gebhart/patrepeval huggingface dataset:
Novel technique for dynamic surface tension and viscosity measurements at liquid–gas interfaces (1978)

A novel means of generating and detecting surface waves at liquid-gas interfaces has been successfully developed. Electrocapillarity is used to generate the waves which are detected via specular reflection of a laser beam from the fluid surface to a position sensitive photodiode. Such a scheme is compact, sensitive, and does not mechanically touch the fluid surface. A preliminary study of highly damped waves on the magnetically oriented liquid crystal MBBA is reported.
Prevention of sexual transmission of HIV (2012)

HIV spread has reached a turning point following decades of increasing and sustained incidence. An effective vaccine has not been developed, but critical breakthroughs with prevention based on antiretroviral treatment are promising. The new prevention technologies will have to be combined with condoms and incorporated into the mixes of combination prevention approaches that are tailored to the local epidemic and context. To address the implementation gap, more political will and leadership will be needed to overcome the socio-cultural, legal or religious barriers to prevention. We have learned that the generation of demand for HIV prevention is not easy, as for health promotion in general. Despite optimism about treatment as prevention, many western countries are facing an increase in new HIV cases, and HIV is no longer a collective concern. If we manage to find common ground on combination prevention, customize approaches to people's needs and exercise technical and political leadership, our decade may see the beginning of the end of the epidemic.
Object Class Recognition at a Glance (2006)

This video shows our real-time object class recognition system at work. Object class recognition is a very challenging problem. The difficulty lies in capturing the variability of appearance and shape of different objects belonging to the same class, while avoiding confusing objects from different classes. However, state of the art algorithms such as [2] are capable of delivering high classification accuracy at interactive speed when dealing with a limited number of classes (around ten). Following the texton-based modeling approach in [2] we have developed an application for real-time segmentation and recognition of objects placed on a table top (figure 1). The system comprises two steps: object segmentation and classification. First, each object region is separated from the table top. This happens by running a patch-based classifier which discriminates between the class “table” and everything else. This technique is very different from more conventional background subtraction and is robust with respect to shadows, light changes and camera shake or motion. Second, once all the non-table connected regions have been extracted, they are classified as belonging to one of fifteen object classes using the same discriminative technique. Each classifier is a random forests discriminative model [1], [3] using pixel difference features. The classifier is learned similarly to [2] to achieve maximum generalisation with high efficiency and is designed to be invariant both to rotation and to small changes in scale. Our features are computed on both the RGB image (thus providing information about appearance) and on the binary segmentation mask (thus capturing information about object shape). In the learnt random decision trees each node is hence associated to either appearance or shape. Figure 2 Fig. 2
α-Galactoside Uptake in <i>Rhizobium meliloti</i> : Isolation and Characterization of <i>agpA</i> , a Gene Encoding a Periplasmic Binding Protein Required for Melibiose and Raffinose Utilization (1998)

Rhizobium meliloti can occupy at least two distinct ecological niches; it is found in the soil as a free-living saprophyte, and it also lives as a nitrogen-fixing intracellular symbiont in root nodules of alfalfa and related legumes. One approach to understanding how R. meliloti alters its physiology in order to become an integral part of a developing nodule is to identify and characterize genes that are differentially expressed by bacteria living inside nodules. We used a screen to identify genes under the control of the R. meliloti regulatory protein NodD3, SyrM, or SyrA. These regulatory proteins are expressed by bacteria growing inside the root nodule. One gene isolated in this screen was mapped to pSymB and displayed complex regulation. The gene was downregulated by the syrA gene product and also by glucose and succinate. This gene, referred to as agpA, encodes a periplasmic binding protein that is most similar to proteins from the periplasmic oligopeptide binding protein family. It is likely that AgpA binds alpha-galactosides, because alpha-galactosides induce the expression of agpA, and agpA mutants cannot utilize or transport these sugars. Activity of an agpA::TnphoA fusion was downregulated by SyrA. Because syrA is known to be expressed at high levels in intracellular symbiotic R. meliloti and at low levels in the free-living bacteria, we propose that AgpA may belong to the class of gene products whose expression decreases when R. meliloti becomes an intracellular symbiont.
A Novel Asymmetric Clamping Cell for Measuring Streaming Potential of Flat Surfaces (2002)

A novel asymmetric clamping cell is used to measure the ζ potential of macroscopic sample surfaces. The unique design of the cell allows in-situ measurement of ζ potentials of any flat surfaces, either solids (such as glass, plastics, metals, and ceramics) or flexible sheets (like polymer films, papers, foils, and membranes), without having to cut or shape the test surfaces to fit the measuring cell dimensions. The cell enables measurement of the streaming potential through several parallel rectangular channels formed by firmly pressing a grooved spacer against the test surface. The term “asymmetric” specifically refers to the unique configuration of the channels, where one of the walls (the test surface) bears a different charging property (or, more specifically, ζ potential), compared to the other three surfaces of the channel (formed by the spacer). A mathematical formulation on the basis of Smoluchowski−Helmholtz approach reveals that the measured ζ potential in such a cell represents the average ζ potential of the test surface and the spacer material. Several surfaces, including clean glass disk, aminosilane modified glass, polymeric membrane, and poly(methyl methacrylate) (PMMA) plate, were tested using the cell. The ζ potentials of the polymeric membrane obtained using the present cell were compared with the corresponding potentials measured using the traditional rectangular cell, and good agreement between the two measurements was observed. The asymmetric cell can be used in conjunction with standard commercially available streaming potential analyzers.
Protective Properties of Viscoelastic Substances (Sodium Hyaluronate and 2% Hydroxymethylcellulose) Against Experimental Free Radical Damage to the Corneal Endothelium (1993)

Hydrogen peroxide (H2O2) has potent oxidant properties due to the action of free radicals (OH.) induced from its degradation. The free radicals specie derived from H2O2 are extremely toxic to the corneal endothelium and quickly induce corneal edema. In the present work, in order to ascertain the endothelial cell protection from viscoelastic substances, we have studied experimental corneal endothelial cell damage caused in the rabbit eye after intracameral injection of different H2O2 concentrations, with and without previous filling and washing out of two widely used viscoelastic substances from the anterior chamber such as 1% sodium hyaluronate (Healon) and hydroxypropylmethylcellulose (HPMC). We observed a dose-dependent endothelial damage in the controls. The experimental groups protected with Healon or HPMC showed statistically fewer corneal endothelial cell lesions than the control group (p < 0.001) for all of the concentrations used. Healon showed superior protective properties than HPMC at higher H2O2 concentrations (100 mM). However, HPMC was superior with 1 and 10 mM peroxide. From this experimental evidence, we conclude that Healon and HPMC are effective as protectors against the corneal endothelial lesions caused by free radicals. This finding may explain some of the beneficial effects of these viscoelastic substances.
Developmental stage‐specific multi‐subunit plastid RNA polymerases (PEP) in wheat (1999)

Most photosystem I and II plastid genes are transcribed by a plastid encoded Escherichia coli-like RNA polymerase (PEP). In this study, we show that both promoter selectivity and light-dependency of PEP change dramatically during development in wheat leaves. In the leaf tip, psbA and psbD promoter activities are light induced, whilst psbC, psbE and 16S rRNA promoters do not function efficiently irrespective of light conditions. In contrast to the leaf tip, in the basal portion all PEP promoters studied function in the dark as well as the light, except for psbD. Using in vitro transcription, we found that PEP in the illuminated leaf tip can initiate transcription from the -35 destructed psbA promoter, but the -35 element is essential for transcription in the basal portion. There is an extended -10 element in the psbA promoter, recognized by the PEP in the illuminated leaf tip or purified sigma 70-type Escherichia coli RNA polymerase but not by the PEP in the leaf base. These results suggest that during wheat leaf development, PEP in the leaf base that is functional for most PEP promoters even in the dark is replaced by the light-dependent PEP selectively transcribing the psbA and psbD promoters.
Photoconductive properties of aceanthraquinoxaline and related pyrazines (1969)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoconductive properties of aceanthraquinoxaline and related pyrazinesAleksandar GolubovicCite this: J. Phys. Chem. 1969, 73, 5, 1352–1356Publication Date (Print):May 1, 1969Publication History Published online1 May 2002Published inissue 1 May 1969https://doi.org/10.1021/j100725a029RIGHTS & PERMISSIONSArticle Views50Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (446 KB) Get e-Alerts
Oxidative discolouration in whole-head and cut lettuce: biochemical and environmental influences on a complex phenotype and potential breeding strategies to improve shelf-life (2017)

Abstract Lettuce discolouration is a key post-harvest trait. The major enzyme controlling oxidative discolouration has long been considered to be polyphenol oxidase (PPO) however, levels of PPO and subsequent development of discolouration symptoms have not always correlated. The predominance of a latent state of the enzyme in plant tissues combined with substrate activation and contemporaneous suicide inactivation mechanisms are considered as potential explanations for this phenomenon. Leaf tissue physical properties have been associated with subsequent discolouration and these may be influenced by variation in nutrient availability, especially excess nitrogen and head maturity at harvest. Mild calcium and irrigation stress has also been associated with a reduction in subsequent discolouration, although excess irrigation has been linked to increased discolouration potentially through leaf physical properties. These environmental factors, including high temperature and UV light intensities, often have impacts on levels of phenolic compounds linking the environmental responses to the biochemistry of the PPO pathway. Breeding strategies targeting the PAL and PPO pathway biochemistry and environmental response genes are discussed as a more cost-effective method of mitigating oxidative discolouration then either modified atmosphere packaging or post-harvest treatments, although current understanding of the biochemistry means that such programs are likely to be limited in nature and it is likely that they will need to be deployed alongside other methods for the foreseeable future.
Colorectal cancer prevention in inflammatory bowel disease and the role of 5-aminosalicylic acid: A clinical review and update (2007)

A roundtable consensus meeting was held to consolidate current knowledge on the etiology of colorectal cancer in patients with inflammatory bowel disease and to review current strategies, both diagnostic and preventive, specifically addressing the role of 5-aminosalicylic acid. Specific topics that were addressed included: the epidemiology of colorectal cancer, including an assessment of risk factors and the impact of colonoscopy on colorectal cancer incidence and mortality; the origin and evolution of dysplasia nomenclature and the natural history of dysplasia; review of the experience of St. Mark's Hospital (London) as gleaned from its surveillance database; mechanisms by which 5-aminosalicylic acid is thought to exert a chemopreventive effect; the potential future role of 5-aminosalicylic acid in chemopreventive strategies; chemoprevention in familial adenomatous polyposis; and other future research directions. This article provides a comprehensive overview of the issues discussed and should act as a guide to shaping the design of future studies in this area.
Modeling and Performance of NAS in Inclement Weather (2006)

The current demand in the National Airspace System (NAS) is rapidly approaching the system capacity. This capacity limit causes significant congestion and delay in off-nominal conditions, such as inclement weather. It will also constrain future growth in the aviation sector. Transformation of the current system can relieve this constraint. Examples of such transformation include (i) flight schedule shifting to periods of low demand or alternate airports, (ii) air traffic control (ATC) productivity enhancements, (iii) new procedures and airspace redesigns, and (iv) improvements in weather nowcasting and forecasting. Planners are now investigating such NAS architecture strategies. This paper describes research and plans regarding our investigation of future NAS performance in inclement weather days. Our NAS simulation allows researchers and decision makers to hypothesize strategies in various weather conditions and traffic demand levels to quantify the combined impact on the NAS. The results of the simulation will guide decisions regarding the value of investments in weather forecasting technology and NAS procedures. Our simulation approach is to use (i) archived weather and traffic schedule data with (ii) weather and traffic forecasting models and (iii) tactical weather vectoring and stochastic traffic flow management capabilities.
Effect of particle size of bronchodilator aerosols on lung distribution and pulmonary function in patients with chronic asthma. (1987)

The particle size of bronchodilator aerosols may be important in determining the site of deposition in the lung and their therapeutic effect. The distribution of aerosols (labelled with technetium-99m diethylene triamine pentacetic acid) of two different particle sizes has been studied by gamma camera imaging. The particles had mass median aerodynamic diameters (geometric standard deviations) of 1.4 (1.4) and 5.5 (2.3) micron, and they were administered from a jet nebuliser to eight patients with chronic severe stable asthma. There was no significant difference in peripheral lung deposition with the two aerosols in any patient. The bronchodilator effect of the two aerosols was determined from cumulative dose-response studies. To avoid large doses that might mask possible differences in effect due to aerosol size, small, precisely determined incremental amounts of salbutamol (25-250 micrograms total lung dose) were used. The two doses were given via a nebuliser on separate occasions and the bronchodilator response was measured from FEV1, forced vital capacity, and peak expiratory flow 30 minutes after each dose. Bronchodilatation was similar with the two aerosols at each dose of salbutamol. There was therefore no difference in distribution within the lung or any difference in bronchodilator effect between an aerosol of small (1.4 micron) particle size and an aerosol of 5.5 microns in patients with severe but stable asthma.
Repression of the cell wall protein gene operon in Bacillus brevis 47 by magnesium and calcium ions (1991)

Transcription from P2, one of the major promoters of the cell wall protein gene operon of Bacillus brevis 47, was markedly enhanced at the early stationary phase of growth. MgCl2, when added at 1 to 5 mM to the medium, inhibited this enhancement of transcription as well as shedding of the cell wall protein layers from the cell surface. MgSO4 or CaCl2 showed an effect similar to that of MgCl2. The possible coordination of the cell wall structure with regulation of the cell wall protein genes is discussed.
Expression in <i>Escherichia coli</i>, purification and characterization of two mammalian thioesterases involved in fatty acid synthesis (1991)

Thioesterase I, a constituent domain of the multifunctional fatty acid synthase, and thioesterase II, an independent monofunctional protein, catalyse the chain-terminating reaction in fatty acid synthesis de novo at long and medium chain lengths respectively. The enzymes have been cloned and expressed in Escherichia coli under the control of the temperature-sensitive lambda repressor. The recombinant proteins are full-length catalytically competent thioesterases with specificities indistinguishable from those of the natural enzymes.
An electrophysiological analysis of the synthesis of acetylcholine in preganglionic nerve terminals (1972)

1. An electrophysiological analysis has been made of the synthesis of acetylcholine (ACh) in the preganglionic nerve terminals of the isolated superior cervical ganglion of the guinea‐pig. The mean amplitude of excitatory post‐synaptic potentials recorded intracellularly was taken as a measure of the ACh output per impulse from the terminals of a preganglionic axon. 2. Prolonged repetitive stimulation of the cervical sympathetic trunk at 10 and 20 Hz led to a decline in ACh output over the first 5‐15 min and then a maintained output for periods of up to an hour. The mean level of maintained output was 0·4 of the peak initial output. 3. The maintained level of output was shown to be equal to the rate of synthesis of new transmitter and was not dependent on the addition of choline (3 × 10 −5 M ) to the fluid in the organ bath. 4. The ACh output per minute was shown to be directly proportional to the frequency of stimulation. 5. A model has been proposed of the storage and synthesis of ACh in preganglionic nerve terminals during prolonged stimulation, in which choline from the hydrolysis of released ACh is the main source of substrate for synthesis of new transmitter, and the rate at which synthesis proceeds is controlled by the rate at which transmitter is released.
Real-space multiple-scattering calculation and interpretation of x-ray-absorption near-edge structure (1998)

A self-consistent real-space multiple-scattering (RSMS) approach for calculations of x-ray-absorption near-edge structure (XANES) is presented and implemented in an ab initio code applicable to arbitrary aperiodic or periodic systems. This approach yields a quantitative interpretation of XANES based on simultaneous, self-consistent-field (SCF) calculations of local electronic structure and x-ray absorption spectra, which include full multiple scattering from atoms within a small cluster and the contributions of high-order MS from scatterers outside that cluster. In addition, the code includes a SCF estimate of the Fermi energy and an account of orbital occupancy and charge transfer. We also present a qualitative, scattering-theoretic interpretation of XANES. Sample applications are presented for cubic BN, ${\mathrm{UF}}_{6},$ Pu hydrates, and distorted ${\mathrm{PbTiO}}_{3}.$ Limitations and various extensions are also discussed.
What the nucleolus says to a tumour pathologist (2009)

The importance of nucleolar changes in cancer cells is underestimated in tumour pathology. There is evidence that the nucleolus is the mirror of a series of metabolic changes that characterize cancer cells. Cell entry into the cell cycle is always associated with up-regulation of the nucleolar function and increased nucleolar size, which are also directly dependent on the rapidity of cell cycle progression. Furthermore, alterations of the major tumour suppressor retinoblastoma (Rb) and p53 pathways also contribute to the stimulation of nucleolar function and to nucleolar enlargement. High cell growth fraction, high cell growth rate and disruption of the Rb and p53 pathways are responsible for greater aggressiveness of cancer tissues. Therefore, the evaluation of nucleolar size allows one to obtain reliable information on the clinical outcome of the cancer: the greater the nucleolar size, the worse the tumour prognosis. Indeed, a series of studies carried out on numerous human tumours has shown that nucleolar hypertrophy (prominent nucleolus) was an independent predictive and prognostic parameter of a fatal clinical outcome.
SoC Feedback Control for Wind and ESS Hybrid Power System Frequency Regulation (2013)

With increased penetration of wind generation, the traditional control scheme of the wind turbine (WT), which is designed for maximum wind power extraction, is no longer suitable to meet emerging grid requirements for wind farms to participate in frequency regulation. The control scheme of the WT with respect to grid frequency regulation is proposed in many studies, such as those on pitch control. Also, energy storage technologies have drawn much attention in recent years because, as technology matures and costs decrease, they present themselves as a potential solution for the challenge brought about by the uncertainty of renewable energy generation with regard to power system stability. A power system consisting of a high penetration of wind generation and energy storage systems (ESS) is investigated in this paper for the regulation of grid frequency. A new strategy called state of charge (SoC) feedback control is proposed, and the performance of the grid frequency deviation response and the SoC of the battery are presented. The model of the power system studied in this paper is established on the MATLAB/SIMULINK platform.