The extended metamorphosis of a complete bipartite design into a cycle system

A K-t,K-t-design of order n is an edge-disjoint decomposition of K-n into copies of K-t,K-t. When t is odd, an extended metamorphosis of a K-t,K-t-design of order n into a 2t-cycle system of order n is obtained by taking (t - 1)/2 edge-disjoint cycles of length 2t from each K-t,K-t block, and rearranging all the remaining 1-factors in each K-t,K-t block into further 2t-cycles. The 'extended' refers to the fact that as many subgraphs isomorphic to a 2t-cycle as possible are removed from each K-t,K-t block, rather than merely one subgraph. In this paper an extended metamorphosis of a K-t,K-t-design of order congruent to 1 (mod 4t(2)) into a 2t-cycle system of the same order is given for all odd t > 3. A metamorphosis of a 2-fold K-t,K-t-design of any order congruent to 1 (mod 4t(2)) into a 2t-cycle system of the same order is also given, for all odd t > 3. (The case t = 3 appeared in Ars Combin. 64 (2002) 65-80.) When t is even, the graph K-t,K-t is easily seen to contain t/2 edge-disjoint cycles of length 2t, and so the metamorphosis in that case is straightforward. (C) 2004 Elsevier B.V. All rights reserved.

Components of optical qubits encoded in sideband modes

We describe a scheme for the encoding and manipulation of single photon qubits in optical sideband modes using standard optical elements. We propose and analyze the radio frequency half-wave plate, which may be used to make arbitrary rotations of a state in the frequency basis, and the frequency beamsplitter, which may be used to separate (or combine) photons of different frequencies into (from) different spatial modes.

Transmission of optical coherent-state qubits

We discuss the long-distance transmission of qubits encoded in optical coherent states. Through absorption, these qubits suffer from two main types of errors, namely the reduction of the amplitude of the coherent states and accidental application of the Pauli Z operator. We show how these errors can be fixed using techniques of teleportation and error-correcting codes.

High-fidelity Z-measurement error encoding of optical qubits

We demonstrate a quantum error correction scheme that protects against accidental measurement, using a parity encoding where the logical state of a single qubit is encoded into two physical qubits using a nondeterministic photonic controlled-NOT gate. For the single qubit input states vertical bar 0 >, vertical bar 1 >, vertical bar 0 > +/- vertical bar 1 >, and vertical bar 0 > +/- i vertical bar 1 > our encoder produces the appropriate two-qubit encoded state with an average fidelity of 0.88 +/- 0.03 and the single qubit decoded states have an average fidelity of 0.93 +/- 0.05 with the original state. We are able to decode the two-qubit state (up to a bit flip) by performing a measurement on one of the qubits in the logical basis; we find that the 64 one-qubit decoded states arising from 16 real and imaginary single-qubit superposition inputs have an average fidelity of 0.96 +/- 0.03.

Multiquantum eigenstates of a linear chain of coupled qubits

We present a technique to identify exact analytic expressions for the multiquantum eigenstates of a linear chain of coupled qubits. A choice of Hilbert subspaces is described that allows an exact solution of the stationary Schrodinger equation without imposing periodic boundary conditions and without neglecting end effects, fully including the dipole-dipole nearest-neighbor interaction between the atoms. The treatment is valid for an arbitrary coherent excitation in the atomic system, any number of atoms, any size of the chain relative to the resonant wavelength and arbitrary initial conditions of the atomic system. The procedure we develop is general enough to be adopted for the study of excitation in an arbitrary array of atoms including spin chains and one-dimensional Bose-Einstein condensates.

Loss-tolerant optical qubits

We present a linear optics quantum computation scheme that employs a new encoding approach that incrementally adds qubits and is tolerant to photon loss errors. The scheme employs a circuit model but uses techniques from cluster-state computation and achieves comparable resource usage. To illustrate our techniques we describe a quantum memory which is fault tolerant to photon loss.

Interconvertibility of single-rail optical qubits

We show how to convert between partially coherent superpositions of a single photon with the vacuum by using linear optics and postselection based on homodyne measurements. We introduce a generalized quantum efficiency for such states and show that any conversion that decreases this quantity is possible. We also prove that our scheme is optimal by showing that no linear optical scheme with generalized conditional measurements, and with one single-rail qubit input, can improve the generalized efficiency. (c) 2006 Optical Society of America.

An Algorithm for Optimal Bipartite PLA Folding

This paper presents some results of PLA area optimizing by means of its column and row folding. A more restricted type of PLA simple folding is considered. It is introduced by Egan and Liu and called as bipartite folding. An efficient approach is presented which allows finding an optimal bipartite folding without exhaustive computational efforts.

Bipartite Assertion: A New Account of Assertion, Defined in Terms of Responsibility and Explicit Presentation

Assertion is a speech act that stands at the intersection of the philosophy of language and social epistemology. It is a phenomenon that bears on such wide-ranging topics as testimony, truth, meaning, knowledge and trust. It is thus no surprise that analytic philosophers have devoted innumerable pages to assertion, trying to give the norms that govern it, its role in the transmission of knowledge, and most importantly, what assertion is, or how assertion is to be defined. In this thesis I attempt to show that all previous answers to the question “What is assertion?” are flawed. There are four major traditions in the literature: constitutive norm theories of assertion, accounts that treat assertion as the expression of speaker attitudes, accounts that treat assertion as a proposal to add some proposition to the common ground, and accounts that treat assertion as the taking of responsibility for some claim. Each tradition is explored here, the leading theories within the tradition developed, and then placed under scrutiny to demonstrate flaws within the positions surveyed. I follow the work of G.E. Moore and William P. Alston, whilst drawing on the work of Robert Brandom in order to give a new bipartite theory of assertion. I argue that assertion consists in the explicit presentation of a proposition, along with a taking of responsibility for that proposition. Taking Alston's explicit presentation condition and repairing it in order to deal with problems it faces, whilst combining it with Brandom's responsibility condition, provides, I believe, the best account of assertion.

Influence of the bipartite scrotum on the testicular and scrotal temperatures in goats

O objetivo deste trabalho foi avaliar a influência do grau de bipartição escrotal e do período do ano sobre a termorregulação escroto-testicular em caprinos criados no Estado do Piauí. Foram utilizados 18 reprodutores caprinos machos, divididos em três grupos de seis animais: O Grupo I contendo caprinos com escroto simples, o Grupo II, caprinos com escroto bipartido até 50% do comprimento testicular e o Grupo III, caprinos com bipartição superior a 50% do comprimento testicular. Os parâmetros avaliados foram as temperaturas do escroto, testículo e funículo espermático, obtidas de forma invasiva, com um termômetro digital termoacoplável, e não invasiva, com um pirômetro, nos terços proximal, médio e distal. Os dados foram coletados nos períodos seco (outubro-novembro) e chuvoso (fevereiro-março) do ano, bem como, nos turnos da manhã (6h00 às 7h00) e tarde (14h00 às 15h00). Os resultados foram submetidos à análise de variância (ANOVA) seguida do teste SNK para comparação das médias (p<0,05). O período do ano interferiu na termorregulação escroto-testicular, pois no período seco as temperaturas do escroto, testículo e funículo espermático foram mais elevadas que as observadas no período chuvoso. O grau de bipartição do escroto foi outro fator que modificou a temperatura escroto-testicular, já que os caprinos que apresentaram escroto com maior grau de bipartição demonstraram as menores médias das temperaturas escroto-testiculares em ambos os períodos e turnos avaliados. Conclui-se, portanto, que tanto o período do ano quanto o grau de bipartição do escroto influenciaram o processo de termorregulação escroto-testicular em caprinos.

Smallest disentangling state spaces for general entangled bipartite quantum states

Entangled quantum states can be given a separable decomposition if we relax the restriction that the local operators be quantum states. Motivated by the construction of classical simulations and local hidden variable models, we construct `smallest' local sets of operators that achieve this. In other words, given an arbitrary bipartite quantum state we construct convex sets of local operators that allow for a separable decomposition, but that cannot be made smaller while continuing to do so. We then consider two further variants of the problem where the local state spaces are required to contain the local quantum states, and obtain solutions for a variety of cases including a region of pure states around the maximally entangled state. The methods involve calculating certain forms of cross norm. Two of the variants of the problem have a strong relationship to theorems on ensemble decompositions of positive operators, and our results thereby give those theorems an added interpretation. The results generalise those obtained in our previous work on this topic [New J. Phys. 17, 093047 (2015)].

Circuit Quantum Electrodynamics with Transmon Qubits in the Ultrastrong Coupling Regime

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Whitefly Transmission and Efficient ssDNA Accumulation of Bean Golden Mosaic Geminivirus Require Functional Coat Protein

Bean golden mosaic geminivirus (BGMV) has a bipartite genome composed of two circular ssDNA components (DNA-A and DNA-B) and is transmitted by the whitefly, Bemisia tabaci. DNA-A encodes the viral replication proteins and the coat protein. To determine the role of BGMV coat protein systemic infection and whitefly transmission, two deletions and a restriction fragment inversion were introduced into the BGMV coat protein gene. All three coat protein mutants produced systemic infections when coinoculated with DNA-B onto Phaseolus vulgaris using electric discharge particle acceleration "particle gun." However, they were not sap transmissible and coat protein was not detected in mutant-infected plants. In addition, none of the mutants were transmitted by whiteflies. With all three mutants, ssDNA accumulation of DNA-A and DNA-B was reduced 25- to 50-fold and 3- to 10-fold, respectively, as compared to that of wild-type DNA. No effect on dsDNA-A accumulation was detected and there was 2- to 5-fold increase in dsDNA-B accumulation. Recombinants between the mutated DNA-A and DNA-B forms were identified when the inoculated coat protein mutant was linearized in the common region.

Diversity of dicotyledenous-infecting geminiviruses and their associated DNA molecules in Southern Africa, including the South-west Indian Ocean Islands

The family Geminiviridae comprises a group of plant-infecting circular ssDNA viruses that severely constrain agricultural production throughout the temperate regions of the world, and are a particularly serious threat to food security in sub-Saharan Africa. While geminiviruses exhibit considerable diversity in terms of their nucleotide sequences, genome structures, host ranges and insect vectors, the best characterised and economically most important of these viruses are those in the genus Begomovirus. Whereas begomoviruses are generally considered to be either monopartite (one ssDNA component) or bipartite (two circular ssDNA components called DNA-A and DNA-B), many apparently monopartite begomoviruses are associated with additional subviral ssDNA satellite components, called alpha- (DNA-αs) or betasatellites (DNA-βs). Additionally, subgenomic molecules, also known as defective interfering (DIs) DNAs that are usually derived from the parent helper virus through deletions of parts of its genome, are also associated with bipartite and monopartite begomoviruses. The past three decades have witnessed the emergence and diversification of various new begomoviral species and associated DI DNAs, in southern Africa, East Africa, and proximal Indian Ocean islands, which today threaten important vegetable and commercial crops such as, tobacco, cassava, tomato, sweet potato, and beans. This review aims to describe what is known about these viruses and their impacts on sustainable production in this sensitive region of the world. © 2012 by the authors licensee MDPI, Basel, Switzerland.