1,636 research outputs found
Paleomicrobiological Study in Dental Calculus: Streptococcus mutans
Morphological types of bacterial remains preserved in ancient tartar of teeth from extinct human groups, which included some communities of coastal gatherers, fishermen, hunters, and farmers, and those practicing a mixed economy, were analyzed. Previous studies have shown the presence of bacteria in ancient tartar. The aim of this work was to determine whether Streptococcus mutans was present in ancient populations (500-12,000 years old). Teeth samples were from ancient skulls obtained from different anthropological collections: the north and south of Chile (before the Spanish conquest), Palencia, Spain, and an eastern Mediterranean region (Levant). Optical microscopy showed Gram positive and Gram negative bacteria. Scanning electron microscopy identified morphological types of bacteria. Transmission electron microscopy enabled categorization of bacterial structures. Fluorescence microscopy helped label and identify S. mutans, using polyclonal antibodies.
Bacterial morphotypes were related to different subsistence patterns. Hunters, fishermen, and gatherers had a less diverse flora with bacillary and coccal morphotypes. Agricultural groups showed greater diversity with additional filamentous and spiral morphotypes. The best preserved ultrastructural feature was the cell wall. The existence and colonization capacity of the mutans-like streptococci preserved in tartar was established for the ancient populations studied, with the exception of Cerro Sotta (south of Chile). Hence, their occurrence could not be related to diet or subsistence pattern
Structure-activity relationships based on 3D-QSAR CoMFA/CoMSIA and design of aryloxypropanol-amine agonists with selectivity for the human β3-adrenergic receptor and anti-obesity and anti-diabetic profiles
Indexación: Scopus.Acknowledgments: This work was supported by FONDECYT No. 11130701. We would also like to thank fDoTr CthLeafbr efeora vthaeil afrbeilei tayvoafiltahbeilsitoyf towfa trheer seoqfutwireadret orecqaulciureladt etothcealAcuDla(thet ttph:e/ A/dDt c(lhatbt.pw:/e/dbstc.cloabm.w/seobfst.wcoamre/-stoofotlws aarned-tools and http://teqip.jdvu.ac.in/QSAR_Tools/). SDG. Conflicts of Interest: The authors declare no conflict of interest. Conflicts of Interest: The authors declare no conflict of interest.The wide tissue distribution of the adrenergic β3 receptor makes it a potential target for the treatment of multiple pathologies such as diabetes, obesity, depression, overactive bladder (OAB), and cancer. Currently, there is only one drug on the market, mirabegron, approved for the treatment of OAB. In the present study, we have carried out an extensive structure-activity relationship analysis of a series of 41 aryloxypropanolamine compounds based on three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques. This is the first combined comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) study in a series of selective aryloxypropanolamines displaying anti-diabetes and anti-obesity pharmacological profiles. The best CoMFA and CoMSIA models presented values of r2 ncv = 0.993 and 0.984 and values of r2 test = 0.865 and 0.918, respectively. The results obtained were subjected to extensive external validation (q2, r2, r2 m, etc.) and a final series of compounds was designed and their biological activity was predicted (best pEC50 = 8.561). © 2018 by the authors.https://www.mdpi.com/1420-3049/23/5/119
Cartografía local de áreas quemadas empleando teledetección
Gajardo, J.; Mena, C.; Ormazábal Y. y Morales, Y.
Centro de Geomática. Universidad de Talca. Casilla 747, Talca. Chile.Se realizó la cartografía de un incendio forestal, ocurrido en la localidad de San José de
Mingre, comuna de San Javier, Región del Maule, durante la temporada 2003 - 2004. El
estudio empleó una serie de índices, transformaciones y métodos multipaso, efectuados
sobre datos de una imagen del sensor TM a bordo de la plataforma Landsat. En una primera
fase, la metodología empleada incluyó las correcciones geométricas, radiométricas y
atmosféricas de la imagen satelital para obtener medidas de reflectancia. Posteriormente, se
calcularon índices (NDVI, BAI), y la transformación (ALME). Se discriminaron de forma
muy clara las zonas que se encontraban quemadas para la extracción de pixels semillas,
posteriormente se analizó la separabilidad espectral de cada banda. En una segunda fase, se
emplearon los pixels semillas para introducirlos en el algoritmo de crecimiento que
permitió cartografiar el incendio. La información (combustible quemado, fecha del
siniestro, recursos empleados), así como las mediciones reales de la superficie y perímetro
del incendio fueron proporcionadas por CONAF Región del Maule. Sobre estas mediciones
se contrastaron los resultados obtenidos en el procesamiento de la imagen Landsat. Los
resultados indican una fiabilidad global que oscila entre 70 y 95% para las diversas técnicas
empleadas, con una amplia variedad entre los índices espectrales y el crecimiento de
regiones. Las conclusiones muestran que es factible emplear métodos de cuantificación de
área quemada basados en datos remotos, demostrando su utilidad en casos de incendios de
gran magnitud y de difícil acceso en donde es inviabl
Índices de área verde y cobertura vegetal para la ciudade de Parral (Chile), mediante Fotointerpretación y GIS
Mena, C (reprint author), Univ Talca, Fac Cs Forestales, Avda Lircay S-N, Talca, Chile.he importance of the green areas is increasing since they are an important factor in the health and welfare of urban population. Therefore, in Parral city, in Central Chile, it was quantified and analyzed the availability of green areas and vegetation cover, using aerial photographs scale 1: 10000 and Geographic Information Systems (GIS). In a first stage, urban street trees were quantified through a simple random sample of twenty-four units with field measurements combined with measurements on aerial photographs, from which it was obtained the surface provided. Subsequently, through the creation of GIS layers, the surface of existing green areas and available open spaces were obtained. In addition, through supervised digital classification, the surface covered by urban forestry in private spaces was calculated. Quantity indexes show that Parral city currently has 12.72 ha of green areas, equivalent to 4.82 m(2)/hab, which implies a green area frequency of 0.022 m(2)/m(2). These values could be improved, if the available open space are incorporated and thereby reach 12.06 m(2) per inhabitant. In relation with availability indexes it was established that the average of accessibility to a green area is 327.2 m. Moreover, assuming a buffer of 200 m around the green areas, it was determined that there are 5160 houses with the basic service (56.4%). By incorporating the available open spaces, these values decrease significantly obtaining an average of accessibility to a green area of 213.7 m and coverage of basic service of 79.2%. Finally, it was estimated that the existing vegetation within the urban blocks (urban forest in private spaces) represents an important resource 17.8 times larger than urban street trees, so it should be considered within the municipal plans and policies
A New Kind of Quinonic-Antibiotic Useful Against Multidrug-Resistant S. aureus and E. faecium Infections
Indexación: Scopus.A rapid emergence of resistant bacteria is occurring worldwide, endangering the efficacy of antibiotics and reducing the therapeutic arsenal available for treatment of infectious diseases. In the present study, we developed a new class of compounds with antibacterial activity obtained by a simple, two step synthesis and screened the products for in vitro antibacterial activity against ATCC® strains using the broth microdilution method. The compounds exhibited minimum inhibitory concentrations (MIC) of 1⁻32 μg/mL against Gram-positive ATCC® strains. The structure⁻activity relationship indicated that the thiophenol ring is essential for antibacterial activity and the substituents on the thiophenol ring module, for antibacterial activity. The most promising compounds detected by screening were tested against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREF) clinical isolates. We found remarkable activity against VREF for compounds 7 and 16, were the MIC50/90 were 2/4 µg/mL and 4/4 µg/mL, respectively, while for vancomycin the MIC50/90 was 256/512 µg/mL. Neither compound affected cell viability in any of the mammalian cell lines at any of the concentrations tested. These in vitro data show that compounds 7 and 16 have an interesting potential to be developed as new antibacterial drugs against infections caused by VREF.https://www.mdpi.com/1420-3049/23/7/177
Alternative protein sources in the diet modulate microbiota and functionality in the distal intestine of Atlantic salmon ( Salmo salar )
Environmental plasticity and colonisation history in the Atlantic salmon microbiome: A translocation experiment
Исследователь в современном междисциплинарном пространстве: возможности изучения образов и пространства города советской эпохи
Estigma hacia la demencia: una revisión
Dementia, known asmajor neurocognitive disorder on DSM V, is a public health priority due to its increasing prevalence and individual and social consequences. Stigma is a social exclusion and devaluation, as a result of negative perceptions towardsa persons' attribute or behavior. It is considered as a collective phenomenon related to this condition, as it impacts quality of life of people with dementia and their family environments. Among other consequences, stigma becomes a barrier to timely access to diagnosis, treatment and comprehensive support. The main purpose of this review is to describe and to analyze the phenomenon of stigma related to dementia as an emerging issue for Latin America. Stigma towards dementia can be classified as follows: public stigma (members of the community), professional and structural stigma (institutions, public policy, healthcare professionals, etc.), stigma in people with dementia know as self-stigma, and family stigma (carers, family environment). For each of these groups stigma is developed withspecific characteristics andconsequences. Stigma is an important component of dementia strategies involvingdiagnosis, treatment and promotion of social integration for people with dementia and requires an integrated approach from ethical, social and health perspectives
Degeneracy in the neurological model of auditory speech repetition
Both classic and contemporary models of auditory word repetition involve at least four left hemisphere regions: primary auditory cortex for processing sounds; pSTS (within Wernicke's area) for processing auditory images of speech; pOp (within Broca's area) for processing motor images of speech; and primary motor cortex for overt speech articulation. Previous functional-MRI (fMRI) studies confirm that auditory repetition activates these regions, in addition to many others. Crucially, however, contemporary models do not specify how regions interact and drive each other during auditory repetition. Here, we used dynamic causal modelling, to test the functional interplay among the four core brain regions during single auditory word and pseudoword repetition. Our analysis is grounded in the principle of degeneracy-i.e., many-to-one structure-function relationships-where multiple neural pathways can execute the same function. Contrary to expectation, we found that, for both word and pseudoword repetition, (i) the effective connectivity between pSTS and pOp was predominantly bidirectional and inhibitory; (ii) activity in the motor cortex could be driven by either pSTS or pOp; and (iii) the latter varied both within and between individuals. These results suggest that different neural pathways can support auditory speech repetition. This degeneracy may explain resilience to functional loss after brain damage
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