161 research outputs found
Complete elimination of information leakage in continuous-variable quantum communication channels
In all lossy communication channels realized to date, information is
inevitably leaked to a potential eavesdropper. Here we present a communication
protocol that does not allow for any information leakage to a potential
eavesdropper in a purely lossy channel. By encoding information into a
restricted Gaussian alphabet of squeezed states we show, both theoretically and
experimentally, that the Holevo information between the eavesdropper and the
intended recipient can be exactly zero in a purely lossy channel while
minimized in a noisy channel. This result is of fundamental interest, but might
also have practical implications in extending the distance of secure quantum
key distribution.Comment: 9 pages, 5 figure
Recommended from our members
Mechanistic Basis for High Reactivity of (salen)Co–OTs in the Hydrolytic Kinetic Resolution of Terminal Epoxides
The (salen)Co(III)-catalyzed hydrolytic kinetic resolution (HKR) of terminal epoxides is a bimetallic process with a rate controlled by partitioning between a nucleophilic (salen)Co–OH catalyst and a Lewis acidic (salen)Co–X catalyst. The commonly used (salen)Co–OAc and (salen)Co–Cl precatalysts undergo complete and irreversible counterion addition to epoxide during the course of the epoxide hydrolysis reaction, resulting in quantitative formation of weakly Lewis acidic (salen)Co–OH, and severely diminished reaction rates in the late stages of HKR reactions. In contrast, (salen)Co–OTs maintains high reactivity over the entire course of HKR reactions. We describe here an investigation of catalyst partitioning with different (salen)Co–X precatalysts, and demonstrate that counterion addition to epoxide is reversible in the case of the (salen)Co–OTs. This reversible counterion addition results in stable partitioning between nucleophilic and Lewis acidic catalyst species, allowing highly efficient catalysis throughout the course of the HKR reaction.Chemistry and Chemical Biolog
Author Correction: Complete elimination of information leakage in continuous-variable quantum communication channels
In the original published version of the Article, the inline equation for the conditional covariance matrix γ A|B was listed as γ A|B = γ A − γ B,11 −1 C ΠC. This equation should be γ A|B = γ A − γ B,11 −1 σ AB Πσ AB . This has now been corrected in the PDF and HTML versions of the Article
Use of Fermented Red Clover Isoflavones in the Treatment of Overactive Bladder in Postmenopausal Women: A Randomized, Double-Blinded, Placebo-Controlled Trial
Postmenopausal women are at risk of developing an overactive bladder (OAB). Conventional vaginal estrogen has shown promise for symptom relief. Isoflavones have proven effective as an alternative to estrogen treatment against menopause-related symptoms. However, its effect on OAB symptoms has not been studied. This study investigates if fermented red clover isoflavones reduce OAB symptoms in postmenopausal women. In this randomized, double-blinded, placebo-controlled trial, women were administered red clover extract (RCE) or a placebo twice daily for three months. Women filled out the International Consultation on Incontinence Questionnaire Overactive Bladder (ICIQ-OAB) and Urinary Incontinence Short Form (ICIQ-UI-SF), together with a fluid intake and voiding diary. A total of 33 women (16 in the RCE group and 17 in the placebo group) were included in the analysis. Baseline demographics and OAB characteristics were comparable across groups. Intake of RCE did not lead to significant relief in most urinary bladder symptom measures, although a significant reduction in the bother of urinary urgency (p = 0.033) and a tendency towards a decreased ICIQ-OAB score were observed (p = 0.056). In contrast, the placebo exhibited a significant decrease in the ICIQ-OAB score (p = 0.021) and in some diary outcomes. We found that an intake of isoflavones did not relieve OAB symptoms in postmenopausal women.</p
Burn wounds infected with Pseudomonas aeruginosa triggers weight loss in rats
BACKGROUND: Despite dramatic improvements in the management of burns, infection still remains a serious risk for the burn patient. The aim of this study was to shed light on the impact of acute burn injury with or without infection on cytokine profiles. METHODS: Sprague-Dawley rats (n = 21) were randomized into three groups: 1) burn only 2) burn and infection or 3) sham burn. Weight was monitored and blood was collected for cytokine ELISA, LPS quantification, and peripheral blood analysis. Animals were sacrificed either after 6 or 12 days. RESULTS: Infected animals showed substantial weight loss until day 6 post-burn as compared to burn alone. Endotoxin and TNF-α levels were elevated early in the infected burn group within 48 hours post-burn. In contrast, significant up-regulation of the anti-inflammatory cytokine IL-10 occurred later in the clinical course and was associated with the recovery from weight loss. CONCLUSION: Our results suggest that in the presence of infection, you get a SIRS response possibly due to transient endotoxemia that is only seen in the infection group. In contrast, both burn and infection get a late IL-10 (CARS) response, which is then associated with a return to normal weight in the infection group
Ab initio van der Waals interactions in simulations of water alter structure from mainly tetrahedral to high-density-like
The structure of liquid water at ambient conditions is studied in ab initio
molecular dynamics simulations using van der Waals (vdW) density-functional
theory, i.e. using the new exchange-correlation functionals optPBE-vdW and
vdW-DF2. Inclusion of the more isotropic vdW interactions counteracts highly
directional hydrogen-bonds, which are enhanced by standard functionals. This
brings about a softening of the microscopic structure of water, as seen from
the broadening of angular distribution functions and, in particular, from the
much lower and broader first peak in the oxygen-oxygen pair-correlation
function (PCF), indicating loss of structure in the outer solvation shells. In
combination with softer non-local correlation terms, as in the new
parameterization of vdW-DF, inclusion of vdW interactions is shown to shift the
balance of resulting structures from open tetrahedral to more close-packed. The
resulting O-O PCF shows some resemblance with experiment for high-density water
(A. K. Soper and M. A. Ricci, Phys. Rev. Lett., 84:2881, 2000), but not
directly with experiment for ambient water. However, an O-O PCF consisting of a
linear combination of 70% from vdW-DF2 and 30% from experiment on low-density
liquid water reproduces near-quantitatively the experimental O-O PCF for
ambient water, indicating consistency with a two-liquid model with fluctuations
between high- and low-density regions
Loss of life years after a hip fracture: Effects of age and sex
Background Patients with a hip fracture have a high mortality; however, it is not clear how large the loss of life-years is over an extended observation period
Bacterial diversity in snow on North Pole ice floes
The microbial abundance and diversity in snow on ice floes at three sites near the North Pole was assessed using quantitative PCR and 454 pyrosequencing. Abundance of 16S rRNA genes in the samples ranged between 43 and 248 gene copies per millilitre of melted snow. A total of 291,331 sequences were obtained through 454 pyrosequencing of 16S rRNA genes, resulting in 984 OTUs at 97Â % identity. Two sites were dominated by Cyanobacteria (72 and 61Â %, respectively), including chloroplasts. The third site differed by consisting of 95Â % Proteobacteria. Principal component analysis showed that the three sites clustered together when compared to the underlying environments of sea ice and ocean water. The Shannon indices ranged from 2.226 to 3.758, and the Chao1 indices showed species richness between 293 and 353 for the three samples. The relatively low abundances and diversity found in the samples indicate a lower rate of microbial input to this snow habitat compared to snow in the proximity of terrestrial and anthropogenic sources of microorganisms. The differences in species composition and diversity between the sites show that apparently similar snow habitats contain a large variation in biodiversity, although the differences were smaller than the differences to the underlying environment. The results support the idea that a globally distributed community exists in snow and that the global snow community can in part be attributed to microbial input from the atmosphere. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00792-014-0660-y) contains supplementary material, which is available to authorized users
- …