gebhart/patrepeval huggingface dataset:
The Infidelity of Avian Myeloblastosis Virus Deoxyribonucleic Acid Polymerase in Polynucleotide Replication (1974)

Abstract We have studied the accuracy of DNA synthesis in vitro by purified avian myeloblastosis virus (AMV) DNA polymerase (reverse transcriptase) using synthetic polynucleotide templates. The enzyme catalyzes the incorporation of an exceptionally large number of incorrectly paired bases when copying ribopolynucleotide and deoxyribopolynucleotide templates. The frequency of error is approximately 1 in 600 when copying homopolymer templates and 1 in 6000 when copying alternating copolymer templates. The product of the reaction, using a template of polyriboadenylic acid of 2500 nucleotides long hybridized to an initiator of oligodeoxythymidylate of 12 to 18 nucleotides long was analyzed by velocity sedimentation and equilibrium density gradient centrifugation. The results indicate that: (a) the entire length of the given template is copied; (b) the incorrectly base-paired nucleotides are an integral part of the polynucleotide product; and (c) these errors are randomly distributed. Polyacrylamide gel electrophoretic analysis of the purified polymerase showed two subunits, α and β. The incorporation of the correct and incorrect nucleotides catalyzed by the active α subunit appears to be not influenced by the inactive β subunit. The purified polymerase has no detectable exoor endodeoxyribonuclease activity. AMV DNA polymerase exhibits identical requirements for the incorporation of the correct and incorrect nucleotides. The error rate is not a function of the number of initiator termini, Mg2+ concentration, time of incubation, or the amount of enzyme. The error rate is, however, dependent on the type of the template and on the ratio of correct to incorrect nucleotides in the reaction mixture. If this DNA polymerase from avian myeloblastosis virus makes similar errors in vivo this enzyme may be mutagenic.
Journalism and constructive learning: Trusting the good sense of our students (1996)

Constructive learning is described by some scholars as active, cumulative, goal-directed, diagnostic and reflective behaviour. This article claims that all of these behaviours are present in current journalistic education. Because there is little place in journalism practice for the learner who indulges in surface (rote) strategies, which are chosen to pass a test in many different disciplines, the journalism curriculum is unique in a sense that it rests on best pedagogical practice. These ideas are put in a philosophical context of teaching journalism as a liberal art. The introduction of the internet and online investigations are discussed as significant enhancements for the profession of journalism education.
Carrier lifetime in InP/InGaAs/InP by open-circuit voltage and photoluminescence decay (1995)

Carrier lifetime in n-InP/n-InGaAs/n-InP and Zn-diffused p-InP/p-n InGaAs/n-InP double heterostructures (DH) with undoped n-InGaAs was measured using the small signal open-circuit voltage and photoluminescence decay techniques. The structures were grown by the metalorganic chemical-vapor-deposition growth technique. The theoretical considerations required to correctly apply both techniques to structures containing a p-n junction are discussed in detail. Carrier lifetimes between 3 and 5 μs and between 8 and 15 μs were obtained for the p-InP/p-n InGaAs/n-InP and n-InP/n-InGaAs/n-InP DH, respectively. The carrier lifetimes measured in n-InP/n-InGaAs/n-InP confirm the long lifetimes previously deduced indirectly from continuous-wave and pulsed-optical-beam-induced current measurement techniques. The much shorter lifetimes measured in the Zn-diffused DH are basically due to a joint recombination process involving processes on both sides of the p-n junction structure. The analysis of the results show the possible reduction of bulk lifetime due to Zn-induced nonradiative recombination processes in the highly doped Zn-diffused region.
Molecular mechanisms of thrombosis. Fundamental and applied aspects of the contact activation (2014)

The human hemostatic system stops bleeding when vascular lesions occur. This is one of the most vulnerable physiological systems. Hemostatic disorders, which are encountered in patients with various diseases (i.e., atherosclerosis, trauma, sepsis, and cancer), may lead to both hemorrhage and thrombosis. Pathological clot formation is dangerous, and thrombosis is the most common cause of death in developed countries. Activated factor XII (fXIIa), a key enzyme of the contact pathway of coagulation, does not play a significant role in maintaining hemostasis but is involved in the pathological blood clotting. Therefore, this enzyme is a promising target for the development of antithrombotic drugs. Inhibition of the contact pathway is essential for any ex vivo manipulation involving blood (i.e., transfusion, cardiopulmonary bypass, and blood sampling) and when blood is exposed to foreign surfaces. In this review we consider modern views on the contact activation and the pathophysiological role of this process in the blood coagulation and other systems of the organism. Existing inhibitors of the contact pathway exhibit two mechanisms of action: a competitive binding to the active site of fXIIa and an allosteric inhibition via the N-terminal regulatory domain, which blocks activation by anionic surfaces and binding to physiological substrates. These two mechanisms are discussed. A comparison of existing inhibitors, with special emphasis on the most promising ones, and the criteria for new fXIIa inhibitors are also provided.
Biometric Methods for Secure Communications in Body Sensor Networks: Resource-Efficient Key Management and Signal-Level Data Scrambling (2007)

As electronic communications become more prevalent, mobile and universal, the threats of data compromises also accordingly loom larger. In the context of a body sensor network (BSN), which permits pervasive monitoring of potentially sensitive medical data, security and privacy concerns are particularly important. It is a challenge to implement traditional security infrastructures in these types of lightweight networks since they are by design limited in both computational and communication resources. A key enabling technology for secure communications in BSN's has emerged to be biometrics. In this work, we present two complementary approaches which exploit physiological signals to address security issues: (1) a resource-efficient key management system for generating and distributing cryptographic keys to constituent sensors in a BSN; (2) a novel data scrambling method, based on interpolation and random sampling, that is envisioned as a potential alternative to conventional symmetric encryption algorithms for certain types of data. The former targets the resource constraints in BSN's, while the latter addresses the fuzzy variability of biometric signals, which has largely precluded the direct application of conventional encryption. Using electrocardiogram (ECG) signals as biometrics, the resulting computer simulations demonstrate the feasibility and efficacy of these methods for delivering secure communications in BSN's.
Oxygen-Generating Nanofiber Cell Scaffolds with Antimicrobial Properties (2010)

Many next-generation biomaterials will need the ability to not only promote healthy tissue integration but to simultaneously resist bacterial colonization and resulting biomaterials-associated infection. For this purpose, antimicrobial nanofibers of polycaprolactone (PCL) were fabricated by incorporating calcium peroxide. PCL nanofibers containing different ratios of calcium peroxide (1%, 5% and 10% (w/w)) with or without ascorbic acid were fabricated using an electrospinning technique. Antimicrobial evaluations confirmed the inhibitory properties of the nanofibers on the growth of E. coli and S. epidemidis because of a significant burst release of calcium peroxide from the nanofibers. Analysis of tissue cell response showed that despite an initial toxic effect over the first 24 h, after 4 days of culture, osteoblast viability and morphology were both healthy. These results demonstrate that oxygen-generating nanofibers can be designed and developed to provide a short-term peroxide-based antimicrobial response while still maintaining attractive tissue-integration properties.
Optimization of breakdown voltage and on-resistance of VDMOS transistors (1984)

The combined effect of the spacing between adjacent drain junctions, epilayer thickness, and resistivity in VDMOS transistors on both its breakdown voltage and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R_{on} \cdot A</tex> product is investigated. It is shown that an increase in the breakdown voltage results as the junctions spacing is reduced. That gives a significant difference in the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R_{on} \cdot A</tex> product when compared with results where this effect is ignored. A design optimization study is carried out to determine the parameters of a VDMOS transistor at 1000-V breakdown.
Successful treatment of psoriasis vulgaris with targeted narrow‐band ultraviolet B therapy using a new flat‐type fluorescent lamp (2011)

Narrow-band ultraviolet B (NB-UVB) therapy is widely used for refractory skin diseases. Targeted phototherapy is now being used to reduce the number of sessions and to avoid exposing normal skin. We developed a targeted NB-UVB therapy using a flat-type lamp emitting a wavelength similar to that of the TL-01 fluorescent lamp. Six Japanese patients with psoriasis were recruited and treated with the flat-type NB-UVB device with an initial dose of 70% of the minimal erythema dose, with a 20% increase at each subsequent session. The plaque severity score was determined. All lesions of the tested patients were responsive to NB-UVB therapy using the flat-type lamp. The mean percent reduction of the lesion was 58.3 ± 17.7%. The mean cumulative dose was 20.8 ± 10.8 J/cm². No side effects were observed during treatment. The flat-type targeted NB-UVB device is compact and convenient, and highly effective for the treatment of limited psoriasis lesions.
A carrier and timing recovery technique for QAM transmission on digital subscriber loops (2002)

The asymmetric digital subscriber line (ADSL) service attempts to provide 1.6 Mb/s data transmission over a single twisted-pair copper loop for distances up to 18 kft. A simple timing and carrier recovery scheme for a quadrature amplitude modulation (QAM) approach is proposed. The algorithm uses the receiver decisions to eliminate the effects of intersymbol interference (ISI) as well as to provide estimates for samples of the pulse response at the demodulator output. These estimates are then used to generate a sampling phase error signal that can be used in a single phase locked loop configuration to correct carrier frequency, as well as timing offsets in the QAM based system. The algorithm exploits the characteristics of both the system as well as the environment, and is simple enough to allow integration with all other receiver blocks on a single integrated circuit. Preliminary results for an ADSL system with blind equalization starting from an unequalized state are presented. The new scheme is shown to be effective at acquiring and tracking frequency offsets as high as 112 ppm, without significantly degrading system performance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
End-to-End Deep Learning for Person Search. (2016)

Existing person re-identification (re-id) benchmarks and algorithms mainly focus on matching cropped pedestrian images between queries and candidates. However, it is different from real-world scenarios where the annotations of pedestrian bounding boxes are unavailable and the target person needs to be found from whole images. To close the gap, we investigate how to localize and match query persons from the scene images without relying on the annotations of candidate boxes. Instead of breaking it down into two separate tasks—pedestrian detection and person re-id, we propose an end-to-end deep learning framework to jointly handle both tasks. A random sampling softmax loss is proposed to effectively train the model under the supervision of sparse and unbalanced labels. On the other hand, existing benchmarks are small in scale and the samples are collected from a few fixed camera views with low scene diversities. To address this issue, we collect a largescale and scene-diversified person search dataset, which contains 18,184 images, 8,432 persons, and 99,809 annotated bounding boxes1. We evaluate our approach and other baselines on the proposed dataset, and study the influence of various factors. Experiments show that our method achieves the best result.
Small-signal modeling for design of robust variable-frequency flyback battery chargers for portable device applications (2002)

A novel methodology to derive small-signal models for a peak-current controlled variable-frequency flyback converter operating in boundary mode is presented. The loop gain of a universal input 5-W battery charger for mobile phones is analyzed and compared to the predictions. The results obtained show a good correlation between predictions and measurements validating the modeling. The implications (i.e. RHP and ESR zeros as well as opto-coupler in the feedback loop) for controller design is discussed.
Thermo-Optic Effects in Congruent-<i>LiTaO</i> <sub>3</sub> Based Continuous-Wave Optical Parametric Oscillator (2021)

We present an experimental study on single-frequency, singly-resonant optical parametric oscillator (SRO) comprised of 50 mm long congruently-grown, 8-mol%-doped, periodically-poled LiTaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (MgO:cPPLT) crystal. The SRO is pumped by a single-frequency, fiber laser pumped green laser. Our observations reveal that the SRO output (idler) scales linearly with the pump power ( P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</sub> ) near the SRO threshold ( P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p(th)</sub> ). However, the SRO idler power ( P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> ) exhibits strong saturation at pump power ≈ 1.5P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p(th)</sub> which eventually switches-off the SRO operation on further pump-power enhancement. By coarsely tuning the MgO:cPPLT crystal temperature from 50 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> C to 170 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> C, the SRO idler wavelength is varied from 1810-1920 nm wavelength band. A maximum idler power P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> =583 mW was obtained when the input pump power was ≈ 3.1 W. The idler power saturation is accompanied by discernible distortion in idler beam profile. An early onset of saturation in MgO:cPPLT is essentially a consequence of strong linear absorption exhibited by MgO:cPPLT at pump wavelength, its high thermo-optic coefficient as well as low thermal conductivity. The results are theoretically analyzed by solving the heat conduction equation which provides a deeper insight about the impact of pump-induced thermo-optic effects on a three-wave interaction process.
Structural Basis for the Catalytic Mechanism of a Proficient Enzyme:  Orotidine 5‘-Monophosphate Decarboxylase<sup>,</sup> (2000)

Orotidine 5'-monophosphate decarboxylase (ODCase) catalyzes the decarboxylation of orotidine 5'-monophosphate, the last step in the de novo synthesis of uridine 5'-monophosphate. ODCase is a very proficient enzyme [Radzicka, A., and Wolfenden, R. (1995) Science 267, 90-93], enhancing the reaction rate by a factor of 10(17). This proficiency has been enigmatic, since it is achieved without metal ions or cofactors. Here we present a 2.5 A resolution structure of ODCase complexed with the inhibitor 1-(5'-phospho-beta-D-ribofuranosyl)barbituric acid. It shows a closely packed dimer composed of two alpha/beta-barrels with two shared active sites. The orientation of the orotate moiety of the substrate is unambiguously deduced from the structure, and previously proposed catalytic mechanisms involving protonation of O2 or O4 can be ruled out. The proximity of the OMP carboxylate group with Asp71 appears to be instrumental for the decarboxylation of OMP, either through charge repulsion or through the formation of a very short O.H.O hydrogen bond between the two carboxylate groups.
Monolithic microwave gallium arsenide FET oscillators (1981)

Results of the first monolithic microwave GaAs FET oscillator [1] are presented. The oscillator design philosophy is outlined. Design procedures for the oscillator and techniques for realization of various circuit components on the semi-insulating GaAs substrate are indicated. Performance of the oscillator is described and commented upon.
Cyclization reactions in the chemical ionization spectra of bifunctional alkyl phenyl ethers (1979)

Abstract Evidence is presented for the formation of cyclic onium ions from bifunctional alkyl phenyl ethers under chemical ionization conditions.
High-Density Monomer System for Formation Consolidation/Water Shutoff Applications (1999)

Abstract This paper describes a monomer system for formation consolidation in deepwater applications. In deepwater wells, shallow zones may have pore pressures close to fracturing pressures. In these situations, lost circulation or flowing zones can be difficult to control and can lead to a complete loss of the well. Hydroperoxide and azo initiators were used for polymerizing solutions of 2-hydroxyethyl acrylate in aqueous solutions of sea salt, sodium chloride (NaCl), calcium chloride (CaCl2), calcium bromide (CaBr2), and zinc bromide (ZnBr2) with densities from 8.6 to 17.5 lbm/gal. These monomer solutions undergo controlled polymerizations in the formation to yield stiff plugs that can withstand high differential pressures. A similar monomer system has been used for water shutoff applications, but had never been formulated in heavy brines or used in the cool temperatures (50° to 60°F) typical of the shallow water-flow zones. Using a high-density consolidation fluid would be advantageous in shallow water-flow zones. This fluid could be spotted over the problem zone and allowed to flow into the zone because of the hydrostatic pressure. This fluid would allow the treatments to be used in wells where high-pressure injection into the formation is not an option. Before this work, no high-density fluids were available for these applications. Various data are shown describing the system's development, including gel-time curves and compressive strengths of consolidated sandpacks. Factors affecting the performance and application of the system are discussed.
Inhibition of Carbon Steel Corrosion in Chemical Cleaning Solutions Containing Solid Magnetites (1983)

A solvent composed of 8% EDTA, 2% citric acid, and 0.5% hydrazine, used at pH 6, and which was developed for the chemical cleaning of nuclear steam generators, was studied at 95 C for its agressiveness against carbon steel. Corrosion protection is improved by adding sulfur-free organic inhibitors to the pure solvent. In spite of this, when simulating the presence of corrosion products by adding magnetite, the effect of such inhibitors, as well as the corrosivity of the pure solvent, may be radically affected. Furthermore, different supplies of magnetite, whether they are added to the pure or the inhibited solvent, may have different solubilities and can drastically affect the corrosion rates. This might be explained in terms of the hydrazine evolution and/or the effective hydrazine content in solution during the test. It is found, nevertheless, that synergistic effects between surfactants and inhibitors could inhibit carbon steel corrosion, regardless of the supply of magnetite used. A mixture of benzotriazole, Triton X-100, and Chevron NI-W has been found useful as an inhibitor to chemical cleaning solvents of the type considered.
Evaluation of adenosine 5'-monophosphate and fluoride as adenylate kinase inhibitors in the creatine kinase assay. (1976)

Adenylate kinase (EC 2.7.4.3) interferes positively in the serum creatine kinase (EC 2.7.3.2) assay when the rate of ATP production is monitored by a coupled enzyme system. A dual assay, measuring creatine kinase and adenylate kinase activity, was used to evaluate AMP and other possible adenylate kinase inhibitors that would permit specific measurement of creatine kinase activity in the presence of adenylate kinase. We found that AMP, routinely included in the creatine kinase assay system to inhibit adenylate kinase, partially inhibits both human serum creatine kinase and purified creatine kinase from rabbit muscle. The amount of creatine kinase inhibition is related directly to the AMP concentration and inversely to the substrate (ADP) concentration. We found that 25 mmol/liter of fluoride inhibits adenylate kinase without measurable effect on creatine kinase activity. We developed a serum creatine kinase assay including fluoride, and compared it with the dual assay system and with two commercial assay kits. Other halides or adenosine 2'-monophosphate did not selectively inhibit adenylate kinase.
LabelMe video: Building a video database with human annotations (2009)

Currently, video analysis algorithms suffer from lack of information regarding the objects present, their interactions, as well as from missing comprehensive annotated video databases for benchmarking. We designed an online and openly accessible video annotation system that allows anyone with a browser and internet access to efficiently annotate object category, shape, motion, and activity information in real-world videos. The annotations are also complemented with knowledge from static image databases to infer occlusion and depth information. Using this system, we have built a scalable video database composed of diverse video samples and paired with human-guided annotations. We complement this paper demonstrating potential uses of this database by studying motion statistics as well as cause-effect motion relationships between objects.