Revista del Hospital Italiano de Buenos Aires, 2021
Este será el primero de dos artículos donde se tratarán los pasos necesarios para desarrollar un ... more Este será el primero de dos artículos donde se tratarán los pasos necesarios para desarrollar un proyecto de aplicación de técnicas de Machine Learning en Salud, que introduce nociones sobre la recolección y análisis de datos, la selección y entrenamiento de modelos de aprendizaje automático de tipo supervisado y los métodos de validación interna para cada modelo.
Aloma: Revista de Psicologia, Ciències de l'Educació i de l'Esport
El uso de dispositivos digitales para tratar a personas con trastorno del espectro autista (TEA) ... more El uso de dispositivos digitales para tratar a personas con trastorno del espectro autista (TEA) tiene buena aceptación, pero hasta el momento no se han registrado investigaciones en Argentina que analicen empíricamente su aporte en cuanto a los comportamientos comunicativos. El objetivo de esta investigación consistió en evaluar la implicación de los dispositivos digitales por lo que respecta a dos parámetros conductuales: la postura y el foco atencional de niños con TEA. Para llevarlo a cabo se analizaron 211 sesiones (vídeos) de 11 niños (edad, Media = 6.45 años, DE = 1.30) durante la utilización de la aplicación AppTEA y dispositivos tradicionales en interacciones con profesionales, en el contexto de unas actividades terapéuticas. Como resultado se encontró que en las sesiones, los niveles y las tendencias de postura y el foco atencional fueron similares, independientemente de los dispositivos empleados. Por lo tanto, si bien las tecnologías y los softwares específicos pueden co...
Revista del Hospital Italiano de Buenos Aires, 2022
En el artículo anterior se introdujo el tema y se desarrolló cómo es la recolección y análisis de... more En el artículo anterior se introdujo el tema y se desarrolló cómo es la recolección y análisis de datos, la selección y entrenamiento de modelos de aprendizaje automático supervisados y los métodos de validación interna que permiten corroborar si el modelo arroja resultados similares a los de otros conjuntos de entrenamiento y de prueba. En este artículo continuaremos con la descripción de la evaluación del rendimiento, la selección del modelo más adecuado para identificar la característica que se va a evaluar y la validación externa del modelo. Además, el artículo resume los desafíos existentes en la implementación del Machine Learning desde la investigación al uso clínico.
Plasma and stool metabolomics to identify microbiota derived-biomarkers of metabolic dysfunction-associated fatty liver disease: effect of PNPLA3 genotype
Metabolomics, 2021
INTRODUCTION Non-invasive biomarkers are needed for metabolic dysfunction-associated fatty liver ... more INTRODUCTION Non-invasive biomarkers are needed for metabolic dysfunction-associated fatty liver disease (MAFLD), especially for patients at risk of disease progression in high-prevalence areas. The microbiota and its metabolites represent a niche for MAFLD biomarker discovery. However, studies are not reproducible as the microbiota is variable. OBJECTIVES We aimed to identify microbiota-derived metabolomic biomarkers that may contribute to the higher MAFLD prevalence and different disease severity in Latin America, where data is scarce. METHODS We compared the plasma and stool metabolomes, gene patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 single nucleotide polymorphism (SNP), diet, demographic and clinical data of 33 patients (12 simple steatosis and 21 steatohepatitis) and 19 healthy volunteers (HV). The potential predictive utility of the identified biomarkers for MAFLD diagnosis and progression was evaluated by logistic regression modelling and ROC curves. RESULTS Twenty-four (22 in plasma and 2 in stool) out of 424 metabolites differed among groups. Plasma triglyceride (TG) levels were higher among MAFLD patients, whereas plasma phosphatidylcholine (PC) and lysoPC levels were lower among HV. The PNPLA3 risk genotype was related to higher plasma levels of eicosenoic acid or fatty acid 20:1 (FA(20:1)). Body mass index and plasma levels of PCaaC24:0, FA(20:1) and TG (16:1_34:1) showed the best AUROC for MAFLD diagnosis, whereas steatosis and steatohepatitis could be discriminated with plasma levels of PCaaC24:0 and PCaeC40:1. CONCLUSION This study identified for the first time MAFLD potential non-invasive biomarkers in a Latin American population. The association of PNPLA3 genotype with FA(20:1) suggests a novel metabolic pathway influencing MAFLD pathogenesis.
Con amor y agradecimiento A mi familia y a la Sanmarquinidad "Amar y conocer la universidad para ... more Con amor y agradecimiento A mi familia y a la Sanmarquinidad "Amar y conocer la universidad para transformarla" (1551-2016) iii INDICE Pág. RESUMEN ix CONCLUSIONES xii ABSTRACT xiii CONCLUSIONS xv 1. INTRODUCCIÓN 1 2. SITUACIÓN PROBLEMÁTICA 5 3. FORMULACIÓN DEL PROBLEMA 6 4. OBJETIVOS 10 5. JUSTIFICACIÓN DEL PROBLEMA 11 6. MARCO TEÓRICO 12 7. ANTECEDENTES 12 A. LA COSMOLOGÍA PRIMITIVA 12 B. EL LENGUAJE METAFÓRICO 17 C. LA ABSTRACCIÓN. 19 D. LIMITACIONES DE LA INVESTIGACION. 20 8. BASES TEORICAS DE LA INVESTIGACION 21 9. HIPOTESIS 23 10. METODOLOGÍA 24 11. PROCEDIMIENTOS 25 12. DISCUSIÓN Y RESULTADOS 26 PARTE I-EL EPISTEME 26 A. DE LA CIENCIA 28 viii CdroNº8 Los planetas del sistema solar según diámetro, masa, radar, periodo, órbita, rotación y satélites.
ABSTRACTBackground and AimsNon-invasive biomarkers are urgently needed to identify patients with ... more ABSTRACTBackground and AimsNon-invasive biomarkers are urgently needed to identify patients with non-alcoholic fatty liver disease (NAFLD) especially those at risk of disease progression. This is particularly true in high prevalence areas such as Latin America. The gut microbiome and intestinal permeability may play a role in the risk of developing NAFLD and NASH, but the mechanism by which microbiota composition disruption (or dysbiosis) may affect NAFLD progression is still unknown. Targeted metabolomics is a powerful technology for discovering new associations between gut microbiome-derived metabolites and disease. Thus, we aimed to identify potential metabolomic biomarkers related to the NAFLD stage in Argentina, and to assess their relationship with clinical and host genetic factors.Materials and methodsAdult healthy volunteers (HV) and biopsy-proven simple steatosis (SS) or non-alcoholic steatohepatitis (NASH) patients were recruited. Demographic, clinical and food frequency c...
Communications in Nonlinear Science and Numerical Simulation, 2019
Intracranial Pressure (ICP) is one of the main neuromonitories used today to guide the treatment ... more Intracranial Pressure (ICP) is one of the main neuromonitories used today to guide the treatment of acute neurological patients in the Intensive Care Unit (ICU). Within this article the complexity of periods of intracranial hypertension is evaluated and compared with periods of stable intracranial tension. Using the multiparameter intelligent monitoring in intensive care III (MIMIC-III) database from the Beth Israel Deaconess Medical Center the complexity of periods of stable intracranial tension and high intracranial hypertension are evaluated using two quantifiers: the Permutation Entropy and their respective number of missing patterns. Both indicate a loss of complexity in hypertension signals. A physiological explanation of this loss of complexity is given using a dynamical model of the Cerebral Autorregulation and Cerebral Hemodynamics.
Emergencias 69 5.2.-Adquisición de bienes inmuebles 5.3.-Arrendamiento de bienes inmuebles 74 5.4... more Emergencias 69 5.2.-Adquisición de bienes inmuebles 5.3.-Arrendamiento de bienes inmuebles 74 5.4.-Contratos regidos por Normas Especiales 75
Summary At AECL – Chalk River Laboratories, Ontario, Canada solid, low-level radioactive wastes f... more Summary At AECL – Chalk River Laboratories, Ontario, Canada solid, low-level radioactive wastes from industrial, academic and medical applications have been stored in trenches above unconsolidated sandy glacial tills and permeable very-fine to fine-grained sands overlying crystalline bedrock. The sandy aquifer system drains into a swamp comprised of approximately 3 m of sphagnum peat. A comprehensive field and analytical program, involving measurements of total iodine, 129I, tritium, 14C and 13C/12C ratios in groundwater and geologic materials (sands and peats), was initiated at this site to examine the partitioning of 127I and 129I amongst the various reservoirs in this system and the controlling factors. The maximum iodine concentration and 129I inside the groundwater contaminant plume at the recharge and discharge sites were 67.0 ng/ml and ∼8.3 × 1011 atoms/liter, and 32.4 ng/ml and ∼2.9 × 1011 atoms/liter, respectively, with positive correlations between iodine, 14C (0.82), and ...
In order to study the role of polysaccharides in the cycling of marine organic matter and transpa... more In order to study the role of polysaccharides in the cycling of marine organic matter and transparent exopolymeric particles (TEP), the concentrations of total carbohydrates (p-TCHO), total uronic acids (URA) and total acid polysaccharides (APS) in suspended and sinking particles, as well as carbohydrates in the filter-passing ''dissolved'' phase (d-TCHO), were measured in vertical profiles along a N-S transect in the Gulf of Mexico, across a cold core (CCR) and a warm core (WCR) ring (eddy) during both July 2000 and May 2001. The concentrations of d-TCHO in 2000 ranged from 4 to 22 AM C, with a subsurface maximum, which was located slightly above the depth of chl a maximum, amounting to, on average, 34% of DOC in the CCR, and 13% in the WCR. The concentration of particulate carbohydrates (p-TCHO) in different size fractions (0.7-10, 10-53, and >53 Am) ranged from 0.04 to 1.1, 0.005 to 0.40, and 0.006 to 0.26 AM C, respectively, indicating that carbohydrates are mostly concentrated in small particles (0.7-10 Am). URA and APS were similarly concentrated in small particles, in which, on average, URA accounted for 87% and 57% of total URA, and APS for 92% and 88% of total APS in 2000 and 2001, respectively. URA accounted for 3-9% of carbohydrates in suspended particles, suggesting that URA are a minor component of the p-TCHO pool. Due to its surface-reactive nature, URA could play a major role in the coagulation of particles and macromolecules despite its relatively low abundance. While, on average, p-TCHO and total APS were more enriched in suspended particles than in sinking particles in both 2000 and 2001, the opposite was true for URA in both years. The greater contents of URA that are present in settling particles compared to suspended particles could indicate a mass flow in the direction of sinking particles, either caused by coagulation, by bacterial reworking of particulate and colloidal organic matter, or by their more refractory nature.
Th(IV) isotopes are important proxies in oceanographic investigations, and are used as tracers of... more Th(IV) isotopes are important proxies in oceanographic investigations, and are used as tracers of particle dynamics and particulate organic matter (POC) fluxes out of the euphotic zone through the use of 234 Th/POC ratios. These approaches rely on empirically determined and variable POC to 234 Th ratios, which might be controlled, in parts, by the abundance of exopolymeric substances (EPS). EPS contain acidic polysaccharides (APS) and are excreted by both phytoplankton and bacteria. To this end, radiotracer experiments with EPS from microbial cultures were conducted to determine the binding environment of 234 Th(IV)-binding ligands in colloids and suspended particles in marine systems. In these experiments, the 234 Th distribution during isoelectric focusing (IEF) and polyacrylamide gel electrophoresis (PAGE) was related to the functional group composition of EPS and of colloidal organic matter (COM) isolated from the Gulf of Mexico (GOM) using cross-flow ultrafiltration. EPS was extracted from phytoplankton (Emiliania huxleyi and Synechococcus elongatus) and bacteria (Sagittula stellata and Roseobacter gallaeciensis) cultures by repeated alcohol precipitation. Phosphate and sulfate concentrations were determined using ion chromatography (IC). IEF profiles indicated that 49% to 65% of the 234 Th labeled EPS from plankton and bacteria as well as COM samples from the GOM was found concentrated below pH of 4, near an isoelectric point, pH IEF , of about 2. The carboxylic acid maxima for extracted EPS and COM samples appeared close to the pH IEF of 234 Th(IV). The phosphate maximum appeared at the same pH IEF as 234 Th(IV) for EPS from Roseobacter gallaeciensis and Synechococcus elongatus. The sulfate maximum was found at the same pH IEF as 234 Th(IV) for EPS from S. elongatus and COM. The molecular weight (MW) of the strongly Th(IV) binding ligand varied from 1-14 kDa, depending on the species, but was about 10 kDa in COM. Thus, depending on the species of plankton or bacteria, the MW and specific functional group composition of the strongly 234 Th(IV)-binding amphiphilic biomolecule can vary. Therefore, different acidic functional groups can, at times, contribute to the binding of Th(IV) to the EPS chelating ligand, which can also have different MWs. This implies that the binding environment for Th(IV), which is present at total concentrations at least a million times lower than the acid functional groups, consists of strong polydentate chelate complexes in clustered structures of carboxylate, sulfates and/or phosphates. The combination of strongly chelating groups and amphiphilicity gives this biomolecule the unique properties of a "sticky" ligand.
Recent discoveries reveal that polymer gel particles are abundant and important in the microbial ... more Recent discoveries reveal that polymer gel particles are abundant and important in the microbial loop, sedimentation processes, biogeochemical cycling, marine carbohydrate chemistry, and particle dynamics in the ocean. The novelty of these discoveries elicited an interdisciplinary discussion among investigators working in marine geochemistry, microbiology, and polymer physics on the significance of gels in the functioning of marine ecosystems. Marine gels are three-dimensional networks of biopolymers imbedded in seawater. They range in size from single macromolecules entwined, forming single-chain colloidal networks, to assembled polymer networks several hundreds of microns or larger. Gels can form in minutes to hours from dissolved organic matter or polymer chains released by phytoplankton or bacteria. They enclose nanoscale microenvironments that exhibit emerging physical, chemical, and biological properties that are drastically different from those of the DOM polymers that make them. Previous studies show that~10% of surface DOM could be assembled as gels, yielding estimates of~70Â10 15 g of organic carbon. This figure exceeds the global biomass of marine organisms by a factor of 50. The potential huge magnitude of the oceanic gel organic matter (GOM) pool suggests a need to develop reliable quantitative methods to systematically investigate the budget of marine gels and their role in biogeochemical cycling. Gels are particularly important for carbon cycling in that they provide an abiotic mechanism to move organic molecules up the particle size spectrum to sizes capable of sedimentation and eventual sequestration in the deep sea. Macrogels such as transparent exopolymer particles (TEP) are especially significant in sedimentation processes because they appear to be critical for the formation of marine snow and the aggregation of diatom blooms. The discovery of highly abundant gels in seawater also fundamentally changes how we think about the physical nature and microscale structure of the fluid and organic matter field encountered by bacteria, protists, and viruses in the sea. Gels may serve as nutrients and/or attachment surfaces for microbes, as refuges from predation, and as hot spots of high substrate concentration.
Este documento contiene una revision sobre los principales simuladores de red y la importancia de... more Este documento contiene una revision sobre los principales simuladores de red y la importancia de estos para los procesos de investigacion y desarrollo de las telecomunicaciones asi como de la efectividad de los mismos para recrear de manera suficientemente aproximada los procesos que se realizan en las redes reales ya que con el uso de estas herramientas se estan analizando y probando los nuevos protocolos de red, siendo de gran importancia poder contar con resultados confiables generados a partir de procesos de simulacion.
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