105 research outputs found
Quantum error correction via robust probe modes
We propose a new scheme for quantum error correction using robust continuous
variable probe modes, rather than fragile ancilla qubits, to detect errors
without destroying data qubits. The use of such probe modes reduces the
required number of expensive qubits in error correction and allows efficient
encoding, error detection and error correction. Moreover, the elimination of
the need for direct qubit interactions significantly simplifies the
construction of quantum circuits. We will illustrate how the approach
implements three existing quantum error correcting codes: the 3-qubit bit-flip
(phase-flip) code, the Shor code, and an erasure code.Comment: 5 pages, 3 figure
OVICIDAL EFFECT OF PIPERACEAE SPECIES ON Biomphalaria glabrata, Schistosoma mansoni HOST
SUMMARY Schistosomiasis is a neglected disease with public health importance in tropical and subtropical regions. An alternative to the disease control is the use of molluscicides to eliminate or reduce the intermediate host snail population causing a reduction of transmission in endemic regions. In this study nine extracts from eight Piperaceae species were evaluated against Biomphalaria glabrata embryos at blastula stage. The extracts were evaluated in concentrations ranging from 100 to 10 mg/L. Piper crassinervium and Piper tuberculatum extracts were the most active (100% of mortality at 20 mg/L and 30 mg/L respectively).RESUMO A esquistossomose é uma doença negligenciada de importância para a saúde pública em regiões tropicais e subtropicais. Uma alternativa para o controle da doença é o uso de moluscicidas para eliminar ou reduzir a população de caramujo hospedeiro, acarretando uma redução da transmissão da doença nas regiões endemicas. Neste estudo, nove extratos vegetais provenientes de oito espécies de Piperaceae foram expostos a embriões de Biomphalaria glabrata no estágio de blástula. Os extratos foram avaliados em concentrações que variaram entre 100 e 10 mg/L, sendo Piper crassinervium e Piper tuberculatum os extratos mais ativos (100% de mortalidade a 20 mg/L e 30 mg/L respectivamente)
Two chitinase-like proteins abundantly accumulated in latex of mulberry show insecticidal activity
<p>Abstract</p> <p>Background</p> <p>Plant latex is the cytoplasm of highly specialized cells known as laticifers, and is thought to have a critical role in defense against herbivorous insects. Proteins abundantly accumulated in latex might therefore be involved in the defense system.</p> <p>Results</p> <p>We purified latex abundant protein a and b (LA-a and LA-b) from mulberry (<it>Morus </it>sp.) and analyzed their properties. LA-a and LA-b have molecular masses of approximately 50 and 46 kDa, respectively, and are abundant in the soluble fraction of latex. Western blotting analysis suggested that they share sequence similarity with each other. The sequences of LA-a and LA-b, as determined by Edman degradation, showed chitin-binding domains of plant chitinases at the N termini. These proteins showed small but significant chitinase and chitosanase activities. Lectin RCA120 indicated that, unlike common plant chitinases, LA-a and LA-b are glycosylated. LA-a and LA-b showed insecticidal activities when fed to larvae of the model insect <it>Drosophila melanogaster</it>.</p> <p>Conclusions</p> <p>Our results suggest that the two LA proteins have a crucial role in defense against herbivorous insects, possibly by hydrolyzing their chitin.</p
Efficiency of free energy calculations of spin lattices by spectral quantum algorithms
Quantum algorithms are well-suited to calculate estimates of the energy
spectra for spin lattice systems. These algorithms are based on the efficient
calculation of the discrete Fourier components of the density of states. The
efficiency of these algorithms in calculating the free energy per spin of
general spin lattices to bounded error is examined. We find that the number of
Fourier components required to bound the error in the free energy due to the
broadening of the density of states scales polynomially with the number of
spins in the lattice. However, the precision with which the Fourier components
must be calculated is found to be an exponential function of the system size.Comment: 9 pages, 4 figures; corrected typographical and minor mathematical
error
Interaction Gardens and Butterfly Catalogues: a Joint Strategy to Promote Capacity Development in Protected Areas and Reduce the Extinction of Experience in Cities
More than half of the world’s population live in cities. Increasing numbers of generations are now born and raised in urban landscapes with decreasing opportunities towards interacting with natural environments. This extinction of experience leads to environmental apathy and lack of bioliteracy, which is a central aspect to be tackled in conservation strategies. At the same time, people who live near or at non-urban settings are closer to natural habitats but do not have similar access to concepts of environmentalism and may lack incentives to lean towards nature conservation, instead of its exploitation or even illegal activities. We here propose that interaction gardens, that is, gardens with multiple trophic levels (primary producers, herbivores, predators, and parasitoids), can tackle these issues, especially if planned with incentives, such as butterfly catalogues, aimed as a common goal of the garden community. It can also bring benefits to human health and well-being, increase the survival chances of local biodiversity, and strengthen the front line of conservation by promoting income strategies to people who live near protected areas. Our specific aims are to 1) share a case study of capacity development at the Intervales State Park in the Atlantic Forest, Southeast Brazil; 2) present the butterfly catalogue of this protected area; 3) present guidelines for interaction gardens at both urban and non-urban settings; and 4) discuss alternative perspectives about Neotropical conservation. We provide a translated version of the text in Portuguese to encourage students, educators, NGOs and local communities of other protected areas to venture in our proposed joint strategy of interaction gardens with butterfly catalogues
Efficient implementation of selective recoupling in heteronuclear spin systems using Hadamard matrices
We present an efficient scheme which couples any designated pair of spins in
heteronuclear spin systems. The scheme is based on the existence of Hadamard
matrices. For a system of spins with pairwise coupling, the scheme
concatenates intervals of system evolution and uses at most pulses
where . Our results demonstrate that, in many systems, selective
recoupling is possible with linear overhead, contrary to common speculation
that exponential effort is always required.Comment: 7 pages, 4 figures, mypsfig2, revtex, submitted April 27, 199
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