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A floristic analysis of the marine algae and seagrasses between Cape Mendocino, California and Cape Blanco, Oregon
Get PDFThe biogeographic area between Cape Mendocino, California and Cape Blanco, Oregon spans over 320 km and is characterized by prominent coastal headlands that act as genetic and species barriers for marine organisms. Because of a lack of a current macroalgal species list for this area, this study aimed to (i) compare patterns of intertidal macroalgal species composition for the poorly described coastline at four sites, and to (ii) compile a macroalgal and seagrass flora based on current findings and historical records. Collections were made in the spring and summers of 2010 and basic ecological habitat attributes for each species were recorded. Similarities in the macroalgal composition across the four sites were investigated using hierarchical clustering based on a presence/absence matrix for each species. A total of 162 species of marine macroalgae (103 Rhodophyta, 33 Heterokontophyta, Phaeophyceae, and 26 Chlorophyta) and 2 species of seagrasses (Anthophyta) were identified. The sites formed a latitudinal gradient of similarity; the two northern sites clustered together as did the two southern sites. Across all four sites, more than half of the taxa were found in the low intertidal. The within site comparison of taxa based on zonation revealed that Crescent City differered from the other three sites. One near-endemic species, Cumathamnion sympodophyllum M.J. Wynne K. Daniels, and one invasive species, Sargassum muticum (Yendo) Fensholt were found. Combined with historical accounts, the macroalgal flora between the Capes consists of 322 macroalgal taxa (201 Rhodophyta, 70 Heterokontophyta, Phaeophyceae, and 51 Chlorophyta) and 4 species of seagrasses. The results indicate a relatively high area of biodiversity of 134 species per degree latitude. The Cheney ratio designation is a cold-temperate flora with closer affinities to Oregon and Washington than to southern California. In comparison to historical records by Dawson and Doty, seven new records were found. Furthermore, Dawson and Doty's floras list 87 species that were not found, the discrepancy laying either in sampling efficiency or recent range shifts. This study was a first attempt to characterize the marine flora between Cape Mendocino and Cape Blanco and suggests that the capes act as a biogeographic barrier and important transition zone for some species of macroalgae in the Northeast Pacific.Thesis (M.A.)--Humboldt State University, Biology, 201
Ecophysiology and Taxonomy of Saccharina latissima forma angustissima (Laminariales, Phaeophyceae) From the Gulf of Maine, USA
No full textThe overarching theme of this doctoral dissertation was to resolve the taxonomic status of an endemic narrow-bladed kelp, Saccharina latissima forma angustissima (Laminariales, Phaeophyceae), which has a very restricted distribution of 8 nautical miles in the Gulf of Maine, USA. Since the kelp only grows on ledges and islands exposed to high ocean swells, it was unknown if phenotypic plasticity alone was driving its morphology or if the kelp was a distinct genotype (a population with heritable traits). I incorporated lab and fieldwork to discriminate genetic divergence of this kelp, investigated temperature and light requirements of the gametophytic and juvenile sporophytic stages, and its potential use for sustainable aquaculture. The final objective was to tease apart existing relationships of parapatric speciation, where gene flow is limited by the extreme habitat.
In Chapter 1, I used a multi-locus genetic approach to answer questions about the phylogenetic placement of S. latissima f angustissima. The results revealed the need for a new combination and status elevation to Saccharina angustissima comb. nov. & stat. nov. (Collins) Augyte, Yarish & Neefus. In Chapter 2, I examined the ecophysiological temperature and light tolerance of its early developmental stages, specifically looking at the response of gametophytes and juvenile sporophytes. For Chapter 3, I worked with two aquaculture companies in the Gulf of Maine to domesticate and commercially cultivate S. angustissima at two farm sites and provide data on morphometric traits, biomass yields, blade tissue analysis and ecosystem services. In the last Chapter 4, using microsatellite data, I investigated the population genetic structure of S. latissima and S. angustissima in across four sites in the Northwest Atlantic and found some genetic differentiation between the two species as well as between other S. latissima populations in Long Island Sound and the Gulf of Maine.
In conclusion, directional selection has propelled this unique kelp to persist and colonize an extreme ecological niche and speciate. This reproductive isolation has led to incipient speciation of a Saccharina sp. in the Northwest Atlantic. Finally, as a result of my efforts there has been the domestication of a new kelp crop in New England
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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