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The biosynthetic pathway of actinorhodin in Streptomyces coelicolor A3(2) has been studied for decades as a model system of type II polyketide biosynthesis. The actinorhodin biosynthetic gene cluster includes a gene, actVI-orfA, that encodes a protein that belongs to the nuclear transport factor-2-like (NTF-2-like) superfamily. The function of this ActVI-ORFA protein has been a long-standing question in this field. Several hypothetical functions, including pyran ring cyclase, enzyme complex stability enhancer, and gene transcription regulator, have been proposed for ActVI-ORFA in previous studies. However, although the recent structural analysis of ActVI-ORFA revealed a solvent-accessible cavity, the protein displayed structural differences to the well-characterized cyclase SnoaL and did not possess a DNA-binding domain. The obtained crystal structure facilitates an inspection of the previous hypotheses regarding the function of ActVI-ORFA. In the present study, we investigated the effects of a series of actVI-orfA test plasmids with different mutations in an established vector/host system. Time-course analysis of dynamic metabolism profiles demonstrated that ActVI-ORFA prevented formation of shunt metabolites and may have a metabolic flux directing function, which shepherds the flux of unstable intermediates towards actinorhodin. The expression studies resulted in the isolation and structure elucidation of two new shunt metabolites from the actinorhodin pathway. Next, we utilized computational modeling to probe the active site of ActVI-ORFA and confirmed the importance of residues R76 and H78 in the flux directing functionality by expression studies. This is the first time such a function has been observed for a member of NTF-2-like superfamily in Streptomyces secondary metabolism.

Abstract The use of data and algorithms in the social sciences allows for exciting progress, but also poses epistemological challenges. Operations that appear innocent and purely technical may profoundly influence final results. Researchers working with data can make their process less arbitrary and more accountable by making theoretically grounded methodological choices. We apply this approach to the problem of simplifying networks representing ethnographic corpora, in the interest of visual interpretation. Network nodes represent ethnographic codes, and their edges the co-occurrence of codes in a corpus. We introduce and discuss four techniques to simplify such networks and facilitate visual analysis. We show how the mathematical characteristics of each one are aligned with an identifiable approach in sociology or anthropology: structuralism and post-structuralism; identifying the central concepts in a discourse; and discovering hegemonic and counter-hegemonic clusters of meaning. We then provide an example of how the four techniques complement each other in ethnographic analysis.

This textometric analysis, performed with the TXM software, offers a re-reading of a Franco-Ontarian play where each character is characterized by the language register he uses. The analysis of the lexicon of Michel Ouellette’s play French Town (1994) highlights the peculiarities of the language of Cindy, both in the way she tries to express herself, in her vocabulary and in her way of expressing her emotions. Thus, the “calcul des spécificités” method reveals that the three lexical units with the greatest frequency relate to the character of Cindy and their analysis shows how she manages to express her emotions although she has great difficulties to say I.

Abstract Background Small G proteins, which are essential regulators of multiple cellular functions, are activated by guanine nucleotide exchange factors (GEFs) that stimulate the exchange of the tightly bound GDP nucleotide by GTP. The catalytic domain responsible for nucleotide exchange is in general associated with non-catalytic domains that define the spatio-temporal conditions of activation. In the case of small G proteins of the Arf subfamily, which are major regulators of membrane trafficking, GEFs form a heterogeneous family whose only common characteristic is the well-characterized Sec7 catalytic domain. In contrast, the function of non-catalytic domains and how they regulate/cooperate with the catalytic domain is essentially unknown. Results Based on Sec7-containing sequences from fully-annotated eukaryotic genomes, including our annotation of these sequences from Paramecium, we have investigated the domain architecture of large ArfGEFs of the BIG and GBF subfamilies, which are involved in Golgi traffic. Multiple sequence alignments combined with the analysis of predicted secondary structures, non-structured regions and splicing patterns, identifies five novel non-catalytic structural domains which are common to both subfamilies, revealing that they share a conserved modular organization. We also report a novel ArfGEF subfamily with a domain organization so far unique to alveolates, which we name TBS (TBC-Sec7). Conclusion Our analysis unifies the BIG and GBF subfamilies into a higher order subfamily, which, together with their being the only subfamilies common to all eukaryotes, suggests that they descend from a common ancestor from which species-specific ArfGEFs have subsequently evolved. Our identification of a conserved modular architecture provides a background for future functional investigation of non-catalytic domains.

We propose a mixed methods approach to digital ethnographic research. Treating online conversational environments as communities that ethnographers engage with as in traditional fieldwork, we represent those conversations and the codes made by researchers thereon in network form. We call these networks "semantic social networks" (SSNs), as they incorporate information on social interaction and their meaning as perceived by informants as a group and use methods from network science to visualize these ethnographic data. We present an application of this method to a large online conversation about community provision of health and social care and discuss its potential for mobilizing collective intelligence.

Virtual prototyping is increasingly used by businesses to streamline operations, cut costs, and enhance daily operations. This often includes a variety of modeling techniques among which, complex, black-box models. The path from model development to utilization in applied contexts is yet long. Domain experts need to be convinced of the validity of the models and to trust their predictions. To be used in the field, model capabilities need to be affordable, that is, allow rapid and interactive scenario building, even for non-experts. Complex relations governed by statistical interactions must be unveiled for users to understand unexpected predictions. We propose Interact, a model-agnostic, visual what-if tool for regression problems, supporting (1) the visualization of statistical interactions between features, (2) the creation of interactive what-if scenarios using predictive models, (3) the evaluation of model quality and building trust, and (4) the externalization of knowledge through model explainability. While the approach applies in various industrial contexts, we validate the application purpose and design with a detailed case study and a qualitative user study with engineers in the tire industry. By unraveling statistical interactions between features, the INTERACT tool proves to be useful to increase the transparency of black-box machine learning models. We also reflect on lessons learned concerning the development of visual what-if tools for virtual product development and beyond. [ABSTRACT FROM AUTHOR]

Visualizing social networks, especially an overview emphasizing their structure, i.e., communities and their interconnections, is known to be a challenging problem. In this paper, we present a set of design rationales to build such overview visualizations of social networks and our solution called Jasper. We evaluate its performances against two of the most wide-spread visualization techniques (matrix and node-link diagram) in a human–computer controlled experiment based on community-related tasks. While none of the techniques emerge as the overwhelming winner, Jasper appears to be one of the best methods for each task; a fact sustained by the marks given by the users. Overall, Jasper can be seen as an all-encompassing solution for quickly producing legible and compact overviews of large social networks on a single modern computer.

Le rappeur d’origine anishnabé Samian (Samuel Tremblay) s’inscrit de façon originale au sein de la chanson québécoise, dans le contexte d’un essor de la chanson populaire autochtone avec ses quatre albums : Face à soi-même (2007), Face à la musique (2010), Enfant de la terre (2014) et Le messager (2019). Le parcours de Samian, premier rappeur en langue algonquine et chanteur engagé qui croit au pouvoir des mots, révèle un double engagement, poétique et politique, et témoigne d’un cheminement qui va d’une quête de soi et de la part de son héritage autochtone, vers un appel à un projet de société humaniste et universaliste, toujours guidé par une pratique artistique authentique, inspirée par une spiritualité de plus en plus affirmée.

Le but de cet article est de fournir une première théorie quant à l’existence d’un sentiment de minorisation qui ferait partie de l’expérience des groupes minoritaires et aiderait à comprendre leurs revendications et leur comportement politiques. Il vise aussi à développer cette théorie au contact de la réalité des francophones du Canada en situation minoritaire, qui se définissent eux-mêmes par cette situation plutôt que géographiquement (comme hors Québec). Nous procédons d’abord à partir d’une lecture croisée de l’oeuvre philosophique de Deleuze et Guattari et de celle de Tocqueville, afin de préciser le sens du concept de minorité en relation au pouvoir et hors de la référence à la démographie, puis d’esquisser les contours des sentiments de minorisation et d’égalité. Nous passons ensuite aux travaux contemporains en psychologie sociale portant sur les émotions collectives et les relations intergroupes pour valider et préciser davantage les résultats de cette lecture. Enfin, nous nous tournons vers l’événement du « jeudi noir » de l’Ontario français, quand le gouvernement provincial mit fin à deux institutions assurant les services aux Franco-Ontarien·ne·s, pour examiner la réaction de la population francophone à travers le prisme du sentiment de minorisation. Il ressort de cette étude et de cette catégorisation de sentiments politiques liés à la relation à la norme sociale qu’un sentiment de minorisation peut émerger dans un contexte où un groupe se sent égal ou supérieur aux autres et s’attend à pouvoir participer à la définition de la norme pour la société plus large.

The Personal Librarian for Aboriginal Students (PLAS) program at the University of Alberta (UofA) is a creative outgrowth of the growing Personal Librarian programs in academic libraries, in which a student is partnered with an individual librarian for the academic year. In the case of the UofA's PLAS program, first-year undergraduate students who self-identified as Aboriginal during the registration process were selected as participants. The first year of the program saw many successes. This paper provides background on the initiative and the associated action research indicating a creative approach to engaging Aboriginal students.

A fundamental question in language acquisition research is whether young children have abstract grammatical representations. We tested this question experimentally. French-learning 30-month-olds were first taught novel word-object pairs in the context of a gender-marked determiner (e.g., un[subscript MASC]ravole "a ravole"). Test trials presented the objects side-by-side while one of them was named in new phrases containing other determiners and an adjective (e.g., le[subscript MASC]joli ravole[subscript MASC] "the pretty ravole"). The gender agreement between the new determiner and the nonadjacent noun was manipulated in different test trials (e.g., le[subscript MASC]__ravole[subscript MASC]; *la[subscript FEM]__ravole[subscript MASC]). We found that online comprehension of the named target was facilitated in gender-matched trials but impeded in gender-mismatched trials. That is, children assigned the determiner genders to the novel nouns during word learning. They then processed the non-adjacent gender agreement between the two categories (Det, Noun) during test. The results demonstrate abstract featural representation and grammatical productivity in young children.

Peu de femmes, et surtout peu de poètes, ont pris la parole en Ontario français dans les années 1970, 1980 et même 1990. Au tournant du siècle, de nouvelles voix ont émergé. Parmi elles, Guylaine Tousignant dont le premier recueil de prose poétique, Carnets de déraison (Prise de parole, 2005), met en scène une narratrice qui, malgré sa difficulté à dire « je », dans une parole que l’auteure qualifie de « pluri auto bio graphique », arrive à exprimer son agentivité non pas surtout dans le propos, mais bien dans l’écriture même par la différenciation et l’hybridation génériques, le dédoublement rhétorique du sujet, le recours à différentes stratégies discursives comme le dialogue intérieur et le micro-récit, ainsi que par l’intertextualité. L’écriture s’inscrit d’abord dans l’écrit intime, déjà suggéré par le paratexte. Le texte se déploie en fragments qui permettent l’expression du mouvement de la pensée qui hésite et doute; au point de vue du genre, cette écriture s’avère une hybridation de la poésie, des carnets, du livre de raison, du journal intime et de la confession. Tout au long du récit poétique, le sujet, qui se dédouble, porte un regard critique sur soi, ce qui l’oblige à affirmer son agentivité. Les stratégies discursives permettant cette affirmation de soi vont du dialogue intérieur, avec une mise en scène de l’autre, au micro-récit qui permet de s’inventer des histoires, en passant par un choix de verbes d’action. Quant à la subversion, elle s’inscrit surtout dans l’intertextualité et est donnée d’entrée de jeu par l’exergue de Descartes, puis par l’allusion à Camus. Dans ce recueil, l’écriture constitue le moyen et le lieu d’une quête de soi. Elle permet d’assumer toutes les voix qui obligent le «je» à se remettre en question, à se juger, mais qui construisent pourtant aussi ce «je» comme sujet. En ayant recours à ces stratégies, le texte finit par assumer pleinement le doute comme constitutif de soi mais parvient aussi à affirmer le droit à la déraison. Au bout du compte, c’est le travail de l’écriture qui aura permis au «je» d’affirmer son agentivité.

Smooth words are connected to the Kolakoski sequence. We construct the maximal and the minimal in nite smooth words, with respect to the lexicographical order. The naive algorithm generating them is improved by using a reduction of the De Bruijn graph of their factors. We also study their Lyndon factorizations. Finally, we show that the minimal smooth word over the alphabet f1; 3g belongs to the orbit of the Fibonacci word.