Exploring Disk Galaxy Dynamics Using IFU Data

In order to test the basic equations believed to dictate the dynamics of disk galaxies, we present and analyze deep two-dimensional spectral data obtained using the PPAK integral field unit for the early-type spiral systems NGC 2273, NGC 2985, NGC 3898 and NGC 5533. We describe the care needed to obtain and process such data to a point where reliable kinematic measurements can be obtained from these observations, and a new more optimal method for deriving the rotational motion and velocity dispersions in such disk systems. The data from NGC 2273 and NGC 2985 show systematic variations in velocity dispersion with azimuth, as one would expect if the shapes of their velocity ellipsoids are significantly anisotropic, while the hotter disks in NGC 3898 and NGC 5533 appear to have fairly isotropic velocity dispersions. Correcting the rotational motion for asymmetric drift using the derived velocity dispersions reproduces the rotation curves inferred from emission lines reasonably well, implying that this correction is quite robust, and that the use of the asymmetric drift equation is valid. NGC 2985 is sufficiently close to face on for the data, combined with the asymmetric drift equation, to determine all three components of the velocity ellipsoid. The principal axes of this velocity ellipsoid are found to be in the ratio sigma_z:sigma_phi:sigma_R ~ 0.7:0.7:1, which shows unequivocally that this disk distribution function respects a third integral of motion. The ratio is also consistent with the predictions of epicyclic theory, giving some confidence in the application of this approximation to even fairly early-type disk galaxies.Comment: 15 pages, 7 figures, accepted for publication in MNRA

Differences in carbon and nitrogen abundances between field and cluster early-type galaxies

Central line-strength indices were measured in the blue spectral region for a sample of 98 early-type galaxies in different environments. For most indices (Mgb and in particular) ellipticals in rich clusters and in low-density regions follow the same index-sigma relations. However, striking spectral differences between field ellipticals and their counterparts in the central region of the Coma cluster are found for the first time, with galaxies in the denser environment showing significantly lower C4668 and CN2 absorption strengths. The most convincing interpretation of these results is a difference in abundance ratios, arising from a distinct star formation and chemical enrichment histories of galaxies in different environments. An scenario in which elliptical galaxies in clusters are fully assembled at earlier stages than their low-density counterparts is discussed.Comment: 12 pages, including 3 figures, accepted for publication in ApJ

Constraints on decaying Dark Matter from XMM-Newton observations of M31

We derive constraints on parameters of the radiatively decaying Dark Matter (DM) particles, using XMM-Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5'-13') parts of M31 we improve the existing constraints. For the case of sterile neutrino DM, combining our constraints with the latest computation of abundances of sterile neutrino in the Dodelson-Widrow (DW) scenario, we obtain the lower mass limit m_s < 4 keV, which is stronger than the previous one m_s < 6 kev, obtained recently by Asaka et al. (2007) [hep-ph/0612182]. Comparing this limit with the most recent results on Lyman-alpha forest analysis of Viel et al. (2007) [arXiv:0709.0131] (m_s > 5.6 kev), we argue that the scenario in which all the DM is produced via DW mechanism is ruled out. We discuss however other production mechanisms and note that the sterile neutrino remains a viable candidate of Dark Matter, either warm or cold.Comment: 13 pages, 12 figure

Proceedings of the 2003 Winter Simulation Conference

In this paper we have applied an interval representation of time to represent and reason about activities, events, actions and situations relevant to the construction domain. The first part of the paper formally defines the situational simulation environment and develops a set of temporal axioms which can be used to 1) Express precedence constraints between time intervals and 2) Capture the causal relationships between actions and events. The second part of the paper looks at an agent reasoning mechanism used to perceive and predict actions and foresee future consequences of present actions within the simulation environment. Agent reasoning is based on awareness derived from a knowledge base of facts which captures the causal nature of events in the construction management domain

Research results applied to the field of health: how experience impacts the classroom and society

The Health Sciences Faculty of the Universidad Tecnológica de Pereira has been advancing in the generation of new knowledge and has explored various fields of knowledge. This book presents four pieces of research that have a lot to do with new trends, both in the training of human talent in health, and in the way in which knowledge and technology are applied to solutions to context problems. In this case, it is important to mention the role that high-fidelity clinical simulation has been gaining in the training processes of our students, more specifically the use of theater and the “standardized patients” strategy, in the promotion of professional criteria. The positive impact of a focused training is evident, both in the conceptual development of the individual, and in the appropriation of his role as an agent of social change. The theater promotes an intentional interaction with which knowledge, skills and attitudes can be explored in a medical training process. Likewise, theater has been used as a useful tool in the introduction of therapeutic elements in hospital spaces, such as pediatric, oncology or mental health wards, promoting various ways of interacting with medical staff, or exploring personal aspects. that can improve the clinical evolution of patients. Clinical simulation also contemplates a series of technological elements that, when used for educational purposes, can also promote performance analysis of cognitive, technical, and dexterity skills. This is the case of the clinical simulation put to the service of a CPR skills analysis project, in which, through sensors and performance variables such as force, pressure or response time, they can account for advances in CPR training processes, both for university communities and for health professionals.PregradoCONTENT Introduction ....................................................................................................................5 CHAPTER ONE Project Jai Kazhirua: Actors for clinical simulation .......................................................9 Julio César Sánchez Naranjo, Heidy Yicel Mesa Arenas and Andrés Felipe Ramírez Herrera CHAPTER TWO Implementation of a flipped classroom methodology in the medical physiology course in the Faculty of Health Sciences ...................................................31 Julio César Sánchez Naranjo, Diego Fernando López Zapata, Óscar Alonso Pinzón Duque, Andrés Mauricio García Cuevas, Martha Doris Morales Medina and Samuel Eduardo Trujillo Henao CHAPTER THREE SANAR RIENDO (HEALING LAUGHTER): humor therapy for pediatric hospitalized patients.................................................................................53 Julio César Sánchez Naranjo, Heidy Yicel Mesa Arenas and Andrés Felipe Ramírez Herrera CHAPTER FOUR CPR performance characteristics of emergency teams in the city of Pereira, Colombia .....................................................................................................77 Giovanni García Castro, Yamileth Estrada Berrio, Johana Andrea Méndez Timaná, and Sandra Milena Bedoya Gaviri

Comparison of silver-plated nylon (Ag/PA66) e-textile and Ag/AgCl electrodes for bioelectrical impedance analysis (BIA)

Recently, researchers have adapted Bioelectrical Impedance Analysis (BIA) as a new approach to objectively monitor wounds. They have indicated various BIA parameters associated to specific wound types can be linked to wound healing through trend analysis relative to time. However, these studies are conducted using wet electrodes which have been identified as possessing several shortcomings, such as unstable measurements. Thus, the adaption of e-textile electrodes has become an area of interest in measuring biosignals. E-textile electrodes are known to possess a significantly large polarization impedance (Zp) that potentially influences these biosignal measurements. In this study we aim to identify the suitability of e-textile electrodes to monitor wounds using BIA methodologies. By adapting suggested methodologies conducted in-vivo from previous studies, we used an ex-vivo model to observe the behaviour of e-textile electrodes relative to time. This was compared to common clinical wet electrodes, specifically Ag/AgCl. The objective of this study was to identify the BIA parameters that can be used to monitor wounds with e-textile electrodes. By analysing the BIA parameters relative to time, we observed the influence of Zp on these parameters.Peer ReviewedPostprint (author's final draft

Neutron capture measurement at the n TOF facility of the 204Tl and 205Tl s-process branching points

Neutron capture cross sections are one of the fundamental nuclear data in the study of the s (slow) process of nucleosynthesis. More interestingly, the competition between the capture and the decay rates in some unstable nuclei determines the local isotopic abundance pattern. Since decay rates are often sensible to temperature and electron density, the study of the nuclear properties of these nuclei can provide valuable constraints to the physical magnitudes of the nucleosynthesis stellar environment. Here we report on the capture cross section measurement of two thallium isotopes, $^{204}$Tl and $^{205}$Tl performed by the time-of-flight technique at the n TOF facility at CERN. At some particular stellar s-process environments, the decay of both nuclei is strongly enhanced, and determines decisively the abundance of two s-only isotopes of lead, $^{204}$Pb and $^{205}$Pb. The latter, as a long-lived radioactive nucleus, has potential use as a chronometer of the last s-process events that contributed to final solar isotopic abundances