A New Natural Antimycotic Agent is Effective Against Oropharyngeal Candidiasis: The VIPROCAN Study.

Background: The incidence of community and nosocomial candidiasis has dramatically increased in the last two decades. There are multiple treatments for this infection, but the toxicity of some and the induction of resistant strains require the development of new compounds. Objectives: With the aim of reducing the Candida population in the oropharyngeal cavity, we have formulated a toothpaste with VG-01 agent, composed of a mixture of carnosic acid (CA) and propolis (PP). Methods: We investigated the ability of VG-01 toothpaste to minimize and stabilize fungal presence in 21 patients diagnosed with clinical oropharyngeal candidiasis. Results: Our data indicate that VG-01 toothpaste showed an effect not only against the most frequent species of Candida, C. albicans, but also in the other species analyzed. 82% of patients stated that they would continue using it outside the study. Conclusion: Our data demonstrate that VG-01, composed of CA and PP is a potential antimycotic agent effective against the most common species that cause oropharyngeal candidiasis present in clinical practicepost-print988 K

Pre-vaccine rotavirus surveillance in Buenos Aires, Argentina: Characterization of an emergent G1P[8] strain associated to fatal cases in 2014

Group A rotaviruses (RVA) are the most frequent etiological agents causing severe diarrhea in infants and surveillance of genotype, and genetic characteristics of circulating strains are necessary in order to evaluate vaccine programs. The objectives of this work were to describe G and P genotype from 2012 through 2014 in Buenos Aires, Argentina completing an overview of 19 years of genotype surveillance in our region and to characterize an emerging G1P[8] strain associated with severe cases and five fatalities in 2014. We performed genotyping by RT-PCR. The sequencing of several genes, phylogenetic analyses, and comparative epidemiological data were used to know the origin and phylogenetic relationships of the emerging G1P[8] strain. Along with this report, 19 years of continuous RVA genotype surveillance in Argentina in the pre-vaccine era was covered. During the last year of this surveillance, 2014, a significantly increased incidence of RVA associated gastroenteritis was related to the reemergence of G1P[8] strains, being these ones detected in low frequency in the last nine years. Interestingly, the patients affected were significantly older when compared with those from the last six seasons. Additionally, phylogenetic analysis of several genes infer that these G1P[8] strains were closely related to Asian strains circulating during 2012 and 2013. In addition to this, the suggested extra continental origin for the 2014 G1P[8] strains and the very low circulation of G1 type during nine years probably explain the increased incidence and severity in the gastroenteritis cases and the particular epidemiologic characteristics. In conclusion, this work gives us a whole panorama of the pre-vaccine era of the RVA molecular epidemiology in the most populated region of Argentina. In this way, this work inspires us to continue with this type of studies in the post-vaccination era.Fil: Mandile, Marcelo Gastón. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Argüelles, Marcelo Horacio. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Temprana, Carlos Facundo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Peri Ibañez, Estefania Soledad. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Silvestre, Dalila. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Musto, Alejandra Beatriz. Gobierno de la Provincia de Buenos Aires. Hospital Provincial Evita Pueblo.; ArgentinaFil: Rodríguez Pérez, Alberto. Hospital General de Agudos Dr. Alberto A. Eurnekian; ArgentinaFil: Mistchenko, Alicia Susana. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Departamento de Medicina; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Almallo de Glikmann, Graciela. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; ArgentinaFil: Castello, Alejandro Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; Argentina. Universidad Nacional Arturo Jauretche; Argentin

Economía Colaborativa Una Respuesta para la Articulación de Jóvenes Creadores con el Sector Audiovisual Colombiano

El presente artículo analiza el modelo de la economía colaborativa en el contexto de la brecha entre creadores audiovisuales en etapa de profesionalización y la industria audiovisual del país, a partir de la comprensión conceptual del modelo y sus bases económicas fundamentales. Se procede de la siguiente manera: (i) se analizan las dinámicas de consumo, su impacto y la academia en el marco del sector audiovisual (ii) Se asocian las características de la economía colaborativa con los factores analizados de la industria y se plantean acciones claves como posibles soluciones a la problemática evidenciada. (iii) Finalmente se presentan proyectos de referencia para la adopción de un modelo con características de la economía colaborativa que dé oportunidades más justas e inclusivas con los jóvenes creadores

Two new species of Hechtia (Bromeliaceae; Hechtioideae) from Jalisco, Mexico

Backgrounds and aims – The genus Hechtia (sensu lato) is distributed from the southern United States to northern Central America and includes 95 species. Recent botanical explorations, carried out in the Colima and Jalisco states in search of H. reticulata, led to the discovery of two new species. The aims of this work were to complete the morphological description of H. reticulata and describe these two new species. Material and methods – This study was based on fieldwork and on the revision of literature, protologues, type material, and herbarium specimens. The specimens collected were prepared for storage in the herbarium, analysed, measured, and descriptions were made; measurements were taken from dried specimens. Due to their morphological similarities and the closeness of their populations, the proposed species are compared with H. reticulata. Key results – We propose two new species of Hechtia for Mexico (H. costalegrensis and H. pacifica); an epitype and a complete description of H. reticulata are also provided. The diagnostic characters and morphological affinities of the new species are discussed, including complete morphological descriptions and images; a comparative table is presented, showing the morphological differences between the new species and H. reticulata. A distribution map of the taxa described here and of H. reticulata is included, as well as an identification key and a list of examined specimens of all Hechtia species known to date from Colima and Jalisco

Selective Dynamical Imaging of Interferometric Data

Recent developments in very long baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of the EHT's (u, v)-coverage presents a challenge when attempting to resolve highly time-variable sources. We demonstrate that the changing (u, v)-coverage of the EHT can contain regions of time over the course of a single observation that facilitate dynamical imaging. These optimal time regions typically have projected baseline distributions that are approximately angularly isotropic and radially homogeneous. We derive a metric of coverage quality based on baseline isotropy and density that is capable of ranking array configurations by their ability to produce accurate dynamical reconstructions. We compare this metric to existing metrics in the literature and investigate their utility by performing dynamical reconstructions on synthetic data from simulated EHT observations of sources with simple orbital variability. We then use these results to make recommendations for imaging the 2017 EHT Sgr A* data set

First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass

In this paper we quantify the temporal variability and image morphology of the horizon-scale emission from Sgr A*, as observed by the EHT in 2017 April at a wavelength of 1.3 mm. We find that the Sgr A* data exhibit variability that exceeds what can be explained by the uncertainties in the data or by the effects of interstellar scattering. The magnitude of this variability can be a substantial fraction of the correlated flux density, reaching ∼100% on some baselines. Through an exploration of simple geometric source models, we demonstrate that ring-like morphologies provide better fits to the Sgr A* data than do other morphologies with comparable complexity. We develop two strategies for fitting static geometric ring models to the time-variable Sgr A* data; one strategy fits models to short segments of data over which the source is static and averages these independent fits, while the other fits models to the full data set using a parametric model for the structural variability power spectrum around the average source structure. Both geometric modeling and image-domain feature extraction techniques determine the ring diameter to be 51.8 ± 2.3 μas (68% credible intervals), with the ring thickness constrained to have an FWHM between ∼30% and 50% of the ring diameter. To bring the diameter measurements to a common physical scale, we calibrate them using synthetic data generated from GRMHD simulations. This calibration constrains the angular size of the gravitational radius to be 4.8−0.7+1.4 μas, which we combine with an independent distance measurement from maser parallaxes to determine the mass of Sgr A* to be 4.0−0.6+1.1×106 M ⊙

Characterizing and Mitigating Intraday Variability: Reconstructing Source Structure in Accreting Black Holes with mm-VLBI

The extraordinary physical resolution afforded by the Event Horizon Telescope has opened a window onto the astrophysical phenomena unfolding on horizon scales in two known black holes, M87* and Sgr A*. However, with this leap in resolution has come a new set of practical complications. Sgr A* exhibits intraday variability that violates the assumptions underlying Earth aperture synthesis, limiting traditional image reconstruction methods to short timescales and data sets with very sparse (u, v) coverage. We present a new set of tools to detect and mitigate this variability. We develop a data-driven, model-agnostic procedure to detect and characterize the spatial structure of intraday variability. This method is calibrated against a large set of mock data sets, producing an empirical estimator of the spatial power spectrum of the brightness fluctuations. We present a novel Bayesian noise modeling algorithm that simultaneously reconstructs an average image and statistical measure of the fluctuations about it using a parameterized form for the excess variance in the complex visibilities not otherwise explained by the statistical errors. These methods are validated using a variety of simulated data, including general relativistic magnetohydrodynamic simulations appropriate for Sgr A* and M87*. We find that the reconstructed source structure and variability are robust to changes in the underlying image model. We apply these methods to the 2017 EHT observations of M87*, finding evidence for variability across the EHT observing campaign. The variability mitigation strategies presented are widely applicable to very long baseline interferometry observations of variable sources generally, for which they provide a data-informed averaging procedure and natural characterization of inter-epoch image consistency

First Sagittarius A* Event Horizon Telescope Results. VI. Testing the Black Hole Metric

Astrophysical black holes are expected to be described by the Kerr metric. This is the only stationary, vacuum, axisymmetric metric, without electromagnetic charge, that satisfies Einstein’s equations and does not have pathologies outside of the event horizon. We present new constraints on potential deviations from the Kerr prediction based on 2017 EHT observations of Sagittarius A* (Sgr A*). We calibrate the relationship between the geometrically defined black hole shadow and the observed size of the ring-like images using a library that includes both Kerr and non-Kerr simulations. We use the exquisite prior constraints on the mass-to-distance ratio for Sgr A* to show that the observed image size is within ∼10% of the Kerr predictions. We use these bounds to constrain metrics that are parametrically different from Kerr, as well as the charges of several known spacetimes. To consider alternatives to the presence of an event horizon, we explore the possibility that Sgr A* is a compact object with a surface that either absorbs and thermally reemits incident radiation or partially reflects it. Using the observed image size and the broadband spectrum of Sgr A*, we conclude that a thermal surface can be ruled out and a fully reflective one is unlikely. We compare our results to the broader landscape of gravitational tests. Together with the bounds found for stellar-mass black holes and the M87 black hole, our observations provide further support that the external spacetimes of all black holes are described by the Kerr metric, independent of their mass

The Event Horizon Telescope Image of the Quasar NRAO 530

We report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5−7, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. At z = 0.902, this is the most distant object imaged by the EHT so far. We reconstruct the first images of the source at 230 GHz, at an unprecedented angular resolution of ∼20 μas, both in total intensity and in linear polarization (LP). We do not detect source variability, allowing us to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which we associate with the core. The feature is linearly polarized, with a fractional polarization of ∼5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle ∼ −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. Future EHT observations will probe the variability of the jet structure on microarcsecond scales, while simultaneous multiwavelength monitoring will provide insight into the high-energy emission origin