1,720,955 research outputs found
Evaluación del comportamiento de cultivares de arroz frente al “Entormchamiento” (Rice Stripe Necrosis Virus)
Full text linkPósterEl “Entorchamiento del Arroz” se confirmó en Argentina, en 2018. Su velocidad de dispersión es preocupante ya que una vez instalada en lotes, es imposible erradicarla. La resistencia genética es una importante herramienta de manejo. Objetivo: Evaluar el comportamiento de cultivares frente a la enfermedad.EEA Concepción del UruguayFil: Asselborn, Miriam. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concepción del Uruguay; ArgentinaFil: Ayala, Jorge Omar Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista. Agencia de Extensión Rural San Javier; ArgentinaFil: Kruger, Raúl. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes; ArgentinaFil: Pachecoy, Maria Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista. Agencia de Extensión Rural San Javier; ArgentinaFil: Pedraza, Maria Virginia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concepción del Uruguay; Argentin
Tolerancia a frío en estadios tempranos del desarrollo en arroz: caracterización fenotípica de germoplasma de origen diverso y variación alélica en genes candidatos
Full text linkTesis para obtener el grado de Magíster Scientiae en Producción Vegetal, de la Universidad Nacional de Mar del Plata, en octubre de 2011El arroz es una especie de clima templado-subtropical a subtropical susceptible a bajas temperaturas durante las etapas iniciales del desarrollo. Si bien en el mundo existen materiales tolerantes, actualmente no se dispone de materiales de este tipo adaptados a la región arrocera argentina, con los que se podría adelantar la fecha de siembra, hacer coincidir la floración con el momento de máxima radiación solar y aumentar el rendimiento. Ya se ha realizado el mapeo de la tolerancia a bajas temperaturas al estado de plántula en poblaciones segregantes y el mapeo fino de un QTL asociado al carácter. A su vez se han propuesto varios genes candidatos, entre ellos OsGSTZ1, OsGSTZ2 y OsCDPK13. En el presente trabajo se caracterizó fenotípicamente un grupo de líneas endocriadas de arroz y se analizó la variación alélica en los tres genes candidatos mencionados. Se determinó la supervivencia de plántulas y el porcentaje de germinación de 116 líneas de origen diverso (incluidos testigos tolerantes y susceptibles y líneas avanzadas del programa de mejoramiento de la EEA Corrientes-INTA) en condiciones controladas de bajas temperaturas. Como resultado, los testigos empleados tuvieron una respuesta acorde a lo esperado. Además, tanto en el estadio de plántula como en la germinación se detectaron líneas de comportamiento similar a los testigos, intermedio entre testigos tolerantes y susceptibles y más extremo, pero no se halló correlación entre ambos estadios. Para analizar la variación alélica se seleccionaron las diez líneas con respuesta más contrastante para el carácter (cinco susceptibles y cinco tolerantes) y se amplificó la región codificante con iniciadores específicos. Posteriormente se secuenciaron los productos de PCR y se analizaron las secuencias obtenidas. Para cada uno de los fragmentos se alinearon las secuencias obtenidas con las correspondientes secuencias de referencia (ADN genómico y ADNc de arroz en bases de datos públicas). Se analizó la densidad de polimorfismos de nucleótido simple (“SNPs”) e inserciones/deleciones (“indels”), y se encontró un total de 34 polimorfismos en los tres genes (28 SNPs y seis indels). Ocho SNPs y un indel separaron a las líneas según su fenotipo. Dos de los SNPs se localizaron en exones, uno se detectó en la región no traducida 3‟, y los restantes SNPs y el indel se hallaron en intrones. Para los SNPs hallados en exones se determinó la ubicación de la base polimórfica en el codón y se realizó la traducción de la región codificante a proteína para determinar el tipo de cambio producido. Únicamente uno de los SNPs (A>G), ubicado en el gen OsGSTZ2, resultó en un cambio de aminoácido (Ile>Val). La presencia de este SNP en las líneas analizadas indicaría una asociación del alelo G con la sensibilidad a bajas temperaturas. No obstante, debería verificarse si dicha asociación se mantiene en un mayor número de genotipos. Los resultados del presente estudio indican que se cuenta con amplia variabilidad para la tolerancia a frío en estadios tempranos del desarrollo en líneas de arroz adaptadas a condiciones locales, aunque es necesario determinar si la respuesta observada en condiciones controladas es reproducible a campo.Rice is a crop from tropical and subtropical areas, susceptible to low temperatures during early growth stages. Whereas there are genetic materials with cold tolerance, these have been developed for other conditions than those occurring in Argentina‟s rice
growing area, or their grain type is not suitable for the local market. If such locally adapted varieties were available, growers could anticipate sowing date, make flowering time coincide with the moment of maximum solar radiation and increase yields. Mapping of tolerance to low temperatures at the seedling stage in segregant populations and fine mapping of a QTL associated with the trait have been achieved
recently. In turn, several candidate genes have been proposed, including OsGSTZ1, OsGSTZ2 y OsCDPK13.
In this work, a group of rice inbred lines was phenotypically characterized, and allelic variation in the three candidate genes mentioned above was analyzed in a subset of such materials. Seedling survival and germination percentage of 116 materials of diverse origin (including tolerant and susceptible controls and advanced lines from EEA
Corrientes-INTA‟s breeding program) were determined under controlled, low temperature conditions. As a result, those materials used as controls responded to cold as expected. In addition, materials with behavior similar to controls, intermediate between susceptible and tolerant controls and more extreme than controls were
detected at both seedling stages and, germination but no correlation was found between stages. Those genetic materials with the most contrasting response to cold (five tolerant and
five susceptible materials) were selected to analyze allelic variation at candidate genes. The coding region of genes OsGSTZ1, OsGSTZ2 y OsCDPK13 was amplified by PCRusing specific primers. Subsequently, PCR products were sequenced and the sequences obtained were analyzed. Sequences were aligned with rice genomic DNA and full cDNA sequences, available in public databases. Density of single nucleotide polymorphisms (SNPs) and of
insertions/deletions ("indels") was assessed, and a total of 34 polymorphisms was found in the three genes (28 SNPs and six indels). Seven SNPs and an indel separated genetic materials by their phenotype (susceptible or tolerant). Two of these
SNPs were located in exons, one SNP was found in the 3‟ UTR region and the
remaining SNPs and the indel were found in introns. The location of the polymorphic base in the codon was determined for the SNPs found in exons, and the translated sequence was inspected for aminoacid changes. Only one of the SNPs (A> G) located in gene OsGSTZ2 resulted in an aminoacid change (Ile> Val). Apparently, the
presence of this SNP in the materials studied indicates an association of the G allele with sensitivity to low temperatures, although this should be examined in a larger number of genotypes. The results of the present study indicate that wide variability for cold tolerance at early growth stages in rice is available in advanced breeding materials that are adapted to local growing conditions. However, whether the response observed under a controlled environment is reproducible in field conditions remains to be ascertained.EEA CorrientesFil: Pachecoy, Maria Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes; 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
Arroz: Implicancia del peso específico de granos en la calidad de semillas
Full text linkEl tamaño y peso específico (PE) de semillas incide en su calidad y, en arroz, sus variaciones explican diferencias. Con el objeto de relacionar variables morfométricas con parámetros de calidad fi siológica, se evaluó largo, ancho, peso de 1000 semillas, poder y energía germinativa, stand y vigor de plantas en 4 cultivares de arroz fraccionados por PE. La distribución porcentual de las categorías de PE difiere entre cultivares. Las semillas oscilaron entre 9,30-10,50 mm de largo y 2,41-2,75 mm de ancho encontrándose efectos significativos del cultivar y el PE. En el peso de 1000 semillas, PAC 103 sobresalió por su mayor masa y se evidenció un gradiente según la categoría de PE. El poder germinativo, porcentaje de plantas normales, anormales y semillas no germinadas, energía germinativa y stand de plantas fueron afectados por el PE. La fracción de semillas con PE<1.14 g/cm3 presentó un peor desempeño en dichos parámetros.Size and specifi c gravity (SG) of seeds affects their quality and, in rice, these variations explain differences. In order to relate morphometric variables with physiological quality parameters, length, width, weight of 1000 seeds, germinating power and energy, plant stand and vigor were evaluated in 4 rice cultivars fractionated by SG. The percentage distribution of SG categories differs between cultivars. The seeds ranged between 9.30-10.50 mm in length and 2.41-2.75 mm in width, with significant effects of cultivar and SG. In 1000 seeds weight, PAC 103 stood out for its greater mass and a gradient was evidenced according to the SG category. Germinating power, percentage of normal and abnormal plants and ungerminated seeds, germination energy and plant stand were affected by SG. Seeds with PE <1.14 g/cm3 showed a worse performance in these parameters.EEA CorrientesFil: Gómez Ibarra, R.A. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Kruger, Raúl. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes; ArgentinaFil: Kruger, Raúl. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Pachecoy, Maria Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes; ArgentinaFil: Herber, Luciana Graciela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes; ArgentinaFil: Fontana, María Laura. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Fontana, María Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes; Argentin
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
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