1,720,957 research outputs found
Molecular characterization and antigenic prediction of foot-and- mouth disease virus in relation to vaccine improvement in endemic settings in Africa
No full textPhD ThesisFoot-and-mouth disease (FMD) affects all cloven-hoofed livestock
and wildlife, and it is caused by FMD virus (FMDV) that belongs to the
genus Aphthorvirus and family Picornaviridae. The disease threatens
food security and livelihoods across different parts of the world. There
are seven FMDV serotypes (O, A, C, Asia1, SAT1-3), and studies in
southern Africa describe buffalos to be persistently infected reservoirs
of SATs and transmit the viruses to cattle. The FMD control is
challenging and antigenic heterogeneity among field-circulating
strains represents the most significant factor. The field's infinite
variants pose a challenge to the effectiveness of vaccines and
suggests for quick, reliable, and cost-effective methods for obtaining
vaccine improvements relevant information timely. FMD is endemic in
Africa; impacting the livelihoods of pastoral communities, and hinders
the livestock sector by denying access of regional and global lucrative
markets. Currently, the strategies deployed to control FMD in Africa,
especially tropical Africa, are typically fragmented national-level
focused activities with relatively poor outcomes, rather than regionally
coordinated initiatives that have been used on other continents
(South America, Europe) to reduce and even eliminate virus
circulation. Studies have not demonstrated whether the buffalo can
also act as carrier of the EurAsian serotypes O and A occurring in
parts of East Africa. Also the current epidemiological status of the
field circulating strains and their genetic-antigenic characteristics
need to be understood. Also, it was unclear on the main challenges to
FMD control under pastoral dominated and endemic settings in Africa
that has hindered FMD control for decades.
This study investigated field reported outbreaks and clinically health
buffalo of Tanzania to determine the molecular epidemiology of the
circulating field strains between 2018 and 2021, their genetic-
antigenic characteristics, and their evolutionary relationships using
molecular techniques for
FMDV detection, typing,
and
characterization. The seroprevalence of FMDV serotypes O and A in
Tanzania were studied using NSP ELISA for natural infection
screening and typed by Solid phase competitive ELISA (SPCE) assay. Additionally; the B-cell antigenic epitopes of SAT1 types were
mapped by combined publicly available immuno-informatics
tools ranging from those employing propensity scales to the most
recent machine learning and artificial intelligence models, to
maximize the prediction authenticity, on the FMDV type SAT1 VP1
polypeptides from this study and those sourced from global rich
databases.
The study identified three FMDV serotypes (A, O and, SAT1)
circulating in the field as Africa Topotype G-I lineage, EA-2 Topotype,
and Topotype I (NWZ) respectively. This study nucleotide sequences
for serotypes O and SAT1 field strains were analysed categorically,
and the shared percent identities of 92.0-100.0% and 96.9-98.8%
were revealed respectively. The analysed 247 buffalo (37.6%, n =93)
and cattle (58.3%, n =154) NSP ELISA positive serum samples from
livestock-wildlife interface areas of Katavi, Mikumi, Mkomazi, and
Ruaha ecosystems in Tanzania were further analyzed for FMDV
serotype O and A by SPCE. A highest percentage seropositivity (PS)
was revealed (67%, n= 103) and (55%, n= 51) in cattle and buffalo,
whereas FMDV serotype A tested highest (54%, n= 83) and O (25%,
n= 23) for cattle and buffalo sera, respectively. Also, some of the
cattle (36%, n= 56) and buffalo (25%, n= 23) sera tested, showed
evidence of multiple infection with FMDV serotypes O and A. Results
showed that out of the 93 analyzed NSPE positive buffalo samples,
30.1% (28) of CI (19 – 39) had antibodies specific to FMDV Type A.
Also 54.8% (51) of CI (39 – 64) and 24.7% (23) of CI (15 – 33) had
antibodies specific to FMDV type O and those of mixed sero reaction
respectively. Similarly, out of 154 NSPE positive cattle samples
analyzed 53.9% (83) of CI (69 – 98), 66.9% (103) of CI (88 – 118)
and 36.4% (56) of CI (44 – 70) had FMDV antibodies specific to type
A, O, and mixed (O&A) seroreactions respectively. The results of
compared serotype-specific seroreactions statuses revealed higher
percentage for type O across all species, next type A, and the lowest
score for mixed seroreactions. Similarly; at 95% CI, the analyzed
cattle and buffalo NSPE positives expressed higher scores of (41.7%;
20.65%) by (33.6%; 11.34%) and (22.67%; 9.31%) on type O, type A
and mixed seroreactions respectively. Results on Chi-square test of
independence were significant, X2 (df = 4, N = 330) = 31.0876, p =.00001 at p<.05 criteria, indicating a relation between spp difference
and variation in state of FMDV infection rates. The analyzed probang
buffalo samples (n=89) from Serengeti national park using FMDV
serotype O and A specific primers (one-step RT-PCR), 1.2% was
revealed to be FMDV type O. Also, five consensus linear epitopes
(PLE I – V) at positions 3-30, 44-59, 95-112, 134-149, 199-219 with
75%, 88%, 94%, 44 % and 24% of their aa reads conserved were
observed respectively. Additionally; conformational epitopes (PCE I –
VI) at positions 1-26, 82-87, 93-114, 131-149, 175-179, and 201-221
with 53 – 100% conserved were also identified. As the vaccines are
challenged by the rapidly evolving FMDV in the field, the unveiling of
conserved epitope domains is vital for enhancing future FMDV
vaccines long-term effectiveness in the field.
This study has demonstrated FMDV type O infections in buffalo being
the first molecular and serosurvey combined study to be undertaken
on Eurasian FMDV types O and A in cattle and buffalos in Tanzania.
The information generated from this study strengthens knowledge on
FMDV epidemiology in Tanzania and Africa, and thereby contributing
to the progressive control pathway-FMD program through tailored
control initiatives. The unveiled challenges of FMD control amongst
Africa’s diverse pastoral communities’ landscape for triggering
strategical discussions on national and transboundary regional-based
FMD control approaches in Africa.Prof. Mark Rweyemamu the SACID-Director and Prof. Gerald Misinzo the SACIDS-ACE II Project Coordinato
Molecular characterization and antigenic prediction of foot-and- mouth disease virus in relation to vaccine improvement in endemic settings in Africa
No full textPhD ThesisFoot-and-mouth disease (FMD) affects all cloven-hoofed livestock
and wildlife, and it is caused by FMD virus (FMDV) that belongs to the
genus Aphthorvirus and family Picornaviridae. The disease threatens
food security and livelihoods across different parts of the world. There
are seven FMDV serotypes (O, A, C, Asia1, SAT1-3), and studies in
southern Africa describe buffalos to be persistently infected reservoirs
of SATs and transmit the viruses to cattle. The FMD control is
challenging and antigenic heterogeneity among field-circulating
strains represents the most significant factor. The field's infinite
variants pose a challenge to the effectiveness of vaccines and
suggests for quick, reliable, and cost-effective methods for obtaining
vaccine improvements relevant information timely. FMD is endemic in
Africa; impacting the livelihoods of pastoral communities, and hinders
the livestock sector by denying access of regional and global lucrative
markets. Currently, the strategies deployed to control FMD in Africa,
especially tropical Africa, are typically fragmented national-level
focused activities with relatively poor outcomes, rather than regionally
coordinated initiatives that have been used on other continents
(South America, Europe) to reduce and even eliminate virus
circulation. Studies have not demonstrated whether the buffalo can
also act as carrier of the EurAsian serotypes O and A occurring in
parts of East Africa. Also the current epidemiological status of the
field circulating strains and their genetic-antigenic characteristics
need to be understood. Also, it was unclear on the main challenges to
FMD control under pastoral dominated and endemic settings in Africa
that has hindered FMD control for decades.
This study investigated field reported outbreaks and clinically health
buffalo of Tanzania to determine the molecular epidemiology of the
circulating field strains between 2018 and 2021, their genetic-
antigenic characteristics, and their evolutionary relationships using
molecular techniques for
FMDV detection, typing,
and
characterization. The seroprevalence of FMDV serotypes O and A in
Tanzania were studied using NSP ELISA for natural infection
screening and typed by Solid phase competitive ELISA (SPCE) assay. Additionally; the B-cell antigenic epitopes of SAT1 types were
mapped by combined publicly available immuno-informatics
tools ranging from those employing propensity scales to the most
recent machine learning and artificial intelligence models, to
maximize the prediction authenticity, on the FMDV type SAT1 VP1
polypeptides from this study and those sourced from global rich
databases.
The study identified three FMDV serotypes (A, O and, SAT1)
circulating in the field as Africa Topotype G-I lineage, EA-2 Topotype,
and Topotype I (NWZ) respectively. This study nucleotide sequences
for serotypes O and SAT1 field strains were analysed categorically,
and the shared percent identities of 92.0-100.0% and 96.9-98.8%
were revealed respectively. The analysed 247 buffalo (37.6%, n =93)
and cattle (58.3%, n =154) NSP ELISA positive serum samples from
livestock-wildlife interface areas of Katavi, Mikumi, Mkomazi, and
Ruaha ecosystems in Tanzania were further analyzed for FMDV
serotype O and A by SPCE. A highest percentage seropositivity (PS)
was revealed (67%, n= 103) and (55%, n= 51) in cattle and buffalo,
whereas FMDV serotype A tested highest (54%, n= 83) and O (25%,
n= 23) for cattle and buffalo sera, respectively. Also, some of the
cattle (36%, n= 56) and buffalo (25%, n= 23) sera tested, showed
evidence of multiple infection with FMDV serotypes O and A. Results
showed that out of the 93 analyzed NSPE positive buffalo samples,
30.1% (28) of CI (19 – 39) had antibodies specific to FMDV Type A.
Also 54.8% (51) of CI (39 – 64) and 24.7% (23) of CI (15 – 33) had
antibodies specific to FMDV type O and those of mixed sero reaction
respectively. Similarly, out of 154 NSPE positive cattle samples
analyzed 53.9% (83) of CI (69 – 98), 66.9% (103) of CI (88 – 118)
and 36.4% (56) of CI (44 – 70) had FMDV antibodies specific to type
A, O, and mixed (O&A) seroreactions respectively. The results of
compared serotype-specific seroreactions statuses revealed higher
percentage for type O across all species, next type A, and the lowest
score for mixed seroreactions. Similarly; at 95% CI, the analyzed
cattle and buffalo NSPE positives expressed higher scores of (41.7%;
20.65%) by (33.6%; 11.34%) and (22.67%; 9.31%) on type O, type A
and mixed seroreactions respectively. Results on Chi-square test of
independence were significant, X2 (df = 4, N = 330) = 31.0876, p =.00001 at p<.05 criteria, indicating a relation between spp difference
and variation in state of FMDV infection rates. The analyzed probang
buffalo samples (n=89) from Serengeti national park using FMDV
serotype O and A specific primers (one-step RT-PCR), 1.2% was
revealed to be FMDV type O. Also, five consensus linear epitopes
(PLE I – V) at positions 3-30, 44-59, 95-112, 134-149, 199-219 with
75%, 88%, 94%, 44 % and 24% of their aa reads conserved were
observed respectively. Additionally; conformational epitopes (PCE I –
VI) at positions 1-26, 82-87, 93-114, 131-149, 175-179, and 201-221
with 53 – 100% conserved were also identified. As the vaccines are
challenged by the rapidly evolving FMDV in the field, the unveiling of
conserved epitope domains is vital for enhancing future FMDV
vaccines long-term effectiveness in the field.
This study has demonstrated FMDV type O infections in buffalo being
the first molecular and serosurvey combined study to be undertaken
on Eurasian FMDV types O and A in cattle and buffalos in Tanzania.
The information generated from this study strengthens knowledge on
FMDV epidemiology in Tanzania and Africa, and thereby contributing
to the progressive control pathway-FMD program through tailored
control initiatives. The unveiled challenges of FMD control amongst
Africa’s diverse pastoral communities’ landscape for triggering
strategical discussions on national and transboundary regional-based
FMD control approaches in Africa.Prof. Mark Rweyemamu the SACID-Director and Prof. Gerald Misinzo the SACIDS-ACE II Project Coordinato
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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