Hydrodynamic Simulations of the Interaction between an AGB Star and a Main Sequence Companion in Eccentric Orbits

The Rotten Egg Nebula has at its core a binary composed of a Mira star and an A-type companion at a separation >10 au. It has been hypothesized to have formed by strong binary interactions between the Mira and a companion in an eccentric orbit during periastron passage ~800 years ago. We have performed hydrodynamic simulations of an asymptotic giant branch star interacting with companions with a range of masses in orbits with a range of initial eccentricities and periastron separations. For reasonable values of the eccentricity, we find that Roche lobe overflow can take place only if the periods are <<100 years. Moreover, mass transfer causes the system to enter a common envelope phase within several orbits. Since the central star of the Rotten Egg nebula is an AGB star, we conclude that such a common envelope phase must have lead to a merger, so the observed companion must have been a tertiary companion of a binary that merged at the time of nebula ejection. Based on the mass and timescale of the simulated disc formed around the companion before the common envelope phase, we analytically estimate the properties of jets that could be launched. Allowing for super-Eddington accretion rates, we find that jets similar to those observed are plausible, provided that the putative lost companion was relatively massive.Comment: accepted for publication in MNRA

A Física aplicada à qualidade alimentar: identificação de metais por “pixe” em castanhas

A concentração na castanha de minerais como o cálcio, potássio, o magnésio e outros tem sido estudada tradicionalmente por absorção atómica ou por espectrofotometria de UV-VIS [1-2]. Neste trabalho foi estudada a composição elementar de duas variedades (Longal e Judia) de castanha europeia (Castanea sativa Mill.) com a técnica PIXE (Proton Induced X-ray Emission). Os resultados preliminares mostram que a composição difere de acordo com a variedade, nos elementos maioritários e nos minoritários. Este estudo é parte de um projecto mais amplo, que visa avaliar o efeito do processamento pós-colheita de alimentos com feixe de electrões e raios-X.Coordinated Research Project D61024 ‘‘Development of New Applications of Machine Generated Food Irradiation Technologies’’, Agência Internacional de Energia Atómica (AIEA)

Heavy elements in chestnuts

Chestnut fruit (CasChestnuts, Castanea sativa, heavy elements, PIXEtanea sativa Miller) are an important food resource in several countries. Portugal is the third largest European producer, with an average production of 25 thousand tons [1], being mainly produced in the North region of Trás-os-Montes. Earlier studies on chestnuts elemental composition were performed by atomic absorption to detect Ca, Mg, Na, K, Cu, Fe, Mn and Zn or by UV-VIS spectrophotometry to detect P [2-3]. In this work the elemental composition of two cultivars (Longal and Judia) of Castanea sativa Miller were studied by means of PIXE (Proton Induced X-ray Emission), using a broad proton beam at CTN-IST, Lisbon. Element identification (from Si to Pb) and quantification (following the method described in [4]) was done. Preliminary results show different composition according with the cultivar, not only in the major and minor elements (as it is described in the bibliography) but also in the trace elements, which includes the presence of Pb and other heavy elements. These preliminary results are part of a wider project that aims to evaluate chestnut fruits decontamination treatment with high energy electron beam and X-rays technology.This work was developed within the Coordinated Research Project D61024 ‘‘Development of New Applications of Machine Generated Food Irradiation Technologies’’ financed by the International Atomic Energy Agency (IAEA)

Influence of CYP1A1*2C on High Triglyceride Levels in Female Mexican Indigenous Tarahumaras

Background and Aims High triglyceride levels are closely related to cardiovascular disease. Its development lays on age, diet, physical activity, ethnicity and genetic factors. Among the last, the CYP1A1*2C allele has an influence on the metabolism of cholesterol and other fatty acids. We undertook this study to determine the frequency of CYP1A1*2C and its association with triglyceride levels in Mexican indigenous Tarahumaras and Tepehuanos. Methods Anthropometric and biochemical data were recorded. Genotyping of CYP1A1*2C by RT-PCR was done in 110 Tepehuano, 69 Tarahumara and 64 Mestizo. Results Significant differences in age, waist diameter, BMI, creatinine, glucose, cholesterol, triglycerides, HDL and VLDL measurements were found between Tarahumaras and Tepehuanos (p <0.05). Additionally, Tarahumara women showed the highest values of waist diameter, BMI and triglycerides (p <0.05). It was found that Tarahumaras showed a significant association between high triglyceride levels and CYP1A1*2C allele (OR = 2.57; 95% CI 1.12–5.88, p = 0.024) under a recessive inheritance model. However, the Tepehuano group showed a significant protective association between normal triglyceride levels and CYP1A1*2C polymorphism (OR = 0.28; 95% CI 0.10–0.80, p = 0.015) following a dominant inheritance model. The same pattern was observed after analysis with females of both ethnicities. Conclusion A significant association between CYP1A1*2C and high triglyceride levels in Amerindian Tarahumaras from Chihuahua has been found; this allele was significantly associated with normal triglyceride levels in Tepehuanos from Durango, Mexico. Further studies are needed to elucidate the genetic role of CYP1A1 in cardiovascular disease susceptibility

Improving Parental Engagement for Latino Youths\u27 Educational Success: Lessons from Juntos Oregon

Research has shown that more efforts are needed to increase high school completion and postsecondary enrollment among Latino youths. However, little is known regarding efforts that engage both Latino youths and their parents. To address this gap, we surveyed Juntos Oregon participants to examine the school and community context Latino youths and their families face in the educational journey and identify effects of the Juntos program. Results showed that in a context of persistent discrimination and unfair treatment, Juntos workshops increased the sense of school and community connectedness among Latino parents. Increases in academic planning and motivation occurred as well. Extension may increase its educational impact by strengthening connections and promoting engagement between schools and Latino families

Triatoma gerstaeckeri (Hemiptera: Reduviidae) infectada con Trypanosoma cruzi en Nuevo León, México, y capacidad patógena de la cepa regional

Introduction: Four species of triatomines have been reported in Nuevo León, northeast (NE) México, but Triatoma gerstaeckeri has only been recorded from a peridomestic dwelling.Objectives: To assess the natural infection index (NII) of Trypanosoma cruzi in triatomines and the infestation index (II) of T. gerstaeckeri collected in a suburban locality, and to collect histopathological data to understand tissue tropism of the regional T. cruzi strain (strain NE) obtained from the vectors collected after an experimental inoculation in Mus musculus.Materials and methods: Triatomines were collected from 85 houses and peridomiciles in Allende, Nuevo León. Stool samples were obtained to determine the T. cruzi NII and were used in an experimental mice infection.Results: A total of 118 T. gerstaeckeri were captured, and 46 (adults and nymphs) were collected inside the same house (II=1.17%). Thirty-seven reduvids were infected with T. cruzi (NII=31.3%). Tissue tropism of the T. cruzi NE strain was progressive in skeletal muscle, myocardial, and adipose tissues and was characterized by the presence of intracellular amastigotes and destruction of cardiac myocells.Conclusions: The presence of naturally infected domiciliary vectors is an important risk factor for public health in the region considering that these vectors are the principal transmission mechanism of the parasite. The T. cruzi NE strain has similar virulence to that of other Mexican and Texan strains and caused chagasic infections in 11 of 12 mice.Introducción. En Nuevo León, localizado en el noreste de México, existen cuatro especies de triatominos, de las cuales Triatoma gerstaeckeri ha sido la única reportada en peridomicilios.Objetivos. Evaluar el índice de infección natural de Trypanosoma cruzi en los triatominos y el índice de infestación de T. gerstaeckeri en una localidad suburbana, y obtener datos histopatológicos para comprender el tropismo tisular de la cepa regional (cepa NE) de T. cruzi obtenida de los vectores recolectados después de la infección experimental en Mus musculus.Materiales y métodos. La recolección de triatominos se llevó a cabo en 85 casas y peridomicilios de Allende, Nuevo León, México. Se obtuvieron muestras de las deyecciones para conocer el índice de infección natural por T. cruzi y, con estas, se hicieron inoculaciones experimentales en ratones.Resultados. Se capturaron 118 especímenes de T. gerstaeckeri, 46 (adultos y ninfas) en el mismo domicilio (índice de infestación=1,17 %). Treinta y siete redúvidos estaban infectados con T. cruzi (índice de infección natural, 31,3). El tropismo tisular de la cepa NE de T. cruzi fue progresivo en músculo esquelético, miocardio y tejido adiposo, y se caracterizó por la presencia de amastigotes intracelulares con destrucción de células cardiacas.Conclusiones. La presencia de vectores domiciliarios naturalmente infectados con T. cruzi, es un factor de riesgo importante para la salud pública de la región, considerando que este es el principal mecanismo de la transmisión del parásito y que la cepa NE de T. cruzi tiene una virulencia similar a la de otras cepas mexicanas y texanas, y causó infección chagásica en 11 de los 12 ratones inoculados

Análisis comparativo del grado de desarrollo de la coordinaciónmotriz en niños y niñas de educación preescolar

El objetivo de la investigación fue comparar por género la coordinación motriz fina, coordinación motriz gruesa y coordinación motora total de niños y niñas de prescolar. El diseño del estudio fue descriptivo comparativo, con muestreo por conveniencia, participaron 179 niños y niñas de una edad promedio de 4 y 5 años matriculados en jardines de niños para educación prees-colar de la ciudad de Mexicali, Baja California, México. Se utilizó como instrumento de evaluación el inventario de desarrollo Battelle para determinar la coordinación motriz fina, coordinación motriz gruesa y coordinación motora total. La igualdad de la varianza se calculó mediante la prueba t Student para muestras independientes, resultando por género menor a α≤ 0.05; la coordinación motriz gruesa (P-Valor=.000), coordinación motriz fina (P-Valor=.002) y la coordinación motora total (P-Va-lor=.000). La comparación mostró diferencias significativas en diversas capacidades motoras entre niños y niñas, por lo anterior es necesario mejorar las deficiencias motoras por medio de la educación física que permitan un óptimo desarrollo motriz, con actividades igualitarias y mayores oportunidades de participación para las niñaThe aim of the study was to compare by gender the fine motor coordination, gross motor coordination and total motor coordination of kindergarten children. The research design was comparative descriptive, with convenience sampling, involving 179 children of an average age of 4 and 5 years enrolled in kindergartens for preschool education in the city of Mexicali, Baja California. Mexico. The Battelle development inventory was used as an evaluation instrument to determine fine motor coordination, gross motor coordination and total motor coordination. The equality of the variance was calculated by the Student t test for independent samples resulting in gender less than α≤ 0.05; gross motor development (P-Value=.000), fine motor development (P-Value=.002) and general motor development (P-Value=.000). The comparison showed significant differences in motor coordination between boys and girls, therefore it is necessary to improve motor deficiencies through physical education that allow optimal movement development, with equal activities and greater opportunities for participation for girls.Actividad Física y Deport

Association of trypanosoma cruzi infection with risk factors and electrocardiographic abnormalities in northeast Mexico

Background: American trypanosomiasis is a major disease and public health issue, caused by the protozoan parasite Trypanosoma cruzi. The prevalence of T. cruzi has not been fully documented, and there are few reports of this issue in Nuevo Leon. The aim of this study was to update the seroprevalence rate of T. cruzi infection, including an epidemiological analysis of the risk factors associated with this infection and an electrocardiographic (ECG) evaluation of those infected. Methods: Sera from 2,688 individuals from 10 municipalities in the state of Nuevo Leon, Mexico, were evaluated using an enzyme-linked immunosorbent assay and an indirect hemagglutination assay. An ECG case–control study was performed in subjects seropositive for T. cruzi and the results were matched by sex and age to seronegative residents of the same localities. A univariate analysis with χ 2 and Fisher’s exact tests was used to determine the association between seropositivity and age (years), sex, and ECG changes. A multivariate analysis was then performed to calculate the odd ratios between T. cruzi seropositivity and the risk factors. Results: The seropositive rate was 1.93% (52/2,688). In the ECG study, 22.85% (8/35) of the infected individuals exhibited ECG abnormalities. Triatoma gerstaeckeri was the only vector reported. The main risk factors were ceiling construction material (P ≤ 0.0024), domestic animals (P ≤ 0.0001), and living in rural municipalities (P ≤ 0.0025). Conclusions: These findings demonstrate a 10-fold higher prevalence of Chagas disease than previously reported (0.2%), which implies a serious public health threat in northeastern Mexico. The epidemiological profile established in this study differs from that found in the rest of Mexico, where human populations live in close proximity to domiciliary triatomine