gebhart/patrepeval huggingface dataset:
Safely enabling UAS operations in low-altitude airspace (2017)

NASA is developing a system to safely enable low altitude unmanned aerial system (UAS) operations. The system is referred to as UAS Traffic Management (UTM). The UTM will safely enable a variety of business models and multiple operations in the same airspace. The UTM will provide services such as airspace configuration and geo-fencing, weather and wind integration, demand-capacity imbalance management, and separation management, and contingency management. The UTM research and development has been conducted in collaboration with many in industry, academia, and government. The UTM system will evolve through four builds. Each build will be collaboratively tested with partners. The final prototype will be available for persistent daily use of UAS operations beyond line of sight.
Nonbinary LDPC-Coded Modulation for High-Speed Optical Fiber Communication Without Bandwidth Expansion (2012)

We propose a scheme that can attain the same transmission bit rate as the corresponding conventional polarization-division-multiplexed (PDM) quadrature amplitude modulation (QAM) scheme while occupying lower bandwidth and, hence, achieving a higher spectral efficiency. In contrast to the conventional approach, which increases the symbol rate and thus the occupied bandwidth to transmit the redundant symbols due to forward error correction (FEC), the proposed approach expands the underlying signal constellation in size and reduces the FEC code rate accordingly to form a mechanism that can achieve coded transmission without bandwidth expansion. Such a scheme can find applications in scenarios where there exist stringent bandwidth restrictions and bandwidth expansion is not considered as a viable option. Although the idea of constellation expansion in lieu of bandwidth expansion is mainly associated with Ungerboeck's trellis-coded modulation (TCM), our proposed nonbinary low-density parity-check (LDPC)-coded modulation scheme shows that block-coded modulation schemes can also be used with expanded constellations to achieve transmission without bandwidth expansion and without resorting to TCM. Our results reveal that for small to medium constellation sizes, the proposed scheme can preserve bandwidth while not experiencing significant increase in required optical signal-to-noise ratio (OSNR). For large constellation sizes, however, to keep the increase in required OSNR at manageable levels, we propose using controlled bandwidth expansion where constellation expansion and bandwidth expansion are used simultaneously to obtain a balance between the two critical system parameters of bandwidth and required OSNR.
Novel double-heterostructure lasers (1977)

In this paper we describe the preparation and characterization of two novel kinds of double-heterostructure (DH) lasers which combine both the Burrus LED and oxide-stripe laser technologies. Laser emission from one of the devices (Type I) emerges from a pair of holes which are etched through the substrate to expose the n-GaAlAs first confining layer. The n-GaAlAs/air interface forms the mirrors of the resonant optical cavity and the laser emission is perpendicular to the gain region, (active layer of the DH). In the second device (Type II) the resonant cavity is formed between the n-GaAlAs/air interface and a
SAMPL (2019)

Organized surveillance, especially by governments poses a major challenge to individual privacy, due to the resources governments have at their disposal, and the possibility of overreach. Given the impact of invasive monitoring, in most democratic countries, government surveillance is, in theory, monitored and subject to public oversight to guard against violations. In practice, there is a difficult fine balance between safeguarding individual's privacy rights and not diluting the efficacy of national security investigations, as exemplified by reports on government surveillance programs that have caused public controversy, and have been challenged by civil and privacy rights organizations. Surveillance is generally conducted through a mechanism where federal agencies obtain a warrant from a federal or state judge (e.g., the US FISA court, Supreme Court in Canada) to subpoena a company or service-provider (e.g., Google, Microsoft) for their customers' data. The courts provide annual statistics on the requests (accepted, rejected), while the companies provide annual transparency reports for public auditing. However, in practice, the statistical information provided by the courts and companies is at a very high level, generic, is released after-the-fact, and is inadequate for auditing the operations. Often this is attributed to the lack of scalable mechanisms for reporting and transparent auditing. In this paper, we present SAMPL, a novel auditing framework which leverages cryptographic mechanisms, such as zero knowledge proofs, Pedersen commitments, Merkle trees, and public ledgers to create a scalable mechanism for auditing electronic surveillance processes involving multiple actors. SAMPL is the first framework that can identify the actors (e.g., agencies and companies) that violate the purview of the court orders. We experimentally demonstrate the scalability for SAMPL for handling concurrent monitoring processes without undermining their secrecy and auditability.
Liposome-Encapsulated Actinomycin D: Potential in Cancer Chemotherapy (1974)

SummaryActinomycin D, when encapsulated within liposomes, is less toxic to mice than the nonencapsulated form. A single dose (0.75 mg/kg) or multiple doses (1 × 0.50, 4 × 0.25 mg/kg) significantly increased the mean survival time of mice inoculated with Ehrlich ascites tumor cells. Liposomes containing actinomycin D were found in tumor cells and cell degeneration and death were subsequently observed.
Design, Synthesis, and Biological Evaluation of a 1α,25-Dihydroxy-19-norvitamin D<sub>3</sub> Analogue with a Frozen A-Ring Conformation (2007)

To establish the conformation of vitamin D compounds responsible for biological activity, a 1alpha,25-dihydroxy-19-norvitamin D analogue 4 possessing a 1alpha-hydroxy group fixed in the axial orientation (beta-chair form) was synthesized. The starting compounds were bicyclic lactones 6, 7a, and 7b, derived from the quinic acid lactone, which were converted to the bicyclic ketone 13. Julia coupling of this compound with sulfone 15 produced the 19-norvitamin D analogue 4, possessing an additional ring connecting the 3beta-oxygen and C-2, and the isomeric 3beta-hydroxy compound 5. In vitro, both analogues 4 and 5 exhibit reduced activity compared to the natural hormone 1, but the binding, differentiation, and transcriptional activities of analogue 5 are markedly higher than that of 4 constrained in the alpha-chair conformation. Surprisingly, in vivo tests in mice showed that the analogue 4 significantly increases serum calcium at dose levels similar to 1alpha,25-(OH)2D3. These seemingly discordant results are discussed.
A New Family of Conotoxins That Blocks Voltage-gated Sodium Channels (1995)

Conus peptides, including omega-conotoxins and alpha-conotoxins (targeting calcium channels and nicotinic acetylcholine receptors, respectively) have been useful ligands in neuroscience. In this report, we describe a new family of sodium channel ligands, the mu-O-conotoxins. The two peptides characterized, mu-O-conotoxins MrVIA and MrVIB from Conus marmoreus potently block the sodium conductance in Aplysia neurons. This is in marked contrast to standard sodium channel blockers that are relatively ineffective in this system. The sequences of the peptides are as follows. mu-O-conotoxin MrVIA: ACRKKWEYCIVPIIGFIYCCPGLICGPFVCV mu-O-conotoxin MrVIB: ACSKKWEYCIVPILGFVYCCPGLICGPFVCV mu-O-conotoxin MrVIA was chemically synthesized and proved indistinguishable from the natural product. Surprisingly, the mu-O-conotoxins show no sequence similarity to the mu-O-conotoxins. However, ananalysis of cDNA clones encoding the mu-O-conotoxin MrVIB demonstrated striking sequence similarity to omega- and delta-conotoxin precursors. Together, the omega-, delta-, and mu-O-conotoxins define the O-superfamily of Conus peptides. The probable biological role and evolutionary affinities of these peptides are discussed.
Synthesis and Characterization of Site-Selective Ion-Exchange Resins Templated for Lead(II) Ion (1996)

Abstract Ion-exchange resins that exhibit enhanced selectivity for the Pb(II) ion have been synthesized by the copolymerization of styrene with lead(II) vinylbenzoate. Removal of the Pb(II) ion by acid washing left cavities templated for the Pb(II) ion. Sorption characteristics of the template resins have been studied over a large range of template loadings by varying the degrees of crosslinking, and with or without the use of ultrasonification during copolymerization. The capacity of the lead templated resins increases logarithmically with the increase of template complex content for levels of lead template content below 5 mol%. The complexation equilibrium constants of the resins reach a maximum at 3 mol% template complex content. The resins show marked preference for binding the Pb(II) ion. The selectivity,α pb,cd, has been found to be 174 for the 1 mol% templated polymer. In comparison to untemplated resins, the template process enhances the selectivity by roughly a factor of 3 over Cu2+ and 2 over Cd2+. The selectivity enhancement is mainly ascribed to “coordination-geometry selectivity.”
Simple and accurate wavemeter implemented with a polarization interferometer (1997)

A simple and accurate wavemeter for measuring the wavelength of monochromatic light is described. The device uses the wavelength-dependent phase lag between principal polarization states of a length of birefringent material (retarder) as the basis for the measurement of the optical wavelength. The retarder is sandwiched between a polarizer and a polarizing beam splitter and is oriented such that its principal axes are 45 deg to the axis of the polarizer and the principal axes of the beam splitter. As a result of the disparity in propagation velocities between the principal polarization states of the retarder, the ratio of the optical power exiting the two ports of the polarizing beam splitter is wavelength dependent. If the input wavelength is known to be within a specified range, the measurement of the power ratio uniquely determines the input wavelength. The device offers the advantage of trading wavelength coverage for increased resolution simply through the choice of the retarder length. Implementations of the device employing both bulk-optic components and fiber-optic components are described, and the results of a laboratory test of a fiber-optic prototype are presented. The prototype had a wavelength accuracy of +/-0.03 nm.
ChemInform Abstract: Chemistry of Tricarbonyl Hemiketals and Application of Evans′ Technology to the Total Synthesis of the Immunosuppressant (‐)‐FK‐506. (1990)

Abstract The title compound (XI), isolated from Streptomyces tsukubaensis, shows an immunosuppressive potency that is superior to that of cyclosporin A. Model reactions for the construction of the tricarbonyl region of (XI) are carried out and their use in designing a successful route to (XI) is shown in the scheme.
Recognition and penetration of the HIV-1 Env glycan shield by potent broadly neutralizing antibodies (2012)

Conclusion Structural characterization and biochemical analysis of these antibodies have uncovered novel specificities to new glycan-dependent epitopes and reveal further mechanisms for viral neutralization. These new epitopes provide additional insights for neutralization of HIV-1 and how antibodies can bind and penetrate the glycan shield, a novel framework for structure-assisted vaccine design. This study was supported by the International AIDS Vaccine Initiative (IAVI), Ragon Institute of MGH, MIT and Harvard, and NIH AI84817.
High Accuracy Monocular SFM and Scale Correction for Autonomous Driving (2015)

We present a real-time monocular visual odometry system that achieves high accuracy in real-world autonomous driving applications. First, we demonstrate robust monocular SFM that exploits multithreading to handle driving scenes with large motions and rapidly changing imagery. To correct for scale drift, we use known height of the camera from the ground plane. Our second contribution is a novel data-driven mechanism for cue combination that allows highly accurate ground plane estimation by adapting observation covariances of multiple cues, such as sparse feature matching and dense inter-frame stereo, based on their relative confidences inferred from visual data on a per-frame basis. Finally, we demonstrate extensive benchmark performance and comparisons on the challenging KITTI dataset, achieving accuracy comparable to stereo and exceeding prior monocular systems. Our SFM system is optimized to output pose within 50 ms in the worst case, while average case operation is over 30 fps. Our framework also significantly boosts the accuracy of applications like object localization that rely on the ground plane.
Compact Optical Atomic Clock Based on a Two-Photon Transition in Rubidium (2018)

Optical frequency standards surpass their microwave counterparts in both stability and accuracy, yet they are often bulky, power-hungry, and unable to operate outside of a well-controlled laboratory environment. Leveraging a two-photon transition in ${}^{87}$Rb vapor and recent advances in fiber frequency combs, the authors build an optical clock to beat the current portable standards, with an architecture that can be made compact and low-power. These results point the way to a real-world optical frequency standard of even higher stability, for applications such as satellite navigation.
Detection of SNP-Containing Human DNA Sequences Using a Split Sensor with a Universal Molecular Beacon Reporter (2013)

Hybridization-based techniques have been extensively employed for the analysis of specific DNA/RNA sequences. Herein, we describe highly specific inexpensive smart hybridization-based sensor that takes advantage of a universal molecular beacon probe as a fluorescent reporter. The sensor has a straightforward design, and demonstrates improved selectivity and specificity of nucleic acid recognition. It is cost-efficient since it utilizes the same molecular beacon probe for the analysis of many nucleic acid sequences.
Helicopter Anti-Torque System Using Strakes (1984)

A helicopter is disclosed with a system for controlling main-rotor torque which reduces the power and size requirements of conventional anti-torque means. The torque countering forces are generated by disrupting the main rotor downwash flowing around the fuselage. The downwash flow is separated from the fuselage surface by a strake positioned at a specified location on the fuselage. This location is determined by the particular helicopter wash pattern and fuselage configuration, generally being located between 20 deg before top dead center (TDC) and 80 deg from TDC on the fuselage side to which the main rotor blade approaches during rotation. The strake extends along the fuselage from the cabin section to the aft end and can be continuous or separated for aerodynamic surfaces such as a horizontal stabilizer.
Genetic algorithms : Are they the future of hearing aid fittings? The authors introduce and report preliminary research results on the genetic algorithm, a tool that may someday be used to provide a more efficient means to identify optimum hearing aid settings (2009)

The authors introduce and report preliminary research results on the genetic algorithm, a tool that may someday be used to provide a more efficient means to identify optimum hearing aid settings.
Forecasting Default in the Face of Uncertainty (2004)

Structural default models, starting with Merton, 1974, specify that default occurs when the value of the firm falls and hits a boundary that is a function of the firm9s debt liabilities. This means that default probability, and therefore the credit spread on the firm9s short-term debt, will be very close to zero when firm value is well above the barrier. But short-term spreads in the real world are not zero. In reduced-form models, default follows a random process that may hit at any time. This allows positive short-term spreads, but the cause of default is no longer modeled. In this article, Giesecke and Goldberg offer a hybrid approach, in which default occurs when firm value hits a barrier, but investors are uncertain about exactly where the barrier is. This is a very plausible assumption for real-world debt markets and it leads to a model with very plausible properties, including a connection between the value of the firm9s assets relative to its debt obligations, and positive credit spreads even at the shortest maturities. Examples drawn from recent experience of several firms illustrate the differences between their model and earlier structural approaches.
Purification of human leukotriene C<sub>4</sub> synthase from dimethylsulfoxide‐differentiated U937 cells (1992)

Human leukotriene C4 (LTC4) synthase was purified > 10000-fold from dimethylsulfoxide-differentiated U937 cells. Steps included: (a) solubilization of membrane-bound LTC4 synthase from microsomal membranes by the anionic detergent taurocholate; (b) successive anion-exchange chromatography steps in the presence of taurocholate plus Triton X-100 (primary anion exchange) then taurocholate plus n-octyl glucoside (secondary anion exchange); and (c) LTC2-affinity chromatography on a matrix that was constructed by first biotinylating synthetic LTC2 then immobilizing the biotinylated LTC2 on streptavidin agarose. The purification of human LTC4 synthase was enabled by the finding that LTC4 synthase activity in preparations enriched > 500-fold was absolutely dependent on the presence in LTC4 synthase incubation mixtures of divalent cations (specifically Mg2+) and phospholipids (specifically phosphatidylcholine), and that reduced glutathione, which was required at 2-4 mM for stabilization of LTC4 synthase, irreversibly inactivated the enzyme when present at > or = 5 mM during freeze/thaw cycles. The > 10000-fold purified LTC4 synthase preparation was comprised of three polypeptides having molecular masses of 37.1, 24.5 and 18.0 kDa. An 18-kDa polypeptide in both microsomal membranes and in the LTC2-affinity purified fraction was specifically labelled by a radioiodinated LTC4 photoaffinity probe (azido 125I-LTC4). The Km values in the LTC2-affinity purified preparation for reduced glutathione and LTA4 were 1.83 mM and 19.6 microM (respectively), closely resembling the Km values in isolated human blood monocytes. The Vmax of LTC2-affinity purified LTC4 synthase was 2-4 mumol LTC4 formed .min-1 x mg-1.
High detection efficiency ZnS scintillator for a fiber-coded linear neutron detector for thermal neutron scattering instruments (2008)

High detector efficiency ZnS/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> LiF scintillator and ZnS/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ceramic scintillator were developed for a fiber-coded linear neutron detector for thermal neutron detection. Detector performances of the detector equipped with such scintillator strips were evaluated in terms of neutron detector efficiency, gamma sensitivity, and quiet count rate. The detector equipped with the ZnS/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> LiF scintillator that contained twice amount of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> Li compared to the standard scintillator (ZnS/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> LiF scintillator produced by AST Co Ltd) exhibited about 30% higher detector efficiency for 1-Å neutrons. The fiber-coded detector equipped with the ZnS/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ceramic scintillator also exhibited about 30% larger neutron counts than the detector made with the standard scintillator. Moreover, the scintillation light of the ZnS/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ceramic scintillator exhibited 40% shorter decay time, indicating a potential for higher count rate capability.
PHOTODYNAMIC EFFECTS ON RETINAL OXYGEN SATURATION, BLOOD FLOW, AND ELECTROPHYSIOLOGICAL FUNCTION IN PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION (2009)

Oxygen saturation levels, mean blood flow, and mfERG amplitude decreased 1 week after PDT treatment in both single treatment and retreatment groups. Although logMAR vision is stable or improved, our data showed transient functional deterioration in the retina after PDT treatment.