Gradient-Based Spectral Embeddings of Random Dot Product Graphs

The Random Dot Product Graph (RDPG) is a generative model for relational data, where nodes are represented via latent vectors in low-dimensional Euclidean space. RDPGs crucially postulate that edge formation probabilities are given by the dot product of the corresponding latent positions. Accordingly, the embedding task of estimating these vectors from an observed graph is typically posed as a low-rank matrix factorization problem. The workhorse Adjacency Spectral Embedding (ASE) enjoys solid statistical properties, but it is formally solving a surrogate problem and can be computationally intensive. In this paper, we bring to bear recent advances in non-convex optimization and demonstrate their impact to RDPG inference. We advocate first-order gradient descent methods to better solve the embedding problem, and to organically accommodate broader network embedding applications of practical relevance. Notably, we argue that RDPG embeddings of directed graphs loose interpretability unless the factor matrices are constrained to have orthogonal columns. We thus develop a novel feasible optimization method in the resulting manifold. The effectiveness of the graph representation learning framework is demonstrated on reproducible experiments with both synthetic and real network data. Our open-source algorithm implementations are scalable, and unlike the ASE they are robust to missing edge data and can track slowly-varying latent positions from streaming graphs

Online change point detection for weighted and directed random dot product graphs

Given a sequence of random (directed and weighted) graphs, we address the problem of online monitoring and detection of changes in the underlying data distribution. Our idea is to endow sequential change-point detection (CPD) techniques with a graph representation learning substrate based on the versatile Random Dot Product Graph (RDPG) model. We consider efficient, online updates of a judicious monitoring function, which quantifies the discrepancy between the streaming graph observations and the nominal RDPG. This reference distribution is inferred via spectral embeddings of the first few graphs in the sequence. We characterize the distribution of this running statistic to select thresholds that guarantee error-rate control, and under simplifying approximations we offer insights on the algorithm’s detection resolution and delay. The end result is a lightweight online CPD algorithm, that is also explainable by virtue of the well-appreciated interpretability of RDPG embeddings. This is in stark contrast with most existing graph CPD approaches, which either rely on extensive computation, or they store and process the entire observed time series. An apparent limitation of the RDPG model is its suitability for undirected and unweighted graphs only, a gap we aim to close here to broaden the scope of the CPD framework. Unlike previous proposals, our non-parametric RDPG model for weighted graphs does not require a priori specification of the weights’ distribution to perform inference and estimation. This network modeling contribution is of independent interest beyond CPD. We offer an open-source implementation of the novel online CPD algorithm for weighted and direct graphs, whose effectiveness and efficiency are demonstrated via (reproducible) synthetic and real network data experimentsWork in this paper is supported in part by ANII (grant FMV 3 2018 1 148149) and the NSF (awards CCF-1750428, CCF-1934962 and ECCS-1809356). Part of the results in this paper were submitted to the 2021 EUSIPCO and Asilomar Conference

Mirtazapine for the treatment of hot flushes in breast cancer survivors: a prospective pilot trial.

The purposes of the study are to evaluate the efficacy and safety of mirtazapine 30 mg/daily for 12 weeks to reduce hot flushes (HF) in women with previous breast cancer and to assess the influence of the same treatment on sleep quality and other menopausal symptoms. A prospective pilot trial was conducted in 40 breast cancer patients with at least seven HF per day. A HF diary was completed daily; sleep quality and other menopausal symptoms were assessed with the Pittsburgh Sleep Quality Index (PSQI), the Menopause Rating Scale (MRS) and the SF-36 Health Survey. Treatment was never started by 13 out of 40 patients (32.5%) and was interrupted by 7 out of 27 patients (25%) due to of the occurrence of side effects (mostly somnolence). In the remaining 20 patients who completed the three months treatment period, there was a 55.6% (p < 0.05) reduction in HF frequency and 61.9% (p < 0.05) reduction in HF score as compared to baseline. A significant reduction in the MRS score (32.8%; p < 0.05) was observed. Mirtazapine appears to be effective in reducing HF in breast cancer survivors. The more frequent side effect was somnolence. A sizeable compiliance problem has been observed due to the reluctance to take antidepressant drugs and to side effects

Learning science through art: the atelier as an opportunity for teaching innovation

The objective of our work is to analyze different scientific objects and study possible didactic strategies conveyed by the atelier device. We will use as a methodology the survey of educational experiences, and scientific concepts suitable for the stages of childhood, which we will cross with some key definitions used by different artists and movements. We will focus on those strategies that artistic practice helps to link with pedagogical practices, in order to propose some methodologies of didactic innovation. We propose that education can take the active methodology and experimentation of art, of questioning and reflection that are at the center of contemporary artistic practices, with pedagogical purposes that aim at a better understanding of some relevant scientific concepts and phenomena.El objetivo de nuestro trabajo es analizar diferentes objetos científicos y estudiar posibles estrategias didácticas vehiculizadas por el dispositivo de atelier. Utilizaremos como metodología el relevamiento de experiencias educativas, y de conceptos científicos adecuados para las etapas de infancia, que cruzaremos con algunas definiciones clave utilizadas por distintos artistas y movimientos. Nos centraremos en aquellas estrategias que la práctica artística contribuye a vincular con las prácticas pedagógicas, a fin de plantear algunas metodologías de innovación didáctica. Proponemos que la educación pueda tomar la metodología activa y de experimentación del arte, de cuestionamiento y reflexión que están en el centro de las prácticas artísticas contemporáneas, con fines pedagógicos que apunten a la mejor comprensión de algunos conceptos y fenómenos científicos relevantes

Comportamiento del Consumidor: La personalidad y comportamiento del consumidor como individuo

El presente trabajo de seminario de graduación, tiene por tema comportamiento del consumidor y como subtema la personalidad y comportamiento del consumidor como individuo, tomando en cuenta los factores internos y externos que influyen en la decisión de compra del consumidor. Dicha investigación lleva como finalidad, analizar al consumidor como individuo, desde sus características y todo su entorno social y cultural. El comportamiento del consumidor es una pieza fundamental para la sociedad, es una manera constante de crear ciertas atracciones y necesidades para los productos, siendo así para mantener la fidelidad de los consumidores y así obtener la participación de ellos. El estudio del consumidor en el comportamiento y personalidad orienta al mercadólogo a entender la percepción de lo que el cliente desea, lo que prefiere, lo que lo motiva y la necesidad que tiene por satisfacer. Entre los principales factores que influyen en el comportamiento del consumidor en la decisión de compra tenemos los aspectos cultural, social, personal, psicológicas y comprador. Al mismo tiempo se puede observar el proceso de compra por el que pasa un individuo, estas son: reconocimiento de la necesidad, búsqueda de información, evaluación de alternativas, decisión de compra y comportamiento posterior a la compra. Se pretende comprender la personalidad y comportamiento del consumidor como individuo mediante la compilación de información referente a los aspectos teóricos fundamentales de la personalidad y comportamiento del consumidor como individuo. La metodología utilizada fue la recolección de datos teóricos a través del fichero bibliográfico y de contenido, pretendiendo cumplir con los objetivos propuestos en dicha investigación

La gestión de la práctica formativa como proceso de reconstrucción del saber pedagógico

En el presente artículo se describe una experiencia de gestión de aula realizada con un grupo de 27 estudiantes de cuarto año de la Licenciatura de Educación Inicial de la Universidad Católica del Uruguay, en el marco del curso “Supervisión de práctica profesional II”. El objetivo general de la experiencia reside en desarrollar habilidades que promuevan la profesionalización del rol docente, habilitando la búsqueda de soluciones pertinentes a dificultades encontradas por las estudiantes en sus prácticas formativas. La propuesta del aula universitaria se encuadra en un marco curricular orientado por competencias, lo que implica atender a las necesidades y dificultades detectadas por las estudiantes. Ellas señalaron como problema principal que la puesta en marcha de los currículos oficiales vigentes genera inconvenientes al momento de gestionar situaciones educativas en el aula. Desde esta realidad, se elaboró un documento que opera como organizador de la labor educativa. El trabajo ofrece al campo de la gestión educativa una experiencia innovadora que permite reflexionar y actuar sobre la propuesta que ofrece el docente y sus resultados. Se promueven acciones de innovación para dar respuesta a una problemática del contexto educativ

Come gestire un tirocinio clinico in modalità e-learning: l’esperienza del Corso di Laurea in Infermieristica di Torino

Introduction: The COVID-19 pandemic has required to drammatically reorganize students’ education at all levels including the university level, with classroom education being replaced by distance learning. Bachelor of Nursing Science degrees had to restructure clinical learning experiences in addition to the theoretical education while guaranteeing educational objectives to be achieved. Methods: This paper presents two experiences of the Bachelor of Nursing Science degree of Turin to manage remote clinical learning experiences due to students’ impossibility to attend safely hospital wards. Results: Reported experiences show that remote clinical learning guarantees the development of decision making-related complex cognitive skills and the methodology of the ‘clinical case’ fits well e-learning education. Discussion: In the future, a blend of in-person and remote clinical learning experience may be introduced. Complex decision-making skills can be stimulated and promoted even remotely, however, the clinical learning experience at the patient’s bedside needs to be preserved to promote professional growth and team-working skills.Introduzione: La pandemia da COVID-19 ha richiesto una profonda riorganizzazione della didattica a tutti i livelli, incluso quello universitario, con la formazione in aula sostituita da quella a distanza. I Corsi di Laurea in Infermieristica si sono trovati a dover riprogettare oltre alla formazione teorica anche i tirocini clinici, cercando di garantire il raggiungimento degli obiettivi formativi. Metodi: Questo lavoro presenta due esperienze del Corso di Laurea in Infermieristica di Torino per la gestione del tirocinio clinico a distanza data l’impossibilità per gli studenti di frequentare i reparti di degenza in sicurezza. Risultati: Le esperienze presentate mettono in luce come il tirocinio clinico a distanza garantisca lo sviluppo di competenze cognitive complesse relative ai processi decisionali e come la metodologia del ‘caso clinico’ si adatti bene a una modalità didattica e-learning. Discussione: In futuro si potrebbe ipotizzare l’introduzione di tirocini in modalità blended. Le competenze decisionali complesse possono essere stimolate e promosse anche a distanza, ma l’esperienza formativa clinica al letto del malato deve essere preservata perché rappresenta un aspetto formativo imprescindibile per la crescita professionale e lo sviluppo dell’abilità di lavorare in gruppi multidisciplinari

Experiencia del uso de la cánula nasal de alto flujo en cuidados intensivos neonatales de un hospital a 2,600 metros sobre el nivel del mar

Introducción: Las grandes altitudes disminuyen la presión de oxígeno ambiental, lo que amerita fracciones inspiratorias de oxígeno (FiO2) más elevadas. Las cánulas nasales de alto flujo (CNAF) representan una estrategia que mejora el aporte de oxígeno sin alterar la comodidad del paciente. Objetivo: Describir el uso de CNAF en pacientes que ingresan a la unidad de cuidados intensivos neonatales (UCIN) de un centro a una altitud de 2,600 metros sobre el nivel del mar. Material y métodos: Se realizó un estudio descriptivo en pacientes que ingresaron a una UCIN en la ciudad de Bogotá, Colombia. Se recolectaron características demográficas, diagnósticos clínicos, signos vitales, flujos, FiO2 y el grado de dificultad respiratoria mediante la escala de Silverman-Andersen. Se determinaron los tiempos de uso, estancia hospitalaria y la frecuencia de falla o eventos adversos. Resultados: Se estudiaron 139 pacientes. La mediana de puntaje de dificultad respiratoria fue bajo (2) con sólo un caso de dificultad respiratoria severa. Se usaron en promedio altas fracciones de FiO2 (50%). En 24 casos falló la terapia (17.2%) y no se reportaron eventos adversos. Conclusiones: El uso de la CNAF en grandes altitudes permite utilizar más FiO2 en pacientes con puntajes bajos de dificultad respiratoria y disminuye la necesidad de recurrir a métodos más invasivos

Concordance between body composition measured with an inbody 120 and a skulpt chisel in adolescent fighting athletes

Introducción: La determinación de la composición corporal forma parte de la valoración morfofuncional del atleta; existiendo diferentes instrumentos para evaluarla. Objetivo: Comparar las mediciones de la composición corporal entre un InBody 120 y un Skulpt Chisel en una muestra de atletas de combate adolescentes. Metodología: Estudio cuantitativo con enfoque analítico, en el que se incluyó 24 varones (14,2±1,9años, 1,6±0,1m, 62,3±16,1kg, IMC 24,2±4,7kg/m2). Los sujetos fueron medidos con ambos instrumentos obteniendo los valores del porcentaje de grasa corporal (%GC), masa grasa (MG), porcentaje de masa muscular (%MM), masa muscular (MM) y calidad muscular (CM); siguiendo las instrucciones de los fabricantes. Se utilizó la prueba de t de student para muestras relacionadas, el coeficiente de correlación de Pearson, el coeficiente de correlación concordancia de Lin y los gráficos de Bland-Altman. Se consideró significativo una p+/-5% y >+/-3kg, de manera respectiva). Conclusiones: Se concluye que las mediciones realizadas por ambos instrumentos presentaron correlaciones elevadas, pero no son concordantes ni intercambiables.Introduction: The determination of body composition is part of the athlete's morphofunctional assessment; there are different instruments to evaluate it. Objective: To compare the measurements of body composition between an InBody 120 and a Skulpt Chisel in a group of adolescents’ combat athletes. Methodology: Quantitative study with an analytical approach, in which 24 males (14,2±1.9years, 1,6±0,1m, 62,3±16,1kg, BMI 24,2±4,7kg/m2) were included. The subjects were measured with both instruments obtaining the values of the percentage of body fat (%BF), fat mass (FM), percentage of muscle mass (%MM), muscle mass (MM) and muscle quality (MQ); following the manufacturer’s instructions. Student’s t-test for paired samples, Pearson correlation coefficient, Lin’s concordance correlation coefficient and Bland-Altman plots were used. Statistical significance was defined as p<0,05. Results: We did not observe a significant difference between %BF mean values (p=0,161) and FM mean values (p=0,141) in the population at large, but we did see a difference in the FM of Tae Kwon Do practitioners (p=0,042). %BF and FM showed a significant positive correlation between the two teams (r=0,898 y 0,959, respectively; p<0,01), similar to %MM and MQ (r=0,771, p<0,01) but not in the case of MM and QM (r=-0,116, p=0,58). We found poor concordance in the case of %BF (CCC=0,88, IC95%=0,75-0,94) and moderate concordance for FM (CCC=0,95, IC95%=0,89-0,97); furthermore, the Bland-Altman plots showed clinically relevant individual variations for both variables (≥+/-5% and ≥+/-3kg, respectively). Conclusions: We conclude that measurements obtained with the two instruments were highly correlated but they are neither concordant nor interchangeableIncluye referencias bibliográfica