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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
Heavy metal concentrations in the edible tissues of some commercial fishes caught along the Eastern Black Sea coast of Turkey and the health risk assessment
No full textConcentrations of some metals were determined in muscle tissue of five marine fish species (Engraulis encrasicolus, Sarda sarda, Mullus barbatus, Trachurus mediterraneus, and Merlangius merlangus) caught from the Eastern Black Sea coast of Turkey in 2017. Heavy metals were analyzed by using inductively coupled plasma-optical emission spectrometry after the muscle tissues of fish were digested by acids. The metal accumulation differences between species were investigated statistically. The levels of aluminum, cadmium, chromium, copper, iron, manganese, lead, and zinc in the muscles of fish were 3.27, 0.12, 0.27, 2.04, 9.97, 1.00, 0.95, and 10.65 mu g/g, respectively. The highest levels of aluminum, cadmium, chromium, and manganese were detected in E. encrasicolus; the highest levels of lead and zinc were accumulated in T. mediterraneus and the highest concentration of iron and copper was found in S. sarda. The average lead concentration values were found to be above the limit values determined by national and international standards due to anthropogenic inputs such as mining activities and agricultural wastes. In addition, potential risks associated with human consumption were evaluated using quality indices such as estimated daily intake and target hazard ratio. According to these indexes, a potential risk in terms of human health has not been identified due to consuming fish tissues
Determination of the trace elements levels of some streams and terrestrial input into Black Sea with stable carbon and nitrogen isotope ratios in the Eastern Black Sea catchment
No full textBu araştırmada Doğu Karadeniz Havzası akarsularının fiziko-kimyasal su kalitesi, suda, askıda katı maddede ve sedimentte eser element düzeyleri ile Fırtına Deresi'nin Karadeniz'e taşımış olduğu karasal girdilerinin duraylı karbon ve azot izotop yöntemi kullanılarak belirlenmiştir. İncelenen 8 akarsuyun yıllık ortalama su sıcaklığı 14,22±0,53 °C, pH'sı 7,62±0,06, elektriksel iletkenlik değeri 158,63±8,84 µS/cm, çözünmüş oksijeni 10,38±0,13 mg/L ve askıda katı madde miktarı 68,36 mg/L olarak ölçülmüştür. Ayrıca NO2-N 0,016±0,005 mg/L, NO3-N 0,340±0,026 mg/L, o-PO4-P 0,388±0,06 mg/L ve SO4 10,46±0,95 mg/L olarak belirlenmiştir. Bunların yanında Doğu Karadeniz Havzasında örneklemesi yapılan akarsuların suyunda, sedimentinde ve askıda katı maddesinde incelenen eser elementlerde mevsimsel değişimler olmasına rağmen önemli bir ağır metal kirliliğiyle karşılaşılmamıştır. Fırtına Deresinin denizel ortama karasal girdilerinin hangi oranlarda olduğuna yönelik yapılan çalışmada, duraylı karbon ve azot izotopik işaretleri Nisan ayında karasal sedimentin denizel sedimente katkısı ortalama % 47 iken denizel POM'a karasal POM'un katkısı % 53 olarak belirlenmiştir. Ekim ayında ise denizel sedimente; karasal sediment % 32, karasal POM % 32 ve denizel POM ise % 36 oranında katkı sağladığı tespit edilmiştir. In this study, physico-chemical water quality parameters of the streams and trace element concentration in water, suspended solid matter and sediment of some streams in Eastern Black Sea Catchment were determined. Also, terrestrial input carried into Black Sea by Fırtına Stream was identified using stable carbon and nitrogen isotope analysis. The annual means of parameters for all streams featured in this study were 14.22 °C, 7.62, 158.63 µS/cm, 10.38 mg/L for temperature, pH, electrical conductivity, and dissolved oxygen, respectively. On the other hand, the amount of suspended solid matter (SSM) was 68.36 mg/L, NO2- N was 0.016 mg/L, NO3-N was 0.340 mg/L, o-PO4-P levels were 0.388 mg/L, and the level of SO4 concentration was 10.46 mg/L. In addition, there was no significant heavy metal pollution measured in the sampled streams of Black Sea Catchment despite the seasonal changes in water, sediment and SSM. The stable carbon and nitrogen isotopical signiture showed that terrestrial contribution to the marine sediment was % 53 in April, 32 % in October
Distribution of toxic and trace metals in fish from the Black Sea: Implications for human health risks
Get PDFThis study focused on the investigation of toxic and trace metal levels in fish caught from the Black Sea, which is facing pollution threats from various human activities. It also aimed to assess the potential health risks associated with consuming fish and contribute to the development of strategies for sustainable fisheries management. Metal presence was observed in the muscle tissues of four commercially consumed fish species (anchovy, whiting, horse mackerel and red mullet) from nine different stations in the Black Sea. Among the metals, the highest average concentration was observed for aluminium (Al) in anchovy and the lowest concentration for cadmium (Cd) in whiting. However, the levels were generally below the maximum allowable limits recommended by the FAO, WHO, EC, and Turkish Food Codex. The study results showed that metal concentrations in the analyzed fish species did not pose significant non-carcinogenic health risks to consumers. Although research findings show that some fish species studied from the Black Sea exhibit high metal levels, the concentrations of toxic and trace elements are generally within acceptable thresholds for safe fish consumption. The findings of this study are thought to help stakeholders develop strategies for environmental protection and sustainable fisheries management in the region
Seasonal variation of trace elements and stable isotope (delta C-13 and delta N-15) values of commercial marine fish from the black sea and human health risk assessment
No full textThe purpose of this study is to examine changes in stable carbon and nitrogen isotope ratios, to determine the levels of metals (aluminum, copper, iron, manganese, lead, and zinc), and to assess the health risks associated with consumption of the most consumed pelagic and demersal fish species in Turkey. Trachurus mediterraneus, Mullus barbatus, and Merlangius merlangus were seasonally caught from the Eastern Black Sea in 2020. Concentrations of heavy metals in fish muscle tissues were measured using Inductively Coupled Plasma-Optical Emission Spectroscopy whereas stable isotope analysis was performed using Isotope Ratio Mass Spectrometer. The detected levels of metals studied in all fish species except lead were below the determined limits of national and international standards. In addition, the carcinogenic risk index was considered significant in all fish species. Considering the principal components analysis results, Cu and Pb may have originated from similar sources. No significant difference in metal content and stable isotope rates was observed between different species of fish. Also, target hazard quotient values were found below 1 in all species, which means that the consumption of the studied fish species does not pose a health risk
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