1,720,955 research outputs found
Studi keanekaragaman diatom epilitik serta potensinya sebagai bioindikator kualitas perairan sungai di Coban Tarzan Kabupaten Malang
Get PDFAir selalu menjadi kebutuhan penting dalam memenuhi segala aspek kehidupan bagi semua makhluk hidup. Keberadaan sumber daya perairan harus didukung dengan kuantitas yang tercukupi serta kualitas yang baik. Salah satu sumber daya perairan yang sering dimanfaatkan oleh makhluk hidup adalah sungai, terutama aliran sungai yang berasal dari air terjun (coban). Tujuan penelitian ini untuk mengetahui keanekaragaman jenis diatom epilitik serta potensinya sebagai organisme indikator penentu kualitas perairan sungai di Coban Tarzan Kabupaten Malang. Pengambilan sampel diatom epilitik dilakukan dengan metode terpilih (purposive sampling) pada tiga stasiun di perairan sungai Coban Tarzan. Sampel diatom epilitik diambil dari substrat batuan yang terendam air dan tidak lebih dari kedalaman 20 cm. Parameter yang diamati dan diukur antara lain Kepadatan (K), Indeks Keanekaragaman Shannon Wiener (H’), Indeks Dominansi Simpson (C) dan Indeks Tropik Diatom Epilitik. Hasil pengamatan menunjukkan bahwa kepadatan total diatom epilitik yang ditemukan di Coban Tarzan selama penelitian adalah 152.669 ind/cm2 , yang terdiri delapan genus (Amphora, Cocconeis, Cymbella, Fragilaria, Gomphonema, Navicula, Nitzschia dan Rhoicosphenia). Sementara itu nilai H’ diatom epilitik di sungai Coban Tarzan menunjukkan tingkat keanekaragaman yang sedang (H’=1,52), sedangkan untuk nilai C menunjukkan tidak ada spesies diatom epilitik yang mendominasi di perairan tersebut (C=0,25). Hasil indeks tropik diatom epilitik menunjukkan perairan sungai Coban Tarzan tergolong memiliki kualitas perairan dengan kategori sedang (mesotrofik)
The Epilithic Diatom Community as a Bioindicator of water quality Brangkal Subwatershed in the Mojokerto Area
Get PDFDiatoms are widely used as bioindicators of water quality because of their short life cycle and sensitivity to changes of environmental conditions in waters.  One type of diatom that is used as a bioindicator is an epilithic diatom. Epilithic diatoms are one of the diatom microalgae communities attached to rock, so they are difficult to be carried away by currents. This study aimed to determine the type, composition, abundance, diversity, and dominance of epilithic diatoms found in the waters of the Brangkal subwatershed, and to determine the quality of water in the Brangkal subwatershed based on the epilithic diatom tropic index. Epilithic diatom samples were taken from 4 stations in the Brangkal subwatershed, Mojokerto Regency at the beginning of the dry season (July-August). The analysis carried out includes abundance, diversity index, dominance index, and Diatom Trophic Index (TDI). Based on the results of the study, 17 genera of epilithic diatoms were found, with the highest abundance of epilithic diatoms, including Navicula, Cocconeis, Nitszchia, and Gomphonema. The diversity index of all stations was in the medium category, with a value between 1.206 to 1.882. The lowest dominance index at station 1 was 0.167 and the highest was at station 4 with 0.373. In addition, the observed water quality is based on the Diatom Trophic Index (TDI), stations 1 to 3 are in a good category, and stations 4 are in a bad category.Â
The epilithic diatom community as a bioindicator of water quality Brangkal subwatershed in the Mojokerto area
Get PDFDiatoms are widely used as bioindicators of water quality because of their short life cycle and sensitivity to changes of environmental conditions in waters. One type of diatom that is used as a bioindicator is an epilithic diatom. Epilithic diatoms are one of the diatom microalgae communities attached to rock, so they are difficult to be carried away by currents. This study aimed to determine the type, composition, abundance, diversity, and dominance of epilithic diatoms found in the waters of the Brangkal subwatershed, and to determine the quality of water in the Brangkal subwatershed based on the epilithic diatom tropic index. Epilithic diatom samples were taken from 4 stations in the Brangkal subwatershed, Mojokerto Regency at the beginning of the dry season (July-August). The analysis carried out includes abundance, diversity index, dominance index, and Diatom Trophic Index (TDI). Based on the results of the study, 17 genera of epilithic diatoms were found, with the highest abundance of epilithic diatoms, including Navicula, Cocconeis, Nitszchia, and Gomphonema. The diversity index of all stations was in the medium category, with a value between 1.206 to 1.882. The lowest dominance index at station 1 was 0.167 and the highest was at station 4 with 0.373. In addition, the observed water quality is based on the Diatom Trophic Index (TDI), stations 1 to 3 are in a good category, and stations 4 are in a bad category
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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