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Search Results: 1 - 10 of 210690 matches for " Raúl Mancilla "
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Evaluación de terrazas de banco para plantaciones forestales comerciales
Mancilla Villa, Oscar Raúl;Oropeza Mota, José Luis;Martínez Menes, Mario;
Ciencia forestal en México , 2009,
Abstract: as an option to face the severe erosion problem that prevails in méxico, a project of bench terraces for commercial forest plantations was carried out in valle de bravo, estado de méxico. the technical efficiency of the project was assessed as well as its financial feasibility. field work was done from january to august, 2007. vertical and horizontal ranges between the benches were based upon the following criteria: rainfall, dominant slopes (15 and 30 per cent), soil texture and the foresters' needs. seventy 3 mx0.45 mx .90 m terraces were built in 4 ha, where 3,757 commercial trees were planted. in order to know their technical efficiency, infiltration, superficial draining and the sediments in plots with and without 0.15 m2 terraces were measured, under simulation rainfall of 140 mmh-1 intensity. soil erosion was estimated through the universal soil loss equation. terraces showed an efficiency of 99.09 per cent for erosion control, 43.6 per cent for infiltration increment, 74 per cent of runoff reduction and 46.6 per cent of sediment loss. in regard to financial feasibility, it was found a cost-benefit relation of 2.37, with a net present value of $ 7 800 318.77, and an internal rate of return of 129%. it was concluded that the implementation of bench terraces for commercial forest is a technically efficient financially feasible possibility.
Determinación de anticuerpos anti-PPD en hatos lecheros con distintas prevalencias de tuberculosis bovina en México
Ciro Estrada Chávez,Raúl Mancilla,Camila Arriaga Díaz,Rafael Pérez González
Veterinaria México , 2001,
Abstract: Se evaluó mediante ELISA la respuesta de anticuerpos contra el derivado proteínico purificado de M. bovis (PPD) en hatos con distintas prevalencias de tuberculosis. En el ganado libre de tuberculosis, los valores de densidad óptica fueron significativamente menores a los obtenidos en hatos controlados, infectados y en bovinos con tuberculosis confirmada. Los niveles más altos de anticuerpos se encontraron principalmente en sueros obtenidos del ganado tuberculoso y en los hatos infectados. Sin embargo, algunos bovinos dentro del grupo testigo, sin individuos reactores a la tuberculina por espacio de un a o, mostraron valores altos en el ELISA, lo que sugiere la presencia de una infección residual en esos hatos. Dos de los títulos más altos de anticuerpos se encontraron en dos animales con tuberculosis, sin reacción a la tuberculina, confirmando la utilidad del ELISA con PPD como antígeno para identificar animales anérgicos. Los anticuerpos anti-PPD podrían ayudar a verificar la situación epidemiológica de la tuberculosis en hatos bajo control de la campa a de erradicación.
The 19 kDa Mycobacterium tuberculosis Lipoprotein (LpqH) Induces Macrophage Apoptosis through Extrinsic and Intrinsic Pathways: A Role for the Mitochondrial Apoptosis-Inducing Factor
Alejandro Sánchez,Patricia Espinosa,Teresa García,Raúl Mancilla
Clinical and Developmental Immunology , 2012, DOI: 10.1155/2012/950503
Abstract:
The 19?kDa Mycobacterium tuberculosis Lipoprotein (LpqH) Induces Macrophage Apoptosis through Extrinsic and Intrinsic Pathways: A Role for the Mitochondrial Apoptosis-Inducing Factor
Alejandro Sánchez,Patricia Espinosa,Teresa García,Raúl Mancilla
Journal of Immunology Research , 2012, DOI: 10.1155/2012/950503
Abstract: We describe the association of caspase-dependent and caspase-independent mechanisms in macrophage apoptosis induced by LpqH, a 19?kDa Mycobacterium tuberculosis lipoprotein. LpqH triggered TLR2 activation, with upregulation of death receptors and ligands, which was followed by a death receptor signaling cascade with activation of initiator caspase 8 and executioner caspase 3. In this caspase-mediated phase, mitochondrial factors were involved in loss of mitochondrial transmembrane potential ( ), release of cytochrome c, and caspase 9 activation. Interestingly, a caspase-independent pathway was also identified; by immunoblot, the mitochondrial apoptosis inducing factor (AIF) was demonstrated in nuclei and cytosol of LpqH-treated macrophages. Confocal microscopy revealed translocation of AIF to the nuclei of the majority of apoptotic cells. These findings emphasize the complex and redundant nature of the macrophage death response to mycobacteria. 1. Introduction Macrophage (MO) apoptosis during Mycobacterium tuberculosis (Mtb) infection has focused much attention on its possible role in disease pathogenesis. A number of findings support this view; it has been shown that virulent mycobacterial strains are less apoptogenic than their attenuated counterparts [1] and MO proapoptotic genes are downregulated by virulent strains while the opposite occurs with avirulent mycobacteria [2]. In contrast with latent infection, in active TB patients the expression of genes that promote apoptosis is diminished [3]. These data and the identification of genes that inhibit MO apoptosis in some Mtb mutants [4] have added further support to the view that the ability of Mtb to prevent the apoptotic death of host cells is a virulence trait aimed to preserve its cellular niche. On the other hand, that MO apoptosis represents an innate immune response of the host is suggested by decreased viability of bacilli in apoptotic MO [5–7]. There is also evidence that dendritic cells that have ingested apoptotic MO infected by Mtb can activate T cells through a process known as cross-priming which results in the activation of CD8+ T cells [7, 8]. It is also of interest the identification of Mtb proapoptotic mutants that induce higher T cell immunity which favors the control of infection [9]. Knowledge about the mechanisms involved in the death of mycobacteria-infected MOs has greatly increased during the last decade. Initially, it was characterized as extrinsic type, caspase-dependent apoptosis with TNF-α activation [10, 11]. More recent studies have come to show that MO apoptosis in
Tricobezoar como causa de oclusión intestinal alta. Informe de un caso y revisión de la literatura
Corona-Cruz, José Francisco;Sánchez-Lozada, Raúl;Gracida-Mancilla, Noé Isaías;Palomeque-López, Antonio;Vega Chavaje, Gerardo Ricardo;
Gaceta médica de México , 2005,
Abstract: background: the trichobezoars are conglomerates of hair ingested by a person. they are located in the stomach, although they can extend also to the small bowel. they are common in children and adolescents, and 90% of the patients are women. an occasional complication is mechanical obstruction, usually at the gastric level or in the small bowel. it is extremely rare to find trichobezoars in the small bowel without a gastric component. case report: a 18 years old female patient was admitted for small bowel obstruction. three weeks before she had underwent appendectomy. laparotomy was performed identifying three trichobezoars occluding the jejune, without evidence of gastric bezoars. the bezoars were extracted by enterotomy. no post operatory complications were presented. conclusions: trichobezoars are a rare entity that may be complicated by bowel obstruction. the discovery of trichobezoars in the bowel may be due to primary formation, which is improbable, or to fragmentation in the stomach followed by migration of the fragments, which in the case presented could be favored by the patient's previous operation.
METALES PESADOS TOTALES Y ARSéNICO EN EL AGUA PARA RIEGO DE PUEBLA Y VERACRUZ, MéXICO
óscar Raúl MANCILLA-VILLA,Héctor Manuel ORTEGA-ESCOBAR,Carlos RAMíREZ-AYALA,Ebandro USCANGA-MORTERA
Revista internacional de contaminación ambiental , 2012,
Abstract: Los altos niveles de concentración de metales pesados en agua utilizada para riego representan un problema importante para la agricultura y la salud humana, así como para la biodiversidad, por tal motivo se realizó el presente trabajo con relación a la calidad del agua en los estados de Puebla y Veracruz, México. El estudio se llevó a cabo de noviembre de 2009 a marzo de 2010, se tomaron 91 muestras de agua duplicadas. Se analizaron el potencial hidrógeno (pH), la conductividad eléctrica (CE), As y metales pesados totales: Cd, Cr, Cu, Hg, Ni, Pb y Zn. Los metales pesados se determinaron mediante el uso de un ICP ("Inductively Coupled Plasma") Pekin Elmer Optima 5300, utilizándose la metodología recomendada por la EPA (Environmental Protection Agency) y APHA (American Public Health Association). Se comparó la calidad del agua superficial con los criterios de la NOM-001-ECOL-1996, de EPA (1986), de SEDUE (1989) y la modificación a la NOM-127-SSA1-1994. Los resultados mostraron valores bajos en la concentración de metales pesados en agua para riego agrícola y uso urbano, no así, para el criterio de consumo humano, pues 50 % de las muestras tomadas presentaron concentraciones por encima de los límites permisibles para Cd, 20 % para Hg y 2 % para Pb (SSA 2000). Se concluyó que el agua superficial no representa riesgos para riego agrícola. La mayor concentración y dispersión la presentó el As con valores de 0.0 a 0.78 mg L-1, mientras que la menor con 0.0 a 0.03 mg L-1, fue para el Hg. Las descargas de agua residual hacia los ríos, contaminan gravemente y llevan a sobrepasar los límites permisibles para Cd, Hg y Pb en agua para uso y consumo humano.
A microsatellite study of bovine solute carrier family 11 a1 (Slc11a1) gene diversity in Mexico in relation to bovine tuberculosis
Vázquez-Flores, Felicitas;Alonso, Rogelio;Villegas-Sepúlveda, Nicolás;Arriaga, Camila;Pereira-Suárez, Ana Laura;Mancilla, Raúl;Estrada-Chávez, Ciro;
Genetics and Molecular Biology , 2006, DOI: 10.1590/S1415-47572006000300019
Abstract: bovine tuberculosis, caused by mycobacterium bovis, is a disease of socio-economic and public health importance and of significance to international trade regulation. allelic variants of several genes have been implicated in the genetic susceptibility to tuberculosis in some human populations, but little is known in cattle. we surveyed 34 european, 18 asian, 20 creole and 23 hybrid bovines for polymorphisms of the bovine solute carrier family 11 a1(slc11a1) gene, formerly known as natural resistance associated macrophage protein (nramp1), gene by typing the cattle using two microsatellite loci closely linked to this gene. the microsatellites used were 311-22, located at the 3' untranslated region (3' utr) of the slc11a1 gene, and aro28 situated about 0.6 cm upstream of the same gene based on allele size in base pairs (bp) we determined five 311-223 locus variants (221, 223, 225, 227 and 229 bp) and 12 aro28 loci. there was marked diversity and a very high level of heterozygosity in most of the cattle surveyed except the europeans bovines and especially holsteins in relation to the 3' utr microsatellite locus.
Algunas consideraciones teóricas de la asistencia social alimentaria y de la evaluación de programas
Mancilla López,Lorena Patricia;
Perspectivas en Nutrición Humana , 2010,
Abstract: around world there is a 1.020 million of people suffering chronic hunger or undernourished, of which 1002 million are currently living in developing countries. as a result of nutritional insecurity, people living this situation could present low academic performance, learning difficulties, growth retardation and malnutrition; they have severe morbidity, high mortality and greater vulnerability to natural disasters, all these factors can be finally translated to poverty. in order to address these consequences, food assistance programs are developed in programs to struggle poverty; these programs have been widespread in latin america. in colombia food assistance programs emerge under the concept of social risk management and its actions are lead by the social protection system. regardless of the experience of these institutions developing, following and evaluating the programs; there is still necessary to improve these facts in order to establish public policies based on scientific evidence.
Moore-Penrose Inverse and Semilinear Equations  [PDF]
Hugo Leiva, Raúl Manzanilla
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2018, DOI: 10.4236/alamt.2018.81002
Abstract: In this paper, we study the existence of solutions for the semilinear equation \"\", where A is a \"\", \"\", \"\" and \"\" is a nonlinear continuous function. Assuming that the Moore-Penrose inverse AT(AAT)-1?exists (A denotes the transposed matrix of A) which is true whenever the determinant of the \"\" matrix AAT is different than zero, and the following condition on the nonlinear term \"\" satisfied \"\". We prove that the semilinear equation has solutions for all\"\". Moreover, these solutions can be found from the following fixed point relation \"\".
Stability analysis of a certain class of time-varying hybrid dynamical systems
Mancilla Aguilar,J. L.; García,R. A.;
Latin American applied research , 2003,
Abstract: in this work we study the exponential stability of a class of hybrid dynamical systems that comprises the sampled-data systems consisting of the interconnection of a time-varying nonlinear continuous-time plant and a time-varying nonlinear discrete-time controller, assuming that the sampling periods are not necessarily constant. for this purpose we develop an indirect lyapunov method of analysis, and show that under adequate hypotheses the exponential stability of the hybrid dynamical system is equivalent to the exponential stability of its linearization.
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