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Rapid detection and quantitation of Bluetongue virus (BTV) using a Molecular Beacon fluorescent probe assay
No full textAbstract
Bluetongue virus (BTV) is the causative agent of Bluetongue (BT) disease in ruminant livestock and occurs almost worldwide between latitudes
35◦S and 50◦N; 24 serotypes of BTV are known of which 8 circulate periodically within parts of the Mediterranean Region. A fast (about 3.5 h)
and versatile diagnostic procedure able to detect and quantify BTV-RNA, has been developed using a Molecular Beacon (MB) fluorescent probe;
PCR primers were designed to target 91 bp within the NS3 conserved region of the viral RNA segment 10 (S10) and bracketed the MB fluorescence
probe hybridisation site. The MB fluorescent probe was used to develop two Bluetongue serogroup-specific assays: a quantitative real time reverse
transcriptase polymerase chain reaction (RT-PCR) and a traditional RT-PCR. These were tested using BTV-RNAs extracted from the blood and
organs of BT-affected animals, and from virus isolate suspensions. The samples included ten serotypes (BTV-1–BTV-9 and BTV-16); of these,
BTV serotypes -1, -2, -4, -9 and -16 have since 1998 been involved in the extensive outbreaks of BT across the Mediterranean Region. To
evaluate the specificity and sensitivity of the MB probe, all positive samples (and negative controls) were tested using the developed quantitative
real time RT-PCR and traditional RT-PCR assays. The former test had a detection limit of 103 cDNA molecules per reaction with a log-linear
quantification range of up to 1011 (R2 = 0.98), while the latter test was able to detect 500 cDNA-BTV molecules/PCR. The results show that the
MB fluorescent probe is both rapid and versatile for the laboratory diagnosis of Bluetongue and for quantifying levels of viraemia in BTV-affected
animals. An “in silico” comparison of the primers and MB fluorescent probe used in this study showed that it is possible to detect all 24 serotypes
of BTV
Diagnosi rapida qualitativa e quantitativa di infezione da Blue Tongue Virus ( BTV) tramite molecular beacon
No full textRelease of platelet-activating factor in human leukemia.
No full textCellular release of platelet-activating factor (PAF) was assessed in a series of human acute and chronic lymphoid and myeloid leukemias at presentation or in an active phase of the disease. PAF-like material, showing physicochemical properties similar to those of synthetic PAF and of PAF released from IgE-sensitized rabbit basophils, was found in cultures of cells from 5 of 6 acute lymphoblastic leukemias (ALL) (2 of 2 T-ALL and 3 of 4 common ALL) and from 13 of 24 B-cell chronic lymphocytic leukemias after stimulation with ionophore A23187 with or without phytohemagglutinin in the presence of acetyl coenzyme A. On the other hand, PAF was released only from 2 of 10 acute myeloblastic leukemias; both of them were of the more mature monoblastic subtype or M5 according to the French-American-British classification. Cells from all three cases of chronic myeloid leukemia studied were also capable of producing PAF. In eight cases of acute lymphoid and myeloid leukemia, the in vivo release of PAF was assessed by testing the plasma levels of this mediator. Only in two cases (one ALL and one acute myeloblastic leukemia) could detectable levels of circulating PAF be demonstrated; it is of interest that both of these cases showed clinical and hematological features of disseminated intravascular coagulation. No PAF was documented in the plasma of the five chronic leukemias tested (four B-cell chronic lymphocytic leukemias and one chronic myeloid leukemia). These findings indicate that lymphoid and myeloid leukemic cells have a different capacity of releasing PAF, possibly related to the level of cell differentiation rather than to an intrinsic property of the neoplastic cells. Furthermore, in some cases, an intravascular release of PAF may occur
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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