10,729 research outputs found
Entanglement can completely defeat quantum noise
We describe two quantum channels that individually cannot send any
information, even classical, without some chance of decoding error. But
together a single use of each channel can send quantum information perfectly
reliably. This proves that the zero-error classical capacity exhibits
superactivation, the extreme form of the superadditivity phenomenon in which
entangled inputs allow communication over zero capacity channels. But our
result is stronger still, as it even allows zero-error quantum communication
when the two channels are combined. Thus our result shows a new remarkable way
in which entanglement across two systems can be used to resist noise, in this
case perfectly. We also show a new form of superactivation by entanglement
shared between sender and receiver.Comment: 4 pages, 1 figur
Potentially Inappropriate Prescribing of Proton Pump Inhibitors Among Older Patients in the US
The American Geriatrics Society list of Potentially Inappropriate Medication (Beers Criteria) use in older adults (\u3e64-years) includes Proton Pump Inhibitors (PPIs), and specifically cautions against their use for \u3e8 weeks. PPIs are prescribed to reduce the production of stomach acid, however there is strong evidence older adults are at risk of infection and bone loss from prolonged exposure to PPIs. This study used data from the 2017 Medical Expenditure Panel Survey (MEPS) and the FDA Adverse Event Report System (FAERS, as of June 30, 2019) to characterize the current prescribing practices of PPIs to older adults and the risks those patients may face. 4,288 patients \u3e64-years were included in this study, weighted to represent over 46 million Americans. Of these, 19.6% had been prescribed a PPI in 2017, and 10.05% had a long-term (\u3e8 week) prescription. Results from a generalized linear model using a quasibinomial link function demonstrated that patients with arthritis (adjusted-OR: 1.52, 95% CI: 1.17-1.98) and asthma (adjusted-OR: 1.73, 95% CI: 1.24-2.41) were more likely to have long-term PPI use, as were patients with 5+ other prescriptions (adjusted-OR: 4.31, 95% CI: 2.71-6.85). The adjusted odds ratios (OR) did not differ by age, gender, income, or education-level. For all PPIs, 28,031 (age\u3e64) adverse event (AE) cases were found in FAERS. The most commonly reported AEs were gastrointestinal disorders, and renal or urinary disorders, which appeared in 50% of included cases. Overall, our study reported current risks from and potential predictors of long-term PPI use among older adults
Invariant information and complementarity in high-dimensional states
Using a generalization of the invariant information introduced by Brukner and
Zeilinger [Phys. Rev. Lett. \textbf{83}, 3354 (1999)] to high-dimensional
systems, we introduce a complementarity relation between the local and nonlocal
information for systems under the isolated environment, where
is prime or the power of prime. We also analyze the dynamics of the local
information in the decoherence process.Comment: 4 pages, 2 figure
Archiving and Delivery of 3DTI Rehabilitation Sessions
In this paper we present CyPhy: a cyber-physiotherapy system that brings daily rehabilitation to patient’s home with supervision from trained therapist. With its archiving and delivery features, CyPhy is able to 1) capture and record RGB-D and physiotherapy-related medical sensing data streams in home environment; 2) provide efficient storage for rehabilitation session recordings; 3) provide fast metadata analysis over stored sessions for review recommendation; 4) adaptively deliver rehabilitation session under different networking capabilities; 5) support smooth viewpoint changing during 3D video streaming with scene rendering schemes tailored for devices with different bandwidth and power limitations; and 6) provide platform-independent streaming client for various mobile and PC environments
On Coding for Reliable Communication over Packet Networks
We present a capacity-achieving coding scheme for unicast or multicast over
lossy packet networks. In the scheme, intermediate nodes perform additional
coding yet do not decode nor even wait for a block of packets before sending
out coded packets. Rather, whenever they have a transmission opportunity, they
send out coded packets formed from random linear combinations of previously
received packets. All coding and decoding operations have polynomial
complexity.
We show that the scheme is capacity-achieving as long as packets received on
a link arrive according to a process that has an average rate. Thus, packet
losses on a link may exhibit correlation in time or with losses on other links.
In the special case of Poisson traffic with i.i.d. losses, we give error
exponents that quantify the rate of decay of the probability of error with
coding delay. Our analysis of the scheme shows that it is not only
capacity-achieving, but that the propagation of packets carrying "innovative"
information follows the propagation of jobs through a queueing network, and
therefore fluid flow models yield good approximations. We consider networks
with both lossy point-to-point and broadcast links, allowing us to model both
wireline and wireless packet networks.Comment: 33 pages, 6 figures; revised appendi
Entropic uncertainty relations and entanglement
We discuss the relationship between entropic uncertainty relations and
entanglement. We present two methods for deriving separability criteria in
terms of entropic uncertainty relations. Especially we show how any entropic
uncertainty relation on one part of the system results in a separability
condition on the composite system. We investigate the resulting criteria using
the Tsallis entropy for two and three qubits.Comment: 8 pages, 3 figures, v2: small change
Determinants of a transcriptionally competent environment at the GM-CSF promoter
Granulocyte macrophage-colony stimulating factor
(GM-CSF) is produced by T cells, but not B cells,
in response to immune signals. GM-CSF gene
activation in response to T-cell stimulation requires
remodelling of chromatin associated with the
gene promoter, and these changes do not occur in
B cells. While the CpG methylation status of the
murine GM-CSF promoter shows no correlation with
the ability of the gene to respond to activation, we
find that the basal chromatin environment of the
gene promoter influences its ability to respond to
immune signals. In unstimulated T cells but not B
cells, the GM-CSF promoter is selectively marked
by enrichment of histone acetylation, and association
of the chromatin-remodelling protein BRG1.
BRG1 is removed from the promoter upon activation
concomitant with histone depletion and BRG1
is required for efficient chromatin remodelling and
transcription. Increasing histone acetylation at
the promoter in T cells is paralleled by increased
BRG1 recruitment, resulting in more rapid chromatin
remodelling, and an associated increase in GM-CSF
mRNA levels. Furthermore, increasing histone
acetylation in B cells removes the block in chromatin
remodelling and transcriptional activation
of the GM-CSF gene. These data are consistent
with a model in which histone hyperacetylation
and BRG1 enrichment at the GM-CSF promoter,
generate a chromatin environment competent
to respond to immune signals resulting in gene
activation
Defining the chromatin signature of inducible genes in T cells
BACKGROUND Specific chromatin characteristics, especially the modification status of the core histone proteins, are associated with active and inactive genes. There is growing evidence that genes that respond to environmental or developmental signals may possess distinct chromatin marks. Using a T cell model and both genome-wide and gene-focused approaches, we examined the chromatin characteristics of genes that respond to T cell activation. RESULTS To facilitate comparison of genes with similar basal expression levels, we used expression-profiling data to bin genes according to their basal expression levels. We found that inducible genes in the lower basal expression bins, especially rapidly induced primary response genes, were more likely than their non-responsive counterparts to display the histone modifications of active genes, have RNA polymerase II (Pol II) at their promoters and show evidence of ongoing basal elongation. There was little or no evidence for the presence of active chromatin marks in the absence of promoter Pol II on these inducible genes. In addition, we identified a subgroup of genes with active promoter chromatin marks and promoter Pol II but no evidence of elongation. Following T cell activation, we find little evidence for a major shift in the active chromatin signature around inducible gene promoters but many genes recruit more Pol II and show increased evidence of elongation. CONCLUSIONS These results suggest that the majority of inducible genes are primed for activation by having an active chromatin signature and promoter Pol II with or without ongoing elongation
Divergence and Shannon information in genomes
Shannon information (SI) and its special case, divergence, are defined for a
DNA sequence in terms of probabilities of chemical words in the sequence and
are computed for a set of complete genomes highly diverse in length and
composition. We find the following: SI (but not divergence) is inversely
proportional to sequence length for a random sequence but is length-independent
for genomes; the genomic SI is always greater and, for shorter words and longer
sequences, hundreds to thousands times greater than the SI in a random sequence
whose length and composition match those of the genome; genomic SIs appear to
have word-length dependent universal values. The universality is inferred to be
an evolution footprint of a universal mode for genome growth.Comment: 4 pages, 3 tables, 2 figure
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