1,721,001 research outputs found
Development of a green fluorescent protein reporter for a yeast genotoxicity biosensor
No full textA reporter system, constructed for a laboratory screen for new genes involved in DNA repair in the brewer's yeast Saccharomyces cerevisiae, has been developed for use in a genotoxicity biosensor. The strain produces green fluorescent protein (yEGFP) when DNA damage has occurred. yEGFP is codon optimised for yeasts. The reporter does not respond to chemicals which delay mitosis, and responds appropriately to the genetic regulation of DNA repair. Data is presented which demonstrate strain improvements appropriate to biosensor technology: improved signal to noise ratio, ease of data collection and uncomplicated material handling
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
Optimisation of an aptamer-biosensor to detect C-reactive protein
No full textDissertação de Mestrado, Engenharia Biológica, Faculdade de Engenharia de Recursos Naturais, Universidade do Algarve, 2009A proteína C reactiva (PCR) é um biomarcador de doenças caracterizadas por uma
resposta inflamatória aguda; tais como: doenças coronárias, diabetes mellitus ou
carcinomas. A detecção desta proteína em fluidos corporais, em especial em soro
humano pode ainda determinar risco de desenvolvimento futuro de doenças coronárias
em indivíduos aparentemente saudáveis.
Foi realizado a optimização de um novo biosensor aplicando a técnica de Voltametria
de Pulso Diferencial (DPV). A detecção foi realizada em solução tampão aquosa
utilizando eléctrodos de carbono e o produto enzimático electroactivo da reacção de 1-
naftil fosfato com alcalina fosfatase. Neste trabalho foi optimizado, em solução tampão,
o tempo de incubação e o valor de concentração da alcalina fosfatase conjugada com
streptavidina. As condições finais foram testadas em solução de soro humano livre de
PCR diluído 1:10.
A proteína C-reactiva foi retirada do meio líquido aplicando a técnica de ensaio
imunológica “sandwich”. O ensaio requereu como suporte sólido esferas magnéticas
cobertas por streptavidina e como captores biológicos um aptamero de RNA e um
anticorpo monoclonal, ambos biotinilados.
O tempo optimizado de incubação foi de 10 min e a concentração óptima de fosfatase
alcalina acoplada a streptavidina foi de 0.22U/ml. Estas condições em meio tampão
demonstraram um limite de detecção de pelo menos 0.1mg/l de PCR com um
coeficiente de variação igual a ±14.45%. Para as mesmas condições, mas em soro
humano livre de PCR, o limite de detecção foi de pelo menos 0.5mg/l de concentração
proteica e o coeficiente de variância de ±7.32%.
O biosensor desenvolvido demonstrou elevada exactidão, reprodutibilidade, relativa
sensibilidade e rápida concretização do ensaio quando comparado com outros métodos
de detecção tradicionais. Deste modo o novo biosensor desenvolvido apresenta-se como
um excelente candidato à detecção da PCR no campo do diagnóstico médico.C-reactive protein is a biomarker for diseases where an acute inflammatory response is
present. Examples are coronary disease, diabetes mellitus and cancer. The presence of
the CRP protein in body fluids, especially in serum may also predict risk of future
coronary complications in apparently healthy people.
A new aptamer biosensor based on the electrochemical differential pulse voltammetry
detection method was optimised. The detection was done in solution using screenprinted
carbon electrodes and the properties of the electroactive enzymatic product of 1-
naphytl phosphate with alkaline phosphatase. In this work the optimisation of the time
of incubation and concentration of the alkaline phosphatase enzyme conjugated with
streptavidin was performed in buffer medium and the optimised conditions tested in
CRP-free human serum with a total dilution of 1:10.
The C-reactive protein was captured from the media, using a sandwich immunoassay
technique. The solid phase used for the realisation of the sandwich technique in solution
was magnetic beads covered with streptavidin. The sandwich assay was performed with
an RNA aptamer and a monoclonal antibody, both biotinylated.
The optimised time of incubation was 10 minutes and the optimised concentration of the
streptavidin-alkaline phosphatase conjugate 0.22U/ml. These conditions in buffer
medium showed a detection limit of at least 0.1mg/l of CRP concentration with a mean
of coefficient of variance equal to ±14.45%. For the same conditions in CRP-free
human serum, the detection limit was at least 0.5mg/l of protein concentration and the
coefficient of variance ±7.32%.
The developed aptamer biosensor presented elevated accuracy, reproducibility, relative
sensitivity due to some matrix effects and less consumed laboratory time when
compared with traditional tests. For these reasons the new aptamer biosensor developed
appears to be an excellent candidate to detect CRP in the diagnostic field
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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