1,721,187 research outputs found
Comparative Pathogenesis of Severe Versus Mild Swine Influenza Virus Infections
No full textVan Reeth, Kristien; Kanobana, Kirezi; Pensaert, Maurice. (1998). Comparative Pathogenesis of Severe Versus Mild Swine Influenza Virus Infections. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/157936
Porcine epidemic diarrhea: A retrospect from Europe and matters of debate
No full textA retrospect is given on the emergence of porcine epidemic diarrhea (PED) during the early seventies inEurope. While, at first, it appeared as a disease affecting feeder pigs, fattening- and adult swine, it lateralso became pathogenic for neonatal and suckling pigs hereby drastically increasing its economic impact.Isolation of the causative virus revealed a new porcine coronavirus, the origin of which has never beenclarified. Pathogenesis studies with the prototype strain CV777 showed severe villous atrophy in neonatalpigs and the virus-animal interactions showed many similarities with transmissible gastro-enteritis virus(TGEV), another porcine coronavirus. Disease patterns in field outbreaks showed muchvariation but,while farm related factors played a role, possible genetic variations of virus strains in Europe have notbeen examined and are thus unknown. CV777 in experimental pigs caused diarrheal disease and mortalityrates similar to those later encountered in Asia and more recently with the “original” US strains eventhough genomic typing of the prototype European strain have shown that it belongs to the S-INDELstrains. In Europe, PED has become endemic during the eighties and nineties and subsequently regressedso that, after 2000, swine populations in many countries have largely become seronegative. Sporadicoutbreaks have recently reappeared showing a large variety of clinical outcomes
The cell-associated spread of Aujeszky's disease virus (pseudorabies virus) and its possible role in vaccinated sows
No full textPathogenesis of porcine circovirus 2 infections in pigs from foetal to early postnatal life
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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
Differences in virulence between white spot syndrome virus (WSSV) isolates and testing of some control strategies in WSSV infected shrimp
Get PDFWhite spot syndrome virus (WSSV) is a fatal pathogen of shrimp. In this thesis, differences in virulence of WSSV isolates and control strategies against WSSV infection in Penaeus vannamei juvenile, including treatment with cidofovir an antiviral, feeding a diet supplemented with Spirulina platensis and exposure to high water temperature (33°C), were evaluated. In all experiments shrimp were inoculated intramuscularly or orally with a standardized protocol using a fixed WSSV infectious titre. Virulence was compared between three WSSV isolates based on time of onset of mortality and time to reach a cumulative mortality of 50 and 100%. Quantification of WSSV infected cells (VP28 positive) in tissues with an important role in shrimp physiology including gills, stomach cuticular epithelium, cuticular epithelium of the body wall, hematopoietic tissues and antennal glands was done to find the basis of differences in virulence. Mortality started at 36 h post inoculation (hpi) in shrimp inoculated with two Thai isolates and 36-60 hpi with the Viet isolate. Cumulative mortalities reached 100% at 72-84, 108 and 204-348 hpi with WSSV Thai-1, WSSV Thai-2 and WSSV Viet, respectively. The mean numbers of infected cells were significantly higher in each examined tissue of naturally deceased shrimp inoculated with a highly virulent WSSV Thai-1 than with the low virulent WSSV Viet isolate except in hematopoietic tissues. The difference was prominent in gills (6x). Cidofovir was not effective in blocking WSSV infection in shrimp, which was in contrast with the results obtained with DNA viruses in man. This could be due to (i) limited cellular uptake, (ii) disability of shrimp cells to metabolize cidofovir in its active form, and/or (iii) differences between WSSV and other DNA viruses. A diet supplemented with S. platensis did not reduce mortality. In this thesis, three water temperatures (27°C, 30°C and 33°C) were tested on the clinical and virological outcome of WSSV infection in shrimp. Two temperatures, 27°C and 30°C were permissive for virus replication, which resulted in disease and mortality of shrimp. At 33°C continuously before and after inoculation or after inoculation only, shrimp did not show clinical signs, mortality was almost absent and virus replication was inhibited. The effect of 33°C was independent of inoculation route and infectious titre used. To explore the potential of 33°C to control white spot syndrome, the impact of 33°C for 6 h, 12 h, 18 h and 24 h per day in shrimp infected with a high dose of WSSV Thai-1 or WSSV Viet isolate was investigated. A duration of 33°C for 6 h per day had no beneficial effect. Longer durations (12-24h) were effective to delay and reduce mortality in shrimp inoculated with both isolates. The results with 18 h per day at 33°C broaden the application potential of 33°C to prevent disease and reduce mortality by minimizing the negative effects on shrimp physiology. The effect of increasing temperature from 27°C to 33°C at different stages of WSSV infection (0, 12, 24, 48 and 96 hpi) in shrimp inoculated with a low or a high dose of WSSV Thai-1 or WSSV Viet was examined. Increasing temperature to 33°C was effective in inducing protection only at an early stage of infection (≤ 24 hpi) in shrimp inoculated with each isolate. At a later stage of infection, it had no or even an adverse effect, a sharp rise of mortality. The cause of this sharp rise of mortality could be a combination of progression of infection in tissues and negative effects of 33°C on shrimp physiology such as increased requirement of oxygen and reduced oxygen exchange in gills
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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