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Trummer, Loreen1996.zip
No full textHemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahi) G.N. Jones subsp. tsugense (western hemlock race)) is the most important and widespread disease of old-growth western hemlock forests in the Pacific Northwest. Although heavy infection of dwarf mistletoe can significantly increase growth loss and mortality of host trees, the parasite is also considered an important ecological component of forests influencing stand structure, species composition, and wildlife habitat. This retrospective study was conducted in stands that sustained extensive windthrow in the past and was designed as a simulation for stand structure and disease conditions expected after use of silvicultural systems that retain overstory canopy trees in a managed forest. The specific objectives were to: 1. characterize the forest structure and dwarf mistletoe component of stands that developed after catastrophic wind storms in the late 1800's; and 2. develop and validate a model, using site, plot, and tree variables, that predicts the dwarf mistletoe rating of hemlock trees that have been exposed to the pathogen for approximately a century. Results indicated that retention of overstory infected hemlock trees in southeast Alaska forests will result in pathogen spread to and intensification on hemlock trees that have developed since the late 1800's (post-disturbance trees), but not to the devastating levels predicted by previous research in the coastal forests of British Columbia, Washington, or Oregon. On Kuiu Island, the retention of an average of 3 heavily infected overstory residual trees/plot (83 residual trees/ha) resulted in nearly 100 percent infection of post-disturbance hemlock trees within a plot. Of those trees infected, less than one-fifth had heavy infection (a dwarf mistletoe rating of 5 or 6), and approximately one-half had moderate infection (a dwarf mistletoe rating of 3 or 4). On Chichagof Island, the retention of an average of 2 heavily infected residual trees/plot (69 residual trees/ha) resulted in nearly 100 percent infection of post-disturbance hemlock trees within a plot. Of those trees infected, less than ten percent had heavy infection and approximately one-third had moderate infection. A mathematical model that predicted dwarf mistletoe rating on post-disturbance hemlock trees was developed from eight stands on Kuiu Island and the generality of the variables was tested in two stands on Chichagof Island. The Kuiu Island model predicted that the mean dwarf mistletoe rating of post-disturbance hemlock trees within a plot increased with increasing numbers and dwarf mistletoe ratings of residual and advanced regeneration trees within a plot. No other factors that described site or tree conditions within a plot appeared important in the model. Sitka spruce trees, though rare hosts of dwarf mistletoe, did not appear to increase the mean dwarf mistletoe rating of postdisturbance hemlock trees within a plot. When present in sufficient numbers, spruce trees may act as barriers to pathogen spread, although further analysis is needed to confirm a barrier effect. The Chichagof Island models, developed separately for the two stands, also predicted that the mean dwarf mistletoe rating of post-disturbance hemlock trees within a plot increased with increasing numbers and dwarf mistletoe rating of residual trees within a plot. The importance of advanced regeneration trees could not be verified in either stand on Chichagof Island since most plots lacked this tree type
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Modeling hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) spread and intensification in mature uneven-aged forests in southeast Alaska
Get PDFHemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahi) G.N. Jones subsp. tsugense (western hemlock race)) is the most important and widespread disease of old-growth western hemlock forests in the Pacific Northwest. Although heavy infection of dwarf mistletoe can significantly increase growth loss and mortality of host trees, the parasite is also considered an important ecological component of forests influencing stand structure, species composition, and wildlife habitat. This retrospective study was conducted in stands that sustained extensive windthrow in the past and was designed as a simulation for stand structure and disease conditions expected after use of silvicultural systems that retain overstory canopy trees in a managed forest. The specific objectives were to: 1. characterize the forest structure and dwarf mistletoe component of stands that developed after catastrophic wind storms in the late 1800's; and 2. develop and validate a model, using site, plot, and tree variables, that predicts the dwarf mistletoe rating of hemlock trees that have been exposed to the pathogen for approximately a century. Results indicated that retention of overstory infected hemlock trees in southeast Alaska forests will result in pathogen spread to and intensification on hemlock trees that have developed since the late 1800's (post-disturbance trees), but not to the devastating levels predicted by previous research in the coastal forests of British Columbia, Washington, or Oregon. On Kuiu Island, the retention of an average of 3 heavily infected overstory residual trees/plot (83 residual trees/ha) resulted in nearly 100 percent infection of post-disturbance hemlock trees within a plot. Of those trees infected, less than one-fifth had heavy infection (a dwarf mistletoe rating of 5 or 6), and approximately one-half had moderate infection (a dwarf mistletoe rating of 3 or 4). On Chichagof Island, the retention of an average of 2 heavily infected residual trees/plot (69 residual trees/ha) resulted in nearly 100 percent infection of post-disturbance hemlock trees within a plot. Of those trees infected, less than ten percent had heavy infection and approximately one-third had moderate infection. A mathematical model that predicted dwarf mistletoe rating on post-disturbance hemlock trees was developed from eight stands on Kuiu Island and the generality of the variables was tested in two stands on Chichagof Island. The Kuiu Island model predicted that the mean dwarf mistletoe rating of post-disturbance hemlock trees within a plot increased with increasing numbers and dwarf mistletoe ratings of residual and advanced regeneration trees within a plot. No other factors that described site or tree conditions within a plot appeared important in the model. Sitka spruce trees, though rare hosts of dwarf mistletoe, did not appear to increase the mean dwarf mistletoe rating of postdisturbance hemlock trees within a plot. When present in sufficient numbers, spruce trees may act as barriers to pathogen spread, although further analysis is needed to confirm a barrier effect. The Chichagof Island models, developed separately for the two stands, also predicted that the mean dwarf mistletoe rating of post-disturbance hemlock trees within a plot increased with increasing numbers and dwarf mistletoe rating of residual trees within a plot. The importance of advanced regeneration trees could not be verified in either stand on Chichagof Island since most plots lacked this tree type
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TrummerLoreen1996.pdf
No full textHemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahi) G.N. Jones subsp. tsugense (western hemlock race)) is the most important and widespread disease of old-growth western hemlock forests in the Pacific Northwest. Although heavy infection of dwarf mistletoe can significantly increase growth loss and mortality of host trees, the parasite is also considered an important ecological component of forests influencing stand structure, species composition, and wildlife habitat. This retrospective study was conducted in stands that sustained extensive windthrow in the past and was designed as a simulation for stand structure and disease conditions expected after use of silvicultural systems that retain overstory canopy trees in a managed forest. The specific objectives were to: 1. characterize the forest structure and dwarf mistletoe component of stands that developed after catastrophic wind storms in the late 1800's; and 2. develop and validate a model, using site, plot, and tree variables, that predicts the dwarf mistletoe rating of hemlock trees that have been exposed to the pathogen for approximately a century. Results indicated that retention of overstory infected hemlock trees in southeast Alaska forests will result in pathogen spread to and intensification on hemlock trees that have developed since the late 1800's (post-disturbance trees), but not to the devastating levels predicted by previous research in the coastal forests of British Columbia, Washington, or Oregon. On Kuiu Island, the retention of an average of 3 heavily infected overstory residual trees/plot (83 residual trees/ha) resulted in nearly 100 percent infection of post-disturbance hemlock trees within a plot. Of those trees infected, less than one-fifth had heavy infection (a dwarf mistletoe rating of 5 or 6), and approximately one-half had moderate infection (a dwarf mistletoe rating of 3 or 4). On Chichagof Island, the retention of an average of 2 heavily infected residual trees/plot (69 residual trees/ha) resulted in nearly 100 percent infection of post-disturbance hemlock trees within a plot. Of those trees infected, less than ten percent had heavy infection and approximately one-third had moderate infection. A mathematical model that predicted dwarf mistletoe rating on post-disturbance hemlock trees was developed from eight stands on Kuiu Island and the generality of the variables was tested in two stands on Chichagof Island. The Kuiu Island model predicted that the mean dwarf mistletoe rating of post-disturbance hemlock trees within a plot increased with increasing numbers and dwarf mistletoe ratings of residual and advanced regeneration trees within a plot. No other factors that described site or tree conditions within a plot appeared important in the model. Sitka spruce trees, though rare hosts of dwarf mistletoe, did not appear to increase the mean dwarf mistletoe rating of postdisturbance hemlock trees within a plot. When present in sufficient numbers, spruce trees may act as barriers to pathogen spread, although further analysis is needed to confirm a barrier effect. The Chichagof Island models, developed separately for the two stands, also predicted that the mean dwarf mistletoe rating of post-disturbance hemlock trees within a plot increased with increasing numbers and dwarf mistletoe rating of residual trees within a plot. The importance of advanced regeneration trees could not be verified in either stand on Chichagof Island since most plots lacked this tree type
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
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
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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