430 research outputs found

    Alternative treatments in the control of psoroptic mange in a flock of organic production sheep.

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    Abstract The aim of the experiment was to verify the efficacy of the treatment of psoroptic mange in a flock of Churra sheep farmed under organic production conditions, using alternative methods. One group, C Control (N=9), was given no treatment, a second group, TAH Antihomotoxic (N=10), was intramuscularly administered an antihomotoxic preparation every two days, thus receiving a total of seven injections over a two-week period. The third group, TCI Citronella (N=10), was topically administered a 1% solution of 50%essential Citronella Java oil and 50% Potassium Soap twice daily, in each milking, during the two-week period. A fourth group, TCIT Citronella+Thymol (N=10), was topically administered Citronella with 1% mother tincture of Thymol to boost the acaricide activity. The results obtained were analysed by ANOVA for scores and improvement of lesions. At the end of the experiment, TCI and TCIT showed significantly fewer lesions (P<0.05) than the control group and TAH, no differences being detected between the latter two groups. Improvement was significantly higher (P<0.05) in TCI (45%) and TCTT (48%) in comparison with the control group,which only showed 3% improvement. TAH improved by 30% (P<0.05) in comparison with the control group. There were no significant differences between TCI and TCIT. In conclusion, treatment with essential Citronella Java oil and potassium soap can be used as an alternative to conventional methods to control psoroptic mange

    Organic vs Conventional Suckling Lamb Production: Product Quality and Consumer Acceptance

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    Samples of suckling lambs (n=40) of two breeds reared under conventional and organic conditions were analysed to asses physico-chemical characteristics, including instrumental texture, and nutritional quality in terms of fatty acid composition. Consumer acceptance was also studied using the home-use test. Results revealed that organic suckling lamb meat is healthier as shown by the lower saturated fatty acid levels, the higher polyunsaturated fatty acid contents and the higher 6/3 ratiko. The organic meat had lower instrumental hardness, received higher scores in all sensory parameters, and had statistically better fat sensation and higher ratings for overall liking. These results lend support to the notion among consumers that organic products are healthier and tastier

    Consumer Appreciation of Carcass Quality of Organic vs Conventional Suckling Lamb Production

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    Carcass characteristics of sucking lambs (n= 40) of two breeds reared under conventional and organic conditions were analysed including objective and subjective parameters for fatness and conformation, meat and fat colour. Consumer acceptance was also studied using the home-use test. Results showed that the characteristics of the carcass of suckling lamb were similar for both types of production systems pointing out that organic production system did not affect fatness or muscle development. However, organic meat was darker (higher L* and a* values) probably related with the higher amount of exercise, although fat was not more yellow. In contrast consumers did not consider organic meat darker and there were not significant differences in appearance related with the similar conformation. These results reflect that consumer perceive organic meat as at least as good as conventional production not only regarding environmental quality but also regarding carcass quality

    Fracture test of a Gothic ribbed vault

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    A Gothic ribbed vault has been built at the School of Architecture of Madrid in order to investigate the construction complexities of this kind of vaults. The ribbed vault is described in the manuscript of Alonso de Vandelvira, and its shape was reconstructed making using the drawings this architect from the 16th century. The fracture test was carried on by loading the central keystone of the vault until its collapse took place. The experiment was filmed and by doing so, it was possible to observe the failure mechanism of the vault. At the same time, it was interesting to compare this collapse experience with the results obtained using two different me-thods. First, a stability calculation was carried out through graphic statics, and secondly a calcu-lation was performed using the rigid-block analysis method. The focus of this paper is to show and analyze the results of both studies

    Nonequilibrium magneto-conductance as a manifestation of spin filtering in chiral nanojunctions

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    It is generally accepted that spin-dependent electron transmission may appear in chiral systems, even without magnetic components, as long as significant spin−orbit coupling is present in some of its elements. However, how this chirality-induced spin selectivity (CISS) manifests in experiments, where the system is taken out of equilibrium, is still debated. Aided by group theoretical considerations and nonequilibrium DFT-based quantum transport calculations, here we show that when spatial symmetries that forbid a finite spin polarization in equilibrium are broken, a net spin accumulation appears at finite bias in an arbitrary twoterminal nanojunction. Furthermore, when a suitably magnetized detector is introduced into the system, the net spin accumulation, in turn, translates into a finite magneto-conductance. The symmetry prerequisites are mostly analogous to those for the spin polarization at any bias with the vectorial nature given by the direction of magnetization, hence establishing an interconnection between these quantitiesJ.J.P. and M.A.G.-B. acknowledge financialsupport from Spanish MICINN (grant nos. PID2019-109539GB-C43 and TED2021- 131323B-I00), the María de Maeztu Program for Units of Excellence in R&D (grant no. CEX2018-000805-M), Comunidad Autónoma de Madrid through the Nanomag COST-CM Program (grant no. S2018/NMT-4321), Generalitat Valenciana through Programa Prometeo (2021/017), Centro de Computación Científica of the Universidad Autónoma de Madrid, and Red Española de Supercomputació

    Estudio cualitativo sobre los significados de la Medicina Complementaria y Alternativa para el cáncer en estudiantes de Ciencias de la Salud

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    Social representations (SR) have always been a fundamental concept for psychology (Moscovici, 1973). This qualitative study uses the concept of SR, applied to the Health's field; the aim is to analyze the SR of Complementary and Alternative Medicine (CAM) for cancer in students of Health Sciences, using the methodology of thematic analysis. Results indicate that the SR of CAM have been developed based on many different elements, but where prevails an objectification and anchoring of CAM on what is common and familiar, rather than based on scientific knowledge. This to reflect on the training of future professionals and their practices in curing cancer. © 2018 Pontificia Universidad Javeriana.Las representaciones sociales (RS) han sido desde siempre un concepto fundamental para la psicología (Moscovici, 1973). El presente estudio cualitativo utiliza el concepto de RS aplicado al campo de la Salud, con el objetivo de analizar las RS de la Medicina Complementaria y Alternativa (MCA) para el cáncer, en estudiantes de Ciencias de la Salud, utilizando el análisis temático. Los resultados indican que las RS de la MCA se han elaborado con base en elementos muy diversos, pero donde prevale una objetivación y un anclaje de la MCA en lo que es común y familiar, más que en el conocimiento científico. Lo anterior para reflexionar sobre la formación de los futuros profesionales y sus prácticas en la cura del cáncer. © 2018 Pontificia Universidad Javeriana

    Avoided energy cost of producing minerals: The case of iron ore

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    There is growing concern about the decline of the ore grade in mines and the increased energy usage for processing and refining metals. In the limit, where no concentrated deposits exist, minerals must be obtained from bare rock. A method for quantitatively assessing the “free bonus” granted by nature in providing concentrated minerals in mines and thus assessing the quality of the different resources is estimating how much energy is needed to concentrate the minerals, as they are already in mines, from bare rock. This bonus granted by nature reduces the costs of human mining and metallurgical processes, as well as the mining effort required of future generations. In this study, the concentration of high-iron-content minerals in common rocks was investigated via a computational model developed using the HSC software. As expected, the range of results for the specific energy for the concentration of iron from common rocks was considerably higher than the energy required by modern processes. This reveals the need to value current iron deposits and the challenge of developing sustainable methods of metal production to satisfy the needs of the present and future generations

    Comportamiento mecánico de la aleación W+1%Y2O3 en función de la atmósfera y la temperatura

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    Mediante ensayos de flexión en tres puntos se compara y evalúa el comportamiento mecánico de la aleación W- 1wt%Y2O3 con el W puro fabricados ambos mediante HIP. Se ha obtenido la tenacidad de fractura, la resistencia a flexión y el límite elástico en atmósfera oxidante y de vacío en un intervalo de temperaturas comprendido entre -196 ºC, ensayos de inmersión en nitrógeno líquido, y 1200 ºC. Previamente, se ha medido la densidad, la dureza mediante ensayos Vickers y el módulo de elasticidad dinámico de los materiales. Además, la dureza y el módulo de elasticidad se han comparado con los obtenidos mediante ensayos instrumentados de nanoindentación. Finalmente se ha realizado un pequeño estudio de las superficies de fractura de las muestras ensayadas mediante microscopía electrónica de barrido para poder relacionar el modo de rotura de los materiales y las propiedades mecánicas macroscópicas con los micromecanismos de fallo involucrados en función de la temperatura

    Thermodynamic perturbation theory for dipolar superparamagnets

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    Thermodynamic perturbation theory is employed to derive analytical expressions for the equilibrium linear susceptibility and specific heat of lattices of anisotropic classical spins weakly coupled by the dipole-dipole interaction. The calculation is carried out to the second order in the coupling constant over the temperature, while the single-spin anisotropy is treated exactly. The temperature range of applicability of the results is, for weak anisotropy (A/kT << 1), similar to that of ordinary high-temperature expansions, but for moderately and strongly anisotropic spins (A/kT > 1) it can extend down to the temperatures where the superparamagnetic blocking takes place (A/kT \sim 25), provided only the interaction strength is weak enough. Besides, taking exactly the anisotropy into account, the results describe as particular cases the effects of the interactions on isotropic (A = 0) as well as strongly anisotropic (A \to \infty) systems (discrete orientation model and plane rotators).Comment: 15 pages, 3 figure
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