gebhart/patrepeval huggingface dataset:
Advanced IEEE 802.11ax TCP aware scheduling under unreliable channels (2019)

Summary In this paper, we suggest advanced IEEE 802.11ax (WiFi) TCP‐aware scheduling strategies for optimizing the TCP Goodput AP operation under transmission of unidirectional TCP traffic to downloading stations. Our scheduling strategies optimize the TCP Goodput performance using the capability for Multi User transmissions over the Uplink, first introduced in IEEE 802.11ax, together with Multi User transmissions over the Downlink. The scheduling strategies are based on Transmission Opportunities (TXOP), and we suggest three scheduling strategies determining the TXOP formation parameters. In one of the strategies, one can control the achieved TCP Goodput vs the delay. We also assume saturated TCP transmission queues. We show that with minimal TCP Goodput degradation, one can avoid considerable delays: It turns out that for TCP Data segments of 1460 bytes, achieving optimal TCP Goodput requires TXOPs of 25 ms, while if one loses only 5% of the optimal Goodput, TXOPs can be of only 3 ms. For TCP Data segments of 256 bytes, the TXOPs are of 13 and 5 ms, respectively.
On the mechanism of anionic polymerization of maleic anhydride, 2 (1973)

Abstract The triphenyl and tributyl phosphine initiated polymerization of maleic anhydride was investigated. The structure of the macro zwitterions, formed under the given reaction conditions, depended on the initiator employed. If the polymerization was initiated by triphenyl phosphine, the macromolecules contained succinic anhydride units and cyclopentanone derivatives, formed from further rearrangement. If, however, tributyl phosphine was employed as initiator, the polymers were mostly made up of conjugated ketoolefinic units. IR, NMR and mass spectrometric measurements were carried out to determine the structure of the polymers. Existence of the macro zwitterions was proved by high voltage electrophoresis. The semi‐conductor properties of the polymers containing conjugated ketoolefinic units are discussed. Spectroscopic investigation of the kinetics of the triphenyl phosphine initiated polymerization of maleic anhydride showed that the initiation reaction of the ylide, formed with the monomer, proceeded about 90 times slower than the propagation reaction due to addition of the monomer to the growing chain‐end.
A Zwitterionic Surfactant Bearing Unsaturated Tail for Enhanced Oil Recovery in High‐Temperature High‐Salinity Reservoirs (2018)

Abstract High‐temperature/high‐salinity (HTHS) reservoirs contain a significant fraction of the world's remaining oil in place and are potential candidates for enhanced oil recovery (EOR). Selection of suitable surfactants for such reservoirs is a challenging task. In this work, two synthesized zwitterionic surfactants bearing a saturated and an unsaturated tail, namely 3‐( N ‐stearamidopropyl‐ N , N ‐dimethyl ammonium) propanesulfonate and 3‐( N ‐oleamidopropyl‐ N , N ‐dimethyl ammonium) propanesulfonate, respectively, were evaluated. The surfactant with the unsaturated tail showed excellent solubility in synthetic seawater (57,643 ppm) and in formation brine (213,734 ppm). However, the unsaturated surfactant with a saturated tail showed poor solubility, and therefore it was not evaluated further. The thermal stability of the synthesized unsaturated surfactant solution in seawater was evaluated by heating the solution at 90 °C in a sealed aging tube for 2 weeks. The thermal stability of the unsaturated surfactant was confirmed by FTIR and NMR analysis of the aged samples at such harsh conditions. The critical micelle concentration (CMC) of the synthesized unsaturated surfactant in seawater was 1.02 × 10 −4 mol L −1 , while the surface tension at CMC was 30 mN m −1 . The synthesized unsaturated surfactant was able to reduce the oil–water interfacial tension to ~10 −1 mN m −1 at different conditions. A commercial copolymer of acrylamide and 2‐acrylamido‐2‐methylpropane sulfonic acid (AM‐AMPS) was tested for EOR applications in HTHS conditions. The addition of the synthesized unsaturated surfactant to the AM‐AMPS copolymer increased the viscosity of the system. The increase in oil recovery by injecting the unsaturated surfactant solution and the surfactant–polymer mixture in solution was 8 and 21%, respectively. The excellent properties of the synthesized unsaturated surfactant show that surfactants with an unsaturated tail can be an excellent choice for HTHS reservoirs.
Normal prion protein has an activity like that of superoxide dismutase (1999)

We show here that mouse prion protein (PrP(C)) either as recombinant protein or immunoprecipitated from brain tissue has superoxide dismutase (SOD) activity. SOD activity was also associated with recombinant chicken PrP(C) confirming the evolutionary conserved phenotype suggested by sequence similarity. Acquisition of copper by PrP(C) during protein folding endowed SOD activity on the protein but the addition of copper following refolding did not. PrP(C) dependent SOD activity was abolished by deletion of the octapeptide-repeat region involved in copper binding. These results describe an enzymic function for PrP(C) consistent with its cellular distribution and suggest it has a direct role in cellular resistance to oxidative stress.
Obesity and type 2 diabetes (2011)

Obesity and type 2 diabetes (T2DM) are public health problems, with health consequences and economic costs that have raised concern worldwide. The increase in the prevalence of diabetes parallels that of obesity. Some experts call this dual epidemic ‘diabesity’ Elevated body mass index (BMI) and waist circumference (WC) were significantly associated T2DM. One consequence of obesity is an increased risk of developing T2DM. There is evidence that the prenatal, early childhood, and adolescent periods are critical in the development of obesity. Most obese individuals have elevated plasma levels of free fatty acids (FFA), which are known to cause peripheral (muscle) insulin resistance. Weight loss either with lifestyle modification, pharmacotherapy or bariatric surgery improves glycemic control and metabolic parameters that are related to cardiovascular disease. Pharmacotherapy for glycemic control with metformin or GLP-1 agonists and DPP-4 inhibitors help in weight reduction.
Sequence-Defined Transposon Mutant Library of Burkholderia thailandensis (2013)

The Gram-negative bacterium Burkholderia pseudomallei is a biothreat agent due to its potential for aerosol delivery and intrinsic antibiotic resistance and because exposure produces pernicious infections. Large-scale studies of B. pseudomallei are limited by the fact that the organism must be manipulated under biological safety level 3 conditions. A close relative of B. pseudomallei called Burkholderia thailandensis, which can be studied under less restrictive conditions, has been validated as a low-virulence surrogate in studies of virulence, antibiotic resistance and other traits. To facilitate large-scale studies of B. thailandensis, we created a near-saturation, sequence-defined transposon mutant library of the organism. The library facilitates genetic studies that identify genotype-phenotype associations conserved in B. pseudomallei.
Vector sensor processing for electromagnetic source localization (2002)

A novel approach is presented for the localization of electromagnetic sources using vector sensors. Two types of source transmissions are considered: (1) single signal transmission and (2) dual signal transmission. The model is given in terms of several parameters including the wave direction of arrival and state of polarization. A compact expression is derived for the Cramer-Rao bound (CRB) on the estimation errors of these parameters for the multi-source multi-vector sensor model. The advantage of using vector sensors is highlighted by explicit evaluation of the CRB and the associated mean-square angular error for source localization with a single vector sensor. A simple algorithm is proposed for estimating the source DOA with this sensor.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Therapeutic actions of garlic constituents (1996)

Most studies on garlic during the past 15 years have been primarily in the fields of cardiovascular and cancer research. Cardiovascular studies have been mainly related to atherosclerosis, where effects were examined on serum cholesterol, LDL, HDL, and triglycerides. Although the studies were not consistent in relation to the dosage, standardization of garlic preparations, and period of treatment, most findings suggest that garlic decreases cholesterol and triglycerides levels in patients with increased levels of these lipids. Lowering of serum lipids by garlic ingestion may decrease the atherosclerosis process. The other major beneficial effect of garlic is due to its antithrombotic actions. This field of garlic research has been extensively studied. Garlic extracts and several garlic constituents demonstrate significant antithrombotic actions both in vitro and in vivo systems. Allicin and adenosine are the most potent antiplatelet constituents of garlic because of their in vitro effects. Since both allicin and adenosine are rapidly metabolized in human blood and other tissues, it is doubtful that these compounds contribute to any antithrombotic actions in the body. In addition, ajoene also seems not to be an active antiplatelet principle, because it is not naturally present in garlic, garlic powders, or other commercial garlic preparations. Only a small amount of ajoene can be found in garlic oil-macerates; however, ajoene is being developed as a drug for treatment of thromboembolic disorders. Recent findings on the identification of potent enzyme inhibiting activities of adenosine deaminase and cyclic AMP phosphodiesterase in garlic extracts are interesting, and may have a significant role in the pharmacological actions in the body. Presence of such enzyme inhibitors in garlic may perhaps explain several clinical effects in the body, including the antithrombotic, vasodilatory, and anticancer actions. Epidemiological studies have suggested that garlic plays a significant role in the reduction of deaths caused by malignant diseases. This had led many investigators to examine garlic and garlic constituents for their antitumor and cytotoxic actions both in vitro and in laboratory animals. The data from these investigations suggest that garlic contains several potentially important agents that possess antitumor and anticarcinogenic properties. In summary, the epidemiological, clinical, and laboratory data have proved that garlic contains many biologically and pharmacologically important compounds, which are beneficial to human health from cardiovascular, neoplastic, and several other diseases. Numerous studies are in progress all over the world to develop effective and odorless garlic preparations, as well as to isolate the active principles that may be therapeutically useful.
Internet time synchronization: the network time protocol (1991)

The network time protocol (NTP), which is designed to distribute time information in a large, diverse system, is described. It uses a symmetric architecture in which a distributed subnet of time servers operating in a self-organizing, hierarchical configuration synchronizes local clocks within the subnet and to national time standards via wire, radio, or calibrated atomic clock. The servers can also redistribute time information within a network via local routing algorithms and time daemons. The NTP synchronization system, which has been in regular operation in the Internet for the last several years, is described, along with performance data which show that timekeeping accuracy throughout most portions of the Internet can be ordinarily maintained to within a few milliseconds, even in cases of failure or disruption of clocks, time servers, or networks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Are modern voice prostheses better? A lifetime comparison of 749 voice prostheses (2013)

The aim of the study was to compare device life of more recent indwelling voice prostheses Provox Vega and Blom-Singer Dual Valve to device life of well-known standard devices (Provox 2, Blom-Singer Classic). In a prospective, non-randomised study, device life of Blom-Singer Classic, Blom-Singer Dual Valve, Provox2, Provox Vega and Provox ActiValve voice prostheses was recorded in a group of 102 laryngectomised patients. In total 749 voice prosthesis were included. Average overall life time was 108 days, median 74 days. The prosthesis with the longest dwell time was the Provox ActiValve (median 291 days). Provox Vega had longer device life compared with Provox2 (median 92 days vs 66 days; p = 0.006) and compared with Blom-Singer Classic (median 92 days vs 69 days; p = 0.004). In conclusion, device lifetimes of Provox Vega and ActiValve were better than those of Provox2 and the Blom-Singer Classic. New voice prostheses, with a defined valve opening pressure (Provox Vega, Provox ActiValve, Blom-Singer Dual Valve) had longer lifetimes than prostheses without a defined opening pressure (Blom-Singer Classic and Provox 2).
A Conformation Change in the Carboxyl Terminus of Alzheimer's Aβ(1–40) Accompanies the Transition from Dimer to Fibril as Revealed by Fluorescence Quenching Analysis (2000)

Alzheimer's disease is characterized by the presence of insoluble, fibrous deposits composed principally of amyloid beta (Abeta) peptide. A number of studies have provided information on the fibril structure and on the factors affecting fiber formation, but the details of the fibril structure are not known. We used fluorescence quenching to investigate the solvent accessibility and surface charge of the soluble Abeta(1-40) dimer and amyloid fibrils. Analogs of Abeta(1-40) containing a single tryptophan were synthesized by substituting residues at positions 4, 10, 34, and 40 with tryptophan. Quenching measurements in the dimeric state indicate that the amino-terminal analogs (AbetaF4W and AbetaY10W) are accessible to polar quenchers, and the more carboxyl-terminal analog AbetaV34W is less accessible. AbetaV40W, on the other hand, exhibits a low degree of quenching, indicating that this residue is highly shielded from the solvent in the dimeric state. Correcting for the effect of reduced translational and rotational diffusion, fibril formation was associated with a selective increase in solvent exposure of residues 34 and 40, suggesting that a conformation change may take place in the carboxyl-terminal region coincident with the dimer to fibril transition.
Experimental Study of Aerosol Filtration in the Transition Flow Regime (1992)

An experimental study was carried out to investigate the performance of fibrous filters in the transition flow regime, where the fiber radius is of the same order of magnitude as the mean free path of gas molecules. Filter media with the mean fiber diameter of 0.21–0.72 μm and the packing density of 0.053–0.08 were used in this study. The transition flow conditions were achieved by reducing the gas pressure in the filter test apparatus. Experiments were performed in the pressure range of 0.1–1.0 atm using monodisperse particles of 0.04–0.45-μm diameter range. The particles were generated by the electrostatic classification technique. The particulate penetration through the filter and the corresponding pressure drop were measured at face velocities ranging from 6 to 19 cm/s. Experimental results showed that the penetration decreased by three to four orders of magnitude as the pressure was reduced from 1.0 to 0.1 atm. It was found that the most penetrating particle size increased slightly as the gas pressure was reduced. The pressure drop across the filter was also found to decrease significantly as the pressure was reduced.
Distribution of virulence genes in Salmonella serovars isolated from man & animals. (2003)

Findings indicated that the stn gene is widely distributed among Salmonella irrespective of the serovars and source of isolation. However, the sef gene appears to be serovar specific. Since the stn gene is found in all the isolates, it can be a viable target gene to explore the possibility of direct detection of Salmonella from samples from biological sources.
A GSM simulation platform for intrusion detection (2002)

We present a mobile network simulator which has been developed in accordance to the GSM phase 1 technical specifications. The resulting platform is able to simulate the whole network as well as the mobile stations at the protocol level. The modular approach adopted for the GSM simulator and the functional architecture allow the network model part of the program to be easily ported to various applications. The simulator is used in order to test a generic intrusion detection architecture for mobile networks. Other applications based on the layer-3 signalling analysis could easily be implemented with such a platform.
Transfer and Transcriptional Expression of Coleopteran cryIIIB Endotoxin Gene of Bacillus thuringiensis in Eggplant (1995)

Three constructs of a coleopteran toxic cryIIIB Bacillus thuringiensis gene were engineered and incorporated into eggplant (Solanum melongena L.). Southern blot analysis of the eight primary transformants and segregational analysis of their R, progenies indicated that the chimeric cryIIIB constructs in each of the transgenic plants were stably incorporated at a single locus or at multiple sites within the same linkage group and that they were regularly transmissible to the progeny. The results of Northern blot and RNase protection analyses demonstrated that transcription of the cryIIIB mRNA takes place in plant cells, but only a small amount of the expected entire length transcripts were produced. The amount of the 5' end mRNA fragment produced was at least 30 to 40 times more abundant than the amount of the 3' end mRNA fragment. This could be interpreted to mean that either the two ends of the mRNA are of different stability or that the transcription process is often interrupted and only a few mRNAs complete the entire process to the end. When the transgenic plant mRNA was reverse-transcribed, amplified by polymerase chain reaction, and hybridized to the cryIIIB probe, two smaller molecular weight mRNA species were identified. Thus, the preponderance of the cryIIIB mRNA in transgenic plants exists as a truncated species, a situation similar to that of cryI genes when expressed in transgenic plants. Seedlings from the eight independent transgenic plants were tested for Coleopteran insect resistance. However, they did not demonstrate any significant resistance to the first and second instar larvae of the Colorado potato beetle (Leptinotarsa decemlineata Say).
A Large-Scale Study of Flash Memory Failures in the Field (2015)

Servers use flash memory based solid state drives (SSDs) as a high-performance alternative to hard disk drives to store persistent data. Unfortunately, recent increases in flash density have also brought about decreases in chip-level reliability. In a data center environment, flash-based SSD failures can lead to downtime and, in the worst case, data loss. As a result, it is important to understand flash memory reliability characteristics over flash lifetime in a realistic production data center environment running modern applications and system software.
Use of synthetic polymer hydrogels to prepare scaffoldless 3D tissue constructs (2013)

<ns4:p>The use of 3-dimensional tissue cultures is gaining popularity in many fields including drug discovery, toxicity testing and tissue engineering. Currently most of the techniques used to prepare these 3D tissues are time consuming and cannot be reproduced easily. There is an urgent need to optimize the preparation of these 3D tissue cultures. This study evaluated the use of synthetic hydrogel polymers used to manufacture soft contact lenses to guide cells to form multicellular tissue-like structures. It was found that bovine chondrocytes and porcine dental pulp stem cells were able to form 3D tissue structures when placed inside a soft contact lens. Commercially available microarrays, 96 or 384 well plates manufactured using synthetic hydrogel polymers may help overcome many reproducibility issues and simplify the 3D tissue culture process.</ns4:p>
Overview of experience with the Shell Coal Gasification Process (1993)

AbstractAn integrated coal gasification combined cycle system has major efficiency and environmental advantages and is therefore regarded as a natural candidate for new coal-based power generation projects. The Shell Coal Gasification Process (SCGP) is in the forefront of coal gasification technology. Wide experience was gained with development (Shell Amsterdam Laboratory), pilot (Deutsche Shell, Harburg refinery) and demonstration units (SCGP-1, Houston, USA). SCGP flexibility has been demonstrated for feeds ranging from bituminous coals to lignites and petroleum coke, and the process is well suited for combined cycle power generation. The first commercial application of the Shell technology is presently under construction in the Netherlands by Demkolec for the Dutch utilities. The plant is scheduled to start up in the second half of 1993.Keywords: coal gasificationtechnologycommercial plant
Irreversible Change of Pore Structure of MCM-41 upon Hydration at Room Temperature (1998)

The pore structure stability of MCM-41 materials upon hydration/dehydration was studied by XRD, 29Si MAS NMR, and gravimetric adsorption techniques. Results demonstrated that collapses of the pore structure of MCM-41 occurred upon rehydration at room temperature due to the hydrolysis of the bare Si−O−Si(Al) bonds in the presence of water vapor. Full structure collapses of MCM-41 were found to occur when a MCM-41 sample was left in air for three months. It is also suggested that care must be taken when XRD is used to evaluate the structure property of MCM-41 materials to avoid the possible adverse effects of water vapor.