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Emergence and persistence of hantavirus in rodent reservoirs: Role of glucocorticoid hormone
No full textRodent-borne hantaviruses have received considerable attention in recent years due to the high mortality rate in humans that their infections cause. Anthropogenic stressors are key factors in the emergence of hantavirus-associated diseases. Urbanization, deforestation, noise pollution, artificial lighting and electromagnetic fields are the most common forms of human impact on the environment. An increased systemic concentration of the immunosuppressive class of steroid hormone glucocorticoid is a frequent consequence of chronic anthropogenic stress. Elevated glucocorticoid levels play a crucial role in modulating immune tolerance of rodents, thereby enabling establishment of the host-pathogen interaction. Glucocorticoids support virus persistence in the reservoir host by activating an organ-specific regulatory response mediated by T regulatory lymphocytes to reduce inflammatory and antiviral responses, principally via production of cytokines interleukin-10 and transforming growth factor-β. In-depth analysis of this mechanism would help to understand how rodents maintain a disease-free condition. This may have implications for a cost-effective intervention strategy against hantavirus and other zoonotic human pathogens
Emergence and persistence of hantavirus in rodent reservoirs role of glucocorticoid hormone /
Get PDFRodent-borne hantaviruses have received considerable attention in recent years due to the high mortality rate in humans that their infections cause. Anthropogenic stressors are key factors in the emergence of hantavirus-associated diseases. Urbanization, deforestation, noise pollution, artificial lighting and electromagnetic fields are the most common forms of human impact on the environment. An increased systemic concentration of the immunosuppressive class of steroid hormone glucocorticoid is a frequent consequence of chronic anthropogenic stress. Elevated glucocorticoid levels play a crucial role in modulating immune tolerance of rodents, thereby enabling establishment of the host-pathogen interaction. Glucocorticoids support virus persistence in the reservoir host by activating an organ-specific regulatory response mediated by T regulatory lymphocytes to reduce inflammatory and antiviral responses, principally via production of cytokines interleukin-10 and transforming growth factor-β. In-depth analysis of this mechanism would help to understand how rodents maintain a disease-free condition. This may have implications for a cost-effective intervention strategy against hantavirus and other zoonotic human pathogens
Understanding the complex relationship between the human pathogen hantavirus and its rodent reservoirs underpins a rational disease control strategy
No full textHantaviruses commonly infect rodents in which they do not cause any significant symptoms of disease. In contrast, humans serve occasionally as a dead-end host when they inadvertently become infected through the bite of an infectious rodent or via contact with its urine, faeces and/or saliva. The virus was first recognized in the 1970s as a cause of severe haemorrhagic fever. The outcome is fatal in up to 50% of cases due to renal or pulmonary failure. At present, there is no preventive or curative treatment. Current research aims to determine the possible role of anthropogenic events in disease outbreaks and to explain how hantaviruses persist in rodent reservoirs. In seeking effective therapies, focus is drawn to the immunity of these natural hosts which permits infection but without causing pathology. If this protective response could be harnessed by artificial means in humans, this may provide a rational basis for vaccine or drug design
Effects of anthropogenic events and viral persistence on rodent reservoirs of hantavirus infection understanding host-pathogen interactions facilitates novel approaches to intervention strategies /
No full textHantaviruses are primarily rodent-borne pathogens which have received considerable attention recently due to their high mortality rates in humans. In order to find the causes of rapid transmission and emergence of hantavirus-associated diseases anthropogenic changes are a priority. These include deforestation, urbanization, noise pollution, light pollution and electromagnetic fields, all of which have been shown to profoundly affect rodent physiology and immunology. Moreover, anthropogenic events promote human-rodent co-habitation and thereby provide a driver to increase rates of transmission and, by extrapolation, levels of infection in humans. Such environmental disruption acts as a chronic stressor to rodents and causes elevated concentrations of glucocorticoids, which are a major class of immunosuppressive hormone. Glucocorticoids are responsible for altering the immune tolerance of rodents, thereby rendering them susceptible to infection. Glucocorticoids induce regulatory T lymphocytes to reduce inflammatory and antiviral responses and to activate regulatory responses, principally through production of the cytokines interleukin-10 and transforming growth factor-β to support viral persistence. In order to develop a low-cost intervention strategy for hantavirus infection consideration should be given to a systemic approach to therapy. This would both aim to achieve a reduction of anthropogenic stressors and to gain a greater understanding of host-pathogen interactions
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
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