gebhart/patrepeval huggingface dataset:
Migrating state information in mobile environments (2002)

Several studies point out the deficiencies of the transport protocol TCP in wireless scenarios. Falsely, TCP's congestion avoidance mechanisms are triggered by packets that are destroyed due to the high bit error probability of wireless channels or loss due to disruptions caused by handoffs. This can be avoided, if the indirect transport protocol model approach is applied. It subdivides the end-to-end transport connection into two connections, one operating over the wired subpath, the other over the wireless subpath. A so called transport gateway is used to interconnect both transport connections. If the geographical distance between the transport gateway and the mobile station increases, the active transport layer entities should be migrated to another transport gateway closer to the mobile host. Depending on the amount of transferred state information the approach presented in (Bakre and Badrinath, 1995) interrupts transport layer communication up to 1.4 seconds. Our approach cuts down interruption time to a constant amount of time. Special requirements on a mobility supporting network layer e.g. mobile IP are needed. We focus on the migration of buffer contents to the new transport gateway. Strategies to minimize the communication overhead and migration time are discussed in detail.
Properties of a Center/Surround Retinex: Part 2. Surround Design (1995)

The last version of Edwin Land''s retinex model for human vision''s lightness and color constancy has been implemented. Previous research has established the mathematical foundations of Land''s retinex but has not examined specific design issues and their effects on the properties of the retinex operation. Here we have sought to define a practical implementation of the retinex without particular concern for its validity as a model for human lightness and color perception. Here we describe issues involved in design the surround function. We find that there is a trade-off between rendition and dynamic range compression that is governed by the surround space constant. Various functional forms for the retinex surround are evaluated and a Gaussian form found to perform better than the inverse square suggested by Land. Preliminary testing led to the design of a Gaussian surround with a space constant of 80 pixels as a reasonable compromise between dynamic range compression and rendition.
Poynting Vector and the Physical Meaning of Nonactive Powers (2005)

This paper explains how the disputed energy oscillations associated with nonactive powers can be attributed to electromagnetic waves that travel back and forth between the transmission line's sending and receiving ends. Such waves "hug" the conductors and dwell in the dielectric that surrounds the conductors. The propagation of these energy waves and the density of their rate of flow may be observed with the help of the Poynting Vector. This approach, based on the electromagnetic fields theory, explains the true physical mechanism of energy propagation in power systems and helps to interpret correctly the power expressions in three-phase systems.
The Reduction of Semiconductor Laser Phase Noise for Sensor Applications (1986)

Semiconductor lasers are particularly attractive as sources for optical sensors. However, if they are to be incorporated in unbalanced interferometric sensors their phase noise must be reduced. This paper describes methods by which this may be achieved using (a) passive optical feedback from an array of mirrors or optical fibres, and (b) active control of the laser drive current from the output of an interferometer monitoring the laser emission.
A shaped-reflector high-power converter for a whispering-gallery mode gyrotron output (1995)

A dual-shaped dual-reflector synthesis technique is applied to the design of a quasi-optical antenna system in a high-power microwave application for which the primary radiator is not conveniently described as a point source (spherical constant-phase surface). In addition, the output beam is required to be focused, and neither the entrance nor the exit pupil is conveniently described as being circular. The synthesis technique developed is a generalization of a well-established method which has found widespread application in the design of dual-shaped reflectors for satellite communication, radio astronomy, etc. Removing the usual assumptions of point-source illumination and parallel-ray output, as well as circular entrance and exit pupils, however, leads to expressions which may find application in a broader class of shaped-reflector designs. A reflector system has been designed using the general synthesis procedure which we have developed. The system transforms the right-hand rotating TE/sub 15,2/ mode propagating in 50.8 mm (2 in) diameter circular waveguide at 110 GHz into the HE/sub 11/ mode in 31.8 mm (1.25 in) diameter corrugated waveguide. A brief description of the experimental verification of the device performance is given.
Exposure to Ozone Modulates Human Airway Protease/Antiprotease Balance Contributing to Increased Influenza A Infection (2012)

Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA) is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs) human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2), whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI). Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs) to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility.
Molecular cloning and characterization of a sym plasmid locus that regulates cultivar‐specific nodulation of soybean by <i>Rhizobium fredii</i> USDA257 (1993)

Rhizobium fredii strain USDA257 produces nitrogen-fixing nodules on primitive soybean cultivars such as Peking but fails to nodulate agronomically improved cultivars such as McCall. Transposon-mutant 257DH4 has two new phenotypes: it nodulates McCall, and its ability to do so is sensitive to the presence of parental strain USDA257, i.e. it is subject to competitive nodulation blocking. We have isolated a cosmid containing DNA that corresponds to the site of transposon insertion in 257DH4 and have localized Tn5 on an 8.0 kb EcoRI fragment. The 5596 bp DNA sequence that surrounds the insertion site contains seven open reading frames. Five of these, designated nolBTU, ORF4, and nolV, are closely spaced and of the same polarity. nolW and nolX are of the opposite polarity. The initiation codon for nolW lies 155 bp upstream from that of nolB, and its is separated from nolX by 281 bp. The predicted NolT and NolW proteins have putative membrane-spanning regions. The N-terminus of the hypothetical NolW protein also has limited homology to NodH of Rhizobium meliloti, but none of the deduced protein sequences has significant homology to known nodulation gene products. Site-directed mutagenesis with mudII1734 confirms that inactivation of nolB, nolT, nolU, nolV, nolW, or nolX extends host range for nodulation to McCall soybean. This phenotype could not be genetically dissected from sensitivity to competitive nodulation blocking. Expression of nolBTU and nolX is induced as much as 30-fold by flavonoid signal molecules, even though these genes lack nod-box promoters. Histochemical staining of McCall roots inoculated with nolB-, nolU-, or nolX-lacZ fusions verifies that these genes are expressed continuously from preinfection to the stage of the functional nodule. Although a nolU-ORF4-nolV clone hybridizes to a single 8.0 kb EcoRI fragment from 10 strains of R. fredii and broad-host-range Rhizobium sp. NGR234, hybridizing sequences are not detectable in other rhizobia.
Wine Antioxidants and Their Impact on Antioxidant Activity In Vivo (1997)

There has been considerable interest in the role of dietary antioxidants such as flavonoids in retarding the development of cardiovascular disease in human populations. Red wine is a rich source of flavonoid antioxidants. These compounds have been demonstrated to have potent antioxidant properties in vitro but their role as antioxidants in vivo remains to be proven. We have recently developed an enhanced chemiluminescent assay for antioxidant activity in biological fluids. This chapter describes the use of this technique to examine changes in serum antioxidant activity following the ingestion of red wine by healthy human volunteers.
Realtime-learning on an autonomous mobile robot with neural networks (2002)

We discuss the usage of neural network clustering techniques on a mobile robot, in order to build qualitative topologic environment maps. This has to be done in realtime, i.e. the internal world-model has to be adapted by the flow of sensor-samples without the possibility to stop this data flow. Our experiments are done in a simulation environment as well as on a robot, called ALICE.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
A quantitative analysis of the performance and scalability of distributed shared memory cache coherence protocols (1999)

Scalable cache coherence protocols have become the key technology for creating moderate to large-scale shared-memory multiprocessors. Although the performance of such multiprocessors depends critically on the performance of the cache coherence protocol, little comparative performance data is available. Existing commercial implementations use a variety of different protocols, including bit-vector/coarse-vector protocols, SCI-based protocols, and COMA protocols. Using the programmable protocol processor of the Stanford FLASH multiprocessor, we provide a detailed, implementation-oriented evaluation of four popular cache coherence protocols. In addition to measurements of the characteristics of protocol execution (e.g., memory overhead, protocol execution time, and message count) and of overall performance, we examine the effects of scaling the processor count from 1 to 128 processors. Surprisingly, the optimal protocol changes for different applications and can change with processor count even within the same application. These results help identify the strengths of specific protocols and illustrate the benefits of providing flexibility in the choice of cache coherence protocol.
Physiological roles for aerenchyma in phosphorus-stressed roots (2003)

Low phosphorus availability induces the formation of cortical aerenchyma in roots. The adaptive significance of this response is unknown. We hypothesized that aerenchyma may be helpful to low-phosphorus plants by reducing root respiratory and phosphorus requirements, thereby increasing the metabolic efficiency of soil exploration. To test this hypothesis we investigated aerenchyma formation, root respiration and tissue phosphorus concentration in maize and common bean genotypes in response to phosphorus availability and ethylene treatments. Genotypes differed substantially in their ability to form aerenchyma in response to low phosphorus. Aerenchyma formation was disproportionately correlated with reduced root respiration; roots with 30% cross-sectional area as aerenchyma had 70% less respiration than roots without aerenchyma. Aerenchyma formation was also proportionally correlated with reduced root phosphorus concentration. Variation in aerenchyma formation was correlated with root respiration and phosphorus concentration, regardless of whether such variation was caused genetically or by ethylene or phosphorus treatments. Results with isolated roots were confirmed by measurement of whole root respiration of intact maize plants. Our results support the hypothesis that aerenchyma formation reduces the respiratory and phosphorus requirements of soil exploration by roots, and thus, represents a useful adaptation to low phosphorus availability.
Aging Successfully: A Four-Factor Model (2011)

Abstract The study was designed to validate a model for a successful aging process and examine the gender differences in the aging process. Three hundred twelve participants who were 65 or older completed a Taiwan Social Change Survey that measures four factors that define successful aging process: including physical, psychological, social support, and leisure activity. Structural equation modeling analysis shows in addition to the three supporting variables, leisure activities is a significant factor related to successful aging process. The findings of the study verified that the proposed model is well supported by the data and fits well for both female and male populations. The findings of the study also suggest that, for gerontological researchers, leisure activities of old people deserve their attention when helping the old generation age well. Notes Note. The currency exchange rate between US and Taiwan is about 1:33. Note. Higher mean scores indicate positive side of each measurement variable.
Etching of polysilicon in inductively coupled Cl2 and HBr discharges. I. Experimental characterization of polysilicon profiles (2002)

Photoresist and oxide masked polysilicon samples were etched in a Lam TCP 9400SE, using both Cl2 and HBr discharges. A three variable (inductive power/rf bias power/flow rate) fractional factorial set of experiments was performed for the photoresist and oxide masked polysilicon samples. Complete experimental sets of profiles for polysilicon etching with both photoresist and oxide masks using Cl2 and HBr are presented. Additional experimental profiles showing the profile evolution with time are documented. The most striking features exhibited in the profiles are: (1) the greater polysilicon-to-photoresist selectivity exhibited by HBr over Cl2; (2) the increased sidewall deposition associated with photoresist over oxide masks; (3) the greater curvature or bowing of the sidewalls associated with the combination of photoresist masking, spacing, and Cl2 plasmas; (4) the more vertical sidewalls achieved with HBr; (5) the double faceting of the feature sidewalls under etching conditions accompanied by significant deposition; (6) the variation of photoresist facet angle associated with product deposition; (7) the delay in the onset of microtrenching while etching photoresist-masked samples with Cl2; (8) the greater microtrenching exhibited with oxide masking and Cl2 plasmas; and (9) the lack of microtrenching for the HBr etching.
Molecular Engineering of Dendritic Polymers and Their Application as Drug and Gene Delivery Systems (2007)

This review discusses the development of functional and multifunctional dendrimeric and hyperbranched polymers, collectively called dendritic polymers, with the objective of being applied as drug and gene delivery systems. In particular, using as starting materials known and well-characterized basic dendritic polymers, the review deals with the type of structural modifications to which these dendritic polymers were subjected for the development of drug carriers with low toxicity, high encapsulating capacity, a specificity for certain biological cells, and the ability to be transported through their membranes. Proceeding from functional to multifunctional dendritic polymers, one is able to prepare products that fulfill one or more of these requirements, which an effective drug carrier should exhibit. A common feature of the dendritic polymers is the exhibition of polyvalent interactions, while for multifunctional derivatives, a number of targeting ligands determine specificity, another type of group secures stability in biological milieu and prolonged circulation, while others facilitate their transport through cell membranes. Furthermore, dendritic polymers employed for gene delivery should be or become cationic in the biological environment for the formation of complexes with the negatively charged genetic material.
Flow cytometry techniques for studying cellular thiols. (1983)

Cellular thiols, and especially glutathione, act as scavenger nucleophiles and can protect against toxicity, mutagenicity, or transformation by ionizing radiation and many carcinogens. Development of a rapid assay to quantitate the cellular content of thiols could thus be useful in assessing or predicting cellular risk to damage. Several fluorescent thiol-reactive drugs, usually maleimide or bromobimane derivatives, have been described for use in histopathology. Most of these agents do not distinguish between protein and nonprotein thiols, and virtually all of these fluorescent stains have normally been used after fixation of the cells or tissues. We have found that some of the probes will, however, rapidly penetrate and bind within viable cells with little associated cytotoxicity; the amount bound can be easily quantified using flow cytometry. We have used several of these agents, in conjunction with fluorescence-activated cell sorting in V79 spheroids, to examine the thiol content of cells as a function of their depth or position in the spheroid. Additionally, the radiation response of cells from different depths has been assessed following addition of exogenous thiols including glutathione and WR-2721, or after treatment with thiol-depleting agents, including DL-buthionine-S,R-sulfoximine (BSO), diethylmaleate (DEM), and dimethylfumarate (DMF). Our studies indicate that examination of the thiol content and radiation response of the sorted cells provides an improved understanding of the modes of action of these compounds.
A new type of mitogenic factor produced by <i>Streptococcus pyogenes</i> (1992)

A new type of mitogenic factor (protein) was purified from the culture supernatant of a strain of Streptococcus pyogenes by SP-Sephadex C-25 column chromatography, preparative isoelectric focusing and reversed-phase high-performance liquid chromatography. The purified factor, showing marked mitogenic activity in rabbit peripheral blood lymphocytes, gave a single-band staining for protein on SDS-PAGE. The molecular weight of the purified mitogenic factor was determined to be 25,370, which was different from those calculated from reported amino acid sequences deduced from 4 different nucleotide sequences of 3 kinds of streptococcal pyrogenic exotoxins (two SPEAs, SPEB and SPEC). The amino acid sequence of the N-terminal region of the purified mitogenic factor was determined to be Gln-Thr-Gln-Val-Ser-Asn-Asp-Val-Val-Leu-Asn-Asp-Gly-Ala-Ser-Lys-Tyr-Leu- Asn-Glu - Ala-, which was also different from the reported N-terminal sequences deduced from the 4 different nucleotide sequences. These data indicate that this mitogenic factor is distinct from the already described streptococcal pyrogenic exotoxins.
Targeting at the Speed of Light (2007)

Is laser energy just a better bullet, bomb or missile? Or will laser energy be a disruptive technology that could enable a U.S. advantage in the operational environment of 2025? If so, how will laser weapon systems be used in the operational environment of the future. Uncertainty and change are the predictions for the future. Many predict a future of accelerating change. That assumption significantly weakens forecasting estimates and increases risk for any organization. The consequence of a rapidly changing environment, with respect to military capabilities, exposes the United States to increased security risk. The U.S. military, as an instrument of power, must be able to mitigate or overcome security challenges. Laser weapons offer a disruptive capability to minimize these challenges and continue the traditional warfare advantage of the U.S. in the air, space and maritime domains. Understanding the science and technology of laser energy is crucial to understanding potential strengths and weaknesses as lasers are weaponized. This comprehension allows insight to the value of lasers as a future weapon system. Laser weapon systems will offer speed, ultraprecision, minimal collateral effects and deep magazines that enable temporal and spatial control of the air, space and maritime domains. Laser weapon systems will allow an increase in targets available in the operational environment, increase dynamic targeting and further compress the kill chain. This paper attempts to capture the military utility of laser weapons systems in the context of targeting, weaponeering and operational implications using laser weapon system capabilities described in the Draft 2006 Air Force Directed Energy Master Plan employed with current doctrine against present-day targets.
Pyridoxal phosphate-dependent reactions in the biosynthesis of natural products (2018)

Covering: up to mid-2018 Pyridoxal 5'-phosphate (PLP) is a versatile organic cofactor used to catalyze diverse reactions on amino acid, oxoacid, and amine substrates. Here we review the reactions catalyzed by PLP-dependent enzymes, highlighting enzymes reported in the natural product biosynthetic literature. We describe enzymes that catalyze transaminations, Claisen-like condensations, and β- and γ-eliminations and substitutions, along with epimerizations, decarboxylations, and transaldolations. Finally, we describe a newly reported group of O2-, PLP-dependent enzymes. Altogether, natural product biosynthesis showcases the incredible versatility of PLP-dependent transformations for building chemical complexity.
Saline Flush Test (2015)

Confirmation of central venous catheter placement by dynamic sonographic visualization of a saline flush with exclusion of pneumothorax is an accurate, safe, and more efficient method than confirmation by chest radiography. It allows the central line to be used immediately, expediting patient care.
Mapping a tyrosinaseless mutant of Neurospora (1963)

Mapping a tyrosinaseless mutant of Neurospora