3,995 research outputs found
Remote video monitoring is another example of “dying on the machine” for critically ill patients
A critical appraisal and clinical application of Hardin SR, Dienemann J, Rudisill P, Mills KK. Inpatient fall prevention: use of in-room webcams. J Patient Saf. 2013 Mar;9(1):29-35. doi: 10.1097/PTS.0b013e3182753e4
A fast, dense Chebyshev solver for electronic structure on GPUs
Matrix diagonalization is almost always involved in computing the density
matrix needed in quantum chemistry calculations. In the case of modest matrix
sizes ( 5000), performance of traditional dense diagonalization
algorithms on modern GPUs is underwhelming compared to the peak performance of
these devices. This motivates the exploration of alternative algorithms better
suited to these types of architectures. We newly derive, and present in detail,
an existing Chebyshev expansion algorithm [W. Liang et al, J. Chem. Phys. 2003]
whose number of required matrix multiplications scales with the square root of
the number of terms in the expansion. Focusing on dense matrices of modest
size, our implementation on GPUs results in large speed ups when compared to
diagonalization. Additionally, we improve upon this existing method by
capitalizing on the inherent task parallelism and concurrency in the algorithm.
This improvement is implemented on GPUs by using CUDA and HIP streams via the
MAGMA library and leads to a significant speed up over the serial-only approach
for smaller ( 1000) matrix sizes. Lastly, we apply our technique to a
model system with a high density of states around the Fermi level which
typically presents significant challenges.Comment: Submitted to Journal of Chemical Physics Communication
From Frictional to Viscous Behavior: Three Dimensional Imaging and Rheology of Gravitational Suspensions
We probe the three dimensional flow structure and rheology of gravitational
(non-density matched) suspensions for a range of driving rates in a
split-bottom geometry. We establish that for sufficiently slow flows, the
suspension flows as if it were a dry granular medium, and confirm recent
theoretical modeling on the rheology of split-bottom flows. For faster driving,
the flow behavior is shown to be consistent with the rheological behavior
predicted by the recently developed "inertial number approaches for suspension
flows.Comment: 5 pages, 4 figures, accepted for Phys. Rev. E. (R
Experimental demonstration of quantum effects in the operation of microscopic heat engines
The heat engine, a machine that extracts useful work from thermal sources, is
one of the basic theoretical constructs and fundamental applications of
classical thermodynamics. The classical description of a heat engine does not
include coherence in its microscopic degrees of freedom. By contrast, a quantum
heat engine might possess coherence between its internal states. Although the
Carnot efficiency cannot be surpassed, and coherence can be performance
degrading in certain conditions, it was recently predicted that even when using
only thermal resources, internal coherence can enable a quantum heat engine to
produce more power than any classical heat engine using the same resources.
Such a power boost therefore constitutes a quantum thermodynamic signature. It
has also been shown that the presence of coherence results in the thermodynamic
equivalence of different quantum heat engine types, an effect with no classical
counterpart. Microscopic heat machines have been recently implemented with
trapped ions, and proposals for heat machines using superconducting circuits
and optomechanics have been made. When operated with standard thermal baths,
however, the machines implemented so far have not demonstrated any inherently
quantum feature in their thermodynamic quantities. Here we implement two types
of quantum heat engines by use of an ensemble of nitrogen-vacancy centres in
diamond, and experimentally demonstrate both the coherence power boost and the
equivalence of different heat-engine types. This constitutes the first
observation of quantum thermodynamic signatures in heat machines
Effect of fixed-dose subcutaneous reslizumab on asthma exacerbations in patients with severe uncontrolled asthma and corticosteroid sparing in patients with oral corticosteroid-dependent asthma : results from two phase 3, randomised, double-blind, placebo-controlled trials
BACKGROUND:
Reslizumab 3 mg/kg administered intravenously is approved for the treatment of severe eosinophilic asthma. We assessed the safety and efficacy of subcutaneous reslizumab 110 mg in two trials in patients with uncontrolled severe asthma and increased blood eosinophils. The aim was to establish whether subcutaneous reslizumab 110 mg can reduce exacerbation rates in these patients (study 1) or reduce maintenance oral corticosteroid dose in patients with corticosteroid-dependent asthma (study 2).
METHODS:
Both studies were randomised, double-blind, placebo-controlled, phase 3 studies. Entry criteria for study 1 were uncontrolled severe asthma, two or more asthma exacerbations in the previous year, a blood eosinophil count of 300 cells per μL or more (including no more than 30% patients with an eosinophil count <400 cells/μL), and at least a medium dose of inhaled corticosteroids with one or more additional asthma controllers. Patients in study 2 had severe asthma, a blood eosinophil count of 300 cells per μL or more, daily maintenance oral corticosteroid (prednisone 5-40 mg, or equivalent), and high-dose inhaled corticosteroids plus another controller. Patients were randomly assigned (1:1) to subcutaneous reslizumab (110 mg) or placebo once every 4 weeks for 52 weeks in study 1 and 24 weeks in study 2. Patients and investigators were masked to treatment assignment. Primary efficacy outcomes were frequency of exacerbations during 52 weeks in study 1 and categorised percentage reduction in daily oral corticosteroid dose from baseline to weeks 20-24 in study 2. Primary efficacy analyses were by intention to treat, and safety analyses included all patients who received at least one dose of study treatment. These studies are registered with ClinicalTrials.gov, NCT02452190 (study 1) and NCT02501629 (study 2).
FINDINGS:
Between Aug 12, 2015, and Jan 31, 2018, 468 patients in study 1 were randomly assigned to placebo (n=232) or subcutaneous reslizumab (n=236), and 177 in study 2 to placebo (n=89) or subcutaneous reslizumab (n=88). In study 1, we found no significant difference in the exacerbation rate between reslizumab and placebo in the intention-to-treat population (rate ratio 0·79, 95% CI 0·56-1·12; p=0·19). Subcutaneous reslizumab reduced exacerbation frequency compared with placebo in the subgroup of patients with blood eosinophil counts of 400 cells per μL or more (0·64, 95% CI 0·43-0·95). Greater reductions in annual exacerbation risk (p=0·0035) and longer time to first exacerbation were observed for patients with higher trough serum reslizumab concentrations. In study 2, we found no difference between placebo and fixed-dose subcutaneous reslizumab in categorised percentage reduction in daily oral corticosteroid dose (odds ratio for a lower category of oral corticosteroid use in the reslizumab group vs the placebo group, 1·23, 95% CI 0·70-2·16; p=0·47). The frequency of adverse events and serious adverse events with reslizumab were similar to those with placebo in both studies.
INTERPRETATION:
Fixed-dose (110 mg) subcutaneous reslizumab was not effective in reducing exacerbation frequency in patients with uncontrolled asthma and increased blood eosinophils (≥300 cells/μL), or in reducing the daily maintenance oral corticosteroid dose in patients with oral corticosteroid-dependent severe eosinophilic asthma. Higher exposures than those observed with 110 mg subcutaneous reslizumab are required to achieve maximal efficacy.
FUNDING:
Teva Branded Pharmaceutical Products R&D
Homomorphisms are a good basis for counting small subgraphs
We introduce graph motif parameters, a class of graph parameters that depend
only on the frequencies of constant-size induced subgraphs. Classical works by
Lov\'asz show that many interesting quantities have this form, including, for
fixed graphs , the number of -copies (induced or not) in an input graph
, and the number of homomorphisms from to .
Using the framework of graph motif parameters, we obtain faster algorithms
for counting subgraph copies of fixed graphs in host graphs : For graphs
on edges, we show how to count subgraph copies of in time
by a surprisingly simple algorithm. This
improves upon previously known running times, such as time
for -edge matchings or time for -cycles.
Furthermore, we prove a general complexity dichotomy for evaluating graph
motif parameters: Given a class of such parameters, we consider
the problem of evaluating on input graphs , parameterized
by the number of induced subgraphs that depends upon. For every recursively
enumerable class , we prove the above problem to be either FPT or
#W[1]-hard, with an explicit dichotomy criterion. This allows us to recover
known dichotomies for counting subgraphs, induced subgraphs, and homomorphisms
in a uniform and simplified way, together with improved lower bounds.
Finally, we extend graph motif parameters to colored subgraphs and prove a
complexity trichotomy: For vertex-colored graphs and , where is from
a fixed class , we want to count color-preserving -copies in
. We show that this problem is either polynomial-time solvable or FPT or
#W[1]-hard, and that the FPT cases indeed need FPT time under reasonable
assumptions.Comment: An extended abstract of this paper appears at STOC 201
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