80 research outputs found
The second symmetric product of finite graphs from a homotopical viewpoint
This paper describes the classi cation of the n-fold symmetric product of a finite graph by means of its homotopy type.This paper describes the classi cation of the n-fold symmetric product of a finite graph by means of its homotopy type, having as universal models the n-fold symmetric product of the wedge of n-circles; and introduces a CW-complex called binomial torus, which is homeomorphic to a space that is a strong deformation retract of the second symmetric products of the wedge of n-circles. Applying the above we calculate the fundamental group, Euler characteristic, homology and cohomology groups of the second symmetric product of finite graphs
\u3cem\u3eluxS\u3c/em\u3e in bacteria isolated from 25- to 40-million-year-old amber
Interspecies bacterial communication is mediated by autoinducer-2, whose synthesis depends on luxS. Due to the apparent universality of luxS (present in more than 40 bacterial species), it may have an ancient origin; however, no direct evidence is currently available. We amplified luxS in bacteria isolated from 25- to 40-million-year-old amber. The phylogenies and molecular clocks of luxS and the 16S rRNA gene from ancient and extant bacteria were determined as well. Luminescence assays using Vibrio harveyi BB170 aimed to determine the activity of luxS. While the phylogeny of luxS was very similar to that of extant Bacillus spp., amber isolates exhibited unique 16S rRNA gene phylogenies. This suggests that luxS may have been acquired by horizontal transfer millions of years ago. Molecular clocks of luxS suggest slow evolutionary rates, similar to those of the 16S rRNA gene and consistent with a conserved gene. Dendograms of the 16S rRNA gene and luxS show two separate clusters for the extant and ancient bacteria, confirming the uniqueness of the latter group
Structural insights into the IgE mediated responses induced by the allergens Hev b 8 and Zea m 12 in their dimeric forms
"Oligomerization of allergens plays an important role in IgE-mediated reactions, as effective crosslinking of IgE-Fc epsilon RI complexes on the cell membrane is dependent on the number of exposed B-cell epitopes in a single allergen molecule or on the occurrence of identical epitopes in a symmetrical arrangement. Few studies have attempted to experimentally demonstrate the connection between allergen dimerization and the ability to trigger allergic reactions. Here we studied plant allergenic profilins rHev b 8 (rubber tree) and rZea m 12 (maize) because they represent an important example of cross-reactivity in the latex-pollen-food syndrome. Both allergens in their monomeric and dimeric states were isolated and characterized by exclusion chromatography and mass spectrometry and were used in immunological in vitro experiments. Their crystal structures were solved, and for Hev b 8 a disulfide-linked homodimer was found. Comparing the structures we established that the longest loop is relevant for recognition by IgE antibodies, whereas the conserved regions are important for cross-reactivity. We produced a novel monoclonal murine IgE (mAb 2F5), specific for rHev b 8, which was useful to provide evidence that profilin dimerization considerably increases the IgE-mediated degranulation in rat basophilic leukemia cells.
Procesos no lineales en la ciencia y la sociedad
La existencia de ondas ocurre como una de las formas de manifiestación del movimiento más común en el mundo que nos rodea. Aunque las ondas lineales juegan un papel crucial en el desarrollo de la ciencia en primera aproximación, las ondas de índole no lineal se consideran como las más “realistas” para describir procesos complejos. Una gran posibilidad para el desarrollo de teoría de ondas no lineales se abrió debido a la investigación de solitones, ondas que no cambian de forma y de energía a lo largo de su desplazamiento. En este contexto, en el capítulo de Tatyana Belyaeva y Vladimir Serkin se estudia el efecto túnel cuántico usando ondas no lineales solitónicas de óptica y ondas de materia. Como es conocido, la ecuación diferencial que gobierna estos pulsos ópticos es de la familia de ecuaciones no lineales de Schrödinger, por su analogía con la famosa ecuación de la mecánica cuántica.La evolución de la sociedad en gran medida está soportada por el avance del desarrollo científico. Por ende, la aplicación de conocimientos obtenidos en esfuerzos indagatorios sobre fenómenos que ocurren en el universo es una de las premisas sobre la cual se basa todo desarrollo tecnológico y científico de la humanidad. La investigación en torno a las diferentes manifestaciones de la naturaleza conduce al análisis de entidades interactuantes que condicionan el comportamiento a posteriori de los elementos que la conforman. Es así que el estudio de sistemas interactuantes constituye un tema central en cualquier disciplina científica. Sin embargo, el análisis matemático de estos sistemas no es un problema fácil, de hecho, el estado actual del conocimiento científico y matemático dista aún mucho de comprender a detalle todos los posibles comportamientos de los sistemas complejos. El problema radica principalmente en dos factores: el primero se refiere a la gran cantidad de componentes, variables y parámetros que pueden estar interactuando, lo que obliga a analizar simplificaciones del problema; y el segundo concierne a que las interacciones generalmente no son lineales. Una de las diferencias fundamentales entre procesos lineales y no lineales es que en estos últimos no se cumple el principio de superposición. Cuando el vasto número de procesos naturales no lineales se estudia, comúnmente se modela mediante sistemas de ecuaciones no lineales. Suele ocurrir frecuentemente que la complejidad de fenómenos que ocurren en la naturaleza y sociedad en muchos aspectos es descrita y analizada incluso bajo una misma ecuación diferencial no lineal, incluyendo también en muchos casos la influencia aleatoria de otros agentes externos, por lo que la estocasticidad estará presente de una u otra manera. Esto crea un cuadro relativamente exitoso en vista de que las investigaciones de procesos que ocurren se pueden llevar a cabo en forma aislada, analizarlas abstractamente en el mundo de las matemáticas, para luego volcar todo el arsenal de conocimientos en las respectivas áreas de interés que se realizan
Water intake, hydration status and 2-year changes in cognitive performance: a prospective cohort study
BackgroundWater intake and hydration status have been suggested to impact cognition; however, longitudinal evidence is limited and often inconsistent. This study aimed to longitudinally assess the association between hydration status and water intake based on current recommendations, with changes in cognition in an older Spanish population at high cardiovascular disease risk.MethodsA prospective analysis was conducted of a cohort of 1957 adults (aged 55-75) with overweight/obesity (BMI between >= 27 and = 300 mmol/L (dehydrated). Water intake was assessed as total drinking water intake and total water intake from food and beverages and according to EFSA recommendations. Global cognitive function was determined as a composite z-score summarizing individual participant results from all neuropsychological tests. Multivariable linear regression models were fitted to assess the associations between baseline hydration status and fluid intake, continuously and categorically, with 2-year changes in cognitive performance.ResultsThe mean baseline daily total water intake was 2871 +/- 676 mL/day (2889 +/- 677 mL/day in men; 2854 +/- 674 mL/day in women), and 80.2% of participants met the ESFA reference values for an adequate intake. Serum osmolarity (mean 298 +/- 24 mmol/L, range 263 to 347 mmol/L) indicated that 56% of participants were physiologically dehydrated. Lower physiological hydration status (i.e., greater serum osmolarity) was associated with a greater decline in global cognitive function z-score over a 2-year period (beta: - 0.010; 95% CI - 0.017 to - 0.004, p-value = 0.002). No significant associations were observed between water intake from beverages and/or foods with 2-year changes in global cognitive function.ConclusionsReduced physiological hydration status was associated with greater reductions in global cognitive function over a 2-year period in older adults with metabolic syndrome and overweight or obesity. Future research assessing the impact of hydration on cognitive performance over a longer duration is needed
Utilidad del score SOFA en la predicción de muerte materna en la UCI materna del INMP
Objective: To compare the SOFA score at admission and 24 hours and evaluate its usefulness in predicting maternal death. Materials and methods: A cross-sectional descriptive study of patients admitted to the Maternal ICU of the INMP was carried out from August 2014 to July 2019. Parametric and non-parametric tests were applied according to a previous evaluation of normality and a statistical significance p<0.05. Statistical analysis was performed using the statistical package STATA version 13. Results: The mean age corresponds to 28.32 years. The mean gestational age corresponded to 31.33 weeks; The mean hospital stay was 4.52 days. The area under the curve for SOFA at entry was 0.8818 and the area under the curve for SOFA at 24 hours was 0.9755. P=0.1225. No significant differences were found between them. It was determined that the best cut-off point corresponds to a Score of 6 with a sensitivity that corresponds to 89.29% and a specificity of 79.13%. Conclusions: The SOFA Score adapts well to obstetric patients admitted to Maternal Intensive Care settings, maintaining a cut-off of 6 for admission SOFA with good sensitivity and specificity. (89.29%, 79.13%). The SOFA score is useful in maternal ICU environments and it should be used in our country.Objetivo: Comparar el score SOFA al ingreso y a las 24horas, y evaluar su utilidad en la predicción de la muerte materna. Materiales y métodos: Se realizó un estudio descriptivo de tipo transversal de las pacientes admitidas a la UCI Materna del INMP desde agosto del 2014 a Julio del 2019. Se aplicaron pruebas paramétricas o no paramétricas según evaluación previa de normalidad y se usó una significación estadística p<0.05. El análisis estadístico se realizó utilizando el paquete estadístico STATA versión 13. Resultados: La media de la edad corresponde a 28.32 años. La media de la edad gestacional correspondió a 31.33 semanas; La media de la estancia hospitalaria fue de 4.52 días. El area bajo la curva para el SOFA al ingreso fue de 0.8818 y el area bajo la curva del SOFA a las 24horas fue de 0.9755. P=0.1225. No se encontraron diferencias significativas entre ellas. Se determinó que el mejor punto de corte corresponde a un Score de 6 con una sensibilidad que corresponde a 89.29% y una especificidad de 79.13%. Conclusiones: El Score SOFA se adapta bien a las pacientes obstétricas admitidas en los ambientes de Cuidados Intensivos Materno, manteniendo un corte de 6 para el SOFA de ingreso con una buena sensibilidad y especificidad. (89.29%, 79.13%). El Score SOFA es útil para ser usado en ambientes de UCI y además debe sugerirse su uso en toda UCI obstétrica de nuestro país
Relationship between olive oil consumption and ankle-brachial pressure index in a population at high cardiovascular risk
Background and aims: The aim of this study was to ascertain the association between the consumption of different categories of edible olive oils (virgin olive oils and olive oil) and olive pomace oil and ankle-brachial pressure index (ABI) in participants in the PREDIMED-Plus study, a trial of lifestyle modification for weight and cardiovascular event reduction in individuals with overweight/obesity harboring the metabolic syndrome. Methods: We performed a cross-sectional analysis of the PREDIMED-Plus trial. Consumption of any category of olive oil and olive pomace oil was assessed through a validated food-frequency questionnaire. Multivariable linear regression models were fitted to assess associations between olive oil consumption and ABI. Additionally, ABI ≤1 was considered as the outcome in logistic models with different categories of olive oil and olive pomace oil as exposure. Results: Among 4330 participants, the highest quintile of total olive oil consumption (sum of all categories of olive oil and olive pomace oil) was associated with higher mean values of ABI (beta coefficient: 0.014, 95% confidence interval [CI]: 0.002, 0.027) (p for trend = 0.010). Logistic models comparing the consumption of different categories of olive oils, olive pomace oil and ABI ≤1 values revealed an inverse association between virgin olive oils consumption and the likelihood of a low ABI (odds ratio [OR] 0.73, 95% CI [0.56, 0.97]), while consumption of olive pomace oil was positively associated with a low ABI (OR 1.22 95% CI [1.00, 1.48]). Conclusions: In a Mediterranean population at high cardiovascular risk, total olive oil consumption was associated with a higher mean ABI. These results suggest that olive oil consumption may be beneficial for peripheral artery disease prevention, but longitudinal studies are needed
Adopting a High-Polyphenolic Diet Is Associated with an Improved Glucose Profile: Prospective Analysis within the PREDIMED-Plus Trial
Previous studies suggested that dietary polyphenols could reduce the incidence and complications of type-2 diabetes (T2D); although the evidence is still limited and inconsistent. This work analyzes whether changing to a diet with a higher polyphenolic content is associated with an improved glucose profile. At baseline, and at 1 year of follow-up visits, 5921 participants (mean age 65.0 ± 4.9, 48.2% women) who had overweight/obesity and metabolic syndrome filled out a validated 143-item semi-quantitative food frequency questionnaire (FFQ), from which polyphenol intakes were calculated. Energy-adjusted total polyphenols and subclasses were categorized in tertiles of changes. Linear mixed-effect models with random intercepts (the recruitment centers) were used to assess associations between changes in polyphenol subclasses intake and 1-year plasma glucose or glycosylated hemoglobin (HbA1c) levels. Increments in total polyphenol intake and some classes were inversely associated with better glucose levels and HbA1c after one year of follow-up. These associations were modified when the analyses were run considering diabetes status separately. To our knowledge, this is the first study to assess the relationship between changes in the intake of all polyphenolic groups and T2D-related parameters in a senior population with T2D or at high-risk of developing T2
Capitulo 1. Ciencias Médicas y de la Salud
En los últimos años se ha observado un incremento de las enfermedades no transmisibles dentro de ellas se destaca el cáncer por su alta incidencia e impacto en la mortalidad (WHO, 2018). En las enfermedades transmisibles, si bien hay una disminución, las micosis se han incrementado, agravando el panorama la resistencia a los antimicóticos (Pfaller, 2012). Objetivo: Evaluar la actividad antifúngica y citotóxica in vitro de extractos etanólicos de Lantana camara L., Petiveria alliacea L. y Lippia dulcis T. Metodología: Se realiza un estudio experimental con tres componentes. Primero: evaluar las características fitoquímicas de los extractos etanólicos de Lantana camara l., Petiveria alliacea l. y Lippia dulcis t. mediante Cromatografía en Capa Delgada (CCD) y pruebas de coloración y precipitación (Sanabria, 1983). Segundo: evaluación de la actividad antifúngica de los extractos etanólicos frente a Candida albicans ATCC 10231, Candida parasilopsis ATCC 22019 y Saccharomyces cerevisiae ATCC 260 por técnica de difusión con disco (CSL 44-A), y la CMI mediante dilución de acuerdo con García y col 2003. Análisis de datos (ANOVA). Tercero: evaluación de actividad citotóxica de extractos etanólicos en líneas celulares de cáncer de seno MCF-7, y cáncer de cuello uterino SiHa, mediante la prueba de MTT (metil-tiazol-tetrazolio), según Mosmann (1983). Resultados: Las pruebas fitoquímicas realizadas confirmaron la presencia en abundancia de metabolitos tipo esteroides y/o terpenoides en las tres especies y tipo flavonoide incluyendo leucoantocianidinas en presencia moderada a abundante especialmente en P. alliacea y L. dulcis, mientras que en L. cámara se presentaron de forma escasa a moderada. Para La evaluación de actividad antifúngica se ha estandarizado mediante espectofotometría el inoculo de 1x10⁶ - 5x10⁶ UFC/mL (0,5 McFarland) a 550 nm (abs 0,125-0,128) respaldado por recuento en SDA + Cloranfenicol y se estableció el control positivo (Fluconazol 25μg) con prueba de difusión. Se evalúa DMSO como solvente y control negativo para continuar pruebas con extractos. En relación con evaluación de actividad citotóxica, las líneas celulares SiHa y MCF-7 se mantienen en medio DMEM 10% SFB y 1% de antibiótico. Se inició la evaluación de extracto etanólico de P. alliacea, en la línea celular SiHa, incluyendo Doxorrubicina como control de citotoxicidad al 0.14 μg/mL en forma preliminar para evaluar el porcentaje de viabilidad celular
Spread of a SARS-CoV-2 variant through Europe in the summer of 2020
[EN] Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3,4,5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes.S
- …