1,720,955 research outputs found
Evaluating the effects of wild- and prescribed fire on the taxonomic and functional diversity of soil-dwelling arthropods in the New Jersey Pinelands, a high-disturbance system
No full textPrescribed fire and wildfire are among the largest disturbances to impact forest soils each year, and the impact of such events on the structure and function of soil arthropod communities remains poorly understood. Despite this lack of knowledge, soil arthropod communities are recognized as significant contributors to soil productivity and nutrient cycling at the broader ecosystem level. Differences in the functional groups that compose these communities can lead to contrasting responses to environmental change and stress. For soil- and litter-dwelling arthropods, fire events have been shown to cause local extinctions and subsequent rapid colonization by regional community members with high dispersal ability, yet little is known about how fire severity influences this effect. We present the preliminary results of an ongoing study, exploring the relationship between fire severity and the taxonomic and functional diversity of soil- and litter-dwelling arthropods, as a step toward better understanding fire as a driver of change in soil communities. Our work focuses on the New Jersey Pinelands, a high-disturbance landscape with frequent prescribed fire and wildfire. Arthropods were sampled from pitfall traps in July and August 2020 from forest plots, which were either burned or fire-excluded for at least 20 years. Using tree char height as a proxy for the Composite Burn Index, burned plots were categorized by fire severity as low, moderate, or high. Our models indicate that arthropod richness generally decreases with increasing fire severity, but arthropod abundance is maximized in sites exposed to low severity fire at annual frequency. At intermediate levels of disturbance, community-level biomass is maximized, while the community-weighted mean of trophic level is minimized. These results indicate that arthropods in the New Jersey Pinelands experience more even distribution of trophic roles, decreased predation, and improved access to food resources
Characterizing the nitrogen uptake of American cranberry
No full textInorganic nitrogen is an important resource for many plants, and mycorrhizal associations have been known to increase or otherwise assist in nutrient uptake for their hosts. Previous research has established that American cranberry, Vaccinium macrocarpon, is more efficient in nitrogen uptake when associated with ericoid mycorrhiza (Kosola, et. al. 2007). Given this information, this project aims to determine if ericoid mycorrhiza preferentially absorbs nitrogen obtained from organic material, instead of inorganic fertilizers. Specifically, this project will evaluate the source of nitrogen in V. macrocarpon when associated with ericoid mycorrhizal fungi.
Macrocarpon will be grown over a period of several weeks in an environmental chamber, with and without ericoid mycorrhizal fungi. Mycorrhizal associations will be promoted in half the plants by adding soil from a working cranberry bog to their pots. All plants will be treated with an inorganic ammonium nitrate tracer; half the plants will also be exposed to organic nitrogen via a treatment of leaf litter mixed in with their soil. Mass spectroscopy will quantify the source of nitrogen in each plant.
Based on previous studies, it is primarily anticipated that ericoid mycorrhiza will preferentially absorb and deliver to V. macrocarpon nitrogen acquired from organic sources. Plants with ericoid mycorrhizal associations will have higher nitrogen content than those without. Plants with ericoid mycorrhizal associations and additional organic nitrogen (as leaf litter) will have the highest nitrogen content. Overall, it is anticipated that mycorrhizal associations will promote overall health of the V. macrocarpon plant.This short film was presented at the first annual Celebration of Undergraduate Research and Creative Activity while the author was an undergraduate student at Rutgers University-Camden
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
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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