121,776 research outputs found
Estudio de la invasión mundial de Nicotiana glauca Graham mediante una aproximación combinada genética y ecológica
No full textFil: Issaly, E. Andrés. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Las especies exóticas son aquellas que han sido introducidas por la acción humana, de manera accidental o intencional, en una nueva región alejada de su rango nativo potencial. Tras superar determinadas barreras ambientales, reproductivas y dispersivas en el nuevo hábitat, solo algunas de estas especies se adaptan al nuevo medio, se multiplican y logran tener una alta abundancia de individuos, constituyéndose en invasoras, las cuales pueden generar diversos impactos ambientales en los ecosistemas invadidos. Comprender cómo y desde dónde se introdujeron las especies invasoras es crucial para explicar el éxito de la invasión y proporcionar conocimientos esenciales para un manejo efectivo. En este estudio se combinó un enfoque filogeográfico con modelados de nicho ecológico para dilucidar el modo y la fuente de introducción de Nicotiana glauca, una planta nativa de América del Sur que constituye una especie invasora a nivel mundial. A partir de la diversidad genética y las comparaciones de nicho climático entre el rango nativo y áreas invadidas por la especie, en la presente tesis, se evaluaron tres escenarios con modalidades de introducción diferentes: una fuente nativa aleatoria, una fuente nativa restringida y una fuente secundaria no nativa (bridgehead). Cada uno de estos escenarios implica diferentes predicciones genéticas y ecológicas acerca del proceso de invasión. Dentro del rango nativo, se identificaron tres linajes genéticos que se diferenciaron geográfica y climáticamente. Sin embargo, solo uno de estos linajes genéticos contenía los haplotipos presentes en las regiones invadidas, aunque no mostró superposición en el nicho climático con ninguna de las áreas invadidas. Por otro lado, se observó que una zona invadida en el oeste de Sudamérica, con mayor diversidad genética que otras áreas invadidas pero inferior a la del rango nativo, presentó superposición en el nicho climático con casi todas las demás áreas invadidas en todo el mundo. Estos hallazgos indican que probablemente N. glauca haya invadido inicialmente las áreas del oeste de Sudamérica, cercanas al rango nativo, estableciendo así una fuente secundaria o bridgehead, desde la cual la especie se ha dispersado hacia otras regiones del mundo, probablemente siguiendo rutas comerciales históricas. La capacidad invasora de la especie habría sido favorecida por cambios en las preferencias ambientales en el área bridgehead, ocupando climas más secos, fríos y menos estacionales, y convirtiéndose en la fuente principal de introducción hacia áreas climáticamente similares en todo el mundo. Los análisis a escala fina de resolución, combinando enfoques genéticos y climáticos dentro del rango nativo y el amplio rango invadido, han sido fundamentales para revelar la modalidad de introducción de esta especie. Los modelos de distribución potencial para N. glauca predicen que la especie podría ocupar un rango geográfico más amplio que el observado en los registros disponibles en la actualidad. Por su parte, las proyecciones en escenarios de cambio climático en el futuro sugieren que las regiones templadas del Hemisferio Norte tendrían el mayor riesgo de invasión. Esto podría indicar que la invasión de N. glauca aún no ha alcanzado su rango completo de expansión. Esta tesis destaca la relevancia de combinar la aproximación filogeográfica y los modelos de nicho ecológico al evaluar las fuentes y los modos de introducción. El enfoque teórico y metodológico utilizado en este estudio podría ser de importancia para investigar otras historias de invasión a nivel mundial.Fil: Issaly, E. Andrés. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Dissipative Range Scaling of Higher Order Structure Functions for Velocity and Passive Scalars
No full textDifferently to Kolmogorov's second similarity hypothesis, we find that the 2n-th order velocity and scalar structure functions scale with n-th order moment of the energy dissipation and the scalar dissipation, respectively. The origins of this scaling are analyzed by the transport equations of the fourth order velocity and scalar increment moments and by direct numerical simulations
Fast implementation of iterative adaptive approach for wideband unambiguous radar detection
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
Ratio of n-6/n-3 in the diets of beef cattle
No full textEffects of feeding heat-treated canola (C), soybean (S) and flax (F) or mixtures on growth and slaughter characteristics, taste and fatty acid (FA) composition of beef tissue were investigated using 128 crossbred steers to determine the potential of improving the nutritional quality of beef for humans. For Trial 1 (48 steers), dietary treatments were: roasted C, extruded C, roasted S, extruded S, roasted F and extruded F. For Trial 2 (80 steers), the dietary treatments were: S:F (1:1), S:C (1:1), C:F (1:1) and S:F:C (1:1:1), and the oilseeds were processed either by roasting or extruding before mixing. Soybean meal and soybean oil were used to give equivalent lipid and protein contents to each experimental diet. The basal diet consisted of grass silage, barley grain, vitamins and minerals. Steers were fed for a minimum of 100d then slaughtered at a uniform degree of finish. Growth and slaughter characteristics of the steers were only slightly affected by dietary treatment in that the soybean-fed steers consumed more feed and had a higher average daily gain than the canola or flax-fed animals in Trial 1. There was no difference in taste panel parameters for any of the treatments. Inclusion of flax in the diet increased the total n-3 content of meat. Similar results were found for canola and C18:1n-9 although this was not the case for soybean and the n-6 FA. For the n-6 FA in the PL and neutral lipid fractions of the meat samples, levels were correlated with high dietary levels of n-6 or n-9 with low levels of n-3 while for the n-3 FA, levels were correlated with high dietary n-3 levels and low n-6 levels. Oilseed processing method did not have an effect on any fatty acid levels. It is possible to modify the FA composition of beef meat toward a healthier profile by including heat-treated oilseeds in the diet to influence the degree of lipid metabolism in the rumen.ID: S0377840111004007; M3: Article; Accession Number: S0377840111004007; Author: M.A. McNiven (a, ⁎); Author: J.L. Duynisveld (b); Author: T. Turner (a); Author: A.W. Mitchell (a); Affiliation: Department of Health Management, Atlantic Veterinary College, University of PEI, Charlottetown, PEI, Canada C1A 4P3; Affiliation: Agriculture and Agri-Food Canada, Nappan, NS, Canada B0L 1C0; Keyword: Oilseeds; Keyword: Roasted; Keyword: Extruded; Keyword: Fatty acids; Keyword: Healthy fat; Number of Pages: 11; Language: English
After seven years in Key West, Florida, author John N. Cole learned to appreciat
No full textAfter seven years in Key West, Florida, author John N. Cole learned to appreciate Maine winters for their beauty and power
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Identifying idiolect in forensic authorship attribution: an n-gram textbite approach
No full textForensic authorship attribution is concerned with identifying authors of disputed or anonymous documents, which are potentially evidential in legal cases, through the analysis of linguistic clues left behind by writers. The forensic linguist “approaches this problem of questioned authorship from the theoretical position that every native speaker has their own distinct and individual version of the language [. . . ], their own idiolect” (Coulthard, 2004: 31). However, given the diXculty in empirically substantiating a theory of idiolect, there is growing concern in the Veld that it remains too abstract to be of practical use (Kredens, 2002; Grant, 2010; Turell, 2010). Stylistic, corpus, and computational approaches to text, however, are able to identify repeated collocational patterns, or n-grams, two to six word chunks of language, similar to the popular notion of soundbites: small segments of no more than a few seconds of speech that journalists are able to recognise as having news value and which characterise the important moments of talk. The soundbite oUers an intriguing parallel for authorship attribution studies, with the following question arising: looking at any set of texts by any author, is it possible to identify ‘n-gram textbites’, small textual segments that characterise that author’s writing, providing DNA-like chunks of identifying material
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