Metodología para selección tribológica de lubricantes para formado de cuerpos de aluminio

Los refrigerantes para el “formado de cuerpo” de latas de aluminio consisten de emulsiones de aceite en agua los cuales son utilizados como lubricantes en el proceso de planchado. Estos lubricantes se formulan para enfriar la interfase en el proceso de formación de la lata y proveer la lubricidad necesaria para el planchado. En el presente trabajo se presenta una nueva metodología para la selección de distintos refrigerantes para “formado de cuerpo” en función a su desempeño tribológico utilizando un tribómetro de confi guración espiga y bloque en V. Los resultados experimentales indican que la conductividad térmica de cada lubricante es un parámetro muy importante en su desempeño tribológico. Este método se aplica ya con éxito para evaluar y comparar el funcionamiento de refrigerantes comerciales para “formado de cuerpo” de latas de aluminio

Confidence-Based Learning in Investment Analysis

The aim of this study is to determine the effectiveness of using multiple choice tests in subjects related to the administration and business management. To this end we used a multiple-choice test with specific questions to verify the extent of knowledge gained and the confidence and trust in the answers. The tests were performed in a group of 200 students at the bachelor's degree in Business Administration and Management. The analysis made have been implemented in one subject of the scope of investment analysis and measured the level of knowledge gained and the degree of trust and security in the responses at two different times of the course. The measurements have been taken into account different levels of difficulty in the questions asked and the time spent by students to complete the test. The results confirm that students are generally able to obtain more knowledge along the way and get increases in the degree of trust and confidence in the answers. It is confirmed as the difficulty level of the questions set a priori by the heads of the subjects are related to levels of security and confidence in the answers. It is estimated that the improvement in the skills learned is viewed favourably by businesses and are especially important for job placement of students

La organización de las mujeres en el Sindicato Nacional de Trabajadores de Agricultura y Recursos Hidráulicos (SNTAR)

Las luchas sindicales que han emprendido las trabajadoras de la SARH han sido, principalmente, de las madres y en momentos coyuntrales, con excepción de un movimiento fuerte que hubo en 1984 en Jalapa, Veracruz, donde las mujeres de esa sección se destacaron por su participación en todos los niveles para democratizar su sindicato. El CEN, conjuntamente con las autoridades estatales, reprimieron su movimiento y varas trabajadoras fueron despedidas y otras reubicada

Estrategias de política económica dirigidas al sector ganadero. 2010-2015

El objetivo del escrito es analizar los impactos sectoriales de las estrategias de política económica dirigidas al sector ganadero de Nicaragua. Así pues, para efectos de desarrollo del estudio investigativo se ha recurrido al método de análisis-síntesis que ha permitido observar, comprender, explicar y valorar las estrategias de política implementadas en el sector pecuario de Nicaragua entre 2010 y 2015. De ahí que se induzca que tales ordenanzas han logrado cumplir en gran medida los objetivos de crecimiento del sector e incremento de su productividad. No obstante, deben redirigirse acciones para dinamizar ciertas actividades pertenecientes al sector como la porcina, a la cual no se destinan recursos suficientes para su desarrollo. Paralelamente, cabe destacar el elevado potencial que representa este sector para contribuir a los Objetivos de Desarrollo Sostenible (ODS), por su incidencia en los sistemas alimentarios, económicos y ambientales; sin embargo, éste está siendo subutilizado. Por ello, se propone intervenir en los desafíos de la producción pecuaria e identificar nuevas herramientas y mejores políticas para el desarrollo de la ganadería sostenible en el territorio

Cisplatin-induced ototoxicity: effects, mechanisms and protection strategies

Cisplatin is a highly effective chemotherapeutic agent that is widely used to treat solid organ malignancies. However, serious side effects have been associated with its use, such as bilateral, progressive, irreversible, dose-dependent neurosensory hearing loss. Current evidence indicates that cisplatin triggers the production of reactive oxygen species in target tissues in the inner ear. A variety of agents that protect against cisplatin-induced ototoxicity have been successfully tested in cell culture and animal models. However, many of them interfere with the therapeutic effect of cisplatin, and therefore are not suitable for systemic administration in clinical practice. Consequently, local administration strategies, namely intratympanic adminis- tration, have been developed to achieve otoprotection, without reducing the antitumoral effect of cisplatin. While a considerable amount of pre-clinical information is available, clinical data on treatments to prevent cisplatin ototoxicity are only just beginning to appear. This review summarizes clinical and experimental studies of cisplatin ototoxicity, and focuses on understanding its toxicity mechanisms, clinical repercussions and prevention strategies

"INTERGROWTH21st vs customized fetal growth curves in the assessment of the neonatal nutritional status: a retrospective cohort study of gestational diabetes"

Background Gestational diabetes mellitus is associated with increased incidence of adverse perinatal outcomes including newborns large for gestational age, macrosomia, preeclampsia, polyhydramnios, stillbirth, and neonatal morbidity. Thus, fetal growth should be monitored by ultrasound to assess for fetal overnutrition, and thereby, its clinical consequence, macrosomia. However, it is not clear which reference curve to use to define the limits of normality. Our aim is to determine which method, INTERGROWTH21st or customized curves, better identifies the nutritional status of newborns of diabetic mothers. Methods This retrospective cohort study compared the risk of malnutrition in SGA newborns and the risk of overnutrition in LGA newborns using INTERGROWTH21st and customized birth weight references in gestational diabetes. The nutritional status of newborns was assessed using the ponderal index. Additionally, to determine the ability of both methods in the identification of neonatal malnutrition and overnutrition, we calculate sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratios. Results Two hundred thirty-one pregnant women with GDM were included in the study. The rate of SGA indentified by INTERGROWTH21st was 4.7% vs 10.7% identified by the customized curves. The rate of LGA identified by INTERGROWTH21st was 25.6% vs 13.2% identified by the customized method. Newborns identified as SGA by the customized method showed a higher risk of malnutrition than those identified as SGA by INTERGROWTH21st. (RR 4.24 vs 2.5). LGA newborns according to the customized method also showed a higher risk of overnutrition than those classified as LGA according to INTERGROWTH21st. (RR 5.26 vs 3.57). In addition, the positive predictive value of the customized method was superior to that of INTERGROWTH21st in the identification of malnutrition (32% vs 27.27%), severe malnutrition (22.73% vs 20%), overnutrition (51.61% vs 32.20%) and severe overnutrition (28.57% vs 14.89%). Conclusions In pregnant women with DMG, the ability of customized fetal growth curves to identify newborns with alterations in nutritional status appears to exceed that of INTERGROWTH21s

Actividad EEG durante dos tipos de estimulación sensitiva. A propósito de un caso.

[Objetivo] Entender mejor los fenómenos neurofisiológicos que acontecen a nivel cortical en el sujeto sano ante la exploración rutinaria de la sensibilidad.Peer reviewe

Distilling a visual network of Retinitis Pigmentosa gene-protein interactions to uncover new disease candidates

BACKGROUND: Retinitis pigmentosa (RP) is a highly heterogeneous genetic visual disorder with more than 70 known causative genes, some of them shared with other non-syndromic retinal dystrophies (e.g. Leber congenital amaurosis, LCA). The identification of RP genes has increased steadily during the last decade, and the 30% of the cases that still remain unassigned will soon decrease after the advent of exome/genome sequencing. A considerable amount of genetic and functional data on single RD genes and mutations has been gathered, but a comprehensive view of the RP genes and their interacting partners is still very fragmentary. This is the main gap that needs to be filled in order to understand how mutations relate to progressive blinding disorders and devise effective therapies. METHODOLOGY: We have built an RP-specific network (RPGeNet) by merging data from different sources: high-throughput data from BioGRID and STRING databases, manually curated data for interactions retrieved from iHOP, as well as interactions filtered out by syntactical parsing from up-to-date abstracts and full-text papers related to the RP research field. The paths emerging when known RP genes were used as baits over the whole interactome have been analysed, and the minimal number of connections among the RP genes and their close neighbors were distilled in order to simplify the search space. CONCLUSIONS: In contrast to the analysis of single isolated genes, finding the networks linking disease genes renders powerful etiopathological insights. We here provide an interactive interface, RPGeNet, for the molecular biologist to explore the network centered on the non-syndromic and syndromic RP and LCA causative genes. By integrating tissue-specific expression levels and phenotypic data on top of that network, a more comprehensive biological view will highlight key molecular players of retinal degeneration and unveil new RP disease candidates

Cuadernos para el docente

Horizontes representa una propuesta pedagógica que incluye programas de televisión para las áreas de Lengua, Matemática, Ciencias Sociales y Ciencias Naturales. Su intención es acompañar las actividades de la Escuela Secundaria Rural y difundir contenidos audiovisuales articulados con las unidades didácticas desarrolladas a lo largo de los CUADERNOS DE ESTUDIO de las áreas disciplinares mencionadas