1,720,980 research outputs found
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
Use of Polymerase Chain Reaction Enzyme Linked Oligonucleotide Sorbent Assay (Pcr-Elosa) for Detection of Disease Agents
Full text linkDiagnostic tool comprises one of the vital components in the control of infectious diseases. One of the most common techniques in the diagnosis of infectious disease currently available is the polymerase chain reaction (PCR) because this technique is very sensitive, specific, and rapid. This technique requires an adjunct technique to indicate the formation of the right reaction product. Agarose gel electrophoresis has been the most common technique to visualise the PCR product or amplicon. Enzyme linked oligonucleotide sorbent assay (ELOSA) is an alternative technique which is more sensitive and gives more important identity of the amplicon. This technique can be more than 100 times as sensitive as a gel agarose electrophoresis, and very specific since confirmation of the amplicon is carried out by DNA hibridisation. The capacity of the ELOSA can also be extended to the detection of disease-causal agent at subtype level, or detection of mutation at particular location in a gene. Since the equipment used for ELOSA is similar to that for ELISA (enzyme linked immunosorbent assay), a large number of samples can be accomplished rapidly. As in ELISA, a number of variation can be made in ELOSA depend on the requirement. Nucleotide can be immobilised on the microwell plate either by passive adsorbtion, by first conjugation of nucleotide with biotin then immobilisation on streptavidin-coated microwell plate, or immobilisaion by covalent bonding. The PCR and ELOSA can be performed at separate or in a single tube by first immobilising the PCR primers on the surface of microwell plates. Key words: PCR amplicon, agarose electrophoresis, oligonucleotide immobilisation, DNA hybridisatio
Challenging Efforts to Find African Swine Fever Vaccine
No full textAfrican swine fever (ASF) has been endemic in Indonesia and neighbouring countries. So far, the only reliable measure to eradicate the disease has been the application of strict biosecurity and culling of all infected pigs. This method is not feasible in Indonesia because most pig farms are small with a deficient level of biosecurity. Vaccination would be the most practical control measure, but no vaccine has been available for ASF. The difficulties encountered in developing the ASF vaccine lie in the fact that the ASF virus is very complex, with a sophisticated ability to paralyze the host immune system. ASF virus infects monocytes and macrophages, causing the cells to lose their functions to mount immune responses, further complicating vaccine development. Killed vaccines, even those containing complete structural and non-structural proteins of the virus and fortified with potent adjuvants for both humoral and cellular immune responses, were practically incapable of inducing protective immunity. Subunit vaccines containing recombinant viral proteins have also been developed, but none have provided satisfactory protection even though the vaccine indicates neutralizing antibodies. Live vaccines prepared from naturally low virulent viral strains or by repeated attenuation in cell cultures provided more satisfactory protective immunities than the inactive or subunit vaccines. However, their use in the field had caused severe side effects because the mutant still had residual virulence. Live vaccines prepared by deleting genes that play a role in virulence have been the most promising approach. Several mutants that were no longer virulent but capable of inducing protective immunity have been identified; however, lengthy safety testing is still needed before this vaccine is commercially available
The Role of Point-of-Care Test to Control Highly Pathogenic Avian Influenza in Indonesia
Full text linkRapid diagnosis followed by stamping out protocol has proven to be the most effective means of eradication of Highly Pathogenic Avian Influenza (HPAI) H5N1. The standard of AI tests are PCR and virus isolation, however their results often take times to initiate rapid eradication protocol. For that reason, a point-of-care (POC) test which is a rapid test used at the location of outbreak (where mortality and morbidity of poultry occur), to help field officer for identification of AI. This paper describes several techniques for detection of HPAI H5N1 virus, POC test and principal mechanism of lateral flow immunoassay which has been generally used in POC test. At present, POC test for HPAI H5N1 rather low sensitivity and expensive, therefore, further research is needed to improve its sensitivity of the tool
Effects of Actinobacillus pleuropneumoniae cytotoxins on generation of oxygen radicals by porcine neutrophils
Full text linkCytotoxins produced by Actinobacillus pleuropneumoniae (App) suggested to be the most important pathogenic and virulent factors for this organism. However, the mechanisms on how the cytotoxins contribute to the disease process remain unclear. The purpose of this study is to investigate the effect of the cytotoxins on the oxidative-burst metabolism of porcine neutrophils. In this study, neutrophils were firstly loaded with an oxidative probe dichlorofluorescin diacetate (DCFHDA) then expose to cytotoxins. Cells producing oxygen radicals emitted fluorescence and its intensity was measured with a FACScan flow cytometer. All cytotoxins derived from either App serotypes producing ApxI and ApxII, App serotypes producing ApxII only, or App serotypes producing ApxII and ApxIII were capable of stimulating neutrophils for oxygen-radical generation. However, compared with phorbol myristate acetate (PMA), App cytotoxins were much weaker as stimulants for oxygen radicals. In addition, Apx preparation stimulated an oxidative-burst metabolism of neutrophils at a low, narrow range of Apx doses. At higher doses, the toxins inhibit the oxidative burst metabolism. The effects of cytotoxins produced by App during infection on recruited neutrophils into the lungs are assumed to be comparable to those observed in this in vitro study. Neutrophils, and other host cells, adjacent to the bacteria become lysis due to high toxin concentration, whereas those at some distance to the bacteria produce oxygen radicals which in turn cause tissue damage or necrosis. Key words: Actinobacillus pleuropneumoniae, cytotoxin, Apx, neutrophils, pig, oxygen radical, flow cytometry
Histopathological changes in naive and sensitised goats caused by Sarcoptes scabiei infestation
Full text linkThe purpose of this study is to compare the histopathological changes in naïve and sensitised goats caused by Sarcoptes scabiei infestation. Thirty goats were allocated evenly into 5 groups. Groups 1, 2 and 3 goats were sensitised once, twice and thrice, respectively; whereas groups 4 and 5 were left unsensitised or naïve. Sensitisation was done by infesting the animals with the mite, then 7 week afterwards the animals were completely cured from the mange. After the sensitisation, all, except group 5, goats were infested on both auricles each with approximately 2000 life mites. Biopsies were collected from each group at 2 day then at weekly intervals from 1 to 7 weeks following infestation. The samples were routinely processed, paraffin blocked, and tissue sections were stained with Haematoxyllin and Eosin (H E), Giemsa, Carbol Chromatrope, and Gram’s when indicated. Lesions in the naïve goats developed progressively characterised by thick parakeratotic crusts honeycombed with tunnels containing large number of mites. Lesions in sensitised goats, which were different qualitatively to those in naïve goats, developed rapidly characterised by copious amount of serocellular exudates in and on the surface of the epidermis, and marked oedema and cell infiltrations in the dermis. Dermal infiltration by eosinophils, which was rare in naïve goats, was apparently an important feature in the sensitised goats. Lesions developed in the sensitised goats were interpreted to be the manifestation of cutaneous anaphylaxis. Resistance or protective immunity against mite reinfestation developed in the sensitised goats is supposedly attributed to this anaphylactic responses. Key words: Sarcoptes scabiei, naïve, sensitised, histopathology, eosinophils, cutaneous anaphylaxis, protective immunit
Ingestion of host immunoglobulin by Sarcoptes scabiei
Full text linkScabies is one of the most important diseases in human and veterinary medicine. The available control measures that rely on acaricides are unsustainable, costly and environmentally unfriendly. Vaccination which is supposedly the most attractive alternative control, is sustainable, potentially cheap and environmentally friendly. Recent development in protein biochemistry and recombinant technology have facilitated the development of anti-parasite vaccine which in the past was impossible. One prerequisite for the anti-parasite-vaccine development is that the parasite has to ingest its host immunoglobulin. This study, therefore, was designed to determine whether Sarcoptes scabiei, a non blood-feeding parasite that resides on the avascular cornified layer of the skin, ingest its host immunoglobulin. Sections of routinely processed mites and skin from a mangy goat were probed with peroxidase-conjugated-anti-goat IgG and the immune complex was visualised with diaminobenzidine solution. To determine whether the ingested IgG was still intact or had been fragmented by the proteolytic enzymes, immunoblotting analysis of SDS-PAGE- fractionated proteins extracted from washed mites was performed. Quantification of IgG was done byan Elisa using purified goat IgG as control. This study showed that IgG in the mites confined to the mite’s gut only, and only a fraction of mite population ingested the IgG. The ingested IgG, as shown by immunoblot analysis, was mostly still intact. This study indicates that development of anti-scabies vaccines is reasonable. Key Words: Sarcoptes scabiei, Immunoglobuli
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