Aflatoxin contamination in corn samples due to environmental conditions, aflatoxin-producing strains, and nutrients in grain grown in Costa Rica

1994 ◽  
Vol 42 (11) ◽  
pp. 2551-2555 ◽  
Author(s):  
Olga M. Viquez ◽  
M. Elena Castell-Perez ◽  
Richard A. Shelby ◽  
George Brown
2014 ◽  
Vol 63 ◽  
pp. 9-14 ◽  
Author(s):  
Cesare Accinelli ◽  
Hamed K. Abbas ◽  
Alberto Vicari ◽  
W. Thomas Shier

2018 ◽  
Vol 66 (4) ◽  
pp. 1421 ◽  
Author(s):  
Vanessa Morales Cerdas ◽  
Lilliana Piedra Castro ◽  
Marilyn Romero Vargas ◽  
Tania Bermúdez Rojas

Environmental quality contributes to the physical and mental well-being of the population. In this way, the green areas (GA) of the cities are essential spaces for coexistence, sports, socialization, recreation, among others. The objective of this research was to determine the environmental conditions of green areas, using indicators as tool for urban management in two cities of Costa Rica. The study area corresponded to the districts of Heredia and Carmen, Costa Rica. The existing GA were determined using Rapid Eye satellite images, 2 012 through spatial analysis and remote sensing. Eleven indicators of urban green areas were applied, the species was identified, the height, the diameter at breast height (DBH) and the number of trees in parks and streets were measured. In addition, surveys were conducted to users of public GA, on issues related to accessibility and use of GA. Five types of GA were identified in Carmen and six were located in Heredia. The percentage of public and private green areas corresponded to 36 % and 64 % in Carmen and 13 % and 87 % in Heredia respectively. The green area per capita (m2 / hab) was 24.6 in Carmen and 2.7 in Heredia. Sixty-two species of trees were identified in the Carmen parks and 23 in Heredia. There were 1 105 trees of 61 species in the streets, sidewalks and avenues of Carmen and 278 individuals of 47 species in Heredia. Regarding the existence of riparian vegetation, it was determined that the Pirro, Burrio, Torres and Negritos streams maintain 82 %, 51 %, 81 % and 14 % of the area of protection of their margins in conforming use. 11 of the public GA’s were evaluated, nine presented a high physical accessibility. In both districts, the surveyed citizens indicated the necessity to have more GA, highlighting the recreational, ecological and touristic value of these spaces. It is concluded that the indicators of urban green areas showed that there are differences between the environmental conditions in both of the evaluated cities. In addition, the applicability of the indicators is feasible as an input for the sustainable environmental management of urban ecosystems.


2020 ◽  
Author(s):  
Julissa Rojas-Sandoval

Abstract Chloris gayana is a robust, strongly stoloniferous grass native to Africa that has been extensively introduced as forage across tropical and subtropical regions. Traits such as its ability to grow in a wide range of environmental conditions, its drought-resistance and its ability to rapidly reproduce both by seeds and vegetatively have facilitated its escape from cultivation and subsequent naturalization. Once established, C. gayana often grows to form almost pure stands that smother native species. Currently, this species is regarded as an invasive in Australia, Spain, Argentina, Paraguay, Mexico, Costa Rica, Cuba, Anguilla, New Caledonia, New Zealand and Hawaii. It is also included in the Global Compendium of Weeds.


Author(s):  
O. E. Bradfute

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).


Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.


2001 ◽  
Vol 60 (2) ◽  
pp. 89-98 ◽  
Author(s):  
Alain Clémence ◽  
Thierry Devos ◽  
Willem Doise

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.


Sign in / Sign up

Export Citation Format

Share Document