180 research outputs found
The Immature Gut Barrier and Its Importance in Establishing Immunity in Newborn Mammals
The gut is an efficient barrier which protects against the passage of pathogenic microorganisms and potential harmful macromolecules into the body, in addition to its primary function of nutrient digestion and absorption. Contrary to the restricted macromolecular passage in adulthood, enhanced transfer takes place across the intestines during early life, due to the high endocytic capacity of the immature intestinal epithelial cells during the fetal and/or neonatal periods. The timing and extent of this enhanced endocytic capacity is dependent on animal species, with a prominent non-selective intestinal macromolecular transfer in newborn ungulates, e.g., pigs, during the first few days of life, and a selective transfer of mainly immunoglobulin G (IgG), mediated by the FcRn receptor, in suckling rodents, e.g., rats and mice. In primates, maternal IgG is transferred during fetal life via the placenta, and intestinal macromolecular transfer is largely restricted in human neonates. The period of intestinal macromolecular transmission provides passive immune protection through the transfer of IgG antibodies from an immune competent mother; and may even have extra-immune beneficial effects on organ maturation in the offspring. Moreover, intestinal transfer during the fetal/neonatal periods results in increased exposure to microbial and food antigens which are then presented to the underlying immune system, which is both naïve and immature. This likely stimulates the maturation of the immune system and shifts the response toward tolerance induction instead of activation or inflammation, as usually seen in adulthood. Ingestion of mother's milk and the dietary transition to complex food at weaning, as well as the transient changes in the gut microbiota during the neonatal period, are also involved in the resulting immune response. Any disturbances in timing and/or balance of these parallel processes, i.e., intestinal epithelial maturation, luminal microbial colonization and mucosal immune maturation due to, e.g., preterm birth, infection, antibiotic use or nutrient changes during the neonatal period, might affect the establishment of the immune system in the infant. This review will focus on how differing developmental processes in the intestinal epithelium affect the macromolecular passage in different species and the possible impact of such passage on the establishment of immunity during the critical perinatal period in young mammals
Development of a stress-induced martensitic transformation criterion for a Cu-Al-Be polycrystalline shape memory alloy undergoing uniaxial tension
This study presents a criterion for predicting the martensitic variants (MVs) that appear during the stress-induced martensitic transformation (SIMT) in a polycrystalline sample of Cu 11.5% wt. Al 0.5% wt. Be under simple tension. Our criterion is based on crystallographic parameters, such as the crystal orientation and Schmid factor (SF). The displacement vector fields (DVFs) were obtained in the observation system by a mathematical model and were used to distort the boundary of a set of grains. From the DVF, the strain tensor for each grain was obtained, and the strain ratio (SR) in the observation system was calculated. Electron backscattering diffraction (EBSD) measurements were performed to determine the crystal orientation of the grains. The inverse SF was used to determine the in-plane stress transformation diagrams (STDs) for each studied grain. The combination of a balance criterion (BC) and STD provided a criterion that allowed us to predict the possible order of stress-induced MVs formed as a function of the crystal orientation and thermomechanical parameters of the shape memory alloy (SMA) with higher accuracy than when using the criteria separately. To validate our criteria, we tested other researchers published results. Our results were in agreement and were capable of predicting the stress-induced MVs in a polycrystalline SMA.The authors wish to thank the Coordinacion de estudios de posgrado (CEP)-UNAM, PAPIIT project number TI 02414 and Instituto de Tecnologia de Materiales-UPV for financial support. The authors are grateful to the Electron Microscopy Service of the UPV and especially to Manuel Josep Planes Insausti and Jose Luis Moya Lopez. The authors are grateful to Martin Estrada Arcos, Alberto Higuera Garcia, and Antonio Gonzalez Montaiio for their technical support.García Castillo, F.; Cortés Pérez, J.; Amigó Borrás, V.; Sánchez Arévalo, P.; Lara Rodríguez, G. (2015). Development of a stress-induced martensitic transformation criterion for a Cu-Al-Be polycrystalline shape memory alloy undergoing uniaxial tension. Acta Materialia. 97:131-145. https://doi.org/10.1016/j.actamat.2015.06.044S1311459
Improving performance and capacity utilization in cloud storage for content delivery and sharing services
Content delivery and sharing (CDS) is a popular and cost effective cloud-based service for organizations to deliver/share contents to/with end-users, partners and insider users. This type of service improves the data availability and I/O performance by producing and distributing replicas of shared contents. However, such a technique increases the storage/network resources utilization. This paper introduces a threefold methodology to improve the trade-off between I/O performance and capacity utilization of cloud storage for CDS services. This methodology includes: i) Definition of a classification model for identifying types of users and contents by analyzing their consumption/ demand and sharing patterns, ii) Usage of the classification model for defining content availability and load balancing schemes, and iii) Integration of a dynamic availability scheme into a cloud based CDS system. Our method was implemented ¿This work was partially supported by the Spanish Ministry of Economy, Industry and Competitiveness under the grant TIN2016-79637-P ”Towards Unification of HPC and Big Data Paradigms
Estudio clínico morfológico de la deformación del borde dorsal del cuello del burro de raza andaluza
The aim of this study was to a clinical, morphological of deformation dorsal neck edge on donkeys Andalusian in Bodonal de la Sierra, Extremadura, Spain. We studied a total of 31 donkeys. Clinical examination was performed and morphological considering weight and body condition was measured cervical perimeter. Deformation of the dorsal edge of the neck in all cases studied was evident. Morphological study was to consider the deformation of the dorsal edge of the neck considering the crest of the neck (score of 1 to 5) evidenced. 0 and 1 score-no donkey under these categories. Score 2 - 42 % Score. 3 - 32% score. 4 - 3 % and score 5 - 23%. The statistical results of the peso versus the cervical neck circumference showed a correlation coefficient of 0.773 and the score grade obese neck and body condition was 0.240. In conclusion lesions consistent with deformation of the dorsal edge of the neck in Andalusian breed donkeys were observed.Se plantea como objetivo un estudio clínico morfológico de la deformación del borde dorsal del cuello en burros de raza Andaluza en Bodonal de la Sierra, Extremadura-España. Fueron estudiados un total de 31 burros. Se practicó un examen clínico y morfológico considerando condición corporal peso y se midió el perímetro cervical. Se evidenció deformación del borde dorsal del cuello en todos los casos estudiados. El estudio morfológico para considerar la deformación del borde dorsal del cuello considerando la cresta de la nuca (puntuación del 1 al 5) evidencio: para Puntuación 0 y 1.- ningún burro bajo estas categorías. Puntuación 2.- 42%, Puntuación 3.- 32%, Puntuación 4.- 3% y Puntuación 5.- 23%. Los resultados estadísticos del peso versus el perímetro cervical del cuello presentaron un coeficiente de correlación de 0.773 y para el grado puntuación del cuello obeso y condición corporal fue de 0.240. En conclusión se observaron lesiones compatibles con la deformación del borde dorsal del cuello en burros de raza Andaluza
Student mentoring program at the Faculty of Pharmacy, University of Seville (2006/07 - present): SWOT analysis carried out by mentor students
El “Programa de Alumnos Tutores” (LCC, Facultad de Farmacia US) se viene realizando
ininterrumpidamente desde 2006/07 hasta la actualidad. Propósito: tutela de alumnos de nuevo ingreso por
parte de alumnos de cursos superiores (AATT) bajo la supervisión de Profesores Tutores. Pretende generar
una actitud responsable en los AATT y favorecerles el desarrollo de habilidades sociales. El objetivo de
este trabajo es recoger las opiniones de los AATT (algunos comenzaron en ediciones anteriores y
continúan desinteresadamente). Se aborda mediante un análisis DAFO. Conclusión: se han detectado
factores estratégicos críticos, para una vez identificados, usarlos y apoyar en ellos la marcha del
“Programa de Alumnos Tutores”, consolidando las fortalezas, minimizando las debilidades, aprovechando
las ventajas de las oportunidades, y eliminando o reduciendo las amenazas.The "Student Mentor Program" (Faculty of Pharmacy, US) has been running since 2006/07 – to present.
Purpose: to mentor new students by senior students (Mentor Students) under the supervision of mentor
professors. It aims to generate a responsible attitude in students and tutors to encourage the development
of social skills. Objective: To collect the views of mentor students (some started in previous years and
continue to selflessly), through a SWOT analysis. Conclusion: it has been found critical strategic factors. It
intends to use these factors for strengthening the "Student Mentor Program"
Aproximación a la presencia de SPD y microorganismos en agua embotellada
Poca información existe en la literatura acerca de la calidad química referente a subproductos de desinfección (SPD) y su relación con la microbiología del agua embotellada. Por tanto, se evaluó el contenido de trihalometanos (THM) y de ácidos haloacéticos (AHA) como principales SPD en siete marcas de agua embotellada del mercado colombiano, al igual que la presencia de indicadores microbiológicos, enterobacterias, aerobios mesófilos, hongos y levaduras. Los resultados mostraron valores máximos de 135 y 140 mg/l de THM y AHA totales, así como incumplimiento del 28% de la norma propuesta por la FDA. Se encontró la presencia de alguno de los indicadores microbiológicos en el 69% de las muestras e incumplimiento de la norma colombiana de agua potable en el 30%. La relación entre la cantidad de SPD y la calidad microbiológica fue diversa, observándose un escenario recomendable de baja concentración de SPD y microorganismos en dos de las marcas evaluadas. Finalmente, se requiere mayor información para analizar el efecto de la presencia de levaduras como indicador de cambios organolépticos en el agua y su posible relación con la proliferación de otro tipo de microorganismos
Geomorphological record of extreme wave events during Roman times in the Guadalquivir estuary (gulf of cadiz, SW Spain): An archaeological and paleogeographical approach
Analysis of the geological record has made it possible to delimit for theGuadalquivir estuary the traces of extreme wave events (EWEs) during the Roman period in the Iberian Peninsula (218 BCE to 476 CE). The largest event occurred in the 2nd-3rd century CE. It generated clearly visible erosive effects in the coastal barriers, including washover fans and erosional scarps. In the inner estuary, however, the effects were minor: crevasse splays that broke levees and cheniers, as well as a residual sedimentary lag. The significant development of the spits protected the inner estuary from the marine incursion, which only caused a water level rise with low-regime waves. Correlation of the geomorphological and sedimentary marks left by this event with the archaeological and geological evidence of other events recognized elsewhere in the Gulf of Cadiz effectively argues for a tsunami as to the nature of the 2nd-3rd century CE event. Yet this and the other identified EWEs in the Guadalquivir estuary during the pre-Roman and the Roman period all fit a model of paleogeographic evolution dominated by processes of coastal progradation and estuarine infilling. Radiocarbon dating, geomorphological analysis, and historical references fail to warrant the so-called '218-209 BCE' Atlantic tsunami, as hypothesized in the received scientific literature. In pre-Roman and Roman times, human occupation at the mouth of the Guadalquivir River was strongly influenced by various geodynamic processes, the location of the settlements being contingent upon dependable, fast communication with the sea and, above all, upon adequate protection from EWEs, on the leeward side of spits. Progressive progradation of these coastal barriers combined with the gradual infilling of the estuary to make navigation to open sea increasingly difficult and, eventually, to result in the abandonment of settlements
Efecto de la aplicación tópica de insulina en la cicatrización por segunda intención en la piel de tortugas: estudio morfométrico
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