1,720,998 research outputs found
Seroprevalence survey of Chlamydophila abortus infection in breeding goats on commercial farms in northern Namibia
Get PDFDissertation (MSc (Veterinary Science))--University of Pretoria, 2007.A total of 1076 sera from breeding goats were randomly collected from 24 different farms and tested with CHEKIT®-ELISA (Dr. Bommeli AG-IDEXX, Switzerland) for antibodies against Chlamydophila abortus. The farms were divided into two categories of 12 farms each, depending on their level of observed abortions over the previous 12 months: those with insignificant (<5 %) levels of abortions and those with significant (≥5 %) levels of abortions. The farmers were also interviewed on their level of awareness about chlamydophilosis and whether or not they were doing regular preventive vaccination against the disease. The study determined the seroprevalence levels of 25% at farm level and 8 % at individual animal level (at 95% confidence level). A total of 6 out of 24 farms had at least one positive breeding animal. Only 5 out of the 24 (20.8%) farmers interviewed were aware of chlamydophilosis and its zoonotic dangers. None of the 24 farmers interviewed practised any vaccination against chlamydophilosis. There was a significantly higher number of seropositive animals from farms with significant levels of abortions compared to those animals from farms with insignificant levels of abortions (P=0.0000). The study underscored the need for more farmer awareness and training on chlamydophilosis and its zoonotic dangers.Veterinary Tropical DiseasesMScunrestricte
Knowledge, attitudes and practices analysis, prevalence and molecular detection of Neospora caninum and Toxoplasma gondii in livestock in the Khomas region of Namibia
Get PDFThesis (PhD (Veterinary Science))--University of Pretoria, 2023.This study chiefly focussed on the Khomas region of Namibia, and the research areas were: (1)
the knowledge, attitudes and practices regarding neosporosis and toxoplasmosis among livestock
farmers in the Khomas region and animal health practitioners in the whole country; (2) the
seroprevalence and associated risk factors of Neospora caninum in cattle; (3) the seroprevalence
and associated risk factors of Toxoplasma gondii in sheep and goats; (4) molecular investigation
of N. caninum DNA in cattle and, (5) the molecular detection of T. gondii in sheep and goats in
abattoir samples.
Only 15.9% (10/63) of the livestock farmers had heard about neosporosis or toxoplasmosis or
knew how animals get infected (p<0.0001). Five per cent (3/63) of the farmers knew the risks
associated with keeping dogs and cats concerning neosporosis and toxoplasmosis, respectively
(p<0.0001). None of the animal health practitioners (n=51) routinely requested N. caninum or T.
gondii laboratory tests in cases of cattle, sheep or goat abortions. Although all animal health
practitioners indicated they routinely interacted with livestock farmers, none regularly discussed
neosporosis or toxoplasmosis.
Five point seven per cent (42/736) of the bovine sera were seropositive to N. caninum. Eight of
the 32 establishments had at least one positive animal, giving a herd-level seroprevalence of 25%.
There was no significant association between N. caninum seropositivity in cattle and the presence
of dogs, jackals, history of abortions, farm size, and the number of cattle or average annual rainfall.
The establishments with moderate to high numbers of Feliformia were 9.8 times more likely to be
seropositive to N. caninum than those with none to low levels of the former (p=0.0245).
Overall, 3.68% (11/299) of the sheep sera were seropositive to T. gondii, and 61.54% (8/13) of the
sheep flocks tested had at least one positive animal. Only 0.29% (1/345) of the goat sera were seropositive to T. gondii, and one of the 19 goat flocks had at least one positive animal, giving a
herd-level prevalence of 5.26%. Sheep flocks had significantly greater animal-level and flocklevel prevalences than goats (p<0.05) and were 13.14 times more likely to be seropositive (OR =
13.14; CI 95%: 1.686-102.382) than goat flocks. Seropositivity to T. gondii was positively
associated with the total number of sheep at the farming establishment, history of abortions and
farm size (p<0.05), but not goats. The study concluded that sheep were probably more exposed to
T. gondii infection than goats and that the T. gondii seroprevalence level in the Khomas region
was very low compared to other countries.
One hundred and ninety-nine bovine abattoir samples were collected from different animals,
comprising 110 brain samples and 75 heart muscle samples. In addition, there were 14 whole
blood samples from N. caninum seropositive cattle. The collected samples were tested using a
conventional PCR targeting the pNc5 gene. All the samples tested were negative. The authors
concluded that the negative results could be due to the low prevalence of N. caninum infection
caused by adverse weather conditions and that a future study targeting aborted fetuses over a more
extended period could yield positive results.
The T. gondii molecular study analysed 174 brain and heart tissue samples from sheep and goats
for the presence of T. gondii DNA using nested PCR targeting the B1 gene. The tissue samples
were obtained from animals at abattoirs designated for human consumption. The study found that
16.7% of the samples tested positive for T. gondii DNA, with a higher prevalence in sheep (17.4%)
than in goats (7.7%). Eight of the 29 positive samples were successfully sequenced using the
Sanger method. All isolates identified were closely related to T. gondii type III genotype,
exhibiting alignment scores ranging from 96.44% to 100%. This study emphasizes the public
health hazards of consuming undercooked sheep and goat meat and highlights the pressing need
to introduce control measures to mitigate human exposure.Veterinary Tropical DiseasesPhD (Veterinary Science)UnrestrictedFaculty of Veterinary Scienc
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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