Assessment of the goals and the policies of the National Development Plan 1979-1982 for beef cattle in Costa Rica

Two aspects of the National Development Plan for beef cattle were considered in this study: goals for production and exports and the policies selected to accomplish those goals;The production goal of bringing forth 91,600 metric tons of meat by 1982 could be fulfilled only if production could grow at a rate of 7.9 percent during the planning period, instead of the 2.7 percent chosen by the Plan. This goal implied the exhaustion by 1982 of the Plan\u27s assessed availability of agricultural land. Export goals were projected with an implicit beef cattle import component, unprovided in the Plan;A reduction in the stock of cattle was experienced for the 1975-78 period as production was outpaced by gains in beef cattle exports. Production increments would imply a reversal in this production-supply relationship through investments in beef cattle during 1979-1982;Production and export goals are in need of revision. In the short run, actions ought to be directed to outweigh the stimuli for exports by devising alternative policies to restrict the supply of cattle. The domestic consumption of meat may have to be suppressed;A subset of policies to accomplish those goals was tested for effectiveness in a partial equilibrium microeconomic context. A linear programming model was developed to aid in the process of policy examination. Methodology was elaborated for use in the model to represent the multi-stage (calf cropping, developing and finishing) multi-period output cycle as a 12-month production process;Five (from fifteen) farms visited were selected for policy examination. These were two small, one medium and two large size farms from a bioclimatic beef cattle region. Three input cost and three production constraint scenarios formed the frame of reference for the examinations of policy effectiveness. There were 45 optimizations of the production programs;Cost of factors was first reduced 20% and then increased by 20%, the calf cropping credit cost was brought to 11% for all farms and the cattle finishing credit cost was increased by 25%. The constraint scenarios were the optimization of the actual production progam, the optimization of that program with a reduction of 25% in calf cropping credit, and the optimization of the original program once the imposed constraints to production were either eliminated or reduced;The policies tested were relatively inefficient for bringing forth beef cattle production, excepting amount of credit, and interest rate differentials were economically unjustified. Inefficiency in resource allocation explained the low production response to factor cost variations. For veterinary medicines the shadow price was 22 times its unit market cost in the medium size farm, and for credit it was 33 times larger than the interest rate in a small farm

Numerical modeling of the electron beam welding and its experimental validation

Electron Beam Welding (EBW) is a highly efficient and precise welding method increasingly used within the manufacturing chain and of growing importance in different industrial environments such as the aeronautical and aerospace sectors. This is because, compared to other welding processes, EBW induces lower distortions and residual stresses due to the lower and more focused heat input along the welding line. This work describes the formulation adopted for the numerical simulation of the EBW process as well as the experimental work carried out to calibrate and validate it. The numerical simulation of EBW involves the interaction of thermal, mechanical and metallurgical phenomena. For this reason, in this work the numerical framework couples the heat transfer process to the stress analysis to maximize accuracy. An in-house multi-physics FE software is used to deal with the numerical simulation. The definition of an ad hoc moving heat source is proposed to simulate the EB power surface distribution and the corresponding absorption within the work-piece thickness. Both heat conduction and heat radiation models are considered to dissipate the heat through the boundaries of the component. The material behavior is characterized by an apropos thermo-elasto-viscoplastic constitutive model. Titanium-alloy Ti6A14V is the target material of this work. From the experimental side, the EB welding machine, the vacuum chamber characteristics and the corresponding operative setting are detailed. Finally, the available facilities to record the temperature evolution at different thermo-couple locations as well as to measure both distortions and residual stresses are described. Numerical results are compared with the experimental evidence.Peer ReviewedPostprint (author's final draft

Towards an Integrative Taxonomy of the Genus Alstroemeria (Alstroemeriaceae) in Chile: A Comprehensive Review

The genus Alstroemeria encompasses approximately 80 species endemic to South America, with 2 centers of diversity (Chile and Brazil). In Chile, Alstroemeria represents one of the most diverse genera of vascular monocotyledons, comprising more than 50 recognized or accepted taxa (36 species, 11 subspecies and 10 varieties) from which ca. 82% are endemic to the Mediterranean zone of central Chile, one of the world’s diversity hotspots. The taxonomy of the genus is very difficult due to the great variability of the vegetative and floral traits. Moreover, a number of taxa have been recently described and several nomenclatural changes have been proposed. In order to elucidate the taxonomy of some Chilean complexes of Alstroemeria, an integrative approach including morphology, colorimetry, cytogenetic, multivariate statistical analyses of morphological variation and DNA-molecular studies have been conducted. In this chapter, we review the literature concerning these approaches; a checklist of the species growing in Chile is provided including all published names, references to the original protologues, accepted names, synonyms and the biogeographic status (endemic or native) of the accepted taxa; maps illustrating the diversity of the genus in South America and its distribution in Chile were constructed

An approach to the seismic hazard at Teruel city associated to the Concud fault (NE Spain)

This paper presents the results ofa probabilistic seismic hazard analysis at Teruel city from seismological and geological information. The characteristic earthquake of the Concud fault (M ~ 6.8; recurrence period = 7.3 ±2.7 ka) has a probabilityof occurrence within a 500-yearperiod ranging from 2.3 to 26.1%. Its parameters fit precisely the magnitude-frequency pattern obtained from the historical seismicity of the Teruel and Jiloca grabens. This coherency supports an estimate of the maximum expectable seism within a 500-yearperiod: M = 5.4± 0.3. Empirical correlations indicate a potential intensity at Teruel overI= VII for this earthquake, and minimum peak ground acceleration ap = 0.105 g, higher than thatspecified by earthquake-resistant building regulationsSe presentan los resultados de un análisis probabilistico de peligrosidad sísmica en el entorno de Teruel a partir de la información geológica y sismológica. El terremoto característico de la falla de Concud (M ~ 6,8;periodo de retorno = 7,3 ±2,7 ka) tiene una probabilidad de ocurrencia en un plazo de 500 años de entre 2,3y26,1 %. Sus parámetros se ajustan bien a la extrapolación de la curva frecuencia-magnitud de la sismicidad histórica en el entorno de las fosas de Teruel yJiloca. En consecuencia, se hace una estimación de la magnitud del seísmo esperable en 500 años: M = 5,4± 0,3. Por correlación empírica se atribuye a éste una intensidad potencial en Teruel por encima de I = VII, y una aceleración de pico mínima ap = 0,105 g, superior a la especificada en la Norma Sismorresistent

¿Son el bajo nivel de condición física y la obesidad dos características del adolescente con síndrome de Down?

Introduction: “Obesity” is considered a feature of youth with DS but whether “low physical fitness” is also a feature is unknown. Objective: The aim of this case-control study was to compare the levels of fatness and fitness in adolescents with and without DS. Methods: Participants included 17 (5 girls) adolescents with DS aged 12-18 years and a control group of 94 (45 girls) adolescents without DS aged 12-16 years. The ALPHA health-related fitness test battery for children and adolescents was selected to assess fatness and fitness in both groups. Results: There were no differences in levels of fatness between groups (all P > 0.27). Adolescents with DS had lower levels of fitness in all the tests than adolescents without DS (all P < 0.001). Conclusion: Adolescents with DS have similar levels of fatness and lower levels of fitness than their peers without DSIntroducción: La obesidad es considerada una característica de los jóvenes con SD, sin embargo se desconoce si la “baja condición física” también lo es. Objetivo: Comparar los niveles de obesidad y condición física en adolescentes con y sin SD. Métodos: Participaron 17 adolescentes (5 niñas) con SD de 12 a 18 años y un grupo control de 94 (45 niñas) adolescentes sin SD de 12-16 años de edad. La batería de condición física ALPHA relacionada con la salud para niños y adolescentes fue seleccionada para evaluar la obesidad y la condición física en ambos grupos. Resultados: No se encontraron diferencias en los niveles de obesidad entre grupos (P > 0,27). Los adolescentes con SD tuvieron niveles más bajos de condición física en todos los test en comparación con los adolescentes sin SD (P < 0,001). Conclusión: Los adolescentes con SD tienen niveles similares de obesidad y menores de condición física que sus compañeros sin SD.The UP&DOWN study was supported by the Spanish Ministry of Economy and Competitiveness (DEP 2010-21662-C04). JRR was supported by a contract from the Spanish Ministry of Science and Innovation (RYC-2010-05957

Large mass movements in relation to deglaciation in the Pyrenees

22 páginasPeer reviewe

Central Spanish Pyrenees: Glacial and periglacial landforms.

32 páginasPeer reviewe