277 research outputs found
Moduli Spaces for Principal Bundles in Arbitrary Characteristic
In this article, we solve the problem of constructing moduli spaces of
semistable principal bundles (and singular versions of them) over smooth
projective varieties over algebraically closed ground fields of positive
characteristic.Comment: V4: Final version, to appear in Advances in Mathematics, 69p
Weak capture of protons by protons
The cross section for the proton weak capture reaction
is calculated with wave functions obtained from a number of modern, realistic
high-precision interactions. To minimize the uncertainty in the axial two-body
current operator, its matrix element has been adjusted to reproduce the
measured Gamow-Teller matrix element of tritium decay in model
calculations using trinucleon wave functions from these interactions. A
thorough analysis of the ambiguities that this procedure introduces in
evaluating the two-body current contribution to the pp capture is given. Its
inherent model dependence is in fact found to be very weak. The overlap
integral for the pp capture is predicted to be in the range
7.05--7.06, including the axial two-body current contribution, for all
interactions considered.Comment: 17 pages RevTeX (twocolumn), 5 postscript figure
Attentive Learning of Sequential Handwriting Movements: A Neural Network Model
Defense Advanced research Projects Agency and the Office of Naval Research (N00014-95-1-0409, N00014-92-J-1309); National Science Foundation (IRI-97-20333); National Institutes of Health (I-R29-DC02952-01)
Epimacular Brachytherapy for Previously Treated Neovascular Age-Related Macular Degeneration (MERLOT) A Phase 3 Randomized Controlled Trial Presented in part at: Retina Day, American Academy of Ophthalmology Annual Meeting, November 2015, Las Vegas, Nevada.
PurposeTo assess the safety and efficacy of epimacular brachytherapy (EMB) for patients with chronic, active, neovascular age-related macular degeneration (AMD).DesignPhase 3 randomized controlled trial.ParticipantsPatients (n = 363) with neovascular AMD already receiving intravitreal ranibizumab injections.InterventionEither pars plana vitrectomy with 24-gray EMB and ongoing pro re nata (PRN) ranibizumab (n = 224) or ongoing PRN ranibizumab monotherapy (n = 119).Main Outcome MeasuresThe coprimary outcomes, at 12 months, were the number of PRN ranibizumab injections and Early Treatment of Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (VA). Secondary outcomes included the proportion of participants losing fewer than 15 ETDRS letters, angiographic total lesion size, choroidal neovascularization (CNV) size, and optical coherence tomography (OCT) foveal thickness. A predefined subgroup analysis tested the influence of baseline ocular characteristics on the response to EMB.ResultsThe mean number of PRN ranibizumab injections was 4.8 in the EMB arm and 4.1 in the ranibizumab monotherapy arm (P = 0.068). The mean VA change was −4.8 letters in the EMB arm and −0.9 letters in the ranibizumab arm (95% confidence interval of difference between groups, −6.6 to −1.8 letters). The proportion of participants losing fewer than 15 letters was 84% in the EMB arm and 92% in the ranibizumab arm (P = 0.007). In the EMB arm, the mean total lesion size increased by 1.2 mm2 versus 0.4 mm2 in the ranibizumab arm (P = 0.27). The CNV size decreased by 0.5 mm2 in the EMB arm and by 1.3 mm2 in the ranibizumab arm (P = 0.27). The OCT foveal thickness decreased by 1.0 μm in the EMB arm and by 15.7 μm in the ranibizumab arm (P = 0.43). Most subgroups favored ranibizumab monotherapy, some significantly so. One participant showed retinal vascular abnormality attributed to radiation, but otherwise safety was acceptable.ConclusionsThese results do not support the use of EMB for chronic, active, neovascular AMD. Safety is acceptable out to 12 months, but radiation retinopathy can occur later, so further follow-up is planned
Superdeformed band in 155Dy: Where does the "island" of superdeformation end?
A superdeformed band of 15 transitions has been found in the 155Dy nucleus. The measurement was performed with a backed target and the large deformation was inferred from the measured Doppler shifts. The new band displays an intensity pattern much different from typical superdeformed bands in this mass region. The dynamic moment of inertia is essentially identical to that of band 1 in 153Dy and is somewhat larger than those of the yrast superdeformed bands in 152, 154Dy, suggesting that the associated configuration has an additional N = 7, j15/2 intruder orbital occupied with respect to the 154Dy core
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
Report from the fifth international consensus meeting to harmonize core outcome measures for atopic eczema/dermatitis clinical trials (HOME initiative)
This is the report from the fifth meeting of the Harmonising Outcome Measures for Eczema initiative (HOME V). The meeting was held on 12–14 June 2017 in Nantes, France, with 81 participants. The main aims of the meeting were (i) to achieve consensus over the definition of the core domain of long-term control and how to measure it and (ii) to prioritize future areas of research for the measurement of the core domain of quality of life (QoL) in children. Moderated whole-group and small-group consensus discussions were informed by presentations of qualitative studies, systematic reviews and validation studies. Small-group allocations were performed a priori to ensure that each group included different stakeholders from a variety of geographical regions. Anonymous whole-group voting was carried out using handheld electronic voting pads according to predefined consensus rules. It was agreed by consensus that the long-term control domain should include signs, symptoms, quality of life and a patient global instrument. The group agreed that itch intensity should be measured when assessing long-term control of eczema in addition to the frequency of itch captured by the symptoms domain. There was no recommendation of an instrument for the core outcome domain of quality of life in children, but existing instruments were assessed for face validity and feasibility, and future work that will facilitate the recommendation of an instrument was agreed upon.
The Harmonising Outcome Measures for Eczema (HOME) initiative is an international group working together to develop a core outcome set (COS) for clinical trials in eczema (synonymous with atopic eczema and atopic dermatitis). HOME is coordinated from the Centre of Evidence Based Dermatology, University of Nottingham, U.K. Participation in HOME is open to anyone with an interest in outcomes for eczema. A COS is the agreed upon minimum set of instruments that should be included in all clinical trials for a particular condition. Use of a COS does not preclude using other instruments; other domains and instruments can also be included to meet the specific requirements of individual trials. COS initiatives are active across many fields of medicine and should enable better synthesis of trial data and reduce selective outcome reporting bias.
The HOME initiative follows the best current guidance on developing a COS. Four core domains have been identified: clinician-reported signs; patient-reported symptoms; quality of life; and long-term control. The core outcome measurement instruments for clinician-reported signs and patient-reported symptoms have been established: the Eczema Area and Severity Index (EASI) for measuring clinician reported signs was agreed on at the HOME III meeting, and the Patient-Oriented Eczema Measure (POEM) was chosen to measure patient-reported symptoms at the HOME IV meeting.
This is a report from the fifth consensus meeting of the HOME initiative (HOME V), which was held on 12–14 June 2017 in Nantes, France. The local organizers were Sebastien Barbarot and Jean-Francois Stalder of Nantes University Hospital, France
Spin ∼ 60 ℏ in 156Dy: Competition between collective and terminating structures at very high-spin
The highest-spin discrete states (I ∼ 60 ℏ and Ex ∼ 30 MeV) in normal deformed nuclei have been observed in the rare-earth isotope 156Dy using the 124Sn(36S,4n) reaction in conjunction with the GAMMASPHERE spectrometer. The positive parity yrast sequence appears to evolve smoothly from a prolate (collective) towards an oblate (non-collective) shape, in contrast to the sudden shape change observed in the isotone 158Er. Terminating states are identified in the negative parity sequences at Iπ = 52- and 53- and specific multi-particle-hole configurations are assigned by comparison with cranked Nilsson-Strutinsky calculations. An order of magnitude increase in the interaction strength between close lying high-spin weakly collective structures is determined compared with that found in the lower-spin strongly collective domain. These results give valuable insight into the interplay between collective and terminating structures, and their competition for yrast status in the 40 - 60 ℏ spin range
Excited states in 176, 178Hg and shape coexistence in very neutron-deficient Hg isotopes
Excited states have been observed for the first time in the neutron-deficient 176,178Hg nuclei using the recoil-decay tagging (RDT) technique in which prompt γ rays are associated with a particular isotope through a correlation with the characteristic ground state α decay. Below N = 102, the excitation energy of a rotational band built on a prolate shape (β2 ∼ 0.25) increases with decreasing mass to the point where there is no longer any evidence for its presence at low spin in 176Hg. The data are in qualitative agreement with recent mean field calculations
Distinct Assemblies of Heterodimeric Cytokine Receptors Govern Stemness Programs in Leukemia
Published first May 16, 2023Leukemia stem cells (LSC) possess distinct self-renewal and arrested differentiation properties that are responsible for disease emergence, therapy failure, and recurrence in acute myeloid leukemia (AML). Despite AML displaying extensive biological and clinical heterogeneity, LSC with high interleukin-3 receptor (IL3R) levels are a constant yet puzzling feature, as this receptor lacks tyrosine kinase activity. Here, we show that the heterodimeric IL3Rα/βc receptor assembles into hexamers and dodecamers through a unique interface in the 3D structure, where high IL3Rα/βc ratios bias hexamer formation. Importantly, receptor stoichiometry is clinically relevant as it varies across the individual cells in the AML hierarchy, in which high IL3Rα/βc ratios in LSCs drive hexamer-mediated stemness programs and poor patient survival, while low ratios mediate differentiation. Our study establishes a new paradigm in which alternative cytokine receptor stoichiometries differentially regulate cell fate, a signaling mechanism that may be generalizable to other transformed cellular hierarchies and of potential therapeutic significance.Winnie L. Kan, Urmi Dhagat, Kerstin B. Kaufmann, Timothy R. Hercus, Tracy L. Nero, Andy G.X. Zeng, John Toubia, Emma F. Barry, Sophie E. Broughton, Guillermo A. Gomez, Brooks A. Benard, Mara Dottore, Karen S. Cheung Tung Shing, Héléna Boutzen, Saumya E. Samaraweera, Kaylene J. Simpson, Liqing Jin, Gregory J. Goodall, C. Glenn Begley, Daniel Thomas, Paul G. Ekert, Denis Tvorogov, Richard J. D, Andrea, John E. Dick, Michael W. Parker, and Angel F. Lope
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