1,720,954 research outputs found
Evaluación de las áreas bajo riego afectadas por salinidad y/o sodicidad en Argentina
Full text linkLa obra muestra la superficie actual bajo riego en Argentina por diferentes metodologías de aplicación, el grado de afectación de los suelos regados por sales y sodio. Incluye información de las regiones áridas, semiáridas y de la Pampa Húmeda, donde el riego ha manifestado su mayor expansión. Realizada en convenio INTA - FAO.EEA Hilario AscasubiFil: Sanchez, Ramon Mauricio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Dunel Guerra, Luciana Gisele. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Scherger, Maira. Asesora privada; Argentin
Germination and emergence of corn (Zea mays, L) as a function of soil physical parameters
Full text linkTesis para obtener el grado de Magister Scientiae en Soil Science, de la Oregon State University, en diciembre de 1988Rates of germination and emergence of corn were measured as influenced by soil physical parameters using blotter paper and a sandy loam soil as growth media. The corn seeds used were a hybrid of Funk's (DJ7xLH93). Experimental conditions were soil temperature of 20°C, 25°C, 30°C, and 35°C, soil water potential of -33, -100, -500, and -1000 kPa, soil bulk density 1.29 and 1.36 Mg/m³ and seeding depth of 3 and 7 cm. For the germination experiment seeds were put in contact with polyethylene glycol at solution concentrations to produce the desired water potentials. Treatment temperatures were maintained in a growth chamber and germination was evaluated every twelve hours. The number of hours required to obtain 50 and 80% germination was significantly increased by lowering either temperature or water potential. Although significant interactions were measured, temperature and water potential affected germination in different ways. Time to attain 80% of germination decreased as temperature increased until the optimum of 30°C was reached. Decreased osmotic potential levels progressively delayed and reduced germination. Time to germination increased greatly below -500 kPa. For emergence experiments seeds were planted in soil packed in covered containers which were placed in a growth chamber. Effects of soil temperature, soil water potential, bulk density, and seeding depth were evaluated. Bulk densities of 1.29 and 1.36 Mg/m³ , were achieved by no compaction and compaction. The two seeding depth were 3 and 7 cm. Time needed for emergence was influenced by soil temperature more than by any other variable. The time for emergence decreased progressively with lowering of soil water potential, lowering temperature or with increase in seeding depth. No significant differences resulted from increasing bulk density. In both the germination and emergence experiments, changes in temperature were more important than changes in water potential at high water potential. However this relation was reversed at water potentials lower than -500 kPa, where changes in water potential were more important than changes in temperature. The minimum time for both germination and emergence occurred at 30°C, at all water potentials. Effect of seeding depth was more important than effect of bulk density for time to emergence. Increases in time were between 20-30% as the seeding depth increased from 3 to 7 cm. Compaction began to limit seedling emergence at 1.44 Mg/m³.EEA Hilario AscasubiFil: Sanchez, Ramon Mauricio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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