Cosmic reionization by primordial cosmic rays

After the so-called cosmic recombination, the expanding universe entered into a period of darkness since most of the matter was in a neutral state. About a billion years later, however, the intergalactic space was once again ionized. The process, known as the cosmic reionization, required the operation of mechanisms that are not well understood. Among other ionizing sources, Population III stars, mini-quasars, and X-ray emitting microquasars have been invoked. In this article we propose that primordial cosmic rays, accelerated at the termination points of the jets of the first microquasars, may have contributed to the reionization of the intergalactic space as well. For this we quantify the ionization power of cosmic rays (electrons and protons) in the primordial intergalactic medium using extensive particle cascade simulations. We establish that, depending on the fraction of electrons to protons accelerated in the microquasar jets, cosmic rays should have contributed to the reionization of the primordial intergalactic medium as much as X-rays from microquasar accretion disks. If the primordial magnetic field was of the order of $10^{-17}$ G, as some models suggest, cosmic rays had an important role in ionizing the neutral material far beyond the birth places of the first stars.Comment: 4 pages, 2 figures, accepted for publication as a letter to the editor in Astronomy and Astrophysic

Ingeniería de terapéuticos avanzados de microbioma usando E. coli Nissle 1917 para trastornos relacionados a ácidos biliares y neurodegenerativos

Los avances en la síntesis y secuenciación del ADN y una comprensión más profunda de los mecanismos biológicos y bioquímicos han permitido el desarrollo de microbios modificados y ha acelerado la velocidad a la que se construyen, prueban y optimizan. Esto ha llevado a la revolución de la biotecnología y su posterior aplicación a través de diferentes campos industriales. Si bien estos avances han tenido repercusiones significativas en el descubrimiento de nuevos fármacos y una mayor eficiencia en las capacidades de producción derivadas de fermentaciones microbianas, el sector médico no se ha beneficiado completamente del inmenso potencial que ofrece la biotecnología. Con el advenimiento de la investigación del microbioma, las enfermedades se están entendiendo desde una perspectiva diferente, teniendo en cuenta el papel que las bacterias que habitan en nuestro cuerpo tienen frente a estos eventos y cómo modulan positiva o negativamente las enfermedades. Desde este punto de vista, los microorganismos modificados tienen el potencial de ser mucho más que simples fábricas de células. Las cepas probióticas modificadas, por ejemplo, podrían orientarse para abordar enfermedades en el sitio, respondiendo a las necesidades del paciente y a las señales ambientales donde se han establecido. Esto podría resultar ser un enfoque novedoso para el tratamiento de enfermedades crónicas, que a menudo perjudican un estilo de vida normal, afectando profundamente la calidad de vida de los pacientes. En la misma línea de pensamiento, la cantidad de evidencia que respalda está inclinando la balanza hacia un tratamiento más personalizado, ya que se considera que una mayor comprensión de cómo se absorben, metabolizan, regulan y degradan los medicamentos depende en gran medida de las características de cada individuo. Se prevén terapias avanzadas de microbioma (AMT) para abordar los obstáculos que la medicina moderna ha cruzado. Estos microbios modificados podrían potencialmente colonizar el entorno de elección, dentro del cuerpo humano para brindar una acción terapéutica, mediante la producción de medicamentos específicos, la degradación de moléculas tóxicas o mediante la modulación de comunidades microbianas dañinas que representan un riesgo para el bienestar normal. Además, el desarrollo de tales cepas contribuye dramáticamente a la transición hacia una sociedad más sostenible, haciéndonos menos dependientes de los recursos naturales para las capacidades de producción, ya que estos microorganismos terapéuticos producirán los medicamentos necesarios utilizando los recursos que se encuentran normalmente en sus entornos dados. Sin embargo, esta tecnología se encuentra en sus primeras etapas y necesita más investigación para evaluar adecuadamente su potencial y comprender completamente sus capacidades. En la presente tesis, los ácidos biliares y los trastornos neurodegenerativos se toman como ejemplos para la ingeniería y el desarrollo de terapias microbianas avanzadas. Visualizándolos como posibles enfoques para abordar patologías en estas áreas, lo que permite un enfoque de tratamiento más eficaz. E. coli Nissle 1917, un probiótico bien documentado, se empleó como estructura bacteriana para dichas cepas previstas.Advances in DNA synthesis, sequencing and a deeper understanding of biological and biochemical mechanisms have enabled the development of engineered microbes, and has expedited the speed at which they are constructed, tested and optimized. This has led to the revolution of biotechnology and its further application through different industrial fields. Even though this advancements have had significant repercussions regarding the discovery of new drugs and an increased efficiency in production capabilities derived from microbial fermentations, the medical sector has not benefited fully from the immense potential biotechnology has to offer. With the advent of microbiome research, diseases are being understood from a different perspective, taking into account the role that bacteria inhabiting our bodies have towards these events and how they modulate positively or negatively diseases. In this view, engineered microorganisms have the prospective to be much more than simple cell factories. Engineered probiotic strains, for example, could be targeted to address diseases on site, responding to the patient’s needs and to the environmental cues where they have stablished. This could prove to be a novel approach for treating chronic diseases, which often impair a normal life style, affecting deeply the life quality of patients. On the same line of thought, supporting amount of evidence is tilting the balance towards a more personalized treatment, as more insights into how drugs are absorbed, metabolized, regulated and degraded, are seen to depend greatly on the characteristics of each individual. Advanced microbiome therapeutics (AMT)s are envisioned to address the hurdles that modern medicine has come a crossed. These engineered microbes could potentially colonize the environment of choice, within the human body to deliver therapeutic action, by the production of specific drugs, degradation of toxic molecules or by modulating harmful microbial communities that pose a risk for normal wellbeing. Additionally, the development of such strains contributes dramatically to the transition into a more sustainable society, making us less dependent on natural resources for production capabilities, as these therapeutic microorganisms will produce the needed drugs by utilizing normal occurring resources in their given environments. This technology, however, is in its early stages and needs further research to properly assess its potential and fully understand its capabilities. In the present thesis, bile acid and neurodegenerative disorders are taken as examples for the engineering and development of advanced microbiome therapeutics. Envisioning them as possible approaches to address pathologies in these areas, enabling a more efficacious treatment approach. E. coli Nissle 1917, a well-documented probiotic, was employed as the bacterial chassis for such intended strains.Dinamarca. Technical University of Denmark. Novo Nordisk Foundation. Copenhagen Bioscience PhD Programm

Educación y autogestión laboral en la experiencia peruana de propiedad social

A partir de la noción de ‘reproducción de las relaciones sociales de producción” y su importante función en la educación, se analizan sus mecanismos, la correspondencia y la contradicción, y la manera como a través de la genuina transformación, la reproducción puede transformar las relaciones sociales a través de la educación activa. Para ello se requieren cambios políticos y nuevas formas organizativas, tales como la autogestión de los trabajadores. El modelo de educación participatoria considera que, con prerrequisitos como la distribución y control democrático de recursos educativos, igualdad de acceso a beneficios educativos, y desarrollo de una conciencia participatoria, se pueden transformar 5 dimensiones para reproducir relaciones participatorias de producción: origen pluralista de recursos educativos, desescolarización, manejo democrática del proceso educativo, acción educativa permanente, y objetivos educativos participativos. El análisis de la experiencia peruana mencionada demuestra que no fue capaz de alterar las relaciones participatorias en la medida necesaria para alcanzar la transformación de las relaciones de producción tradicionales.Estados Unidos. Fundación Ford. Beca de Posgrado, Lima, 197

Establecimiento de claves seguro mediante códigos sonoros en dispositivos móviles

El objetivo de este trabajo ha sido investigar el uso de canales sonoros para el intercambio de claves en teléfonos inteligentes. Para ello, se ha realizado un diseño y un análisis del problema a resolver, teniendo en cuenta factores como la necesidad de sincronización, los parámetros de escucha, la longitud de la clave que podemos obtener, los ataques a los que sería vulnerable el protocolo, la necesidad de cierta persistencia a nivel local, el uso de la nube, etc. Se ha realizado un análisis de tecnologías relacionadas, eligiendo aquellas que mejor se adaptan a los requisitos del problema y se ha implementado un prototipo capaz de realizar un intercambio de claves y autenticar mutuamente a un par de dispositivos, creando así un canal seguro a través del cual puedan comunicarse en el futuro, sin necesidad de que una tercera parte confiable que certifique la identidad de las partes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Missing energy estimate in the light of the muon discrepancy

The determination of the primary energy of extensive air showers using the fluorescence technique requires an estimation of the energy carried away by the particles that do not deposit all their energy in the atmosphere. This estimation is typically made using Monte Carlo simulations and thus depends on the model predictions for neutrino and muon production. In this contribution we describe a new method that could be used to obtain the missing energy directly from events measured simultaneously with the fluo- rescence and the surface detectors of the Pierre Auger Observatory, based on a toy model of the shower cascade. The method is applied to a synthetic sample of events to show its robustness and we discuss how the results could be used to make an estimation of the number of high energy muons in the cascade.Fil: Tueros, Matias Jorge. Universidad de Santiago de Compostela; España. Observatorio Pierre Auger; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: The Pierre Auger Collaboration. No especifíca;International Symposium on Future Directions in Ultra High Energy Cosmic Ray PhysicsGinebraSuizaConseil Européen pour la Recherche Nucléair

Radio wavefront of very inclined extensive air-showers observed with extended and sparse radio arrays

In this article we perform a simulation-based study of the shape of the electromagnetic wavefront of air showers induced by cosmic rays. We show that for showers with zenith angles larger than 60{\deg}, a point-source like description of the wave-front is sufficient and that the reconstructed position of this point-source is a potential proxy for the determination of the nature of the cosmic rays initiating the showers, with performances similar to those obtained using the depth of shower maximum.Comment: 16 pages, 8 figures. arXiv admin note: text overlap with arXiv:2107.0320

Sensitivity and specificity of a brief scale to evaluate psychological violence at work in Peruvian health professionals

Objective: Most studies in Latin America that evaluate psychological violence at work (PVW) focus on measuring occurrences of PVW. However, the discriminative validity and randomness of instruments used for evaluating incidents of PVW that are generated by agents internal to the workplace in the Peruvian health sector have not yet been studied. The objective of this study was to determine the sensitivity and specificity of the Scale of Psychological Violence in Health Professionals (SVP-Health) in the Peruvian population. For this purpose, a cross-sectional study based on the two-stage administration of guided surveys and ROC (receiver operating characteristic) curve analysis was performed. Results: The study included 188 professionals from ten care centres in Peru. The professionals were divided into two groups of 94 subjects: those who had experienced PVW and those who had not. The average age of the participants was 36.8±10.5 years; their work experience ranged between one and 35 years; and 59% of the sample were women. According to an analysis based on the ROC curve, (a) there was a significant area under the curve (AUC=0.899) with adequate randomness; and (b) the SPV-Health adequately distinguished subjects with PVW from those without PVW (89% versus 94%)

Addressing Digital Technologies Needed for Students in K-12 Schools

This research aimed to learn more about how K-12 schools have addressed the needs of all students in their school districts equally as it relates to access for appropriate technology for distance learning. The intended research was conducted through Qualtrics, an online survey software, which was dispersed through social media sites to reach broad and diverse pool of participants within this study’s target audience, to include parents, teachers, and administrations in a K-12 school system. Participants who clicked on the link to the survey were given an informed consent notice, including an explanation of how distance learning and equitable access to technology is defined for the context of the study, and date when the survey will be closed down. The data from the study was collected and interpreted using Qualtrics data analysis methods, which were compared with prior literature to provide insight on factors that influence equitable access to digital technology