1,720,978 research outputs found
Peste des petits ruminants virus—in the field and in the host
Get PDFSheep and goats are one of the most important sources of food and income for many people around the world. They are especially important among vulnerable groups in Africa and Asia who may depend solely on them for their livelihood. The disease peste des petits ruminants (PPR) mainly affects domestic sheep and goats, and is caused by the highly contagious PPR virus (PPRV). PPRV is currently the goal of a control and eradication program launched by the Food and Agriculture Organ of the United Nations (FAO) and the World Organization for Animal Health (OIE). This thesis has explored aspects of PPR with the hope of helping the eradication effort. Among other things, the thesis has looked at prevalence and risk factors for PPRV, development of better diagnostic methods, and studied the virus-host interactions.
The prevalence and risk factors for infection among sheep and goats in Tanzania was studied during two years. PPRV circulated with a prevalence of 49.3% in 2014 and 10.0% in 2015. The main risk factors for the animals were being female and increasing age. Interaction with wildlife was also evaluated as a risk factor, but did not lead to increased infection. The transport of serum samples was improved by validating the use of filter papers in a commercial cELISA. By adjusting the cut-off for a positive result, filter papers were a viable option for transport with unreliable cold-chains.
Long transports are also a problem in molecular diagnosis, as the sensitive nucleic acid may degrade. A protocol was developed for a field-adapted full genome sequencing of PPRV. A portable miniPCR and a minION sequencing device, allow analysis at the disease outbreak or in a minimally equipped laboratory. A genetic marker of 255 nucleotides is commonly used for molecular epidemiology, but use of the full genome allows more precise tracing of the infection and viral evolution.
A major symptom of PPR is a severe immunosuppression, mainly produced by the PPRV C and V proteins. The effects of these proteins were studied on the type I and II interferon (IFN) signaling pathways. The V protein was a strong inhibitor of both pathways, whereas the C protein inhibited the type I pathway, but stimulated the type II
Vingelsjuka
Get PDFVingelsjuka är en dödlig sjukdom som drabbar katter och ger symtom från nervsystemet så som beteendeförändringar och ataxi framför allt i bakbenen. Orsaken bakom vingelsjuka visades 1995 av svenska forskare vara bornavirus. Bornasjuka är i Centraleuropa endemiskt hos häst och får och har varit så i flera hundra år, det första fallet av vingelsjuka på katt beskrevs 1974 i Nordisk Veterinärmedicin. Det finns fortfarande mycket okunskap angående vingelsjuka, till exempel smittväg, inkubationstid och påverkan på immunförsvaret. Flera studier har gjorts för att hitta en eventuell reservoar och de som framstått som kandidater är bland annat sorkar och fåglar. Hur smittan sprids från dessa till katter är ännu oklart. Många olika djurarter har visat sig bära på antikroppar mot bornavirus, även människor har testat positivt för antikroppar.
Hur bornavirus interagerar med katters immunförvar är mera utrett och bilden börjar nu klarna något. Katter utvecklar både ett cellmedierat och ett antikroppsmedierat immunförsvar och har visat sig kunna motarbeta infektionen bättre än till exempel hästar
Minor Field study - molekylär epidemiologisk studie för rabies i Sao Paulo state and minas Gerais state, Brasilien
Get PDFRabies is a fatal zoonotic disease spread worldwide. The most common sources of infection
for all animals and humans are bites from dogs or bats. The aim of this degree project was to
diagnose and determine the source of infection for 11 rabies samples from São Paulo State
and Minas Gerais State, Brazil. Diagnosis was made through direct immunofluorescence
assay, mouse inoculation and RT-PCR. The sources of infection were determined by
sequencing 234 nucleotides of the 5’ end of the N-gene and align these with homologous
sequences retrieved from GenBank. All seven samples for which satisfactory sequences could
be achieved clustered with the sequences related to vampire bat with a bootstrap value of
98%.Rabies är en dödlig zoonos som är spridd över hela världen. De vanligaste smittkällorna för
djur och människor är bett från hundar eller fladdermöss. Målet med detta examensarbete var
att diagnostisera och fastställa smittkällan för 11 rabiesprover från São Paulo State och Minas
Gerais State, Brasilien. Diagnos ställdes via direkt immunofluorescens, musinokulering och
RT-PCR. Smittkällan fastställdes via sekvensering av 234 nukleotider av 5´-delen på N-genen
vilka jämfördes med homologa sekvenser hämtade från GenBank. Alla sju prover för vilka
tillfredställande sekvenser gick att uppnå anhopades, med en sannolikhet på 98 %, inom de
sekvenser som relateras till vampyrfladdermusen
Peste des petits ruminants virus—in the field and in the host [Elektronisk resurs]
No full textSheep and goats are one of the most important sources of food and income for many people around the world. They are especially important among vulnerable groups in Africa and Asia who may depend solely on them for their livelihood. The disease peste des petits ruminants (PPR) mainly affects domestic sheep and goats, and is caused by the highly contagious PPR virus (PPRV). PPRV is currently the goal of a control and eradication program launched by the Food and Agriculture Organ of the United Nations (FAO) and the World Organization for Animal Health (OIE). This thesis has explored aspects of PPR with the hope of helping the eradication effort. Among other things, the thesis has looked at prevalence and risk factors for PPRV, development of better diagnostic methods, and studied the virus-host interactions.The prevalence and risk factors for infection among sheep and goats in Tanzania was studied during two years. PPRV circulated with a prevalence of 49.3% in 2014 and 10.0% in 2015. The main risk factors for the animals were being female and increasing age. Interaction with wildlife was also evaluated as a risk factor, but did not lead to increased infection. The transport of serum samples was improved by validating the use of filter papers in a commercial cELISA. By adjusting the cut-off for a positive result, filter papers were a viable option for transport with unreliable cold-chains.Long transports are also a problem in molecular diagnosis, as the sensitive nucleic acid may degrade. A protocol was developed for a field-adapted full genome sequencing of PPRV. A portable miniPCR and a minION sequencing device, allow analysis at the disease outbreak or in a minimally equipped laboratory. A genetic marker of 255 nucleotides is commonly used for molecular epidemiology, but use of the full genome allows more precise tracing of the infection and viral evolution.A major symptom of PPR is a severe immunosuppression, mainly produced by the PPRV C and V proteins. The effects of these proteins were studied on the type I and II interferon (IFN) signaling pathways. The V protein was a strong inhibitor of both pathways, whereas the C protein inhibited the type I pathway, but stimulated the type II.</p
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
Detection of peste des petits ruminants and concurrent secondary diseases in sheep and goats in Ngorongoro district, Tanzania [Elektronisk resurs]
No full textSmall ruminants play an important role in the livelihoods of resource-constrained communities. This study was initiated because of a massive outbreak of a respiratory disease in sheep and goats in Loliondo area in Ngorongoro district of Arusha region in Tanzania in 2016. During flock examination, a total of 240 serum samples and 61 nasal swabs were collected. Antibodies to small ruminant morbillivirus, causative agent of peste des petits ruminants (PPR), were detected from sera using a competitive enzymelinked immunosorbent assay. A multiplex reverse transcription real-time polymerase chain reaction assay was used to detect four pathogens: small ruminant morbillivirus, Mycoplasma capricolum subspecies capripneumoniae, Pasteurella multocida, and Capripoxvirus from the nasal swabs. Overall seroprevalence of PPR was 74.6%, with all four pathogens detected from nasal swabs. Co-infections of small ruminant morbillivirus and Mycoplasma capricolum subspecies capripneumoniae, small ruminant morbillivirus and Capripoxvirus, small ruminant morbillivirus and Pasteurella multocida, and Mycoplasma capricolum subspecies capripneumoniae and Capripoxvirus were also detected. Presence of PPR and the other diseases in this study provided insight into the severity of the outbreak in sheep and goats in Ngorongoro district. Thus, laboratory confirmation is critical for prompt and appropriate interventions to be made for control of diseases in sheep and goats with similar clinical signs. The findings also call for research into development of combined vaccines targeting common diseases of small ruminants in Tanzania
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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