1,720,960 research outputs found
GASTRO-INTESTINAL HELMINTH COMMUNITY OF LEPUS EUROPAEUS IN BOLOGNA PROVINCE (EMILIA ROMAGNA REGION): BIODIVERSITY DROP IN DECLINING POPULATIONS?
No full textSince the Seventies, a continual reduction of the European brown hare population (Lepus europaeus) has been observed in most European Countries, including Italy. In the Bologna Province, Emilia Romagna Region, after a recovery phase a sudden acceleration of the hare population decline was noticeable from 2008: the hare captured in protected areas for restocking dropped from about 7,000 in 2007-‘08 to 1,891 in 2014-’15.
In 2013, from September 15th to October 5th, 53 hares haunted in agro-ecosystems of the Po Plain (Province of Bologna, ATC BO2) were collected for parasitological analysis. All the helminthes were collected from the stomach and the intestine using standard parasitological techniques, preserved in 70% ethyl alcohol and 5% glycerin and therefore microscopically identified following clarification with 20% lactophenol. The sex of each hare and the weight of 52 of them were recordered by hunters; age class was assigned to 51 hare out of 53 by observing Stroh’s tubercle.
The animals examined were 40% adults and 60% juveniles, 57% females and 43% males. Mean weight was 3.4 Kg (range: 2.1-4.5 Kg). Only one helminth species was collected, i.e. the nematode Trichostrongylus retortaeformis. Thirty-eight out of 53 hare hosted T. retortaeformis (prevalence 72%); the mean parasite abundance was 22 helminth/examined-hare. Parasite prevalence was significantly higher in adults (95%) than in juveniles (54.8%) (Fisher exact test, p<0.01). Parasite abundance was significantly higher in adults and in heavier animals (multiple negative binomial regression with sex, age and weight as independent variables, p<0.05); parasites were significantly aggregated, with overall estimated k=0.29. None of the other gastro-intestinal helminth species commonly reported in hare (both nematodes and cestodes) were observed.
T. retortaeformis is the most common helminth of European brown hare. Several authors reported high prevalence of this parasite in Europe (50-91.7%). A prevalence of 92% had been reported about 20 years ago in the Bologna Province, but the helminth community, although dominated by T. retortaeformis, was characterized by a certain grade of biodiversity with an overall richness of 4 helminth species (3 nematoda and 1 cestoda).
Some authors report that severely T. retortaeformis infected animals can undertake chronic enteritis, mortality or body weight loss. In our case, the abundance of the infection is relatively low and it positively correlates to both the animal weight and age, suggesting no evident effect on parasitized individuals. In addition, the aggregation of parasites suggests that only a minimal part of host population would, if ever, be influenced by this infection.
T. retortaeformis infection has been also proposed as a possible causal agent of the cyclic population dynamics of L. timidus possibly mediated by the reduction in the body condition and fertility of the infected hosts. Although parasites can cause cyclical fluctuations in host populations (mediated by sub-lethal effects), they did not appear involved in long-lasting decline in hare populations.
A positive relationship between host density and parasite abundance is consistent with both theoretical and some empirical studies. The situation observed in our study area, and in particular low parasite abundance, is consistent with the low host density, that probably makes parasite transmission more difficult; in addition, the intense hare population turn-over, due also to seasonal hunt, make it difficult for parasites to gain high abundance due to the lack of older and heavy hosts. The absence of other usually observed parasite species is probably due to their lowest ability to infect hosts if compared with the “well-adapted” T. retortaeformis, usually dominant in hare parasite biocoenosis.
In conclusion, the critical situation of host population parallels with the critical loss of biodiversity observed in parasite community. This could eventually induce a harmful loop, since biodiversity is considered a stabilizing factor in ecological webs and the lack of specific brown hare parasites in biocoenosis may be a predisposing factor for the occurrence of exogenous and potentially dangerous parasite taxa in the hare population. The present study suggests that nor T. retortaeformis or other gastro-intestinal helminths were involved in the recent hare population decline (although it is not possible to ascertain that they are, or were, not involved in natural cyclic population dinamic); however, parasite community has probably suffered, direcltly (environmental mechanisms acting on both host and parasites) or indirecltly (mechanisms acting on host density and therefore on parasite transmission), the same until now unknown cause of brown hare decline
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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