1,720,973 research outputs found
Characterization of aeromonads and development of vaccine candidate from aeromonas hydrophila isolated from tilapia fish farms in Tanzania
Get PDFA Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor
of Philosophy in Life Sciences of Nelson Mandela African Institution of Science and
TechnologyTanzania produces less than half of the country annual demand in fish. Therefore, there is an
urgent need to produce more fish, particularly through fish farming. However, aeromonads
infections cause major lose in aquaculture worldwide and especially in developing countries,
including Tanzania, lacking advanced capacity for fish disease control and prevention. Poor
fish farming management practices, lack of data on prevalence, emergence of resistances to
commonly used drugs, drug residues and limited capacity to control aeromonads bacterial
infections emerged as major health problems in fish farming in Tanzania. This study aimed to
characterise the aeromonads species circulating in fish farms and then develop a monovalent
vaccine candidate from selected prevalent aeromonads specie for supporting tilapia fish
farming improvement in Tanzania. A cross sectional study was conducted in Ruvuma,
Mbeya, Iringa and Kilimanjaro regions between February 2017 and October 2018. A
questionnaire was administered to 32 selected fish farmers to explore their knowledge on
pond, fish health and diseases management practices. The results showed that the selected
farmers had limited knowledge on pond, fish health and disease management practices. Onfarm
training
on the same to these farmers would improve their knowledge. A total of 816
whole fish samples were aseptically collected from these 32 fish farms to detect and identify
aeromonads using molecular methods in order to establish the prevalence and characterise
their virulence properties. The overall prevalence of 24.6% was recorded. Seventy five
percent of the isolates had virulence genes of varying combinations and the in-vivo study
showed high mortality (98.3%) to isolates with more virulence genes indicating their capacity
to establish disease in a favourable environment. The Aeromonas hydrophila strain TZR72018
was
selected and attenuated using a novel thermo-continuous sub-culturing method to
develop a vaccine candidate. The experimental study was carried out to assess its protective
efficacy. The results showed that the vaccine candidate had acceptable protective efficacy of
82.3% and 71.4% when given through intraperitoneal injection (IP) and immersion (IM);
respectively. To the best of my knowledge this study reports the development of thermoattenuated
and stabilized A. hydrophila vaccine candidate for the first time in Tanzania or
elsewhere
Characterization of Aeromonads and development of Vaccine candidate from Aeromonas Hydrophila Isolated from Tilapia fish farms in Tanzania
No full textThesesTanzania produces less than half of the country annual demand in fish. Therefore, there is an
urgent need to produce more fish, particularly through fish farming. However, aeromonads
infections cause major lose in aquaculture worldwide and especially in developing countries,
including Tanzania, lacking advanced capacity for fish disease control and prevention. Poor
fish farming management practices, lack of data on prevalence, emergence of resistances to
commonly used drugs, drug residues and limited capacity to control aeromonads bacterial
infections emerged as major health problems in fish farming in Tanzania. This study aimed to
characterise the aeromonads species circulating in fish farms and then develop a monovalent
vaccine candidate from selected prevalent aeromonads specie for supporting tilapia fish
farming improvement in Tanzania. A cross sectional study was conducted in Ruvuma,
Mbeya, Iringa and Kilimanjaro regions between February 2017 and October 2018. A
questionnaire was administered to 32 selected fish farmers to explore their knowledge on
pond, fish health and diseases management practices. The results showed that the selected
farmers had limited knowledge on pond, fish health and disease management practices. On-
farm training on the same to these farmers would improve their knowledge. A total of 816
whole fish samples were aseptically collected from these 32 fish farms to detect and identify
aeromonads using molecular methods in order to establish the prevalence and characterise
their virulence properties. The overall prevalence of 24.6% was recorded. Seventy five
percent of the isolates had virulence genes of varying combinations and the in-vivo study
showed high mortality (98.3%) to isolates with more virulence genes indicating their capacity
to establish disease in a favourable environment. The Aeromonas hydrophila strain TZR7-
2018 was selected and attenuated using a novel thermo-continuous sub-culturing method to
develop a vaccine candidate. The experimental study was carried out to assess its protective
efficacy. The results showed that the vaccine candidate had acceptable protective efficacy of
82.3% and 71.4% when given through intraperitoneal injection (IP) and immersion (IM);
respectively. To the best of my knowledge this study reports the development of thermo
attenuated and stabilized A. hydrophila vaccine candidate for the first time in Tanzania or
elsewhereAfrican Development Bank (AfDB
Characterization of Aeromonads and development of Vaccine candidate from Aeromonas Hydrophila Isolated from Tilapia fish farms in Tanzania
No full textThesesTanzania produces less than half of the country annual demand in fish. Therefore, there is an
urgent need to produce more fish, particularly through fish farming. However, aeromonads
infections cause major lose in aquaculture worldwide and especially in developing countries,
including Tanzania, lacking advanced capacity for fish disease control and prevention. Poor
fish farming management practices, lack of data on prevalence, emergence of resistances to
commonly used drugs, drug residues and limited capacity to control aeromonads bacterial
infections emerged as major health problems in fish farming in Tanzania. This study aimed to
characterise the aeromonads species circulating in fish farms and then develop a monovalent
vaccine candidate from selected prevalent aeromonads specie for supporting tilapia fish
farming improvement in Tanzania. A cross sectional study was conducted in Ruvuma,
Mbeya, Iringa and Kilimanjaro regions between February 2017 and October 2018. A
questionnaire was administered to 32 selected fish farmers to explore their knowledge on
pond, fish health and diseases management practices. The results showed that the selected
farmers had limited knowledge on pond, fish health and disease management practices. On-
farm training on the same to these farmers would improve their knowledge. A total of 816
whole fish samples were aseptically collected from these 32 fish farms to detect and identify
aeromonads using molecular methods in order to establish the prevalence and characterise
their virulence properties. The overall prevalence of 24.6% was recorded. Seventy five
percent of the isolates had virulence genes of varying combinations and the in-vivo study
showed high mortality (98.3%) to isolates with more virulence genes indicating their capacity
to establish disease in a favourable environment. The Aeromonas hydrophila strain TZR7-
2018 was selected and attenuated using a novel thermo-continuous sub-culturing method to
develop a vaccine candidate. The experimental study was carried out to assess its protective
efficacy. The results showed that the vaccine candidate had acceptable protective efficacy of
82.3% and 71.4% when given through intraperitoneal injection (IP) and immersion (IM);
respectively. To the best of my knowledge this study reports the development of thermo
attenuated and stabilized A. hydrophila vaccine candidate for the first time in Tanzania or
elsewhereAfrican Development Bank (AfDB
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
Assessing the awareness, knowledge, attitude and practice of the community towards solid waste disposal and identifying the threats and extent of bacteria in the solid waste disposal sites in Morogoro municipality in Tanzania
No full textJournal articleSolid wastes comprise all the wastes arising from human and animal activities that are normally solid, discarded
as useless or unwanted materials. Health hazards associated with improper disposal of solid wastes to the
community were investigated in Morogoro municipality. The aim of the project was to investigate the solid
waste disposal practices and their health hazard implications to the community in Morogoro municipality. The
study was conducted by considering several solid waste disposal sites based on three methods; observation,
questionnaire survey and microbiological analysis. Based on observation method, several solid waste practices
were detected including collection of wastes using trucks, wheel barrow, carriers made from elephant grasses
and cement bags. Questionnaire survey pinpointed several diseases caused by solid wastes such as malaria,
diarrhea, dysentery, cholera, typhoid and worm diseases from the respondents. From microbiological analysis,
several pathogenic bacteria were identified from the solid disposal sites. The bacteria with their frequency of
isolation identified were: Salmonella typhimurium (16.7%), Shigella dysenteriae (16.7%), Citrobacter freundii
(8.3%), Citrobacter amalonaticus (8.3%), Aerobacter aerogenes (8.3%), Proteus vulgaris (16.7%), Klebsiella
oxyotoca (8.3%), Klebsiella (8.3%), E.coli (8.3%). Solid waste generated by the daily activities of the people
needs to be properly managed in such a way that it minimizes the risk to the environment and human health.
Inadequate collection and disposal of solid waste is a major factor in the spread of disease and environmental
degradation.Higher Education Students' Loans Board (HESLB) of The United Republic of Tanzania
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
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