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Time-varying media break temporal symmetries while preserving spatial symmetries intact. Thus, it represents an excellent conceptual framework to investigate the fundamental implications of Noether’s theorem for the electromagnetic field. At the same time, addressing momentum conservation in time-varying media sheds light on the Abraham-Minkowski debate, where two opposing forms of the electromagnetic field momentum are defended. Here, we present a tutorial review on the conservation of momentum in time-varying media. We demonstrate that the Minkowski momentum is a conserved quantity with three independent approaches of increasing complexity: (i) via the application of the boundary conditions for Maxwell equations at a temporal boundary, (ii) testing for constants of motion and deriving conservation laws, and (iii) applying temporal and spatial translations within the framework of the Lagrangian theory of the electromagnetic field. Each approach provides a different and complementary insight into the problem.

El impacto de las secuelas post-infecciosas del COVID-19 son un problema real para el control y tratamiento de las adicciones, debido a que las afectaciones previas por consumo de sustancias psicoactivas empeoran significativamente, y algunos de estos déficits serán permanentes en el individuo. Esta investigación tuvo por objetivo contrastar el efecto de las vacunas con el aparecimiento de secuelas post-infecciosas del COVID-19 comparando 240 personas, que fueron divididas en tres grupos. Se evaluaron los procesos cognitivos y de regulación emocional, a través de la aplicación del MME y de la EDAE, respectivamente. Los resultados arrojaron datos no significativos en las alteraciones de los participantes con adicción, antecedentes de COVID-19 y vacunación previa a la infección, lo que nos lleva a concluir que las vacunas contra la COVID-19 presentan una importante eficiencia en la protección de secuelas post-infecciosas del COVID-19, al menos, en personas con diagnóstico de adicción.

Temporal metamaterials empower novel forms of wave manipulation with direct applications to quantum state transformations. In this work, we investigate vacuum amplification effects in anisotropic temporal boundaries. Our results theoretically demonstrate that the anisotropy of the temporal boundary provides control over the angular distribution of the generated photons. We analyze several single and multi-layered configurations of anisotropic temporal boundaries, each with a distinct vacuum amplification effect. Examples include the inhibition of photon production along specific directions, resonant and directive vacuum amplification, the generation of angular and frequency photon combs and fast angular variations between inhibition and resonant photon production.

Para una gran cantidad de procesos industriales, la identificación del patrón de flujo presente es importante para un diseño adecuado de equipos de intercambio de calor, sistemas de bombeo, celdas de combustible, entre otros. Este trabajo tiene como principal objetivo diseñar e implementar clasificador mediante una interfaz gráfica de usuario para la identificación de patrones de flujo en imágenes normalizadas de flujos reales de dos fases. La característica principal de este método es que permite realizar la identificación de patrones de manera no invasiva. Debido a la complejidad de las interacciones entre las fases del flujo líquido gas existe el interés de generar un algoritmo capaz de encontrar el patrón de flujo presente que dicte el comportamiento termo hidráulico del fluido. Identificar este comportamiento es una tarea ardua que requiere de expertos en diversas áreas, este trabajo basa su conocimiento a partir del entrenamiento previo de una red neuronal convolucional. Se muestra el desarrollo de la interfaz gráfica para los fluidos bifásicos y, que proporcionaron resultados de identificación de imágenes con una eficiencia arriba del 93% para diferentes patrones de flujo: bala, anular, semi anular, anular disperso y anular bajo.

A case is reported with a prolonged recovery of parathyroid function after a total thyroidectomy.

We investigate the presence of hub-filament systems in a large sample of 146 active proto-clusters, using H$^{13}$CO$^{+}$ J=1-0 molecular line data obtained from the ATOMS survey. We find that filaments are ubiquitous in proto-clusters, and hub-filament systems are very common from dense core scales ($\sim$0.1 pc) to clump/cloud scales ($\sim$1-10 pc). The proportion of proto-clusters containing hub-filament systems decreases with increasing dust temperature ($T_d$) and luminosity-to-mass ratios ($L/M$) of clumps, indicating that stellar feedback from H{\sc ii} regions gradually destroys the hub-filament systems as proto-clusters evolve. Clear velocity gradients are seen along the longest filaments with a mean velocity gradient of 8.71 km s$^{-1}$pc$^{-1}$ and a median velocity gradient of 5.54 km s$^{-1}$pc$^{-1}$. We find that velocity gradients are small for filament lengths larger than $\sim$1~pc, probably hinting at the existence of inertial inflows, although we cannot determine whether the latter are driven by large-scale turbulence or large-scale gravitational contraction. In contrast, velocity gradients below $\sim$1~pc dramatically increase as filament lengths decrease, indicating that the gravity of the hubs or cores starts to dominate gas infall at small scales. We suggest that self-similar hub-filament systems and filamentary accretion at all scales may play a key role in high-mass star formation., 16 pages

Las secuelas provocadas por la enfermedad Covid-19 podrían surgir como un importante problema para el control y tratamiento de las adicciones, considerando que su cuadro clínico incide, sobre todo, en padecimientos neurológicos que por si generan déficits neurocognitivos. La investigación pretendió contrastar el incremento de los déficits neuropsicológicos en personas con trastornos relacionados con sustancias y diagnóstico de Covid-19. Este es un estudio comparativo con la participación de 96 participantes evaluados en los ámbitos neuropsicológicos (NEUROPSI) y regulación emocional (DASS- 21). La comparación de los resultados de la evaluación, de las dimensiones neurocognitivas podrían significar diferencias estadísticamente significativas y un incremento de la afectación, en la orientación, atención, memoria, lenguaje, lectura, escritura y funciones ejecutivas. Se concluye que en el trastorno relacionado con sustancias y diagnóstico de Covid-19, empeoran los síntomas cognitivos iniciales del consumo, bien como las alteraciones de la regulación emocional, considerando la ansiedad, estrés y depresión

We present a numerical study of the gravity-driven filamentary flow arising in the presence of elongated perturbations embedded in a globally gravitationally unstable medium. We perform idealized simulations of the gravitational collapse of a moderate filamentary perturbation with a central enhancement (a core) embedded in either a uniform or a stratified background. Both simulations maintain the filamentary structure during the collapse, developing a hierarchical accretion flow from the cloud to the filament, and from the filament to the core. Only the stratified simulation produces a flat central density profile of filaments, best matching the observed Plummer-like profiles, supporting suggestions that molecular clouds may be preferentially flattened. The flow changes direction smoothly from the cloud to the filament, with no density divergence nor a shock developing at the filament’s axis during the prestellar evolution. The drainage of material by the filament-to-core accretion slows down the growth of the filament, causing the ratio of the core’s central density to the filament’s axial density to increase in time, and to diverge at the time when a singularity (protostar) forms in the core. We argue that the system should evolve towards a stationary state in which the filament-to-core accretion balances the cloud-to-filament one, and search for it in the simulations, but find no unambiguous evidence. However, we find that, after a period of accelerated increase, the filament’s linear mass density reaches a linear growth rate. The stationary state may be approached during the protostellar stage.

La Inteligencia Artificial (IA) es una tecnología de alto riesgo que está interconectada globalmente y que actualmente carece de una regulación en los tratados internacionales, salvo en la Unión Europea. Los intentos de una gobernanza internacional para controlar la IA se restringen a los derechos humanos o los foros comerciales. La carrera entre Estados Unidos y China por desarrollar la IA aleja todavía más la posibilidad de una legislación común. Este trabajo de investigación propone edificar una nueva arquitectura legal sobre esta tecnología que dirige los coches autónomos, el suministro eléctrico, la concesión de un empleo o un seguro, así como los drones y nuevos tipos de armas autónomas. En la primera actuación global sobre IA, la UNESCO han aprobado su recomendación sobre ética en la IA para 193 Estados miembros y este se puede considerar el primer intento de estandarizar la regulación de la IA en el ámbito transnacional.

Refortalecimiento is a strategy for transformation that started with a debate with the empowerment theory. We have been clarifying the notion of refortalecimiento from experiences at communities and academic’s scenarios. As a result, we need to re-imagine some of our concepts to address the consequences of inequalities. In this article, we will present some reflections about three concepts: intervention, prevention model, and empowerment theory based in an Intervention-Investigation (I-I) realized in a community with a group of mothers of children with disabilities (diverse abilities) in an impoverish community in Puerto Rico. We confirmed the need to reevaluate the impact of different concepts/perspectives operating within the project that undermine the implementation process. We learned that the beauty of this process resides on the reciprocity and the fortalezas (strengths) that takes place within all the people involved. But we also find out neoliberal values as: individualism, competition, and everyone for themselves presented great obstacles to overcome discrimination and disparities. How to cite this article: Vázquez-Rivera, C. & Rojas-Livia, J. (2021). Refortalecimiento: Beyond prevention,empowerment and intervention in an improverish community in Puerto Rico. Revista Colombiana de Psicología, 31 (1), 109-124. https://doi.org/10.15446/rcp.v31n1.88726

We present ALMA Band-3/7 observations towards "the Heart" of a massive hub-filament system (HFS) SDC335, to investigate its fragmentation and accretion. At a resolution of $\sim0.03$ pc, 3 mm continuum emission resolves two massive dense cores MM1 and MM2, with $383(^{+234}_{-120})$ $M_\odot$ (10-24% mass of "the Heart") and $74(^{+47}_{-24})$ $M_\odot$, respectively. With a resolution down to 0.01 pc, 0.87 mm continuum emission shows MM1 further fragments into six condensations and multi-transition lines of H$_2$CS provide temperature estimation. The relation between separation and mass of condensations at a scale of 0.01 pc favors turbulent Jeans fragmentation where the turbulence seems to be scale-free rather than scale-dependent. We use the H$^{13}$CO$^+$ (1-0) emission line to resolve the complex gas motion inside "the Heart" in position-position-velocity space. We identify four major gas streams connected to large-scale filaments, inheriting the anti-clockwise spiral pattern. Along these streams, gas feeds the central massive core MM1. Assuming an inclination angle of $45(\pm15)^{\circ}$ and a H$^{13}$CO$^+$ abundance of $5(\pm3)\times10^{-11}$, the total mass infall rate is estimated to be $2.40(\pm0.78)\times10^{-3}$ $M_\odot$ yr$^{-1}$, numerically consistent with the accretion rates derived from the clump-scale spherical infall model and the core-scale outflows. The consistency suggests a continuous, near steady-state, and efficient accretion from global collapse, therefore ensuring core feeding. Our comprehensive study of SDC335 showcases the detailed gas kinematics in a prototypical massive infalling clump and calls for further systematic and statistical analyses in a large sample., 29 pages, 7 figures, Accepted for publication in MNRAS

Whether ionization feedback triggers the formation of massive stars is highly debated. Using ALMA 3 mm observations with a spatial resolution of $\sim 0.05$ pc and a mass sensitivity of 1.1 $\rm M_\odot$ beam$^{-1}$ at 20 K, we investigate the star formation and gas flow structures within the ionizing feedback-driven structure, a clump-scale massive ($\gtrsim 1500$ $\rm M_\odot$) bright-rimmed cloud (BRC) associated with IRAS 18290-0924. This BRC is bound only if external compression from ionized gas is considered. A small-scale ($\lesssim1$ pc) age sequence along the direction of ionizing radiation is revealed for the embedded cores and protostars, which suggests triggered star formation via radiation-driven implosion (RDI). Furthermore, filamentary gas structures converge towards the cores located in the BRC's center, indicating that these filaments are fueling mass towards cores. The local core-scale mass infall rate derived from H$^{13}$CO$^+$ $J=1-0$ blue profile is of the same order of magnitude as the filamentary mass inflow rate, approximately 1 $\rm M_\odot$ kyr$^{-1}$. A photodissociation region (PDR) covering the irradiated clump surface is detected in several molecules, such as CCH, HCO$^+$, and CS whereas the spatial distribution stratification of these molecules is indistinct. CCH spectra of the PDR possibly indicate a photoevaporation flow leaving the clump surface with a projected velocity of $\sim2$ km s$^{-1}$. Our new observations show that RDI accompanied by a clump-fed process is operating in this massive BRC. Whether this combined process works in other massive BRCs is worth exploring with dedicated surveys., 34 pages with 20 figures, Accepted by MNRAS on 2022 December 28

We investigate the effect of numerical magnetic diffusion in magnetohydrodynamic simulations of magnetically supported molecular clouds. To this end, we have performed numerical studies on adaptive mesh isothermal simulations of marginally sub-critical molecular clouds. We find that simulations with low and intermediate resolutions collapse, contrary to what is theoretically expected. However, the simulation with the highest numerical resolution oscillates around an equilibrium state without collapsing. In order to quantify the numerical diffusion of the magnetic field, we ran a second suit of current-sheet simulations in which the numerical magnetic diffusion coefficient can be directly measured, and computed the corresponding diffusion times at various numerical resolutions. On this basis, we propose a criterion for the resolution of magnetic fields in MHD simulations based on requiring that the diffusion time to be larger than the characteristic timescale of the physical process responsible for the dynamic evolution of the structure., Comment: 7 pages, 5 figures, 2 tables. Accepted to MNRAS

Bacillus Calmette-Guérin (BCG), the nonpathogenic Mycobacterium bovis strain used as tuberculosis vaccine, has been successfully used as treatment for non-muscle invasive bladder cancer for decades, and suggested to potentiate cellular and humoral immune responses. However, the exact mechanism of action is not fully understood. We previously described that BCG mainly activated anti-tumor cytotoxic NK cells with upregulation of CD56 and a CD16+ phenotype. Now, we show that stimulation of human peripheral blood mononuclear cells with iBCG, a preparation based on BCG-Moreau, expands oligoclonal γδ T-cells, with a cytotoxic phenotype, together with anti-tumor CD56high CD16+ NK cells. We have used scRNA-seq, flow cytometry, and functional assays to characterize these BCG-activated γδ T-cells in detail. They had a high IFNγ secretion signature with expression of CD27+ and formed conjugates with bladder cancer cells. BCG-activated γδ T-cells proliferated strongly in response to minimal doses of cytokines and had anti-tumor functions, although not fully based on degranulation. BCG was sufficient to stimulate proliferation of γδ T-cells when cultured with other PBMC; however, BCG alone did not stimulate expansion of purified γδ T-cells. The characterization of these non-donor restricted lymphocyte populations, which can be expanded in vitro, could provide a new approach to prepare cell-based immunotherapy tools.

Maternal overnutrition during pregnancy leads to metabolic and immune alterations, including obesity, hyperphagia, and central and peripheral inflammation in offspring. Exposure to high-energy diets during pregnancy primes ghrelin sensitivity to overfeeding in the offspring at early stages of life. Overfeeding has also been partially related to the early stages of chronic stress. We hypothesized that maternal programming sensitizes ghrelin-induced overfeeding following a chronic stress schedule in the offspring. We used a nutritional programming model exposing female Wistar rats to a cafeteria (CAF) or control diet from prepregnancy to weaning. Male offspring were injected with ghrelin and then subjected to a chronic immobilization stress (CIS) schedule, after which food intake was determined. Hypothalamic and plasma accumulation of cytokines and cortisol were evaluated using BioPlex analysis and enzyme-linked immunosorbent assay, respectively. We found that rats exposed to the CAF diet exhibited overfeeding after fasting and peripheral ghrelin administration, which was exacerbated in rats exposed to chronic stress. Offspring exposed to the CAF diet accumulated pro-inflammatory interleukin-6 (IL-6), interferon-γ, and monocyte chemoattractant protein-1 cytokines in plasma, and IL-6 cytokine in the hypothalamus. Ghrelin-sensitive overfeeding in rats exposed to CAF diet + CIS display increased cortisol levels and decreased IL-6 accumulation in plasma. Together, our results suggest that maternal nutritional programming primes susceptibility to ghrelin response for overfeeding after a CIS schedule that mirrors plasma cortisol accumulation in male offspring.

Introducción: La hiperplasia adrenal congénita (HAC) incluye un grupo de trastornos autosómicos recesivos que afectan la biosíntesis de cortisol, donde los varones afectados no tienen ambigüedad sexual. Objetivo: Describir la secuencia diagnóstica del diagnóstico prenatal de hiperplasia adrenal congénita en feto masculino con genitales ambiguos. Presentación del caso: Gestante de 26 años, primípara, que a finales del segundo trimestre se describe durante estudio ecográfico restricción del crecimiento fetal, alteraciones a nivel del sistema nervioso central y genitales con bolsas escrotales vacías y pedúnculo genital paralelo a la columna vertebral por lo que se sospecha se trate de un feto femenino con genitales ambiguos. Se indica estudio molecular de hiperplasia adrenal congénita mediante realización de amniocentesis y diagnóstico molecular de sexo. Discusión: El estudio molecular permitió el diagnóstico prenatal de la enfermedad en un feto masculino, constituyendo esta última condición un hallazgo inesperado dada la apariencia de genitales ambiguos en la ecografía que sugerían se tratara de un feto femenino. Conclusiones: La sospecha diagnóstica de hiperplasia adrenal congénita ante la presencia de genitales indiferenciados es importante en aras de su diagnóstico temprano para un adecuado asesoramiento genético y manejo de la enfermedad.

We present the case of a 79 y.o. male diagnosed with tuberculosis and mediastinal lymphadenopathy fistulizing in the esophageal lumen. Despite a number of treatments, including over-the scope (OVESCO) clip, the patient had intolerance for oral intake and repeated infections.

RESUMO A evasão no Ensino Superior constitui preocupação internacional com impacto nas Instituições de Ensino Superior, em geral, e nos percursos de carreira individuais, em específico. Para prevenir esse fenômeno e apoiar tanto instituições como estudantes na sua tomada de decisão, urge identificar fatores de evasão no ensino superior. Apresenta-se revisão de artigos publicados em revistas científicas internacionais entre janeiro 2014 e dezembro 2018, com base no Modelo Longitudinal de Evasão Institucional. A pesquisa foi realizada em quatro bases de dados, com combinações das palavras-chave dropout, departure, academic adjustment, college adjustment, academic integration, social integration e higher education. Foram lidos integralmente 24 artigos que satisfaziam critérios de inclusão. Procedeu-se à descrição dos artigos e o conteúdo foi sistematizado em meta-síntese. Identificaram-se fatores relativos a atributos prévios à entrada no ensino superior; objetivos e compromissos prévios e posteriores a essa entrada; experiências institucionais; integração acadêmica e social. Identificaram-se ainda medidas de sinalização de evasão. Discutem-se implicações para a investigação, para serviços e políticas das Instituições de Ensino Superior. RESUMEN La evasión en lo Enseñanza Universitaria constituye preocupación internacional con impacto en las Instituciones de Enseñanza Universitaria, en general, y en los recorridos de carrera individuales, en específico. Para prevenir ese fenómeno y apoyar tanto instituciones, como estudiantes en su toma de decisión, es urgente identificar factores de evasión en la enseñanza universitaria. Se presenta revisión de artículos publicados en revistas científicas internacionales entre enero 2014 y diciembre 2018, con base en el Modelo Longitudinal de Evasión Institucional. La investigación se realizó en cuatro bases de datos, con combinaciones de las palabras clave dropout, departure, academic adjustment, college adjustment, academic integration, social integration y higher education. Se leyeron integralmente 24 artículos que satisfacían criterios de inclusión. Se procedió a la descripción de los artículos y se sistematizó los contenidos en meta-síntesis. Se identificaron factores relativos a atributos previos al ingreso en la enseñanza universitaria; objetivos y compromisos previos y posteriores a esa entrada; experiencias institucionales; integración académica y social. Se identificaron, aún medidas de señalización de evasión. Se discuten implicaciones para la investigación, para servicios y políticas de las Instituciones de Enseñanza Universitaria. ABSTRACT Dropping out of Higher Education is an international concern with an impact on Higher Education Institutions, in general, and on individual career paths, in particular. In order to prevent this phenomenon and support both institutions and students in their decision-making, it is urgent to identify evasion factors in higher education. A review made in published articles in international scientific journals between January 2014 and December 2018 is presented, based on the Longitudinal Institutional Evasion Model. The search was carried out in four databases, with combinations of the keywords dropout, departure, academic adjustment, college adjustment, academic integration, social integration, and higher education. Twenty-four articles that met the inclusion criteria were fully read. The articles were described and the content was systematized in meta-synthesis. Factors related to attributes prior to entering higher education were identified; objectives and commitments prior and subsequent to this entry; institutional experiences; academic and social integration. Evasion signaling measures were also identified. Implications for research, services and policies of Higher Education Institutions are discussed.

The performance of an endoscopic procedure involves introducing an endoscope through the mouth or the anus, which may potentially lead to lethal infection. The risk increases when complex and difficult-to-clean scopes are used, as in the case of duodenoscopes. Side-viewing duodenoscopes are complex in design, with the camera and working channel exit located on one side of the endoscope's distal end, and with an elevator nail also located at this point for catheter redirection. This complex design may facilitate the presence of blind areas not easy to access for cleaning, resulting in suboptimal disinfection of the duodenoscope and therefore a higher risk of bacterial infection. This is of particular importance in particularly vulnerable patients like those who are immunosuppressed (e.g., transplanted patients) or have a malignant disease and are receiving chemotherapy. Moreover, in the era of ¨superbugs¨, like carbapenem-resistant Enterobacteriaceae, infection outbreaks related to endoscopic retrograde cholangiopancreatography (ERCP) have been reported with a significant mortality rate.