La conservacion de instrumentos publicos, notariales y registrales

78 p.En este trabajo se ha querido mostrar cual es el sistema que se utiliza en nuestro país para la conservacion de instrumentos públicos, la forma de demostrarlo fue a través de una recopilación de información relativa a los métodos de conservacion de archivos, específicamente en todo lo que se refiere al espacio físico donde se conservan los documentos, los controles de humedad, de Iuz, de plagas. Así también, me enfoque en realizar una serie de entrevistas a funcionarios públicos, con el objeto de dar a conocer si se cumplen o no con las normas básicas de conservacion, así Como con las disposiciones legales que se establecen al respecto

Investigating the contribution of the right hemisphere to language processing in the damaged and healthy brain

Acquired language disorders after stroke are strongly associated with left hemisphere damage. When language difficulties are observed after right hemisphere damage, patients are commonly considered to have atypical functional anatomy (i.e. crossed aphasia). On the other hand, fMRI studies have reported right hemisphere activation when neurologically-normal participants perform language tasks, and have shown that the right hemisphere contributes to recovery of language function after left hemisphere damage. In this thesis I investigated (i) the degree to which language difficulties after right hemisphere stroke can reflect disruption to typical functional anatomy and (ii) how the damaged areas contribute to normal language processing. In Study 1 (Chapter 3), I investigated a group of patients with unilateral strokes that damaged either the right or the left hemisphere. The most frequently impaired language task was auditory sentence-to-picture matching after right hemisphere strokes, and spoken picture description after left hemisphere strokes. In 9 right hemisphere stroke patients, performance on the auditory sentence-to-picture matching task was selectively impaired and could not be explained by poor perceptual (visual or auditory) or linguistic processing (semantic, phonological or syntactic). I therefore hypothesised that the behavioural difficulties experienced by those patients arose as a consequence of impaired non-linguistic executive functions that are needed to support language processes. In Study 2 (Chapter 4), I investigated the lesions of the 9 patients with selective deficits in the auditory sentence-to-picture matching task, and found that they had significantly more damage to subcortical regions and parts of the superior longitudinal fasciculus impinging on the right inferior frontal sulcus compared to other right hemisphere stroke patients who were not impaired on the sentence comprehension task. Having identified these regions, their function (e.g. linguistic or executive) can be investigated using functional neuroimaging in neurologically-normal participants. In Study 3 (Chapter 5), I used fMRI to investigate whether any parts of the right hemisphere regions associated with impaired sentence comprehension, in Study 2, were activated when neurologically-normal participants performed similar language tasks to those administered to right hemisphere stroke patients in Study 1 (including the auditory sentence-to-picture matching task). I found that, within the brain areas derived from Study 2, the right inferior frontal sulcus and right mediodorsal thalamus were normally activated by auditory sentence-to-picture matching but there was no evidence that these regions were exclusively performing linguistic functions. In Study 4 (Chapter 6), I investigated the contribution of the identified regions further by using a new fMRI study of one-back matching tasks that varied demands on semantic and non-semantic working memory. By systematically integrating neuropsychological, lesion and fMRI data, I conclude that the right inferior frontal cortex and right mediodorsal thalamus contribute to non-semantic working memory capacity that is needed to accurately perform a range of language functions. This account helps to explain why auditory sentence-to-picture matching impairments occur after right hemisphere damage

Prevalencia de Entamoeba gingivalis en pacientes con enfermedad periodontal cronica

44 p.Hace años se ha descrito el posible papel que tendría E. gingivalis en la patogenia de la enfermedad periodontal y de otras afecciones estomatológicas como: caries dentales, periodontopatías, pulpitis, gangrenas, estomatitis ulcero-necrótica, entre otras. En Chile no se han reportado casos o estudios que den cuenta de la prevalencia de este protozoo, por lo tanto, el propósito central de este trabajo es conocer la prevalencia de Entamoeba gingivalis en pacientes con enfermedad periodontal que asistieron al Hospital Regional de Talca, Consultorio Dionisio Astaburuaga y Centro de Salud Familiar Carlos Trupp (CESFAM) entre el periodo marzo-mayo de 2009. Para la identificación de E. gingivalis la metodología utilizada fue, la obtención de muestras de líquido crevicular tomadas desde sacos periodontales activos y de placa y/o cálculo dental a 96 pacientes de ambos sexos. A cada una de las muestras obtenidas se les realizó un examen directo y cultivo. Los resultados obtenidos de este estudio arrojaron que existe una prevalencia de Entamoeba gingivalis de 16,7%; además se determinó que existía asociación entre la presencia de Entamoeba gingivalis y las variables sexo y severidad de la Enfermedad Periodontal

Paradoxical lesions, plasticity and active inference

Paradoxical lesions are secondary brain lesions that ameliorate functional deficits caused by the initial insult. This effect has been explained in several ways; particularly by the reduction of functional inhibition, or by increases in the excitatory-to-inhibitory synaptic balance within perilesional tissue. In this article, we simulate how and when a modification of the excitatory–inhibitory balance triggers the reversal of a functional deficit caused by a primary lesion. For this, we introduce in-silico lesions to an active inference model of auditory word repetition. The first in-silico lesion simulated damage to the extrinsic (between regions) connectivity causing a functional deficit that did not fully resolve over 100 trials of a word repetition task. The second lesion was implemented in the intrinsic (within region) connectivity, compromising the model’s ability to rebalance excitatory–inhibitory connections during learning. We found that when the second lesion was mild, there was an increase in experience-dependent plasticity that enhanced performance relative to a single lesion. This paradoxical lesion effect disappeared when the second lesion was more severe because plasticity-related changes were disproportionately amplified in the intrinsic connectivity, relative to lesioned extrinsic connections. Finally, this framework was used to predict the physiological correlates of paradoxical lesions. This formal approach provides new insights into the computational and neurophysiological mechanisms that allow some patients to recover after large or multiple lesions

Prevalencia y severidad de MH y dmh por año de nacimiento en niños de 5 y 14 años en la provincia de Talca, 2017

90 p.Introducción: La Hipomineralización molar corresponde a un defecto del esmalte altamente prevalente, objeto de múltiples investigaciones alrededor del mundo debido a las diversas complicaciones asociadas. En la actualidad aún no se ha podido determinar su etiología específica, sin embargo se sugieren diferentes eventos y condiciones nocivas (ejemplo, enfermedades de la infancia). Por esta razón que se hace necesario analizar las variaciones epidemiológicas de MH/DMH por año de nacimiento, con el objeto obtener pistas que se relacionen a la causa de esta condición y permitan desarrollar nuevas investigaciones que contribuyan a su control y, finalmente, su prevención. Objetivo general: Determinar la presencia y severidad del MH y DMH en niños de 5 a 14 años, según año de nacimiento, en la provincia de Talca, Región del Maule, Chile, entre los años 2001 y 2010. Metodología: Estudio descriptivo de corte transversal. Universo comprendido por niños entre 5 a 14 años, matriculados en kínder, tercero y octavo básico de establecimientos educacionales de dependencia municipal, con aportes de fluoruros, pertenecientes a las 7 comunas de la provincia de Talca. El tamaño muestra lo obtenido fue de 1195 niños. Para el diagnóstico de MH/DMH se utilizó clasificación de DDE modificado (FDI, 1992) y el criterio diagnóstico de 3 examinadores calibrados (coeficiente kappa >0.9 intra e interexaminador). El estudio fue aprobado por el comité de ética de la Universidad de Talca. Se obtuvo la autorización de los Directores de los diferentes establecimientos, de los padres mediante consentimiento informado y asentimiento de los menores. Se realizó el examen visual, respetando las medidas universales de control de infecciones recomendadas por la OMS. Resultados: Se examinaron 1195 niños. La prevalencia general de MH fue de un 29% (n=344), de los cuales el 51% (n=177) corresponden a hombres, sin asociación significativa (p=0,029). Prevalencia de MH varía según el año de nacimiento, existiendo asociación significativa (p<0,005). El nacer durante el año 2007 es un factor de riesgo para desarrollar MH (OR=2,017); mientras que haber nacido el año 2010 corresponde a un factor protector en relación al MH (OR=0,190). El MH leve fue el más prevalente con un 69% (n=237), de los cuales el 51% corresponden a hombres. No hay asociación entre la severidad del MH y el sexo de los niños (p=0,014). En todos los años el MH leve es el más prevalente, sin existir asociación entre la severidad del MH y el año de nacimiento del niño (p=0,089). La prevalencia general de DMH fue de un 14% (n=170), el 50% de ellos (n=85) corresponden a mujeres, sin presentar asociación significativa (p=0,165). Prevalencia de DMH varía según año de nacimiento, valores van desde un 1% (n=3) en el año 2002 y un 27% (n=23) el año 2009, presentando asociación significativa entre la presencia de DMH y el año de nacimiento (p<0,005). Nacer dentro de los años 2009 y 2010 representan un factor de riesgo para el desarrollo de DMH (OR=2,203; 1,993 respectivamente). DMH severo es el más prevalente, representado por el 53% (n=90), de los cuales el 51% son hombres, sin asociación significativa por sexo (p=0,165). Los años 2006 y 2007 son los que presentan un porcentaje más elevado de DMH severo, con un 64% y 61% respectivamente, pero sin diferencias estadísticamente significativas (p=0,020). Existe asociación entre la presencia de DMH y la presencia de MH en un mismo niño (p< 0,005), determinando que la presencia de DMH es un factor de riesgo para el desarrollo de MH (OR=3,160). También existe asociación positiva entre la severidad del DMH y la del MH (p = 0,003). No existe asociación entre una mayor severidad del DMH y una mayor presencia de MH (p= 0,141). Conclusión: Existe una alta prevalencia de MH/DMH la cual es variable y asociada significativamente al año de nacimiento. La prevalencia de MH es mayor que la del DMH. Sin embargo, el DMH presenta casos más severos Existen factores de riesgo para desarrollar MH, como el haber nacido el año 2007 y también el de presentar DMH y el año 2010 parece ser un factor protector de MH. Nacer en los años 2007, 2009 y 2010 constituye un factor de riesgo en el caso del DMH. DMH severo se asocia significativamente al MH severo, pero no a una mayor prevalencia de MH. /ABSTRACT: Introduction: Molar Hypomineralization corresponds to a highly prevalent enamel defect and is focus of multiple investigations around the world due to the various associated complications. At present, it has not yet been possible to determine its specific etiology; however different events and harmful conditions are suggested (for example, childhood diseases). For this reason it is necessary to analyze the epidemiological variations of MH / DMH by the year of birth, in order to obtain clues that can be related to the cause of this condition. Moreover, this will allow the development of new researchs that may contribute to the main goal of preventing this condition. General objective: To determine the prevalence and severity of MH and DMH in children from 5 to 14 years old, according to the year of birth, in the province of Talca, Maule Region, Chile, between 2001 and 2010. Methodology: A cross-sectional study was undertaken. The universe was comprised by children between 5 to 14 years old, enrolled in indergarten, from third and eighth grade of educational establishments of municipal dependency, with contributions of fluorides, belonging to the 7 communes of the province of Talca. The sample size calculation was 1269 children, considering a loss of 10%. For the diagnosis of MH / DMH, a modified DDE classification was used (FDI, 1992) and the diagnostic criterion of 3 calibrated examiners (kappa coefficient> 0.9 intra and inter-examiner). The study was approved by the ethics committee of the University of Talca. The authorization of the Directors of the different stablishments, of the parents was obtained through informed consent and assent of the minors. The visual examination was carried out, respecting the universal infection control measures recommended by the WHO. Results: 1195 children were examined. The general prevalence of MH was 29% (n = 344), of which 51% (n = 177) were male, without significant association (p = 0.029). Prevalence of MH varies significantly according to the year of birth, (p <0.005). Being born during 2007 is a risk factor for developing MH (OR = 2.017); while having been born in 2010 corresponds to a protective factor (OR = 0.190). Mild MH was the most prevalent with 69% (n = 237), of which 51% were male. There is no association between the severity of MH and the sex of the children (p = 0.014). In all studied years, the mild MH is the most prevalent, without an association between the severity of MH and the year of birth (p = 0.089). The general prevalence of DMH was 14% (n = 170), 50% of them (n = 85) corresponded to women, without presenting significant association (p = 0.165). Prevalence of DMH varies according to year of birth, values range from 1% (n = 3) in 2002 and 27% (n = 23) in 2009, presenting a significant association between the presence of DMH and the year of birth (p <0.005). Being born in 2009 and 2010 represent a risk factor for the development of DMH (OR = 2,203, 1,993 respectively). Severe DMH is the most prevalent, represented by 53% (n = 90), of which 51% are men, without significant association by sex (p = 0.165). The years 2006 and 2007 are those that present a higher percentage of severe DMH, with 64% and 61% respectively, but without statistically significant differences (p = 0.020). There is an association between the presence of DMH and the presence of MH in the same child (p <0.005). The presence of DMH is a risk factor to develop MH (OR = 3.160). There is also a positive association between the severity of DMH and that of MH (p = 0.003). There is no association between a higher severity of DMH and a greater presence of MH (p = 0.141). Conclusion: There is a high prevalence of MH / DMH which is variable and significantly associated with the year of birth. The prevalence of MH is greater than that of DMH. However, the DMH presents more severe cases There are risk factors to develop MH, such as having been born in 2007 and also that of presenting DMH and 2010 seems to be a protective factor of MH. Being born in the years 2007, 2009 and 2010 constitutes a risk factor in the case of DMH. Severe DMH is significantly associated with severe MH, but not with a higher MH prevalence

Trend in vegetational cover affected by fire in the Torres del Paine National Park

[EN] Torres del Paine National Park (PNTP) is characterized as a representative geographical area of the world’s ecosystems, containing high scenic beauty and wide variety of ecosystems. The aim of this work is to analyze the spatial and temporal trends of vegetation at PNTP using remote images from the Landsat platforms, the MOD13A3 product from the Moderate Resolution Imaging Spectroradiometer (MODIS), coverage maps surface Global Land cover Maps of ESA/CCI 2005 and 2010 and a land cover map of continental Chile of 2014. In addition, the products of Soil Moisture and Ocean Salinity (SMOS) and meteorological data from the Torres del Paine meteorological station were used to analyze the environmental conditions that presented the park while the fire occurred the years 2011-2012. To determine the magni­tude of the changes of vegetation affected by fire at PNTP a nonparametric trend analysis was use with the Normalized Difference Vegetation Index (NDVI) of MODIS from 2002 to 2016 and the Normalized Burn Ratio (NBR) for the fire occurred the year 2005 and the years 2011-2012. The results show that between both fires it is been affected more than 30.000 hectares of the national park, being the “Scrub” and “Forest” coverage the most affected due to the high level of severity and the low regeneration of the burn area (less than 56%). The soil moisture does not exceed 20% m3m-3 before the fire and the rainfall does not exceed 101 mm during the days of fire, which is related to an increase in the probability of propa­gation of the fire. In this work is possible to realize that remote sensing can be used in the fire management to regard the national parks with the objective of preserve and conserve the flora, fauna and scenic beauty of Chile.[ES] El Parque Nacional Torres del Paine (PNTP) se caracteriza por ser un área geográfica representativa de los ecosistemas del mundo, al contener una alta belleza paisajística y amplia diversidad de ecosistemas. El objetivo de este trabajo es analizar las tendencias espacio temporales de la vegetación en el PNTP mediante el uso de imágenes remo­tas de la plataforma Landsat, del sensor “Moderate Resolution Imaging Spectroradiometer” (MODIS), correspondientes al producto MOD13A3, los mapas de cobertura de superficie Global Land Cover Maps del ESA/CCI del año 2005 y 2010 y el mapa de cobertura de suelo de Chile continental del 2014. Además, se utilizaron los productos de “Soil Moisture and Ocean Salinity” (SMOS), y datos meteorológicos de la estación meteorológica Torres del Paine para analizar las condiciones ambientales que presentó el parque mientras ocurría el incendio de los años 2011-2012. Para determinar la magnitud de los cambios de la vegetación afectada por incendio del PNTP se realizó un análisis no paramétrico de la tendencia del índice “Normalized Difference Vegetacion Index” (NDVI) de MODIS en el periodo 2002 a 2016 y el índice “Normalized Burn Ratio” (NBR) para los incendios de los años 2005 y 2011-2012. Los resultados muestran que los incendios 2005 y 2011-2012 afectaron a más de 30.000 hectáreas del Parque Nacional, siendo las coberturas de “Matorral” y “Bosque” las más afectadas debido a su alto nivel de severidad y su regeneración menor al 56% de la superficie afectada. En cuanto a la humedad de suelo esta no supera los 20% m3m–3 antes del incendio y las precipitaciones no superan los 101 mm durante los días de incendio lo que se relaciona con un aumento en las probabilidades de propagación del incendio. En este trabajo se evidencia que la teledetección puede ser utilizada en la gestión de incendios y así resguardar los parques nacionales con el fin de preservar y conservar la flora, fauna y belleza paisajística de Chile.Gracias al proyecto Conicyt – Fondecyt Iniciación 11130359 “Estimating the Surface soil moisture at regional scale by using a synergic optical-passive microwave approach and remote sensing data”, a United States Geological Survery (USGS) por el libre acceso a los datos Landsat-5 TM, Landsat-7 ETM+ y Landsat-8 OLI, a la National Aeronautics and Space (NASA) por los productos MODIS y la Dra. María Piles por los productos de humedad de suelo SMOS.Rivera, C.; Mattar, C.; Durán-Alarcón, C. (2017). Tendencia de la cobertura vegetacional afectada por incendios en el Parque Nacional Torres del Paine. Revista de Teledetección. (50):71-87. https://doi.org/10.4995/raet.2017.7422SWORD71875

A functional dissociation of the left frontal regions that contribute to single word production tasks

Controversy surrounds the interpretation of higher activation for pseudoword compared to word reading in the left precentral gyrus and pars opercularis. Specifically, does activation in these regions reflect: (1) the demands on sublexical assembly of articulatory codes, or (2) retrieval effort because the combinations of articulatory codes are unfamiliar? Using fMRI, in 84 neurologically intact participants, we addressed this issue by comparing reading and repetition of words (W) and pseudowords (P) to naming objects (O) from pictures or sounds. As objects do not provide sublexical articulatory cues, we hypothesis that retrieval effort will be greater for object naming than word repetition/reading (which benefits from both lexical and sublexical cues); while the demands on sublexical assembly will be higher for pseudoword production than object naming. We found that activation was: (i) highest for pseudoword reading [P>O&W in the visual modality] in the anterior part of the ventral precentral gyrus bordering the precentral sulcus (vPCg/vPCs), consistent with the sublexical assembly of articulatory codes; but (ii) as high for object naming as pseudoword production [P&O>W] in dorsal precentral gyrus (dPCg) and the left inferior frontal junction (IFJ), consistent with retrieval demands and cognitive control. In addition, we dissociate the response properties of vPCg/vPCs, dPCg and IFJ from other left frontal lobe regions that are activated during single word speech production. Specifically, in both auditory and visual modalities: a central part of vPCg (head and face area) was more activated for verbal than nonverbal stimuli [P&W>O]; and the pars orbitalis and inferior frontal sulcus were most activated during object naming [O>W&P]. Our findings help to resolve a previous discrepancy in the literature, dissociate three functionally distinct parts of the precentral gyrus, and refine our knowledge of the functional anatomy of speech production in the left frontal lobe

Dissociating the functions of three left posterior superior temporal regions that contribute to speech perception and production

Prior studies have shown that the left posterior superior temporal sulcus (pSTS) and left temporo-parietal junction (TPJ) both contribute to phonological short-term memory, speech perception and speech production. Here, by conducting a within-subjects multi-factorial fMRI study, we dissociate the response profiles of these regions and a third region - the anterior ascending terminal branch of the left superior temporal sulcus (atSTS), which lies dorsal to pSTS and ventral to TPJ. First, we show that each region was more activated by (i) 1-back matching on visually presented verbal stimuli (words or pseudowords) compared to 1-back matching on visually presented non-verbal stimuli (pictures of objects or non-objects), and (ii) overt speech production than 1-back matching, across 8 types of stimuli (visually presented words, pseudowords, objects and non-objects and aurally presented words, pseudowords, object sounds and meaningless hums). The response properties of the three regions dissociated within the auditory modality. In left TPJ, activation was higher for auditory stimuli that were non-verbal (sounds of objects or meaningless hums) compared to verbal (words and pseudowords), irrespective of task (speech production or 1-back matching). In left pSTS, activation was higher for non-semantic stimuli (pseudowords and hums) than semantic stimuli (words and object sounds) on the dorsal pSTS surface (dpSTS), irrespective of task. In left atSTS, activation was not sensitive to either semantic or verbal content. The contrasting response properties of left TPJ, dpSTS and atSTS was cross-validated in an independent sample of 59 participants, using region-by-condition interactions. We also show that each region participates in non-overlapping networks of frontal, parietal and cerebellar regions. Our results challenge previous claims about functional specialisation in the left posterior superior temporal lobe and motivate future studies to determine the timing and directionality of information flow in the brain networks involved in speech perception and production

Brain regions that support accurate speech production after damage to Broca's area

Broca's area in the posterior half of the left inferior frontal gyrus has traditionally been considered an important node in the speech production network. Nevertheless, recovery of speech production has been reported, to different degrees, within a few months of damage to Broca's area. Importantly, contemporary evidence suggests that, within Broca's area, its posterior part (i.e. pars opercularis) plays a more prominent role in speech production than its anterior part (i.e. pars triangularis). In this study, we therefore investigated the brain activation patterns that underlie accurate speech production following stroke damage to the opercular part of Broca's area. By combining functional MRI and 13 tasks that place varying demands on speech production, brain activation was compared in (i) seven patients of interest with damage to the opercular part of Broca's area; (ii) 55 neurologically intact controls; and (iii) 28 patient controls with left-hemisphere damage that spared Broca's area. When producing accurate overt speech responses, the patients with damage to the left pars opercularis activated a substantial portion of the normal bilaterally distributed system. Within this system, there was a lesion-site-dependent effect in a specific part of the right cerebellar Crus I where activation was significantly higher in the patients with damage to the left pars opercularis compared to both neurologically intact and patient controls. In addition, activation in the right pars opercularis was significantly higher in the patients with damage to the left pars opercularis relative to neurologically intact controls but not patient controls (after adjusting for differences in lesion size). By further examining how right Crus I and right pars opercularis responded across a range of conditions in the neurologically intact controls, we suggest that these regions play distinct roles in domain-general cognitive control. Finally, we show that enhanced activation in the right pars opercularis cannot be explained by release from an inhibitory relationship with the left pars opercularis (i.e. dis-inhibition) because right pars opercularis activation was positively related to left pars opercularis activation in neurologically intact controls. Our findings motivate and guide future studies to investigate (i) how exactly right Crus I and right pars opercularis support accurate speech production after damage to the opercular part of Broca's area and (ii) whether non-invasive neurostimulation to one or both of these regions boosts speech production recovery after damage to the opercular part of Broca's area