Matroids and Quantum Secret Sharing Schemes

A secret sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum secret sharing schemes. In addition to providing a new perspective on quantum secret sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum secret sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum secret sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure state quantum secret sharing scheme with information rate one

Final Hazard Categorization for the Remediation of the 116-C-3 Chemical Waste Tanks

This final hazard categorization (FHC) document examines the hazards, identifies appropriate controls to manage the hazards, and documents the commitments for the 116-C-3 Chemical Waste Tanks Remediation Project. The remediation activities analyzed in this FHC are based on recommended treatment and disposal alternatives described in the Engineering Evaluation for the Remediation to the 116-C-3 Chemical Waste Tanks (BHI 2005e)

Economical (k,m)-threshold controlled quantum teleportation

We study a (k,m)-threshold controlling scheme for controlled quantum teleportation. A standard polynomial coding over GF(p) with prime p > m-1 needs to distribute a d-dimensional qudit with d >= p to each controller for this purpose. We propose a scheme using m qubits (two-dimensional qudits) for the controllers' portion, following a discussion on the benefit of a quantum control in comparison to a classical control of a quantum teleportation.Comment: 11 pages, 2 figures, v2: minor revision, discussions improved, an equation corrected in procedure (A) of section 4.3, v3: major revision, protocols extended, citations added, v4: minor grammatical revision, v5: minor revision, discussions extende

Symmetric multiparty-controlled teleportation of an arbitrary two-particle entanglement

We present a way for symmetric multiparty-controlled teleportation of an arbitrary two-particle entangled state based on Bell-basis measurements by using two Greenberger-Horne-Zeilinger states, i.e., a sender transmits an arbitrary two-particle entangled state to a distant receiver, an arbitrary one of the $n+1$ agents via the control of the others in a network. It will be shown that the outcomes in the cases that $n$ is odd or it is even are different in principle as the receiver has to perform a controlled-not operation on his particles for reconstructing the original arbitrary entangled state in addition to some local unitary operations in the former. Also we discuss the applications of this controlled teleporation for quantum secret sharing of classical and quantum information. As all the instances can be used to carry useful information, its efficiency for qubits approaches the maximal value.Comment: 9 pages, 3 figures; the revised version published in Physical Review A 72, 022338 (2005). The detail for setting up a GHZ-state quantum channel is adde

Stiff Mutant Genes of Phycomyces Affect Turgor Pressure and Wall Mechanical Properties to Regulate Elongation Growth Rate

Regulation of cell growth is paramount to all living organisms. In plants, algae and fungi, regulation of expansive growth of cells is required for development and morphogenesis. Also, many sensory responses of stage IVb sporangiophores of Phycomyces blakesleeanus are produced by regulating elongation growth rate (growth responses) and differential elongation growth rate (tropic responses). “Stiff” mutant sporangiophores exhibit diminished tropic responses and are found to be defective in at least five genes; madD, E, F, G, and J. Prior experimental research suggests that the defective genes affect growth regulation, but this was not verified. All the growth of the single-celled stalk of the stage IVb sporangiophore occurs in a short region termed the “growth zone.” Prior experimental and theoretical research indicates that elongation growth rate of the stage IVb sporangiophore can be regulated by controlling the cell wall mechanical properties within the growth zone and the magnitude of the turgor pressure. A quantitative biophysical model for elongation growth rate is required to elucidate the relationship between wall mechanical properties and turgor pressure during growth regulation. In this study, it is hypothesized that the mechanical properties of the wall within the growth zone of stiff mutant sporangiophores are different compared to wild type (WT). A biophysical equation for elongation growth rate is derived for fungal and plant cells with a growth zone. Two strains of stiff mutants are studied, C149 madD120 (−) and C216 geo- (−). Experimental results demonstrate that turgor pressure is larger but irreversible wall deformation rates within the growth zone and growth zone length are smaller for stiff mutant sporangiophores compared to WT. These findings can explain the diminished tropic responses of the stiff mutant sporangiophores. It is speculated that the defective genes affect the amount of wall-building material delivered to the inner cell wall

Rapid bursts of androgen-binding protein (Abp) gene duplication occurred independently in diverse mammals

<p>Abstract</p> <p>Background</p> <p>The draft mouse (<it>Mus musculus</it>) genome sequence revealed an unexpected proliferation of gene duplicates encoding a family of secretoglobin proteins including the androgen-binding protein (ABP) α, β and γ subunits. Further investigation of 14 α-like (<it>Abpa</it>) and 13 β- or γ-like (<it>Abpbg</it>) undisrupted gene sequences revealed a rich diversity of developmental stage-, sex- and tissue-specific expression. Despite these studies, our understanding of the evolution of this gene family remains incomplete. Questions arise from imperfections in the initial mouse genome assembly and a dearth of information about the gene family structure in other rodents and mammals.</p> <p>Results</p> <p>Here, we interrogate the latest 'finished' mouse (<it>Mus musculus</it>) genome sequence assembly to show that the <it>Abp </it>gene repertoire is, in fact, twice as large as reported previously, with 30 <it>Abpa </it>and 34 <it>Abpbg </it>genes and pseudogenes. All of these have arisen since the last common ancestor with rat (<it>Rattus norvegicus</it>). We then demonstrate, by sequencing homologs from species within the <it>Mus </it>genus, that this burst of gene duplication occurred very recently, within the past seven million years. Finally, we survey <it>Abp </it>orthologs in genomes from across the mammalian clade and show that bursts of <it>Abp </it>gene duplications are not specific to the murid rodents; they also occurred recently in the lagomorph (rabbit, <it>Oryctolagus cuniculus</it>) and ruminant (cattle, <it>Bos taurus</it>) lineages, although not in other mammalian taxa.</p> <p>Conclusion</p> <p>We conclude that <it>Abp </it>genes have undergone repeated bursts of gene duplication and adaptive sequence diversification driven by these genes' participation in chemosensation and/or sexual identification.</p

The effects of macroeconomic instability and inflation on sustainable real growth in South African firms

This empirical study is an investigation of the impact that inflation and other  factors have had on the growth of business firms in South Africa. Using the  model of sustainable growth, an empirical multivariate model is developed to  test a variety of assumed relationships and to isolate the impact of inflation. A  data set of South African firms’ financial statements during the period 1983-  1996 was assembled to permit a detailed examination of these firms’ financial  performance during South Africa’s period of isolation. Utilising both direct and  indirect measures of inflation, we determine that inflation affects growth in a  negative manner. By combing firm-level and macro data issues relating to the  endogeneity of inflation, we argue that macroeconomic instability is the true  factor adversely affecting firm growth during this period of time

Circular quantum secret sharing

A circular quantum secret sharing protocol is proposed, which is useful and efficient when one of the parties of secret sharing is remote to the others who are in adjacent, especially the parties are more than three. We describe the process of this protocol and discuss its security when the quantum information carrying is polarized single photons running circularly. It will be shown that entanglement is not necessary for quantum secret sharing. Moreover, the theoretic efficiency is improved to approach 100% as almost all the instances can be used for generating the private key, and each photon can carry one bit of information without quantum storage. It is straightforwardly to utilize this topological structure to complete quantum secret sharing with multi-level two-particle entanglement in high capacity securely.Comment: 7 pages, 2 figure