4,708 research outputs found
Pitch-angle diffusion coefficients from resonant interactions with electrostatic electron cyclotron harmonic waves in planetary magnetospheres
Pitch-angle diffusion coefficients have been calculated for resonant
interaction with electrostatic electron cyclotron harmonic (ECH) waves in
the magnetospheres of Earth, Jupiter, Saturn, Uranus and Neptune.
Calculations have been performed at two radial distances of each planet. It
is found that observed wave electric field amplitudes in the magnetospheres
of Earth and Jupiter are sufficient to put electrons on strong diffusion in
the energy range of less than 100 eV. However, for Saturn, Uranus and
Neptune,
the observed ECH wave amplitude are insufficient to put electrons on strong
diffusion at any radial distance
Recent Techniques in Design and Implementation of Microwave Planar Filters
This paper details the techniques and initiatives made recently for improved response and simultaneous development of microwave planar filters. Although the objective of all the techniques is to design low cost filters with reduced dimensions, compact size with better frequency response, the methodological approaches are quite variant. The paper has gone through extensive analysis of all these techniques, their concept and design procedures
Modulation Method of Laser for Underwater Communication
Due to very high absorption of light in the water it is necessary to use high energy pulsed bluegreen lasers for underwater communication systems. However,these lasers do not have high repetition rates, sufficient enough to support high data rate signals. The pulse interval modulation method is one of the prospective methods of sending large bandwidth data using low frequency (500 to1000 pulses per second) pulsed laser. This method appears to be more promising for underwater communication system with likely development of fast PIM coder/decoder
Physical Acoustics
Contains research objectives and summary of research on three research projects.U. S. Navy - Office of Naval Research (Contract N00014-76-C-0090
Studies on the Thermodynamics of Exchange in Clays: Part II - Zinc Exchange on Na- & Ca-Illites
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Compact Broadband Monopole Antenna for C Band Applications
This paper reports a new design of broadband monopole patch antenna. The proposed antenna possess corner truncated rectangular patch with slits and defected ground structure, these modifications considerably improves the impedance bandwidth to 41.29% over a wideband (5.1–7.59 GHz). The design is appropriate for wireless communication including WLAN IEEE 802.11 g/a (5.15–5.35 GHz and 5.725–5.825 GHz) and C Band (4–8 GHz) applications. An antenna prototype is fabricated using FR-4 with an electrical permittivity of 4.4. Experimental and numerical simulations of antenna’s radiation characteristic are also reported and exhibits good concurrence
Tubular cell phenotype in HIV-associated nephropathy: Role of phospholipid lysophosphatidic acid
Collapsing glomerulopathy and microcysts are characteristic histological features of HIV-associated nephropathy (HIVAN). We have previously reported the role of epithelial mesenchymal transition (EMT) in the development of glomerular and tubular cell phenotypes in HIVAN. Since persistent tubular cell activation of NF kappa B has been reported in HIVAN, we now hypothesize that HIV may be contributing to tubular cell phenotype via lysophosphatidic acid (LPA) mediated downstream signaling. Interestingly, LPA and its receptors have also been implicated in the tubular interstitial cell fibrosis (TIF) and cyst formation in autosomal dominant polycystic kidney disease (PKD). Primary human proximal tubular cells (HRPTCs) were transduced with either empty vector (EV/HRPTCs), HIV (HIV/HRPTCs) or treated with LPA (LPA/HRPTC). Immunoelectrophoresis of HIV/HRPTCs and LPA/HRPTCs displayed enhanced expression of pro-fibrotic markers: a) fibronectin (2.25 fold), b) connective tissue growth factor (CTGF; 4.8 fold), c) alpha-smooth muscle actin (alpha-SMA; 12 fold), and d) collagen 1(5.7 fold). HIV enhanced tubular cell phosphorylation of ILK-1, FAK, PI3K, Akt, ERKs and P38 MAPK HIV increased tubular cell transcriptional binding activity of NF-kappa B; whereas, a LPA biosynthesis inhibitor (AACOCF3), a DAG kinase inhibitor, a LPA receptor blocker (Ki16425), a NF-kappa B inhibitor (PDTC) and NF kappa B-siRNA not only displayed downregulation of a NF kappa B activity but also showed attenuated expression of profibrotic/EMT genes in HIV milieu. These findings suggest that LPA could be contributing to HIV-induced tubular cell phenotype via NF kappa B activation in HIVAN. (C) 2015 Elsevier Inc. All rights reserved
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