6,573 research outputs found

    Peculiar liquid-feeding and pathogen transmission behavior of Aedes togoi and comparison with Anopheles sinensis

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    Female mosquitoes transmit various diseases as vectors during liquid-feeding. Identifying the determinants of vector efficiency is a major scientific challenge in establishing strategies against these diseases. Infection rate and transmission efficiency are interconnected with the mosquito-induced liquid-feeding flow as main indexes of vector efficiency. However, the relationship between liquid-feeding characteristics and pathogen remains poorly understood. The liquid-feeding behavior of Aedes togoi and Anopheles sinensis was comparatively investigated in conjunction with vector efficiency via micro-particle image velocimetry. The flow rates and ratio of the ejection volume of Aedes togoi were markedly higher than those of Anophels sinensis. These differences would influence pathogen re-ingestion. Wall shear stresses of these mosquito species were also clearly discriminatory affecting the infective rates of vector-borne diseases. The variations in volume of two pump chambers and diameter of proboscis of these mosquito species were compared to determine the differences in the liquid-feeding process. Liquid-feeding characteristics influence vector efficiency; hence, this study can elucidate the vector efficiency of mosquitoes and the vector-pathogen interactions and contribute to the development of strategies against vector-borne diseases.112Ysciescopu

    Floating of the lobes of mosquito (Aedes togoi) larva for respiration

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    Mosquito (Aedes togoi) larva has to float its siphon on the water surface to breathe air. To elucidate the floating mechanism of the siphon, morphological structures, especially the flap-like lobes and spiracle of the siphon, were observed. Wettability and dynamic behavior of the lobes on the water surface were also experimentally examined. The lobes formed a hollow cone shape under water and expanded on the water surface. The spiracle was located at the base of the cone. The lobes exhibited hydrophobic wettability. During floating process, the lobes were spread into a triangular shape in apical view, and the spiracle was exposed to air. When they were submerged in water, the lobes were folded into a cone shape to seal the spiracle and protect it from water penetration. These dynamic processes occurred at the water surface. In this study, the floating mechanism of the lobes for respiration was described based on the cross-sectional morphology of the lobes with the pressure induced by surface tension and the hydrostatic pressure proportional to depth. This study would be helpful in elucidating the behavior of mosquito larvae near the water surface and may facilitate the formulation of methods to control mosquito larvae.1122Ysciescopu

    Discrete Multitone Modulation for Maximizing Transmission Rate in Step-Index Plastic Optical Fibres

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    The use of standard 1-mm core-diameter step-index plastic optical fiber (SI-POF) has so far been mainly limited to distances of up to 100 m and bit-rates in the order of 100 Mbit/s. By use of digital signal processing, transmission performance of such optical links can be improved. Among the different technical solutions proposed, a promising one is based on the use of discrete multitone (DMT) modulation, directly applied to intensity-modulated, direct detection (IM/DD) SI-POF links. This paper presents an overview of DMT over SI-POF and demonstrates how DMT can be used to improve transmission rate in such IM/DD systems. The achievable capacity of an SI-POF channel is first analyzed theoretically and then validated by experimental results. Additionally, first experimental demonstrations of a real-time DMT over SI-POF system are presented and discusse

    Spin symmetry breaking in bilayer quantum Hall systems

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    Based on the construction of generalized Halperin wave functions, we predict the possible existence of a large class of broken spin symmetry states in bilayer quantum Hall structures, generalizing the recently suggested canted antiferromgnetic phase to many fractional fillings. We develop the appropriate Chern-Simons theory, and establish explicitly that the low-lying neutral excitation is a Goldstone mode and that the charged excitations are bimerons with continuously tunable (through the canted antiferromagnetic order parameter) electric charge on the individual merons.Comment: 4 page

    Kaon mass in dense matter

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    The variation of kaon mass in dense, charge-neutral baryonic matter at beta-equilibrium has been investigated. The baryon interaction has been included by means of nonlinear Walecka model, with and without hyperons and the interaction of kaons with the baryons has been incorporated through the Nelson-Kaplan model. A self-consistant, one-loop level calculation has been carried out. We find that at the mean field level, the presence of the hyperons makes the density-dependence of the kaon mass softer. Thus, the kaon condensation threshold is pushed up in the baryon density. The loop diagrams tend to lower the kaon condensation point for lower values of a3msa_3 m_s. We also find that the S-wave kaon-nucleon interaction plays the dominant role in determining the on-set of kaon condensation and the contribution of the P-wave interaction is insignificant.Comment: Four figures available on reques

    Spintronic properties of one-dimensional electron gas in graphene armchair ribbons

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    We have investigated, using effective mass approach (EMA), magnetic properties of a one-dimensional electron gas in graphene armchair ribbons when the electrons of occupy only the lowest conduction subband. We find that magnetic properties of the one-dimensional electron gas may depend sensitively on the width of the ribbon. For ribbon widths Lx=3Ma0L_x=3Ma_0, a critical point separates ferromagnetic and paramagnetic states while for Lx=(3M+1)a0L_x=(3M+1)a_0 paramagnetic state is stable (MM is an integer and a0a_{0} is the length of the unit cell). These width-dependent properties are a consequence of eigenstates that have a subtle width-dependent mixture of K\mathbf{K} and K\mathbf{K'} states, and can be understood by examining the wavefunction overlap that appears in the expression for the many-body exchange self-energy. Ferromagnetic and paramagnetic states may be used for spintronic purposes.Comment: 5 pages, 6 figure

    Parity Problem With A Cellular Automaton Solution

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    The parity of a bit string of length NN is a global quantity that can be efficiently compute using a global counter in O(N){O} (N) time. But is it possible to find the parity using cellular automata with a set of local rule tables without using any global counter? Here, we report a way to solve this problem using a number of r=1r=1 binary, uniform, parallel and deterministic cellular automata applied in succession for a total of O(N2){O} (N^2) time.Comment: Revtex, 4 pages, final version accepted by Phys.Rev.

    Current and charge distributions of the fractional quantum Hall liquids with edges

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    An effective Chern-Simons theory for the quantum Hall states with edges is studied by treating the edge and bulk properties in a unified fashion. An exact steady-state solution is obtained for a half-plane geometry using the Wiener-Hopf method. For a Hall bar with finite width, it is proved that the charge and current distributions do not have a diverging singularity. It is shown that there exists only a single mode even for the hierarchical states, and the mode is not localized exponentially near the edges. Thus this result differs from the edge picture in which electrons are treated as strictly one dimensional chiral Luttinger liquids.Comment: 21 pages, REV TeX fil
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