Robust Covariance Adaptation in Adaptive Importance Sampling

Importance sampling (IS) is a Monte Carlo methodology that allows for approximation of a target distribution using weighted samples generated from another proposal distribution. Adaptive importance sampling (AIS) implements an iterative version of IS which adapts the parameters of the proposal distribution in order to improve estimation of the target. While the adaptation of the location (mean) of the proposals has been largely studied, an important challenge of AIS relates to the difficulty of adapting the scale parameter (covariance matrix). In the case of weight degeneracy, adapting the covariance matrix using the empirical covariance results in a singular matrix, which leads to poor performance in subsequent iterations of the algorithm. In this paper, we propose a novel scheme which exploits recent advances in the IS literature to prevent the so-called weight degeneracy. The method efficiently adapts the covariance matrix of a population of proposal distributions and achieves a significant performance improvement in high-dimensional scenarios. We validate the new method through computer simulations

En torno a motivaciones y efectos del discurso antijudío: el caso de los "Moralia in iob" de Gregorio Magno

La posición de Gregorio Magno frente al judaísmo ha sido analizada en diversas ocasiones, dada la presencia de más de una veintena de epístolas referidas a la problemática compiladas en el Registrum epistularum. Sin embargo, con el fin de obtener una mirada holística sobre su posición, es necesario contemplar toda la producción del obispo de Roma entre 590 y 604 d.C. En este sentido, el análisis de la imagen de los judíos desplegada en los Moralia in Iob ―la obra gregoriana más importante― se torna fundamental. En este artículo, se despliega minuciosamente el conjunto de topoi utilizados por Gregorio al momento de referir al judaísmo: incredulidad; perfidia; apego irracional a la literalidad de la ley; deicidio; castigo divino producto del rechazo a Cristo; conversión en el fin de los tiempos, etc. Se debate, a partir de tal repertorio, si es posible detectar alguna intencionalidad gregoriana tras la iteración de tópicos o si el obispo se limita a utilizar la figura del judío veterotestamentario para explicar el plan divino y, a su vez, estigmatizar algunas conductas seguidas por los cristianos.Fil: Laham Cohen, Rodrigo Jaime. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Do entrepreneurship programmes raise entrepreneurial intention of science and engineering students? The effect of learning, inspiration and resources

Drawing on the theory of planned behaviour, this study tests the effect of entrepreneurship programmes on the entrepreneurial attitudes and intentions of science and engineering students. This is necessary in order to confirm (or disconfirm) conventional wisdom that entrepreneurship education increases the intention to start a business. The results show that the programmes raise some attitudes and the overall entrepreneurial intention and that inspiration (a construct with an emotional element) is the programmes' most influential benefit. The findings contribute to the theories of planned behaviour and education and have wider implications for a theory of entrepreneurial emotions and also for the practice of teaching entrepreneurship

¿Judíos o cristianos? Los adversarios religiosos en la Apología contra los judíos de Leoncio de Neápolis

En algún punto del siglo vii, Leoncio de Neápolis escribió un texto del cual sólo han llegado a nosotros fragmentos aislados, transmitidos con el nombre de Apología o Apología contra los judíos. Es difícil desentrañar el objetivo general de la apología dado que, quienes recuperaron el texto en la propia Antigüedad Tardía, seleccionaron sólo partes de él. Las incertidumbres que genera el material escrito se relacionan, también, con la falta de precisión en torno a la vida y la producción de Leoncio. Intentaremos, en este breve trabajo, analizar la Apología y recuperar su contexto de producción para comprender las principales razones que pudieron haber motivado su escritura. Como advertimos, de Leoncio poseemos poca información. Sabemos que fue obispo de Neápolis, en Chipre, hacia mediados del siglo vii . Escribió, además de la Apología, la Vida de Juan el Limosnero, patriarca de Constantinopla entre los años 606 y 616. Compuso también la Vida de Simeón el loco, eremita de fines del siglo vi, y la Vida de Espiridón (ca. 270–348), obispo de Trimitunte (Chipre), santo y taumaturgo. Es autor de dos homilías (Sobre el anciano Simeón en Lucas 2: 22 y Sobre la fiesta de mesopentecostés). Se supone que es el mismo Leoncio mencionado en el concilio laterano de 649. La fecha de su muerte no ha permanecido en la memoria, así como tampoco el lugar. Se suele estimar, no obstante, que falleció en el exilio, luego de la conquista árabe, hacia el 670 d. C.Fil: Laham Cohen, Rodrigo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Sapere, Analía Verónica. Universidad del Salvador; Argentina. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Iudaei et Iudaei baptizati in the Visigoth law

La decisión de Sisebuto de convertir forzosamente a los judíos, en una fecha cercana al 616 d.C., conformó un nuevo e intrincado mapa identitario en la sociedad visigoda. La definición de la pertenencia religiosa se volvería, así, un aspecto recurrente en la legislación hispana del siglo VII. En este trabajo, nos proponemos revisitar, por una parte, el problema que la polisemia del término Iudaeus genera al momento de realizar un análisis histórico a partir de la normativa visigoda. Por otra parte, analizaremos la mentada legislación, con el fin de delimitar las posibilidades de recuperar el contexto social y religioso en el que fue producida.Sisebute´s decision to force the conversion of Jews in 616 AD created a new and intricate identity map in the Visigothic society. In this context, the demarcation of religious belonging became a recurrent aspect in the Hispanic legislation during the 7th century. The purpose of this work is to clarify, on the one hand, the problem that the polysemy of the term Iudaeus creates in order to carry out an historical analysis through the visigothic law. On the other hand, we will analyze this legislation with the aim of demarcating the possibilities of restoring the social and religious context in which it was produced.Fil: Laham Cohen, Rodrigo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Departamento de Historia; ArgentinaFil: Pecznik, Carolina Andrea. Universidad de Buenos Aires; Argentin

Alliance or acquisition? A mechanisms‐based, policy‐capturing analysis

Research summary: While alliance researchers view prior partner‐specific alliance experience as influencing firms' subsequent alliance or acquisition decisions, empirical evidence on the alliance versus acquisition decision is surprisingly mixed. We offer a reconciliation by proposing and testing an analytical framework that recognizes prior partner‐specific experiences as heterogeneous along three fundamental dimensions: partner‐specific trust, routines, and value certainty. This allows us to use a policy‐capturing methodology to rigorously operationalize and test our mechanism‐level predictions. We find that all three mechanisms can increase the likelihood of a subsequent alliance or acquisition, and in terms of the comparative choice between alliances versus acquisitions, partner‐specific trust pulls towards alliances, and value certainty pulls towards acquisitions. We conclude with a discussion of the theoretical and empirical implications of our approach and method. Managerial summary: This study focuses on an important corporate decision: When a firm has had an alliance with another firm, how would that experience affect the likelihood of a future alliance or acquisition with that same firm? We first suggest that it will depend on three factors: the level of trust that existed in that prior alliance, the extent to which specific work routines were developed, and the degree to which the firm was able to confidently assess the value of the partner firm's resources. We then find that trust is a particularly strong predictor of future alliances, while confidence regarding value more strongly predicts future acquisitions. In this way, we demonstrate more precisely how past corporate choices can affect (consciously or unconsciously) future ones

Meeting the Psychological Needs of Astronauts in the Flourishing Human Spaceflight Frontier: The Case for Astronaut-Trained Psychologists

Space psychology (i.e., astronaut psychological counseling and support) has remained largely unchanged since the onset of long-duration low-Earth-orbit (LEO) human spaceflight missions, with teletherapy utilized as the primary means of psychotherapy delivery. However, with NASA’s plans to establish a permanent human presence on the Moon, the suitability of teletherapy – as well as astronaut-trained psychologists, an alternative space psychology method suggested for human spaceflight beyond LEO – must be ascertained. The aim of this novel space psychology investigation was to identify and compare the effectiveness of three astronaut psychotherapy treatment conditions (i.e., teletherapy with a 2 second Earth to LEO latency, teletherapy with a 10 second Earth to Moon latency, and in-person astronaut trained psychologist delivered therapy with practically no latency) at reducing stress levels among astronauts/astronaut-surrogates in an analogue human spaceflight environment. 24 screened astronaut-surrogates randomly underwent each of the astronaut psychotherapy treatments, and no astronaut-surrogate received repeated treatments. Stress indicators (i.e., heart rate, blood pressure, and self-reported perceived stress questionnaire scores) were measured at multiple intervals throughout the psychotherapy treatment sessions and were analyzed via repeated measures ANOVA. By all metrics, the astronaut-trained psychologist treatment significantly outperformed both teletherapy treatments at reducing stress; and teletherapy with 10 second latency was deemed unsuitable for astronauts. Thus, astronaut-trained psychologists appear to be the most efficacious feasibly integrable space psychology solution for improving wellbeing and reducing stress among individual astronauts and astronaut crews in future long duration human spaceflight operations and missions beyond LEO (e.g., NASA’s Artemis Lunar mission). Additionally, astronaut-trained psychologists appear to be highly effective when operating in LEO as well, and therefore are also ideal for space tourism and commercial astronaut applications

Antijudaísmo teológico en Gregorio Magno

The Christian use of anti-Jewish topics during the first millennium has generated discussions concerning the reasons for that discursive practice. Some researchers have considered a genuine conflict between Jews and Christians as the root of the Adversus Iudaeos literature. In contrast, another position emphasized discursive aspects, highlighting the Christian need for defining its identity in opposition to the Jewish past. From that point of view anti-Judaism thus stands as a textual question largely disconnected from the social context. The work of Gregory the Great, due to its noticeable textual variability, becomes a fundamental tool to understand the dynamics of anti-Judaism. In this article we explore all the Gregorian texts in a qualitative and quantitative analysis, underlining the kind of texts in which the topoi Adversus Iudaeos appear and concluding that, at least for the Pope between 590 and 604, anti-Judaism was a strictly symbolic question.El uso de tópicos antijudíos por parte de los hombres de Iglesia del primer milenio ha suscitado debates en torno a las razones que motivaron tal práctica discursiva. Una línea de investigación enfatizó la existencia de un conflicto real entre judíos y cristianos, hecho que habría derivado en la constitución de la literatura Adversus Iudaeos. En contraste, otra posición hizo hincapié en aspectos discursivos, resaltando la necesidad cristiana de autodefinición en oposición a la matriz judía y confinando el antijudaísmo a cuestiones estrictamente textuales e identitarias distantes del contexto social inmediato. La figura de Gregorio Magno, gracias a la gran variabilidad textual que presenta su obra, otorga una herramienta fundamental a la hora de comprender las dinámicas del antijudaísmo cristiano. En este artículo se exploran todos los escritos gregorianos, mediante un estudio cualitativo y cuantitativo, poniéndose de releve en qué tipo de textos aparecen los topoi Adversus Iudaeos y concluyendo que, al menos para el Papa entre el 590 y el 604, el antijudaísmo fue una cuestión estrictamente simbólica

THE EFFECT OF ꞵ -CARYOPHYLLENE ON ISOPROTERENOL-INDUCED MYOCARDIAL INFARCTION

Cannabinoid type 2 receptors (CB2), a key member of the endocannabinoid system have recently emerged as a crucial therapeutic target for cardiovascular diseases (CVDs). Downregulation of CB2 receptors has been witnessed in various cancers, neurological and cardiovascular disorders. Thus, the activation of CB2 receptors may protect against ISO-induced myocardial infarction (MI) in rats. The present study investigates the cardioprotective effect of a selective cannabinoid type 2 receptor agonist β-caryophyllene (BCP), a dietary phytocannabinoid, and a natural bicyclic sesquiterpene against isoproterenol (ISO)-induced MI in rats. Male albino Wistar rats were pre-and co-treated with β-caryophyllene (50 mg/kg, orally) twice daily for 10 days along with the subcutaneous injection of ISO (85 mg/kg) at an interval of 24 h for two days (9th and 10th day). AM630 (1 mg/kg), a CB2 receptor antagonist was injected intraperitoneally as a pharmacological challenge prior to BCP treatment to demonstrate CB2 receptor-mediated cardioprotective mechanisms of BCP. ISO-induced MI showed a significant decline in cardiac function, elevated levels of serum cardiac marker enzymes, and enhanced oxidative stress markers with increased lipid peroxidation. Isoproterenol also induced pro-inflammatory cytokines release following activation of the nuclear factor kappa-B. Furthermore, a significant rise was also observed in the levels of inflammatory mediators, namely cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in ISO-challenged rats. Additionally, Isoproterenol also increased the expression of pro-apoptotic (Bax, and active caspase-3) proteins along with the decreased expression of the anti- apoptotic protein, Bcl2, and Bcl-xL in the myocardium. β-caryophyllene treatment resulted in significant protective effects on all biochemical and molecular parameters analyzed. Histopathological and ultrastructural evidence was found in line with these findings. Treatment with AM630, a potent CB2 receptor antagonist abrogates protective effects\ of BCP on all the biochemical and molecular parameters analyzed in ISO induced MI in rats. Thus, this study revealed that BCP protects the myocardium against ISO-induced MI by attenuating oxidative stress, apoptosis, and inflammation and the underlying mechanism of this protection is the activation of CB2 receptors. CB2 receptor-selective compounds may provide a new potential class of cardioprotective drugs. The pharmacophore of these compounds could be used for synthesizing leads in drug discovery and development