Elaboración del plan de implementación de la metodología toc en una empresa procesadora de productos de acero”

Uno de los grandes problemas de la industria ecuatoriana es el incumplimiento en las promesas de entrega o en el caso de las comercializadoras no poseer el producto que el cliente requiere en el momento adecuado; todo esto conlleva a la pérdida de ventas, o lo que es peor, la pérdida de clientes potenciales; ACEROS S.A. no es ajena a los problemas que presenta la industria y como toda empresa cuyo deseo es crecer día tras día, se encuentra en la búsqueda de un sistema que permita administrar las operaciones desde un punto de vista global. El presente proyecto se basó en el trabajo del Dr. Eliyahu. M. Goldratt sobre la Teoría de Restricciones (TOC) como una metodología para mejorar continuamente a la organización y convertirla en siempre próspera. Debido a que TOC ha sido poco aplicada en el país e implica grandes cambios en las políticas de trabajo establecidas, la compañía ACEROS S.A. deseaba tener conocimiento de cuál es la manera adecuada de implementar esta metodología de trabajo; al mismo tiempo que deseaba conocer los potenciales beneficios que se obtendrían si se cambia la manera de llevar a cabo las operaciones. A lo largo de este trabajo se presentan los conceptos principales sobre TOC, se realizó un diagnóstico de la situación actual de la compañía y se definió la estrategia o grupo de estrategias TOC que mejor se adaptan a la realidad de la compañía. Una vez elegido el grupo de estrategias a aplicar, se presenta a manera de procedimiento el plan que deberá seguir la empresa para implementar correctamente una estrategia basada en teoría de restricciones. Para esto se hizo uso de los árboles de estrategia y tácticas que han sido desarrollados por el Dr. Goldratt. El plan de implementación que se presenta en este trabajo permitirá a la compañía alinear su cadena de suministros y brindará un mecanismo para ofrecer plazos de entrega confiables al mismo tiempo que establecerá las bases para futuros planes de mejora continua. Finalmente se realizó una estimación de las mejoras tanto financieras como operacionales a obtenerse como resultado de la implementación del plan en la compañía, entre las cuales se tienen: cumplimiento en las fechas de entrega en un porcentaje superior al 98%, disponibilidad de productos superior al 90%, disminución de los niveles de inventarios y aumento en rentabilidad; sin que esto implique tomar decisiones que puedan poner en riesgo a la compañía.

APL: Un Lenguaje de Programación basado en Audio para Aprendices Ciegos

Expanded the number of users who can program or learn how to program. They are focused on sighted users. This study introduces APL, an Audio Programming Language for blind learners. APL is a programming language with audio-based interfaces to assist blind learners to develop problem solving and algorithmic thinking skills. APL is also a way to help blind learners to construct meaning by making programs. APL is a programming language by and for blind learners. We tested APL with novice blind programmers during and after development. They tried, analyzed and make improvements to APL. They usability tested APL by solving problems with increasingly complexity and answering usability questionnaires. Blind users understood APL, made programs, mapped the programming process and enjoyed the experience showing that a programming language based on audio can be constructed to fit the needs and mental models of blind learners to help them to enter to the programming world.El desarrollo de habilidades de programación es un tema relevante en las ciencias de la computación. Los lenguajes de programación han sido usados progresivamente para satisfacer las necesidades y ensamblar con los modelos mentales de los usuarios finales. En el último tiempo se ha expandido el número de usuarios que pueden programar o aprender a programar. La mayoría de estos lenguajes se centran en usuarios videntes. Este estudio introduce APL, lenguaje de programación a través de audio para aprendices ciegos. APL es un lenguaje de programación basado en interfaces de audio para asistir a aprendices ciegos en el desarrollo de habilidades de resolución de problemas y pensamiento algorítmico. APL es también una forma de ayudar a aprendices ciegos a construir significado escribiendo programas computacionales. APL es un lenguaje de programación diseñado por y para aprendices ciegos. APL fue evaluado con aprendices de programación novatos durante y después de su implementación. Ellos conocieron el lenguaje, lo analizaron y realizaron sugerencias para su mejoramiento. La usabilidad de APL fue evaluada por los aprendices a través de la resolución de problemas de complejidad creciente y la aplicación de cuestionarios de usabilidad. Como resultado, los aprendices ciegos escribieron programas, entendieron el proceso de programación y disfrutaron la experiencia. Nuestros resultados preliminares evidencian que es posible construir un lenguaje de programación basado en audio que ensamble con las necesidades y los modelos mentales de aprendices ciegos para ayudarlos a ingresar al mundo de la programación y desarrollar habilidades de resolución de problemas

Genetic diversity and origins of the homoploid type hybrid Phytophthora×alni

Assessing the process that gives rise to hybrid pathogens is central to understanding the evolution of emerging plant diseases. Phytophthora xalni, a pathogen of alder, results from the homoploid hybridization of two related species, Phytophthora uniformis and Phytophthora xmultiformis. Describing the genetic characteristics of P. xalni should help us understand how reproductive mechanisms and historical processes shaped the population structure of this emerging hybrid pathogen. The population genetic structure of P. xalni and the relationship with its parental species were investigated using 12 microsatellites and one mitochondrial DNA (mtDNA) marker on a European collection of 379 isolates. Populations of P. xalni were dominated by one multilocus genotype (MLG). The frequency of this dominant MLG increased after the disease emergence together with a decline in diversity, suggesting that it was favored by a genetic mechanism such as drift or selection. Combined microsatellite and mtDNA results confirmed that P. xalni originated from multiple hybridization events that involved different genotypes of the progenitors. Our detailed analyses point to a geographic structure that mirrors that observed for P. uniformis in Europe. The study provides more insights on the contribution of P. uniformis, an invasive species in Europe, to the emergence of Phytophthora-induced alder decline. IMPORTANCE Our study describes an original approach to assess the population genetics of polyploid organisms using microsatellite markers. By studying the parental subgenomes present in the interspecific hybrid P. xalni, we were able to assess the geographical and temporal structure of European populations of the hybrid, shedding new light on the evolution of an emerging plant pathogen. In turn, the study of the parental subgenomes permitted us to assess some genetic characteristics of the parental species of P. xalni, P. uniformis, and P. xmultiformis, which are seldom sampled in nature. The subgenomes found in P. xalni represent a picture of the "fossilized" diversity of the parental species

Hipoacusia neurosensorial, ataxia cerebelosa y piramidalismo: una tríada sugerente de siderosis superficial del sistema nervioso central

Superficial siderosis of the central nervous system is an underdiagnosed pathology. It is most likely produced because of persistent bleeding that causes hemosiderin deposition in the nervous structures. This generates oxidative damage in the glial tissue, which causes progressive central nervous system dysfunction. Symptoms depend on the affected areas. The diagnosis and characterization of superficial siderosis are mainly carried out by brain and spinal cord magnetic resonance imaging. In most cases its approach is surgical, although without providing significant benefit. Nowadays, no efficient treatment is available to stop the evolution of the disease.La siderosis superficial del sistema nervioso central es una patología infradiagnosticada. Muy probablemente, se produce por un sangrado persistente que provoca el depósito de hemosiderina en las estructuras nerviosas. Esto genera daño oxidativo a nivel glial, provocando la disfunción progresiva del sistema nervioso central. Sus formas de manifestación dependen de las áreas afectadas. El diagnóstico y la caracterización de la siderosis superficial se llevan a cabo, principalmente, mediante resonancia magnética cerebral y de médula espinal. Su abordaje es, en la mayoría de los casos, quirúrgico, sin que aporte un beneficio significativo. En la actualidad, no se dispone de un tratamiento que consiga modificar de forma eficaz el curso natural de la enfermedad

Genotypic diversity of Acanthamoeba strains isolated from Chilean patients with Acanthamoeba keratitis

Acanthamoeba spp. are the causative agents of a severe keratitis occurring mainly in contact lens wearers. The genus comprises more than 24 species that are currently divided into 20 different genotypes (T1-T20) according to sequence variations in the 18S rRNA gene. The objective of this study was to identify the genotypes and sub-genotypes of Acanthamoeba isolates collected at the Parasitology Laboratory of the Public Health Institute of Chile, the only laboratory in the country where Acanthamoeba screening is performed. This is the first report of genotypic identification of clinical isolates of Acanthamoeba in Chile and one of the few in South America. T2, T4 and T11 genotypes were predominantly isolated from the Acanthamoeba keratitis patients in Chile. Chilean predominant T4 sub-genotypes, which have also been reported worldwide, formed a separate cluster of the minority T4 variants. This study provides useful information about the predominant genotypes and subgenotypes that would be useful in selecting suitable strains to develop immunological and/or molecular diagnostic assays in Chile

Determination of differences in anatomical and chemical characteristics of tension and opposite wood of 8-year old Eucalyptus globulus

La madera de tensión y opuesta, dividida en las correspondientes regiones de albura y duramen, de árboles de 8 años de Eucalyptus globulus fueron caracterizadas con respecto a su composición química y anatomía de la fibra (en la sección tranversal) de manera de identificar las principales diferencias. Paredes celulares gruesas y poco lignificadas fueron encontradas en la madera de tensión. El contenido de celulosa fue similar en ambos tipos de madera, sin embargo, la madera de tensión contiene 30% más xilosa y 15% menos lignina que la madera opuesta. La lignina de la madera de tensión contiene 24% más unidades siringilo y una alta frecuencia de enlaces β-O-4. El análisis de componentes principales (PCA) realizado separadamente para los datos anatómicos y químicos mostró una clara separación entre la madera de tensión y opuesta. Las principales características utilizadas para la separación fueron el espesor de pared celular, diámetro de vasos, diámetro de lumen, contenidos de lignina y xilosa, y contenido de unidades siringilo. AbstractTension and opposite wood, divided in the corresponding heartwood and sapwood regions, from 8-year old Eucalyptus globulus trees were characterized for chemical composition and fibre anatomy in the transverse section in order to identify the main differences. Thicker and poorly lignified cell walls were found in tension wood. Cellulose content was similar for both woods, although tension wood contained 30% higher xylose and 15% less lignin than opposite wood. Lignin of tension wood contained 24% more syringyl units and a higher frequency of β-O-4 linkages. Principal component analysis (PCA) performed separately with anatomical and chemical data showed a clear separation between tension and opposite wood. The principal characteristics used for separation were: cell wall thickness, vessel diameter, lumen diameter, lignin and xylose content, and amount of syringyl units

Genes associated with metabolic syndrome predict disease-free survival in stage II colorectal cancer patients. A novel link between metabolic dysregulation and colorectal cancer

Producción CientíficaStudies have recently suggested that metabolic syndrome and its components increase the risk of colorectal cancer. Both diseases are increasing in most countries, and the genetic association between them has not been fully elucidated. The objective of this study was to assess the association between genetic risk factors of metabolic syndrome or related conditions (obesity, hyperlipidaemia, diabetes mellitus type 2) and clinical outcome in stage II colorectal cancer patients. Expression levels of several genes related to metabolic syndrome and associated alterations were analysed by real-time qPCR in two equivalent but independent sets of stage II colorectal cancer patients. Using logistic regression models and cross-validation analysis with all tumour samples, we developed a metabolic syndrome-related gene expression profile to predict clinical outcome in stage II colorectal cancer patients. The results showed that a gene expression profile constituted by genes previously related to metabolic syndrome was significantly associated with clinical outcome of stage II colorectal cancer patients. This metabolic profile was able to identify patients with a low risk and high risk of relapse. Its predictive value was validated using an independent set of stage II colorectal cancer patients. The identification of a set of genes related to metabolic syndrome that predict survival in intermediate-stage colorectal cancer patients allows delineation of a high-risk group that may benefit from adjuvant therapy and avoid the toxic and unnecessary chemotherapy in patients classified as low risk. Our results also confirm the linkage between.Ministerio de Ciencia, Innovación y Universidades (AGL2010-21565, RyC 2008-03734, IPT-2011-1248-060000),y la Comunidad de Madrid (ALIBIRD, S2009/AGR-1469

KRAS Mutations in Primary Colorectal Cancer Tumors and Related Metastases: A Potential Role in Prediction of Lung Metastasis

BACKGROUND:KRAS mutations in colorectal cancer primary tumors predict resistance to anti-Epidermal Growth Factor Receptor (EGFR) monoclonal antibody therapy in patients with metastatic colorectal cancer, and thus represent a true indicator of EGFR pathway activation status. METHODOLOGY/PRINCIPAL FINDINGS:KRAS mutations were retrospectively studied using polymerase chain reactions and subsequent sequencing of codons 12 and 13 (exon 2) in 110 patients with metastatic colorectal tumors. These studies were performed using tissue samples from both the primary tumor and their related metastases (93 liver, 84%; 17 lung, 16%). All patients received adjuvant 5-Fluorouracil-based polychemotherapy after resection of metastases. None received anti-EGFR therapy. Mutations in KRAS were observed in 37 (34%) of primary tumors and in 40 (36%) of related metastases, yielding a 94% level of concordance (kappa index 0.86). Patients with primary tumors possessing KRAS mutations had a shorter disease-free survival period after metastasis resection (12.0 vs 18.0 months; P = 0.035) than those who did not. A higher percentage of KRAS mutations was detected in primary tumors of patiens with lung metastases than in patients with liver metastases (59% vs 32%; p = 0.054). To further evaluate this finding we analyzed 120 additional patients with unresectable metastatic colorectal cancer who previously had their primary tumors evaluated for KRAS mutational status for clinical purposes. Separately, the analysis of these 120 patients showed a tendency towards a higher degree of KRAS mutations in primary tumors of patients with lung metastases, although it did not reach statistical significance. Taken together the group of 230 patients showed that KRAS was mutated significantly more often in the primary tumors of patients with lung metastases (57% vs 35%; P = 0.006). CONCLUSIONS/SIGNIFICANCE:Our results suggest a role for KRAS mutations in the propensity of primary colorectal tumors to metastasize to the lung