PTF11eon/SN2011dh: Discovery of a Type IIb Supernova From a Compact Progenitor in the Nearby Galaxy M51

On May 31, 2011 UT a supernova (SN) exploded in the nearby galaxy M51 (the Whirlpool Galaxy). We discovered this event using small telescopes equipped with CCD cameras, as well as by the Palomar Transient Factory (PTF) survey, and rapidly confirmed it to be a Type II supernova. Our early light curve and spectroscopy indicates that PTF11eon resulted from the explosion of a relatively compact progenitor star as evidenced by the rapid shock-breakout cooling seen in the light curve, the relatively low temperature in early-time spectra and the prompt appearance of low-ionization spectral features. The spectra of PTF11eon are dominated by H lines out to day 10 after explosion, but initial signs of He appear to be present. Assuming that He lines continue to develop in the near future, this SN is likely a member of the cIIb (compact IIb; Chevalier and Soderberg 2010) class, with progenitor radius larger than that of SN 2008ax and smaller than the eIIb (extended IIb) SN 1993J progenitor. Our data imply that the object identified in pre-explosion Hubble Space Telescope images at the SN location is possibly a companion to the progenitor or a blended source, and not the progenitor star itself, as its radius (~10^13 cm) would be highly inconsistent with constraints from our post-explosion photometric and spectroscopic data

First operational BRDF, albedo nadir reflectance products from MODIS

With the launch of NASA’s Terra satellite and the MODerate Resolution Imaging Spectroradiometer (MODIS), operational Bidirectional Reflectance Distribution Function (BRDF) and albedo products are now being made available to the scientific community. The MODIS BRDF/Albedo algorithm makes use of a semiempirical kernel-driven bidirectional reflectance model and multidate, multispectral data to provide global 1-km gridded and tiled products of the land surface every 16 days. These products include directional hemispherical albedo (black-sky albedo), bihemispherical albedo (white-sky albedo), Nadir BRDF-Adjusted surface Reflectances (NBAR), model parameters describing the BRDF, and extensive quality assurance information. The algorithm has been consistently producing albedo and NBAR for the public since July 2000. Initial evaluations indicate a stable BRDF/Albedo Product, where, for example, the spatial and temporal progression of phenological characteristics is easily detected in the NBAR and albedo results. These early beta and provisional products auger well for the routine production of stable MODIS-derived BRDF parameters, nadir reflectances, and albedos for use by the global observation and modeling communities

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Robotic spectroscopy with the Liverpool telescope and its applications to be star variability

The work presented in this thesis provides an account of the assembly, testing (with subsequent empirical characterisation) and instrument software development phases undertaken by the author as part of the commissioning process for the Liverpool Tele- scope's fibre-fed integral field unit spectrograph, FRODOSpec. The software developed comprises a fully autonomous data reduction pipeline that has since been integrated into the processing workftow for all observations taken with FRODOSpec. Along with producing a set of science-ready data products, the pipeline constructs a composite raster image of the reduction products which is made available online for quick preview, allowing users to assess their observation shortly after it's taken place and without needing to perform any time-consuming reduction of their own. Coupled with the robotic nature of the Liverpool Telescope, FRODOSpec and its reduction pipeline provide a unique observational tool, and their conjunct use is particularly well suited for programmes within the field of observational time domain astrophysics where rapid response and analysis is an asset. In addition to the commissioning of FRODOSpec, a study into the variability of a 'sam- ple of 58 Be stars has been conducted. Building upon a dataset first observed with the INT ten years ago, four further epochs of data have been obtained using FRO- DOSpec and reduced using its pipeline. A method to assess the frequency of targets changing between disk emission and non-emission phases using the Ha equivalent width is explained and applied to consecutive epochs, with the resulting timescale for phase changing events predicted to be considerably larger than the current paradigm of several years to decades. The reduced frequency observed fon these events would consequently need to be explained by any theoretical model of disk decretion and dis- sipation in these stars. A corollary to this work also finds that partial variability of Ha emission is more fre- quently observed in stars with earlier spectral subtypes, indicating that the circum- stellar disk in later subtypes may be more stable over the timescales probed in this ) study.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Development of an halbach array for a gisaxs instrument

For nanoparticle research, a Halbach array device has been developed that allows the dynamic reproducible definition of the magnet field strength and orientation at a sample. The maximum achievable field strength is 0.5 Tesla. The main application of the Halbach array will be in the sample environment of the GISAXS instrument GALAXI.The magnet field orientation and strength are defined by rotating permanent magnets with stepper motors. Control of the stepper motors is implemented with a S7-1500 PLC in the ET200SP form factor. All field computations are executed in Nicos which controls the device. One challenge in development is the dynamic positioning of magnets due to changing forces. For vacuum applications, a water-cooling system has been implemented that allows the control of the motor temperatures. Design and implementation of the Halbach array device as well as future plans will be presented

Designing a framework for the delivery of collaborative musculoskeletal care involving chiropractors and physicians in community-based primary care

Abstract Strategies have been proposed to facilitate collaboration between conventional health care providers in primary care. However, little is known if these are transferable to CAM health care providers. We designed a qualitative study to articulate a conceptual model to advance the interprofessional collaboration between physicians and chiropractors within community-based primary care in Ontario, Canada. Data obtained from 16 key informants and eight focus groups, with a range of professionals including chiropractors, physicians and academia as well as patients, informed the development our framework. The framework included processed-based factors that clustered under three categories: communication, practice parameters, and service delivery; presumed necessary to address challenges and optimize benefits of collaboration. The development of this framework may help understand and promote interprofessional collaborative practice and contribute to the understanding of how CAM may participate in mainstream healthcare