3,261 research outputs found
Golanudiplosis japonicus - a new midge attacking comstock mealybug in Japan (Diptera: Itonididae).
Die MĂŒcke, die in Japan die Eier der Mehlwanze Pseudococcus comstocki befĂ€llt, wird als neue Gattung Golanudiplosis mit der typischen Art japonicus beschrieben. Sowohl MĂ€nnchen wie Weibchen werden deskripiert, und ihre Stellung im System wird erörtert.Nomenklatorische Handlungenjaponicus Grover & Prasad, 1968 (Golanudiplosis), spec. n.Golanudiplosis Grover & Prasad, 1968 (Itonididae), gen. n.The midge found attacking eggs of the comstocki mealybug, Pseudococcus comstocki, in Japan is described as a new genus Golanudiplosis with japonicus as its type species. Both male and female are described in detail and their systematic position is discussed. Nomenclatural Actsjaponicus Grover & Prasad, 1968 (Golanudiplosis), spec. n.Golanudiplosis Grover & Prasad, 1968 (Itonididae), gen. n
High-pressure x-ray diffraction study of bulk and nanocrystalline PbMoO4
We studied the effects of high-pressure on the crystalline structure of bulk
and nanocrystalline scheelite-type PbMoO4. We found that in both cases the
compressibility of the materials is highly non-isotropic, being the c-axis the
most compressible one. We also observed that the volume compressibility of
nanocrystals becomes higher that the bulk one at 5 GPa. In addition, at 10.7(8)
GPa we observed the onset of an structural phase transition in bulk PbMoO4. The
high-pressure phase has a monoclinic structure similar to M-fergusonite. The
transition is reversible and not volume change is detected between the low- and
high-pressure phases. No additional structural changes or evidence of
decomposition are found up to 21.1 GPa. In contrast nanocrystalline PbMoO4
remains in the scheelite structure at least up to 16.1 GPa. Finally, the
equation of state for bulk and nanocrystalline PbMoO4 are also determined.Comment: 18 pages, 4 figure
Quantum Algorithm for Molecular Properties and Geometry Optimization
It is known that quantum computers, if available, would allow an exponential
decrease in the computational cost of quantum simulations. We extend this
result to show that the computation of molecular properties (energy
derivatives) could also be sped up using quantum computers. We provide a
quantum algorithm for the numerical evaluation of molecular properties, whose
time cost is a constant multiple of the time needed to compute the molecular
energy, regardless of the size of the system. Molecular properties computed
with the proposed approach could also be used for the optimization of molecular
geometries or other properties. For that purpose, we discuss the benefits of
quantum techniques for Newton's method and Householder methods. Finally, global
minima for the proposed optimizations can be found using the quantum basin
hopper algorithm, which offers an additional quadratic reduction in cost over
classical multi-start techniques.Comment: 6 page
Multilayer thin film encapsulation for organic light emitting diodes
A transparent and effective thin film encapsulation (TFE) based on a multilayer structure is demonstrated. Alternate films of amorphous and crystalline film forming organic materials have been investigated to create complicated diffusion pathways for oxygen and water vapour, which was reflected in their increased barrier properties. These layers are further protected by an inorganic barrier coating of magnesium fluoride (MgF2) deposited by normal and glancing angle deposition methods. A significant enhancement of more than 8 times in the lifetime of organic light emitting diodes was obtained by employing this multilayer hybrid geometry. The TFE structure can be highly useful in organic opto-electronic devices requiring easy to deposit and an effective barrier layer for enhanced lifetimes
Implementation of quantum search algorithm using classical Fourier optics
We report on an experiment on Grover's quantum search algorithm showing that
{\em classical waves} can search a -item database as efficiently as quantum
mechanics can. The transverse beam profile of a short laser pulse is processed
iteratively as the pulse bounces back and forth between two mirrors. We
directly observe the sought item being found in iterations, in
the form of a growing intensity peak on this profile. Although the lack of
quantum entanglement limits the {\em size} of our database, our results show
that entanglement is neither necessary for the algorithm itself, nor for its
efficiency.Comment: 4 pages, 3 figures; minor revisions plus extra referenc
Entangling capacity of global phases and implications for Deutsch-Jozsa algorithm
We investigate the creation of entanglement by the application of phases
whose value depends on the state of a collection of qubits. First we give the
necessary and sufficient conditions for a given set of phases to result in the
creation of entanglement in a state comprising of an arbitrary number of
qubits. Then we analyze the creation of entanglement between any two qubits in
three qubit pure and mixed states. We use our result to prove that entanglement
is necessary for Deutsch-Jozsa algorithm to have an exponential advantage over
its classical counterpart.Comment: All 8 figures at the en
Tissue factor expression, extracellular vesicles, and thrombosis after infection with the respiratory viruses influenza A virus and coronavirus
Tissue factor (TF) is induced in a variety of cell types during viral infection, which likely contributes to disseminated intravascular coagulation and thrombosis. TF-expressing cells also release TF-positive extracellular vesicles (EVs) into the circulation that can be measured using an EVTF activity assay. This review summarizes studies that analyze TF expression, TF-positive EVs, activation of coagulation, and thrombosis after infection with influenza A virus (IAV) and coronaviruses (CoVs), including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV, and Middle East respiratory syndrome CoV (MERS-CoV). The current pandemic of coronavirus disease 2019 (COVID-19) is caused by infection with SARS-CoV-2. Infection of mice with IAV increased TF expression in lung epithelial cells as well as increased EVTF activity and activation of coagulation in the bronchoalveolar lavage fluid (BALF). Infection of mice with MERS-CoV, SARS-CoV, and SARS-CoV-2 also increased lung TF expression. Single-cell RNA sequencing analysis on the BALF from severe COVID-19 patients revealed increased TF mRNA expression in epithelial cells. TF expression was observed in peripheral blood mononuclear cells infected with SARS-CoV. TF was also expressed by peripheral blood mononuclear cells, monocytes in platelet-monocyte aggregates, and neutrophils isolated from COVID-19 patients. Elevated circulating EVTF activity was observed in severe IAV and COVID-19 patients. Importantly, EVTF activity was associated with mortality in severe IAV patients and with plasma D-dimer, severity, thrombosis, and mortality in COVID-19 patients. These studies strongly suggest that increased TF expression in patients infected with IAV and pathogenic CoVs contributes to thrombosis
Statistical Constraints on State Preparation for a Quantum Computer
Quantum computing algorithms require that the quantum register be initially
present in a superposition state. To achieve this, we consider the practical
problem of creating a coherent superposition state of several qubits. Owing to
considerations of quantum statistics, this requires that the entropy of the
system go down. This, in turn, has two practical implications: (i) the initial
state cannot be controlled; (ii) the temperature of the system must be reduced.
These factors, in addition to decoherence and sensitivity to errors, must be
considered in the implementation of quantum computers.Comment: 7 pages; the final published versio
Geometric Strategy for the Optimal Quantum Search
We explore quantum search from the geometric viewpoint of a complex
projective space , a space of rays. First, we show that the optimal quantum
search can be geometrically identified with the shortest path along the
geodesic joining a target state, an element of the computational basis, and
such an initial state as overlaps equally, up to phases, with all the elements
of the computational basis. Second, we calculate the entanglement through the
algorithm for any number of qubits as the minimum Fubini-Study distance to
the submanifold formed by separable states in Segre embedding, and find that
entanglement is used almost maximally for large . The computational time
seems to be optimized by the dynamics as the geodesic, running across entangled
states away from the submanifold of separable states, rather than the amount of
entanglement itself.Comment: revtex, 10 pages, 7 eps figures, uses psfrag packag
Quantum heuristic algorithm for traveling salesman problem
We propose a quantum heuristic algorithm to solve a traveling salesman
problem by generalizing Grover search. Sufficient conditions are derived to
greatly enhance the probability of finding the tours with extremal costs,
reaching almost to unity and they are shown characterized by statistical
properties of tour costs. In particular for a Gaussian distribution of the
tours along the cost we show that the quantum algorithm exhibits the quadratic
speedup of its classical counterpart, similarly to Grover search.Comment: Published versio
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