1,041 research outputs found

    Characterising epithelial tissues using persistent entropy

    Full text link
    In this paper, we apply persistent entropy, a novel topological statistic, for characterization of images of epithelial tissues. We have found out that persistent entropy is able to summarize topological and geometric information encoded by \alpha-complexes and persistent homology. After using some statistical tests, we can guarantee the existence of significant differences in the studied tissues.Comment: 12 pages, 7 figures, 4 table

    Emulsifier and antioxidant properties of by-products obtained by enzymatic degumming of soybean oil

    Get PDF
    The enzymes used in degumming, called phospholipases, specifically act on phospholipids without degrading the oil itself. Degumming using a phospholipase C enzyme allows to meet all market specifications while it increases the oil yield. The aim of this study was to evaluate antioxidant and emulsifier properties of the recovered gum (RG) obtained by enzymatic oil degumming process of crude soybean oil subjected to modifications as deoiling (RG deoiled) or ethanol fractionation (RG soluble and insoluble). RG soluble allowed obtaining more stable O/W emulsions (30:70 w/w) in comparison with those by-products assayed at different concentrations (0.1?1.0%). Also, deoiled soybean lecithin (DSL) andRG deoiled had a similar behavior in relation to the kinetic destabilization (%BS profiles), despite the different degumming processes used to obtain these samples. The study on induction times (Metrohm Rancimat) showed a significant antioxidant effect (p<0.05) against a refined sunflower oil associated with all the by-products analyzed. However, RG soluble and DSL showed a strong effect on the oil stability at high concentrations (1000?2000 ppm). These results showed that the deoiled recovered gum and its derivates obtained by ethanol fractionation are a potential alternative for industrial application as additive.Fil: Cabezas, Dario Marcelino. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Diehl, B. W. K.. Spectral Service GmbH Laboratorium fur Auftragsanalytik. Cologne; AlemaniaFil: Tomas, Mabel Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Debris Disks: Probing Planet Formation

    Full text link
    Debris disks are the dust disks found around ~20% of nearby main sequence stars in far-IR surveys. They can be considered as descendants of protoplanetary disks or components of planetary systems, providing valuable information on circumstellar disk evolution and the outcome of planet formation. The debris disk population can be explained by the steady collisional erosion of planetesimal belts; population models constrain where (10-100au) and in what quantity (>1Mearth) planetesimals (>10km in size) typically form in protoplanetary disks. Gas is now seen long into the debris disk phase. Some of this is secondary implying planetesimals have a Solar System comet-like composition, but some systems may retain primordial gas. Ongoing planet formation processes are invoked for some debris disks, such as the continued growth of dwarf planets in an unstirred disk, or the growth of terrestrial planets through giant impacts. Planets imprint structure on debris disks in many ways; images of gaps, clumps, warps, eccentricities and other disk asymmetries, are readily explained by planets at >>5au. Hot dust in the region planets are commonly found (<5au) is seen for a growing number of stars. This dust usually originates in an outer belt (e.g., from exocomets), although an asteroid belt or recent collision is sometimes inferred.Comment: Invited review, accepted for publication in the 'Handbook of Exoplanets', eds. H.J. Deeg and J.A. Belmonte, Springer (2018

    Estudio cinético de la fotodegradación del ión p-hidroxibencenodiazonio en medio polar

    Get PDF
    A study on the photodecomposition of p-hydroxybenzenediazonium ion (PDQ) has been made using chromatographicand spectrophotometric data obtained from UV-irradiated (254 nm) PDQ solutions in acetonitrile and aqueous media.The HPLC and HPLC-mass results indicate that 4-acetamidophenol is the main product formed after the irradiationof PDQ in acetonitrile. This is explained as a consequence of the initial formation of the aryl cation which is laterinvolved in a Ritter’s reaction. A kinetic analysis of the spectrophotometric data reveals that PDQ photodegradation isfaster in acetonitrile (observed rate constant (kobs) = 0.1442 s-1) than in acidifi ed acetonitrile (kobs = 0.009 s-1) indicatinga higher photostability of the protonated species derived from PDQ. The second order constant (0.062 M s-1) found forthe PDQ photodecomposition in phosphate buffer (pH 7) is explained in term of the equilibrium between protonatedand non-protonated species coming from the acid dissociation of PDQSe ha realizado un estudio sobre la fotodescomposición del ión p-hidroxibencenodiazonio (PDQ) basado en los datosespectrofotométricos y cromatográfi cos obtenidos con disoluciones de PDQ expuestas a irradiación UV (254 nm) enmedio de acetonitrilo y agua. Los resultados de HPLC y HPLC-masa (HPLC/MS) indican que el 4-acetamidofenoles el principal producto que se forma tras la irradiación de PDQ en acetonitrilo. Esto se explica como consecuenciade la formación inicial del catión arilo, que posteriormente participa en una reacción de Ritter. El análisis cinéticode los datos espectrofotométricos revela que la fotodegradación de PDQ es más rápida en acetonitrilo (constantede velocidad observada, kobs, = 0,1442 s-1) que en acetonitrilo acidifi cado (kobs = 0,009 s-1), lo que indica una mayorfotoestabilidad de la especie protonada derivada de PDQ. La constante de segundo orden (0,062 M s-1) encontradapara la fotodescomposición de PDQ en tampón fosfato (pH 7) se justifi ca por el establecimiento de un equilibrioentre las especies protonada y no protonada procedentes de la disociación ácida de PDQ

    T- Force o Test de Squat Jump. ¿Cuál es la mejor forma de evaluar la potencia máxima en futbolistas profesionales?

    Get PDF
    In high-performance sport it is important to carry out a control to athletes, which must start from the evaluation of physical abilities every certain period of time; for this you should choose&nbsp; the appropriate tests and instruments&nbsp; considering the gesture and driving pattern of each discipline, as well as the characteristics of each subject. The&nbsp; objective of this research was based on the comparison of two measuring instruments&nbsp; validated in the strength analysis:&nbsp; T-Force® in which the squat and Optogait® test was carried out with the Squat Jump Protocol (SJ) to evaluate maximum power in professional footballers of two football teams in the city of&nbsp; Bogotá. Descriptive study, correlated scope of cross-sectional type. It was attended by 38 male athletes, who performed the SJ tests on Optogait and squat test in T-Force; for the processing and analysis of the data a T test was performed for related samples. Significant differences were found between the results of both tests, where the maximum power obtained was higher with T-Force test, but the deviation of the data was lower in the case of the Optogait. According to the results, sand determined that the best method for measuring maximum power in footballers is the T-Force.En el deporte de alto rendimiento es importante llevar a cabo un control a los deportistas, el cual debe partir de la evaluación de las capacidades físicas cada cierto periodo de tiempo; para esto se deben escoger las pruebas e instrumentos adecuados considerando el gesto y patrón motriz de cada disciplina, así como las características propias de cada sujeto. El objetivo de la presente investigación se basó en la comparación de dos instrumentos de medición validados en el análisis de la fuerza: T-Force® en el cual se realizó el test de sentadilla y Optogait® con el protocolo de Squat Jump (SJ), para evaluar potencia máxima en futbolistas profesionales de dos equipos de futbol de la ciudad de Bogotá. Estudio descriptivo, de alcance correlacional de tipo transversal. Se contó con la participación de 38 deportistas de género masculino, quienes realizaron las pruebas de SJ en Optogait y test de sentadilla en T-Force; para el procesamiento y análisis de los datos se realizó una prueba T para muestras relacionadas. Se encontraron diferencias significativas entre los resultados de ambas pruebas, donde la potencia máxima obtenida fue más alta con el test de T-Force, pero la desviación de los datos fue menor en el caso del Optogait. De acuerdo con los resultados, se determinó que el mejor método para la medición de la potencia máxima en futbolistas es el T-Force

    Qualidade de vida nas pessoas com esquizofrenia: a influência das características sociodemográficas e clínicas e da satisfação com o suporte social

    Get PDF
    Objective: To evaluate the relationship of sociodemographic and clinical characteristics and satisfaction with social support with the quality of life of schizophrenic patients. Methodology: This study included a sample of 268 participants. An interview was conducted to obtain sociodemographic and clinical data, supplemented with two assessment tools used to evaluate quality of life (World Health Organization Quality of Life instrument-Abbreviated version – WHOQOL-Bref) and satisfaction with social support (Social Support Satisfaction Scale – SSSS). Descriptive and inferential analyses were performed. Results: Most individuals were male (63.4%), with a mean age of 45.4 years, single (85.4%), living with their family (62.3%) and unemployed (90.3%). As for clinical characteristics, most had the disease for less than 20 years (50.7%), and 55.6% had at least one hospitalization within the last 5 years. Being employed and having had no hospitalization within the last 5 years were positively correlated with one or more WHOQOL-Bref domains. The results of the variables intimacy (p<0.001) and satisfaction with friends (p<0.001) were independently related to the total WHOQOL-Bref score. Conclusion: Having a job, having had no hospitalization within the last 5 years and having greater satisfaction with social support are factors that positively influence quality of life among schizophrenics. It is therefore crucial that the psychosocial rehabilitation of patients with schizophrenia take these factors into account, increasing the support network, preventing relapses and promoting occupational activities.Objetivo: Avaliar a relação entre as características sociodemográficas e clínicas e a satisfação com o suporte social com a qualidade de vida dos doentes com esquizofrenia. Métodos: A amostra do estudo é de 268 participantes. Foi realizada uma entrevista para obter os dados sociodemográficos e clínicos e aplicados dois questionários para avaliar a qualidade de vida (World Health Organization Quality of Life instrument-Abbreviated version – WHOQOL-Bref) e a satisfação com o suporte social (Escala de Satisfação com o Suporte Social – ESSS). Foram efetuadas análises descritivas e inferenciais. Resultados: A maioria dos indivíduos era do gênero masculino (63,4%), com uma média de idade de 45,4 anos, solteiros (85,4%), vivendo com a família (62,3%) e desempregados (90,3%). Relativamente às características clínicas, 50,7% tinham a doença há menos de 20 anos, e 55,6% estiveram internados pelo menos uma vez nos últimos 5 anos. Os resultados demonstraram que estar empregado e não ter sido internado nos últimos 5 anos estão positivamente relacionados com um ou mais domínios da WHOQOL-Bref. A satisfação com a intimidade (p<0,001) e a satisfação com os amigos (p<0,001) foram independentemente associados ao escore total da WHOQOL-Bref. Conclusão: Ter emprego, não ter hospitalizações nos últimos 5 anos e estar satisfeito com o suporte social são fatores que influenciam positivamente a qualidade de vida dos doentes com esquizofrenia. Por conseguinte, é crucial que esses fatores sejam levados em conta nos programas de reabilitação com o suporte social, aumentando a rede de suporte, evitando recaídas e promovendo atividades ocupacionais.publishe

    Where form and substance meet: using the narrative approach of re-storying to generate research findings and community rapprochement in (university) mathematics education

    Get PDF
    Storytelling is an engaging way through which lived experience can be shared and reflected upon, and a tool through which difference, diversity—and even conflict—can be acknowledged and elaborated upon. Narrative approaches to research bring the richness and vibrancy of storytelling into how data is collected and interpretations of it shared. In this paper, I demonstrate the potency of the narrative approach of re-storying for a certain type of university mathematics education research (non-deficit, non-prescriptive, context-specific, example-centred and mathematically focused) conducted at the interface of two communities: mathematics education and mathematics. I do so through reference to Amongst Mathematicians (Nardi, 2008), a study carried out in collaboration with 20 university mathematicians from six UK mathematics departments. The study deployed re-storying to present data and analyses in the form of a dialogue between two fictional, yet entirely data-grounded, characters—M, mathematician, and RME, researcher in mathematics education. In the dialogues, the typically conflicting epistemologies—and mutual perceptions of such epistemologies—of the two communities come to the fore as do the feasibility-of, benefits-from, obstacles-in and conditions-for collaboration between these communities. First, I outline the use of narrative approaches in mathematics education research. Then, I introduce the study and its use of re-storying, illustrating this with an example: the construction of a dialogue from interview data in which the participating mathematicians discuss the potentialities and pitfalls of visualisation in university mathematics teaching. I conclude by outlining re-storying as a vehicle for community rapprochement achieved through generating and sharing research findings—the substance of research—in forms that reflect the fundamental principles and aims that underpin this research. My conclusions resonate with sociocultural constructs that view mathematics teacher education as contemporary praxis and the aforementioned inter-community discussion as taking place within a third space
    corecore