6,959 research outputs found

    Resource state structure for controlled quantum key distribution

    Full text link
    Quantum entanglement plays a pivotal role in many communication protocols, like secret sharing and quantum cryptography. We consider a scenario where more than two parties are involved in a protocol and share a multipartite entangled state. In particular, we considered the protocol of Controlled Quantum Key Distribution (CoQKD), introduced in the Ref. Chin. Phys. Lett. 20, 183-185 (2003), where, two parties, Alice and Bob establish a key with the cooperation of other parties. Other parties control/supervise whether Alice and Bob can establish the key, its security and key rate. We discuss the case of three parties in detail and find suitable resource states. We discuss the controlling power of the third party, Charlie. We also examine the usefulness of the new resource states for generating conference key and for cooperative teleportation. We find that recently introduced Bell inequalities can be useful to establish the security of the conference key. We also generalize the scenario to more than three parties.Comment: 11 pages, 7 figures. Close to published versio

    Herbal gardens of India: A statistical analysis report

    Get PDF
    A knowledge system of the herbal garden in India was developed and these herbal gardens’ information was statistically classified for efficient data processing, sharing and retrieving of information, which could act as a decision tool to the farmers, researchers, decision makers and policy makers in the field of medicinal plant species.Key words: Knowledge system, herbal garden, medicinal plant, decision tool

    A Protease Isolated from the Latex of Plumeria rubra Linn (Apocynaceae) 1: Purification and Characterization

    Get PDF
    Purpose: To isolate, purify and characterize protease from the latex of the plant.Methods: Protease was isolated from the latex of Plumeria rubra Linn using acetone precipitation method and purified by a sequence of DEAE cellulose column chromatography, followed by two successive column purification in Sephadex G-50 and Sephadex G-200. The molecular weight of the purified protease was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE). The protease was given a trivial name, Plumerin-R.Results: Plumerin-R showed a single protein band on SDS-PAGE and molecular weight was approximately 81.85 kDa. It remained active over a broad range of temperature but had optimum activity at 55 °C and pH 7.0 when casein was used as substrate. Activation of the protease by a thiol-activating agent indicated the presence of sulfhydryl as an essential group for its activity.Conclusion: A protease from the latex of Plumeria rubra Linn was purified to homogeneity by a simple purification procedure and then characterized.Keywords: Protease, Plumerin-R, Sulfhydryl, Purification; Characterizatio

    Nucleosynthesis in Advective Accretion Disks Around Galactic and Extra-Galactic Black Holes

    Get PDF
    We compute the nucleosynthesis of materials inside advective disks around black holes. We show that composition of incoming matter can change significantly depending on the accretion rate and accretion disks. These works are improvements on the earlier works in thick accretion disks of Chakrabarti, Jin & Arnett (1987) in presence of advection in the flow.Comment: Latex pages including figures. Kluwer Style files included. Appearing in `Observational Evidence for Black Holes in the Universe', ed. Sandip K. Chakrabarti, Kluwer Academic Publishers (DORDRECHT: Holland

    Approximation algorithm for finding multipacking on Cactus

    Full text link
    For a graph G=(V,E) G = (V, E) with vertex set V V and edge set E E , a function f:V→{0,1,2,...,diam(G)} f : V \rightarrow \{0, 1, 2, . . . , diam(G)\} is called a \emph{broadcast} on G G . For each vertex u∈V u \in V , if there exists a vertex v v in G G (possibly, u=v u = v ) such that f(v)>0 f (v) > 0 and d(u,v)≤f(v) d(u, v) \leq f (v) , then f f is called a \textit{dominating broadcast} on G G . The \textit{cost} of the dominating broadcast ff is the quantity ∑v∈Vf(v) \sum_{v\in V}f(v) . The minimum cost of a dominating broadcast is the \textit{broadcast domination number} of GG, denoted by γb(G) \gamma_{b}(G) . A \textit{multipacking} is a set S⊆V S \subseteq V in a graph G=(V,E) G = (V, E) such that for every vertex v∈V v \in V and for every integer r≥1 r \geq 1 , the ball of radius r r around v v contains at most r r vertices of S S , that is, there are at most r r vertices in S S at a distance at most r r from v v in G G . The \textit{multipacking number} of G G is the maximum cardinality of a multipacking of G G and is denoted by mp(G) mp(G) . We show that, for any cactus graph GG, γb(G)≤32mp(G)+112\gamma_b(G)\leq \frac{3}{2}mp(G)+\frac{11}{2}. We also show that γb(G)−mp(G)\gamma_b(G)-mp(G) can be arbitrarily large for cactus graphs by constructing an infinite family of cactus graphs such that the ratio γb(G)/mp(G)=4/3\gamma_b(G)/mp(G)=4/3, with mp(G)mp(G) arbitrarily large. This result shows that, for cactus graphs, we cannot improve the bound γb(G)≤32mp(G)+112\gamma_b(G)\leq \frac{3}{2}mp(G)+\frac{11}{2} to a bound in the form γb(G)≤c1⋅mp(G)+c2\gamma_b(G)\leq c_1\cdot mp(G)+c_2, for any constant c1<4/3c_1<4/3 and c2c_2. Moreover, we provide an O(n)O(n)-time algorithm to construct a multipacking of GG of size at least 23mp(G)−113 \frac{2}{3}mp(G)-\frac{11}{3} , where nn is the number of vertices of the graph GG

    The Subjective Response to Nitrous Oxide is a Potential Pharmaco-Endophenotype for Alcohol Use Disorder: A Preliminary Study with Heavy Drinkers.

    Get PDF
    BACKGROUND: Healthy people with a family history of alcohol problems show a pattern of subjective responses to alcohol that resemble those of affected probands. Studies on ketamine suggest that up-regulation of N-methyl-D-aspartate receptors (NMDARs) underlies these effects, and point to a pharmacologically-responsive endophenotype reflecting enhanced risk for alcohol-use disorders. METHODS: Subjective stimulant and sedative effects were assessed before and during nitrous oxide (N2O; 50%) inhalation in heavy drinkers who were otherwise healthy. RESULTS: Participants with an ostensible family history of alcohol-use disorders (n = 23) were distinguishable from those without such familial risk (n = 37) by an enhanced stimulation-to-sedation ratio during N2O inhalation. CONCLUSION: The pattern of subjective effects of N2O according to familial risk is remarkably similar to that previously seen with ketamine, supporting the idea of a common, NMDAR-mediated mechanism of action. N2O may prove to be a safe and accessible alternative to ketamine for probing heritable NMDAR dysregulation in neuropsychiatric disorders
    • …
    corecore