1,720,955 research outputs found
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
The Spatial Ecology of Swainson\u27s Thrush (Catharus ustulatus) in the Andean Foothills of Ecuador
No full textThroughout much of the 20thcentury and beyond, migratory birds have faced rapid declines in North America. The breeding bird survey (monitoring avian population trends since the mid-1960s) and concurrent land use changes implicate habitat degradation and fragmentation as underlying causes of these declines. The Swainson’s Thrush (Catharus usutulatus) is a Nearctic-Neotropical migrant that has suffered declines of about 0.7% per year over the last 45 years and is subject to greater declines as human populations expand and suitable habitat at both the breeding and wintering grounds become altered. The breeding ground ecology of the Swainson’s Thrush(SWTH)has been extensively studied over much of the last several decades, however, the wintering ground ecology lacks similar effort. No study to date, to our knowledge, has looked at the wintering habitat use and spatial occupancy as they relate to demographics and migratory connectivity of a local wintering population of SWTH. Therefore we initiated a study that incorporated data from the winters of 2013 and 2014 on SWTH winter ecology by using point counts, vegetation surveys, radio telemetry, molecular sexing and isotopic analysis techniques at Wildsumaco Wildlife Sanctuary, Ecuador.
Point counts were set up between two forest types, primary and secondary, and they statistically differed with primary sites having larger DBH (t = -2.78, df = 22, p = 0.013), higher cover of woody plants \u3e5 m in height (t = -4.56, df = 22, p \u3c 0.001), and higher canopies (t = -3.76, df = 22, p = 0.001). The total detections of SWTH was significantly higher in secondary forest sites (W = 534, df = 22, p \u3c 0.001), with the highest detection rates in 5 of the 12 secondary stations. These five stations statistically differed from other secondary stations by exhibiting lower DBH (t = -3.49, df = 10, p = 0.007), lower canopy heights(t = -2.12, df = 10, p = 0.036), and higher tree cover (t = 1.98, df = 10, p = 0.044). SWTH densities significantly decreased over the course of the seven week surveying period (F = 6.54, df = 1, p = 0.027). Of the 86 birds caught between the 2013 and 2014 seasons, 85 of them sexed as male and 83 of them aged as young of the year (SY). An additional 27 blood samples donated to us by Kristen Ruegg from UCLA taken across a broader range of Ecuador sexed 20 of them as male. This almost completely uniform population of young males seemed to prefer secondary forest with higher amounts of small trees with low canopy heights. Since birds within this population decreased in density over the course of the field season, we suggest that this population is itinerant in behavior and possibly tracking seasonal fruit.
Radio telemetry revealed that this population of young males exhibited an extreme degree of overlap when tracked simultaneously. Up to eight birds were tracked at one time and they all occupied similar habitat space. Indeed we observed several individuals foraging in the same tree with little aggression towards conspecifics. These tracked birds also occupied relatively large areas (x̅= 2.36 ± 0.92 hectares)and had a short residency time (x̅= 17.1 ± 2.68 days). These findings corroborate the point count results, suggesting itinerant and non-territorial behavior in this wintering population. Intratropical movements are not uncommon in migratory species suggesting this non-territorial population at Wildsumaco either covers large areas to exploit seasonal resources or undergoes a mid-winter intratropical migration.
Migratory connectivity was assessed by analyzing stable hydrogen isotopes (2H) in feathers of SWTH. Precipitation 2H values correlate to the values in bird feathers; therefore this analysis is auseful approach to link the breeding and wintering grounds in some migratory birds. Feather 2H values were extremely variable indicating a broad breeding distribution among this wintering population. When these values were correlated with precipitation values in North America, we found that our birds could breed in three distinct areas stretching across the entire breeding range. This indicates weak migratory connectivity within the boreal subspecies of SWTH. Thus, habitat alteration in a local area on the wintering grounds can affect populations from across the breeding grounds, but these losses may be more difficult to detect.
The majority of future conservation efforts rely in part on researchers’ ability to convey useful information from their studies to governmental and public stakeholders. By creating awareness within the local communities, partnerships can originate that might generate necessary support and funding for future projects. These projects should focus on obtaining as much information on the full annual cycle of declining migratory birds, concentrating on the wintering grounds. Efforts directed at this phase of the annual cycle will likely have the greatest conservation impact for migratory birds, especially given the proportional total area of the wintering ranges compared to the breeding ranges of most Nearctic-Neotropical migratory species
The spatial ecology of Swainson's thrush (Catharus ustulatus) in the Andean foothills of Ecuador
Get PDFThroughout much of the 20thcentury and beyond, migratory birds have faced rapid declines in North America. The breeding bird survey (monitoring avian population trends since the mid-1960s) and concurrent land use changes implicate habitat degradation and fragmentation as underlying causes of these declines. The Swainson's Thrush (Catharus usutulatus) is a Nearctic-Neotropical migrant that has suffered declines of about 0.7% per year over the last 45 years and is subject to greater declines as human populations expand and suitable habitat at both the breeding and wintering grounds become altered. The breeding ground ecology of the Swainson's Thrush (SWTH) has been extensively studied over much of the last several decades, however, the wintering ground ecology lacks similar effort. No study to date, to our knowledge, has looked at the wintering habitat use and spatial occupancy as they relate to demographics and migratory connectivity of a local wintering population of SWTH. Therefore we initiated a study that incorporated data from the winters of 2013 and 2014 on SWTH winter ecology by using point counts, vegetation surveys, radio telemetry, molecular sexing and isotopic analysis techniques at Wildsumaco Wildlife Sanctuary, Ecuador.
Point counts were set up between two forest types, primary and secondary, and they statistically differed with primary sites having larger DBH (t = -2.78, df = 22, p = 0.013), higher cover of woody plants >5 m in height (t = -4.56, df = 22, p < 0.001), and higher canopies (t = -3.76, df = 22, p = 0.001). The total detections of SWTH was significantly higher in secondary forest sites (W = 534, df = 22, p < 0.001), with the highest detection rates in 5 of the 12 secondary stations. These five stations statistically differed from other secondary stations by exhibiting lower DBH (t = -3.49, df = 10, p = 0.007), lower canopy heights(t = -2.12, df = 10, p = 0.036), and higher tree cover (t = 1.98, df = 10, p = 0.044). SWTH densities significantly decreased over the course of the seven week surveying period (F = 6.54, df = 1, p = 0.027). Of the 86 birds caught between the 2013 and 2014 seasons, 85 of them sexed as male and 83 of them aged as young of the year (SY). An additional 27 blood samples donated to us by Kristen Ruegg from UCLA taken across a broader range of Ecuador sexed 20 of them as male. This almost completely uniform population of young males seemed to prefer secondary forest with higher amounts of small trees with low canopy heights. Since birds within this population decreased in density over the course of the field season, we suggest that this population is itinerant in behavior and possibly tracking seasonal fruit.
Radio telemetry revealed that this population of young males exhibited an extreme degree of overlap when tracked simultaneously. Up to eight birds were tracked at one time and they all occupied similar habitat space. Indeed we observed several individuals foraging in the same tree with little aggression towards conspecifics. These tracked birds also occupied relatively large areas (x̅= 2.36 ± 0.92 hectares)and had a short residency time (x̅= 17.1 ± 2.68 days). These findings corroborate the point count results, suggesting itinerant and non-territorial behavior in this wintering population. Intratropical movements are not uncommon in migratory species suggesting this non-territorial population at Wildsumaco either covers large areas to exploit seasonal resources or undergoes a mid-winter intratropical migration.
Migratory connectivity was assessed by analyzing stable hydrogen isotopes (2H) in feathers of SWTH. Precipitation 2H values correlate to the values in bird feathers; therefore this analysis is auseful approach to link the breeding and wintering grounds in some migratory birds. Feather 2H values were extremely variable indicating a broad breeding distribution among this wintering population. When these values were correlated with precipitation values in North America, we found that our birds could breed in three distinct areas stretching across the entire breeding range. This indicates weak migratory connectivity within the boreal subspecies of SWTH. Thus, habitat alteration in a local area on the wintering grounds can affect populations from across the breeding grounds, but these losses may be more difficult to detect.
The majority of future conservation efforts rely in part on researchers' ability to convey useful information from their studies to governmental and public stakeholders. By creating awareness within the local communities, partnerships can originate that might generate necessary support and funding for future projects. These projects should focus on obtaining as much information on the full annual cycle of declining migratory birds, concentrating on the wintering grounds. Efforts directed at this phase of the annual cycle will likely have the greatest conservation impact for migratory birds, especially given the proportional total area of the wintering ranges compared to the breeding ranges of most Nearctic-Neotropical migratory species.Electronic Thesis or Dissertatio
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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