90 research outputs found
Classification Among Hidden Markov Models
An important task in AI is one of classifying an observation as belonging to one class among several (e.g. image classification). We revisit this problem in a verification context: given k partially observable systems modeled as Hidden Markov Models (also called labeled Markov chains), and an execution of one of them, can we eventually classify which system performed this execution, just by looking at its observations? Interestingly, this problem generalizes several problems in verification and control, such as fault diagnosis and opacity. Also, classification has strong connections with different notions of distances between stochastic models.
In this paper, we study a general and practical notion of classifiers, namely limit-sure classifiers, which allow misclassification, i.e. errors in classification, as long as the probability of misclassification tends to 0 as the length of the observation grows. To study the complexity of several notions of classification, we develop techniques based on a simple but powerful notion of stationary distributions for HMMs. We prove that one cannot classify among HMMs iff there is a finite separating word from their stationary distributions. This provides a direct proof that classifiability can be checked in PTIME, as an alternative to existing proofs using separating events (i.e. sets of infinite separating words) for the total variation distance. Our approach also allows us to introduce and tackle new notions of classifiability which are applicable in a security context
Criterios didácticos compartidos en la enseñanza de las estructuras en Arquitectura
Trabajo presentado en las 3º Jornadas de Estructuras en la Arquitectura, Mar del Plata 2013El presente trabajo expone la visión compartida de la temática estructural puesta en práctica en las asignaturas Estructuras I A, II A y III de la FAUD, UNC. Este enfoque responde a acuerdos y, principalmente, a la formación docente conjunta de quienes son responsables de los respectivos equipos de trabajo. El eje en que se desarrollan las tres asignaturas es la aplicación práctica de los conocimientos estructurales al proceso de diseño arquitectónico. Lo expresado requiere que en cada nivel, adecuado a las habilidades adquiridas, se incorporen planteos estructurales, su análisis, evaluación y reformulación sobre construcciones diseñadas por los alumnos y, en ocasiones, con obras seleccionadas en las que la resolución estructural reviste una importancia significativa. Para lograr la continuidad buscada en este proceso de enseñanza-aprendizaje se emplean en las tres asignaturas los mismos criterios, el mismo vocabulario y las mismas modalidades. Esto facilita al alumno a profundizar los conceptos y, permite, entre otras cosas, un rápido predimensionado con el fin de integrarlo al proceso de diseño sin constituir un capítulo separado. Para lograr el objetivo se pone a disposición de los alumnos una variedad de softwares, varios de ellos desarrollados por los integrantes de los equipos con fines didácticos, y presentados con códigos compartidos. Se estimula a través de una misma gráfica y esquemas a espacializar la estructura, relacionándola con las variables tecnológicas. También se realizan diversas experiencias con modelos, tendientes a facilitar la comprensión de distintos fenómenos. Los alumnos trabajan en taller practicando la ejecución a escala de elementos estructurales. Cabe destacar que la aplicación de estos conceptos en el desarrollo de los trabajos de los alumnos en las asignaturas de diseño es inducida por los miembros del equipo en una tarea de integración curricular con las cátedras de arquitectura. Se presentarán diversas prácticas y criterios usados durante el desarrollo de la currícula.Fil: Bonaiuti, Hugo. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Simonetti, Isolda. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Fabre, Raquel. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: González, Gustavo. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Elicabe, Alberto. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaIngeniería Arquitectónic
Metodología, herramientas y criterios de enseñanza de estructuras en Arquitectura
Trabajo presentado en el XXV Congreso Latinoamericano de Escuelas y Facultades de Arquitectura y Diseño. CLEFA 2014. Asunción del ParaguaySi bien no se puede hablar de una ?crisis? en el proceso de enseñanza-aprendizaje de las disciplinas de Estructuras en las facultades de Arquitectura, si se pueden reconocer ciertas dificultades que se manifiestan negativamente en la integración curricular, que el alumno debe realizar mientras desarrolla sus proyectos en las asignaturas de Diseño Arquitectónico. El presente trabajo expone la experiencia de visión compartida de la temática estructural puesta en práctica en las asignaturas Estructuras I A, II A, III de la FAUD, UNC. Este enfoque responde a acuerdos y, principalmente, a la formación docente conjunta de quienes son responsables de los respectivos equipos de trabajo. El eje en que se desarrollan las tres asignaturas es la aplicación práctica de los conocimientos estructurales al proceso de diseño arquitectónico. Lo expresado requiere que en cada nivel, adecuado a las habilidades adquiridas, se incorporen planteos estructurales, su análisis, evaluación y reformulación sobre construcciones diseñadas por los alumnos y, en ocasiones, con obras seleccionadas en las que la resolución estructural reviste una importancia significativa. Para lograr la continuidad buscada en este proceso de enseñanza-aprendizaje se emplean en las tres asignaturas los mismos criterios, el mismo vocabulario y las mismas modalidades. Esto facilita al alumno a profundizar los conceptos y, permite, entre otras cosas, un rápido predimensionado con el fin de integrarlo al proceso de diseño sin constituir un capítulo separado. Para lograr el objetivo se pone a disposición de los alumnos una variedad de softwares, varios de ellos desarrollados por los integrantes de los equipos con fines didácticos, y presentados con códigos compartidos. Se estimula a través de una misma gráfica y esquemas a espacializar la estructura, relacionándola con las variables tecnológicas. También se realizan diversas experiencias con modelos, tendientes a facilitar la comprensión de distintos fenómenos, los alumnos trabajan en taller practicando la ejecución a escala de elementos estructurales.Fil: Bonaiuti, Hugo Oscar. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Elicabe, Eduardo. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Fabre, Raquel. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Adler, Alicia. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Wuthrich, Eduardo. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaIngeniería Arquitectónic
Immunophenotyping Reveals the Diversity of Human Dental Pulp Mesenchymal Stromal Cells In vivo and Their Evolution upon In vitro Amplification
International audienceMesenchymal stromal/stem cells (MSCs) from human dental pulp (DP) can be expanded in vitro for cell-based and regenerative dentistry therapeutic purposes. However, their heterogeneity may be a hurdle to the achievement of reproducible and predictable therapeutic outcomes. To get a better knowledge about this heterogeneity, we designed a flow cytometric strategy to analyze the phenotype of DP cells in vivo and upon in vitro expansion with stem cell markers. We focused on the CD31 − cell population to exclude endothelial and leukocytic cells. Results showed that the in vivo CD31 − DP cell population contained 1.4% of CD56 + , 1.5% of CD146 + , 2.4% of CD271 + and 6.3% of MSCA-1 + cells but very few Stro-1 + cells (≤1%). CD56 + , CD146 + , CD271 + , and MSCA-1 + cell subpopulations expressed various levels of these markers. CD146 + MSCA-1 + , CD271 + MSCA-1 + , and CD146 + CD271 + cells were the most abundant DP-MSC populations. Analysis of DP-MSCs expanded in vitro with a medicinal manufacturing approach showed that CD146 was expressed by about 50% of CD56 + , CD271 + , MSCA-1 + , and Stro-1 + cells, and MSCA-1 by 15-30% of CD56 + , CD146 + , CD271 + , and Stro-1 + cells. These ratios remained stable with passages. CD271 and Stro-1 were expressed by <1% of the expanded cell populations. Interestingly, the percentage of CD56 + cells strongly increased from P1 (25%) to P4 (80%) both in all sub-populations studied. CD146 + CD56 + , MSCA-1 + CD56 + , and CD146 + MSCA-1 + cells were the most abundant DP-MSCs at the end of P4. These results established that DP-MSCs constitute a heterogeneous mixture of cells in pulp tissue in vivo and in culture, and that their phenotype is modified upon in vitro expansion. Further studies are needed to determine whether co-expression of specific MSC markers confers DP cells specific properties that could be used for the regeneration of human tissues, including the dental pulp, with standardized cell-based medicinal products
Assessing the age-related relationship between plasma anti-Müllerian Hormone (AMH) and ovarian follicle population in prepubertal ewes (abstract)
Publishe
patrimonio intelectual
Actas de congresoLas VI Jornadas se realizaron con la exposición de ponencias que se incluyeron en cuatro ejes temáticos, que se desarrollaron de modo sucesivo para facilitar la asistencia, el intercambio y el debate, distribuidos en tres jornadas.
Los ejes temáticos abordados fueron:
1. La enseñanza como proyecto de investigación. Recursos de enseñanza-aprendizaje como mejoras de la calidad educativa.
2. La experimentación como proyecto de investigación. Del ensayo a la aplicabilidad territorial, urbana, arquitectónica y de diseño industrial.
3. Tiempo y espacio como proyecto de investigación. Sentido, destino y usos del patrimonio construido y simbólico.
4. Idea constructiva, formulación y ejecución como proyecto de investigación. Búsqueda y elaboración de resultados que conforman los proyectos de la arquitectura y el diseño
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Ingénierie tissulaire du cartilage avec des cellules souches mésenchymateuses : développement d'une méthode de screening par cytométrie en flux pour caractériser diverses sources de cellules souches mésenchymateuses et évaluer la qualité de leur conversion chondrogénique
.Articular cartilage is made up of dense, connective tissue localized at the junction of several locations in the skeleton. It covers the surface of the joints to ensure that bones can move. It is an avascular tissue that is not innervated and is composed primarily of a single cell type, the chondrocyte, which synthesizes an abundant extracellular matrix (ECM). Osteoarthritis (OA), a degenerative disease of articular cartilage, is characterized by the degradation of the ECM, associated with increased secretion of matrix metalloproteinases (MMPs) and aggrecanases. In addition, the OA process induces chondrocyte dedifferentiation characterized at least in part by increased synthesis of type I collagen, an atypical isoform in articular cartilage. Moreover, due to the poor intrinsic healing capacity of articular cartilage, there is currently no treatment to restore the chondrocyte phenotype and, in the most advanced stages of OA, the joint must be replaced with a prosthesis, requiring surgery. Therefore, various drug and surgical treatments have been developed in an attempt to prevent the destruction of cartilage which, in light of their relative success, then lead to new, improved therapeutic strategies. One of the most promising approaches is the cartilage tissue engineering based on the procedure described by Brittberg using autologous chondrocyte implantation (ACI). Applied in the earliest stages of OA or chondral lesions, ACI is based on the use of chondrocytes from a healthy, non-bearing region of the diseased joint. The cells are then amplified in monolayer culture and then re-implanted in the lesion. However, amplification of autologous chondrocytes in two-dimensional culture mimics, at least in part, some of the characteristics of the OA process and is accompanied by cell dedifferentiation leading to the formation of nonfunctional fibrocartilage. The numerous pharmaceutical approaches and surgical techniques developed to repair cartilage lesions have revealed their limitations. Ideally, traumatic cartilage lesions should be treated earlier to prevent OA and postpone prosthetic surgery. In the interest of preventing OA, cartilage cell therapy has proven to be a pivotal approach for repairing damaged tissue. Cell therapy consists not only in filling the cartilage lesion with healthy chondrocytes, but also in reconstituting the structure, the physico-chemical properties and the functionality of the hyaline matrix. The transplantation of autologous chondrocytes is the foundation of cell therapy and cartilage tissue engineering and there have been several generations of ACI, each improving on the previous one. However, even the most recent ACI techniques are showing limitations and consequently, research efforts are now focused on improving this technique in order to obtain, after amplification, a differentiated and stable chondrocyte phenotype. This is to be achieved by using new types of biomaterials that can fill more important lesions, molecules and growth factors to better control the chondrogenic differentiation and more suitable cell sources that avoid morbidity at the donor site as it is the case with articular chondrocytes. Today, MSCs hold much promise for biomedical research because they are able to recapitulate many tissues, including cartilage. However, for future advances in the field of regeneration and tissue engineering it is important to know the exact nature of these cells. With this goal, in this work, we first fully characterized 4 categories of serum free amplified mesenchymal stem cells extracted from adipose tissue (AT), bone marrow (BM), dental pulp (DP) and Wharton’s jelly (WJ) of the umbilical cord. The cells were characterized in terms of efficiency of isolation, amplification kinetics and according to an extensive immunophenotyping using flow cytometry... [etc
Diagnosability Degree of Stochastic Discrete Event Systems
International audience— Diagnosability is the ability to detect a fault from partial observations collected on a system. It has been studied for numerous models of discrete event systems, but essentially from a logical perspective. This paper explores quantitative versions of the problem, to evaluate " how much " a system is (non-)diagnosable. For the diagnosable part of a system, that we characterize, we then examine the probability distribution of the detection delay. We show that the mean and the standard deviation of the detection delay can be easily evaluated
Complexity reduction techniques for quantified diagnosability of stochastic systems
International audienceIn a discrete event stochastic system, the natural notion of diagnosability, called A-diagnosability, requires that each fault event is eventually detected with probability one. Several definitions of diagnosability degree have been derived from this notion. They examine the detection probability after a fault occurs. To check diagnosability and compute diagnosability degrees, one usually attaches to the original stochastic system the information of a so-called diagnoser, which is in general exponentially larger than the original system. In this paper, we show that the full complexity of such diagnosers is not necessary, and that one can rely on simpler systems, with up to an exponential gain in complexity
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