Solid state image sensor research

Solid state image sensing devices developed for meteorological satellite application

Perampanel inhibition of AMPA receptor currents in cultured hippocampal neurons.

Perampanel is an aryl substituted 2-pyridone AMPA receptor antagonist that was recently approved as a treatment for epilepsy. The drug potently inhibits AMPA receptor responses but the mode of block has not been characterized. Here the action of perampanel on AMPA receptors was investigated by whole-cell voltage-clamp recording in cultured rat hippocampal neurons. Perampanel caused a slow (τ∼1 s at 3 µM), concentration-dependent inhibition of AMPA receptor currents evoked by AMPA and kainate. The rates of block and unblock of AMPA receptor currents were 1.5×105 M-1 s-1 and 0.58 s-1, respectively. Perampanel did not affect NMDA receptor currents. The extent of block of non-desensitizing kainate-evoked currents (IC50, 0.56 µM) was similar at all kainate concentrations (3-100 µM), demonstrating a noncompetitive blocking action. Parampanel did not alter the trajectory of AMPA evoked currents indicating that it does not influence AMPA receptor desensitization. Perampanel is a selective negative allosteric AMPA receptor antagonist of high-affinity and slow blocking kinetics

Four-Majorana qubit with charge readout: dynamics and decoherence

We present a theoretical analysis of a Majorana-based qubit consisting of two topological superconducting islands connected via a Josephson junction. The qubit is operated by electrostatic gates which control the coupling of two of the four Majorana zero modes. At the end of the operation, readout is performed in the charge basis. Even though the operations are not topologically protected, the proposed experiment can potentially shed light on the coherence of the parity degree of freedom in Majorana devices and serve as a first step towards topological Majorana qubits. We discuss in detail the charge-stability diagram and its use for characterizing the parameters of the devices, including the overlap of the Majorana edge states. We describe the multi-level spectral properties of the system and present a detailed study of its controlled coherent oscillations, as well as decoherence resulting from coupling to a non-Markovian environment. In particular, we study a gate-controlled protocol where conversion between Coulomb-blockade and transmon regimes generates coherent oscillations of the qubit state due to the overlap of Majorana modes. We show that, in addition to fluctuations of the Majorana coupling, considerable measurement errors may be accumulated during the conversion intervals when electrostatic fluctuations in the superconducting islands are present. These results are also relevant for several proposed implementations of topological qubits which rely on readout based on charge detection

On the reduction of the CSP dichotomy conjecture to digraphs

It is well known that the constraint satisfaction problem over general relational structures can be reduced in polynomial time to digraphs. We present a simple variant of such a reduction and use it to show that the algebraic dichotomy conjecture is equivalent to its restriction to digraphs and that the polynomial reduction can be made in logspace. We also show that our reduction preserves the bounded width property, i.e., solvability by local consistency methods. We discuss further algorithmic properties that are preserved and related open problems.Comment: 34 pages. Article is to appear in CP2013. This version includes two appendices with proofs of claims omitted from the main articl

Sub-nanometer free electrons with topological charge

The holographic mask technique is used to create freely moving electrons with quantized angular momentum. With electron optical elements they can be focused to vortices with diameters below the nanometer range. The understanding of these vortex beams is important for many applications. Here we present a theory of focused free electron vortices. The agreement with experimental data is excellent. As an immediate application, fundamental experimental parameters like spherical aberration and partial coherence are determined.Comment: 4 pages, 5 figure

On the homomorphism order of labeled posets

Partially ordered sets labeled with k labels (k-posets) and their homomorphisms are examined. We give a representation of directed graphs by k-posets; this provides a new proof of the universality of the homomorphism order of k-posets. This universal order is a distributive lattice. We investigate some other properties, namely the infinite distributivity, the computation of infinite suprema and infima, and the complexity of certain decision problems involving the homomorphism order of k-posets. Sublattices are also examined.Comment: 14 page

Pest and diseases of 16 local and exotic sweet-potato varieties in Benin and their agronomic characteristics.

Morphological characteristics and agronomic parameters were studied on 16 sweet-potato varieties (5 East Africa, 9 Benin, 1 China and 1 Bolivia) in April to August 2011 in southern Benin. Varietal variability was observed for length of internodes, leaf petiole, stem and leaf number. Positive significant correlations existed between stem length, number of leaves and number of tubers and tuber yield. In the same trial, incidence and severity of pests and diseases and effects on yield were observed. Six pests, Ptyelus sp., Aspidomorpha sp., B. tabaci, Blosyrus sp., C. puncticollis and P. grossipes and one disease, anthracnose were observed. The density of pests was low (less than 0,2 insect by plant on the average). Incidence of leaf-eating pests such as Ptyelus sp., Aspidomorpha sp., Blosyrus sp. reached 100% from the 7th week, while severity evolved linearly reaching over 50% for all varieties 17 weeks after planting. Anthracnose was identified at the end of the growing season on all exotic varieties and on some local varieties (Manouga, Fornonwinka and Gboadobodouaho). Anthracnose increased on 400166 (25%); 440029 (35%); Carrot-c (10%) and Manouga (9%). Yield was not affected by the pests and diseases. Damage from termites, C. puncticollis, rodents, nematodes and Alternaria sp. were observed on less than 15 tubers. Highest yield was observed for 440029, Vobodouaho, Kolidokpon and Manouga. There was no effect of pests on yield; we suggest that this study is repeated in all the agro-ecological zones of Béni