1,720,988 research outputs found
Functional and morphological evaluation of canine veins following preservation in different storage media
No full textInjuries of endothelial and smooth muscle cells of autologous vein due to preservation in standard storage media may be responsible for graft failure, The effects of vein preservation with University of Wisconsin solution (UWs) on endothelial and smooth muscle cell function and morphology were compared to the effects of preservation with autologous whole blood (AWE) and normal saline (NS), which are frequently used in cardiovascular surgery. Canine external jugular and common femoral vein segments were preserved in the different solutions at 4 degrees C for 45 min and 24 hr, Rings (4-5 mm in length) from control and preserved veins were evaluated by isometric tension studies at 37 degrees C and by scanning and transmission electron microscopy, Differences between groups were evaluated by Student's t test or Mann-Whitney U test and by analysis of the variance, and considered to be significant at P < 0.05. Sensitivities to norepinephrine (NE) showed that a 45-min vein storage in AWB (5.7 +/- 0.2 mu mol/L) but not in NS (5.8 +/- 0.2 mu mol/L) or UWs (6.5 +/- 0.2 mu mol/L) had a deleterious effect on function of smooth muscle (P < 0.05) when compared to control veins (6.6 +/- 0.2 mu mol/L). Maximum contractile responses and sensitivities to NE were significantly altered (P < 0.05) after 24-hr vein storage in AWE (0.09 +/- 0.02 g/mm(2) and 5.4 +/- 0.07 mu mol/L) and NS (0.12 +/- 0.03 g/mm(2) and 5.6 +/- 0.08 mu mol/L) but not in UWs (0.36 +/- 0.06 g/mm(2) and 6.4 +/- 0.07 mu mol/L). With both storage times, acetylcholine-induced endothelium-dependent maximum relaxations and sensitivities were significantly reduced (P < 0.05) in veins stored in AWB and NS, but not in UWs, compared with controls. Similarly, transmission electron microscopy revealed marked neutrophil migration beneath the intimal surface of vessels and extensive separation and desquamation of endothelial cells with exposure of subendothelial structures in veins stored in AWB and NS, The results suggest that UWs is a suitable storage medium when compared to AWE and NS. (C) 1997 Academic Press
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
Assessment of the Marketing System for Fish Originated from Lake Tana, Ethiopia
No full textThe primary purpose of this research study was to assess marketing system for the fi sh originated
from Lake Tana. Additionall y, efforts have been made to describe the root causes of the
problems facing va rious actors (Fishermen, distributors/retailers and consumers) in the fi sh
marketing system, from production to marketing stage. In order to accomplish research
objectives, two areas i.e. Lake Tana and Addis Ababa were considered, from production and
marketing/selling perspectives, and looking after the operations performed by the three (above
mentioned) actors of the fi sh marketing system. Therefore, data were collected from the
fi shermen in Lake Tana, retailers (bringing the fi sh from the production area to the market), and
consumers in the terminal market (Addis Ababa) specifically, Piazza, Bole and Merkato, being
considered for the purpose of the study, in order to assess the performance of the system and by
describing the practices and problems across the fi sh marketing system from the point of
production ti ll consumption. A total of 225 respondents, constituting producers (31), retailers
(56) and consumers (13 8) were se lected, by using cluster and convenient sampling techniques, to
take part in the study. For the purpose of primary data collection, two self administered
questionnaires were designed and distributed to the respondent retailers and consumers;
however, the researcher administered another category of questionnaire developed for fi sh
producers from the Lake Tana, by himself, as many of the participants were illiterate. The
reported instruments were prepared both in English and the local language (Amharic), to be
fill ed by the respondents in the language preferable to them. Once the data collection stage was
over, collected responses were organized in the form of tables and graphs, by using percentage,
average scores, standard deviations, and Chi-square analysis. Though, the interview data were
interpreted into meaningful facts, highlighting the problems associated with poor performance of
exchange and phys ical functions by the producers and retailers, lack of cooperation among
fi shermen, and no access to timely information about the demand and price of fish in the market,
on the paJ1 of fi shermen from Lake Tana. Altogether, these factors appeared to be making the
fish originated from Lake Tana inferior in quality, expensive in comparison to the fi sh from other
lakes, and unfair prices obtained by the producers
Prevalence of Helicobacter Pylori and Intestinal Parasite and their Associated Risk Factors among School Children at Selam Fire Elementary School in Akaki Kality, Addis Ababa, Ethiopia
No full textBackground: The prevalence of H. pylori infection mainly acquired during childhood and may be persisting throughout life and it has been found high in developing countries; this prevalence is related to low socioeconomic status, and Intestinal parasitic infections are among the major public health problems in Sub-Saharan Africa. Their distribution is mainly associated with poor personal hygiene, environmental sanitation and limited access to clean water. There is limited information on the burden of the H. pylori and intestinal parasites in Ethiopia and this research will address such gap.
Objectives: To assess the prevalence of Helicobacter pylori and intestinal parasite and their associated risk among Elementary School Children.
Methods: A cross sectional study was conducted to determine the burden and risk factors associated of H. pylori and intestinal parasite among in 422 school children. The study was conducted between March to June 2017. Multiple sampling methods were used, to collect the data. The stool samples were tested for intestinal parasite using direct wet mount and concentration techniques and stool antigen test for H. pylori. Information from the laboratory analysis and questionnaires were entered into SPSS version.20 for analysis.
Results: A total of (n=422) students have been participated in this study 55.2 %( n=233/422) 44.8% (n=189/418) were female and male respectively. Age of range (4-18) years, with mean age of 11.16±SD years [95% CI 10.82-11.5], the mean weight of 30.99 ± SD Kg [95 % CI 29.9 -32.08], the mean height 1.36 ± SD m [95% CI 1.34-1.38], Helicobacter pylori antigens were detected in 14.6% (n=61/422) ,and 6%(n=25/189) 8.6%(n=36/233) male and female respectively. Intestinal parasite were detected in 23.7 %( n=100/422), 10.4 %( n=44/189) 13.3 %( n=56/422) male and female respectively. The co-infection for HP and IPI was present in 4.5 %( n=19/422). The age of study subject, educational status/ monthly income status of their family/guardians, overcrowding and some sanitary practice were a risk factor for the development of intestinal parasite and H. pylori infection.
Conclusions: The prevalence of H. pylori infection is 14.6 %, and IPI is 23.7 %, this burden of IPI among school children call mass de-worming which is going on in some schools. Moreover further studies are required to understand the role of HP and IPI on the overall growth of children and school performance
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