353 research outputs found

    Superfluidity in a Doped Helium Droplet

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    Path Integral Monte Carlo calculations of the superfluid density throughout ^4He droplets doped with linear impurities (HCN)_n are presented. After deriving a local estimator for the superfluid density distribution, we find a decreased superfluid response in the first solvation layer. This effective normal fluid exhibits temperature dependence similar to that of a two-dimensional helium system.Comment: 4 pages, 6 figure

    Quantitative sensory testing of the equine face

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    Background: Quantitative sensory testing methods are now standard in the evaluation of sensory function in man, while few normal equine values have been reported. Objectives: The aim of this experimental study was (a) to define the tactile sensory, mechanical nociceptive and thermal nociceptive thresholds of the equine face; (b) to assess the effect of age, sex, stimulation site and shaving; (c) to evaluate the reliability of the methods and (d) to provide reference facial quantitative sensory testing values. Study design: Method description. Methods: Thirty-four healthy Warmblood horses were used in the study. Six (tactile sensory threshold) and five (mechanical nociceptive and thermal nociceptive thresholds) areas of the left side of the face with clear anatomical landmarks were evaluated. Ten horses had two (mechanical nociceptive threshold) or three (tactile sensory and thermal nociceptive thresholds) of these areas shaved for another study. A linear Mixed model was used for data analysis. Results: All thresholds increased with age (tactile sensory threshold: by 0.90 g/y (CI = [0.12 g; 0.36 g]) P = .001; mechanical nociceptive threshold: by 0.25 N/y (CI = [0.13-0.36 N]) P = .000; thermal nociceptive threshold: by 0.2°C/y (CI = [0.055-0.361]) P = .008). Sex had no effect on thresholds (tactile sensory threshold: P = .1; mechanical nociceptive threshold: P = .09; thermal nociceptive threshold: P = .2). Stimulation site affected tactile sensory and mechanical nociceptive thresholds (P = .001 and P = .008), but not thermal nociceptive threshold (P = .9). Shaving had no significant effect on any of the thresholds (tactile sensory threshold: P = .06; mechanical nociceptive threshold: P = .08; thermal nociceptive threshold: P = .09). Main limitations: Only the left side was investigated and measurements were obtained on a single occasion. Conclusions: Handheld quantitative sensory testing does not require shaving or clipping to provide reliable measurements. Stimulation over the nostril (tactile sensory threshold), temporomandibular joint (mechanical nociceptive threshold) and supraorbital foramen (thermal nociceptive threshold) resulted in the most consistent thresholds

    Ground-state properties and superfluidity of two- and quasi two-dimensional solid 4He

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    In a recent study we have reported a new type of trial wave function symmetric under the exchange of particles and which is able to describe a supersolid phase. In this work, we use the diffusion Monte Carlo method and this model wave function to study the properties of solid 4He in two- and quasi two-dimensional geometries. In the purely two-dimensional case, we obtain results for the total ground-state energy and freezing and melting densities which are in good agreement with previous exact Monte Carlo calculations performed with a slightly different interatomic potential model. We calculate the value of the zero-temperature superfluid fraction \rho_{s} / \rho of 2D solid 4He and find that it is negligible in all the considered cases, similarly to what is obtained in the perfect (free of defects) three-dimensional crystal using the same computational approach. Interestingly, by allowing the atoms to move locally in the perpendicular direction to the plane where they are confined to zero-point oscillations (quasi two-dimensional crystal) we observe the emergence of a finite superfluid density that coexists with the periodicity of the system.Comment: 16 pages, 8 figure

    Induce the plant resistance to pathogen infection

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    Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broad spectrum of microorganisms. Salicylic acid (SA) is the signal molecule which is required for induce SAR and is associated with accumulation of pathogenesis-related proteins, which are thought to contribute to resistance. SA paly vital role in some related resistance gene expression in plant cell which have direct or indirect effect on pathogen growth as SA has direct toxicity for pathogen and in the same time has stimulation effect for some enzyme related to reduce the oxidative burst

    Induce the plant resistance to pathogen infection

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    Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broadspectrum of microorganisms. Salicylic acid (SA) is the signal molecule which is required for induce SAR and is associated with accumulationof pathogenesis-related proteins, which are thought to contribute to resistance. SA paly vital role in some related resistance gene expression inplant cell which have direct or indirect effect on pathogen growth as SA has direct toxicity for pathogen and in the same time has stimulationeffect for some enzyme related to reduce the oxidative burst

    Epiphytic microbiota of apple in integrated and organic growing

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    The surface microbial contamination is of great interest in case of fruits, since they are they potential sources of spoilage or foodborne diseases. The aim of this work was to compare the epiphytic microbiota of food safety concern of different apple cultivars as a function of cultivation methods (organic versus integrated), production year and place. Investigating 47 samples it was found that the average microbial contamination of the apple surfaces was within a certain range,, practically independent of cultivar, growing area and year. The frequency distribution of the surface bacterial, mould and yeast counts did not show significant differences between growing technologies or varieties. The principal component analysis the samples ranked the apple samples into seven groups on the basis of their microbial contamination level, and the discriminant analysis proved the goodness of grouping. The grouping was independent from cultivars and growing methods. No foodborne pathogen Salmonella spp. and Listeria spp. were found on the surfaces of apples

    Organoleptic evaluation of pear varieties grown at different sites

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    It was stated as a summary that a system of testing pear varieties on scale of 100 degrees, weighing 11 properties, gives a comprehensive information on qualities of pear varieties. The points of the form to be filled out, distinguishes the appreciation of accessory flavours and tastes from the main properties. Under the title of taste, sweet and acid taste are evaluated separately. The presently used system is a step forward as the composed characters do not influence the judgement of each other. In the representation of results, the 100 degree system was more efficacious than the usual 5-point system because there was no need of using fractions, and the graphic profile is more expressive, so the commodity is better visualised. The assembly of the jury was divided into two groups as below and above 35 year old persons. The two groups judged differently the acidity, sweetness and the thickness of the fruit peel. It was suggested that the choice of the produce should consider the differences in taste and give up the idea of being equally favourable for both groups. The samples of different growing sites revealed that the best quality is produced at Nagykanizsa, and this capacity would be able to supply the market also in the large super-markets and chain of department stores in Hungary

    Epiphytic microbiota of apple in integrated and organic growing

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    The surface microbial contamination is of great interest in case of fruits, since they are they potential sources of spoilage or foodbornediseases. The aim of this work was to compare the epiphytic microbiota of food safety concern of different apple cultivars as a functionof cultivation methods (organic versus integrated), production year and place. Investigating 47 samples it was found that the average microbialcontamination of the apple surfaces was within a certain range,, practically independent of cultivar, growing area and year. The frequencydistribution of the surface bacterial, mould and yeast counts did not show significant differences between growing technologies or varieties.The principal component analysis the samples ranked the apple samples into seven groups on the basis of their microbial contamination level,and the discriminant analysis proved the goodness of grouping. The grouping was independent from cultivars and growing methods. No foodbornepathogen Salmonella spp. and Listeria spp. were found on the surfaces of apples

    Sensorial appraisal of sour cherries grown by environmental technology

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    Sour cherry samples have been tested by a panel of potential consumers, and the judgments expressed by points given for each attribute. The correlation of individual traits with “general impression” has been explored. Primary raising of data was aimed to evaluate the effect of environmental growing technology upon sensorial impression of fruits for fresh consumption. Organoleptic tests consist of tasting and filling out of forms with numerical data as ratings them regarding taste, flavour and flesh firmness. The values of coefficients of correlation showed that a couple of other attributes as appearance, juiciness and sugar/acids perceived were irrelevant from the point of view of acceptance, i. e. the general impression
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