Professor Christopher Sapara Grant MB.ChB, FRCS, FACS 1942–2013

Professor Grant, Head of the Department of Surgery at Sultan Qaboos University (SQU) for 15 years, died in SQU Hospital on Friday 4thOctober aged 71. Prof. Grant, who joined the College of Medicine & Health Sciences just four years after SQU opened in 1986, was one of the pioneers who made immense contributions to both medical education and the healthcare sector in Oman. Many of his former students now occupy senior positions in the Ministry of Health and the medical colleges in the country

Adopting Natural Host Immune Response Against Zoonosis

Zoonosis originated from the transmission of pathogens between species. Rapid mutation causes the pathogens to develop resistance to treatments. Thus, there is an urgent need for medications that could maintain efficacy when encountering new strains. This study aims to discern the possibility of overcoming threats from EIDs by recreating immune responses of natural hosts and reinforcing them in the human system. The methodology used is literature study, as the resarcher utilized data presented by similar studies. References will be taken from clinical trials and studies on related topics from PubMed, ResearchGate, and NCBI. Within multiple research papers, it was found that several experts support the idea of mimicking hosts' immunity through the use of interferon. Treatments with IFN-2b significantly reduce viral infection of SARS-CoV-2 in the upper respiratory tract and increase blood levels of inflammatory markers, according to research conducted in Wuhan. Similar results apply in other trials, proving that interferon managed to contain the invasion of pathogens. This is shown through a reduction in the severity of infections, the duration of viral clearance, and levels of mortality. The results conclude that the use of interferon benefits the patient’s recovery progress by mimicking the natural host’s immune response and heightening the viral clearance rate. More research needs to be done to explore the effect of excessive IFN-$\alpha$/$\beta$ usage on immunity

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 $\sim$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 dataset 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 $51.8 \pm 2.3$ $\mu$as (68\% credible intervals), with the ring thickness constrained to have an FWHM between $\sim$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 $4.8_{-0.7}^{+1.4}$ \mathrm{\mu as}, which we combine with an independent distance measurement from maser parallaxes to determine the mass of Sgr A* to be $4.0_{-0.6}^{+1.1} \times 10^6$ M$_{\odot}$.Comment: 65 pages, 35 figures, published in The Astrophysical Journal Letters on May 12, 2022. See the published paper for the full authors lis

First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization

Event Horizon Telescope (EHT) observations have revealed a bright ring of emission around the supermassive black hole at the center of the M87 galaxy. EHT images in linear polarization have further identified a coherent spiral pattern around the black hole, produced from ordered magnetic fields threading the emitting plasma. Here, we present the first analysis of circular polarization using EHT data, acquired in 2017, which can potentially provide additional insights into the magnetic fields and plasma composition near the black hole. Interferometric closure quantities provide convincing evidence for the presence of circularly polarized emission on event-horizon scales. We produce images of the circular polarization using both traditional and newly developed methods. All methods find a moderate level of resolved circular polarization across the image ($\langle|v|\rangle < 3.7\%$), consistent with the low image-integrated circular polarization fraction measured by the ALMA array ($|v_{\rm int}| < 1\%$). Despite this broad agreement, the methods show substantial variation in the morphology of the circularly polarized emission, indicating that our conclusions are strongly dependent upon the imaging assumptions because of the limited baseline coverage, uncertain telescope gain calibration, and weakly polarized signal. We include this upper limit in an updated comparison to general relativistic magnetohydrodynamic (GRMHD) simulation models. This analysis reinforces the previously reported preference for magnetically arrested accretion flow models. We find that most simulations naturally produce a low level of circular polarization consistent with our upper limit, and that Faraday conversion is likely the dominant production mechanism for circular polarization at 230 GHz in M87*.Comment: 47 pages, 31 figures, published in The Astrophysical Journal Letters on Nov. 8, 2023. See the published paper for the full authors lis

Lignes directrices pour le libre accès aux publications scientifiques et aux données de recherche dans Horizon 2020

Le service traduction de l’Inist-Cnrs a traduit les deux guides publiés par la Commission européenne pour aider les porteurs de projet du Programme-cadre Horizon 2020. Ce guide porte sur le libre accès aux publications scientifiques et aux données de la recherche. Il rappelle le contexte du libre accès et donne quelques définitions. Il détaille les obligations que doivent remplir les bénéficiaires de financement dans le cadre d’H2020 pour rendre leurs articles librement accessibles ainsi que leurs données pour les axes entrant dans le Projet pilote de libre accès aux données