1,720,972 research outputs found
Automated mass spectrometry-based metabolomics data processing by blind source separation methods
Get PDFUna de les principals limitacions de la metabolòmica és la transformació de dades crues en informació biològica. A
més, la metabolòmica basada en espectrometria de masses genera grans quantitats de dades complexes
caracteritzades per la co-elució de compostos i artefactes experimentals. L'objectiu d'aquesta tesi és desenvolupar
estratègies automatitzades basades en deconvolució cega del senyal per millorar les capacitats dels mètodes
existents que tracten les limitacions de les diferents passes del processament de dades en metabolòmica. L'objectiu
d'aquesta tesi és també desenvolupar eines capaces d'executar el flux de treball del processament de dades en
metabolòmica, que inclou el preprocessament de dades, deconvolució espectral, alineament i identificació. Com a
resultat, tres nous mètodes automàtics per deconvolució espectral basats en deconvolució cega del senyal van ser
desenvolupats. Aquests mètodes van ser inclosos en dues eines computacionals que permeten convertir
automàticament dades crues en informació biològica interpretable i per tant, permeten resoldre hipòtesis biològiques i
adquirir nous coneixements biològics.Una de les principals limitacions de la metabolòmica és la transformació de dades crues en informació biològica. A
més, la metabolòmica basada en espectrometria de masses genera grans quantitats de dades complexes
caracteritzades per la co-elució de compostos i artefactes experimentals. L'objectiu d'aquesta tesi és desenvolupar
estratègies automatitzades basades en deconvolució cega del senyal per millorar les capacitats dels mètodes
existents que tracten les limitacions de les diferents passes del processament de dades en metabolòmica. L'objectiu
d'aquesta tesi és també desenvolupar eines capaces d'executar el flux de treball del processament de dades en
metabolòmica, que inclou el preprocessament de dades, deconvolució espectral, alineament i identificació. Com a
resultat, tres nous mètodes automàtics per deconvolució espectral basats en deconvolució cega del senyal van ser
desenvolupats. Aquests mètodes van ser inclosos en dues eines computacionals que permeten convertir
automàticament dades crues en informació biològica interpretable i per tant, permeten resoldre hipòtesis biològiques i
adquirir nous coneixements biològics.Una de las principales limitaciones de la metabolómica es la transformación de datos crudos en información biológica.
Además, la metabolómica basada en espectrometría de masas genera grandes cantidades de datos complejos
caracterizados por la co-elución de compuestos y artefactos experimentales. El objetivo de esta tesis es desarrollar
estrategias automatizadas basadas en deconvolución ciega de la señal para mejorar las capacidades de los métodos
existentes que tratan las limitaciones de los diferentes pasos del procesamiento de datos en metabolómica. El
objetivo de esta tesis es también desarrollar herramientas capaces de ejecutar el flujo de trabajo del procesamiento
de datos en metabolómica, que incluye el preprocessamiento de datos, deconvolución espectral, alineamiento e
identificación. Como resultado, tres nuevos métodos automáticos para deconvolución espectral basados en
deconvolución ciega de la señal fueron desarrollados. Estos métodos fueron incluidos en dos herramientas
computacionales que permiten convertir automáticamente datos crudos en información biológica interpretable y por lo
tanto, permiten resolver hipótesis biológicas y adquirir nuevos conocimientos biológicos.One of the major bottlenecks in metabolomics is to convert raw data samples into biological interpretable information.
Moreover, mass spectrometry-based metabolomics generates large and complex datasets characterized by co-eluting
compounds and with experimental artifacts. This thesis main objective is to develop automated strategies based on
blind source separation to improve the capabilities of the current methods that tackle the different metabolomics data
processing workflow steps limitations. Also, the objective of this thesis is to develop tools capable of performing the
entire metabolomics workflow for GC--MS, including pre-processing, spectral deconvolution, alignment and
identification. As a result, three new automated methods for spectral deconvolution based on blind source separation
were developed. These methods were embedded into two computation tools able to automatedly convert raw data into
biological interpretable information and thus, allow resolving biological answers and discovering new biological
insights
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
New strategies based on machine learning and cheminformatics for untargeted metabolomics data annotation
No full textEls experiments de metabolómica no dirigida generen entre centenars i milers de senyals iónics de
metabólits;T]a
cerca en biblioteques de referencia és el métode principal pera la identificació de compostos. Ara
bé, només una petita fracció de les senyals detectades s'anoten coma compostos coneguts. Encara que
la disponibilitat de biblioteques i estándards de referencia ha augmentat en els últims anys,
continuen sent insuficients. Aquesta tesi pretén desenvolupar noves estratégies computacionals
basades en métodes d'aprenentatge automátic (ML) i quimioinformática com a alternatives fiables a
les biblioteques en l'anotació metabolómica no dirigida. A més, la tesi pretén aplicar i validar
aquestes estratégies en experiments de metabolómica no dirigida. La tesi es divideix en dues parts
principals. En primer lloc, es va desenvolupar un algorisme denomina! anotació de fragments basada
en estructura (SBFA) pera guiar la identificació de metabólits basant-se en l'anotació de fragments
de la font a nivell MS1 sense utilitzar biblioteques MS/MS de referencia. En segon lloc, es va
avaluar l'ús de models ML pera predir propietats moleculars, com els valors de l'index de retenció
(RI) i la secció transversal de col·lisió (CCS).Los experimentos de metabolómica no dirigida generan entre cientos y miles de señales iónicas de
metabolitos, y la búsqueda en biblio.ecas de referencia es el método principal para la
identificación de compuestos Sin embargo, solo una pequeña fracción de las señales detectadas se
anotan como compuestos conocidos. Aunque la disponibilidad de bibliotecas y estándares de
referencia ha aumentado en los últimos años. siguen siendo insuficientes. Esta tesis pretende
desarrollar nuevas estrategias computacionales basadas en métodos de aprendiza¡e automático (ML) y
quimioinformática como alternativas fiables a las bibliotecas para la anotación de metabolómica no
dirigida. Además, la tesis pretende aplicar y validar estas estrategias en experimentos de
metabolómica no dirigida. La tesis se divide en dos partes principales. En primer lugar, se
desarrolló un algoritmo denominado anotación de fragmentos basada en estructura (SBFA) para guiar
la identificación de metabolitos basándose en la anotación de fragmentos de la fuente a nivel MS1
sin utilizar bitiliotecas MSIMS de referencia.Untargeted metabolomics experiments generate hundreds to thousands ot ion signals trom metabolites,
and reterence
library searching is the primary method for compound identification. However, only a small portion
of the detected signals are annotated as known compounds. Although the availability of reference
libraries and reference standards has increased in recent years, they are still insufficient. This
thesis aims to develop new computational strategies based on machine learning (ML) and
chemoinformatics methods as reliable alternatives to libraries in untargeted metabolomics
annotation. Also, the thesis aims to apply and validate these strategies in untargeted metabolomics
experiments. The thesis is divided into two main parts. First, an algorithm called Structure-based
fragment annotation (SBFA) was developed to guide the identification of metabolites based on the
annotation of in-source fragments al the MS1 leve! without using reference MSIMS librarles.
Second, the use of ML models to predict molecular properties, such as retention index (RI) and
Collision Cross Section (CCS) values, was assessed. A framework for applying these predicted values
for metabolite annotation was provided, which is of special utility in the absence of reference
data
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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