1,721,000 research outputs found
Are trapping data suited for home-range estimation?
No full textModern home-range estimation typically relies on data derived from expensive radio- or GPS-tracking. Although trapping represents a low-cost alternative to telemetry, there lacks an evaluation of the performance of home-range estimators on trap-derived data. Using simulated data, we evaluate three variables reflecting the key trade-offs ecologists face when designing a trapping study: 1) the number of observations obtained per individual, 2) the trap density, and 3) the proportion of the home range falling inside the trapping area. We compare the performance of five home-range estimators (MCP, LoCoH, KDE, AKDE, bicubic interpolation). We further explore the potential benefits of combining these estimators with asymptotic models, which leverage the saturating behavior of changes in the estimated home-range area as the number of observations increases to improve accuracy, as well as different data ordering procedures. We then quantified the bias in home-range size under the different scenarios investigated. The number of observations and the proportion of the home range within the trapping grid were the most important predictors of the accuracy and the precision of home-range estimates. The use of asymptotic models helped obtain accurate estimates at smaller sample sizes, while distance-ordering improved the precision and asymptotic consistency of estimates. While AKDE was the best-performing estimator under most conditions evaluated, bicubic interpolation was a viable alternative under common real-world conditions of low trap density and area covered. A case study using empirical data from white-tailed deer in Florida and another from jaguars in Belize demonstrated support for the findings of our simulation results. Although researchers with trap data often overlook home-range estimation, our results indicate that these data have the capacity to yield accurate estimates of home-range size. Trapping data can therefore lower the economic costs of home-range analysis, potentially enlarging the span of species, researchers and questions studied in ecology and conservation.All data can be opened with R. All R scripts to create and analyze the data can be found at https://github.com/llsociasmartinez/home-range-trapping-data.Funding provided by: Natural Sciences and Engineering Research Council of CanadaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000038Award Number: RGPIN-2021-02758Using an I.I.D. movement model, we simulated captures in different trapping conditions and compared the home range size obtained with different methods. We analyzed real-world trapping data for white-tailed deer (Florida) and jaguars (Belize) from publicly available repositories and compared the home range sizes obtained with those predicted based on our simulations
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
Navigating coexistence : examining the effects of winter recreation on southern mountain caribou space use and resource selection in shared ecosystems
No full textSouthern mountain caribou (Rangifer tarandus caribou, hereafter SMC) are a federally listed species at risk (threatened) that inhabit deep snow and mountainous environments in parts of British Columbia and Alberta. Winter recreationists seek out these same habitats, with heli-skiing being the predominant recreation that overlaps both spatially and temporally with SMC on their late-winter ranges. In 2020, COVID-19-induced travel restrictions severely limited heli-skiing over the winter of 2020/2021, creating a year where SMC was not exposed to this type of recreation. In this thesis I used data from GPS-collared SMC to compare the movement ecology of SMC during this ‘anthropause’ year against three winters of normal heli-ski operations to elucidate the effect of heli-skiing on SMC space use. During the anthropause year, SMC expanded their home ranges by 80 – 120% as compared to years of normal heli-ski operations, but movement rates and resource selection did not change. This change in home range size without an associated change in the available resource quality and abundance may indicate that SMC are restricted in their ability to obtain nutrients under normal heli-ski operations, potentially impacting individual fitness and survival.
I used these home ranges to estimate 3rd order resource selection, accounting for differences among individuals and sub-populations. Resource selection by SMC was predominantly explained by elevation, and slope, but forest crown closure and forest age also help to explain their selection. I also created a resource selection function for heli-skiing, using openly available, anonymized human-movement data from Strava to understand the underlying features selected for by heli-skiers. Heli-skiers primarily select for moderate slopes, mid- to high elevations and aspects other than south. I projected and compared these two resource selection functions to identify where heli-skiing and SMC late-winter range likely overlap. Southern mountain caribou and heli-skiing select for similar terrain attributes, but heli-skiing can exploit a wider range of terrain features, thus a large proportion of the study area is suitable for heli-skiing, but is not also highly suitable SMC late-winter habitat. While there appears to be a high degree of overlap on the landscape, careful management of heli-skiing may reduce those interactions with SMC that are causing reductions in home range size. Better information on the location of skiing and helicopter flight paths can improve the understanding of fine-scale effects on this vulnerable species.Science, Irving K. Barber Faculty of (Okanagan)Biology, Department of (Okanagan)Graduat
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
Mapping the spatial distribution of terrestrial microplastics
No full textPlastic’s versatile nature and ability to be rapidly and inexpensively manufactured have resulted in mass production since the 1960s. Microplastics have become so pervasive within the environment that they have been detected in the most remote environments – even in areas where human activity is nearly absent. Despite the widespread distribution of plastic pollution and the fact that microplastics likely impact soil bulk density, microbial communities, plant growth, and biogeochemical and hydraulic cycles, the implications of terrestrial microplastics within soil environments remain largely unknown. Additionally, the impacts of microplastic pollution on soil is not uniform as the shape, size, and composition of polymers will affect each ecosystem differently. Existing knowledge is also limited to point-sampling, with no ability to interpolate concentrations at unsampled locations. This thesis aims to enhance our current understanding of what factors influence microplastics concentrations in soil, as well as how microplastic concentrations change within the soils of British Columbia’s range land. To this end, I compile existing data on the occurrence of microplastics in terrestrial soils. I then use a geostatistical technique known as regression-Kriging to model the drivers of terrestrial microplastics pollution and make predictions about the expected concentrations at unsampled locations. I found that microplastic concentrations tended to increase when moving towards a value of 1 on the human footprint index (HFI), while they tended to decrease at greater soil depths and at higher elevations. Additionally, I collect soil samples across nine different locations in British Columbia and isolate the microplastics found in eight of these samples by carrying out an 18-day long protocol. Within these samples, I found there was an average of 4.23 x 10⁻⁴ ± 2.66 x 10⁻⁴ items·kg⁻¹ (mean ± SE) of plastic in soils for particles greater than 500-µm. These results provide a framework for both sampling and isolating microplastics from soil and contribute to our understanding of how terrestrial microplastics are distributed across terrestrial environments.Science, Irving K. Barber Faculty of (Okanagan)Biology, Department of (Okanagan)Graduat
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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