21 research outputs found
The Orbiting Astrophysical Spectrometer In Space (OASIS)
The Orbiting Astrophysical Observatory In Space (OASIS) is an Advanced Concept currently under study at NASA as a mission for the next decade. The goal of the OASIS mission is to identify a local site or sites where galactic cosmic rays (GCR) originate and are accelerated. The mission will also allow GCR data to be used to investigate how elements are made and distributed in the galaxy and to improve our understanding of supernovae and the nucleosynthesis of the heavy elements. OASIS consists of two instruments that provide complementary data on the location and nature of the source(s) through investigating the composition of ultra-heavy nuclei ( ) and the energy spectrum of electrons.
In particular OASIS will measure the relative abundances in the actinide group ( ) to determine the age of the -process material in GCRs. The presence of young r-process material would indicate that GCRs are a sample of the interstellar
medium in OB associations. OASIS will measure the electron spectrum to 10 TeV. The energy where this spectrum ends will tell us the distance to the nearest GCR source(s). OASIS will look for spectral features and anisotropy in the high energy electron spectrum that are expected to appear when only a few of the nearest astrophysical sources can contribute to the electron flux. Spectral features may also suggest dark matter decay products. We anticipate that these
measurements will lead to the identification of the nearest cosmic ray electron source and provide a crucial test of the OB association model for the origin of GCR nuclei
Secondary Electron-Capture Clock Isotopes as a Probe of Reacceleration
Cosmic rays that are produced by nuclear interactions during propagation and decay only by electron capture can be used to determine the level of cosmic ray reacceleration that has occurred. The high resolution, large statistical sample of cosmic rays collected by the Cosmic Ray Isotope Spectrometer (CRIS) aboard the Advanced Composition Explorer (ACE) spacecraft provides a data set that allows precision measurements of these isotopic abundances. We discuss electron capture decay, the signatures of
reacceleration, and the sensitivity with which reacceleration models can be tested
Genes associated with pathogenicity of avian Escherichia coli (APEC) isolated from respiratory cases of poultry
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
Background:
Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19.
Methods:
This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.
Findings:
Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79).
Interpretation:
In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes.
Funding:
UK Research and Innovation (Medical Research Council) and National Institute of Health Research
Controls of fluid chemistry and complexation on rare earth element contents of anhydrite from the PACMANUS subseafloor hydrothermal system, Manus Basin, Papua New Guinea
A model for estimating abundance of cattle grub (Diptera: Oestridae) from the proportion of uninfested cattle as determined by serology*
REE and Sr isotope geochemistry of anhydrite from the PACMANUS subseafloor hydrothermal system
Light-mediated antifungal activity of Echinacea extracts
This study demonstrated that plant extracts containing acetylenic isobutylamides and polyacetylenes, previously reported as occurring in Echinacea, have phototoxic antimicrobial activity against fungi, including clinically relevant pathogenic fungi. Results show that hexane extracts of Echinacea variably inhibit growth of yeast strains of Saccharomyces cerevisiae, Candida shehata, C. kefyr, C. albicans, C. steatulytica and C. tropicalis under near UV irradiation (phototoxicity) and to a lower extent without irradiation (conventional antifungal acti