1,721,004 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Evaluating wetland extent trends using remote sensing: case studies in the Canadian Rockies
No full textMountainous wetlands provide critical ecosystem services, but their sustainability is increasingly threatened by climate change impacts on river flow, runoff regimes, and landscape dynamics. The main objective of this thesis is to investigate how wetland hydrology and land cover in two mountainous regions, the Upper Columbia floodplain in British Columbia and the Eastern Slopes of Alberta (ES), are changing over time and how they could react under future climate scenarios. The specific aims of this thesis are to: 1) Evaluate historical and projected changes in wetland land cover and hydrology in the Upper Columbia River floodplain (1984–2040); 2) Apply and expand these methods to the ES (1984–2023); 3) Quantify open water evaporation relative to forest ecosystem evapotranspiration volumes, and assess seasonal variations between the snowmelt- and rainfall-dominated periods.
Results on Objective 1 indicate that from 1984 to 2022 the Upper Columbia floodplain has already undergone significant hydrological and ecological changes. Peak river discharge now occurs eleven days earlier and with shorter duration, so generating greater peak flows over a shorter period. These shifts have matched a drying trend in wetland habitats and a transition to woody and shrubby vegetation. Under both RCP 4.5 and RCP 8.5, projected data (2020s–2040s) show a continuous reduction in late-summer open water areas; the seasonal peak shifts earlier into spring (April to mid-May). Applying a similar analytical approach to the ES in Objective 2 revealed both parallel and contrasting trends. In the snowmelt-dominated period (late May to mid-July), subalpine (≤2300 m) and alpine (>2300 m) regions experienced increases in open water, non-woody, and woody/shrub vegetation while barren land decreased. On the other hand, the rainfall-dominated period (late July to mid-September) revealed a decline in open water area and an increase in barren land, so suggesting possible seasonal water constraints and vegetation changes. For Objective 3, the estimated proportion (P%) of open water evaporation in relation to volumes of forest ecosystem evapotranspiration. Historically, P% was 2.4% during the snowmelt-dominated period and 2.1% during the rainfall-dominated period. Especially in earlier stages of the hydrologic year, these trends indicate rising contributions of surface water bodies to total evapotranspiration. The consequences comprise changed water availability, habitat changes, and the long-term viability of wetland ecosystem services. The noted seasonality of hydrological changes and acceleration highlights the need for adaptive water management and conservation strategies considering local and regional dynamics.The author received funding provided by the Natural Sciences and Engineering Research Council of Canada (NSERC; grant no. 2017-04362), Alberta Innovates, the Nexen Fellowship in Water Resources, the Columbia Wetlands Stewardship Partners and the Shuswap Band’s Columbia Headwaters Aquatic Restoration Secwépemc Strategy (CHARS) project
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
Spatio-temporal variations in snow depth and associated driving mechanisms in a temperate mesoscale mountainous watershed
Full text linkSeasonal snow is a significant source of runoff in Western Canada. Mountainous snow depth distributions are challenging to quantify over large areas. Enhanced monitoring methods can provide the necessary data for more accurate flood and drought forecasts. Using multiple datasets, this research provides the foundation to optimize LiDAR snow depth data collection. Snow depth distribution consistency during mid-winter and melt onset was assessed and depth driver (elevation, aspect, slope, TPI and canopy cover) importance was determined. Consistent inter-annual relationships between aspect, TPI, elevation, treeline and snow depth distributions could be exploited in future sampling designs. Random forest models were utilized to predict depth over a 103 km2 area, based on high resolution (3m) watershed scale and partial datasets. Statistically significant correlations were found between parent and modelled datasets in all trials. This thesis illustrates that machine learning is a promising means of optimizing airborne LiDAR snow surveys in headwater environments
Innovations in headwater snow monitoring in the southern Canadian Rockies
No full textThe Alberta Rocky Mountain region is a large contributor to the water supply for populations, ecosystems, wildlife, and industry. Water resource managers and governmental policy makers require estimates to ensure there is a sufficient supply to meet increasing demands while at the same time responding to potential decreases in the supply from a changing climate. This research was conducted in the Southwestern Alberta Rocky Mountains and explored precipitation patterns and quantified spatially explicit estimates of winter snowpack SWE water yields to address the need for improved headwater resource assessments. There is high spatial and temporal variability of precipitation and the winter snowpack in mountain regions. Precipitation gauges are prone to sensor- and wind-induced measurement errors. Quality Control Corrections were applied to two valley and one alpine gauge. After corrections, the alpine site had up to a 50% increase in precipitation depths while the valley sites had up to a 5% change. A seasonality component was present where the alpine site had up to 80% more precipitation in the winter months and all sites received 50% to 70% lower precipitation in the summer months. This seasonality caused valley to alpine sites to have different monthly elevational precipitation gradients. Six “single point in time” mesoscale snow water equivalent (SWE) estimates were created using a combination of a) airborne lidar derived or predicted snow depths; and b) publicly accessible snowpack monitoring datasets to constrain snow density models for each SWE estimate. The most productive elevation zone was at the mid-mountain treeline between 1900 masl to 2200 masl producing approximately half of the estimated total water yield. Precipitation corrections, elevational precipitation gradients, and SWE water yields created in this research can be used by water managers to calibrate models used to derive real-time Alberta water resource estimates.Natural Sciences and Engineering Council Discovery Grants program [grant number 2017-04362], Alberta Innovates Energy and Environmental Solutions – Water Innovation Program [grant number E323726, Government of Alberta Environment and Protected Areas. [grant number 19GRAEM26], Alberta Research Capacity Program and Canada Foundation for Innovation (grant: 32436), Canada Foundation for Innovation and Western Economic Diversification Canada
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