29,732 research outputs found

    Potato root eelworm, DD, and soil sterilization. I. Methods and criteria

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    RESP-276

    Generalized (m,k)-Zipf law for fractional Brownian motion-like time series with or without effect of an additional linear trend

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    We have translated fractional Brownian motion (FBM) signals into a text based on two ''letters'', as if the signal fluctuations correspond to a constant stepsize random walk. We have applied the Zipf method to extract the ζ\zeta ' exponent relating the word frequency and its rank on a log-log plot. We have studied the variation of the Zipf exponent(s) giving the relationship between the frequency of occurrence of words of length m<8m<8 made of such two letters: ζ\zeta ' is varying as a power law in terms of mm. We have also searched how the ζ\zeta ' exponent of the Zipf law is influenced by a linear trend and the resulting effect of its slope. We can distinguish finite size effects, and results depending whether the starting FBM is persistent or not, i.e. depending on the FBM Hurst exponent HH. It seems then numerically proven that the Zipf exponent of a persistent signal is more influenced by the trend than that of an antipersistent signal. It appears that the conjectured law ζ=2H1\zeta ' = |2H-1| only holds near H=0.5H=0.5. We have also introduced considerations based on the notion of a {\it time dependent Zipf law} along the signal.Comment: 24 pages, 12 figures; to appear in Int. J. Modern Phys

    Promoting independent learning skills using video on digital language laboratories

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    This is the author's PDF version of an article published in Computer assisted language learning ©2006. The definitive version is available at http://www.informaworld.com/The article discusses the potential for developing independent learning skills using the digital language laboratory with particular reference to exploiting the increasingly available resource of digital video. It investigates the potential for recording and editing video clips from online sources and digitalising clips from analogue recordings and reflects on the current status quo regarding the complex copyright regulations in this area. It describes two pilot self-access programmes based on video clips which were undertaken with University College Chester undergraduates and reflects on the value of the experience for students in developing a wide range of language skills as well as independent learning skills using their feedback on the experience

    Maximally entangled mixed states: Creation and concentration

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    Using correlated photons from parametric downconversion, we extend the boundaries of experimentally accessible two-qubit Hilbert space. Specifically, we have created and characterized maximally entangled mixed states (MEMS) that lie above the Werner boundary in the linear entropy-tangle plane. In addition, we demonstrate that such states can be efficiently concentrated, simultaneously increasing both the purity and the degree of entanglement. We investigate a previously unsuspected sensitivity imbalance in common state measures, i.e., the tangle, linear entropy, and fidelity.Comment: 4 pages, 3 figures, 1 table; accepted versio

    Teaching a New Dog Old Tricks: Resurrecting Multilingual Retrieval Using Zero-shot Learning

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    While billions of non-English speaking users rely on search engines every day, the problem of ad-hoc information retrieval is rarely studied for non-English languages. This is primarily due to a lack of data set that are suitable to train ranking algorithms. In this paper, we tackle the lack of data by leveraging pre-trained multilingual language models to transfer a retrieval system trained on English collections to non-English queries and documents. Our model is evaluated in a zero-shot setting, meaning that we use them to predict relevance scores for query-document pairs in languages never seen during training. Our results show that the proposed approach can significantly outperform unsupervised retrieval techniques for Arabic, Chinese Mandarin, and Spanish. We also show that augmenting the English training collection with some examples from the target language can sometimes improve performance.Comment: ECIR 2020 (short

    Diagnosis of glaucoma by indirect classifiers

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    Objectives: Demonstration of the applicability of a framework called indirect classification to the example of glaucoma classification. Indirect classification combines medical a priori knowledge and statistical classification methods. The method is compared to direct classification approaches with respect to the estimated misclassification error. Methods: Indirect classification is applied using classification trees and the diagnosis of glaucoma. Misclassification errors are reduced by bootstrap aggregation. As direct classification methods linear discriminant analysis, classification trees and bootstrap aggregated classification trees are utilized in the problem of glaucoma diagnosis. Misclassification rates are estimated via 10-fold cross-validation. Results: Indirect classification techniques reduce the misclassification error in the context of glaucoma classification compared to direct classification methods. Conclusions: Embedding a priori knowledge into statistical classification techniques can improve misclassification results. Indirect classification offers a framework to realize this combination

    Национальная модель мира в живописном мифотворчестве Владимира Кабаченко

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    Urinary bladder cancer is a historical disease of rubber workers often been associated with exposure to aromatic amines such as 2-naphthylamine. While exposure to these compounds has decreased markedly over time, the bladder cancer risk has not decreased in direct proportion. Polycyclic aromatic compounds (PAC) are candidates for urinary bladder cancer causation. We determined pre- and post-exposure urinary levels of 2-napthol (2NAP), the major metabolite of a model volatile PAC, in a group of non-smoking rubber workers. Pre- and post-exposure urine samples were collected from 43 non-smoking workers. Overall mean post-shift 2-naphthol levels were increased (13.95 ± 28.4 μg/l), but non-significantly compared to samples collected pre-exposure (7.97 ± 22.1 μg/l; p=0.29). The greatest difference was observed in the curing department where post-exposure samples were 4.5 fold higher, post shift samples were significantly higher in production workers as compared to non-production workers (p=0.02). Levels of 2NAP were not correlated with levels of carcinogen-DNA adducts in exfoliated urothelial cells nor with other estimates of exposure or effect. These data suggest that post-shift urinary 2NAP levels are increased, particularly in the curing department. However, the differences were not significantly different overall and urinary 2NAP levels did not predict the level of carcinogen DNA adducts in exfoliated urothelial cells

    Hospitality entrepreneurs managing quality of life and business growth

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    The hospitality industry is dominated by small- and medium-sized enterprises (SMEs).They are often led by entrepreneurs who face the challenge of simultaneously managing business decisions and their own wellbeing. The competitiveness of tourism destinations often depends on these entrepreneurs and therefore understanding their motivations and work patterns is critical. Research on individual wellbeing increasingly builds on the concept of quality of life (QoL). Hospitality and tourism literature so far predominantly focused on investigating QoL for tourists and residents, rather than for entrepreneurs’ QoL, even though being key stakeholders in the hospitality industry. Therefore, this study explores the factors influencing hospitality entrepreneurs’ quality of life (“HE-QoL”) and how these relate to business growth. Results of a 380 hospitality entrepreneurs’ survey identify six distinct factors of HE-QoL. Two groups of HE-QoL are identified with significant differences in fitness level activity, entrepreneurial competencies and business growth. Findings lead to recommendations to reduce stress to improve HE-QoL, and to develop entrepreneurial competencies, which help to cope with entrepreneurial challenges. Tourism destinations and politics can support hospitality entrepreneurs in these actions by creating conditions that foster social exchange in regional communities and trust in political and economic stability

    How to pinpoint energy-inefficient Buildings? An Approach based on the 3D City model of Vienna

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    This paper describes a methodology to assess the energy performance of residential buildings starting from the semantic 3D city model of Vienna. Space heating, domestic hot water and electricity demand are taken into account. The paper deals with aspects related to urban data modelling, with particular attention to the energy-related topics, and with issues related to interactive data exploration/visualisation and management from a plugin-free web-browser, e.g. based on Cesium, a WebGL virtual globe and map engine. While providing references to existing previous works, only some general and introductory information is given about the data collection, harmonisation and integration process necessary to create the CityGML-based 3D city model, which serves as the central information hub for the different applications developed and described more in detail in this paper. The work aims, among the rest, at developing urban decision making and operational optimisation software tools to minimise non-renewable energy use in cities. The results obtained so far, as well as some comments about their quality and limitations, are presented, together with the discussion regarding the next steps and some planned improvements

    Photocleavage of the Polypeptide Backbone by 2-Nitrophenylalanine

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    SummaryPhotocleavage of the polypeptide backbone is potentially a powerful and general method to activate or deactivate functional peptides and proteins with high spatial and temporal resolution. Here we show that 2-nitrophenylalanine is able to photochemically cleave the polypeptide backbone by an unusual cinnoline-forming reaction. This unnatural amino acid was genetically encoded in E. coli, and protein containing 2-nitrophenylalanine was expressed and site-specifically photocleaved
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