489 research outputs found
Pressure-induced inclusion of neon in the crystal structure of a molecular Cu2(pacman) complex at 4.67 GPa
Crystals of a Cu complex of the macrocyclic Schiff-base calixpyrrole or 'Pacman' ligand, Cu2(L), do not contain any solvent-accessible void space at ambient pressure, but adsorb neon at 4.67 GPa, forming Cu2(L)·3.5Ne
Solitary coherent structures in viscoelastic shear flow: computation and mechanism
Starting from stationary bifurcations in Couette-Dean flow, we compute
nontrivial stationary solutions in inertialess viscoelastic circular Couette
flow. These solutions are strongly localized vortex pairs, exist at arbitrarily
large wavelengths, and show hysteresis in the Weissenberg number, similar to
experimentally observed ``diwhirl'' patterns. Based on the computed velocity
and stress fields, we elucidate a heuristic, fully nonlinear mechanism for
these flows. We propose that these localized, fully nonlinear structures
comprise fundamental building blocks for complex spatiotemporal dynamics in the
flow of elastic liquids.Comment: 5 pages text and 4 figures. Submitted to Physical Review Letter
Alphaflexivirus genomes in stony coral tissue loss disease-affected, disease-exposed, and disease-unexposed coral colonies in the U.S. Virgin Islands
© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Veglia, A., Beavers, K., Van Buren, E., Meiling, S., Muller, E., Smith, T., Holstein, D., Apprill, A., Brandt, M., Mydlarz, L., & Correa, A. Alphaflexivirus genomes in stony coral tissue loss disease-affected, disease-exposed, and disease-unexposed coral colonies in the U.S. Virgin Islands. Microbiology Resource Announcements, 11(2), (2022): e01199–e01121, https://doi.org/10.1128/mra.01199-21.Stony coral tissue loss disease (SCTLD) is decimating Caribbean corals. Here, through the metatranscriptomic assembly and annotation of two alphaflexivirus-like strains, we provide genomic evidence of filamentous viruses in SCTLD-affected, -exposed, and -unexposed coral colonies. These data will assist in clarifying the roles of viruses in SCTLD.This work was supported by the National Science Foundation (Biological Oceanography) award numbers 1928753 to M.E.B. and T.B.S., 1928609 to A.M.S.C., 1928817 to E.M.M., 19228771 to L.D.M., 1927277 to D.M.H., and 1928761 to A.A., as well as by VI EPSCoR (NSF numbers 0814417 and 1946412)
Resolving Sirius-like binaries with the Hubble Space Telescope
We have imaged seventeen recently discovered Sirius-like binary systems with
HST/WFPC2 and resolved the white dwarf secondary in eight cases. Most of the
implied orbital periods are of order several hundred years, but in three cases
(56 Per, Zeta Cygni and REJ1925-566) the periods are short enough that it may
be possible to detect orbital motion within a few years. It will then be
possible to derive dynamically determined masses for the white dwarfs, and
potentially these stars could be used as stringent tests of the mass-radius
relation and initial-final mass relation.Comment: To appear in Proceedings of the 12th European Workshop on White
Dwarfs, eds. H. Shipman and J. Provenca
Numerical simulation of biofilm formation in a microchannel
The focus of this paper is the numerical solution of a pore-scale model for
the growth of a permeable biofilm. The model includes water flux inside the
biofilm, different biofilm components, and shear stress on the biofilm-water
interface. To solve the resulting highly coupled system of model equations, we
propose a splitting algorithm. The Arbitrary Lagrangian Eulerian (ALE) method
is used to track the biofilm-water interface. Numerical simulations are
performed using physical parameters from the existing literature. Our
computations show the effect of biofilm permeability on the nutrient transport
and on its growth
Rifaximin Treatment in Hepatic Encephalopathy
Background
Hepatic encephalopathy is a chronically debilitating complication of hepatic cirrhosis. The efficacy of rifaximin, a minimally absorbed antibiotic, is well documented in the treatment of acute hepatic encephalopathy, but its efficacy for prevention of the disease has not been established.
Methods
In this randomized, double-blind, placebo-controlled trial, we randomly assigned 299 patients who were in remission from recurrent hepatic encephalopathy resulting from chronic liver disease to receive either rifaximin, at a dose of 550 mg twice daily (140 patients), or placebo (159 patients) for 6 months. The primary efficacy end point was the time to the first breakthrough episode of hepatic encephalopathy. The key secondary end point was the time to the first hospitalization involving hepatic encephalopathy.
Results
Rifaximin significantly reduced the risk of an episode of hepatic encephalopathy, as compared with placebo, over a 6-month period (hazard ratio with rifaximin, 0.42; 95% confidence interval [CI], 0.28 to 0.64; P
Conclusions
Over a 6-month period, treatment with rifaximin maintained remission from hepatic encephalopathy more effectively than did placebo. Rifaximin treatment also significantly reduced the risk of hospitalization involving hepatic encephalopathy. (ClinicalTrials.gov number, NCT00298038.
An efficient approach for surveillance of childhood diabetes by type derived from electronic health record data: the SEARCH for Diabetes in Youth Study
Objective To develop an efficient surveillance approach for childhood diabetes by type across 2 large US health care systems, using phenotyping algorithms derived from electronic health record (EHR) data
Contributions of demography and dispersal parameters to the spatial spread of a stage-structured insect invasion
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