reinforced with three different natural fibres, namely hemp, sisal and coir, for potential applications in the field of orthoses. The same properties were further compared to those of two commercially available materials commonly used in the same prospective field. The results confirmed that the addition of natural fibres, irrespective of the origin of the fibres (leaf, bast or fruit) to a biodegradable matrix allows for significant improvement of the mechanical behaviour of the ensuing composites compared to traditional thermoplastic materials used in orthotics

    A Multiple System of Radio Sources at the Core of the L723 Multipolar Outflow

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    We present high angular resolution Very Large Array multi-epoch continuum observations at 3.6 cm and 7 mm towards the core of the L723 multipolar outflow revealing a multiple system of four radio sources suspected to be YSOs in a region of only ~4 arcsecs (1200 AU) in extent. The 3.6 cm observations show that the previously detected source VLA 2 contains a close (separation ~0.29 arcsecs or ~90 AU) radio binary, with components (A and B) along a position angle of ~150 degrees. The northern component (VLA 2A) of this binary system is also detected in the 7 mm observations, with a positive spectral index between 3.6 cm and 7 mm. In addition, the source VLA 2A is associated with extended emission along a position angle of ~115 degrees, that we interpret as outflowing shock-ionized gas that is exciting a system of HH objects with the same position angle. A third, weak 3.6 cm source, VLA 2C, that is detected also at 7 mm, is located ~0.7 arcsecs northeast of VLA 2A, and is possibly associated with the water maser emission in the region. The 7 mm observations reveal the presence of an additional source, VLA 2D, located ~3.5 arcsecs southeast of VLA 2A, and with a 1.35 mm counterpart. All these radio continuum sources have a positive spectral index, compatible with them being YSOs. We also propose that the high velocity CO emission observed in the region could be the superposition of multiple outflows (at least three independent bipolar outflows) excited by the YSOs located at the core, instead of the previous interpretations in terms of only one or two outflows.Comment: Accepted for publication in The Astrophysical Journal (2007 December 6

    Mirandesa breed calves: growth performance and carcass characterization affected by sex and livestock production system

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    12 páginas, 8 tablas, 2 figuras.-- Under License of Creative Commons Attribution 3.0 LicenseThe effect of sex and livestock production system (LPS) on growth performance and carcass characteristics of Mirandesa breed calves was studied. A total of 2,263 and 60 animals for growth performance and carcass characteristics, respectively were used. Initially, the suitability of several equations to describe the growth of cattle from the Mirandesa variety was studied. In all situations, mathematical models were formulated with parameters of clear biological meaning. Bertalanffy and Gompertz equations were the most satisfactory equations to model the growth of males and females, respectively. Calves from traditional system were 68.61 kg heavier than animals from extensive system. On the other hand, calves from traditional systems showed (P<0.01) higher dressing percentage compared to animals from extensive system. There were significant differences for all morphometric parameters by LPS effect with the exception of internal depth pf chest, whereas sex effect had less importance. The LPS had statistically significant effect in all individual joints in the front quarter and hind quarter with the exception of sirloin and eye of round for front quarter and shoulder and the sum of chuck plus neck in the hind quarter. Finally, the LPS had statistically significant effect in all components of fifth quarter, with the exception of intestines, liver, tail and spleen, whereas sex effect only affected heart proportionPeer reviewe

    Friction mechanisms Wear mechanisms Abrasive wear Adhesive

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    Abstract Friction and wear tests were performed with a number of greases based on biogenic esters and thickened with two metal soaps and a highly dispersed silica acid gel. The series of experiments was performed on a Nonotribometer in material combination of sapphire ball on steel disks with a range of normal loads from 1 up to 500 mN. Results directly show influences of the bulk grease components on frictional and wear behavior. Comparison of frictional and wear results makes manifest that, while in most combinations of base oil and thickener, the highest influence is found in the thickening agent, some combinations are mainly influenced by the base oil. All frictional results along with wear widths and depths as well as micrographs of the prevailing wear mechanisms are presented and discussed

    Effect of biochar amendment on morphology, productivity and water relations of sunflower plants under non-irrigation conditions

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    páginas.-- 6 figuras.-- 2 tablas.-- 56 referencias.-- Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.catena.2016.07.037.Three biochars (B1: pine wood, B2: paper-sludge, B3: sewage-sludge) produced under controlled pyrolysis conditions and one produced in kilns (B4: grapevine wood) were used as organic ameliorants in a Calcic Cambisol, which represents a typical agricultural soil of the Mediterranean region. This field study was performed with plants of sunflower (Helianthus annuus L.) at the experimental station “La Hampa”, located in the Guadalquivir river valley (SW Spain). The soil was amended with doses equivalent to 1.5 and 15 t ha− 1 of the four biochars in two independent plantations. In addition, un-amended plots were prepared in both experiments for comparison purposes. The major goal of this study was the assessment of the effect of biochar amendment on the physiology and development of sunflower plants at field conditions. During most of the growing period plants of un-amended and amended plots showed no stress symptoms either by their appearance or by stress-sensitive biochemical parameters such as the stability of the photosystem II (QY). Biochar addition had no effect on seed germination. Addition of 1.5 t ha− 1 biochar did not significantly change the pH of the soil, its electrical conductivity (EC) or its water holding capacity (WHC). Concomitantly the plant development and plant biomass production remained unaltered. Amendments with 15 t ha− 1 slightly increased the WHC of the soil but showed no lasting impact on the soil pH. It stimulated plant growth and led to a greater leaf area, larger plant stems and wider inflorescences of the sunflower plants than those cultivated on the un-amended soil. At the end of the experiment, biochar amendment of soil caused no significant increase of the total biomass production excepting B4, the biochar with the lowest capacity of water retention, which exhibited the highest vegetative growth and seed production. The lack of rain during the last weeks caused a water shortage in the culture that produced greater QY loss in non-amended plants. Interestingly, better growth of amended plants during the drought period correlated with higher reduction of stomatal conductance, indicating that the greater water use efficiency is at the origin of the better crop performance of biochar-amended plants. This finding points to the agronomic relevance of biochar amendment of Mediterranean rain fed crops.The Marie Skłodowska-Curie actions of the European Union's FP7 People Programme (REA grant agreement no PCIG12-GA-2012-333784-Biocharisma project) and the Spanish Ministry of Economy and Competitiveness (MINECO) (project PCGL2012-37041) are thanked for the financial support of the present study. The Spanish Ministry of Education, Culture and Sport is acknowledged for funding the FPU fellowship (FPU 13/05831) of Marina Paneque, and the contract of Juan De Dios Franco-Navarro (AGL2009-08339/AGR). The European Biochar Network (Biochar as option for sustainable resource management-COST action TD1107) and Bodegas Torres (Spain) are acknowledged for providing the biochar samples. M. Velasco is gratefully acknowledged for her technical assistance at field.Peer reviewe

    Surgical Management of Cavernous Malformations Presenting with Drug-Resistant Epilepsy

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    Cerebral cavernous malformations (CMs) are dynamic lesions characterized by continuous size changes and repeated bleeding. When involving cortical tissue, CMs pose a significant risk for the development of drug-resistant epilepsy, which is thought to be result of an altered neuronal network caused by the lesion itself and its blood degradation products. Preoperative evaluation should comprise a complete seizure history, neurological examination, epilepsy-oriented MRI, EEG, video-EEG, completed with SPECT, PET, functional MRI, and/or invasive monitoring as needed. Radiosurgery shows variable rates of seizure freedom and a high incidence of complications, thus microsurgical resection remains the optimal treatment for CMs presenting with drug-resistant epilepsy. Two thirds of patients reach Engel I class at 3-year follow-up, regardless of lobar location. Those with secondarily generalized seizures, a higher seizure frequency, and generalized abnormalities on preoperative or postoperative EEG, show poorer outcomes, while factors such as gender, duration of epilepsy, lesion size, age, bleeding at the time of surgery, do not correlate consistently with seizure outcome. Electrocorticography and a meticulous removal of all cortical hemosiderin – beyond pure lesionectomy – reduce the risk of symptomatic recurrences

    Minhota breed cattle: Carcass characterisation and meat quality affected by sex and slaughter age

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    7 páginas, 2 tablasThis work focuses on the effect of slaughter age (6 and 9 months) and sex on carcass characteristics and meat quality of the Minhota cattle breed. In this study, data from 52 cattle (34 entire males and 18 females) were used for the carcass and meat characterisation. Regarding carcass characteristics, entire male carcasses (158 kg and 223 kg for animals of 6 and 9 months, respectively), were heavier than female carcasses (130 kg and 161 kg for animals of 6 and 9 months, respectively), with better dressing percentages, increased lengths, thicknesses and depths and compactness indexes. The quality of meat from carcasses of both entire males and females had strong luminosity (L*), a pale pink tone (lower a*-value) and high yellowness. Mean tenderness of Longissimus thoracis, expressed as shear force, was below 5.5 kg/cm2, without significant differences (P > 0.05) between either the slaughter age or sexPeer reviewe
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