883 research outputs found

    Trypanosoma cruzi and its components as exogenous mediators of inflammation recognized through Toll-like receptors.

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    Trypanosoma cruzi is the etiologic agent of Chagas' disease, a parasitic disease of enormous importance in Latin America. Herein we review the studies that revealed the receptors from innate immunity that are involved in the recognition of this protozoan parasite. We showed that the recognition of T. cruzi and its components occurs through Toll-like receptors (TLR) 2/CD14. Further, we showed in vivo the importance of the myeloid differentiation factor (MyD88), an adapter protein essential for the function of TLRs, in determining the parasitemia and mortality rate of mice infected with T. cruzi. We also discuss the implications of these findings in the pathophysiology of Chagas' disease

    Genetics of Euglossini bees (Hymenoptera) in fragments of the Atlantic Forest in the region of Viçosa, MG

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    With uncontrolled deforestation, forest fragments remain, which in most cases are in different stages of regeneration and present isolated populations. In the present study we analyzed the genetic patterns of Eulaema nigrita populations in seven Atlantic Forest fragments of different sizes and successional stages in the region of Viçosa, MG. This was done by RAPD molecular markers. We observed that the area of the fragments had no effect on the genetic variability of E. nigrita in the direction predicted by meta-population models. Medium-sized well-preserved woods presented the lowest variability, whereas large and small woods were statistically identical. The evidence supports the notion that rural areas present greater dispersal among fragments, implying greater similarity between the populations of fragments located in rural areas when compared to fragments in urban areas.Com o desmatamento descontrolado das florestas há a formação de fragmentos de mata que, na maioria das vezes, se encontram em distintos estágios de regeneração, mantendo populações isoladas. Neste trabalho foi feita a análise dos padrões genéticos de populações de Eulaema nigrita de fragmentos de mata Atlântica de diferentes tamanhos e estágios sucessionais por meio de marcadores moleculares RAPD da região de Viçosa, MG. Pode-se verificar que a área dos fragmentos não apresentou efeito sobre a variabilidade genética em E. nigrita na direção predita pelos modelos de metapopulação. Uma mata de tamanho médio e bem preservada apresentou a menor variabilidade, enquanto matas grandes e pequenas foram estatisticamente iguais. As evidências sustentam que áreas rurais apresentam maior dispersão entre fragmentos, implicando maior similaridade entre as populações de fragmentos localizados em áreas rurais se comparados com fragmentos nas áreas urbanizadas

    Kalman Filtering in the Air Quality Monitoring

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    Data assimilation is a process where an improved prediction is obtained from a weighted combination between experimental measurements and mathematical model data. In the present work this procedure is applied to pollutant atmospheric dispersion by using a Kalman filter (KF). This is interesting approach, because the KF gives an output in which the balance between the data from the diffusion model and the experimental data is done automaticaly, through the Kalman gain. In addition, the Kalman filter computes the propagation of the error

    Editorial: Neurodegeneration: from Genetics to Molecules

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    Chronic degenerative diseases are one of the major public health problems, particularly those affecting the nervous system. They are characterized by the degeneration of specific cell populations that include several pathologies which contribute significantly to morbidity and mortality in the elderly population. Therefore, in recent years, the study of neuroscience has gained significant importance. Most of these neurodegenerative disorders are the result of a complex interaction between genetic and environmental factors that generate progression and can even determine its severity. The presence of mutations in genes as LRRK2, SNCA, PARK7, PARK2 or PINK1 is associated with Parkinson's disease. Mutations in genes such as APP, PS1 and PS2 are associated with familial Alzheimer's disease; while HTT gene mutations are the cause of Huntington's disease. In most cases, this condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. It is known that these mutations can also alter the proteins function; however, it has not yet been possible to fully understand how some genetic changes cause the disease or influence the risk of developing these disorders. Most symptoms seen in these conditions occurs when specific nerve cells are damaged or die generating a loss in brain communication. Also many of these mutations generate aggregation of intracellular or extracellular proteins affecting cell function and eventually causing neuronal death. It is unclear whether the presence of these aggregates play an important role in nerve cell death during the development of neurodegenerative diseases, or if they are simply part of the response of cells to the disease. Other mutations affect the mitochondrial function generating alterations in energy production and promoting the formation of unstable molecules such as free radicals. Under normal conditions, the harmful effects caused by free radicals, are offset within the cell. However, in pathological conditions, the presence of mutations can alter this process by allowing the accumulation of radicals and damaging or killing cells. On the other hand, we also know that these diseases may not have a direct genetic component, thus, the study of sporadic type neurodegenerative diseases is much more complex. Histopathological lesions as well as the cellular and molecular alterations are generally indistinguishable from familial cases. For this reason, it is important to understand the genetic and molecular mechanisms associated with this type of pathologies. In this sense, this issue aims to understand the molecular processes that occur in the brain, and how these are influenced by the environment, genetics and behavior

    Exploración de la relación entre la alfabetización familiar, las TIC y la competencia lectoescritora

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    Desde el enfoque emergente de la alfabetización se hace hincapié en el impacto del ambiente alfabetizador familiar sobre el desarrollo de la lectoescritura. Así, se ha constatado el influjo del nivel socioeconómico y sociocultural de los progenitores en la práctica de actividades alfabetizadoras en el hogar. Actualmente, la socialización de las TIC ofrece nuevos escenarios que precisan de estudios que contemplen esta variable en la investigación sobre la alfabetización familiar. En este trabajo se presenta una herramienta cuantitativa para la medición del grado de alfabetización familiar y de control parental en la exposición infantil a las TIC, así como el nivel percibido por las familias en la competencia lectoescritora de sus hijos/as. Los resultados de la investigación exploratoria realizada con 100 familias avalan la solidez de la herramienta y evidencian el impacto del nivel socioeconómico y académico de los progenitores en las prácticas de alfabetización y en la gestión del acceso y uso de las TIC por sus hijos/as. Además, se encuentran correlaciones positivas entre un ambiente alfabetizador más rico y una mejor gestión parental de las TIC y el nivel percibido por los progenitores en la competencia lectoescritora de sus hijos/as From the emerging literacy theories, the impact of the family environment on literacy acquisition is emphasized. In this sense, several works have reported the influence of the socioeconomic and sociocultural level of parents in the practice of literacy activities at home. The current socialization of information and communication technologies (ICT) offers new contexts that require the development of family literacy research focused on this variable. This work presents a quantitative tool for measuring the degree of family literacy and parental control in children''s exposure to ICT, as well as the competence perceived by families in their children’s literacy skills. The results of the exploratory research carried out with 100 families confirm the strength of the tool. The results also show the impact of the parents'' socioeconomic and academic level on family literacy practices and on the control of access and use of ICT by their children. Furthermore, positive correlations are found between a richer literacy environment and better parental management of ICTs, and also between a richer literacy envirorment and the level perceived by parents in the literacy skills of their children

    Topical Treatment with Cord Blood Serum in Glaucoma Patients: A Preliminary Report

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    Purpose. To report data happened to be observed in two glaucoma patients treated with Cord Blood Serum (CBS) eyedrops. Design. Case report. Retrospective data analysis Methods. CBS topical eyedrops, characterized in advance for growth factors (GFs) content, were administered for two months with the aim to relieve their subjective symptoms, in two patients who had referred ocular surface discomfort, although in absence of any sign of keratopathy. As patients were also affected by advanced glaucoma at risk of vision loss, and under treatment with hypotensive drugs, they had been also monitored over the same period with IOP controls and Visual field tests in our Unit. Results. During subsequent visits, data from Mean Deviation and Pattern Standard Deviation in the Visual fields were retrospectively collected and compared before and after treatment with CBS, and an amelioration was observed. Conclusions. CBS contains a combination of GFs, which potentially exert a neuroprotective action and candidate CBS as an interesting natural source to be delivered in neurodegenerative ocular disorders. The incidentally observed amelioration in these two patients deserves further investigation in this respec

    Reproductibilidad de un cuestionario que valora la actividad física en adolescentes escolares

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    Introducción: Los cuestionarios de actividad física por lo general son los instrumentos más sencillos y fáciles de aplicar a grandes poblaciones, sin embargo, la capacidad de reproductibilidad varía entre las poblaciones. Objetivo: Analizar la fiabilidad de un cuestionario que valora la Actividad Física en una muestra de escolares adolescentes que viven a elevada altitud por medio de consistencia interna y test re-test. Diseño: Descriptivo-Transversal (Survey). Institución: Universidad Nacional del Altiplano, Puno, Perú. Participantes: Adolescentes escolares de 12 a 17 años. Intervenciones: Fueron seleccionados de forma sistemática 109 escolares de ambos sexos. Se valoró las medidas antropométricas de peso, estatura, estatura sentada y circunferencia del abdomen. Además se aplicó un cuestionario de actividad física con 11 preguntas (test y re-test) con un intervalo de 7 días. Principales medidas: Valoración de la capacidad de reproductibilidad por consistencia interna y estabilidad. Resultados: Los valores de alpha de Cronbach (Consistencia interna) mostraron valores de 0,73 a 0,77 para ambos sexos. El Error Técnico de Medida (ETM) fue de 0,50 a 1,61% y el coeficiente de correlación de Spearman  osciló entre 0,91 a 0,95. Conclusión: El cuestionario de actividad física muestra altos valores de confiabilidad, tanto en su consistencia interna como en la estabilidad de las medidas. Introduction: Physical activity questionnaires usually are the most simple and easy to apply to large populations, however, reproducibility capacity varies between populations. Objective: To analyze the reliability of a questionnaire to assess physical activity in a sample of school adolescents living at high altitude through internal consistency and test re-test. Design: Descriptive, transversal (Survey). Institution: Universidad Nacional del Altiplano, Puno, Peru. Participants: School Teens 12 to 17 years. Interventions: There were systematically selected 109 students of both sexes. We evaluated anthropometric measurements of weight, height, sitting height and circumference of the abdomen. In addition we applied a physical activity questionnaire with 11 questions (test and re-test) with an interval of 7 days. Main measures: capacity rating for internal consistency, reproducibility and stability. Results: Cronbach's alpha values ??(internal consistency) showed values ??from 0.73 to 0.77 for both sexes. Measuring technical error (SEM) was from 0.50 to 1.61% and the Spearman correlation coefficient ranges from 0.91 to 0.95. Conclusion: The physical activity questionnaire shows high values ??of reliability, consistency both internally and in the stability of the measures

    Are braneworlds born isotropic?

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    It has recently been suggested that an isotropic singularity may be a generic feature of brane cosmologies, even in the inhomogeneous case. Using the covariant and gauge-invariant approach we present a detailed analysis of linear perturbations of the isotropic model Fb{\cal F}_b which is a past attractor in the phase space of homogeneous Bianchi models on the brane. We find that for matter with an equation of state parameter γ>1\gamma > 1, the dimensionless variables representing generic anisotropic and inhomogeneous perturbations decay as t0t\to 0, showing that the model Fb{\cal F}_b is asymptotically stable in the past. We conclude that brane universes are born with isotropy naturally built-in, contrary to standard cosmology. The observed large-scale homogeneity and isotropy of the universe can therefore be explained as a consequence of the initial conditions if the brane-world paradigm represents a description of the very early universe.Comment: Changed to match published versio
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