The supernova model discrimination capabilities of the WATCHMAN detector concept are explored. This cylindrical kilotonne-scale water Cherenkov detector design has been developed to detect reactor ...antineutrinos through inverse β-decay for non-proliferation applications but also has the ability to observe antineutrino bursts of core-collapse supernovae within our galaxy. Detector configurations with sizes ranging from 16 m to 22 m tank diameter and 10% to 20% PMT coverage are used to compare the expected observable antineutrino spectra based on the Nakazato, Vartanyan and Warren supernova models. These spectra are then compared to each other with a fixed event count of 100 observed inverse β-decay events and a benchmark supernova at 10 kpc distance from Earth. By comparing the expected spectra, each detector configuration's ability to distinguish is evaluated. This analysis then demonstrates that the detector design is capable of meaningful event discrimination (90+% accuracy) with 100 observed supernova antineutrino events in most configurations. Furthermore, a larger tank configuration can maintain this performance at 10 kpc distance and above, indicating that overall target mass is the main factor for such a detector's discrimination capabilities. Finally, it is estimated that the detector design can provide early warning capability for supernova bursts for the entire Milky Way in all configurations.
Introduction: There is a growing international focus on patient- centered care. A model designed to facilitate this type of care in the primary care setting is the patient-centered medical home. This ...model of care strives to be patient-focused, comprehensive, team-based, coordinated, accessible, and focused on quality and safety of care. Objective: The objective of this paper is to identify the current status and future trends of patient-centered care and the role of informatics systems and tools in facilitating this model of care. Methods: In this paper we review recent scientific literature of the past four years to identify trends and state of current evidence when it comes to patient-centered care overall, and more specifically medical homes. Results: There are several studies that indicate growth and development in seven informatics areas within patient-centered care, namely clinical decision support, registries, team care, care transitions, personal health records, telehealth, and measurement. In some cases we are still lacking large randomized clinical trials and the evidence base is not always solid, but findings strongly indicate the potential of informatics to support patient-centered care. Conclusion: Current evidence indicates that advancements have been made in implementing and evaluating patient-centered care models. Technical, legal, and practical challenges still remain. Further examination of the impact of patient-centered informatics tools and systems on clinical outcomes is needed.
Abstract
Photomultiplier tubes (PMTs) are traditionally an integral part of large underground experiments as they measure the light emission from particle interactions within the enclosed detection ...media. The BUTTON experiment will utilise around 100 PMTs to measure the response of different media suitable for rare event searches. A subset of low-radioactivity 10-inch Hamamatsu R7081 PMTs were tested, characterised, and compared to manufacture certification. This manuscript describes the laboratory tests and analysis of gain, peak-to-valley ratio and dark rate of the PMTs to give an understanding of the charge response, signal-to-noise ratio and dark noise background as an acceptance test of the suitability of these PMTs for water-based detectors. Following the evaluation of these tests, the PMT performance agreed with the manufacturer specifications. These results are imperative for modeling the PMT response in detector simulations and providing confidence in the performance of the devices once installed in the detector underground.
A reconstruction algorithm has been developed to capitalize on advances in Cherenkov technology for reactor antineutrino detection.
Large gadolinium-doped water (Gd-H2O) Cherenkov detectors are a ...developing technology which use Gd loading to increase the visibility of the neutrons produced in inverse beta decay (IBD) interactions, which produce positron–neutron pairs coincident in time and space. In this paper, we describe the reconstruction which uses the combined light from both events in an IBD pair to accurately reconstruct the interaction vertex.
Using simulation, the algorithm has been applied to the reconstruction of reactor antineutrinos in Gd-H2O and in Gd-doped water-based liquid scintillator (Gd-WbLS), an advanced detector medium which is also currently in development.
Compared to a single-event reconstruction, the combined reconstruction improves vertex resolution for reactor IBD positrons by up to a factor of 4.5 at the lowest energies. IBD-neutron vertex resolution was found to improve by more than 30% in most instances.
Powerful background rejection with the coincidence reconstruction can be achieved by requiring a minimum quality of fit. This was found to reject up to 94% of accidental coincidences of uncorrelated background events, while retaining at least 97.5% of the IBD signal pairs.
Abstract
The supernova model discrimination capabilities of the WATCHMAN detector concept are explored. This cylindrical kilotonne-scale water Cherenkov detector design has been developed to detect ...reactor antineutrinos through inverse
β
-decay for non-proliferation applications but also has the ability to observe antineutrino bursts of core-collapse supernovae within our galaxy. Detector configurations with sizes ranging from 16 m to 22 m tank diameter and 10% to 20% PMT coverage are used to compare the expected observable antineutrino spectra based on the Nakazato, Vartanyan and Warren supernova models. These spectra are then compared to each other with a fixed event count of 100 observed inverse
β
-decay events and a benchmark supernova at 10 kpc distance from Earth. By comparing the expected spectra, each detector configuration's ability to distinguish is evaluated. This analysis then demonstrates that the detector design is capable of meaningful event discrimination (90+% accuracy) with 100 observed supernova antineutrino events in most configurations. Furthermore, a larger tank configuration can maintain this performance at 10 kpc distance and above, indicating that overall target mass is the main factor for such a detector's discrimination capabilities. Finally, it is estimated that the detector design can provide early warning capability for supernova bursts for the entire Milky Way in all configurations.
Studies of virulence determinants in the bacterial phytopathogen Erwinia amylovora, the cause of devastating fire blight disease in apple and pear, have shown that HsvA, a putative amidinotransferase ...enzyme located in the Hrp pathogenicity island, is required for systemic infection in apple. However, the mechanism by which HsvA contributes to virulence is unclear. To investigate the role of HsvA in virulence, we carried out a series of biochemical and structural studies to characterize the amidinotransferase activity of HsvA. We found that HsvA displays a preference for linear aliphatic polyamines as the amidino acceptor substrate, especially for spermidine and putrescine (Km values of 33 μm and 3.9 mm, respectively). The three-dimensional structure, determined at 2.30 Å resolution using X-ray crystallography, revealed that the overall architecture of HsvA is similar to that of the human arginine–glycine amidinotransferase in the creatine biosynthesis pathway. The active site is located in the core of the protein at the base of a long, narrow substrate access channel. Specific amino acids near the entrance of the channel may serve as major determinants of the substrate specificity, including a glutamate residue at the rim of the channel entrance that appears to be positioned to interact with the distal primary amine in the putrescine substrate as well as the internal and distal amines in the spermidine substrate. These results suggest potential in vivo functions for HsvA as a virulence factor in fire blight and may also provide a basis for strategies to control fire blight by inhibiting HsvA activity.
Background: Slipped capital femoral epiphysis (SCFE) results in alterations to femoral head anatomy, predisposing patients to degenerative hip disease at a young age. Total hip arthroplasty (THA) is ...performed to relieve symptoms and improve function. However, it can be associated with a variable outcomes and little evidence exists on the functional outcomes, complications and revision rate following such procedures. Purpose: The aim of this systematic review is to determine the safety and effectiveness of performing hip arthroplasty in patients with degenerative hips secondary to SCFE. Methodology: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature review was conducted of MEDLINE and Embase. Both single-arm and comparative studies were included. The outcomes of interest were functional scores, post-operative complications and revision rate. Results: Six studies fit the inclusion criteria. Of these, five were retrospective single-arm studies and one was a retrospective comparative study based on registry data. All studies reported significant improvement in hip function and quality of life after THA. An overall revision rate of 11.9% was reported, occurring at a mean of 6.5 years (0.75–18.7 years). THA in patients after SCFE leads to improved functional outcomes that are comparable to patients receiving THA for osteoarthritis. The revision rate appears to be higher than is reported in patients undergoing THA for osteoarthritis at mid-term follow-up. Further prospective comparative studies are needed to evaluate the efficacy of the treatment in more detail.
Cite this article: EFORT Open Rev 2021;6:539-544. DOI: 10.1302/2058-5241.6.200038
Collagenous colitis is a form of microscopic colitis that results in chronic watery diarrhea. The disorder predominantly affects middle-aged women, and its course tends to be benign. It is not ...thought to be a precursor of overt inflammatory bowel disease; however, apparent progression to ulcerative colitis has been reported on one previous occasion. We describe two further patients with symptoms and histologic features of collagenous colitis who subsequently developed ulcerative colitis. The first patient developed ulcerative colitis 13 months after diagnosis of collagenous colitis, although she gave a 23-year history of profuse watery diarrhea, which had not been adequately investigated. In the second patient, collagenous colitis was diagnosed soon after the onset of watery diarrhea, and 12 months later, progression to ulcerative colitis was documented. Both patients tested positive for perinuclear antineutrophil cytoplasmic antibody after they developed ulcerative colitis; the first patient was initially negative. In conclusion, these two cases, in addition to the one other in the literature, suggest that collagenous colitis and ulcerative colitis may represent extremes in the spectrum of inflammatory bowel disease and that collagenous colitis may evolve to ulcerative colitis. Therefore, progression to ulcerative colitis should be considered in any patient with known collagenous colitis whenever bloody diarrhea occurs, or if red cells, as well as white cells, are noted on stool microscopy.
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