Search

We report long-baseline interferometric observations with the CHARA Array that resolve six previously known double-lined spectroscopic binary systems in the Hyades cluster, with orbital periods ranging from 3 to 358 days: HD 27483, HD 283882, HD 26874, HD 27149, HD 30676, and HD 28545. We combine those observations with new and existing radial-velocity measurements, to infer the dynamical masses for the components as well as the orbital parallaxes. For most stars, the masses are determined to be better than 1%. Our work significantly increases the number of systems with mass determinations in the cluster. We find that, while current models of stellar evolution for the age and metallicity of the Hyades are able to reproduce the overall shape of the empirical mass–luminosity relation, they overestimate the V -band fluxes by about 0.1 mag between 0.5 and 1.4 M _⊙ . The disagreement is smaller in H , and near zero in K , and depends somewhat on the model. We also make use of the TESS light curves to estimate rotation periods for our targets, and detect numerous flares in one of them (HD 283882), estimating an average flaring rate of 0.44 events per day.

We report spectroscopic observations of vB 120 (HD 30712), a 5.7 yr astrometric–spectroscopic binary system in the Hyades cluster. We combine our radial velocities with others from the literature, and with existing speckle interferometry measurements, to derive an improved 3D orbit for the system. We infer component masses of M _1 = 1.065 ± 0.018 M _☉ and M _2 = 1.008 ± 0.016 M _☉ , and an orbital parallax of 21.86 ± 0.15 mas, which we show to be more accurate than the parallax from Gaia DR3. This is the ninth binary or multiple system in the Hyades with dynamical mass determinations, and one of the examples with the highest precision. An analysis of its spectral energy distribution yields the absolute radii of the stars, R _1 = 0.968 ± 0.012 R _☉ and R _2 = 0.878 ± 0.013 R _☉ , and effective temperatures of 5656 ± 56 K and 5489 ± 60 K for the primary and secondary, respectively. A comparison of these properties with the predictions of current stellar evolution models for the known age and metallicity of the cluster shows only minor differences.

Abstract Insulin‐like growth factor (IGF) binding proteins (IGFBPs) are a family of growth factor modifiers, some of which are known to be independently associated with pulmonary arterial hypertension (PAH) survival. IGF factor binding protein 7 (IGFBP7) is a unique low‐affinity IGFBP that, independent of IGF, stimulates prostacyclin production. This study proposed to establish associations between IGFBP7 and PAH severity and survival, using enrollment and longitudinal samples. Serum IGFBP7 levels were significantly elevated in patients with PAH compared to controls. After adjusting for age and sex, logarithmic increases in IGFBP7 were associated with a 20 m shorter six‐minute walk distance (6MWD; p

Abstract Background COVID-19 infection, especially in cases with pneumonia, is associated with a high rate of pulmonary embolism (PE). In patients with contraindications for CT pulmonary angiography (CTPA) or non-diagnostic CTPA, perfusion single-photon emission computed tomography/computed tomography (Q-SPECT/CT) is a diagnostic alternative. The goal of this study is to develop a radiomic diagnostic system to detect PE based only on the analysis of Q-SPECT/CT scans. Methods This radiomic diagnostic system is based on a local analysis of Q-SPECT/CT volumes that includes both CT and Q-SPECT values for each volume point. We present a combined approach that uses radiomic features extracted from each scan as input into a fully connected classification neural network that optimizes a weighted cross-entropy loss trained to discriminate between three different types of image patterns (pixel sample level): healthy lungs (control group), PE and pneumonia. Four types of models using different configuration of parameters were tested. Results The proposed radiomic diagnostic system was trained on 20 patients (4,927 sets of samples of three types of image patterns) and validated in a group of 39 patients (4,410 sets of samples of three types of image patterns). In the training group, COVID-19 infection corresponded to 45% of the cases and 51.28% in the test group. In the test group, the best model for determining different types of image patterns with PE presented a sensitivity, specificity, positive predictive value and negative predictive value of 75.1%, 98.2%, 88.9% and 95.4%, respectively. The best model for detecting pneumonia presented a sensitivity, specificity, positive predictive value and negative predictive value of 94.1%, 93.6%, 85.2% and 97.6%, respectively. The area under the curve (AUC) was 0.92 for PE and 0.91 for pneumonia. When the results obtained at the pixel sample level are aggregated into regions of interest, the sensitivity of the PE increases to 85%, and all metrics improve for pneumonia. Conclusion This radiomic diagnostic system was able to identify the different lung imaging patterns and is a first step toward a comprehensive intelligent radiomic system to optimize the diagnosis of PE by Q-SPECT/CT. Highlights Artificial intelligence applied to Q-SPECT/CT is a diagnostic option in patients with contraindications to CTPA or a non-diagnostic test in times of COVID-19.

Nowadays, global climate change is likely the most compelling problem mankind is facing. In this scenario, decarbonisation of the chemical industry is one of the global challenges that the scientific community needs to address in the immediate future. Catalysis and catalytic processes are called to play a decisive role in the transition to a more sustainable and low-carbon future. This critical review analyses the unique advantages of structured reactors (isothermicity, a wide range of residence times availability, complex geometries) with the multifunctional design of efficient catalysts to synthesise chemicals using CO2 and renewable H2 in a Power-to-X (PTX) strategy. Fine-chemistry synthetic methods and advanced in situ/operando techniques are essential to elucidate the changes of the catalysts during the studied reaction, thus gathering fundamental information about the active species and reaction mechanisms. Such information becomes crucial to refine the catalyst’s formulation and boost the reaction’s performance. On the other hand, reactors architecture allows flow pattern and temperature control, the management of strong thermal effects and the incorporation of specifically designed materials as catalytically active phases are expected to significantly contribute to the advance in the valorisation of CO2 in the form of high added-value products. From a general perspective, this paper aims to update the state of the art in Carbon Capture and Utilisation (CCU) and PTX concepts with emphasis on processes involving the transformation of CO2 into targeted fuels and platform chemicals, combining innovation from the point of view of both structured reactor design and multifunctional catalysts development.

Abstract Proteomic analysis of patients with pulmonary arterial hypertension (PAH) has demonstrated significant abnormalities in the insulin‐like growth factor axis (IGF). This study proposed to establish associations between a specific binding protein, insulin‐like growth factor binding protein 4 (IGFBP4), and PAH severity as well as survival across varying study cohorts. In all cohorts studied, serum IGFBP4 levels were significantly elevated in PAH compared to controls (p

We studied 89 A- and F-type members of the Pleiades open cluster, including five escaped members. We measured projected rotational velocities ( $v\sin i$ ) for 49 stars and confirmed that stellar rotation causes a broadening of the main sequence in the color–magnitude diagram. Using time-series photometry from NASA’s TESS Mission (plus one star observed by Kepler/K2), we detected δ Scuti pulsations in 36 stars. The fraction of Pleiades stars in the middle of the instability strip that pulsate is unusually high (over 80%), and their range of effective temperatures agrees well with theoretical models. On the other hand, the characteristics of the pulsation spectra are varied and do not correlate with stellar temperature, calling into question the existence of a useful ${\nu }_{\max }$ relation for δ Scutis, at least for young main-sequence stars. By including δ Scuti stars observed in the Kepler field, we show that the instability strip is shifted to the red with increasing distance by interstellar reddening. Overall, this work demonstrates the power of combining observations with Gaia and TESS for studying pulsating stars in open clusters.

Ultraviolet spectra were taken of 25 detached eclipsing binaries (DEBs) with spectral types O, B, and early A with the International Ultraviolet Explorer satellite in the 1150–1900 Å region. The spectra were compared with BOSZ model atmospheres. The composite spectra of the DEBs were modeled by a combination of models representing the hot and cool components, and the temperatures of the hottest components of the systems were determined. From these temperatures a direct mass–temperature relation was obtained for stars close to the main sequence with solar metallicity for B and early A stars: log M/M _⊙ = −5.90 ± 0.27 + (1.56 ± 0.07) × log T . This relation allows a mass to be inferred for comparable stars from an ultraviolet spectrum. The five chemically peculiar Am stars in the sample have larger radii than normal A stars of the same mass.

We report the discovery of 2M0056–08 as an equal-mass eclipsing binary (EB), comprising two red straggler stars (RSSs) with an orbital period of 33.9 days. Both stars have masses of ≈1.419 M _⊙ , identical to within 0.2%. Both stars appear to be in the early red-giant phase of evolution; however, they are far displaced to cooler temperatures and lower luminosities compared to standard stellar models. The broadband spectral energy distribution shows NUV excess and X-ray emission, which is consistent with chromospheric and coronal emission from magnetically active stars. Indeed, the stars rotate more rapidly than typical red giants and they evince light-curve modulations due to spots. These modulations also reveal the stars to be rotating synchronously with one another. There is evidence for excess FUV emission and long-term modulations in radial velocities, although it is not clear if they are also attributable to magnetic activity or if they reveal a tertiary companion. Stellar evolution models that are modified to account for the effects of spots can reproduce the observed radii and temperatures of the RSSs. If the system possesses a white dwarf tertiary, then mass-transfer scenarios could explain the manner by which the stars came to possess such remarkably identical masses and by which they came to be synchronized. However, if the stars are presumed to have been formed as identical twins and they then managed to become tidally synchronized as they evolved toward the red-giant branch, then all of the features of the system can be explained via activity effects without requiring a complex dynamical history.

We present the discovery and characterization of HIP 33609 b, a transiting warm brown dwarf orbiting a late B star, discovered by NASA's Transiting Exoplanet Survey Satellite as TOI-588 b. HIP 33609 b is a large ( R _b = ${1.580}_{-0.070}^{+0.074}$ R _J ) brown dwarf on a highly eccentric ( e = ${0.560}_{-0.031}^{+0.029}$ ) orbit with a 39 days period. The host star is a bright ( V = 7.3 mag), T _eff = 10,400 ${}_{-660}^{+800}$ K star with a mass of M _* = ${2.383}_{-0.095}^{+0.10}$ M _⊙ and radius of R _* = ${1.863}_{-0.082}^{+0.087}$ R _⊙ , making it the hottest transiting brown dwarf host star discovered to date. We obtained radial velocity measurements from the CHIRON spectrograph confirming the companion's mass of M _b = ${68.0}_{-7.1}^{+7.4}$ M _J as well as the host star's rotation rate ( $v\sin {i}_{* }=55.6\pm 1.8$ km s ^−1 ). We also present the discovery of a new comoving group of stars, designated as MELANGE-6, and determine that HIP 33609 is a member. We use a combination of rotation periods and isochrone models fit to the cluster members to estimate an age of 150 ± 25 Myr. With a measured mass, radius, and age, HIP 33609 b becomes a benchmark for substellar evolutionary models.

We present a validation of a long-period ( ${91.68278}_{-0.00041}^{+0.00032}$ days) transiting sub-Neptune planet, TOI-1221 b (TIC 349095149.01), around a Sun-like ( m _V = 10.5) star. This is one of the few known exoplanets with a period >50 days, and belongs to the even smaller subset of which have bright enough hosts for detailed spectroscopic follow-up. We combine Transiting Exoplanet Survey Satellite light curves and ground-based time-series photometry from the Perth Exoplanet Survey Telescope (0.3 m) and Las Cumbres Observatory global telescope network (1.0 m) to analyze the transit signals and rule out nearby stars as potential false-positive sources. High-contrast imaging from the Southern Astrophysical Research Telescope and Gemini/Zorro rule out nearby stellar contaminants. Reconnaissance spectroscopy from CHIRON sets a planetary scale upper mass limit on the transiting object (1.1 and 3.5 M _Jup at 1 σ and 3 σ , respectively) and shows no sign of a spectroscopic binary companion. We determine a planetary radius of ${R}_{{\rm{p}}}={2.91}_{-0.12}^{+0.13}{R}_{\oplus }$ , placing it in the sub-Neptune regime. With a stellar insolation of $S={6.06}_{-0.77}^{+0.85}\ {S}_{\oplus }$ , we calculate a moderate equilibrium temperature of T _eq = 440 K, assuming no albedo and perfect heat redistribution. We find a false-positive probability from the TRICERATOPS tool of FPP = 0.0014 ± 0.0003 as well as other qualitative and quantitative evidence to support the statistical validation of TOI-1221 b. We find significant evidence (>5 σ ) of oscillatory transit timing variations, likely indicative of an additional nontransiting planet.

Populating the exoplanet mass–radius diagram in order to identify the underlying relationship that governs planet composition is driving an interdisciplinary effort within the exoplanet community. The discovery of hot super-Earths—a high-temperature, short-period subset of the super-Earth planet population—has presented many unresolved questions concerning the formation, evolution, and composition of rocky planets. We report the discovery of a transiting, ultra-short-period hot super-Earth orbiting TOI-1075 (TIC351601843), a nearby ( d = 61.4 pc) late-K/early-M-dwarf star, using data from the Transiting Exoplanet Survey Satellite. The newly discovered planet has a radius of 1.791 ${}_{-0.081}^{+0.116}$ R _⊕ and an orbital period of 0.605 day (14.5 hr). We precisely measure the planet mass to be 9.95 ${}_{-1.30}^{+1.36}$ M _⊕ using radial velocity measurements obtained with the Planet Finder Spectrograph mounted on the Magellan II telescope. Our radial velocity data also show a long-term trend, suggesting an additional planet in the system. While TOI-1075 b is expected to have a substantial H/He atmosphere given its size relative to the radius gap, its high density ( ${9.32}_{-1.85}^{+2.05}$ g cm ^−3 ) is likely inconsistent with this possibility. We explore TOI-1075 b’s location relative to the M-dwarf radius valley, evaluate the planet’s prospects for atmospheric characterization, and discuss potential planet formation mechanisms. Studying the TOI-1075 system in the broader context of ultra-short-period planetary systems is necessary for testing planet formation and evolution theories and density-enhancing mechanisms and for future atmospheric and surface characterization studies via emission spectroscopy with the JWST.

The radius valley carries implications for how the atmospheres of small planets form and evolve, but this feature is visible only with highly precise characterizations of many small planets. We present the characterization of nine planets and one planet candidate with both NASA TESS and ESA CHEOPS observations, which adds to the overall population of planets bordering the radius valley. While five of our planets—TOI 118 b, TOI 262 b, TOI 455 b, TOI 560 b, and TOI 562 b—have already been published, we vet and validate transit signals as planetary using follow-up observations for four new TESS planets, including TOI 198 b, TOI 244 b, TOI 444 b, and TOI 470 b. While a three times increase in primary mirror size should mean that one CHEOPS transit yields an equivalent model uncertainty in transit depth as about nine TESS transits in the case that the star is equally as bright in both bands, we find that our CHEOPS transits typically yield uncertainties equivalent to between two and 12 TESS transits, averaging 5.9 equivalent transits. Therefore, we find that while our fits to CHEOPS transits provide overall lower uncertainties on transit depth and better precision relative to fits to TESS transits, our uncertainties for these fits do not always match expected predictions given photon-limited noise. We find no correlations between number of equivalent transits and any physical parameters, indicating that this behavior is not strictly systematic, but rather might be due to other factors such as in-transit gaps during CHEOPS visits or nonhomogeneous detrending of CHEOPS light curves.

The efficiency of lung cancer screening for reducing mortality is hindered by the high rate of false positives. Artificial intelligence applied to radiomics could help to early discard benign cases from the analysis of CT scans. The available amount of data and the fact that benign cases are a minority, constitutes a main challenge for the successful use of state of the art methods (like deep learning), which can be biased, over-fitted and lack of clinical reproducibility. We present an hybrid approach combining the potential of radiomic features to characterize nodules in CT scans and the generalization of the feed forward networks. In order to obtain maximal reproducibility with minimal training data, we propose an embedding of nodules based on the statistical significance of radiomic features for malignancy detection. This representation space of lesions is the input to a feed forward network, which architecture and hyperparameters are optimized using own-defined metrics of the diagnostic power of the whole system. Results of the best model on an independent set of patients achieve 100% of sensitivity and 83% of specificity (AUC = 0.94) for malignancy detection.

Main-sequence stars with convective envelopes often appear larger and cooler than predicted by standard models of stellar evolution for their measured masses. This is believed to be caused by stellar activity. In a recent study, accurate measurements were published for the K-type components of the 1.62-day detached eclipsing binary EPIC 219511354, showing the radii and temperatures for both stars to be affected by these discrepancies. This is a rare example of a system in which the age and chemical composition are known, by virtue of being a member of the well-studied open cluster Ruprecht 147 (age~3 Gyr, [Fe/H] = +0.10). Here, we report a detailed study of this system with nonstandard models incorporating magnetic inhibition of convection. We show that these calculations are able to reproduce the observations largely within their uncertainties, providing robust estimates of the strength of the magnetic fields on both stars: 1600 ± 130 G and 1830 ± 150 G for the primary and secondary, respectively. Empirical estimates of the magnetic field strengths based on the measured X-ray luminosity of the system are roughly consistent with these predictions, supporting this mechanism as a possible explanation for the radius and temperature discrepancies.

Rye (Secale cereale ssp. cereale L.) is a secondary domesticate, considered to have originated as a weed in wheat fields and to have developed traits of domestication by evolving similar physiological and morphological characteristics to those of wheat. Although it migrated into Europe as a weed possessing domestication traits, it became one of the most significant crops grown in large parts of Europe from the medieval period onward. Within the modern borders of Germany, rye was grown using at least two divergent cultivation practices: eternal rye monoculture and three-field rotation. The straw of rye was used to produce Wellerhölzer, which are construction components in traditional half-timbered houses that have enabled a desiccated preservation of the plant remains. In order to assess the impact of cultivation practices, local environmental conditions and genetic variation on the genetic diversification of rye, we seek to integrate well-established archaeobotanical methods with aDNA sequencing of desiccated plant remains obtained from Wellerhölzer from Germany. In the current contribution, we present a proof of concept, based on the analysis of plant remains from a Wellerholz from the Old Town Hall of Göttingen. We use arable weed ecology to reconstruct cultivation practices and local environmental conditions and present a phylogenetic analysis based on targeted loci of the chloroplast and nuclear genome. Our results emphasise that the study of desiccated remains of plants from Wellerhölzer offer a unique opportunity for an integration of archaeobotanical reconstructions of cultivation practices and local environment and the sequencing of aDNA.

El presente artículo expone los resultados de un trabajo inicialmente más amplio, ligado al estudio de las políticas públicas educativas en la transición del Estado por el periodo de 1989-2012, agregándose como continuidad de ese estudio, haciendo referencia a una valoración de las políticas hacia las instituciones de educación del gobierno del Lic. Felipe Calderón H., 2006-2012 en México. Pero sobre todo, por ahora nos centramos en la Reforma Educativa 2012-2013 como una de las primeras iniciativas que presentó el Ejecutivo federal proveniente del Partido Revolucionario Institucional (PRI) del actual sexenio 2012-2018, en sus primeros 100 días de gobierno. El análisis y los resultados del presente trabajo, incluyeron una revisión de la iniciativa presidencial, entrevistas a personajes clave, diálogos con representantes de senadores y diputados e integrantes de la Coordinadora de Trabajadores de la Educación. El objetivo consiste en conocer la propuesta gubernamental de Reforma Educativa, con la finalidad de arribar a políticas de reforma educativa del Estado y del gobierno federal, así como la apreciación de los sujetos sociales y actores educativos frente a dicha política como alternativa al proyecto gubernamental. La iniciativa de reforma Educativa y el proceso de discusión y aprobación en una coyuntura política de casi dos años, de diciembre 2012 a octubre de 2013, se aborda en tres momentos: primero, un análisis técnico; segundo, un análisis político; y tercero, un conjunto de alternativas y preguntas que se deben resolver para seguir adelante con las reflexiones en torno al futuro de la Reforma Educativa en cuestión.

This article discusses the issue of the environment under the conditions of extreme destruction of the planet as a result of sociocultural evolution, and the crisis of knowledge that derives from man’s non-adaptation to nature. Consequently, it poses some theoretical reflections in order to achieve an integral transformation that is both social and individual, on the path to a civilizational transition that requires overcoming the fundamental concepts of current socio-environmental reality. It therefore proposes some strategies for the construction of an environmental epistemology in that direction, which entails restructuring educational processes from a perspective based on diversity and, through the production of new social knowledge, surpassing a solitary view of reality in order to achieve one that is shared.

Climate change is increasing the frequency and severity of marine heatwaves. A recent extreme warming event (2014–2016) of unprecedented magnitude and duration in the California Current System allowed us to evaluate the response of the kelp forest community near its southern (warm) distribution limit. We obtained sea surface temperatures for the northern Pacific of Baja California, Mexico, and collected kelp forest community data at three islands, before and after the warming event. The warming was the most intense and persistent event observed to date, with low-pass anomalies 1°C warmer than the previous extremes during the 1982–1984 and 1997–1998 El Niños. The period between 2014 and 2017 accounted for ∼50% of marine heatwaves days in the past 37 years, with the highest maximum temperature intensities peaking at 5.9°C above average temperatures for the period. We found significant declines in the number of Macrocystis pyrifera individuals, except at the northernmost island, and corresponding declines in the number of fronds per kelp individual. We also found significant changes in the community structure associated with the kelp beds: half of the fish and invertebrate species disappeared after the marine heatwaves, species with warmer affinities appeared or increased their abundance, and introduced algae, previously absent, appeared at all islands. Changes in subcanopy and understory algal assemblages were also evident; however, the response varied among islands. These results suggest that the effect of global warming can be more apparent in sensitive species, such as sessile invertebrates, and that warming-related impacts have the potential to facilitate the establishment of tropical and invasive species.

En el presente artículo, se debate sobre la necesidad de construir un nuevo paradigma educativo en torno a la pedagogía ambiental, considerándola como parte de los cambios requeridos en el mundo para enfrentar la crisis de la civilización. Para lograr lo anterior, el punto de partida es el debate sobre la articulación de las disciplinas en una metadisciplina ; y la integración del conocimiento científico con el “no científico” en el marco de la pérdida de vigencia del viejo modelo positi - vista. De esta forma, se ubica el proceso de enseñanza-aprendizaje desde la perspectiva de la complejidad socioambiental. Posteriormente, se discute los fundamentos de la pedagogía ambiental a través de la conversión del paradigma científico en nuevo conocimiento popular, lo cual debe fincarse en la educación para la compatibilidad-sustentabilidad, mediante la generación de diálogos multidimensionales, y transitar hacia un nuevo modelo educativo. Se concluye discutiendo el necesario impulso, en las comunidades, del aprendizaje socioambiental como ancla de dicha pedagogía ambiental.

It is acknowledged that an effective path to globally protect marine ecosystems is through the establishment of eco-regional scale networks of MPAs spanning across national frontiers. In this work we aimed to plan for regionally feasible networks of MPAs that can be ecologically linked with an existing one in a transboundary context. We illustrate our exercise in the Ensenadian eco-region, a shared marine ecosystem between the south of California, United States of America (USA), and the north of Baja California, Mexico; where conservation actions differ across the border. In the USA, California recently established a network of MPAs through the Marine Life Protection Act (MLPA), while in Mexico: Baja California lacks a network of MPAs or a marine spatial planning effort to establish it. We generated four different scenarios with Marxan by integrating different ecological, social, and management considerations (habitat representation, opportunity costs, habitat condition, and enforcement costs). To do so, we characterized and collected biophysical and socio-economic information for Baja California and developed novel approaches to quantify and incorporate some of these considerations. We were able to design feasible networks of MPAs in Baja California that are ecologically linked with California's network (met between 78.5 and 84.4% of the MLPA guidelines) and that would represent a low cost for fishers and aquaculture investors. We found that when multiple considerations are integrated more priority areas for conservation emerge. For our region, human distribution presents a strong gradient from north to south and resulted to be an important factor for the spatial arrangement of the priority areas. This work shows how, despite the constraints of a data-poor area, the available conservation principles, mapping, and planning tools can still be used to generate spatial conservation plans in a transboundary context.

Enero-Junio 2014 39 Resumen / Abstract La tortilla de maíz es un alimento funda- mental en la dieta de los mexicanos. Sin embargo, su demanda disminuyó 36.7% de 1996 a 2008. El objetivo de este estu- dio fue identifi car y medir por estratos de ingreso los principales factores económi- cos que afectaron la demanda de este ali- mento en México. Para ello, se estimaron tres modelos uniecuacionales del compor- tamiento de su demanda utilizando datos de ENIGH y Banxico. Los resultados indi- can una respuesta inelástica de los consu- midores a los cambios en el precio de la tortilla, el gasto y los bienes relacionados; por lo que la tortilla se comporta como un bien normal inferior para los estratos re- feridos. Asimismo, el frijol, el porcino, el bovino, la salsa (chile, tomate y cebolla) y el queso funcionan como complementos de la tortilla; y el pan, el arroz y la papa como sus sustitutos.

En este texto se realiza una reflexión en torno a la relación de la guerra con la economía (de la que emerge la economía de guerra permanente) en el plano teórico, así como sus más graves consecuencias productivas, financieras y socioambientales desde el punto de vista de la economía política, para así poder comprender su vínculo con la expansión del consumo improductivo, que representa un factor fundamental en el funcionamiento del capitalismo contemporáneo y está detrás de la crisis sistémica actual. Ésta no podrá ser remontada simplemente con más gasto público dirigido al rescate de megaempresas y bancos (a costa del bienestar social), ya que su origen está en los desequilibrios entre los sectores básicos de la reproducción del capital global, los cuales tienen que ver con el consumismo y el armamentismo, que constituyen la clave del modelo de acumulación hegemónico.

This article provides an overview of the important aspects to be considered within learning organizations focused on continuous learning at the individual, group and organizational level, in order to develop the necessary competences and face their environment in a competitive way. This article aims to present several topics covered, from its introduction and identification of knowledge attributes and learning, until what is an intelligent organization, the structural design to be adopted as well as the skills of management to be implemented. The intention of this paper is to contribute to the stock of current theoretical information that serves as a reference for the practical research of the academics.Este artículo es un estudio de los aspectos que deben ser considerados dentro de las organizaciones inteligentes cuyo enfoque se centra en el aprendizaje constante (tanto individual como organizacional) como una estrategia para desarrollar las competencias que les permitan enfrentar el entorno de una manera competitiva. Al exponer dichas temáticas, desde la presentación e identificación de las características del conocimiento y el aprendizaje dentro de una organización inteligente, hasta el diseño estructural a adoptar y las habilidades de gestión gerencial a ejecutar, nuestra intención es contribuir a la aplicación del conocimiento dentro del ámbito de la gestión empresarial.

En este artículo se realiza un acercamiento teórico-metodológico a una de las explicaciones actuales en torno al desarrollo sustentable, específicamente urbano: el denominado enfoque territorial, tomando como referente el caso paradigmático de la Zona Metropolitana del Valle de México (zmvm). El propósito fundamental es reflexionar sobre las interconexiones analítico-cognoscitivas que implica un nuevo tipo de desarrollo y, al mismo tiempo, analizar las posibles consecuencias prácticas a que conduce; así como realizar un balance a partir de sus aportaciones y limitaciones. Para ello se estudia en general el tema del enfoque territorial; y luego se consideran las diferencias en los ámbitos rural y urbano. De esa forma, se formulan sólo algunas reflexiones en relación con su alcance en la zmvm, y se destacan las dificultades a que conlleva dicho enfoque, que aquí se considera insuficiente para contribuir a la sustentabilidad urbana.

Sin resumen.

Se analiza la investigación mundial sobre terapias cuerpo-mente, a través de los artículos publicados en revistas científicas sobre tres disciplinas orientales: yoga, tai chi y qi gong, y tres prácticas o procedimientos: la meditación, los ejercicios respiratorios y la relajación. La búsqueda bibliográfica se realizó en la base de datos Scopus y se limitó a las áreas biomédicas y al periodo 2006-2010. Se examinaron 2.363 artículos de 959 revistas diferentes, publicados por 6.583 autores pertenecientes a 2.162 instituciones de 65 países. Se calcularon los indicadores de productividad e impacto científico de las instituciones, países y áreas temáticas, así como la colaboración entre autores e instituciones. Se observa un aumento progresivo de las publicaciones, especialmente sobre el yoga y la meditación, sobre todo de las universidades de los EE.UU., India y China con una marcada concentración en las áreas de medicina interna, salud mental y oncología.

The PISA tests applied by OECD in 2012 had a strong impact in Colombia because of the low scores obtained by students . The news had more coverage in the press. In order to establish how they can shape public opinion on the subject because of the manner and direction in which they were addressed, were analyzed news , editorials, opinion columns and letters from readers (total 39 information units) appeared in two Colombian daily newspapers in two and a half months. Recognizing the evaluation as a social fact , the analysis focused around : quality of information sources used , breadth of perspective on the evidence by reference to the evidence and formulate action alternatives . The basic conclusions are : the sources of information to give opinion are very limited, they aren´t criticized and the focus is on the scores ; these show a very negative picture that is extended to all the country's education ; teachers are largely responsible for the failure. The opinion that the media contribute to form is negative.

The United States and Mexico share the Southern California Bight (SCB) ecosystem in the Northeast Pacific Ocean where marine wildlife and habitats historically have been disturbed by human activities. Within this ecosystem, forests of the giant kelp Macrocystis pyrifera are critical habitats that sustain diverse biological assemblages and important fishery species. We studied patterns of temporal and spatial variability within the benthic communities of five transboundary kelp forests in California (USA) and Baja California (Mexico) over a fouryear period that included a moderate El Niño event. While the benthic marine communities shared some species, they varied significantly in community structure from each other, and the degree of dissimilarity was not related to the geographic distances among the studied habitats. Rather, species richness was significantly related to local substratum rugosity, suggesting it could be used as a proxy of relative benthic biological diversity. Temporal changes in the benthic assemblages were not consistent across all forests, and contrary to observations made during previous El Niño events in the SCB, the benthic communities did not change significantly following the 2009–2010 El Niño. Such an unexpected community response may be explained by the fact that the 2009–2010 El Niño was linked to the Modoki phenomenon, where warm sea surface temperature is focused in the central equatorial Pacific and not in the eastern Pacific Ocean. We propose that long-term conservation efforts should incorporate this ecological knowledge to support science-based decisions, binational coordination of policies, and coherent management practices including the design of transboundary conservation networks as spatial management tools for the protection, conservation, and/or restoration of the SCB ecosystem.

En este artículo se realiza un acercamiento teórico-metodológico a una de las explicaciones actuales en torno al desarrollo sustentable, específicamente urbano: el denominado enfoque territorial, tomando como referente el caso paradigmático de la Zona Metropolitana del Valle de México (zmvm). El propósito fundamental es reflexionar sobre las interconexiones analítico-cognoscitivas que implica un nuevo tipo de desarrollo y, al mismo tiempo, analizar las posibles consecuencias prácticas a que conduce; así como realizar un balance a partir de sus aportaciones y limitaciones. Para ello se estudia en general el tema del enfoque territorial; y luego se consideran las diferencias en los ámbitos rural y urbano. De esa forma, se formulan sólo algunas reflexiones en relación con su alcance en la zmvm, y se destacan las dificultades a que conlleva dicho enfoque, que aquí se considera insuficiente para contribuir a la sustentabilidad urbana.

En este trabajo se presenta un enfoque basado en competencias de sistemas multiagentes como fundamento de la enseñanza de tópicos avanzados en Inteligencia Artificial. La metodología fue implementada en la materia optativa Robótica Cognitiva con alumnos del 5to. año de la carrera Licenciatura en Ciencias de la Computación, de la Universidad Nacional del Comahue, en un dominio que es conocido y divertido: el fútbol. Los campeonatos que se realizan entre los diferentes equipos permiten que los estudiantes evalúen y comparen los resultados. La motivación que se logra es fundamental para despertar interés en el estudio de técnicas la Inteligencia Artificial y en la investigación en general. Se presentan la experiencia desarrollada, un análisis de la metodología y el impacto en el dominio académico y de investigación.

Sin resumen.

Abstract The main challenge faced by many mechanical engineering educators is the implementation of real solutions during their courses. One alternative can be a realistic case study, where the students can be engaged in the development and analysis process currently applied in the industry. This kind of teaching process not only can be used to improve the quality of teaching‐learning process but also the students can have opportunities to solve real engineering problem. Therefore, this paper reports a realistic case implemented in mechanical engineering courses given in bachelor's and master's degrees. The component under evaluation has been selected considering the student's interest, this criterion was also taken to involve several students into a real project process to their learning development. The same problem was solved during an academic semester, it was solved using different approaches and student's abilities. This procedure can be replicated for students and teachers by following steps. The first step in this process was to describe the theoretical basis for modal analysis to understand how it was structured a numerical finite element model. This model was then solved and simulated using Hypermesh, Optistruct, and HyperView software to obtain numerical modal parameters. On the other, hand, the experimental modal parameters were obtained using a three‐dimensional scanning vibrometer on 60 samples. It is well noted that the implementation of engineering software commonly used at the industry would increase students' confidence. This allows students to perform real problem‐solving activities to develop outcomes as establish goals, plan task, meet deadlines. These activities are extremely important to the actual automotive industry. Therefore, this paper shows an engineering solution process to provide a learning alternative to teach the modal finite method solutions correlation with experimental solutions.

Wood products used in outdoor applications can be degraded by xylophage organisms. For this reason, such products require treatments based on biocides in order to delay their service life. This brings troubles of its own due to the inherent toxicity of these treatments towards humans and the environment. Therefore, it is imperative to find less-toxic natural preservatives. In this context, this work deals with the evaluation of the fungitoxic effect of raw extracts obtained from three types of agroindustrial waste materials: bark of Quercus laeta spp., the cob of Zea mays, and the leaves of Agave tequilana Weber Blue variety. Extracts were incorporated into the test wood Alnus acuminata (Aile wood) via a full-cell process. Bark extracts provided excellent protection against the attack of Trametes versicolor (L. ex. Fr.) Pilát, improving the decay resistance of Aile wood from being nonresistant to resistant. Also, bark extracts from Q. laeta showed less leaching than the other extracts.

This study aimed to analyze the ways in which sixth-grade elementary school students reflected on historical causality through the establishment of relationships resulting from a reading activity. A qualitative exploratory study was conducted involving nine sixth-grade students from Guanajuato, Mexico. Individual interviews were conducted using a semi-structured interview protocol aimed at delving into the causal interpretations suggested by the students. The results revealed six modalities of causal relationship, four of which contained temporal features, one contained semantic and pragmatic elements, and one was constructed considering the placement of events in the text. The narrative and discursive aspects of the causal relationships established by the students are discussed, as well as some reflections on approaching history through reading texts.

In this work, cellulose nanocrystals (CNCs), bleached cellulose nanofibers (bCNFs), and unbleached cellulose nanofibers (ubCNFs) isolated by acid hydrolysis from Agave tequilana Weber var. Azul bagasse, an agro-waste from the tequila industry, were used as reinforcements in a thermoplastic starch matrix to obtain environmentally friendly materials that can substitute contaminant polymers. A robust characterization of starting materials and biocomposites was carried out. Biocomposite mechanical, thermal, and antibacterial properties were evaluated, as well as color, crystallinity, morphology, rugosity, lateral texture, electrical conductivity, chemical identity, solubility, and water vapor permeability. Pulp fibers and nanocelluloses were analyzed via SEM, TEM, and AFM. The water vapor permeability (WVP) decreased by up to 20.69% with the presence of CNCs. The solubility decreases with the presence of CNFs and CNCs. The addition of CNCs and CNFs increased the tensile strength and Young’s modulus and decreased the elongation at break. Biocomposites prepared with ubCNF showed the best tensile mechanical properties due to a better adhesion with the matrix. Images of bCNF-based biocomposites demonstrated that bCNFs are good reinforcing agents as the fibers were dispersed within the starch film and embedded within the matrix. Roughness increased with CNF content and decreased with CNC content. Films with CNCs did not show bacterial growth for Staphylococcus aureus and Escherichia coli. This study offers a new theoretical basis since it demonstrates that different proportions of bleached or unbleached nanofibers and nanocrystals can improve the properties of starch films.

Objetivo: Determinar las características clínicas y epidemiológicas de la estenosis hipertrófica de píloro en un hospital de lima Perú. Materiales y métodos: Se realizo un estudio descriptivo, retrospectivo correspondiente de los años 2013 al 2019, en el servicio de cirugía pediátrica del hospital docente madre niño “San Bartolomé”. En donde recolectamos los datos a través de las historias clínicas con diagnóstico estenosis hipertrófica de píloro. Resultados: Se obtuvieron un total de 59 pacientes, de los cuales 79.7% fueron varones, 68.4% primogénitos, con una media de edad de 31.3 +/- 13.6 días de nacido. 100% presento vómitos, 44.1% reptaciones y solo 35.6% presento oliva pilórica palpable. Tiempo quirúrgico promedio 51.39 +/- 19.1 minutos, estancia hospitalaria promedio de 6.35 +/- 6.56 días, se presentó complicaciones en un 13.6% y una mortalidad de 3.4%. Conclusiones: La importancia del inicio precoz de la vía oral, así como el manejo postquirúrgico es importante en estos pacientes para poder disminuir su estancia hospitalaria, se debe de tomar en cuenta el manejo del paciente postquirúrgico y sus complicaciones respiratorias.

In this work, a photo-polymerization route was used to obtain potassium acrylate-co-acrylamide hydrogels with enhanced mechanical properties, well-defined microstructures in the dry state, and unique meso- and macrostructures in the hydrated state. The properties of the hydrogels depended on the concentration of the crosslinking agent. Mechanical properties, swelling capacity, and morphology were analyzed, showing a well-defined transition at a critical concentration of the crosslinker. In terms of morphology, shape-evolving surface patterns appeared at different scales during swelling. These surface structures had a noticeable influence on the mechanical properties. Hydrogels with structures exhibited better mechanical properties compared to unstructured hydrogels. The critical crosslinking concentration reported in this work (using glycerol diacrylate) is a reference point for the future preparation of multistructured acrylic hydrogel with enhanced properties.

The sum of lognormal variables has been a topic of interest in several fields of research such as engineering, biology and finance, among others. For example, in the field of telecommunications, the aggregate interference of radio frequency signals is modeled as a sum of lognormal variables. To date, there is no closed expression for the probability distribution function (PDF) of this sum. Several authors have proposed approximations for this PDF, with which they calculate the mean and variance. However, each method has limitations in its range of parameters for mean, variance and number of random variables to be added. In other cases, long approximations as power series are used, which makes the analytical treatment impractical and reduces the computational performance of numerical operations. This paper shows an alternative method for calculating the mean and variance of the sum of lognormal random variables from a computational performance approach. Our method has been evaluated extensively by Monte Carlo simulations. As a result, this method is computationally efficient and yields a low approximation error computation for a wide range of mean values, variances and number of random variables.

Some plants have great resistance against herbivores, invertebrates, insects, bacteria, and fungi. This resistance is mostly present in plants containing alkaloids, which are the substances responsible for giving them defensive properties. The genus Datura contains tropane alkaloids and all plants from this genus have defensive properties. In this work, we report the toxic effect against fungi of Datura stramonium extracts, obtained by the Petri dish method. The extraction solvents were water, ethanol, 2-propanol, n-butanol, propanone, butanone, 3-methyl-2-pentanone, dichloromethane, xylene, and toluene. The test fungi were Trametes versicolor (L. ex. Fr) Pilát and Rhodonia placenta (Fr.) Niemelä, K.H.Larss. & Schigel. It was found that water, butanone, and toluene extracts promoted mycelial growth, xylene extracts neither inhibited nor promoted mycelial growth, while the other extracts slightly inhibited the growth of these fungi.

Nowadays, there are a lot of misinformation and myths related to both the deployment of antennas for 5G and the frequency bands used in such technology. Many of these myths arise from the lack of serious research documents released in common language to be understood by different knowledge areas. This work makes a small contribution in this regard and shows a bibliographic review of the most relevant characteristics related to the problem of deployment of transmitters (a.k.a. base stations), and also takes into account a spectrum sharing scheme. As a case study, we will analyze the CBRS regulation used in the United States for the deployment of 5G, it will provide an overview of engineering problems and also, the areas of research that still need to be explored.

Compared to other fibrous materials, plant fibers can act as a reinforcement in plastics due to their relatively high strength and rigidity, low cost, low density, biodegradability, and renewability. In this context, this study examines the effect of the particle size and content of white oak wood flour (Quercus laeta Liemb), obtained from its branches, on the properties of commercial polypropylene. In Mexico, wood from the branches of Quercus laeta Liemb is barely utilized despite its abundance and viability. The main objective of this study is to demonstrate that this waste material can be exploited to prepare useful materials, in this case composites with competitive properties. Tensile and flexural tests, as well as impact strength and melt flow index were evaluated. In addition, density and water absorption capacity were also tested. Results showed that the water absorption increased with the incorporation of wood particles. Mechanical properties were strongly influenced by particle content. A reduction in elongation and strength was observed, while Young’s modulus and flexural modulus increased with the incorporation of wood particles. Impact strength increased with particle size and particle content.

El presente artículo parte de un recuerdo autobiográfico para, a partir de allí, indagar en los mecanismos de construcción de identidades entre diferentes clubes de una liga de fútbol en la provincia de Misiones. En particular, se reconstruyen ciertos discursos y su incidencia en la configuración de polos identitarios que tienen efectos sobre el quehacer deportivo. A lo largo del análisis, se describen las operaciones simbólicas que constituyen al club Olimpia/San Antonio como aquel que, en la constelación de clubes en Oberá, representa y aglutina a los sectores populares. Teniendo en cuenta autores de las ciencias sociales en general como Elias, Hall y Reguillo pero también otros más específicos de los estudios sobre el fútbol tales como Arquetti y Alabarces, se analizan los modos en que las hinchadas de la liga local exteriorizan sus alteridades y pertenencias. A su vez, se indaga en diferentes niveles de construcciones hegemónicas y delimitación de alteridades tales como habilitado/inhabilitado, centro/periferia, rico/pobre, etc. ARK: http://id.caicyt.gov.ar/ark:/s18535925/s2nctp7g8