1,720,962 research outputs found
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
Contrôle du co-repliement d'origamis ADN
No full textDNA origami is a particularly robust technique for designing DNA structures, often on the order of hundreds of nanometers. Introduced in 2006 by Paul Rothemund, this technique relies on the controlled folding of a long scaffold DNA strand (a few thousand nucleotides long), using a set of carefully chosen shorter synthetic strands acting as staples. It is particularly well-suited for designing complex structures in two or three dimensions. However, the size of these DNA origamis is limited by the length of the scaffold strand. Several studies propose assembling identical DNA origamis in multiple steps to achieve larger sizes (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). We have sought to determine whether it is possible to design DNA origamis comprising several identical scaffold strands but each folding differently to form various components of the desired structure. This requires particular work on the design of the origami, but also an understanding of the folding process that leads to its correct assembly. This thesis therefore involves several aspects: exploring algorithmic and geometrical techniques for designing DNA origamis with multiple scaffolds, the experimental implementations associated with these techniques, and modeling the folding and assembly process. In particular, I propose and evaluate several algorithmic methods for selecting a small subset of staples, allowing the pre-formation of the origami scaffolds separately so that they differentiate properly during the final assembly. Furthermore, I explore the usage of this method for assembling frustrated shapes with DNA origami, as well as an alternative differentiation method based on an additional mold origami. My thesis concludes with an ancillary work exploring theoretical and experimental approaches for assembling quasi-crystals with DNA strands algorithmically.L’origami ADN est une technique particulièrement robuste permettant de concevoir des structures en ADN, souvent de l’ordre de la centaine de nanomètres. Introduite en 2006 par Paul Rothemund, cette technique repose sur le repliement contrôlé d’un long brin d’ADN appelé scaffold (de quelques milliers de nucléotides), au moyen d’un ensemble de brins synthétiques plus courts bien choisis, appelés agrafes. Elle se prête particulièrement bien à la conception de structures complexes en deux ou trois dimensions. Cependant, la taille de ces origamis ADN est limitée par la longueur du scaffold. Plusieurs travaux proposent d’assembler en plusieurs étapes un certain nombres d’origamis ADN identiques pour atteindre des tailles supérieures (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). Nous avons, quant à nous, cherché à déterminer s’il était possible de concevoir des origamis ADN comprenant plusieurs brins scaffold identiques mais se repliant de façon différenciée pour former différentes composantes de la structure voulue. Cela nécessite un travail particulier de conception de l’origami, mais également de compréhension du processus de repliement qui mène à son assemblage correct. Cette thèse comporte donc plusieurs aspects : l’exploration des techniques de design d’origamis ADN à plusieurs scaffolds, les réalisations expérimentales associées à ces techniques ainsi qu’une proposition de modélisation du processus de repliement. Je propose notamment une méthode de sélection d’un petit sous-ensemble d’agrafes, permettant de pré-former séparément les scaffolds de l’origami afin qu’ils se différencient convenablement lors de l’assemblage final. J’explore également l’usage de cette méthode pour l’assemblage de formes frustrées en origami ADN, ainsi qu’une méthode alternative de différenciation, basée sur l’utilisation d’un origami supplémentaire comme moule. Je présente enfin un travail annexe explorant les pistes théoriques et expérimentales pour la création de quasi-cristaux en brins d’ADN
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
Contrôle du co-repliement d'origamis ADN
No full textDNA origami is a particularly robust technique for designing DNA structures, often on the order of hundreds of nanometers. Introduced in 2006 by Paul Rothemund, this technique relies on the controlled folding of a long scaffold DNA strand (a few thousand nucleotides long), using a set of carefully chosen shorter synthetic strands acting as staples. It is particularly well-suited for designing complex structures in two or three dimensions. However, the size of these DNA origamis is limited by the length of the scaffold strand. Several studies propose assembling identical DNA origamis in multiple steps to achieve larger sizes (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). We have sought to determine whether it is possible to design DNA origamis comprising several identical scaffold strands but each folding differently to form various components of the desired structure. This requires particular work on the design of the origami, but also an understanding of the folding process that leads to its correct assembly. This thesis therefore involves several aspects: exploring algorithmic and geometrical techniques for designing DNA origamis with multiple scaffolds, the experimental implementations associated with these techniques, and modeling the folding and assembly process. In particular, I propose and evaluate several algorithmic methods for selecting a small subset of staples, allowing the pre-formation of the origami scaffolds separately so that they differentiate properly during the final assembly. Furthermore, I explore the usage of this method for assembling frustrated shapes with DNA origami, as well as an alternative differentiation method based on an additional mold origami. My thesis concludes with an ancillary work exploring theoretical and experimental approaches for assembling quasi-crystals with DNA strands algorithmically.L’origami ADN est une technique particulièrement robuste permettant de concevoir des structures en ADN, souvent de l’ordre de la centaine de nanomètres. Introduite en 2006 par Paul Rothemund, cette technique repose sur le repliement contrôlé d’un long brin d’ADN appelé scaffold (de quelques milliers de nucléotides), au moyen d’un ensemble de brins synthétiques plus courts bien choisis, appelés agrafes. Elle se prête particulièrement bien à la conception de structures complexes en deux ou trois dimensions. Cependant, la taille de ces origamis ADN est limitée par la longueur du scaffold. Plusieurs travaux proposent d’assembler en plusieurs étapes un certain nombres d’origamis ADN identiques pour atteindre des tailles supérieures (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). Nous avons, quant à nous, cherché à déterminer s’il était possible de concevoir des origamis ADN comprenant plusieurs brins scaffold identiques mais se repliant de façon différenciée pour former différentes composantes de la structure voulue. Cela nécessite un travail particulier de conception de l’origami, mais également de compréhension du processus de repliement qui mène à son assemblage correct. Cette thèse comporte donc plusieurs aspects : l’exploration des techniques de design d’origamis ADN à plusieurs scaffolds, les réalisations expérimentales associées à ces techniques ainsi qu’une proposition de modélisation du processus de repliement. Je propose notamment une méthode de sélection d’un petit sous-ensemble d’agrafes, permettant de pré-former séparément les scaffolds de l’origami afin qu’ils se différencient convenablement lors de l’assemblage final. J’explore également l’usage de cette méthode pour l’assemblage de formes frustrées en origami ADN, ainsi qu’une méthode alternative de différenciation, basée sur l’utilisation d’un origami supplémentaire comme moule. Je présente enfin un travail annexe explorant les pistes théoriques et expérimentales pour la création de quasi-cristaux en brins d’ADN
Contrôle du co-repliement d'origamis ADN
No full textDNA origami is a particularly robust technique for designing DNA structures, often on the order of hundreds of nanometers. Introduced in 2006 by Paul Rothemund, this technique relies on the controlled folding of a long scaffold DNA strand (a few thousand nucleotides long), using a set of carefully chosen shorter synthetic strands acting as staples. It is particularly well-suited for designing complex structures in two or three dimensions. However, the size of these DNA origamis is limited by the length of the scaffold strand. Several studies propose assembling identical DNA origamis in multiple steps to achieve larger sizes (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). We have sought to determine whether it is possible to design DNA origamis comprising several identical scaffold strands but each folding differently to form various components of the desired structure. This requires particular work on the design of the origami, but also an understanding of the folding process that leads to its correct assembly. This thesis therefore involves several aspects: exploring algorithmic and geometrical techniques for designing DNA origamis with multiple scaffolds, the experimental implementations associated with these techniques, and modeling the folding and assembly process. In particular, I propose and evaluate several algorithmic methods for selecting a small subset of staples, allowing the pre-formation of the origami scaffolds separately so that they differentiate properly during the final assembly. Furthermore, I explore the usage of this method for assembling frustrated shapes with DNA origami, as well as an alternative differentiation method based on an additional mold origami. My thesis concludes with an ancillary work exploring theoretical and experimental approaches for assembling quasi-crystals with DNA strands algorithmically.L’origami ADN est une technique particulièrement robuste permettant de concevoir des structures en ADN, souvent de l’ordre de la centaine de nanomètres. Introduite en 2006 par Paul Rothemund, cette technique repose sur le repliement contrôlé d’un long brin d’ADN appelé scaffold (de quelques milliers de nucléotides), au moyen d’un ensemble de brins synthétiques plus courts bien choisis, appelés agrafes. Elle se prête particulièrement bien à la conception de structures complexes en deux ou trois dimensions. Cependant, la taille de ces origamis ADN est limitée par la longueur du scaffold. Plusieurs travaux proposent d’assembler en plusieurs étapes un certain nombres d’origamis ADN identiques pour atteindre des tailles supérieures (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). Nous avons, quant à nous, cherché à déterminer s’il était possible de concevoir des origamis ADN comprenant plusieurs brins scaffold identiques mais se repliant de façon différenciée pour former différentes composantes de la structure voulue. Cela nécessite un travail particulier de conception de l’origami, mais également de compréhension du processus de repliement qui mène à son assemblage correct. Cette thèse comporte donc plusieurs aspects : l’exploration des techniques de design d’origamis ADN à plusieurs scaffolds, les réalisations expérimentales associées à ces techniques ainsi qu’une proposition de modélisation du processus de repliement. Je propose notamment une méthode de sélection d’un petit sous-ensemble d’agrafes, permettant de pré-former séparément les scaffolds de l’origami afin qu’ils se différencient convenablement lors de l’assemblage final. J’explore également l’usage de cette méthode pour l’assemblage de formes frustrées en origami ADN, ainsi qu’une méthode alternative de différenciation, basée sur l’utilisation d’un origami supplémentaire comme moule. Je présente enfin un travail annexe explorant les pistes théoriques et expérimentales pour la création de quasi-cristaux en brins d’ADN
Contrôle du co-repliement d'origamis ADN
No full textDNA origami is a particularly robust technique for designing DNA structures, often on the order of hundreds of nanometers. Introduced in 2006 by Paul Rothemund, this technique relies on the controlled folding of a long scaffold DNA strand (a few thousand nucleotides long), using a set of carefully chosen shorter synthetic strands acting as staples. It is particularly well-suited for designing complex structures in two or three dimensions. However, the size of these DNA origamis is limited by the length of the scaffold strand. Several studies propose assembling identical DNA origamis in multiple steps to achieve larger sizes (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). We have sought to determine whether it is possible to design DNA origamis comprising several identical scaffold strands but each folding differently to form various components of the desired structure. This requires particular work on the design of the origami, but also an understanding of the folding process that leads to its correct assembly. This thesis therefore involves several aspects: exploring algorithmic and geometrical techniques for designing DNA origamis with multiple scaffolds, the experimental implementations associated with these techniques, and modeling the folding and assembly process. In particular, I propose and evaluate several algorithmic methods for selecting a small subset of staples, allowing the pre-formation of the origami scaffolds separately so that they differentiate properly during the final assembly. Furthermore, I explore the usage of this method for assembling frustrated shapes with DNA origami, as well as an alternative differentiation method based on an additional mold origami. My thesis concludes with an ancillary work exploring theoretical and experimental approaches for assembling quasi-crystals with DNA strands algorithmically.L’origami ADN est une technique particulièrement robuste permettant de concevoir des structures en ADN, souvent de l’ordre de la centaine de nanomètres. Introduite en 2006 par Paul Rothemund, cette technique repose sur le repliement contrôlé d’un long brin d’ADN appelé scaffold (de quelques milliers de nucléotides), au moyen d’un ensemble de brins synthétiques plus courts bien choisis, appelés agrafes. Elle se prête particulièrement bien à la conception de structures complexes en deux ou trois dimensions. Cependant, la taille de ces origamis ADN est limitée par la longueur du scaffold. Plusieurs travaux proposent d’assembler en plusieurs étapes un certain nombres d’origamis ADN identiques pour atteindre des tailles supérieures (Rajendran et al., 2011, Tikhomirov et al., 2017, Wintersinger et al., 2023). Nous avons, quant à nous, cherché à déterminer s’il était possible de concevoir des origamis ADN comprenant plusieurs brins scaffold identiques mais se repliant de façon différenciée pour former différentes composantes de la structure voulue. Cela nécessite un travail particulier de conception de l’origami, mais également de compréhension du processus de repliement qui mène à son assemblage correct. Cette thèse comporte donc plusieurs aspects : l’exploration des techniques de design d’origamis ADN à plusieurs scaffolds, les réalisations expérimentales associées à ces techniques ainsi qu’une proposition de modélisation du processus de repliement. Je propose notamment une méthode de sélection d’un petit sous-ensemble d’agrafes, permettant de pré-former séparément les scaffolds de l’origami afin qu’ils se différencient convenablement lors de l’assemblage final. J’explore également l’usage de cette méthode pour l’assemblage de formes frustrées en origami ADN, ainsi qu’une méthode alternative de différenciation, basée sur l’utilisation d’un origami supplémentaire comme moule. Je présente enfin un travail annexe explorant les pistes théoriques et expérimentales pour la création de quasi-cristaux en brins d’ADN
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
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
- …
