The Effect of Genetic and Infrastructure Investments in Dairy and Beef Producers' Profit in Chile

The objective of this study was to evaluate the effect of infrastructure and genetic improvement investments, promoted by a government program (Programa de Modernizacion Ganadera), in milk and meat producers' profit in Region IX. Using a system of simultaneous equations, the effect of the investment on quality, in the price, in the yield and production cost of milk were estimated. In the case of milk, we reject the nonlinear hypothesis that the elasticities of investment in genetic improvement in gross income and variable costs are equal to zero. The estimation was done using information of 276 producers of the IX Region that participated in the program during the period 1998-99 (17,3 % of the regional population), with information for the years 1998 (baseline), 2001 and 2003. The results indicate that the investment in infrastructure had a positive and statistically significant impact in the quality of milk, which translates into a higher price received by producers. Meanwhile the investment in genetic improvement had a positive and significant effect in milk yield, but also in costs. Similar results were obtained for meat production, but the effect is weaker than in milk production, especially for infrastructure investments.Livestock Production/Industries, O13, Q14, Q16,

The curvature tensor of almost cosymplectic and almost Kenmotsu (\kappa,\mu,\nu)-spaces

We study the Riemann curvature tensor of (\kappa,\mu,\nu)-spaces when they have almost cosymplectic and almost Kenmotsu structures, giving its writing explicitly. This leads to the definition and study of a natural generalisation of the contact metric (\kappa,\mu,\nu)-spaces. We present examples or obstruction results of these spaces in all possible cases

Principales cambios en la epidemiología de las enfermedades infecciosas en el mundo

ResumenEste trabajo revisa el concepto y el impacto de las nuevas enfermedades infecciosas y las razones para su emergencia; a partir de ahí, describe algunas estrategias para su control. Entre estas medidas se encuentra, en primer lugar. el fortalecimiento de los servicios de salud pública, como la vigilancia epidemiológica y los laboratorios de salud pública, que permitan identificar nuevos brotes y nuevas enfermedades infecciosas. En segundo lugar la difusión rápida de los conocimientos generados, hasta las personas encargadas del control de enfermedades. En tercer lugar, la promoción de la investigación en este campo y la formación de personal especializado. Dentro de la investigación es prioritario el desarrollo de nuevas vacunas, potencialmente útiles también para el control de las enfermedades crónicas, consideradas hasta ahora como no infecciosas (úlceras péptica, coronariopatías, etcétera). Por último, se recomienda un “nuevo abordaje epidemiológico”, que integre los aspectos médicos y sociales de las enfermedades. Este abordaje es además el que permite la necesaria colaboración con los profesionales de otros campos, como la inmunología, la microbiología, la clínica y las ciencias sociales.SummaryThis paper reviews the concept and impact of new infectious diseases and the reasons for their emergence; taking that as a start, it describes some strategies to control them. Among these measures we can find, firstly, the strengthening of public health services, such as epidemiological surveillance and public health laboratories, which allow us to identify new outbreaks and new infectious diseases. Secondly, the quick spread of the knowledge that is generated towards the people who are in charge of the control of diseases, and thirdly, the promotion of research in this field and the training of specialized staff. In the field of research, priority is given to the development of new vaccinations that are potentially useful for the control of chronic diseases which were considered until now as non-infectious (peptic ulcer, coronarypathies, etc.). Finally, a new epidemiological approach which integrates medical and social aspects of diseases is advised. Besides, this approach is what allows the necessary collaboration with professionals from other fields, such as immunology, microbiology, clinics and social sciences

Membrana pupilar persistente

La persistencia de la membrana pupilar es una de las alteraciones congénitas oculares más frecuente en los pequeños animales. En este artículo se hace una revisión de las manifestaciones clínicas más frecuentes de esta patología.The persistence of the pupillary membrane is one of the most common congenital ocular anomalies in small animals. In this article a review of the principal clinical signs of this alteration is made

Organocatalyzed Enantioselective Aldol and Henry Reactions Starting from Benzylic Alcohols

Pioneering aldol and Henry reactions starting from benzylic-type alcohols are described. The aldol reaction has been successfully performed following a one-pot strategy starting from alcohols, while the Henry reaction has been carried out following a sequential protocol for the first time. In both processes, enantiomerically enriched products were obtained with good yields and high enantioselectivities. We have also demonstrated that in reactions sensitive to small amounts of acid the use of alcohols instead of aldehydes could be a good solution for improving the results of these reactions. (Figure presented.)

Analysis of hydrogen permeation tests considering two different modelling approaches for grain boundary trapping in iron

The electrochemical permeation test is one of the most used methods for characterising hydrogen diffusion in metals. The flux of hydrogen atoms registered in the oxidation cell might be fitted to obtain apparent diffusivities. The magnitude of this coefficient has a decisive influence on the kinetics of fracture or fatigue phenomena assisted by hydrogen and depends largely on hydrogen retention in microstructural traps. In order to improve the numerical fitting of diffusion coefficients, a permeation test has been reproduced using FEM simulations considering two approaches: a continuum 1D model in which the trap density, binding energy and the input lattice concentrations are critical variables and a polycrystalline model where trapping at grain boundaries is simulated explicitly including a segregation factor and a diffusion coefficient different from that of the interior of the grain. Results show that the continuum model captures trapping delay, but it should be modified to model the trapping influence on the steady state flux. Permeation behaviour might be classified according to different regimes depending on deviation from Fickian diffusion. Polycrystalline synthetic permeation shows a strong influence of segregation on output flux magnitude. This approach is able to simulate also the short-circuit diffusion phenomenon. The comparison between different grain sizes and grain boundary thicknesses by means of the fitted apparent diffusivity shows the relationships between the registered flux and the characteristic parameters of traps

Influence of charging conditions on simulated temperature-programmed desorption for hydrogen in metals

Failures attributed to hydrogen embrittlement are a major concern for metals so a better understanding of damage micro-mechanisms and hydrogen diffusion within the metal is needed. Local concentrations depend on transport phenomena including trapping effects, which are usually characterised by a temperature-programmed desorption method often referred to as Thermal Desorption Analysis (TDA). When the hydrogen is released from the specimen during the programmed heating, some desorption peaks are observed that are commonly related to detrapping energies by means of an analytical procedure. The limitations of this approach are revisited here and gaseous hydrogen charging at high temperatures is simulated. This popular procedure enables attaining high concentrations due to the higher solubility of hydrogen at high temperatures. However, the segregation behaviour of hydrogen into traps depends on charging time and temperature. This process and the subsequent cooling alter hydrogen distribution are numerically modelled; it is found that TDA spectra are strongly affected by the charging temperature and the charging time, both for weak and strong traps. However, the influence of ageing time at room temperature after cooling and before desorption is only appreciable for weak traps

Cold Isostatic Pressing to Improve the Mechanical Performance of Additively Manufactured Metallic Components.

Additive manufacturing is becoming a technique with great prospects for the production of components with new designs or shapes that are difficult to obtain by conventional manufacturing methods. One of the most promising techniques for printing metallic components is binder jetting, due to its time efficiency and its ability to generate complex parts. In this process, a liquid binding agent is selectively deposited to adhere the powder particles of the printing material. Once the metallic piece is generated, it undergoes a subsequent process of curing and sintering to increase its density (hot isostatic pressing). In this work, we propose subjecting the manufactured component to an additional post-processing treatment involving the application of a high hydrostatic pressure (5000 bar) at room temperature. This post-processing technique, so-called cold isostatic pressing (CIP), is shown to increase the yield load and the maximum carrying capacity of an additively manufactured AISI 316L stainless steel. The mechanical properties, with and without CIP processing, are estimated by means of the small punch test, a suitable experimental technique to assess the mechanical response of small samples. In addition, we investigate the porosity and microstructure of the material according to the orientations of layer deposition during the manufacturing process. Our observations reveal a homogeneous distribution independent of these orientations, evidencing thus an isotropic behaviour of the material

On generalized Sasakian-space-forms

We study contact metric and trans-Sasakian generalized Sasakian-space-forms. We also give some interesting examples of generalized Sasakian-space-forms by using warped products and conformal changes of metric.Ministerio de Educación y CienciaFondo Europeo de Desarrollo RegionalPlan Andaluz de Investigación (Junta de Andalucía)Korea Research Foundatio