scholarly journals Análisis del desempeño mecánico de una mezcla asfáltica modificada con fibra de bambú

2021 ◽  
Vol 23 (42) ◽  
pp. 44-52
Author(s):  
Angie Jiménez
Keyword(s):  
Costa Rica

Las organizaciones internacionales como la ONU reconocen la importancia de efectuar acciones contra el cambio climático. Por esta razón, Costa Rica se plantea alcanzar la meta de carbono-neutralidad en los próximos años. A raíz de lo anterior, se ha visto incrementado el uso de materiales biodegradables en diferentes aplicaciones. Al respecto, este artículo presenta una alternativa sostenible a los aditivos de mezclas asfálticas al plantear el uso de bambú para tal fin. Por tanto, uno de los objetivos de esta investigación es potenciar el uso de este cultivo, que genera múltiples beneficios al ambiente como: fijación de carbono, evita erosión en los suelos, genera fuentes de empleo para su cultivo entre otras. Cabe mencionar que las fibras del culmo se utilizan en esta investigación como producto final y no como residuo por lo que, una vez cultivada, la planta vuelve a crecer generando así un ciclo sostenible. Esta investigación presenta el análisis y desempeño mecánico de una mezcla asfáltica modificada con fibra de bambú de la especie guadua angustifolia. El objetivo principal fue evaluar su comportamiento mecánico con la metodología SUPERPAVE. Como resultado se obtuvo una mejoría en la resistencia de la mezcla a la fatiga y al daño por humedad, lo cual es prometedor y abre una posibilidad al uso de fibras en estos materiales.

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.

Osa Peninsula, Costa Rica: A unique opportunity to drill and instrument the seismogenic zone of large megathrust earthquakes

2019 ◽  
Author(s):  
Marino Protti ◽  
◽  
Nathan Bangs ◽  
Peter Baumgartner ◽  
Donald Fisher ◽  
...  
Keyword(s):  
Costa Rica ◽  
Seismogenic Zone ◽  
Osa Peninsula ◽  
Megathrust Earthquakes
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