1,720,962 research outputs found
Loss of protozoan and metazoan intestinal symbiont biodiversity in wild primates living in unprotected forests
Full text linkIn light of the current biodiversity crisis, investigating the human impact on non-human primate
gut biology is important to understanding the ecological signifcance of gut community dynamics
across changing habitats and its role in conservation. Using traditional coproscopic parasitological
techniques, we compared the gastrointestinal protozoan and metazoan symbiont richness of
two primates: the Udzungwa red colobus (Procolobus gordonorum) and the yellow baboon (Papio
cynocephalus). These species live sympatrically in both protected and unprotected forests within
the Udzungwa Mountains of Tanzania with distinct ecological adaptations and diets. Our results
showed that terrestrial and omnivorous yellow baboons had 2 (95% CI 1.47–2.73) and 3.78 (2.62–5.46)
times higher gut symbiont richness (both including and excluding rare protozoans) compared to the
arboreal and leaf-eating Udzungwa red colobus in unprotected and protected forest, respectively.
We also found a consistent depletion of symbiont richness in red colobus living in the unprotected
forest fragment compared to the continuous protected forests [the latter having 1.97 times (95% CI
1.33–2.92) higher richness], but not in yellow baboons. Richness reduction was particularly evident in
the Udzungwa red colobus monkeys, confirming the pattern we reported previously for gut bacterial
communities. This study demonstrates the impact of human activities even on the microbiodiversity
of the intestinal tract of this species. Against the background of rapid global change and habitat
degradation, and given the health benefts of intact gut communities, the decrease in natural gut
symbionts reported here is worrying. Further study of these communities should form an essential
part of the conservation framework
First report of Cercopithifilaria spp. in dogs from Eastern Europe with an overview of their geographic distribution in Europe.
No full textDogs in Europe may be parasitized by a variety of species of filarioids. While some species have been studied for decades, others have been only recently reported, and their range of distribution is still unknown. The present study was aimed to investigate the occurrence of Cercopithifilaria spp., whose microfilariae reside in the dermis and are transmitted by Rhipicephalus sanguineus s.l. ticks, in a dog population from Romania and to present the current knowledge of their distribution in Europe. Sampling was performed in a rural locality from Danube Delta region of Romania, location chosen due to the presence of the only known vector for these species. Skin samples were collected from 39 dogs. The samples were tested for the presence of Cercopithifilaria spp. by PCR methods. One animal (2.56 %) was positive, and the amplified sequence showed a 100 % similarity to Cercopithifilaria bainae. This study reports C. bainae for the first time in Eastern Europe, extending the known range of the genus in Europe
Cryptosporidium from tortoises: Genetic characterisation, phylogeny and zoonotic implications
No full textCryptosporidiosis is a disease caused by apicomplexan parasites of the genus Cryptosporidium, which affect the gastrointestinal tract of humans and animals worldwide. In the present study, Cryptosporidium isolates from captive European tortoises (Testudo graeca, Testudo hermanni and Testudo marginata) in Italy were genetically characterised using gene/s encoding Cryptosporidium oocyst wall protein (COWP) and/or the hypervariable segment internal to the SSU rDNA. Six isolates from T. graeca, T. hermanni and T. marginata revealed 100% sequence identity with the zoonotic Cryptosporidium pestis (Cryptosporidium parvum 'bovine genotype'), while a sequence from one T. marginata was a unique uncharacterised genotype (Cryptosporidium sp. ex T. marginata). The new genotype is phylogenetically characterised as belonging to the intestinal cryptosporidial lineage. The present study indicates that tortoises may disseminate Cryptosporidium oocysts in the captive environment. The identification of the zoonotic genotype in the faeces of captive European tortoises indicates a potential risk for humans within the household
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
First data on Cytauxzoon and Hepatozoon in wildcats (Felis silvestris silvestris) in North-eastern Italy
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