1,720,985 research outputs found
Uterus transplantation. An experimental study in the mouse
No full textUterus transplantation is a possible future treatment for uterine factor infertility, which can be either congenital (uterus agenesis/hypoplasia) or acquired (hysterectomy or intrauterine adhesions). The present study represents experiments where an animal model for uterine transplantation was developed and characterized. Initially, a method for heterotopic uterine transplantation in the mouse was developed. The experiments involved syngeneic transplantation of the uterine horn placed alongside the native uterus. Vascular connections were accomplished by end-to-side anastomoses of aorta/aorta and vena cava/vena cava. There was a typical learning curve of the procedure, with the success rate increasing with experience. Histological evaluation showed that the transplanted uterus was well preserved and the blood flow was similar to that of the native uterus. In one animal, embryos were transferred into the transplanted uterus and pregnancy occurred. This is the first time pregnancy has been shown in a transplanted mouse uterus.The model was modified to include a cervical cutaneous stoma of the transplanted uterus and the implantation rate was thereby increased. In a detailed study of pregnancy in the transplanted uteri it was shown that implantation and pregnancy rates were similar to the native uteri of the transplanted animals and to control animals. Furthermore, offspring from transplanted uteri developed normally and were fertile. This study shows that transplanted uteri can harbour pregnancies until term and that offspring develop fully normally in a syngeneic setting. A crucial aspect in organ transplantation is the preservation of the graft ex vivo. To test the tolerance of the uterus to cold ischemia, mouse uteri were removed and kept at 4oC in preservation solution for 24 or 48 h. It was shown that the uterus was well preserved after 24 h and could be transplanted to a donor with preserved functionality, which was proven by the ability to implant embryos and to carry a normal pregnancy. The behaviour of the transplanted murine uterus in an allogeneic setting was tested. Uteri of BALB/c mice were transplanted into C57BL/6 recipients. It was shown that the blood flow in the grafted uteri was reduced already after 2 days with a continuous decrease after that. The transplanted uteri showed slight inflammatory changes at 2 days and after 5 days rejection was obvious. At 10 days severe rejection was seen and after 15 days the transplants were necrotic. The study shows that the time frame for the rejection and the mechanisms for rejection of the uterus are similar to that of other parenchymal organs.In summary, this study has shown that a mouse animal model can be used for experimental studies on uterine transplantation. It shows for the first time pregnancies and normal offspring in a uterus transplantation model. Moreover, the studies show that the uterus is a fairly tolerable organ, which can be preserved for at least 24 h under cold ischemic conditions, and that rejection is similar to that of other transplanted organs
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
Uterus transplantation. An experimental study in the mouse
No full textUterus transplantation is a possible future treatment for uterine factor infertility, which can be either congenital (uterus agenesis/hypoplasia) or acquired (hysterectomy or intrauterine adhesions). The present study represents experiments where an animal model for uterine transplantation was developed and characterized. Initially, a method for heterotopic uterine transplantation in the mouse was developed. The experiments involved syngeneic transplantation of the uterine horn placed alongside the native uterus. Vascular connections were accomplished by end-to-side anastomoses of aorta/aorta and vena cava/vena cava. There was a typical learning curve of the procedure, with the success rate increasing with experience. Histological evaluation showed that the transplanted uterus was well preserved and the blood flow was similar to that of the native uterus. In one animal, embryos were transferred into the transplanted uterus and pregnancy occurred. This is the first time pregnancy has been shown in a transplanted mouse uterus.The model was modified to include a cervical cutaneous stoma of the transplanted uterus and the implantation rate was thereby increased. In a detailed study of pregnancy in the transplanted uteri it was shown that implantation and pregnancy rates were similar to the native uteri of the transplanted animals and to control animals. Furthermore, offspring from transplanted uteri developed normally and were fertile. This study shows that transplanted uteri can harbour pregnancies until term and that offspring develop fully normally in a syngeneic setting. A crucial aspect in organ transplantation is the preservation of the graft ex vivo. To test the tolerance of the uterus to cold ischemia, mouse uteri were removed and kept at 4oC in preservation solution for 24 or 48 h. It was shown that the uterus was well preserved after 24 h and could be transplanted to a donor with preserved functionality, which was proven by the ability to implant embryos and to carry a normal pregnancy. The behaviour of the transplanted murine uterus in an allogeneic setting was tested. Uteri of BALB/c mice were transplanted into C57BL/6 recipients. It was shown that the blood flow in the grafted uteri was reduced already after 2 days with a continuous decrease after that. The transplanted uteri showed slight inflammatory changes at 2 days and after 5 days rejection was obvious. At 10 days severe rejection was seen and after 15 days the transplants were necrotic. The study shows that the time frame for the rejection and the mechanisms for rejection of the uterus are similar to that of other parenchymal organs.In summary, this study has shown that a mouse animal model can be used for experimental studies on uterine transplantation. It shows for the first time pregnancies and normal offspring in a uterus transplantation model. Moreover, the studies show that the uterus is a fairly tolerable organ, which can be preserved for at least 24 h under cold ischemic conditions, and that rejection is similar to that of other transplanted organs
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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