1,721,070 research outputs found
Restoration of the 1936 statewide forest survey of Minnesota: data description and comparisons with 2014 forest conditions
No full text1 electronic resource (PDF; v, 39 pages, includes charts and illustrations)Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative–Citizen Commission on Minnesota Resources and the University of Minnesota’s College of Food, Agricultural and Natural Resources Sciences
Department of Forest Resources and the Minnesota Agricultural Experiment Station under Project MIN 42-019.Flanary, Merril H.; Anderson, Brian D.; Ek, Alan R.. (2016). Restoration of the 1936 statewide forest survey of Minnesota: data description and comparisons with 2014 forest conditions. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/182330
Restoration of the 1936 Statewide Forest Survey of Minnesota
No full textOver 300 stand and stock tables and summary of volume tables for Minnesota were restored from the first FIA Lake States forest survey conducted between 1930 and 1938. The level of detail of the data varied, but included area of forest cover types and stand size classes, and number of trees and volumes per acre by individual species. The data was presented in an Access database with a series of tables and queries. Definitions and further explanations about the restored historic data can be found in Staff Paper Series No. 241, Department of Forest Resources, University of MinnesotaLong-term forest plot datasets have proven invaluable for understanding the changing conditions and ecology across Minnesota’s 17.3 million acres of forestland. Data from past and present USDA Forest Service (USFS) Forest Inventory and Analysis (FIA) program efforts are of high
quality and are informed by thousands of field plot observations for each survey. The aim of this study was to locate historic forest records for Minnesota, identify useful data, and develop methodologies for digitizing and restoring data to a usable format.Funding provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative–Citizen Commission on Minnesota Resources and the University of Minnesota’s College of Food, Agricultural and Natural Resources Sciences Department of Forest Resources and the Minnesota Agricultural Experiment Station under Project MIN 42-019. In addition, the USDA Forest Service Northern Research Station staff provided support.Flanary, Merril H; Anderson, Brian D; Wilson, David C; Ek, Alan R. (2016). Restoration of the 1936 Statewide Forest Survey of Minnesota. Retrieved from the University Digital Conservancy, http://doi.org/10.13020/D60P4T
On a bi-virus epidemic model with partial and waning immunity
Full text linkWe propose a deterministic compartmental model to study the impact of partial and waning immunity on the spread of two competitive epidemic diseases, hereafter termed viruses. Building on a standard bi-virus SIS model, we introduce additional compartments to account for individuals who recovered from each virus, and tunable parameters to capture the level of virus-specific and cross protection acquired after recovery from a specific virus, and the rate at which such immunity could wane. We formalise the model as a system of nonlinear ordinary differential equations, which is amenable to analytical treatment, and we focus our analysis on two specialisations of the model. First, in the absence of waning immunity, we establish a global convergence result showing that, above the epidemic threshold, only the “fittest” virus becomes endemic. Second, in the absence of cross-immunity, we demonstrate instead that long-lasting co-existence of the two viruses may emerge, depending on the model parameters
Modeling and analyzing competitive epidemic diseases with partial and waning virus-specific and cross-immunity
Full text linkIn this paper, we consider a novel mathematical modeling framework for the spread of two competitive diseases in a well-mixed population. The proposed framework, which we term a bivirus SIRIS model, encapsulates key real-world features of natural immunity, accounting for different levels of (partial and waning) virus-specific and cross protection acquired after recovery. Formally, the proposed framework consists of a system of coupled nonlinear ordinary differential equations that builds on a classical bivirus susceptible-infected-susceptible model by means of the addition of further states to account for (temporarily) protected individuals. Through the analysis of the proposed framework and of two specializations, we offer analytical insight into how natural immunity can shape a wide range of complex emergent behaviors, including eradication of both diseases, survival of the fittest one, or even steady-state co-existence of the two diseases
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
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
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