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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
C. jejuni mammary infection in cattle : case report
No full textINTRODUCTION - The contamination of bulk milk from pathogenic microorganisms such as C. jejuni is assuming more importance as a consequence of the increasing consumption of raw milk.We describe two cases of dairy farms located in the Po Valley, characterised by repeated detection of C. jejuni in bulk milk. In both cases the source of contamination of bulk milk (and consequently of raw milk) was due to a cased of mammary infection in a cow. CASES - In both cases just one infected quarter of a single cow was able to contaminate the bulk milk of respectively 270 and 180 lactating cows. The persistent infection of the quarter was documented for at least 90 days in one herd and for 30-40 days in the other herd. Antibiotic treatment of the infected cow in the first farm was effective in the cure of mammary infection. DISCUSSION AND CONCLUSIONS - Although C. jejuni was also detected in the faeces of some animals, the segregation of the subject with mammary infection was effective in eliminating the primary source of contamination, with the result of an undetectable level of the microrganism in bulk milk. The analysis of pooled milk samples by culture and PCR, followed by individual testing, prooved to be efficient tools for the identification of infected subjects. These data demonstrate the importance to consider the possibility of udder infection of even a single cow, as a source of bulk milk contamination, when C. jejuni is repeatedly detected
Effects of propolis flavonoids on virus infectivity and replication.
No full textThe effect of five propolis flavonoids on the infectivity and replication of some herpesvirus, adenovirus, coronavirus and rotavirus strains has been studied. Experiments were performed in vitro in cell cultures using the viral plaque reduction technique. The cytotoxicity of flavonoids, including chrysine, kaempferol, acacetin, galangin and quercetin, was evaluated on uninfected monolayers to determine their effect on cell growth and viability. Chrysine and kaempferol caused a concentration-dependent reduction of intracellular replication of herpes-virus strains when monolayers were infected and subsequently cultured in a drug-containing medium. However, virus infectivity was not significantly affected. Acacetin and galangin had no effect on either the infectivity or replication of any of the viruses studied. Quercetin reduced infectivity and intracellular replication, but only at the highest concentrations tested
Adenoviral fibrinous enteritis in calves
No full textTwo calves coming from different herds showed at post-mortem examination a fibrinous enteritis with mucosal necrosis particularly in the ileal-colonic tract. Histologically, amphophilic intranuclear inclusion bodies were the main feature. They were located in the endothelial cells of the intestine and mesenteric lymph cells. Ultramicroscopic examination of the inclusion bodies revealed the presence of an adenovirus. In one case the virus was isolated on cell cultures and further classified as bovine adenovirus type 4
Comparison between specific immunoperoxidase staining and bacteriological culture in the diagnosis of renal leptospirosis of pigs
No full textSeventy-two pigs were examined for the presence of leptospires in the kidney by both bacteriological culture and an immunoperoxidase procedure performed on formalin-fixed, paraffin-embedded sections of tissue with a primary antibody raised in rabbits against serovar pomona. The methods were in accordance in 62 of 70 (89 per cent) of the specimens. Compared with culture the sensitivity of the immunoperoxidase procedure was 30 of 38 (78 per cent) and its specificity 100 per cent; the predictive value of a positive result was 100 per cent, of a negative result, 80 per cent. The major advantages of the immunoperoxidase procedure are specificity, speed of execution and the possibility of simultaneous visualisation of leptospiral antigen and microscopic lesion
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