734 research outputs found

    Effects of the presence of skins during alcoholic fermentation on the composition of wine volatiles

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    Der Einfluß des Beerenhautkontaktes während der alkoholischen Gärung auf die Zusammensetzung der WeinaromakomponentenDie Zusammensetzung der flüchtigen und nichtflüchtigen Inhaltsstoffe von Weinen, die aus einem Most der Rebsorte Cencibel unter vier verschiedenen Gärungsbedingungen gewonnen wurden, wird beschrieben. Die Vergärung durch Saccharomyces cerevisiae erfolgte mit oder ohne Beerenhäute und mit oder ohne SO2. Die mittels konventioneller Analysenmethoden und auf gaschromatographischem Wege gewonnenen Daten wurden der Faktoren- und Clusteranalyse unterzogen. Bei einigen Komponenten traten signifikante Konzentrationsunterschiede in Abhängigkeit von den Gärungsbedingungen auf

    Temporal characterization of the requests to Wikipedia

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    This paper presents an empirical study about the temporal patterns characterizing the requests submitted by users to Wikipedia. The study is based on the analysis of the log lines registered by the Wikimedia Foundation Squid servers after having sent the appropriate content in response to users' requests. The analysis has been conducted regarding the ten most visited editions of Wikipedia and has involved more than 14,000 million log lines corresponding to the traffic of the entire year 2009. The conducted methodology has mainly consisted in the parsing and filtering of users' requests according to the study directives. As a result, relevant information fields have been finally stored in a database for persistence and further characterization. In this way, we, first, assessed, whether the traffic to Wikipedia could serve as a reliable estimator of the overall traffic to all the Wikimedia Foundation projects. Our subsequent analysis of the temporal evolutions corresponding to the different types of requests to Wikipedia revealed interesting differences and similarities among them that can be related to the users' attention to the Encyclopedia. In addition, we have performed separated characterizations of each Wikipedia edition to compare their respective evolutions over time

    A quantitative examination of the impact of featured articles in Wikipedia

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    This paper presents a quantitative examination of the impact of the presentation of featured articles as quality content in the main page of several Wikipedia editions. Moreover, the paper also presents the analysis performed to determine the number of visits received by the articles promoted to the featured status. We have analyzed the visits not only in the month when articles awarded the promotion or were included in the main page, but also in the previous and following ones. The main aim for this is to assess the attention attracted by the featured content and the different dynamics exhibited by each community of users in respect to the promotion process. The main results of this paper are twofold: it shows how to extract relevant information related to the use of Wikipedia, which is an emerging research topic, and it analyzes whether the featured articles mechanism achieve to attract more attention

    Actualidad de la meteorologĂ­a espacial

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    Recognition and management of hereditary colorectal cancer syndromes

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    Over 1,900 colorectal tumors will arise in association with a hereditary colorectal cancer syndrome in Spain in 2009. The genetic defects responsible for the most common syndromes have been discovered in recent years. Genetic testing helps diagnose affected individuals and allows identification of individuals at-risk. Colonoscopy and prophylactic colectomy decrease colorectal cancer incidence and overall mortality in patients with hereditary colon cancer. Extracolonic tumors are frequent in these syndromes, so specific surveillance strategies should be offere

    On the distribution of source code file sizes

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    Source code size is an estimator of software effort. Size is also often used to calibrate models and equations to estimate the cost of software. The distribution of source code file sizes has been shown in the literature to be a lognormal distribution. In this paper, we measure the size of a large collection of software (the Debian GNU/Linux distribution version 5.0.2), and we find that the statistical distribution of its source code file sizes follows a double Pareto distribution. This means that large files are to be found more often than predicted by the lognormal distribution, therefore the previously proposed models underestimate the cost of software

    A revised approach to the ?<i>o</i>F2 long-term trends analysis

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    International audienceA new approach to extract foF2 long-term trends, which are free to a great extent from solar and geomagnetic activity effects, has been proposed. These trends are insensitive to the phase (increasing/decreasing) of geomagnetic activity, with long-term variations being small and insignificant for such relatively short time periods. A small but significant residual foF2 trend, with the slope Kr = - 2.2 Ă— 10-4 per year, was obtained over a 55-year period (the longest avail-able) of observations at Slough. Such small trends have no practical importance. On the other hand, negative (although insignificant) residual trends obtained at 10 ionosonde stations for shorter periods (31 years) may be considered as a manifestation of a very long-term geomagnetic activity increase which did take place during the 20th century. All of the revealed foF2 long-term variations (trends) are shown to have a natural origin related to long-term variations in solar and geomagnetic activity. There is no indication of any manmade foF2 trends. Key words. Ionosphere (ionosphere-atmosphere interactions, ionospheric disturbances

    Behavior of the ionosphere over Europe during two geomagnetic storms which caused tongues of ionization over North America

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    Poster presentado en la EGU General Assembly 2015, 12-17 April, 2015, Vienna, AustriaThis work presents the effect of two geomagnetic storms on the ionospheric total electron content (TEC) over Europe. Those geomagnetic storms occurred on July 14th, 2013 and February 19th, 2014 and originated a tongue of ionization over North America. Following the criteria of Gonzalez et al.(1994), the July storm can be classified as a moderate one because the Dst index reached a value of -72nT, whereas the February storm as an intense event considering that Dst index dropped to -112nT. For this study we have used RINEX files obtained from GNSS stations belonging to International GPS Service, IGS, EUREF Permanent Network, and University Navstar Consortium, UNAVCO, networks. The data has been divided into two groups in function of the region: Europe or North America. For each group we have used all the available stations. The RINEX files have been processed using a technique developed by Ciraolo (2012) which assumes the ionospheric thin shell model to obtain the vertical total electron content (vTEC) from the slant total electron content (sTEC) at the Ionospheric Pierce Point, IPP, the point where the line-of-sight between the satellite and the ground receiver intersects the ionosphere. The data were obtained at 1 minute sampling in periods of geomagnetic storms and quiet days close to them. In both storms a tongue of ionization, ToI, appeared over North America from afternoon to dusk (between 19:00 and 3:00 GMT). The behavior of the ionosphere over Europe was very different in eachcase. In July, the TEC decreased respect the quiet days during the ToI time. In the February storm the behavior of the ionosphere over Europe was similar to that of a quiet day but the following day appeared a phenomenom similar to the ToI.Peer reviewe

    Long-term <i>hm</i>F2 trends in the Eurasian longitudinal sector from the ground-based ionosonde observations

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    International audienceThe method earlier used for the foF2 long-term trends analysis is applied to reveal hmF2 long-term trends at 27 ionosonde stations in the European and Asian longitudinal sectors. Observed M(3000)F2 data for the last 3 solar cycles are used to derive hmF2 trends. The majority of the studied stations show significant hmF2 linear trends with a confidence level of at least 95% for the period after 1965, with most of these trends being positive. No systematic variation of the trend magnitude with latitude is revealed, but some longitudinal effect does take place. The proposed geomagnetic storm concept to explain hmF2 long-term trends proceeds from a natural origin of the trends rather than an artificial one related to the thermosphere cooling due to the greenhouse effect

    Overview of Neutrino–Nucleus Interactions

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    Neutrino–nucleus reactions are surveyed. The approximations usually made are identified and a comparison to the corresponding electron–nucleus processes is presented. Impulse Approximation (IA), factorization of the cross-section and scaling approaches (SA) to lepton–nucleus scattering are examined in detail
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