1,721,197 research outputs found
Data and R code for replicating results of the paper: Mechanisms influencing network topology in plant-hummingbird pollination networks
No full textcommunityINFO: Contains flower abundance data for each month, year, and transect, along with detailed geographical information (coordinates, elevation, and site identity). (See metadata file for variable descriptions.)data_all: Contains hummingbird–plant interaction data, including the identity of both species, number of visits, and trait information for each partner. Each record corresponds to a specific sampling event at a given site and time, with detailed geographical and observational metadata (e.g., coordinates, sampling duration, elevation). (See metadata file for variable descriptions.)genus_list: A list of bird genera and their corresponding taxonomic families. (See metadata file for variable descriptions.)Megatree: A megaphylogeny of birds provided by the U.phylomaker R package.
https://doi.org/10.1016/j.pld.2022.12.007phylo_hb & phylo_plant: These datasets provide taxonomic classifications for all species included in the study. phylo_hb classifies each hummingbird species into its corresponding genus and family, while phylo_plant does the same for plant species.RData contains five data frames with the original data required to conduct the analyses. The data are a subset from the forthcoming data paper: "Plant-hummingbird interactions, floral abundance, and floral traits for three altitudinal gradients in the Americas."Peer reviewe
Human disturbance and birds of the Northeast: What makes some species decline, while others are just fine?
No full text149 pg.Mounting evidence reveals the negative impacts of human activities on wildlife populations. However, studies investigating species' responses to human disturbance often rely on patterns of species' richness or abundance, and may not reflect underlying demographic processes. Is there evidence across geographic regions that humans are causing marked changes in species' survival, reproduction, and population growth? Do species' traits influence vulnerability? Can existing theories of ecology serve to predict or explain observable responses to human disturbance? I examined evidence of effects of human disturbance on populations of 24 breeding bird species across the northeastern United States. Based on reported literature and theoretical expectations, I developed hypotheses about effects of human disturbance on demographic parameters. I first tested the hypothesis that human disturbance negatively impacts survival, reproduction, and population growth across species, by determining the importance of human disturbance and the direction of its effect in predicting demographic parameters. I found support for negative impacts of humans on bird populations, but not consistently across species. Next, I tested hypotheses about characteristics that make species vulnerable to human disturbance, by comparing their relationship to each other and the direction of their effect on demographic parameters in the absence and presence of disturbance. Some expected characteristics revealed vulnerability to human disturbance, but the effect was not always consistent across demographic parameters. Lastly, I tested for evidence of a cost of reproduction on survival or future reproduction across species, and asked if human disturbance enhanced costs. A cost of reproduction expected by life history theory was evident across species, but not consistently across different levels of human disturbance. While populations of numerous bird species are declining locally and globally, the extent to which effects of human disturbance are species- specific versus generalizable is not well understood. Mitigating the problem is limited without multi-species analyses of the demographic parameters driving persistence. My results contribute to the body of research measuring human impacts on wildlife populations, demonstrate the value of theoretical and empirical knowledge for predicting and understanding species' responses, and underscore the importance of long-term, large-scale population monitoring programs to collect data integral to addressing these questions.Advisor(s): Graham, Catherine H. Committee Member(s): Ak?¼akaya, H. Resit ; Levinton, Jeffrey S; Pidgeon, Anna M.Advisor(s): Graham, Catherine H. Committee Member(s): Ak?¼akaya, H. Resit ; Levinton, Jeffrey S; Pidgeon, Anna M.Stony Brook University Libraries. SBU Graduate School in Department of Ecology and Evolution. Charles Taber (Dean of Graduate School)
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 Effect of Detergents on the Proteinase K Resistance of PrPSc in Different Transmissible Spongiform Encephalopathies (TSEs)
No full textThe Effect of Detergents on the Proteinase K Resistance of PrPSc in Different Transmissible Spongiform Encephalopathies (TSEs)
No full textDispelling 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
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