1,721,003 research outputs found
“Till death do us apart”: The common destiny of brown hare and its parasite community
Full text linkAlthough parasites may threaten individual hosts' survival and reproduction, their role as an essential part of ecosystem functioning and biodiversity has been recognized. In Northern Italy, the hare population has evidently declined since 2008.This paper aims to assess the relationship between host demographic trends and helminth parasite community diversity in a two-year survey in Northern Italy to evaluate the impact of parasites on hosts and confirm the hypothesis that endangered host populations are poor in parasites.In 2013 and 2015 the viscera of 54 and 61 hares legally hunted in agro-ecosystems of the Po Plain were collected. This area is characterized by heavy anthropic pressure: more than 60% of the landscape is represented by agricultural or urbanized territories.No intestinal cestodes were detected. Trichuris sp. and Micipsella numidica were collected in 2015 only; Trichostrongylus retortaeformis, Taenia pisiformis cysticercosis and bronchopulmonary lesions caused by small strongyles were observed in both years. The richness and evenness appeared increased in the second year of the survey, although lower than those obtained by literature data from similar populations examined in the last two decades of 1900.The dominant helminth, T. retortaeformis, was more abundant in individuals with higher weight, while pathological findings were mostly unrelated to this nematode infection; this is consistent with a reduced action, even no harm, of the parasites on the individual host or population level.Our results suggest that the conservation of hosts, environment, and parasites cannot be achieved separately and that parasites and wildlife hosts' destinies are intimately linked, confirming the complexity of ecosystems and the need to contemplate parasite biodiversity in conservation strategies
Transitional cell carcinoma of the renal pelvis in two dogs
No full textTransitional cell carcinoma (TCC) of the renal pelvis was found in two dogs, a 7-year-old male English Setter and a 11-year-old female Shetland shepherd. Affected dogs were presented for clinical examination without any specific symptoms but haematuria in case 1 and occurrence of whitish material in the urine of case 2; neoplastic disorders were discovered with ultrasonographic investigation and fine needle aspiration biopsy. Histopathological examination was carried out after nephrectomy and ureterectomy of the affected kidney of both dogs, and confirmed the diagnosis of non-invasive and low grade TCC in case 1 and of infiltrating TCC in case 2. The clinical, gross, cytological and histopathological features of these rare tumours originating from transitional epithelium of the renal pelvis are reported. © 2003 Blackwell Verlag
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
Genital tract involvements in a bull affected by bovine besnoitiosis
Full text linkObjective
To describe the gross and histopathological testicular lesions observed in a 14-months.old
Limousine bull, imported from France and referred for thickening of the skin and enlargement
of the testis and finally diagnosed as affected by Besnoitiosis. The diagnosis was confirmed by
histological investigation of skin sampled via biopsy.
Materials and Methods
Gross examination and histological investigation were carried out on the reproductive tract of the bull
sampled during slaughtering. The considered parts were skin of the scrotum, testis, testicular coverings,
epididymis, penis, and penis retractor muscle.
These tissue were fixed in 10% buffered formalin, embedded in paraffin wax, and processed for histological
investigation.
Results
Gross examination showed: thickening and lichenification of the scrotal skin (a), visible cysts at the level of
the testicular coverings (b), preputial mucosa (c), hyperemia of the right testis (d).
The main microscopical finding was the presence of several Besnoitia. spp cysts in the skin and subcutaneous
tissue of the scrotum, in the testicular coverings as well as in the testicular tubules (e), and epididymis. (f)
The Besnoitia spp. cysts ranged in size from 250 to 300 μm in diameter. They had a 10-20 μm thick wall with
three layers: an outer hyaline layer, a middle layer with host cells cytoplasm and nuclei, and an inner
membrane with the parasitophorous vacuole containing typical 7.0×2.0 μm basophilic banana-shaped
Besnoitia spp. Bradyzoites.
Plasmocytic and histiocytic inflammatory reaction, with sparse eosinophilic granulocytes infiltration were
observed around some broken cysts.
Numerous Besnoitia spp. cysts were also observed in the cross section of the penis (g) and the penis retractor
muscle (h). A moderate inflammatory response, composed by macrophages, eosinophils and scattered
lymphocytes, was seen near and around the cysts.
Discussion and conclusions
The presence of cysts and its secondary inflammatory reactions may explain the impaired fertility that has
been already described in the case of Besnoitiosis. Potential explanations may be:
• interference with normal spermatogenesis by the cysts in the interstitial spaces and under the epithelial
cells in the seminiferous tubules;
• direct pressure on the germinal epithelial cells by the cysts that can cause pressure atrophy of epididymal
and/or testicular tissues;
• reduction of the blood flow, local testicular necrosis and development of fibrotic foci due to the
inflammation caused by the cysts in the blood vessel walls of the testis and pampiniform plexus, with
repercussion on the seminiferous tubule health;
• abnormal thermoregulation of the testis due to the thickened scrotum;
• abnormal thermoregulation of the testis due to vascular lesions in pampiniform plexus provokiong
testicular degeneration;
• tissutal fibrosis due to the inflammatory reaction to the presence of the cysts
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
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