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Search Results: 1 - 10 of 270464 matches for " Néstor;Cadena I?iguez "
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Erosión del suelo, escurrimiento y pérdida de nitrógeno y fósforo en laderas bajo diferentes sistemas de manejo en Chiapas, México
Camas Gómez, Robertony;Turrent Fernández, Antonio;Cortes Flores, José Isabel;Livera Mu?óz, Manuel;González Estrada, Adrián;Villar Sánchez, Bernardo;López Martínez, Jaime;Espinoza Paz, Néstor;Cadena Iiguez, Pedro;
Revista mexicana de ciencias agrícolas , 2012,
Abstract: in chiapas, mexico, soil erosion is the main problem affecting the sustainability of hillside lands. as a result, yields and incomes are low, and soil quality continues to decrease. with the aim of finding sustainable technological alternatives, an evaluation was performed on the following systems: maize in conservation tillage (mlc); maize in plant barriers (mbmv) and maize alternated with fruit trees (miaf), in terms of surface runoff, production of sediments and loss of nitrogen and phosphorous from june to november, 2009. the systems were set up in adjacent microbasins, belonging to the basin of river catarina, jiquipilas, chiapas. the soil is a typic haplustepts, with a slope that varies between 3 0 and 40%. out of the total rainfalls, 54% caused soil erosion, 15 % of these with rains of over 40 mm 62% of the total erosion. the runoff coefficient and the specific soil degradation were similar and lower in the micro basins; miaf (12, 5.8 t ha-1) and mbmv (13, 6.3 t ha-1 ) than in the microbasin with mlc (19, 16.8 t ha-1), respectively. in miaf, the runoff filter and total cover provided by maize and bean plants during most of the growth season played an important part in obtaining these results, despite this microbasin presenting a greater slope steepness and length. in regards to the nutrients, there was a greater loss of nitrates in the microbasin with the system mbmv, possibly due to the nitrogen contribution by the leftovers of the pruning ofgliricidia sepium. in regard to phosphorous, the system miaf displayed a greater loss, caused by the yearly phosphoric fertilization performed on the guava trees for three years.
The Cytological Studies on Neglected and Underutilized Cucurbit Species with Special Reference to Chayote, an Under-Exploited Species  [PDF]
Sergio G. Olvera-Vazquez, Jorge Cadena-Iiguez, Syed A. Gilani, Kazuo N. Watanabe
American Journal of Plant Sciences (AJPS) , 2019, DOI: 10.4236/ajps.2019.108091
Cucurbitaceae family contains important economic and medical crops, they can be divided into two categories according to the worldwide consumption, use, and production. The Cucurbit Popular Crops (CuPoC) are comprised of cucumber, the Cucurbita group (pumpkin and squash), melon and watermelon. On the other hand, Neglected and Underutilized Cucurbit Species (NUCuS) group has been used as food sources, medicinal properties and elements in the elaboration of different types of items. The NUCuS is represented in this review work by bitter gourd, bottle gourd, chayote, ridge gourd, and snake gourd, which are recognized mainly in Asia. The center of origin of the majority of NUCuS was proposed to be in the Old World. In contrast, the origin of chayote or Sechiumedule (Jacq.) Sw. was suggested in the New World, precisely in Mesoamerican region based on linguistic uses and distribution of wild relatives. The environmental factors along with artificial selection, production systems and traditional knowledge have been influenced the evolutionary history of NUCuS, Infraspecific variation of chayote has been reported in Mexico over-described varietal groups. These descriptors were determined based on biochemical and morpho-structural traits; however, cytogenetic analyses are scarce. Specifically, chromosome and nuclear content analyses are important to support botanical groups, analyze artificial selection history, developing breeding and conservation programs. The present review paper discusses agronomic and evolutionary importance based on cytological evidence in NUCuS, mainly in the prominent chayote; with the perspective to prompt breeding, conservation, cytology, structural and functional genomics research for its sustainable utilization.
El sistema agropecuario de información en la Frailesca para promover la innovación de tecnologías The farming information system in La Frailesca to promote innovation of technologies
Pedro Cadena Iiguez
Revista mexicana de ciencias agrícolas , 2012,
Abstract: Como una herramienta metodológica de trabajo para promover la innovación de tecnologías agropecuarias, se propuso el Agricultural Knowledge Information System and Rural Development (AKIS-RD) o Sistema de Información Agropecuaria (SAI) en la región del estado de Chiapas conocida como la Frailesca, donde actores promotores y actores receptores, se organizaron y trabajaron bajo una lógica de mercado a través de convenios para promover la innovación de tecnologías ligadas al cultivo del maíz, los resultados basados en una muestra de cinco despachos que están acreditados como agentes PROCREA ante el Banco de México (BM), 52 organizaciones y 194 productores, indican que existen visos de que dichas dinámicas organizacionales sean un sistema agropecuario de Información, sin embargo, la lógica de mercado marcada por los promotores de la estrategia sólo privilegia la plusvalía del dinero, pero no aparecen evidencias de procesos completos de capacitación o educación que empoderen a los actores receptores. El reacomodo de las actividades de los actores, las tareas compartidas entre lo público y lo privado, la organización para promover y recibir tecnología y servicios favorece una mayor participación de los grupos sociales y promueven el desarrollo tecnológico sin que esta sea considerada como innovación. As a metholodogical work tool to promote the innovation of farming technologies, the Agricultural Knowledge Information System and Rural Development (AKIS-RD) or Farming Information System (SAI) was proposed in the region in the state of Chiapas known as La Frailesca, where promoting and recipient actors organized themselves and worked under a market principles, through agreements to promote the innovation of technologies linked to the planting of maize. The results, based on a sample of five offices, that are accredited as PROCREA agents before the Banco de Mexico (BM), 52 organizations and 194 farmers, indicate that there are signs of these organizational dynamics being an agricultural Information system. However, the market principles, marked by the promoters of the strategy, only privilege the added value of money, yet there is no evidence of complete training or education programs that empower the recipient actors. The rearrangement of the actors' activities, the tasks shared between the public and private, the organization to promote and receive technology and services favors a greater participation of social groups and promotes technological development, without it being considered an innovation.
VIPoma pancreático: Caso clínico
Revista médica de Chile , 2010, DOI: 10.4067/S0034-98872010000700008
Abstract: neuroendocrine tumors are uncommon, including vipoma that produces vasoactive intestinal polypeptide. we report a 45-year-old female presenting with a history of diarrhea lasting three months. an abdominal cat scan showed a solid tumor in the body of the pancreas. a fine needle aspiration biopsy of the tumor was compatible with a neuroendocrine tumor. the patient was subjected to a partial pancreatectomy, excising a 4 cm diameter tumor. the pathological study was compatible with a neuroendocrine carcinoma. there was no regional lymph node involvement. during the postoperative period the results of serum vasoactive intestinal polypeptide were received. these were 815.9 pg/ml before surgery and normalized after the operation.
Respuesta a la selección para resistencia a sequía en maíz (Zea mays L.)
Avenda?o Arrazate,Carlos Hugo; Molina Galán,José Domingo; Moreno Pérez,Esaú del Carmen; Cadena Iiguez,Jorge; Aguirre Medina,Juan Francisco; Rincón Enríquez,Gabriel;
Interciencia , 2009,
Abstract: the response to masal selection for components of grain yield, and stability, were studied in two original varieties of corn, zacatecas 58 and cafime, in which 19 and 16 cycles of masal selection for drought resistance were applied, respectively. both genetic materials were evaluated in two localities (montecillo and tecámac, state of mexico) in three soil moisture environments (irrigation, rainfall and drought). the genetic advance estimates for a selection cycle and the stability parameters used indicate that in the drought environment the highest genetic advances in a cycle were found for both varieties, but the largest accumulated profit in units for the evaluated traits, was obtained under irrigation conditions. the selection compounds of the cafime variety were more consistent than those of zacatecas 58. in both varieties, the ear corn average weight increased as the selection cycle number increased and, thus, the coefficient of regression also increased. it is deduced that an increase of visual masal selection increases the yield and the environmental linear sensibility (bi), but not the environmental nonlinear sensibility (s2di). finally, the yield increase and its components were positively correlated with the linear regression coefficient of the yield concerning the selection cycles number, but there was no correlation with the regression deviation.
Diversidad morfológica en colectas de chile guajillo (Capsicum annuum L.) del centro-norte de México
Moreno-Pérez, Esaú del Carmen;Avenda?o-Arrazate, Carlos H;Mora-Aguilar, Rafael;Cadena-Iiguez, Jorge;Aguilar-Rincón, Victor Heber;Aguirre-Medina, Juan Francisco;
Revista Chapingo. Serie horticultura , 2011,
Abstract: in order to characterize morphologically 32 accessions of guajillo chili pepper (capsicum annuum l.) from the states of zacatecas and durango, mexico, an experiment was established in chapingo, mexico, under an experimental design of randomized complete block with three replications. the experimental unit consisted of one row 4 m long and 90 cm wide, with distance of 40 cm between plants. the crop was managed in padded black with silver colored plastic and a fertigation system. quantitative and qualitative characters were evaluated based on the descriptor guide for capsicum of ipgri and analyzed by principal components (pc) and hierarchical clusters (hc). the first three pc explained 58 % of the total quantitative variation among the accessions; the largest contribution to this variation was the characteristics associated with leaf morphology and flower structure (length and width of mature leaf, petiole length, corolla length and corolla width), fruiting days and number of fruits per plant, in addition to phenological variables. through the hc, five groups were formed in the dendrogram of quantitative variables. with regard to qualitative variables, three pc explained 76 % of the variation between accessions; branch density and leaf, tillering, shape of the corolla, fruit color and termination of the fruit tip contributed more to explaining the variation detected among accessions; the hc formed 8 groups. the results indicate that sufficient morphological diversity exists in guajillo chilli to be useful in starting a breeding program.
Test de estimulación intraarterial selectiva con calcio en el diagnóstico de localización de insulinomas: Casos clínicos
Martínez O,Darío; Silva Q,Guillermo; Solís O,Iván; Toloza H,Jorge; Benavides C,Carlos; Hamilton S,James; Osorio G,Fernando; Iiguez V,Germán; Soto I,Néstor;
Revista médica de Chile , 2004, DOI: 10.4067/S0034-98872004000100011
Abstract: insulinoma is the most common neuroendocrine tumor. its clinical manifestations are frequently confounded with neuropsychiatric symptoms, and definitive diagnosis can be delayed for a long time. these tumors are usually small, of less than 2 cm. thus, their preoperative localization is difficult. we report two patients with a clinical diagnosis of insulinoma, in whom the preoperative imaging study was negative. both fulfilled diagnostic criteria, with high serum insulin levels in the presence of a blood glucose of less than 45 mg/dl. the imaging study, including abdominal computed tomography and pancreatic endoscopic ultrasonography did not disclose the location of the tumor. a pancreatic angiography with selective stimulation with intra arterial calcium and venous sampling for insulin measurements, was performed in both patients. this test allowed the exact localization of the tumors and their successful excision. a review of other localization diagnostic tests is done (rev méd chile 2004; 132: 71-5).
Isolation and Characterization of Novel Microsatellite Markers in Chayote [Sechium edule (Jacq.) Sw.]  [PDF]
Ryoko Machida-Hirano, Moisés Cortés-Cruz, Blanca Amalia Amaro González, Jorge Cadena í?iguez, Kazuto Shirata, Kazuo N. Watanabe
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.613203
Abstract: Chayote [Sechium edule (Jacq.) Sw.] is an economically important species in Latin America; however, there are very few reports available regarding its genetic diversity. Out of 11 microsatellite markers isolated, 10 loci provided 1 to 7 alleles per locus in a set of Mexican chayote accessions. Observed and expected heterozygosities for each locus ranged from 0.00 to 0.85 and 0.00 to 0.73, respectively. The overall genetic diversity detected by microsatellites was compared with that detected by P450-based analogue markers, a genome-wide dominant marker. Genetic diversity values obtained by the newly designed microsatellite markers were almost equal to the value estimated by PBA markers, but genetic distances calculated by both marker systems were not significantly correlated. Additional microsatellite markers, which could detect more polymorphisms, may be necessary to analyze the genetic diversity and structure of Mexican chayote collections.
Recycling Agave Bagasse of the Tequila Industry  [PDF]
C. G. Iiguez, C. J. J. Bernal, M. W. Ramírez, N. J. Villalvazo
Advances in Chemical Engineering and Science (ACES) , 2014, DOI: 10.4236/aces.2014.42016

This paper presents an overview of different handling systems and use of the agave bagasse. These systems have appeared from different research works always taking in account the environmental sustainability. It is mentioned that the agave bagasse can be used for animal feeding, for the elaboration of compound materials, as an element for agricultural and hydroponic vegetables cultivation purposes, and also as a means to treat biosolids, vinasses, and bagasses of slaughterhouses and tanneries.

Understanding the induction period of the Belousov-Zhabotinsky reaction
Cadena, Ariel;Pérez, Néstor;ágreda, Jesús A.;Barragán, Daniel;
Journal of the Brazilian Chemical Society , 2005, DOI: 10.1590/S0103-50532005000200014
Abstract: in this paper we present the dependence of the induction time of the belousov-zhabotinsky reaction (bz) on the initial concentrations of malonic acid, bromate and cerium. the experimental results show that the induction time gets larger with bromate increasing and this behaviour does not agree with the mechanistic explanations based on the models proposed for the bz reaction. we propose that a kinetic competition between the bromination of malonic acid and the oxidation of bromomalonic and malonic acids is a way to understand this behaviour. model calculations using the gtf and mbm models support the propose explanation.
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