Gross output and livestock sales modelling in Spanish extensive farms using PLSR

The aim of this paper is to model some production variables in extensive livestock farms located in the dehesa ecosystem. We intend to use not only purely economic variables in the construction of the model, but also structural variables in order to identify the characteristics of the farms that have the higher influence. Another objective is to be able to predict these variables at the farm level, using structural variables that are easy to measure. The data used in this work were obtained from a questionnaire survey to the holders/managers of a sample of 69 dehesa farms in Extremadura (SW Spain). The statistical methodology used for the construction of the model was Partial Least Square Regression (PLSR). It can be concluded that the variables relative to farm intensification, to labour and especially to Iberian pig breeding, are those that take part mainly in the model.dehesa, livestock farming systems, partial least square regression, gross output, Crop Production/Industries, Livestock Production/Industries, Research Methods/ Statistical Methods,

Sustainability of organic and conventional beef cattle farms in SW Spanish rangelands (‘dehesas’): a comparative study

Organic production in Spain has increased substantially in recent years due to several factors, such as the growing interest of the European Union towards preserving sensitive ecosystems; the potential role of organic production in the socio-economic development of rural areas and the growing consumers' demand for safer and higher quality foods. Within this framework, this paper analyzes the beef sector of SW Spanish rangelands (dehesas). These are traditional systems characteristic of the Iberian Peninsula where native herbaceous vegetation and evergreen species of Quercus provide the basis for extensive beef farms. Alt-hough traditional management in dehesa farms is of vital importance for the sustainability of this particular ecosystem, in the last years many farms have turned to organic production, trying to take advantage both of new subsidies and of new market trends.With this study, we try to evalu-ate the sustainability of conventional and organic beef production systems in dehesas in Extre-madura (SW Spain), trying to determine the level these systems are contributing both to the preservation of this sensitive ecosystem and to the socioeconomic development of the region. To this end, we apply a methodological adaptation of the MESMIS methodology to 90 dehesa beef farms located in Extremadura (SW Spain). MESMIS is based on the evaluation of basic attributes of sustainability that allow one to make a simultaneous and comparative analysis of different types of farms. It has been found that organic farms are the most sustainable, obtaining higher scores than con-ventional farms in stability and self-reliance, and similar scores in productivity, adaptability, and equity. Organic dehesa beef farms show little dependence on external products and services and are more adapted to their environment (lower stocking rates for an optimal use of the system's feedstuff production), those being the clues for their enhanced sustainability

Evaluación de la sostenibilidad de explotaciones caprinas extremeñas en áreas desfavorecidas como herramienta de apoyo en la conversión hacia explotaciones ecológicas.

INTRODUCTION: The Ibores-Villuercas region (located in SW Spain) is known for its dairy goat farms producing cheeses of high quality (P.D.O. Queso Ibores). The present study characterizes such farms and assess their sustainability, as a tool to determine which farms present more feasibility to carry out a conversion to the organic system. This conversion could be used as a marketing tool for these farms, and contribute to local development (both economically and socially), ensuring the maintenance of the farms and rural population while enabling the preservation of valuable landscapes. METHODOLOGY: farms where classified using cluster analysis. Later, a sustainability assessment of the clusters (groups of farms) was carried out. Finally, farms' difficulties and advantages producing under the organic model where predicted. RESULTS and DISCUSSION: 3 groups of farms were obtained. Group 1 farms were intensive ones, using highly-productive dairy breeds fed high proportion of concentrates. Group 2 were semi-extensive of higher surface and mixed with sheeps, where autochthonous and allochthonous races are reared, and management is closer to a traditional one. Finally, group 3 was a traditional one, closer to the orgnaic management, with low stocking rates and native breeds feeding local feed resources. Regarding the attributes of sustainability, group 3 showed advantages in terms of self-management, which is important under the organic system and areas of scarcity of feed resources (such as that studied)

Conversión de sistemas de producción caprinos de áreas desfavorecidas a ganadería ecológica

INTRODUCTION: The Spanish goat sector's crisis has led to the abandonment of a large number of farms. At present, sector's expectations are reduced, which threatens farms' permanence. This in turn means a loss of agricultural biodiversity, reduced economic activity and loss of rural population. In this context, it is necessary to implement strategies to ensure farms' continuity . In this sense, the conversion to the organic model is proposed in the farms analyzed. METHODOLOGY: To study the possibility and feasibility of such conversion an analysis of their structure (technical and economic characteristics), an assessment of farms' sustainability (based on social, economic and environmental parameters) has been carried out. For this purpose, the MESMIS Framework was used

Comparative Sustainability Assessment of Extensive Beef Cattle Farms

This chapter analyzes the sustainability of beef cattle systems of the Spanish Rangelands known as “Dehesas”. These are traditional systems of the Iberian Peninsula where native herbaceous vegetation and evergreen species of Quercus provide the basis for extensive livestock farms. These systems are considered as outstanding High Nature Value (HNV) farming systems and the most extensive agroforestry systems in Europe according to CORINE Land Cover. Beef farms in this area show low stocking rates and a small dependence on foodstuff purchases.However, certain changes have occurred in the last decadesdue to the Common Agricultural Policy (CAP). On the one hand, some farms have become more intensified, as a way to maximize the revenues from the CAP subsidies. On the other hand, many farms have turned to organic production, trying to take advantage both of new subsidies and of new market trends. In this regard, the organic livestock farming model is gaining weight as an option for sustainable production since, according to various authors, these systems have advantages over conventional and intensive systems. In fact, organic production in the area has increased substantially in recent years due to several factors, such as the growing interest of the EU towards preserving sensitive ecosystems, the potential role of organic production in the development of rural areas and the growing consumers’ demand for safer and higher quality foods produced under ethical and environmental standards. In this study, we carried out a comparative assessment of the sustainability of different conventional and organic beef production systems located in dehesa rangelands. The systems analyzed were classified as follows. (i) non-organic farms (Conventional); (ii) organic farms that sold calves at weaning age as conventional ones (Organic 1); (iii) organic farms that fattened and sold their calves as organic (Organic 2). An adaptation of the MESMIS multicriteria framework was applied to calculate sustainability indices for each system. The results showed that the Organic 2 farms scored highest on most of the attributes of sustainability, as well as on the environmental and economic dimensions of sustainability. Thus, they were the most sustainable system (66.55%), followed by the Organic 1 (61.04%) and Conventional ones (56.89%). Despite Organic 2 was the most sustainable system, its implementation is complex due to both the high costs of organic inputs and the weak demand for organic beef. The results also showed that all three types of systems need to improve in certain aspects that are crucial in the current and future context of the livestock sector. These aspects are: reducing the dependence on external feed, implementing more environmentally friendly farming practices, and farm diversification

Using a free open source software to teach mathematics

We present the experience of the authors teaching mathematics to freshmen engineering students with the help of the open source computer algebra system Sage. We describe some teaching resources and present an ad hoc distribution of Sage used by the authors

Composition of the Pseudoscalar Eta and Eta' Mesons

The composition of the eta and eta' mesons has long been a source of discussion and is of current interest with new experimental results appearing. We investigate what can be learnt from a number of different processes: V to P gamma and P to V gamma (V and P are light vector and pseudoscalar mesons respectively), P to gamma gamma, J/psi,psi' to P gamma, J/psi,psi' to P V, and chi_{c0,2} to PP. These constrain the eta-eta' mixing angle to a consistent value, phi approx 42 degrees; we find that the c cbar components are lesssim 5% in amplitude. We also find that, while the data hint at a small gluonic component in the eta', the conclusions depend sensitively on unknown form factors associated with exclusive dynamics. In addition, we predict BR(psi' to eta' gamma) approx 1 10^{-5} and BR(chi_{c0} to eta eta') approx 2 10^{-5} - 1 10^{-4}. We provide a method to test the mixing using chi_{c2} to eta eta, eta' eta', and eta eta' modes and make some general observations on chi_{c0,2} decays. We also survey the semileptonic and hadronic decays of bottom and charmed mesons and find some modes where the mixing angle can be extracted cleanly with the current experimental data, some where more data will allow this, and some where a more detailed knowledge of the different amplitudes is required.Comment: 34 pages, 11 figures. v2: version published in JHEP, added substantial section on B and D meson electroweak decays, added comment on psi' to eta(')/eta_c gamma, Figs 5 and 6 split and made clearer, added references, other minor revisions which don't change conclusion

Large N(c′)_(c'), chiral approach to M(n′)_(n') at finite temperature

We study the temperature dependence of the eta and eta[prime] meson masses within the framework of U(3)L×U(3)R chiral perturbation theory, up to next-to-leading order in a simultaneous expansion in momenta, quark masses and number of colors. We find that both masses decrease at low temperatures, but only very slightly. We analyze higher order corrections and argue that large Nc suggests a discontinuous drop of Meta[prime] at the critical temperature of deconfinement Tc, consistent with a first order transition to a phase with approximate U(1)A symmetry

Resección de la primera fila del carpo: indicaciones y resultados

La resección de la primera fila del carpo (RPC) es un conocido procedimiento para conservar la función en muñecas afectadas por procesos degenerativos de la articulación radiocarpiana. En el presente trabajo nuestra experiencia con este tipo de intervención. Material y Métodos: Análisis retrospectivo de pacientes intervenidos en nuestro centro mediante RPC. Se valoraron: datos demográficos, dolor, movilidad y fuerza, y evolución radiológica tras la cirugía. Resultados: 1 pacientes de edad media 58 años, con seguimiento medio de 16 meses. Tras la RPC se observó mejoría del arco de movilidad de la muñeca y de la fuerza de prensión. Cuatro pacientes no tenían dolor. Seis pacientes pudieron reincorporarse a su trabajo. Un paciente evolucionó con rigidez y artrosis radio-hueso grande, que precisó artrodesis al año y medio de la cirugía. Conclusiones: La PRC es una buena intervención para el tratamiento de la artrosis evolucionada de la muñeca.Proximal Row Carpectomy (PRC) is a recognised procedure to preserve motion for wrists which are affected by degenerative diseases at the radiocarpal joint. Material and Methods: Retrospective review of patients subjected to a PRC in our Institution. Demographic data, pain, mobility and grip force, and radiologic evolution before and after surgery were determined. Results: Seven patients, with an average age of 58 years-old. Average follow-up of 16 months. After PRC there was an improvement of mobility and grip force. Four of the seven patients were pain-free. Six patients were able to return to work. One patient developed arthritis of the wrist, being subjected to a wrist arthrodesis one year after surgery. Results: PRC is a good intervention for advanced arthritis of the radiocarpal joint