Spatial-Temporal Evolution of Scientific Production about Genetically Modified Maize

Maize is the grain cereal that is the basis of human and animal diets in Mexico and Latin America; it constitutes an essential crop for global food security. The objective of this study was to analyze the spatial–temporal evolution of scientific production on the theme of GMO maize, through a bibliometric analysis of the texts available in the main editorial houses (Elsevier, Scopus, and Springer), open access journal articles database (Conricyt, Scielo, Redalyc, Latindex, Claryvate Analytics, Periodica, and DOAJ), and freely accessible web search engine Google Scholar, to determine the factors that influence the impact of the studies. From 1991 to 2019, 917 texts were found whose spatial–temporal evolution showed a linear growth that concentrated in Latin America (58.56%). The low impact (measured by the number of bibliographic citations) of scientific studies developed in countries of Latin America was related to their publication in journals edited in their own countries and in Spanish, which restricts the constructive criticism of peer review. For the case of Mexico, a spatial discrepancy was also found between research centers and production areas, which limits the transference of technology; and no specialized author in theme of GMO maize was found; the researchers responded to “scientific trends” in agreement with the agrarian policies of the timeS

Spatial Delimitation of Genetic Diversity of Native Maize and Its Relationship with Ethnic Groups in Mexico

Mexico, as a center of origin of maize, presents a high diversity of maize races. With the objective of spatially demarcating regions with high concentration of intraspecific diversity in Mexico, as a fundamental measure for the in situ conservation of their agrobiodiversity, Geographic Information Systems (GIS) tools have been used to generate diversity and richness indexes for 64 maize races cultivated in Mexico, using indexes to demarcate relationships to environmental factors such as temperature, precipitation, and altitude; the presence of indigenous groups; and the type of maize used. These relations allowed defining seven environmental units spatially, with characteristic maize races in each of them, which constitute priority areas for in situ conservation. In addition, a close relationship was found between the diversity of maize races and of ethnic groups, from the center to the south of the country, associated with the differences in maize use in different ethnic groups. This geographical demarcation of races and uses of maize will favor food security through specific measures of in situ conservation, as well as an increase in added value of maize by-products based on specific maize races conserved by local ethnic groupsS

Complex I syndrome in striatum and frontal cortex in a rat model of Parkinson disease

Mitochondrial dysfunction named complex I syndrome was observed in striatum mitochondria of rotenone treated rats (2 mg rotenone/kg, i. p., for 30 or 60 days) in an animal model of Parkinson disease. After 60 days of rotenone treatment, the animals showed: (a) 6-fold increased bradykinesia and 60% decreased locomotor activity; (b) 35-34% decreases in striatum O 2 uptake and in state 3 mitochondrial respiration with malate-glutamate as substrate; (c) 43–57% diminished striatum complex I activity with 60–71% decreased striatum mitochondrial NOS activity, determined both as biochemical activity and as functional activity (by the NO inhibition of active respiration); (d) 34–40% increased rates of mitochondrial O 2 •- and H 2 O 2 productions and 36–46% increased contents of the products of phospholipid peroxidation and of protein oxidation; and (e) 24% decreased striatum mitochondrial content, likely associated to decreased NO-dependent mitochondrial biogenesis. Intermediate values were observed after 30 days of rotenone treatment. Frontal cortex tissue and mitochondria showed similar but less marked changes. Rotenone-treated rats showed mitochondrial complex I syndrome associated with cellular oxidative stress in the dopaminergic brain areas of striatum and frontal cortex, a fact that describes the high sensitivity of mitochondrial complex I to inactivation by oxidative reactions.Fil: Valdez, Laura Batriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Zaobornyj, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Bández, Manuel J.. Universidad de Cádiz; EspañaFil: López Cepero, José María. Universidad de Cádiz; EspañaFil: Boveris, Alberto Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires; ArgentinaFil: Navarro, Ana. Universidad de Cádiz; Españ

Haciendas cafeteras antioqueñas : relaciones técnicas y sociales, 1880-1930

A fines del siglo XIX y primeras décadas del presente se dio, en las haciendas cafeteras antioqueñas, una amplia gama de relaciones técnicas y sociales que son la expresión del carácter diversificado de tales explotaciones agrícolas. En este artículo se analizan los diferentes sistemas de trabajo que se definen a partir del tipo de explotación y se examinan las técnicas empleadas en el montaje de la hacienda, cultivo y procesamiento del grano

Reactions of peroxynitrite in the mitochondrial matrix

Superoxide radical (O2 -) and nitric oxide (NO) produced at the mitochondrial inner membrane react to form peroxynitrite (ONOO-) in the mitochondrial matrix. Intramitochondrial ONOO- effectively reacts with a few biomolecules according to reaction constants and intramitochondrial concentrations. The second-order reaction constants (in M-1 s-1) of ONOO- with NADH (233 ± 27), ubiquinol-0 (485 ± 54) and GSH (183 ± 12) were determined fluorometrically by a simple competition assay of product formation. The oxidation of the components of the mitochondrial matrix by ONOO- was also followed in the presence of CO2, to assess the reactivity of the nitrosoperoxocarboxylate adduct (ONOOCO2 -) towards the same reductants. The ratio of product formation was about similar both in the presence of 2.5 mM CO2 and in air-equilibrated conditions. Liver submitochondrial particles supplemented with 0.25-2 μM ONOO- showed a O2 - production that indicated ubisemiquinone formation and autooxidation. The nitration of mitochondrial proteins produced after addition of 200 μM ONOO- was observed by Western blot analysis. Protein nitration was prevented by the addition of 50-200 μM ubiquinol-0 or GSH. An intramitochondrial steady state concentration of about 2 nM ONOO- was calculated, taking into account the rate constants and concentrations of ONOO- coreactants. (C) 2000 Elsevier Science Inc.Fil: Valdez, Laura Batriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Alvarez, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; ArgentinaFil: Lores Arnaiz, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; ArgentinaFil: Schöpfer, Francisco. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. Laboratorio de Metabolismo del Oxígeno; ArgentinaFil: Carreras, Maria Cecilia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. Laboratorio de Metabolismo del Oxígeno; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Poderoso, Juan José. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. Laboratorio de Metabolismo del Oxígeno; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boveris, Alberto Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; Argentin

Análisis de las características de las antenas logoperiódica y fractal, impresas, en la banda "L" y "S"

Se propone el diseño de dos antenas, denominadas logoperiódica y fractal, ambas impresas, en las bandas de frecuencia L (1-2 GHz) y S (2-4 GHz) y por medio de la simulación conocer las prestaciones con relación al diagrama de radiación, respuesta en frecuencia dentro el ancho de banda previsto, ROE, impedancia de entrada, etc. El objeto es realizar una comparación entre las mismas para determinar la de mejor performance y ser instalada en el equipo electrónico portátil monitor de radiaciones no ionizantes en las bandas de frecuencias "L" y "S". El requerimiento del proyecto impone que la construcción sea compacta y de tamaño reducido, para poder ser utilizada en el dispositivo autónomo antes mencionado. El desarrollo de las antenas impresas y la selección de la más conveniente, integra el Proyecto de Desarrollo Tecnológico y Social ―Diseño y construcción de un equipo electrónico portátil monitor de radiaciones no ionizantes en las bandas de frecuencias "L" y "S"Facultad de Ingenierí