The Two-Component Virial Theorem and the Physical Properties of Stellar Systems

Motivated by present indirect evidences that galaxies are surrounded by dark matter halos, we investigate whether their physical properties can be described by a formulation of the virial theorem which explicitly takes into account the gravitational potential term representing the interaction of the dark halo with the barionic or luminous component. Our analysis shows that the application of such a ``two-component virial theorem'' not only accounts for the scaling relations displayed, in particular, by elliptical galaxies, but also for the observed properties of all virialized stellar systems, ranging from globular clusters to galaxy clusters.Comment: 13 pages, 2 figures, LaTeX, corrected few typos. This version matches the published versio

Brand gender and consumer-based brand equity on Facebook: The mediating role of consumer-brand engagement and brand love

Brand gender has been suggested as a relevant source of consumer-based brand equity (CBBE). The purpose of this paper is to deepen understanding of the relationship between brand gender and CBBE by analyzing the mediating roleofconsumer–brandengagement (CBE)andbrandlove(BL)onthisrelationship.Thisresearchwas conducted on Facebook, the dominant global social media platform. The hypotheses were tested using structural equation modeling. Results support 6 of the 9 hypotheses, with a significant relationship between analyzed constructs. This study advances prior work by showing that brand gender has an indirect and relevant impact on CBBE through BL and CBE. Therefore, this research confirms the advantages of clear gender positioning and extends prior research by suggesting that brands with a strong gender identity will encourage BL and CB

Cancer Screening in the Coronavirus Pandemic Era: Adjusting to a New Situation.

PURPOSE The coronavirus-induced pandemic has put great pressure on health systems worldwide. Nonemergency health services, such as cancer screening, have been scaled down or withheld as a result of travel restrictions and resources being redirected to manage the pandemic. The present article discusses the challenges to cancer screening implementation in the pandemic environment, suggesting ways to optimize services for breast, cervical, and colorectal cancer screening. METHODS The manuscript was drafted by a team of public health specialists with expertise in implementation and monitoring of cancer screening. A scoping review of literature revealed the lack of comprehensive guidance on continuation of cancer screening in the midst of waxing and waning of infection. The recommendations in the present article were based on the advisories issued by different health agencies and professional bodies and the authors' understanding of the best practices to maintain quality-assured cancer screening. RESULTS A well-coordinated approach is required to ensure that essential health services such as cancer management are maintained and elective services are not threatened, especially because of resource constraints. In the context of cancer screening, a few changes in invitation strategies, screening and management protocols and program governance need to be considered to fit into the new normal situation. Restoring public trust in providing efficient and safe services should be one of the key mandates for screening program reorganization. This may be a good opportunity to introduce innovations (eg, telehealth) and consider de-implementing non-evidence-based practices. It is necessary to consider increased spending on primary health care and incorporating screening services in basic health package. CONCLUSION The article provides guidance on reorganization of screening policies, governance, implementation, and program monitoring

"Fundamental-Plane"-Like Relations From Collisionless Stellar Dynamics: A Comparison of Mergers and Collapses

We present a new set of dissipationless N-body simulations aiming to better understand the pure dynamical aspects of the ``Fundamental Plane'' (FP) of elliptical galaxies. We have extended our previous hierarchical merger scheme by considering the Hernquist profile for the initial galaxy model. Two-component Hernquist galaxy models were also used to study the effect of massive dark halos on the end-products characteristics. We have also performed new collapse simulations including initial spin. We found that the one-component Hernquist mergers give results similar to those found for the one-component King models, namely both were able to build-up small scatter FP-like correlations with slopes consistent with what is found for the near-infrared FP of nearby galaxies. The two-component models also reproduce a FP-like correlation, but with a significantly steeper slope. This is in agreement with what has been found for elliptical galaxies at higher redshift (0.1 $<$ z $<$ 0.6). We discuss some structural properties of the simulated galaxies and their ability to build-up FP-like correlations. We confirm that collapses generally do not follow a FP-like correlation regardless of the initial spin. We suggest that the evolution of gradients in the gravitational field of the merging galaxies may be the main ingredient dictating the final non-homology property of the end products.Comment: 15 pages, 11 figures, uses mn2e.cls. Accepted for publication in MNRA

Implementation of boolean neural networks on parallel computers

This paper analyses the parallel implementation using networks of transputers of a neural structure belonging to a particular class of neural architectures known as GSN neural networks. These architectures, belonging to the general clasa of RAM-based networks and composed 01 digitally specified processing nodes, have been implemented using different processing topologies, and performance in relatíon to both training and testing efficiency in a practical pattern recognition task has been evaluated.Eje: Redes Neuronales. Algoritmos genéticosRed de Universidades con Carreras en Informática (RedUNCI