Performance of an ablator for Space Shuttle inorbit repair in an arc-plasma airstream

An ablator patch material performed well in an arc plasma environment simulating nominal Earth entry conditions for the Space Shuttle. Ablation tests using vacuum molded cones provided data to optimize the formulation of a two part polymer system for application under space conditions. The blunt cones were made using a Teflon mold and a state of the art caulking gun. Char stability of formulations with various amounts of catalyst and diluent were investigated. The char was found to be unstable in formulations with low amounts of catalyst and high amounts of diluent. The best polymer system determined by these tests was evaluated using a half tile patch in a multiple High Temperature Reusable surface Insulation tile model. It was demonstrated that this ablator could be applied in a space environment using a state of the art caulking gun, would maintain the outer mold line of the thermal protection system during entry, and would keep the bond line temperature at the aluminum tile interface below the design limit

Designing a management model for the proper handling of complaints and claims in the department of customer service

El presente artículo tiene como propósito desarrollar y diseñar un diagrama de flujo para la planeación y operación al proceso de reclamaciones en el departamento de servicio al cliente de una compañía ya que uno de los problemas principales dentro de una organización es el adecuado proceso de recepción y cierre de quejas y reclamos además de no contar con el control y seguimiento de la operación, lo anterior busca desarrollar un modelo de mejoramiento en el proceso con el fin de proponer alternativas optimas y un sistema eficiente que refleje ventajas competitivas frente a los competidores, fidelización de clientes y mayor posicionamiento en el mercadoThis article aims to develop and design a flowchart for the planning and operation to process claims in the department of customer service from a company as one of the major problems within an organization is the right process of receiving and closure of complaints besides not having the control and monitoring of the operation, the above seeks to develop a model of improvement in the process in order to propose optimum alternatives and an efficient system that reflects competitive advantages over competitors, loyalty customers and greater market positionin

Vegetation density as deduced from ERTS-1 MSS response

Reflectance from vegetation increases with increasing vegetation density in the 0.75- to 1.35 micron wavelength interval. Therefore, ERTS-1 bands 6 (0.7 to 0.8 micron) and 7 (0.8 to 1.1 micron) contain information that should relate to the probable yield of crops and the animal carrying capacity of rangeland. The results of an experiment designed specifically to test the relations among leaf area index (LAI), plant population, plant cover and plant height, and the ERTS-1 MSS responses for 3 corn, 10 sorghum, and 10 cotton fields are given. Plant population was as useful as LAI for characterizing the sorghum and corn fields, and plant height was as good as LAI for characterizing cotton fields. These findings generally support the utility of ERTS-1 data for explaining variability in green biomass, harvestable forage and other indicators of productivity

Biopesticide activity from drimanic compounds to control tomato pathogens

Indexación: Scopus.Tomato crops can be affected by several infectious diseases produced by bacteria, fungi, and oomycetes. Four phytopathogens are of special concern because of the major economic losses they generate worldwide in tomato production; Clavibacter michiganensis subsp. michiganensis and Pseudomonas syringae pv. tomato, causative agents behind two highly destructive diseases, bacterial canker and bacterial speck, respectively; fungus Fusarium oxysporum f. sp. lycopersici that causes Fusarium Wilt, which strongly affects tomato crops; and finally, Phytophthora spp., which affect both potato and tomato crops. Polygodial (1), drimenol (2), isonordrimenone (3), and nordrimenone (4) were studied against these four phytopathogenic microorganisms. Among them, compound 1, obtained from Drimys winteri Forst, and synthetic compound 4 are shown here to have potent activity. Most promisingly, the results showed that compounds 1 and 4 affect Clavibacter michiganensis growth at minimal inhibitory concentrations (MIC) values of 16 and 32 μg/mL, respectively, and high antimycotic activity against Fusarium oxysporum and Phytophthora spp. with MIC of 64 μg/mL. The results of the present study suggest novel treatment alternatives with drimane compounds against bacterial and fungal plant pathogens. © 2018 by the authors.https://www.mdpi.com/1420-3049/23/8/205

Externalizing behavior in African American youth from single mother homes: the relative role of parents and peers

Parents and peers have been identified as important contexts in which to study youth externalizing behavior. African American youth, particularly those from single mother homes, are overrepresented in statistics on aggression and delinquency; yet, relatively few studies have examined the relative influence of both parents and peers on externalizing behavior in this at-risk group. The current study examines the contributions of both positive parenting and peer relationships to externalizing behavior in a sample of African American youth from single mother homes (n = 184). Main effects were found for positive parenting and peer deviant behavior, but not for peer relationship quality. The proposed 2- and 3-way interactions were not significant. Peer deviant behavior and peer relationship quality partially mediated the association between positive parenting and youth externalizing behavior. Findings will inform a more theoretically rich contextual model for better understanding of externalizing behavior in African American youth from single mother homes

Plasma miRNAs as biomarkers for endometriosis

STUDY QUESTION: Can plasma miRNAs be used for the non-invasive diagnosis of endometriosis in infertile women? SUMMARY ANSWER: miRNA-based diagnostic models for endometriosis failed the test of independent validation. WHAT IS KNOWN ALREADY: Circulating miRNAs have been described to be differentially expressed in patients with endometriosis compared with women without endometriosis, suggesting that they could be used for the non-invasive diagnosis of endometriosis. However, these studies have shown limited consistency or conflicting results, and no miRNA-based diagnostic test has been validated in an independent patient cohort. STUDY DESIGN, SIZE, DURATION: We performed genome-wide miRNA expression profiling by small RNA sequencing to identify a set of plasma miRNAs with discriminative potential between patients with and without endometriosis. Expression of this set of miRNAs was confirmed by RT-qPCR. Diagnostic models were built using multivariate logistic regression with stepwise feature selection. In a final step, the models were tested for validation in an independent patient cohort. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Plasma of all patients was available in the biobank of the Leuven Endometriosis Centre of Excellence. Biomarker discovery and model development were performed in a discovery cohort of 120 patients (controls= 38, endometriosis= 82), and models were tested for validation in an independent cohort of 90 patients (controls= 30, endometriosis= 60). RNA was extracted with the miRNeasy Plasma Kit. Genome-wide miRNA expression analysis was done by small RNA sequencing using the NEBNext small RNA library prep kit and the NextSeq 500 System. cDNA synthesis and qPCR were performed using the Qiagen miScript technology. MAIN RESULTS AND THE ROLE OF CHANCE: We identified a set of 42 miRNAs with discriminative power between patients with and without endometriosis based on genome-wide miRNA expression profiling. Expression of 41 miRNAs was confirmed by RT-qPCR, and 3 diagnostic models were built. Only the model for minimal-mild endometriosis (Model 2: hsa-miR-125b-5p, hsa-miR-28-5p and hsa-miR-29a-3p) had diagnostic power above chance performance in the independent validation (AUC= 60%) with an acceptable sensitivity (78%) but poor specificity (37%). LIMITATIONS, REASONS FOR CAUTION: The diagnostic models were built and tested for validation in two patient cohorts from a single tertiary endometriosis centre. Further validation tests in large cohorts with patients from multiple endometriosis centres are needed. WIDER IMPLICATION OF THE FINDINGS: Our study supports a possible biological link between certain miRNAs and endometriosis, but the potential of these miRNAs as clinically useful biomarkers is questionable in women with infertility. Large studies in well-described patient cohorts, with rigorous methodology for miRNA expression analysis, sufficient statistical power and an independent validation step, are necessary to answer the question of whether miRNAs can be used as diagnostics markers for endometriosis

The total synthesis of alternaric acid and progress toward the synthesis of subglutinol

The Oshima-Utimoto reaction coupling an allylic alcohol and butyl vinyl ether is utilized to construct the furan ring of the natural product subglutinol B. Methodology for the diastereoselective substitution of furans is also reported. Methodology utilizing silylglyoxylates as latent acyl anions for use in stereoselective multicomponent reactions is developed in the form of addition of carbon nucleophiles followed by an intermolecular aldol reaction. This methodology was then applied towards the total synthesis of alternaric acid

Estrategias pedag?gicas para el fortalecimiento de competencias ciudadanas, desde el est?ndar: La pluraidad, identidad y valoraci?n de las diferencias

240 p. Recurso Electr?nicoEn Colombia, la formaci?n ciudadana es un reto que debe asumir la escuela, pues es el espacio propicio para la convivencia, para la construcci?n y aplicaci?n de normas, para ense?ar y aprender valores; para aprender a participar y conocer las formas adecuadas de hacerlo. Este proceso debe ser llevado a cabo de manera consciente, planeado, a partir del contexto, de las necesidades y expectativas de los educandos. Escena donde los docentes se hacen imprescindibles, pues en ?ltimas, es en quienes recae tal responsabilidad. Atendiendo a lo anterior, el trabajo se propone plantear estrategias pedag?gicas que permitan el fortalecimiento de las competencias ciudadanas desde el est?ndar: La pluralidad, identidad, y valoraci?n de las diferencias, en estudiantes del grado noveno de la Instituci?n Educativa Guillermo Angulo G?mez, de la ciudad de Ibagu?. Con el fin de cumplir el objetivo, la investigaci?n se enmarca dentro del construccionismo social y se desarrolla a partir del enfoque cualitativo. Como estrategia de indagaci?n, el trabajo se orienta desde el estudio descriptivo; se emplea como recurso para obtener la informaci?n, las entrevistas semi-estructuradas individuales ?aplicadas a los docentes- y a dos grupos focales ?conformados por diez estudiantes-. El tratamiento de la informaci?n, se da a partir de la teor?a fundamentada, a trav?s de la cual se logra mayor riqueza y profundidad en el an?lisis. En este orden de ideas, la propuesta gira en torno al aprovechamiento de los recursos con que cuenta la instituci?n; al talento de docentes y l?deres estudiantiles, quienes a partir de la apropiaci?n de sus roles, podr?n desarrollar estrategias pedag?gicas que permitan a los j?venes respetar y valorar no solo sus ideas, tambi?n las de los dem?s, capaces de proponer alternativas de soluci?n para los conflictos que como humanos se deben superar a trav?s del di?logo, j?venes que contribuyan en la construcci?n de un pa?s, seg?n sus necesidades, su identidad, su diversidad. Palabras claves: Competencia, multiculturalismo, ciudadano, estrategia pedag?gica.In Colombia, civic education is a challenge that the school must take on, since it is the propitious space for coexistence, for the construction and application of norms, for teaching and learning values; to learn to participate and know the proper ways to do it. This process must be carried out consciously, planned, from the context, the needs and expectations of the students. Scenario where teachers are essential, because at the end, they are the ones who are responsible. In view of the previous idea, the work proposes to set pedagogical strategies that allow the strengthening of citizen competencies from the standard: Plurality, identity, and assessment of differences, in ninth grade students of the Guillermo Angulo G?mez Educational Institution, of the city of Ibagu?. In order to fulfill the objective, the research is framed within social constructionism and is developed from the qualitative approach; As a strategy of inquiry, the work is oriented from the descriptive study; it is used as a resource to obtain the information, semi-structured individual interviews - applied to teachers - and to two focal groups - made up of ten students -; the treatment of information is based on grounded theory, through which greater richness and depth in the analysis is achieved. In this order of ideas, the proposal takes place around the use of the resources available to the institution; the talent of teachers and student leaders, who from the appropriation of their roles, can develop pedagogical strategies that allow young people to respect and value not only their ideas, but also those of others, capable of proposing alternative solutions for conflicts that as human beings they must be overcome through dialogue, young people who contribute in the construction of a country, according to their needs, their identity, their diversity. Keywords: Competence, multiculturalism, citizen, pedagogical strategy