scholarly journals Optimización económica para el cultivo de papa, zanahoria y cebolla en Cartago, Costa Rica

2021 ◽  
Author(s):  
David Barboza-Navarro ◽  
Johanna Solórzano-Thompson ◽  
Javier Paniagua-Molina
Keyword(s):  
Costa Rica ◽  
Programación Lineal

La producción de papa, cebolla y zanahoria es de gran importancia económica en la zona norte de la provincia de Cartago. Por esta razón es necesario procurar la optimización de las tierras agrícolas que permita programar la oferta y cumplir con las necesidades y condiciones del mercado nacional. En este estudio se optimizó la rentabilidad anual de sembrar 2,34 hectáreas de papa, cebolla y zanahoria, mediante un modelo de programación lineal. Este trabajo se llevó a cabo durante el primer semestre de 2019 con productores de la zona y se utilizaron datos de fuentes primarias de instituciones relacionadas con el sector agrícola. Se aplicaron dos escenarios de optimización de la función de rentabilidad a partir de restricciones de área aprovechable, capacidad de mercado y presupuesto. En ambos escenarios fue posible optimizar la función de rentabilidad con toda la tierra aprovechable, se respetó el rezago de los ciclos de cultivo y se utilizó el menor presupuesto disponible. La optimización de la rentabilidad de cada cultivo permitió entender el comportamiento de siembra de los productores para obtener la mayor utilización de los recursos, la mejor distribución de siembra y la mayor rentabilidad posible.

scholarly journals Modelo de programación lineal para minimizar el costo de fertilización granulada de macro nutrimentos en el cultivo de la zanahoria en Costa Rica

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Javier Paniagua Molina
Keyword(s):  
Costa Rica ◽  
Programación Lineal

Se empleó un modelo de programación lineal para minimizar el costo de la fertilización de nutrimentos mayores, N, P, K, Ca y Mg, con la finalidad de buscar mecanismos para mejorar la competitividad de cultivos hortícolas como la zanahoria.El costo mínimo obtenido fue de US$1.601,79 por hectárea, con el empleo de 714,19 kg/ha de 10-30-10, 1026,81 kg/ha de 15-3-31, 401,79 kg/ha de 15-15-15, 244,12 kg/ha de sulfato de magnesio y 525 kg/ha de carbonato de calcio. El rendimiento meta definido fue de 50 t/ha.Estos resultados contrastan con la fertilización tradicional en la zona bajo estudio, en donde predomina el uso de pocas fuentes fertilizantes. 

Identification of Maize Rayado Fino Virus by Immunoelectron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 636-637
Author(s):  
O. E. Bradfute
Keyword(s):  
Electron Microscopy ◽  
Zea Mays ◽  
Costa Rica ◽  
Severe Disease ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Virus Particles ◽  
Far North ◽  
Maize Rayado Fino Virus ◽  
Antibody Coating

Maize rayado fino virus (MRFV) causes a severe disease of corn (Zea mays) in many locations throughout the neotropics and as far north as southern U.S. MRFV particles detected by direct electron microscopy of negatively stained sap from infected leaves are not necessarily distinguishable from many other small isometric viruses infecting plants (Fig. 1).Immunosorbent trapping of virus particles on antibody-coated grids and the antibody coating or decoration of trapped virus particles, was used to confirm the identification of MRFV. Antiserum to MRFV was supplied by R. Gamez (Centro de Investigacion en Biologia Celular y Molecular, Universidad de Costa Rica, Ciudad Universitaria, Costa Rica).Virus particles, appearing as a continuous lawn, were trapped on grids coated with MRFV antiserum (Fig. 2-4). In contrast, virus particles were infrequently found on grids not exposed to antiserum or grids coated with normal rabbit serum (similar to Fig. 1). In Fig. 3, the appearance of the virus particles (isometric morphology, 30 nm diameter, stain penetration of some particles, and morphological subunits in other particles) is characteristic of negatively stained MRFV particles. Decoration or coating of these particles with MRFV antiserum confirms their identification as MRFV (Fig. 4).

Social representations of human rights violations: Further evidence

2001 ◽  
Vol 60 (2) ◽  
pp. 89-98 ◽  
Author(s):  
Alain Clémence ◽  
Thierry Devos ◽  
Willem Doise
Keyword(s):  
Cluster Analysis ◽  
Human Rights ◽  
Costa Rica ◽  
Young People ◽  
Social Representations ◽  
Social Reality ◽  
Questionnaire Study ◽  
Human Rights Violations ◽  
High Tolerance ◽  
Individual Actions

Social representations of human rights violations were investigated in a questionnaire study conducted in five countries (Costa Rica, France, Italy, Romania, and Switzerland) (N = 1239 young people). We were able to show that respondents organize their understanding of human rights violations in similar ways across nations. At the same time, systematic variations characterized opinions about human rights violations, and the structure of these variations was similar across national contexts. Differences in definitions of human rights violations were identified by a cluster analysis. A broader definition was related to critical attitudes toward governmental and institutional abuses of power, whereas a more restricted definition was rooted in a fatalistic conception of social reality, approval of social regulations, and greater tolerance for institutional infringements of privacy. An atypical definition was anchored either in a strong rejection of social regulations or in a strong condemnation of immoral individual actions linked with a high tolerance for governmental interference. These findings support the idea that contrasting definitions of human rights coexist and that these definitions are underpinned by a set of beliefs regarding the relationships between individuals and institutions.

Prevalence and geographic distribution of haemophilia in Costa Rica

2010 ◽  
Vol 30 (S 01) ◽  
pp. S28-S31 ◽  
Author(s):  
J. Arroyo ◽  
L. Salazar-Sánchez ◽  
G. Jiménez-Cruz ◽  
P. Chaverri ◽  
E. Arrieta-Bolaños ◽  
...  
Keyword(s):  
Costa Rica ◽  
Survival Rates ◽  
Coagulation Factors ◽  
Developed Countries ◽  
Health Centers ◽  
Distribution Analysis ◽  
Distribution Maps ◽  
Immunodeficiency Virus ◽  
The Many ◽  
Low Prevalence

SummaryHaemophilia is the most frequent hereditary haemorrhagic illness and it is due to the deficiency of coagulation factors VIII (haemophilia A, HA) or IX (haemophilia B, HB).The prevalence of this disease varies according to the country, those having better survival rates having also higher prevalences. Specifically in Costa Rica, there are around 130 HA and 30 HB families. This study reports the prevalence and a spatial distribution analysis of both types of the disease in this country. The prevalence of haemophilia in this country is 7 cases per 100 000 men, for HA it is 6 cases per 100 000 and for HB it is 1 case per 100 000 male inhabitants. The prevalence of this disease is low when compared with other populations. This low prevalence could be due to the many patients that have died because of infection with human immunodeficiency virus during the 1980s. The prevalence of haemophilia in Costa Rica is almost one half of that present in developed countries. Nevertheless, the ratio between HA and HB follows world tendency: 5 : 1. In this study, nationwide geographical distribution maps were drawn in order to visualize the origin of severe cases and how this influences the pattern of distribution for both types of haemophilia. By means of these maps, it was possible to state that there is no association between the sites of maximum prevalence of mutated alleles and ethnicity. With this study, haemophilia prevalence distribution maps can be used to improve efforts for the establishment of hemophilia clinics or specialized health centers in those areas which hold the highest prevalences in this country. Also, this knowledge can be applied to improve treatment skills and offer the possibility of developing focused genetic counseling for these populations.

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