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Taxanes for advanced non-small cell lung cancer (Protocol)
(Cochrane, 2018) Madrid, Eva; Barros Monge, Manuel J; Urrútia, Gerard; Roqué I Figuls, Marta; Pérez Bracchiglione, Javier; Vargas Peirano, Manuel; Loézar Hernández, Cristóbal Nicolás; Bonfill Cosp, Xavier
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of taxanes as part of a combined or single‐agent therapy versus other agents or best supportive care as first‐ or second‐line treatment for advanced non‐small cell lung cancer (NSCLC). A secondary objective is to assess different modes or schemes of administration of taxanes in patients with this disease.
Chaos versus noise as drivers of multistability in neural networks
(Chaos, 2018-10-18) Orio, Patricio; Gatica, Marilyn; Herzog, Rubén; Maidana, Jean Paul; Castro, Samy; Xu, Kesheng
The multistable behavior of neural networks is actively being studied as a landmark of ongoing cerebral activity, reported in both functional Magnetic Resonance Imaging (fMRI) and electro- or magnetoencephalography recordings. This consists of a continuous jumping between different partially synchronized states in the absence of external stimuli. It is thought to be an important mechanism for dealing with sensory novelty and to allow for efficient coding of information in an ever-changing surrounding environment. Many advances have been made to understand how network topology, connection delays, and noise can contribute to building this dynamic. Little or no attention, however, has been paid to the difference between local chaotic and stochastic influences on the switching between different network states. Using a conductance-based neural model that can have chaotic dynamics, we showed that a network can show multistable dynamics in a certain range of global connectivity strength and under deterministic conditions. In the present work, we characterize the multistable dynamics when the networks are, in addition to chaotic, subject to ion channel stochasticity in the form of multiplicative (channel) or additive (current) noise. We calculate the Functional Connectivity Dynamics matrix by comparing the Functional Connectivity (FC) matrices that describe the pair-wise phase synchronization in a moving window fashion and performing clustering of FCs. Moderate noise can enhance the multistable behavior that is evoked by chaos, resulting in more heterogeneous synchronization patterns, while more intense noise abolishes multistability. In networks composed of nonchaotic nodes, some noise can induce multistability in an otherwise synchronized, nonchaotic network. Finally, we found the same results regardless of the multiplicative or additive nature of noise.
Characterization of Retinal Functionality at Different Eccentricities in a Diurnal Rodent
(Frontiers in Cellular Neuroscience, 2018-12-03) Escobar, María José; Reyes, César; Herzog, Rubén; Araya, Joaquín; Otero, Mónica; Ibaceta, Cristóbal; Palacios, Adrián G.
Although the properties of the neurons of the visual system that process central and peripheral regions of the visual field have been widely researched in the visual cortex and the LGN, they have scarcely been documented for the retina. The retina is the first step in integrating optical signals, and despite considerable efforts to functionally characterize the different types of retinal ganglion cells (RGCs), a clear account of the particular functionality of cells with central vs. peripheral fields is still wanting. Here, we use electrophysiological recordings, gathered from retinas of the diurnal rodent Octodon degus, to show that RGCs with peripheral receptive fields (RF) are larger, faster, and have shorter transient responses. This translates into higher sensitivity at high temporal frequencies and a full frequency bandwidth when compared to RGCs with more central RF. We also observed that imbalances between ON and OFF cell populations are preserved with eccentricity. Finally, the high diversity of functional types of RGCs highlights the complexity of the computational strategies implemented in the early stages of visual processing, which could inspire the development of bio-inspired artificial systems.
Pre‐ and postnatal alcohol exposure delays, in female but not in male rats, the extinction of an auditory fear conditioned memory and increases alcohol consumption
(Wiley, 2019) Plaza, Wladimir; Gaschino, Felice; Gutiérrez, Camilo; Santibañez, Nicolás; Estay‐Olmos, Camila; Sotomayor‐Zárate, Ramón; De la Fuente‐Ortega, Erwin; Pautass, Ricardo M.; Haeger, Paola A.
Repeated exposure to alcohol increases retrieval of fear‐conditioned memories, which facilitates, among other factors, the emergence of post‐traumatic stress disorder (PTSD). Individuals with PTSD are more likely to develop alcohol and substance abuse related disorders. We assessed if prenatal and early postnatal alcohol exposure (PAE) increased the susceptibility to retain aversive memories and if this was associated with subsequent heightened alcohol consumption. Pregnant Sprague‐Dawley rats were exposed for 22 hr/day, throughout pregnancy and until postnatal Day 7 to a single bottle of sucralose ‐ sweetened 10% alcohol solution (PAE Group), or to a single bottle of tap water and sucralose (Control Group). Auditory fear conditioning (AFC) was performed in the adolescent offspring at postnatal Day 40. Freezing was measured during acquisition, retention and extinction phases, followed by 3 weeks of free choice alcohol intake. Female, but not male, PAE rats exhibited impaired extinction of the aversive memory, a finding associated with higher levels of 3‐4 Dihidroxyphenylacetic acid (DOPAC) in the nucleus accumbens and heightened alcohol intake, respect to controls. These findings suggest that PAE makes females more vulnerable to long‐term retention of aversive memories, which coexist with heightened alcohol intake. These findings are reminiscent of those of PTSD
Development of Fixed Dose Combination Products Workshop Report: Considerations of Gastrointestinal Physiology and Overall Development Strategy
(Springer, 2019) Hens, Bart; Corsetti, Maura; Bermejo, Marival; Löbenberg, Raimar; González, Pablo M.; Mitra, V; Desai, Divyakant; Murthy Chilukuri, Dakshina; Aceituno, Alexis
The gastrointestinal (GI) tract is one of the most popular and used routes of drug product administration due to the convenience for better patient compliance and reduced costs to the patient compared to other routes. However, its complex nature poses a great challenge for formulation scientists when developing more complex dosage forms such as those combining two or more drugs. Fixed dose combination (FDC) products are two or more single active ingredients combined in a single dosage form. This formulation strategy represents a novel formulation which is as safe and effective compared to every mono-product separately. A complex drug product, to be dosed through a complex route, requires judicious considerations for formulation development. Additionally, it represents a challenge from a regulatory perspective at the time of demonstrating bioequivalence (BE) for generic versions of such drug products. This report gives the reader a summary of a 2-day short course that took place on the third and fourth of November at the Annual Association of Pharmaceutical Scientists (AAPS) meeting in 2018 at Washington, D.C. This manuscript will offer a comprehensive view of the most influential aspects of the GI physiology on the absorption of drugs and current techniques to help understand the fate of orally ingested drug products in the complex environment represented by the GI tract. Through case studies on FDC product development and regulatory issues, this manuscript will provide a great opportunity for readers to explore avenues for successfully developing FDC products and their generic versions.
Inclusión de salud basada en evidencia en carreras de la salud en Chile y el modelo integrado Metodología de la Investigación Científica-Medicina Basada en Evidencia en la Universidad de Valparaíso
(Elsevier, 2019) Papuzinski, Cristian; Loézar, Cristóbal; Carvajal, Natalia; Vargas, Manuel; Borgeat, Marjorie; Madrid, Eva; Pérez-Bracchiglione, Javier; Arancibia, Marcelo
Introducción: La salud basada en evidencia (SBE) integra el uso de la mejor evidencia, la experiencia clínica y los valores y preferencias del paciente para la toma de decisiones. Su incorporación en las carreras sanitarias de Chile es desconocida. Métodos: Se realizó un estudio de corte transversal para evaluar la incorporación de SBE en los programas de las carreras sanitarias en Chile hasta 2019. Se describe la integración del modelo Metodología de la Investigación Científica (MIC)-Medicina Basada en la Evidencia (MBE) en la Escuela de Medicina de la Universidad de Valparaíso. Resultados: Un total de 49 universidades imparten carreras sanitarias. Un 8,13% incorpora SBE como asignatura explícitamente. Todas incorporan asignaturas que potencialmente incluyen contenidos de SBE. Las carreras de Medicina y Enfermería son las que más incorporan SBE, pero solo una carrera de Medicina incluye SBE como asignatura por más de un semestre. El modelo integrado MIC/MBE (4 semestres), orientado en competencias y centrado en el alumno, involucra el diseno ̃ y ejecución de un protocolo de investigación, así como el análisis crítico de la mejor evidencia, integrado con los valores de los pacientes. Conclusión: La incorporación de SBE como asignatura es muy infrecuente en carreras sanitarias chilenas. Se enfatiza su inclusión transdisciplinaria como asignatura individual desde un modelo que integre la ensenanza ̃ de MIC, sobre todo en universidades estatales.
A Comparison of the Maximum Entropy Principle Across Biological Spatial Scales
(Entropy, 2019-10-15) Cofré, Rodrigo; Herzog, Rubén; Corcoran, Derek; Rosas, Fernando E.
Despite their differences, biological systems at different spatial scales tend to exhibit common organizational patterns. Unfortunately, these commonalities are often hard to grasp due to the highly specialized nature of modern science and the parcelled terminology employed by various scientific sub-disciplines. To explore these common organizational features, this paper provides a comparative study of diverse applications of the maximum entropy principle, which has found many uses at different biological spatial scales ranging from amino acids up to societies. By presenting these studies under a common approach and language, this paper aims to establish a unified view over these seemingly highly heterogeneous scenarios.
International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth
(Wiley, 2020) Flores, Marie Therese
Avulsion of permanent teeth is one of the most serious dental injuries. Prompt and correct emergency management is essential for attaining the best outcome after this injury. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. It represents the current best evidence and practice based on that literature search and expert opinions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The purpose of these Guidelines is to provide clinicians with the most widely accepted and scientifically plausible approaches for the immediate or urgent care of avulsed permanent teeth. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.
Exocomets: A spectroscopic survey
(European Southern Observatory, 2020) Bayo, Amelia; Iglesias, Daniela Paz
Context. While exoplanets are now routinely detected, the detection of small bodies in extrasolar systems remains challenging. Since the discovery of sporadic events interpreted as exocomets (Falling Evaporating Bodies) around Pic in the early 80s, only 20 stars have been reported to host exocomet-like events. Aims. We aim to expand the sample of known exocomet-host stars, as well as to monitor the hot-gas environment around stars with previously known exocometary activity. Methods. We have obtained high-resolution optical spectra of a heterogeneous sample of 117 main-sequence stars in the spectral type range from B8 to G8. The data have been collected in 14 observing campaigns expanding over 2 years from both hemispheres. We have analysed the Ca ii K&H and Na i D lines in order to search for non-photospheric absorptions originated in the circumstellar environment, and for variable events that could be caused by outgassing of exocomet-like bodies. Results. We have detected non-photospheric absorptions towards 50% of the sample, attributing a circumstellar origin to half of the detections (i.e. 26% of the sample). Hot circumstellar gas is detected in the metallic lines inspected via narrow stable absorptions, and/or variable blue-/red-shifted absorption events. Such variable events were found in 18 stars in the Ca ii and/or Na i lines; 6 of them are reported in the context of this work for the first time. In some cases the variations we report in the Ca ii K line are similar to those observed in Pic. While we do not find a significant trend with the age or location of the stars, we do find that the probability of finding CS gas in stars with larger v sin i is higher. We also find a weak trend with the presence of near-infrared excess, and with anomalous ( Boo-like) abundances, but this would require confirmation by expanding the sample.
KPSI como herramienta de autoevaluación metacognitiva en el desarrollo de la competencia intercultural en salud en medicina
(Universidad de Tarapacá. Facultad de Ciencias de la Salud, 2020) Guerra-Zúñiga, María; Segovia-Chamorro, Jaime
La autoevaluación es necesaria para el aprendizaje efectivo, mejorar la autoeficacia, y el desempeño académico. Dentro de los instrumentos de autoevaluación existe el Knowledge and Prior Study Inventory (KPSI) con cualidades metacognitivas. El objetivo de este trabajo fue examinar los resultados de la aplicación de KPSI en un curso de Interculturalidad y Salud y recoger la percepción de estudiantes respecto a su uso en medicina. Este fue un trabajo de naturaleza mixta. La etapa cuantitativa evaluó los puntajes del instrumento autoaplicado al inicio y al final de la asignatura, arrojando el delta promedio del curso. La etapa cualitativa exploró las percepciones del uso y utilidad en el aprendizaje del instrumento. Se realizaron dos grupos focales, se transcribieron los audios siguiendo el principio de verbatim. Se realizó análisis de contenido. La participación voluntaria y anónima. El puntaje promedio del test al inicio del curso fue de 1,7 puntos elevándose a 3,6 durante la segunda aplicación. Las preguntas con menor puntaje diferencial consideran contenidos integrados en asignaturas previas al curso, mientras que las preguntas con mayor puntaje diferencial estaban integradas por contenidos de aporte exclusivo de la asignatura. Los resultados cualitativos son claramente positivos en la percepción de aprendizaje, ayuda a identificar las fortalezas y debilidades individuales durante el proceso de aprender. Por otro lado, los invita a hacer evidente la metacognición, vale decir, cuestionarse el propio proceso de aprendizaje y lo difícil que son los procesos evaluativos en general. Las autoevaluaciones formativas con enfoque metacognitivo son positivas para el aprendizaje y se recomienda su incorporación en carreras de la salud. Es fundamental para el trabajo en el sistema de salud con la diversidad cultural de Chile que médicos desarrollen la competencia intercultural propiciada a través de la metacognición.
The ALPINE-ALMA [CII] survey: Star-formation-driven outflows and circumgalactic enrichment in the early Universe
(The European Southern Observatory (ESO), 2020) Ibar, Eduardo
We study the efficiency of galactic feedback in the early Universe by stacking the [C II] 158 µm emission in a large sample of normal star-forming galaxies at 4 < z < 6 from the ALMA Large Program to INvestigate [C II] at Early times (ALPINE) survey. Searching for typical signatures of outflows in the high-velocity tails of the stacked [C II] profile, we observe (i) deviations from a single-component Gaussian model in the combined residuals and (ii) broad emission in the stacked [C II] spectrum, with velocities of |v| . 500 km s−1 The significance of these features increases when stacking the subset of galaxies with star formation rates (SFRs) higher than the median (SFRmed = 25 M yr−1 ), thus confirming their star-formation-driven nature. The estimated mass outflow rates are comparable to the SFRs, yielding mass-loading factors of the order of unity (similarly to local star-forming galaxies), suggesting that star-formation-driven feedback may play a lesser role in quenching galaxies at z > 4. From the stacking analysis of the datacubes, we find that the combined [C II] core emission (|v| < 200 km s−1) of the higher-SFR galaxies is extended on physical sizes of ∼ 30 kpc (diameter scale), well beyond the analogous [C II] core emission of lower-SFR galaxies and the stacked far-infrared continuum. The detection of such extended metal-enriched gas, likely tracing circumgalactic gas enriched by past outflows, corroborates previous similar studies, confirming that baryon cycle and gas exchanges with the circumgalactic medium are at work in normal star-forming galaxies already at early epochs
NaCo polarimetric observations of Sz 91 transitional disc: a remarkable case of dust filtering
(Royal Astronomical Society, 2020) Mauco, Karina; Olofsson, Johan; Schreiber, Matthias R.; Bayo, Amelia; Cáceres, Claudio; Montesinos, Matías
We present polarized light observations of the transitional disc around Sz 91 acquired with VLT/NaCo at H (1.7μm) and Ks (2.2μm) bands. We resolve the disc and detect polarized emission up to ∼0.5 arcsec (∼80 au) along with a central cavity at both bands. We computed a radiative transfermodel that accounts for themain characteristics of the polarized observations. We found that the emission is best explained by small, porous grains distributed in a disc with a ∼45 au cavity. Previous ALMA observations have revealed a large sub-mm cavity (∼83 au) and extended gas emission from the innermost (<16 au) regions up to almost 400 au from the star. Dynamical clearing by multiple low-mass planets arises as the most probable mechanism for the origin of Sz 91’s peculiar structure. Using new L -band ADI observations, we can rule out companions more massive than Mp ≥ 8 MJup beyond 45 au assuming hot-start models. The disc is clearly asymmetric in polarized light along the minor axis, with the north side brighter than the south side. Differences in position angle between the disc observed at sub-mm wavelengths with ALMA and our NaCo observations were found. This suggests that the disc around Sz 91 could be highly structured. Higher signal-to-noise near-IR and sub-mm observations are needed to confirm the existence of such structures and to improve the current understanding of the origin of transitional discs.
Educação física crítica e epistemologia: uma análise comparada entre Brasil e Chile
(Universidade do Sul de Santa Catarina, 2020)
O artigo descreve, em comparação com o Brasil, a experiência de crítica do campo da Educação Física chilena a partir dos anos 1990. Em termos metodológicos, o estudo é baseado em uma revisão de artigos publicados sobre o tema no Chile. Os resultados evidenciam similaridades, mas, também, diferenças na trajetória da pedagogia crítica em ambos os países. A análise objetiva produzir uma agenda comum sobre a pedagogia crítica da Educação Física desde as realidades latino-americanas.
Cluster Difference Imaging Photometric Survey. II. TOI 837: A Young Validated Planet in IC 2602
(American Astronomical Society (Aas), 2020) Bouma, L. G.; Hartman, J. D.; Brahm, R.; Evans, P.; Collins, K. A.; Zhou, G.; Sarkis, P.; Quinn, S. N.; De Leon, J.; Livingston, J.; Bergmann, C.; Stassun, K. G.; Bhatti, W.; Winn, J. N.; Bakos, G. Á.; Abe, L.; Crouzet, N.; Dransfield, G.; Guillot, T.; Marie-Sainte, W.; Mékarnia, D.; Triaud, A. H. M. J.; Tinney, C. G.; Henning, T.; Espinoza, N.; Jordán, A.; Barbieri, M.; Nandakumar, S.; Trifonov, T.; Vines, J. I.; Vuckovic, M.; Ziegler, C.; Law, N.; Mann, A. W.; Ricker, G. R.; Vanderspek, R.; Seager, S.; Jenkins, J. M.; Burke, C. J.; Dragomir, D.; Levine, A. M.; Quintana, E. V.; Rodriguez, J. E.; Smith, J. C.; Wohler, B.
We report the discovery of TOI 837b and its validation as a transiting planet. We characterize the system using data from the NASA Transiting Exoplanet Survey Satellite mission, the ESA Gaia mission, ground-based photometry from El Sauce and ASTEP400, and spectroscopy from CHIRON, FEROS, and Veloce. We find that TOI 837 is a T = 9.9 mag G0/F9 dwarf in the southern open cluster IC 2602. The star and planet are therefore ${35}_{-5}^{+11}$ million years old. Combining the transit photometry with a prior on the stellar parameters derived from the cluster color–magnitude diagram, we find that the planet has an orbital period of $8.3\,\mathrm{days}$ and is slightly smaller than Jupiter (${R}_{{\rm{p}}}={0.77}_{-0.07}^{+0.09}\,{R}_{\mathrm{Jup}}$). From radial velocity monitoring, we limit ${M}_{{\rm{p}}}\sin i$ to less than 1.20 MJup (3σ). The transits either graze or nearly graze the stellar limb. Grazing transits are a cause for concern, as they are often indicative of astrophysical false-positive scenarios. Our follow-up data show that such scenarios are unlikely. Our combined multicolor photometry, high-resolution imaging, and radial velocities rule out hierarchical eclipsing binary scenarios. Background eclipsing binary scenarios, though limited by speckle imaging, remain a 0.2% possibility. TOI 837b is therefore a validated adolescent exoplanet. The planetary nature of the system can be confirmed or refuted through observations of the stellar obliquity and the planetary mass. Such observations may also improve our understanding of how the physical and orbital properties of exoplanets change in time.
The ALPINE-ALMA [CII] Survey: On the nature of an extremely obscured serendipitous galaxy
(Royal Astronomical Society, 2020) Ibar, Eduardo
We report the serendipitous discovery of a dust-obscured galaxy observed as part of the Atacama Large Millimeter Array (ALMA) Large Program to INvestigate [CII] at Early times (ALPINE). While this galaxy is detected both in line and continuum emissions in ALMA Band 7, it is completely dark in the observed optical/near-infrared bands and only shows a significant detection in the UltraVISTA Ks band. We discuss the nature of the observed ALMA line, that is [C II] at z ∼ 4.6 or high-J CO transitions at z ∼ 2.2. In the first case, we find a [CII]/FIR luminosity ratio of log(L[CII]/LFIR) ∼ −2.5, consistent with the average value for local star-forming galaxies (SFGs). In the second case instead, the source would lie at larger CO luminosities than those expected for local SFGs and high-z submillimetre galaxies. At both redshifts, we derive the star formation rate (SFR) from the ALMA continuum and the physical parameters of the galaxy, such as the stellar mass (M∗), by fitting its spectral energy distribution. Exploiting the results of this work, we believe that our source is a ‘main-sequence’, dusty SFG at z = 4.6 (i.e. [CII] emitter) with log(SFR/M. yr−1) ~ 1.4 and log(M*/M.) ∼ 9.9. As a support to this scenario our galaxy, if at this redshift, lies in a massive protocluster recently discovered at z ∼ 4.57, at only ∼1 proper Mpc from its centre. This work underlines the crucial role of the ALPINE survey in making a census of this class of objects, in order to unveil their contribution to the global SFR density at the end of the Reionization epoch
Height in twentieth‐century Chilean men: growth with divergence
(Springer-Verlag, 2020) Llorca‐Jaña, Manuel; Navarrete‐Montalvo, Juan; Araya‐Valenzuela, Roberto; Droller, Federico; Allende, Martina; Rivas, Javier
This article provides the frst series of Chilean adult male height for the whole of the twentieth century. The height of adult males increased by about 5.5 cm during the twentieth century, primarily during the second half of this period. This is the greatest improvement in biological welfare in Chilean history; Chilean males have never been as tall as they are today. Using a sample of around 36,371 individuals, we document the evolution of the average height of Chilean soldiers (male) born from the 1900s to the 1990s. This sample can be safely taken as a good proxy of the average height of Chilean male population for the period under study. We provide an explanation of both the main determinants of physical stature and the rapid increase in height in Chile over this period.
Towards a multi-hazard analysis of infrastructure in a seismic coast subjected to climate change, with a focus on the Chilean coastline
(The University of Queensland, 2020) Winckler Grez, Patricio
The physics of some of the most relevant climatic and geophysical drivers affecting the Chilean coasts are reviewed. Some relevant figures about the country are introduced, and recent findings and research gaps on extreme waves, meteotsunamis, storm surge, sea level rise, earthquakes and tsunamis along the country are analyzed. A discussion on how to combine these phenomena to assess the level of flooding from a multi-hazard perspective is proposed, and a conceptual framework for the integration of short-term meteorological effects, long-term climate driven hazards and geophysical drivers into a multi-hazard analysis is discussed. Finally, the identification of gaps and future research is proposed. The multi-hazard, probabilistic and nonstationary design approach proposed herein, where uncertainty is at stake, can be extended to the design of coastal infrastructure, such as the stability of breakwaters, overtopping and forces on slender elements.
TOI-481 b and TOI-892 b: Two Long-period Hot Jupiters from the Transiting Exoplanet Survey Satellite
(American Astronomical Society (Aas), 2020) Brahm, Rafael; Nielsen, Louise D.; Wittenmyer, Robert A.; Wang, Songhu; Rodriguez, Joseph E.; Espinoza, Néstor; Jones, Matías I.; Jordán, Andrés; Henning, Thomas; Hobson, Melissa; Kossakowski, Diana; Rojas, Felipe; Sarkis, Paula; Schlecker, Martin; Trifonov, Trifon; Shahaf, Sahar; Ricker, George; Vanderspek, Roland; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Addison, Brett C.; Bakos, Gáspár Á.; Bhatti, Waqas; Bayliss, Daniel; Berlind, Perry; Bieryla, Allyson; Bouchy, Francois; Bowler, Brendan P.; Briceño, César; Brown, Timothy M.; Bryant, Edward M.; Caldwell, Douglas A.; Charbonneau, David; Collins, Karen A.; Davis, Allen B.; Esquerdo, Gilbert A.; Fulton, Benjamin J.; Guerrero, Natalia M.; Henze, Christopher E.; Hogan, Aleisha; Horner, Jonathan; Huang, Chelsea X.; Irwin, Jonathan; Kane, Stephen R.; Kielkopf, John; Mann. Andrew W.; Mazeh, Tsevi; Mccormac, James; Mccully, Curtis; Mengel, Matthew W.; Mireles, Ismael; Okumura, Jack; Plavchan, Peter; Quinn, Samuel N.; Rabus, Markus; Saesen, Sophie; Schlieder, Joshua E.; Segransan, Damien; Shiao, Bernie; Shporer, Avi; Siverd, Robert J.; Stassun, Keivan G.; Suc, Vincent; Tan, Thiam-Guan; Torres, Pascal; Tinney, Chris G.; Udry, Stephane; Vanzi, Leonardo; Vezie, Michael; Vines, Jose I.; Vuckovic, Maja; Wright, Duncan J.; Yahalomi, Daniel A.; Zapata, Abner; Zhang, Hui; Ziegler, Carl
We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481 b and TOI-892 b have similar radii (0.99 ± 0.01 ${R}_{{\rm{J}}}$ and 1.07 ± 0.02 ${R}_{{\rm{J}}}$, respectively), and orbital periods (10.3311 days and 10.6266 days, respectively), but significantly different masses (1.53 ± 0.03 ${M}_{{\rm{J}}}$ versus 0.95 ± 0.07 ${M}_{{\rm{J}}}$, respectively). Both planets orbit metal-rich stars ($[\mathrm{Fe}/{\rm{H}}]$ = $+0.26\pm 0.05$ dex and $[\mathrm{Fe}/{\rm{H}}]$ = $+0.24\pm 0.05$ for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a ${M}_{\star }$ = 1.14 ± 0.02 ${M}_{\odot }$, ${R}_{\star }$ = 1.66 ± 0.02 ${R}_{\odot }$ G-type star (${T}_{\mathrm{eff}}$ = $5735\pm 72$ K), that with an age of 6.7 Gyr, is in the turn-off point of the main sequence. TOI-892 on the other hand, is a F-type dwarf star (${T}_{\mathrm{eff}}$ = $6261\pm 80$ K), which has a mass of ${M}_{\star }$ = 1.28 ± 0.03 ${M}_{\odot }$ and a radius of ${R}_{\star }$ = 1.39 ± 0.02 ${R}_{\odot }$. TOI-481 b and TOI-892 b join the scarcely populated region of transiting gas giants with orbital periods longer than 10 days, which is important to constrain theories of the formation and structure of hot Jupiters.
Lo educativo en tiempos trans-modernos: aportes para la construcción de un pensamiento educativo situado
(Universidad del Zulia, 2020) Toro Arévalo, Sergio; Peña Troncoso, Sebastián; Vega Ramírez, Javier; Moreno Doña, Alberto
El presente trabajo aborda dos aspectos fundamentales en el contexto del pensamiento educativo contemporáneo. Por una parte, se adentra en caracterizar lo educativo desde el contexto latinoamericano social, teórico e histórico, describiendo los componentes configurativos de dicho proceso a partir de Freire, Maturana, Dussel e Ilich y, por otra parte, desarrollar una síntesis de las propuestas de frontera de las ciencias de la cognición a través de una base comprensiva y activa de orientación educativa situada en el contexto de la ecología de saberes y el mosaico cultural singular de América del Sur. La base metodológica es fundamentalmente hermenéutica y epistemológica-política. El resultado es un aporte a la discusión educativa revelando, desde lo situado, los procesos de transformación educativa, tanto a nivel personal como comunitario.
Simultaneous Adsorption of 4,6-Dimethyldibenzothiophene and Quinoline over Nickel and Boron Modified Gamma-Al2O3 Adsorbent
(MDPI, 2020) Ojeda, Juan
The simultaneous adsorption of quinoline and 4,6-dimethyldibenzothiophene over adsorbents, based on alumina modified with boron and nickel under ambient temperature and pressure, was studied. The adsorbents were characterized by BET specific surface area, a potentiometric method for the determination of acid strength, electrophoretic migration, and X-ray diffraction. The results showed that the adsorbent containing nickel had better adsorption capacity than the adsorbent modified with nickel and boron, which was attributed to its greater acidity and ability to generate π-complexation between the adsorbent and the molecules. In terms of selectivity, quinoline was more adsorbed than 4,6-dimethyldibenzothiophene in all systems, due to the basic nature of quinoline. The experimental data in all cases were adjusted by three kinetic models (Yoon–Nelson, Yan and Thomas), and the regression coefficients in all models were close to one. Finally, the values of the kinetic constant obtained by the Thomas model were used to relate the adsorption capacity results. View Full-Text

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