Entre la ciencia y la cultura: La conformación de discursos médicos sobre la homosexualidad en el contexto del surgimiento del VIH/SIDA en Costa Rica

En este artículo se analiza la manera en que el discurso médico conceptualizó y representó a la homosexualidad cuando surge el VIH/SIDA en Costa Rica. Se hace una reflexión teórica en torno al tema de la sexualidad como objeto de estudio, y se problematizan las diferentes maneras con las cuales se nombra a los sujetos históricos, seguidamente se analizan los discursos periodísticos. La dinámica saber/poder secual se articula y se institucionaliza en el discurso médico a través de los medios de comunicación; ambas instituciones, junto a la Iglesia, jjugaron un papel fundamental en la progagaciónk de imágenes abyectas sobre la homosexualidad masculina, principalmente

One-pot synthesis of ZnO–Ag and ZnO–Co nanohybrid materials for photocatalytic applications

ZnO–Ag and ZnO–Co nanohybrid materials with different Ag and Co contents were successfully prepared through a simple one-pot method at room temperature in the absence of surfactants. This synthesis route is effective and environmentally friendly and can produce spherical nanoparticles with sizes between 7 and 20 nm. The nanohybrid materials were characterized by UV–vis spectroscopy, fluorescence spectroscopy, scanning electron microscopy–energy-dispersive X-ray analysis, X-ray diffraction, Fourier transform IR spectroscopy, and high-resolution transmission electron microscopy. Their photocatalytic activity was evidenced by discoloration of the synthetic diazo dye Bismarck brown Y; ZnO–Ag nanohybrid materials had greater efficiency for decolorization of the dye compared with ZnO–Co, ZnO, and TiO2. The enhanced photocatalytic activity of the ZnO–Ag nanohybrid material is due to three important aspects: (1) the oxygen vacancies present on the ZnO surface, (2) the efficient absorption of visible light due to the interaction of the semiconductor and the surface plasmon resonance of Ag, and (3) the effective separation of charges due to the formation of the Schottky barrier between ZnO and Ag, where Ag acts as an electron trap, and thereby reduces recombination. When the ZnO–Co nanohybrid is used, the addition of Co introduces intermediate energy levels between the valence and conduction bands on the semiconductor surface, which results in a recombination that reduces the photocatalytic activity, making the azo dye decolorization less efficient

Trimetallic nanostructures: the case of AgPd–Pt multiply twinned nanoparticles

We report the synthesis, structural characterization, and atomistic simulations of AgPd–Pt trimetallic (TM) nanoparticles. Two types of structure were synthesized using a relatively facile chemical method: multiply twinned core–shell, and hollow particles. The nanoparticles were small in size, with an average diameter of 11 nm and a narrow distribution, and their characterization by aberration corrected scanning transmission electron microscopy allowed us to probe the structure of the particles at an atomistic level. In some nanoparticles, the formation of a hollow structure was also observed, that facilitates the alloying of Ag and Pt in the shell region and the segregation of Ag atoms on the surface, affecting the catalytic activity and stability. We also investigated the growth mechanism of the nanoparticles using grand canonical Monte Carlo simulations, and we have found that Pt regions grow at overpotentials on the AgPd nanoalloys, forming 3D islands at the early stages of the deposition process. We found very good agreement between the simulated structures and those observed experimentally

Effects of heavy Si doping on the structural and optical properties of n-GaN/AlN/Si(111) heterostructures

n-GaN/ AlN heterostructures were grown by molecular beam epitaxy on Si(111)substrates.The GaN films were n-type doped with silicon and the effect of doping concentration on the structural and optical properties was studied. Si doping promotes a reduction of dislocation density as revealed by x-ray data analysis and Transmission Electron Microscopy. Furthermore, a decrease in the yellow band measured by Photoluminescence Spectroscopy was observed when silicon doping concentration was increased up to 1.7 × 1019 atoms cm−3 . A particular mosaic structure was induced by the Si doping as inferred from Rutherford Backscattering measurements. The crystal quality shows a small degradation for very heavily doped samples(1.3 × 1020 atoms cm−3 )

Pseudomonas helmanticensis sp. nov., isolated from a forest soil

18 páginas, 2 figuras, 2 tablas. – The definitive versión is available at http://ijs.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.063560-0 -- MHRB is recipient of a JAE-Doc researcher contract from CSIC cofinanced by ERDF. MJC, JDFF and RM are recipients of contracts supported by this projectA bacterial strain named OHA11T was isolated in the course of a study of phosphate solubilizing bacteria occurring in a forest soil from Salamanca, Spain. The 16S rRNA gene sequence had 99.1% identity with respect to the closest relative Pseudomonas baetica a390T, and the following closest related species with 98.9 % similarity were P. jessenii, P. moorei, P. umsongensis, P. mohnii and P. koreensis, for which OHA11T was classified within genus Pseudomonas. The analysis of housekeeping genes rpoB, rpoD and gyrB confirmed its phylogenetic affiliation and showed identities lower than 95% in almost all cases with respect to the mentioned closest relatives. The strain has two polar flagella. The respiratory quinone is Q9. The major fatty acids are 16:0, 18:1 ω7c and 16:1 ω7c/ 15:0 iso 2OH in summed feature 3. The strain is oxidase, catalase and urease positive, the arginine dihydrolase system is present but nitrate reduction, β–galactosidase production and esculine hydrolysis are negative. It can grow at 31ºC and at pH 11. The DNA G+C content was 58.1 mol %. DNA-DNA hybridization results showed values lower than 49% relatedness with respect to the type strains of the seven closest related species. Therefore, the combined results of genotypic, phenotypic and chemotaxonomic data support the classification of strain OHA11 into a novel species of Pseudomonas, for which the name P. helmanticensis sp. nov. is proposed. The type strain is OHA11T (=LMG 28168T, CECT 8548T).This research was funded by MINECO (Spanish Central Government) Grant INNPACTO IPT-2011-1283-060000.Peer reviewe

Automated deep learning segmentation of high-resolution 7 T postmortem MRI for quantitative analysis of structure-pathology correlations in neurodegenerative diseases

Postmortem MRI allows brain anatomy to be examined at high resolution and to link pathology measures with morphometric measurements. However, automated segmentation methods for brain mapping in postmortem MRI are not well developed, primarily due to limited availability of labeled datasets, and heterogeneity in scanner hardware and acquisition protocols. In this work, we present a high resolution of 135 postmortem human brain tissue specimens imaged at 0.3 mm$^{3}$ isotropic using a T2w sequence on a 7T whole-body MRI scanner. We developed a deep learning pipeline to segment the cortical mantle by benchmarking the performance of nine deep neural architectures, followed by post-hoc topological correction. We then segment four subcortical structures (caudate, putamen, globus pallidus, and thalamus), white matter hyperintensities, and the normal appearing white matter. We show generalizing capabilities across whole brain hemispheres in different specimens, and also on unseen images acquired at 0.28 mm^3 and 0.16 mm^3 isotropic T2*w FLASH sequence at 7T. We then compute localized cortical thickness and volumetric measurements across key regions, and link them with semi-quantitative neuropathological ratings. Our code, Jupyter notebooks, and the containerized executables are publicly available at: https://pulkit-khandelwal.github.io/exvivo-brain-upennComment: Preprint submitted to NeuroImage Project website: https://pulkit-khandelwal.github.io/exvivo-brain-upen

Neuroanatomical and cellular degeneration associated with a social disorder characterized by new ritualistic belief systems in a TDP-C patient vs. a Pick patient

Frontotemporal dementia (FTD) is a spectrum of clinically and pathologically heterogenous neurodegenerative dementias. Clinical and anatomical variants of FTD have been described and associated with underlying frontotemporal lobar degeneration (FTLD) pathology, including tauopathies (FTLD-tau) or TDP-43 proteinopathies (FTLD-TDP). FTD patients with predominant degeneration of anterior temporal cortices often develop a language disorder of semantic knowledge loss and/or a social disorder often characterized by compulsive rituals and belief systems corresponding to predominant left or right hemisphere involvement, respectively. The neural substrates of these complex social disorders remain unclear. Here, we present a comparative imaging and postmortem study of two patients, one with FTLD-TDP (subtype C) and one with FTLD-tau (subtype Pick disease), who both developed new rigid belief systems. The FTLD-TDP patient developed a complex set of values centered on positivity and associated with specific physical and behavioral features of pigs, while the FTLD-tau patient developed compulsive, goal-directed behaviors related to general themes of positivity and spirituality. Neuroimaging showed left-predominant temporal atrophy in the FTLD-TDP patient and right-predominant frontotemporal atrophy in the FTLD-tau patient. Consistent with antemortem cortical atrophy, histopathologic examinations revealed severe loss of neurons and myelin predominantly in the anterior temporal lobes of both patients, but the FTLD-tau patient showed more bilateral, dorsolateral involvement featuring greater pathology and loss of projection neurons and deep white matter. These findings highlight that the regions within and connected to anterior temporal lobes may have differential vulnerability to distinct FTLD proteinopathies and serve important roles in human belief systems

El reto de la inclusión de los Objetivos de Desarrollo Sostenible en la formación inicial de profesores de secundaria: creación del MOOC curso cero sobre educación y ODS, inclusión en asignaturas y en trabajos fin de máster

Memoria ID-041. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2021-2022

Entre la ciencia y la cultura: la conformación de discursos médicos sobre la homosexualidad en el contexto del surgimiento del vih/sida en Costa Rica

This article seeks to analyze the ways in which medical discourse conceptualized and represented homosexuality in the years where HIV/AIDS emerged in Costa Rica. First, a theoretical reflection is made on the issue of sexuality as an object of study that constructs subjectivity at the same time. Then, an analysis of the journalistic discourses is made. The dynamics of power/knowledge in sexuality are articulated and institutionalized in the medical discourse through the media; in the case of Costa Rica both institutions, along with the Church, played a key role in the spread of abject images on male homosexuality. On the other hand, the medical discourse was not uniform; it is possible to find voices of resistance to the hegemonic position.En este artículo se analiza la manera en que el discurso médico conceptualizó y representó a la homosexualidad cuando surge el VIH/sida en Costa Rica. Se hace una reflexión teórica en torno al tema de la sexualidad como objeto de estudio, y se problematizan las diferentes maneras con las cuales se construye la subjetividad, seguidamente se analizan los discursos periodísticos. La dinámica saber/poder sexual se articula y se institucionaliza en el discurso médico a través de los medios de comunicación, ambas instituciones, junto a la Iglesia, desempeñaron un papel fundamental en la propagación de imágenes abyectas sobre la homosexualidad masculina principalmente. El discurso médico no fue homogéneo, ya que hubo voces de resistencia frente a la postura hegemónica