gebhart/patrepeval huggingface dataset:
Gamma‐vinyl GABA inhibits methamphetamine, heroin, or ethanol‐induced increases in nucleus accumbens dopamine (1999)

We examined the acute effect of the irreversible GABA-transaminase inhibitor, gamma-vinyl GABA (GVG, Sabril®, Vigabatrin®) on increases in nucleus accumbens (NAc) dopamine (DA) following acute administration of methamphetamine, heroin, or ethanol. Methamphetamine (2.5 mg/kg) produced a dose-dependent increase (2,700%) in NAc DA. GVG preadministration (300 or 600 mg/kg), however, inhibited this response by approximately 39 and 61%, respectively. The lower dose of methamphetamine (1.25 mg/kg), increased DA by 1,700%. This response was inhibited to a similar extent (44%) regardless of the GVG dose preadministered (300 or 600 mg/kg). In addition, heroin-induced increases in NAc DA (0.5 mg/kg, 170%) were inhibited or completely abolished by GVG (150 or 300 mg/kg, 65 and 100%, respectively). Finally, at half the dose necessary for heroin, GVG (150 mg/kg) also completely abolished ethanol-induced increases in NAc DA following a 0.25 g/kg challenge dose (140%). Taken with our previous findings using nicotine or cocaine as the challenge drug, these results indicate that GVG attenuates increases in NAc DA by a mechanism common to many drugs of abuse. However, it appears unlikely that an acute dose of GVG can completely inhibit increases in NAc DA following challenges with a drug whose mechanism of action is mediated primarily through the DA reuptake site. Synapse 34:11–19, 1999. © 1999 Wiley-Liss, Inc.
Power-factor-corrected single-stage inductive charger for electric-vehicle batteries (2002)

A novel power-factor-corrected single-stage AC-DC converter for inductive charging of electric vehicle batteries is introduced. The resonant converter uses the current-source characteristic of the series-parallel topology to provide power factor correction over a wide output power range from zero to full load. Some design guidelines for this converter are outlined. An approximate small-signal model of the converter is also presented Experimental results verify the operation of the new converter.
PN code chip time tracking with smart antennas (2002)

This paper proposes to employ a smart antenna to improve pseudonoise (PN) code chip time tracking loop (PNCTL), and analyzes its performance in the third generation (3G) wideband code division multiple access wireless communications channel (W-CDMA). Since a smart antenna can improve the signal-to-interference-plus-noise power ratio (SINR), the smart antenna may also improve the PNCTL performance as well as the bit error rate (BER) and capacity of the CDMA system. We consider the mean-time-to-lose-lock (MTLL) as the performance criteria. The PNCTL takes the smart antenna array output as its input. We examine both the first and second order PNCTLs, and employ a normalized least mean square (NLMS) algorithm to update the weight vector for the smart antenna. A flat Rayleigh Jakes fading multipath is taken as the channel model, and independent additive white Gaussian noise (AWGN) is added at each antenna element. Through both analysis and simulation, we demonstrate that the MTLL can be significantly improved under fading and AWGN environments, compared to a single antenna element, e.g., a 6 dB improvement in SINR with four antenna elements.
Temperature feedback control for long-term carrier-envelope phase locking (2009)

We report a double feedback loop for the improvement of the carrier-envelope phase stabilization of a chirped mirror based femtosecond laser oscillator. By combining the control of the Ti:sapphire crystal temperature and the modulation of the pump power, the carrier envelope offset frequency, fCEO, was locked for close to 20 h, which is much longer than the typical phase stabilization time with only pump power modulation.
Magnetic properties of (110) [001] oriented low alloy iron (1976)

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation D. R. Thornburg, K. Foster, G. C. Rauch; Magnetic properties of (110) [001] oriented low alloy iron. AIP Conf. Proc. 1 May 1976; 29 (1): 554–555. https://doi.org/10.1063/1.30446 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search
<title>Correlation-tracking strain estimator for elastography</title> (2002)

We describe a novel strain estimation method, which is capable of accurate strain estimation in the presence of large or irregular tissue motion. In conventional elastography, tissue strains induced by external compression applied to the tissue surface, are estimated by cross-correlation analysis of echo signals obtained before and after compression. Large and irregular tissue motions significantly change echo-signal shapes, causing major echo-signal decorrelations. In the presence of significant signal decorrelations, the estimated displacements may have many discontinuities because of false peak errors (primary correlation peak smaller than a secondary peak). However, because tissue is virtually incompressible, true elastographic displacements have spatial continuity in both axial and lateral directions, and the true correlation peaks, albeit diminished, are still present and detectable in the presence of spurious peaks. Our approach treats the total ensemble of correlation functions vs. depth and use information from neighboring areas to remove ambiguity that results from false peak errors. Preliminary results using finite-element simulation show that the correlation-tracking strain estimator (CTSE) can produce excellent strain estimates in harsh environments.
Detection near 1-nm with a laminar-flow, water-based condensation particle counter (2016)

Presented is a laminar-flow, water-based condensation particle counter capable of particle detection near 1 nm. This instrument employs a three-stage, laminar-flow growth tube with a “moderator” stage that reduces the temperature and water content of the output flow without reducing the peak supersaturation, and makes feasible operation at the large temperature differences necessary for achieving high supersaturations. The instrument has an aerosol flow of 0.3 L/min, and does not use a filtered sheath flow. It is referred to as a “versatile” water condensation particle counter, or vWCPC, as operating temperatures can be adjusted in accordance with the cut-point desired. When operated with wall temperatures of ∼2°C, >90°C, and ∼22°C for the three stages, respectively, the vWCPC detects particles generated from a heated nichrome wire with a 50% efficiency cut-point near 1.6 nm mobility diameter. At these operating temperatures, it also detects 10–20% of large molecular ions formed from passing filtered ambient air through a bipolar ion source. Decreasing the temperature difference between the first two stages, with the first and second stages operated at 10 and 90°C, respectively, essentially eliminates the response to charger ions, and raises the 50% efficiency cut-point for the nichrome wire particles to 1.9 nm mobility diameter. The time response, as measured by rapid removal of an inlet filter, yields a characteristic time constant of 195 ms.Copyright © 2017 American Association for Aerosol Research
Rational Design to Block Amino Acid Editing of a tRNA Synthetase (2002)

Investigations in chemical biology have focused on the synthesis of custom-designed proteins with site-specific incorporation of novel amino acids. Their success requires stable production of misacylated tRNAs. Utilization of aminoacyl-tRNA synthetases has been hindered because of enzyme molecular recognition mechanisms that ensure high fidelity of protein synthesis. Leucyl-tRNA synthetase naturally misaminoacylates chemically diverse standard and nonstandard amino acids, but contains a separate amino acid editing active site to hydrolyze incorrectly mischarged tRNAs. In this work, a rational mutagenesis design to block enzyme editing is described and involves substitution of bulky amino acids into the amino acid binding pocket of the hydrolytic active site. These engineered enzymes stably misacylated isoleucine to tRNALeu. The use of these mutant leucyl-tRNA synthetases has the potential to produce pools of mischarged tRNAs that are linked to nonstandard amino acids for in vitro translation. In addition, since many of the leucyl-tRNA synthetases do not interact with or rely upon the tRNA anticodon for identity, these enzymes may offer an excellent scaffold for the development of orthogonal tRNA synthetase/tRNA pairs that can potentially be used to customize protein synthesis.
Design and Evaluation of Organic Nonlinear Optical Materials with a Large Pockels Effect (1990)

Abstract This paper reviews a method of examining the Pockels effect in small and thin flakes of organic material, and discusses the possibility of further improving the Pockels effect in organic materials in terms of the molecular orbital method. The electro-optic coefficient r33 of the styrylpyridinium cyanine dye (SPCD) crystal was estimated from the AC modulation method to be about 430 pm/V at a wavelength λ of 633 nm, 6 times larger than the r11 of 2-methyl-4-nitroaniline (MNA). To improve the Pockels effect further, artificial molecules with a polydiacetylene structure were designed. By adjusting conjugated lengths and donor- and acceptor-substitution sites in the molecules, a large second-order hyperpolarizability was obtained, corresponding to an electro-optic coefficient about 10 times larger than r11 of MNA at a detuning energy of 0.2 eV.
Fast frequency-resolved terahertz imaging (2011)

We propose a fast, frequency-resolved, real-time, terahertz imaging method. With our method, images at two specific terahertz frequencies can be acquired in 1 min. Three kinds of drugs (L-histidine, maltose, and CBZ3), which have absorption peaks in the terahertz region, were distinguished in 3 min by using our method. This technique can be used in industrial applications, such as nondestructive testing.
High performance sensor fusion architecture for vision-based occupant detection (2004)

We describe a fast and reliable vision system for detecting and recognizing occupants in automobiles. The main advantage of our system is its high accuracy due to the use of fusion module, which combines the results of multiple classifiers operating on different types of features (edges, scale, and range) from the same image. Another advantage is that since the same image sensor is used to generate the multiple feature types, cost is reduced. We utilize an active illumination strategy to provide adequate illumination car seat and shadow fill-in during both the night and day. Occupant position detection and recognition is performed on the actively illuminated image using the same algorithm under both night and day conditions. Our system can use images from commercially available CMOS vision sensors and thus very cost-effective and efficient for smart air bag applications in automobiles. We have successfully demonstrated this system operating in a test vehicle at real-time video rates (30 updates/sec) with high accuracies for a large variety of situations and lighting conditions.
Least Squares Superposition Codes of Moderate Dictionary Size, Reliable at Rates up to Capacity (2010)

For the additive white Gaussian noise channel with average codeword power constraint, new coding methods are devised in which the codewords are sparse superpositions, that is, linear combinations of subsets of vectors from a given design, with the possible messages indexed by the choice of subset. Decoding is by least squares, tailored to the assumed form of linear combination. Communication is shown to be reliable with error probability exponentially small for all rates up to the Shannon capacity.
Merge Frame Design for Video Stream Switching Using Piecewise Constant Functions (2016)

The ability to efficiently switch from one pre-encoded video stream to another (e.g., for bitrate adaptation or view switching) is important for many interactive streaming applications. Recently, stream-switching mechanisms based on distributed source coding (DSC) have been proposed. In order to reduce the overall transmission rate, these approaches provide a merge mechanism, where information is sent to the decoder, such that the exact same frame can be reconstructed given that any one of a known set of side information (SI) frames is available at the decoder (e.g., each SI frame may correspond to a different stream from which we are switching). However, the use of bit-plane coding and channel coding in many DSC approaches leads to complex coding and decoding. In this paper, we propose an alternative approach for merging multiple SI frames, using a piecewise constant (PWC) function as the merge operator. In our approach, for each block to be reconstructed, a series of parameters of these PWC merge functions are transmitted in order to guarantee identical reconstruction given the known SI blocks. We consider two different scenarios. In the first case, a target frame is first given, and then merge parameters are chosen, so that this frame can be reconstructed exactly at the decoder. In contrast, in the second scenario, the reconstructed frame and the merge parameters are jointly optimized to meet a rate-distortion criteria. Experiments show that for both scenarios, our proposed merge techniques can outperform both a recent approach based on DSC and the SP-frame approach in H.264, in terms of compression efficiency and decoder complexity.
Photophysical Properties and Antibacterial Activity of Meso-substituted Cationic Porphyrins¶ (2002)

A series of derivatives of 5,10,15,20-tetrakis-(4-N-methylpyridyl)-porphine, where one N-methyl group was replaced by a hydrocarbon chain ranging from C6 to C22, were characterized for their photophysical and photosensitizing properties. The absorption and fluorescence features of the various compounds in neutral aqueous solutions were typical of largely monomeric porphyrins, with the exception of the C22 derivative, which appeared to be extensively aggregated. This was confirmed by the very low triplet quantum yield and lifetime of the C22 derivative as compared with 0.2-0.7 quantum yields and 88-167 micros lifetimes for the other porphyrins. The photophysical properties and photosensitizing activity toward N-acetyl-L-tryptophanamide of the C22 porphyrin became comparable to those typical of the other derivatives in 2% aqueous sodium dodecyl sulfate, where the C22 compound is fully monomerized. All the porphyrin derivatives exhibited at micromolar concentrations photoinactivation activity against both Staphylococcus aureus and Escherichia coli, even though the gram-negative bacteria were markedly less photosensitive. The photosensitizing efficiency was influenced by (1) the amount of cell-bound porphyrin, which increased with increasing length of the hydrocarbon chain; and (2) the tendency to undergo partial aggregation in the cell, which seems to be especially important for the C22 derivative.
Inducing Cross-Clade Neutralizing Antibodies against HIV-1 by Immunofocusing (2008)

This strategy, which was designed to focus the immune system on a few Env epitopes (immunofocusing), not only induced HIV-C gp160 binding antibodies and cross-clade nAbs, but also linked a conserved HIV Env region for the first time to the induction of nAbs: the C-terminus of gp120. The identification of conserved antigen mimics may lead to novel immunogens capable of inducing broadly reactive nAbs.
Photothermal multipixel imaging microscope (2004)

Photothermal microscopy is a useful nondestructive tool for the identification of fluence-limiting defects in optical coatings. Traditional photothermal microscopes are single-pixel detection devices. Samples are scanned under the microscope to generate a defect map. For high-resolution images, scan times can be quite long (1 mm<sup>2</sup> per hour). Single-pixel detection has geen used traditionally because of the ease in separating the laser-induced topographical change due to defect absorption from the defect surface topography. This is accomplished by using standard chopper and lock-in amplifier techniques to remove the DC signal. Multi-pixel photothermal microscopy is now possible by utilizing an optical lock-in technique. This eliminates the lock-in amplifier and enables the use of a CCD camera with an optical lock in for each pixel. With this technique, the data acquisition speed can be increased by orders of magnitude depending on laser power, beam size, and pixel density.
Implementation of a multilayer perceptron network using an optically addressed photoconductive array (2002)

A two-dimensional amorphous silicon photoconductor array and a liquid crystal display form the core components of a hardware system for implementation of a multilayer perceptron neural network. All connections between layers, as well as the nonlinear transfer characteristics associated with the hidden- and output-layer neurons, are implemented in analog circuitry so that the network, once trained, behaves as a stand-alone processor. The network is shown to train very successfully, using a standard backpropagation training algorithm, on the classification of handwritten digits. A computer simulation of the hardware network is described. Excellent agreement is shown between the results of the hardware network and those of the computer simulation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
<title>Design and analysis of a water window imaging x-ray microscope</title> (1991)

The authors have theoretically designed and analyzed the optical components and mechanical structures for an imaging x-ray microscope which will be configured to operate in the water window. This instrument affords new and noninvasive strategies for examining living tumor cells without the use of dyes, stains or other exogenous chemicals, which can produce limiting artifacts. The Water Window Imaging X-Ray Microscope is based on doubly reflecting, normal incidence multilayer optical technology, such as has been previously employed in telescopes for high resolution x-ray imaging of the sun. Multilayer coatings have now been fabricated with near theoretical reflectivities and perfect bandpass matching for the new rocket-borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). These telescopes employ multilayer mirror substrates with sub-angstrom (rms) smoothness which are made possible by Advanced Flow Polishing. Recent developments in multilayer coating technology and Advanced Flow Polishing methods used with Zerodur and Hemlite grade sapphire have paved the way for the development of the Water Window Imaging X-Ray Microscope. In this narrow water window wavelength regime of the x-ray spectrum, which lies between the K absorption edges of oxygen (23.3 $ANS) and of carbon (43.62 $ANS), water is relatively highly transmissive and carbon is highly absorptive. This principle allows the Water Window Imaging X-Ray Microscope to delineate, with high resolution and high contrast, carbon-based structures in the aqueous physiological environments found within living cells. The theoretical design and analysis of the microscope optical and mechanical components are described and the fabrication effort underway for the development of this new optical instrument, which should improve diagnosis and greatly benefit experimental studies of tumor cell biology, is discussed.
<title>Mean-preserving multilevel halftoning algorithm</title> (1993)

In multilevel halftoning, the appearance of intermediate shades of gray is created by the spatial modulation of more than two tones, i.e., black, white, and one or more gray tones. Periodic multilevel halftoning can be implemented similarly to bitonal halftoning by using N-1 identically sized threshold matrices for N available output levels. The amount of modulation in the output image is dependent on both the number of output levels and the spatial arrangement of threshold values. A method is presented for assessing the modulation resulting from a periodic multilevel halftone algorithm. The method is based on the constraint that the digital output of the halftone process be mean-preserving with respect to the input. This constraint is applied to the tone transfer functions of each pixel in the halftone cell, producing the result that the sum of the derivatives of all the unquantized tone transfer functions must equal the number of pixels in the halftone cell for all input values. This rule leads to a simple graphical technique for evaluating the modulation in a halftone algorithm as well as suggesting an infinite number of ways to vary the modulation. The application of this method to traditional as well as alternate halftone architectures is discussed.
Using graphics rendering contexts to enhance the real-time video coding for mobile cloud gaming (2011)

The emerging cloud gaming service has been growing rapidly, but not yet able to reach mobile customers due to many limitations, such as bandwidth and latency. We introduce a 3D image warping assisted real-time video coding method that can potentially meet all the requirements of mobile cloud gaming. The proposed video encoder selects a set of key frames in the video sequence, uses the 3D image warping algorithm to interpolate other non-key frames, and encodes the key frames and the residues frames with an H.264/AVC encoder. Our approach is novel in taking advantage of the run-time graphics rendering contexts (rendering viewpoint, pixel depth, camera motion, etc.) from the 3D game engine to enhance the performance of video encoding for the cloud gaming service. The experiments indicate that our proposed video encoder has the potential to beat the state-of-art x264 encoder in the scenario of real-time cloud gaming. For example, by implementing the proposed method in a 3D tank battle game, we experimentally show that more than 2 dB quality improvement is possible.
Nanosecond-Timescale Low Energy Switching of In-Plane Magnetic Tunnel Junctions through Dynamic Oersted-Field-Assisted Spin Hall Effect (2016)

We investigate fast-pulse switching of in-plane-magnetized magnetic tunnel junctions (MTJs) within 3-terminal devices in which spin-transfer torque is applied to the MTJ by the giant spin Hall effect. We measure reliable switching, with write error rates down to 10<sup>-5</sup>, using current pulses as short as just 2 ns in duration. This represents the fastest reliable switching reported to date for any spin-torque-driven magnetic memory geometry and corresponds to a characteristic time scale that is significantly shorter than predicted possible within a macrospin model for in-plane MTJs subject to thermal fluctuations at room temperature. Using micromagnetic simulations, we show that in the three-terminal spin-Hall devices the Oersted magnetic field generated by the pulse current strongly modifies the magnetic dynamics excited by the spin-Hall torque, enabling this unanticipated performance improvement. Our results suggest that in-plane MTJs controlled by Oersted-field-assisted spin-Hall torque are a promising candidate for both cache memory applications requiring high speed and for cryogenic memories requiring low write energies.