1,721,001 research outputs found
Scientific examination of the Mantegna's paintings in Sant'Andrea, Mantua: the families of Christ and St.John the Baptist and the baptism of Christ
No full textThe attribution of the paintings to Mantegna has been the subject of many controversial discussions among art historians, even though today it seems that, in spite of the fact that the paint surfaces were already badly cleaned and varnished since the beginning of the nineteen century, both paintings can be attributed to the last period of Mantegna’s painting activity.
Therefore, with the purpose to complement the historical studies with the results of scientific examinations, the two paintings have been analysed in situ with the use of non-invasive portable analytical techniques, such as digital multi spectral scanner imaging system and X-Ray Fluorescence. It has been hence possible to evaluate
the state of conservation, study applied artistic technique, distinguish and locate past restoration interventions and analyze colour
and pigments. This has been particularly done by complementing
the chemical information gathered through the use of XRF with
the false-colour IR technique.
The first analytical results seem to confirm that both canvas paintings have been prepared in the usual way with layers of gesso; the contemporary presence of elements such as Fe, Si, Mn and Al can be associated with the use of umber mixed with red ochre pigments.
Mantegna was a supremely confident draughtsman and there
is no evidence in his underdrawings of the use of any aids for
the reproductions of cartoons or the enlargements of studies on paper. Instead, he seems to have drawn directly on the gesso making his
first marks with a brush and very diluted carbon black ink, perhaps guided by a smaller scale sketch on paper. Once the placement of
the main features was settled, Mantegna developed the underdrawing using a darker more pigmented liquid material still applied with a brush and contours were defined with broad, thick and fluent lines which have been also painted at sight. The modelling of forms has been achieved at the level of painted surfaces which seems to be a further indication of Mantegna’s late painting production.
All these features seem to be present in both paintings.
Particular attention was paid to the understanding of the material composition of the flesh paints. In fact, even though their composition resulted to be composed of lead white with different proportions of vermilion, they show different flesh tonalities such
as the case of St Joseph and Zacharias and Christ and St John
in The Families of Christ and St John the Baptist (under the name of Holy Family). To this regard the presence of possible pigment deterioration processes which may have taken place in the past are presented and discussed
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Control of sexually transmitted infections at the level of the female reproductive tract
No full textAu niveau des muqueuses du tractus reproducteur féminin (TRF), de nombreux facteurs de l'environnement déterminent la susceptibilité aux infections sexuellement transmissibles (IST). Ces facteurs incluent le liquide séminal (LS), les coinfections, ou encore la composition du microbiote vaginal (MV) qui peuvent moduler l'inflammation. L'inflammation génitale est peu étudiée dans le cadre de coinfections. En particulier, le phénotype et les fonctions des neutrophiles sont très peu décrits au niveau du TRF. L'objectif de ce projet de thèse était d'étudier l'impact de ces facteurs sur l'inflammation génitale, en analysant le rôle du MV, des populations de neutrophiles et des profils de cytokines sur la susceptibilité aux IST incluant les coinfections Chlamydia trachomatis (CT)/VIH-1 et sur les réponses immunitaires associées. Deux approches complémentaires ont été développées, in vitro et in vivo. In vitro, des cellules épithéliales endocervicales humaines (A2EN) ont été exposées ou non à CT en présence ou non de facteurs de l'environnement du TRF (LS ou bactéries du MV). Le profil cytokinique des surnageants (SN) des différentes conditions a été caractérisé puis l'impact des SN a été testé sur l'infection VIH-1. En parallèle, nous avons étudié l'impact de ces SN sur le phénotype et les fonctions (survie, phagocytose, production de ROS) de neutrophiles humains isolés du sang périphérique. In vivo, les neutrophiles ont été suivis en longitudinal chez 9 femelles macaques cynomolgus, dans le sang et en vaginal au cours de 3 cycles menstruels en parallèle aux profils de cytokines et à la composition du microbiote. Dans une 2nde étude, 12 femelles macaques cynomolgus ont été exposées à CT après modification de leur microbiote vaginal. Ces 2 études ont servi de base pour une 3ème étude dans laquelle 9 femelles macaques cynomolgus ont reçu 1 puis 4 doses de LS en intravaginal, puis elles ont été exposées ou non à CT, en présence ou non de LS. A chaque étape, nous avons analysé différents marqueurs de l'inflammation: neutrophiles et profils de cytokines. Les réponses immunitaires innées et spécifiques ont été étudiées à l'euthanasie en systémique et dans les différents compartiments muqueux du TRF.Résultats in vitro: La présence de bactéries du MV modifie le profil de cytokines induites par l'infection CT des cellules A2EN. La présence de LS inhibe l'infection CT des cellules A2EN. Le profil cytokinique des cellules A2EN infectées par CT dépend de la dilution du LS. Dans les conditions expérimentales testées, les SN des différentes conditions n'ont pas d'impact sur la susceptibilité au VIH-1. En revanche, les SN ont un impact sur l'activation des neutrophiles et l'expression de CD62L. Les SN des différentes conditions ont également un impact sur la survie et la fonction de phagocytose des neutrophiles. Des différences sont observées en terme de survie entre certaines conditions expérimentales et peu de différences en terme de phagocytose. Résultats in vivo: Le cycle menstruel affecte la composition du MV, des profils de cytokines et des populations de neutrophiles au niveau vaginal. Les menstruations induisent un fort niveau d'inflammation. L'exposition des femelles macaques à une faible dose répétée de CT n'entraine pas une infection persistante. L'exposition CT a un impact sur le MV, les profils de cytokines au niveau vaginal, et sur les sous-populations de neutrophiles au niveau sanguin. Une inoculation intravaginale de LS induit une forte inflammation génitale, mais pas des doses répétées de LS. Le LS augmente la présente de NET dans les fluides vaginaux. Le LS modifie la réponse immunitaire à l'infection CT en terme de production de cytokines. En présence de LS, CT induit un recrutement de lymphocytes au niveau vaginal. Conclusion : L'ensemble de ces résultats permet de mieux comprendre le rôle de l'environnement sur l'inflammation au niveau du TRF et les conséquences sur l'acquisition des IST.In the female reproductive tract (FRT) mucosa, many environmental factors determine the susceptibility to sexually transmitted infections (STI), directly or indirectly, by modulating the inflammation. Such factors include the seminal plasma (SP), coinfections, or even the composition of the vaginal microbiota. However, the role of inflammation at the level of FRT is poorly studied in the context of coinfections. Specifically, the phenotypes and functions of neutrophils have poorly been described at the level of the FRT. The objective of this project was to study the impact of these factors on the inflammation in the FRT, by analyzing the role of the vaginal microbiota, neutrophil populations and cytokine profiles on the susceptibility to STI including Chlamydia trachomatis (CT)/HIV-1 coinfections and on the associated immune responses. Two complementary approaches were developed in vitro and in vivo. In vitro, a human endocervical epithelial cell line (A2EN) was exposed or not to CT in the presence or absence of factors from the FRT environment (SP or bacteria from the microbiota). The supernatants (SN) in the different conditions were recovered, their cytokine profile was characterized and their impact was tested on HIV-1 infection. In parallel, the impact of these same SN was studied on the phenotype and functions (survival, phagocytosis, ROS production) of human neutrophils isolated from the peripheral blood. In vivo, neutrophils were monitored longitudinally in 9 female cynomolgus macaques, in the blood and vaginally during 3 menstrual cycles in parallel to the cytokine profils and the composition of the microbiota. In a 2nd study, 12 female cynomolgus macaques were exposed to CT after modification of the vaginal microbiota composition. These 2 studies served as the basis for a third study in which 9 female cynomolgus macaques received 1 then 4 doses of SP intravaginally. After that, they were exposed or not to CT, in the presence or not of SP. At each step, we analyzed different markers of the inflammation: neutrophils and cytokine profiles. Innate and specific immune responses were studied in the blood and in the different mucosal compartments of the FRT. In vitro results: The presence of bacteria from the microbiota modified the profile of cytokines induced by CT infection of A2EN cells. The presence of SP inhibited CT infection of A2EN cells. The cytokine profile of A2EN cells infected with CT depended on the dilution of SP: at low dilutions, the effect of LS dominated, at high dilutions, the effect of CT dominated. In the tested experimental conditions, the SN had no impact on the susceptibility to HIV-1. On the other hand, SN had an impact on neutrophil activation and CD62L expression. Different levels of expression of phenotypic markers were observed depending on the experimental conditions. The SN in the different conditions also impacted neutrophil survival and phagocytosis function. Differences were observed in terms of survival between certain experimental conditions and few differences in terms of phagocytosis. In vivo results: The menstrual cycle affected the composition of the microbiota, cytokine profiles and neutrophil subpopulations in the vagina. Menses induce a high level of inflammation. A repeated CT low dose exposure of female cynomolgus macaques did not result in a persistent infection. CT exposure impacted the microbiota and cytokine profiles in the vagina, and neutrophil populations in the blood. Intravaginal inoculation of SP induced a strong genital inflammation, but not repeated doses of SP. SP increased the presence of NET in vaginal fluids. SP modified the immune response to CT infection in terms of cytokine production. In the presence of SP, CT induces lymphocyte recruitment in the vaginal. Conclusion : Altogether these results allow to better understand the role of the local environment on the FRT inflammation level and the consequences for STI acquisition
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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