Can a combination of the conformal thin-sandwich and puncture methods yield binary black hole solutions in quasi-equilibrium?

We consider combining two important methods for constructing quasi-equilibrium initial data for binary black holes: the conformal thin-sandwich formalism and the puncture method. The former seeks to enforce stationarity in the conformal three-metric and the latter attempts to avoid internal boundaries, like minimal surfaces or apparent horizons. We show that these two methods make partially conflicting requirements on the boundary conditions that determine the time slices. In particular, it does not seem possible to construct slices that are quasi-stationary and avoid physical singularities and simultaneously are connected by an everywhere positive lapse function, a condition which must obtain if internal boundaries are to be avoided. Some relaxation of these conflicting requirements may yield a soluble system, but some of the advantages that were sought in combining these approaches will be lost.Comment: 8 pages, LaTeX2e, 2 postscript figure

Material-independent crack arrest statistics: Application to indentation experiments

An extensive experimental study of indentation and crack arrest statistics is presented for four different brittle materials (alumina, silicon carbide, silicon nitride, glass). Evidence is given that the crack length statistics can be described by a universal (i.e. material independent) distribution. The latter directly derives from results obtained when modeling crack propagation as a depinning phenomenon. Crack arrest (or effective toughness) statistics appears to be fully characterized by two parameters, namely, an asymptotic crack length (or macroscopic toughness) value and a power law size dependent width. The experimental knowledge of the crack arrest statistics at one given scale thus gives access to its knowledge at all scales

Crystal structure of the H256A mutant of rat testis fructose-6- phosphate,2-kinase/fructose-2,6-bisphosphatase: Fructose 6-phosphate in the active site leads to mechanisms for both mutant and wild type bisphosphatase activities

Fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase (Fru-6-P,2- kinase/Fru-2,6-Pase) is a bifunctional enzyme, catalyzing the interconversion of β-D-fructose-6-phosphate (Fru-6-P) and fructose-2,6-bisphosphate (Fru- 2,6-P2) at distinct active sites. A mutant rat testis isozyme with an alanine replacement for the catalytic histidine (H256A) in the Fru-2,6-Pase domain retains 17% of the wild type activity (Mizuguchi, H., Cook, P. F., Tai, C-H., Hasemann, C. A., and Uyeda, K. (1998) J. Biol. Chem. 274, 2166- 2175). We have solved the crystal structure of H256A to a resolution of 2.4 Å by molecular replacement. Clear electron density for Fru-6-P is found at the Fru-2,6-Pase active site, revealing the important interactions in substrate/product binding. A superposition of the H256A structure with the RT2K-Wo structure reveals no significant reorganization of the active site resulting from the binding of Fru-6-P or the H256A mutation. Using this superposition, we have built a view of the Fru-2,6-P2-bound enzyme and identify the residues responsible for catalysis. This analysis yields distinct catalytic mechanisms for the wild type and mutant proteins. The wild type mechanism would lead to an inefficient transfer of a proton to the leaving group Fru-6-P, which is consistent with a view of this event being rate-limiting, explaining the extremely slow turnover (0.032 s-1) of the Fru-2,6-Pase in all Fru-6-P,2-kinase/Fru-2,6-Pase isozymes

Sleep Health, Individual Characteristics, Lifestyle Factors, and Marathon Completion Time in Marathon Runners: A Retrospective Investigation of the 2016 London Marathon

Despite sleep health being critically important for athlete performance and well-being, sleep health in marathoners is understudied. This foundational study explored relations between sleep health, individual characteristics, lifestyle factors, and marathon completion time. Data were obtained from the 2016 London Marathon participants. Participants completed the Athlete Sleep Screening Questionnaire (ASSQ) along with a brief survey capturing individual characteristics and lifestyle factors. Sleep health focused on the ASSQ sleep difficulty score (SDS) and its components. Linear regression computed relations among sleep, individual, lifestyle, and marathon variables. The analytic sample (N = 943) was mostly male (64.5%) and young adults (66.5%). A total of 23.5% of the sample reported sleep difficulties (SDS ≥ 8) at a severity warranting follow-up with a trained sleep provider. Middle-aged adults generally reported significantly worse sleep health characteristics, relative to young adults, except young adults reported significantly longer sleep onset latency (SOL). Sleep tracker users reported worse sleep satisfaction. Pre-bedtime electronic device use was associated with longer SOL and longer marathon completion time, while increasing SOL was also associated with longer marathon completion. Our results suggest a deleterious influence of pre-bedtime electronic device use and sleep tracker use on sleep health in marathoners. Orthosomnia may be a relevant factor in the relationship between sleep tracking and sleep health for marathoners

Membranous Glomerulonephritis With Crescents.

INTRODUCTION: Membranous glomerulonephritis (MGN) is rarely associated with necrotizing and crescentic glomerulonephritis (NCGN). METHODS: We report the clinical and pathologic findings in 15 patients with MGN and NCGN associated with anti-neutrophil cytoplasm antibodies (ANCAs), anti-glomerular basement membrane (GBM), or anti-phospholipase A2 receptor (PLA2R) antibodies. RESULTS: The cohort consisted of 15 patients: 7 males and 8 females with a median age of 63 years (range: 18-79). In 12 of 15 patients, MGN and NCGN were diagnosed at the time of the biopsy, and in 3 cases, MGN predated the NCGN. ANCA was positive in 7 cases (6 MPO myeloperoxidase (MPO)-ANCA and 1 PR3-ANCA), anti-GBM antibodies were detected in 5 cases, and anti-PLA2R antibodies were found in 2 cases. One case was negative for all antibodies. Microscopic hematuria was present in all but one patient who was anuric, and median urinary protein-to-creatinine ratio was 819.5 mg/mmol (range: 88-5600). Pathologic evaluation revealed MGN and NCGN with crescents involving 28% of glomeruli (median; range: 5%-100%). Follow-up was available for all 15 patients; all were treated with steroids; 10 with cyclophosphamide, and 6 also received rituximab. At a median follow-up of 72 months, 9 had stabilization or improvement of renal function, 6 had progressed to end-stage renal disease, and 4 died during the follow-up period. CONCLUSION: MGN with crescents associated with ANCAs or anti-GBM antibodies is a rare dual glomerulopathy. Patients present with heavy proteinuria, microscopic hematuria, and acute kidney injury and should be treated for a rapidly progressive glomerulonephritis. Prognosis is variable, and 40% of patients progress to end-stage renal disease

Interpretating observations of ion cyclotron emission from Large Helical Device plasmas with beam-injected ion populations

Ion cyclotron emission (ICE) is detected from all large toroidal magnetically confined fusion (MCF) plasmas. It is a form of spontaneous suprathermal radiation, whose spectral peak frequencies correspond to sequential cyclotron harmonics of energetic ion species, evaluated at the emission location. We first present an account of the worldwide experimental ICE database, highlighting the phenomenological importance of the value of the ratio of energetic ion velocity v<sub>energetic</sub> to the local Alfvén speed V<sub>A</sub>. We then focus on ICE measurements from heliotron-stellarator hydrogen plasmas, heated by energetic proton neutral beam injection (NBI) in the Large Helical Device, for which v<sub>energetic</sub>/V<sub>A</sub> takes values both larger (super-Alfvénic) and smaller (sub-Alfvénic) than unity. The collective relaxation of the NBI proton population, together with the thermal plasma, is studied using a particle-in-cell (PIC) code. This evolves the Maxwell-Lorentz system of equations for hundreds of millions of kinetic gyro-orbit-resolved ions and fluid electrons, self-consistently with the electric and magnetic fields. For LHD-relevant parameter sets, the spatiotemporal Fourier transforms of the fields yield, in the nonlinear saturated regime, good computational proxies for the observed ICE spectra in both the super-and sub-Alfvénic regimes for NBI protons. At early times in the PIC treatment, the computed growth rates correspond to analytical linear growth rates of the magnetoacoustic cyclotron instability (MCI), which was previously identified to underly ICE from tokamak plasmas. The spatially localised PIC treatment does not include toroidal effects or geometry. Its success in simulating ICE spectra from tokamak and, here, heliotron-stellarator plasmas suggests that the plasma parameters and ion energetic distribution at the emission location suffice to determine the ICE phenomenology. The capability to span the super-Alfvénic and sub-Alfvénic energetic ion regimes is a generic challenge in interpreting MCF plasma physics, and it is encouraging that this first principles computational treatment of ICE has now achieved this

The ethics of future trials: qualitative analysis of physicians' decision making

Background: The decision to conduct a randomized controlled trial (RCT) in a field raises ethical as well as scientific issues. From the clinical equipoise literature, future trials are justifiable if there is ”honest, professional disagreement in the community of expert practitioners as to the preferred treatment”. Empirical data are sparse about how clinicians apply the principles of equipoise to the justification of future RCTs. For example, selective decontamination of the digestive tract (SDD) is not widely used in critical care practice despite the strength of the evidence base and therefore provides a unique opportunity to learn how clinicians think about the ethics of further RCTs in critical care. Methods: In an international interview study of views of healthcare professionals about SDD, we undertook a secondary analysis of qualitative data collected using a Theoretical Domains Framework of clinical behaviour. We adopted a general descriptive approach to explore how physicians determined whether another RCT of SDD is ethical. Following a constant comparison approach, three investigators reviewed 54 purposively chosen transcripts from three international regions. We interpreted the data using thematic analysis. Results: We grouped participants’ responses into four inter-related themes: 1) cultural norms about evidence and practice within healthcare; 2) personal views about what evidence is current or applicable; 3) the interpersonal and relational nature of professional decision making locally; and 4) an a priori commitment to future trials. The analysis also identified several unresolved tensions regarding when a future RCT should be pursued. These tensions focused on a clash between potential benefits to current individual patients and potential future harms to patients more broadly. Conclusions: Our study suggests that ethical decision making about future RCTs in the field of SDD does not rely strongly on appeals to evidence, even when the quality of the evidence is reasonably high. Rather, “extra-evidential” reasons, including social, professional, and relational factors, seem to influence opinions regarding the ethics of future trials. Further work is required to see if these conclusions are applicable to other clinical topics and settings

P2X7 receptor‐mediated Nlrp3‐inflammasome activation is a genetic determinant of macrophage‐dependent crescentic glomerulonephritis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141169/1/jlb0127-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141169/2/jlb0127.pd

Searching for periodicities in the MACHO light curve of LMC X-2

Using the exceptional long-term monitoring capabilities of the MACHO project, we present here the optical history of LMC X-2 for a continuous 6-yr period. These data were used to investigate the previously claimed periodicities for this source of 8.15 h and 12.54 d : we find upper amplitude limits of 0.10 mag and 0.09 mag, respectively.Comment: 4 pages, 4 figures. Minor changes, including title. MNRAS, in pres