12,134 research outputs found
Orbifold cup products and ring structures on Hochschild cohomologies
In this paper we study the Hochschild cohomology ring of convolution algebras
associated to orbifolds, as well as their deformation quantizations. In the
first case the ring structure is given in terms of a wedge product on twisted
polyvectorfields on the inertia orbifold. After deformation quantization, the
ring structure defines a product on the cohomology of the inertia orbifold. We
study the relation between this product and an -equivariant version of the
Chen--Ruan product. In particular, we give a de Rham model for this equivariant
orbifold cohomology
High Input Impedance Voltage-Mode Universal Biquadratic Filters With Three Inputs Using Three CCs and Grounding Capacitors
Two current conveyors (CCs) based high input impedance voltage-mode universal biquadratic filters each with three input terminals and one output terminal are presented. The first circuit is composed of three differential voltage current conveyors (DVCCs), two grounded capacitors and four resistors. The second circuit is composed of two DVCCs, one differential difference current conveyor (DDCC), two grounded capacitors and four grounded resistors. The proposed circuits can realize all the standard filter functions, namely, lowpass, bandpass, highpass, notch and allpass filters by the selections of different input voltage terminals. The proposed circuits offer the features of high input impedance, using only grounded capacitors and low active and passive sensitivities. Moreover, the x ports of the DVCCs (or DDCC) in the proposed circuits are connected directly to resistors. This design offers the feature of a direct incorporation of the parasitic resistance at the x terminal of the DVCC (DDCC), Rx, as a part of the main resistance
THE 3-D KINEMATIC ANALYSIS OF DIFFERENT TENNIS SERVE
The key to success for a good tennis player is to be able to take the advantages of serving and keep the serve. The world's professional tennis players in front of the world rankings, most have very excellent serve skills. Two different footwork techniques in tennis serve used by most professional tennis players are the foot-up and foot-back serve technique. Most researchers investigated the differences between these footwork techniques using 2-D kinematics data (Elliott et al, 1983). However, little evidence has demonstrated that which serve technique is better (Bylak et al, 1998) or if a difference exists between foot-up and foot-back technique using 3-D analysis (Elliott et al, 1996). The purposes of this study were to investgate the differences in 3-D kinematics between the foot-up and foot-back tennis serve techniques
The System Si 3 N 4 -SiO 2 -Y 2 O 3
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65627/1/j.1151-2916.1980.tb10644.x.pd
A mutation in amino acid permease AAP6 reduces the amino acid content of the Arabidopsis sieve elements but leaves aphid herbivores unaffected
The aim of this study was to investigate the role of the amino acid permease gene AAP6 in regulating phloem amino acid composition and then to determine the effects of this altered diet on aphid performance. A genotype of Arabidopsis thaliana (L.) was produced in which the function of the amino acid permease gene AAP6 (At5g49630) was abolished. Plants homozygous for the insertionally inactivated AAP6 gene had a significantly larger mean rosette width than the wild type and a greater number of cauline leaves. Seeds from the aap6 mutant were also significantly larger than those from the wild-type plants. Sieve element (SE) sap was collected by aphid stylectomy and the amino acids derivatized, separated, and quantified using Capillary Electrophoresis with Laser Induced Fluorescence (CE-LIF). In spite of the large variation across samples, the total amino acid concentration of SE sap of the aap6 mutant plants was significantly lower than that of the wild-type plants. The concentrations of lysine, phenylalanine, leucine, and aspartic acid were all significantly lower in concentration in the aap6 mutant plants compared with wild-type plants. This is the first direct demonstration of a physiological role for an amino acid transporter in regulating SE composition in vivo. The amino acid availability in sieve element sap is thought to be the major limiting factor for aphid growth and reproduction. Despite the changes in their diet, the aphid Myzus persicae (Sulzer) displayed only small changes in feeding behaviour on mutant plants when measured using the Electronic Penetration Graph (EPG) technique. Salivation by the aphid into the SE (E1 phase) was increased on mutant plants but there was no significant effect on other feeding EPG behaviours, or in the rate of honeydew production. Consistent with the small effect on aphid feeding behaviour, there was only a small effect of reduced sieve element amino acid concentration on aphid reproduction. The data are discussed in relation to the regulation of phloem composition and the role of phloem amino acids in regulating aphid performance
The high-energy galactic tau neutrino flux and its atmospheric background
We compare the tau neutrino flux arising from the galaxy and the earth
atmosphere for . The intrinsic and oscillated
tau neutrino fluxes from both sources are considered. We find that, for GeV, the oscillated flux along the galactic plane dominates
over the maximal intrinsic atmospheric flux, i.e., the flux along
the horizontal direction. We also briefly comment on the prospects for
observing these high-energy tau neutrinos.Comment: 3 pages, 2 figures, talk presented in EPS03, Aachen, German
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