1,721,017 research outputs found
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
Evaluation of Physiological Characters and Yield of F2 Rice (Oryza sativa L.) Derived from Crosses of Mercury
No full textMercury (Hg) contamination in agricultural land is a major constraint in rice
cultivation as it negatively affects plant physiological performance and yield. This
study aimed to evaluate the physiological characteristics and yield of F2 rice (Oryza
sativa L.) derived from crosses of mercury-tolerant parental lines. The research was
conducted at the Experimental Field of the Faculty of Agriculture, Universitas
Sumatera Utara, Medan, in April 2025. The plant materials consisted of ten F2
genotypes along with their reciprocal crosses derived from five rice varieties,
namely IF-16, IR-64, Inpari-32, Cakrabuana, and Siganteng. The planting medium
was topsoil treated with 15 ppm mercury to simulate heavy metal stress conditions.
Observed parameters included chlorophyll content, stomatal density, leaf area,
fresh and dry weight of shoots and roots, and yield per plant. The results showed
significant differences among several genotypes and their reciprocals in most
physiological and yield parameters under mercury stress. Certain cross
combinations exhibited better physiological performance and higher yield,
indicating the inheritance of mercury tolerance traits from the parental lines.
Therefore, F2 rice genotypes derived from mercury-tolerant parents have potential
as selection materials in breeding programs aimed at developing mercury-tolerant
rice varieties.72 PagesSkripsi Sarjan
The Effect of Thidiazuron (TDZ) and Casein Hydrolysate Combination on the Shoot Multiplication of Barangan Red Bananas (Musa acuminata Linn.) In Vitro
No full textThe aim of research was to determine the effect and see the interaction
between the concentration of Thidiazuron (TDZ) and Casein Hydrolysate on the
multiplication of barangan red banana buds (Musa acuminata Linn) in vitro. This
research was conducted at the Tissue Culture Laboratory, Alifa Agricultural
Research Center (ALIFA-ARC) Medan. This research will be conducted from
November 2023 to February 2024. This study used the Complete Randomized
Design (CRD) method with two factors. The first factor is the concentration of
casein hydrolysate (C): C0 (0 mg / l), C1 (100 mg / l), C2 (200 mg / l) and C3 (300
mg / l). The second factor is the concentration of thidiazuron (T): T0 (0 mg / l), T1
(0.2 mg / l), T2 (0.4 mg / l) and T3 (0.6 mg / l). The observed variables were the
percentage of live explants, the number of shoots, the length of shoots, the number
of roots, and the length of roots. The results showed that thidiazuron treatment
had a significant effect on shoot multiplication. Casein hydrolysate treatment had
no significant effect on shoot multiplication. The combination of thidiazuron and
casein hydrolysate treatment had no significant effect on shoot multiplication62 PagesSkripsi Sarjan
Sxreening of Mercury Tolerant Rice Varieties (Oryza sativa L.) as a Genetic Source for Mercury Tolerant Rice Assembly in Madina District
No full textThe high level of mercury in wastewater comes from unlicensed gold mining activities in Mandailing Natal Regency, which causes rice plants planted in paddy fields to be contaminated through irrigation using groundwater containing heavy metals. In addition to impacting the environment, mercury was also very dangerous for human health. This study aims to determine the effect of mercury on rice plant growth, to determine differences in tolerance between varieties to mercury stress, and to determine the interaction between varieties and mercury in the early vegetative growth phase. This research was conducted in the Green House, Plant Disease Laboratory, and Plant Biotechnology Laboratory, Faculty of Agriculture, University of North Sumatra, from July 2023 to May 2024. This study used a factorial Randomized Block Design with 2 factors. The first factor were 8 paddy rice varieties and the second factor were the dose of mercury including: M0 (control) and M1 (1 ppm mercury). The results showed that the variety treatment was significantly different on the parameters of plant height and Hg levels in the roots of rice plants, the mercury dose treatment significantly affected the parameters of root length and Hg levels in the leaves of rice plants, there was no interaction between varieties and mercury doses on all observed parameters. There are Sigupai and Cakra Buana varieties that have tolerant properties based on agromorphology and DNA analysis.69 PagesSkripsi Sarjan
Effect of Cytokinins and GA3 on In Vitro Sprout Growth of Potato Plants (Solanum tuberosum L.)
No full textPotatoes are one of the important food crops in the world and serve as a source of carbohydrates. However, the provision of quality potato seeds still faces various problems, especially related to pest and disease attacks. Tissue culture techniques are an alternative in the propagation of Granola Variety potatoes. This study aims to determine the effect of the type and concentration of cytokinin and gibberellic acid (GA3) on the growth of potato shoots (Solanum tuberosum L.) in vitro. The research was carried out at the Alifa Agricultural Research Center (ALIFA-ARC) Network Culture Laboratory in Medan, from October to December 2024. The method used was a Completely Randomized Design (CRD) method with two factorials. The first factor was cytokinin concentration (TDZ and BAP), and the second factor was GA3 concentration. The parameters observed included the percentage of live explants, the percentage of contaminated explants, the time of bud emergence, the number of shoots, the height of the shoots, and the number of roots. The results showed that the application of cytokinin and GA3 had no significant effect on the percentage of live explants, contamination, and bud height, but the application of cytokinin had a significant effect on the time of emergence of buds at the best treatment of S5 (BAP 1.5 mg/l). The interaction of cytokinin and GA3 had a significant effect on the number of shoots and the number of roots with the best treatments, namely S3G0 (TDZ 4.5 mg/l + GA3 0 mg/l) and S5G2 treatment (BAP 1.5 mg/l + GA3 0.3 mg/l).70 PagesSkripsi Sarjan
Growth and Production of Several Varieties of Lowland Rice (Oryza sativa L.) on Sharing Types of Organic Fertilizer in Batu Bara Regency
No full textThis research aims to determine the growth and production of several varieties of lowland rice (Oryza sativa L.) on various types of organic fertilizer in Batu Bara district. This research was carried out in Bangun Sari Village, Datuk Tanah Datar District, Batu Bara Regency with an altitude of ±9 meters above sea level from February to May 2024. This research used a Split Plot Design (RPT) using two factors. The first factor is a combination of fertilization consisting of No Manure + Farmer's Habitual Dose of Inorganic Fertilizer, Recommended Dose of Inorganic Fertilizer, 30 ton/ha of cow manure+ Farmer's Habitual Dose of Inorganic Fertilizer, 30 ton/ha of Chicken Manure+ Farmer's Habitual Dose of Inorganic Fertilizer and Fertilizer Goat Cage 30 tons/ha+ Inorganic Fertilizer, Farmer's Habitual Dosage. The second factor is lowland rice varieties consisting of Ciherang, Inpari 32, Mekongga and Mapan-05. The parameters observed were plant height (cm), number of tillers, number of productive tillers, panicle length (cm), number of grains per panicle (grain), weight of 1000 grains, number of filled grains, number of empty grains, weight of grain per sample plant, weight. Grain Per Plot, Production Per Ha.96 PagesSkripsi Sarjan
Growth and Production of Several Varieties of Lowland Rice (Oryza sativa L.) on Sharing Types of Organic Fertilizer in Batu Bara Regency
No full textThis research aims to determine the growth and production of several varieties of lowland rice (Oryza sativa L.) on various types of organic fertilizer in Batu Bara district. This research was carried out in Bangun Sari Village, Datuk Tanah Datar District, Batu Bara Regency with an altitude of ±9 meters above sea level from February to May 2024. This research used a Split Plot Design (RPT) using two factors. The first factor is a combination of fertilization consisting of No Manure + Farmer's Habitual Dose of Inorganic Fertilizer, Recommended Dose of Inorganic Fertilizer, 30 ton/ha of cow manure+ Farmer's Habitual Dose of Inorganic Fertilizer, 30 ton/ha of Chicken Manure+ Farmer's Habitual Dose of Inorganic Fertilizer and Fertilizer Goat Cage 30 tons/ha+ Inorganic Fertilizer, Farmer's Habitual Dosage. The second factor is lowland rice varieties consisting of Ciherang, Inpari 32, Mekongga and Mapan-05. The parameters observed were plant height (cm), number of tillers, number of productive tillers, panicle length (cm), number of grains per panicle (grain), weight of 1000 grains, number of filled grains, number of empty grains, weight of grain per sample plant, weight. Grain Per Plot, Production Per Ha.96 PagesSkripsi Sarjan
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