1,536 research outputs found

    Spectral statistics of the quenched normal modes of a network-forming molecular liquid

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    We evaluate the density of states of the quenched normal modes of ST2 water, and their statistical fluctuations, for a range of densities spanning three regimes of behavior of a hydrogen bonded liquid: a lower-density regime of random tetrahedral network formation; in the vicinity of a liquid-liquid critical point; and in a higher-density regime of fragile glass-forming behavior. For all cases we find that the fluctuations around the mean spectral densities obey the predictions of the Gaussian orthogonal ensemble of random matrix theory. We also measure the participation ratio of the normal modes across the entire frequency range, and find behavior consistent with the majority of modes being of an extended nature, rather than localized.Comment: Accepted for publication in The Journal of Chemical Physic

    Effect of sulphur supplementation on micronutrients, fatty acids and sulphur use efficiency of soybean seeds

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    The present study was aimed at finding the influence of different sources and doses of sulphur fertilizers on micronutrient status and oil composition in soybean seeds. Soybean is the major source of edible vegetable oils and high protein seed supplements in the world. Sulphur deficiency causes soybean protein quality to decline and also decreases nitrogen-use efficiency of fertilizers. Soybean is a good source of nutrients which could further be amended with biofortification and use of fertilizers, to meet the nutrient deficiencies. Various limiting factors affect the yield of soybean crop by affecting the yield potential. Sufficient sulphur deficiency is one such limiting factor and have become common all over due to intensive crop systems and higher yielding varieties. Micronutrients play an important role in quality and quantity of soybean yield. Sulphur fertilizers viz gypsum and single super phosphate (SSP) were used at three different doses. Soil analysis have been done to evaluate the fertility status of soil prior to the experiment. Different treatments of sulphur supplementation had significant effect on seed micronutrient accumulation, nitrogen sulphur ratio and fatty acid profile. Sulphur supplementation increased zinc and iron content in mature soybean seeds, however, copper and manganese were found to be least effective. Sulphur supplementation with gypsum @ 20 kgha-1 increased plant height and pods per plant. Increase of oleic acid coincided with the decrease of linoleic acid with sulphur supplementation during both the cropping seasons of study

    Effect of uncorrected astigmatism on vision

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    PURPOSE: To examine the effect of uncorrected astigmatism in older adults. SETTING: University Vision Clinic METHOD: Twenty-one healthy presbyopes, aged 58.9±2.8 years, had astigmatism of 0.0 to -4.0 x 90?DC and -3.0DC of cylinder at 90?, 180? and 45? induced with spectacle lenses, with the mean spherical equivalent compensated to plano, in random order. Visual acuity was assessed binocularly using a computerised test chart at 95%, 50% and 10% contrast. Near acuity and reading speed were measured using standardised reading texts. Light scatter was quantified with the cQuant and driving reaction times with a computer simulator. Finally visual clarity of a mobile phone and computer screen was subjectively rated. RESULTS: Distance visual acuity decreased with increasing uncorrected astigmatic power (F=174.50, p0.05), but the reliability and variability of measurements decreased with increasing uncorrected astigmatic power (p0.05), but subjective rating of clarity decreased with increasing uncorrected astigmatic power (p<0.001). Uncorrected astigmatism at 45? or 180? orientation resulted in a worse distance and near visual acuity, and subjective rated clarity than 90? orientation (p<0.05). CONCLUSION: Uncorrected astigmatism, even as low as 1.0DC, causes a significant burden on a patient’s vision. If left uncorrected, this could impact significantly on their independence, quality of life and wellbeing

    Astigmatism and vision:should all astigmatism always be corrected?

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    As technology and medical devices improve, there is much interest in when and how astigmatism should be corrected with refractive surgery. Astigmatism can be corrected by most forms of refractive surgery, such as using excimer lasers algorithms to ablate the cornea to compensate for the magnitude of refractive error in different meridians. Correction of astigmatism at the time of cataract surgery is well developed and can be achieved through incision placement, relaxing incisions and toric intraocular lens (IOL) implantation. This was less of an issue in the past when there was a lower expectation to be spectacle independent after cataract surgery, in which case the residual refractive error, including astigmatism, could be compensated for with spectacle lenses. The issue of whether presurgical astigmatism should be corrected can be considered separately depending on whether a patient has residual accommodation, and the type of refractive surgery under consideration. We have previously reported on the visual impact of full correction of astigmatism, rather than just correcting the mean spherical equivalent. Correction of astigmatism as low as 1.00 dioptres significantly improves objective and subjective measures of functional vision in prepresbyopes at distance and near

    Ground surface temperature and continental heat gain: uncertainties from underground

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    Temperature changes at the Earthʼs surface propagate and are recorded underground as perturbations to the equilibrium thermal regime associated with the heat flow from the Earthʼs interior. Borehole climatology is concerned with the analysis and interpretation of these downward propagating subsurface temperature anomalies in terms of surface climate. Proper determination of the steady-state geothermal regime is therefore crucial because it is the reference against which climate-induced subsurface temperature anomalies are estimated. Here, we examine the effects of data noise on the determination of the steady-state geothermal regime of the subsurface and the subsequent impact on estimates of ground surface temperature (GST) history and heat gain. We carry out a series of Monte Carlo experiments using 1000 Gaussian noise realizations and depth sections of 100 and 200 m as for steady-state estimates depth intervals, as well as a range of data sampling intervals from 10 m to 0.02 m. Results indicate that typical uncertainties for 50 year averages are on the order of ±0.02 K for the most recent 100 year period. These uncertainties grow with decreasing sampling intervals, reaching about ±0.1 K for a 10 m sampling interval under identical conditions and target period. Uncertainties increase for progressively older periods, reaching ±0.3 K at 500 years before present for a 10 m sampling interval. The uncertainties in reconstructed GST histories for the Northern Hemisphere for the most recent 50 year period can reach a maximum of ±0.5 K in some areas. We suggest that continuous logging should be the preferred approach when measuring geothermal data for climate reconstructions, and that for those using the International Heat Flow Commission database for borehole climatology, the steady-state thermal conditions should be estimated from boreholes as deep as possible and using a large fitting depth range (~100 m)

    Intentionality and power interplay in IS implementation : The case of an asset management firm

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    This paper evaluates the interplay between intentionality of stakeholders, organizational power and information systems (IS) implementation in the context of an European firm implementing an Enterprise Resource Planning system. We found that the implementation coincided with significant restructuring of power relations within the firm. We also found that the intentions of various stakeholders came to bear in terms of how organizational power got manifested. Our findings suggest a complex interplay between individual intentions and organizational power. Specifically, our study contributes to the literature by providing insights into the systemic nature of organizational power regarding IS implementations and how it relates to individual intentionsinfo:eu-repo/semantics/publishedVersio
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