The rules of engagement : what formats, moderators, and news values tell us about the content of electoral debates

U.S. democracy is one of the most inclusive in the world, yet levels of political knowledge and engagement remain markedly low. Moreover, the news media’s coverage of elections inadequately informs and engages the public. These shortcomings underscore the importance of campaign events like electoral debates – events that are designed not only to educate the public but also to provide the public a more active role in the electoral process. Journalistic news norms and values wield tremendous power over campaign news agendas – including post-debate coverage – but the extent to which they influence debate agendas remains unclear. Given what we know about patterns of campaign news coverage, a closer look at mediated debate agendas is warranted. To date, no comprehensive data on debate agendas exist. With a unique sample of debate questions spanning 52 years of electoral campaigns – including general election, primary, and state-level debates – this content analysis is the first of its kind to examine the debate agenda over time and across electoral contexts. This dissertation determines not only the extent to which news norms and routines influence electoral debate agendas but also the conditions (e.g. rules, formats, moderators, question sources) predictive of particular debate questions. In short, this study provides the first systemic insight into what influences the debate agenda and why we should care about the questions posed to the candidates. The findings presented herein suggest that debates are considerably more policy-driven than campaign news coverage; however, content and tone of agendas vary according to format rules, moderator characteristics, and question source. I find that local journalists offer a more substantive and less attack-driven agenda than members of the national press corps; that, contrary to expectations, nonprofit journalists are actually less substantive than commercial press in the debate questions they generate; and public influence through town hall formats does little to help nor hinder the substance of debate agendas. These findings are discussed in a broader democratic context, and the research presented herein offers organizers of these events best practices for future debates and recommendations for preserving their relevance and substance

Coordinate Regulation of G Protein Signaling via Dynamic Interactions of Receptor and GAP

Signal output from receptor–G-protein–effector modules is a dynamic function of the nucleotide exchange activity of the receptor, the GTPase-accelerating activity of GTPase-activating proteins (GAPs), and their interactions. GAPs may inhibit steady-state signaling but may also accelerate deactivation upon removal of stimulus without significantly inhibiting output when the receptor is active. Further, some effectors (e.g., phospholipase C-β) are themselves GAPs, and it is unclear how such effectors can be stimulated by G proteins at the same time as they accelerate G protein deactivation. The multiple combinations of protein–protein associations and interacting regulatory effects that allow such complex behaviors in this system do not permit the usual simplifying assumptions of traditional enzyme kinetics and are uniquely subject to systems-level analysis. We developed a kinetic model for G protein signaling that permits analysis of both interactive and independent G protein binding and regulation by receptor and GAP. We evaluated parameters of the model (all forward and reverse rate constants) by global least-squares fitting to a diverse set of steady-state GTPase measurements in an m1 muscarinic receptor–Gq–phospholipase C-β1 module in which GTPase activities were varied by ∼104-fold. We provide multiple tests to validate the fitted parameter set, which is consistent with results from the few previous pre-steady-state kinetic measurements. Results indicate that (1) GAP potentiates the GDP/GTP exchange activity of the receptor, an activity never before reported; (2) exchange activity of the receptor is biased toward replacement of GDP by GTP; (3) receptor and GAP bind G protein with negative cooperativity when G protein is bound to either GTP or GDP, promoting rapid GAP binding and dissociation; (4) GAP indirectly stabilizes the continuous binding of receptor to G protein during steady-state GTPase hydrolysis, thus further enhancing receptor activity; and (5) receptor accelerates GDP/GTP exchange primarily by opening an otherwise closed nucleotide binding site on the G protein but has minimal effect on affinity (Kassoc = kassoc/kdissoc) of G protein for nucleotide. Model-based simulation explains how GAP activity can accelerate deactivation >10-fold upon removal of agonist but still allow high signal output while the receptor is active. Analysis of GTPase flux through distinct reaction pathways and consequent accumulation of specific GTPase cycle intermediates indicate that, in the presence of a GAP, the receptor remains bound to G protein throughout the GTPase cycle and that GAP binds primarily during the GTP-bound phase. The analysis explains these behaviors and relates them to the specific regulatory phenomena described above. The work also demonstrates the applicability of appropriately data-constrained system-level analysis to signaling networks of this scale

Étude de protéines liant les G-quadruplexes situés en 5’UTR de gènes impliqués dans la maladie de Parkinson

Au sein du système nerveux, les mécanismes de régulation post-transcriptionnelle contribuent grandement aux différents phénotypes cellulaires. En effet, de faibles dérégulations peuvent mener à des maladies. Les G-quadruplexes (G4) d’ARN émergent comme étant de nouveaux acteurs dans la régulation post-transcriptionnelle. Les G4 sont des structures secondaires très stables retrouvées dans l’ADN et l’ARN. Ils sont formés par l’empilement d’un minimum de deux tétrades de guanines et stabilisés par des cations monovalents, habituellement le potassium. Au niveau de l’ARN, ils sont impliqués dans différents mécanismes comme l’épissage alternatif, la polyadénylation alternative, l’activation et l’inhibition de la traduction et la maturation des microARN. Selon plusieurs, les G4 sont considérés comme étant des évènements plutôt que des entités. Des éléments trans, soit des protéines, sont alors en mesure d’assurer leur repliement et dépliement. Une analyse bio-informatique a confirmé un enrichissement de G4 d’ARN dans les transcrits du système nerveux. Cette analyse a aussi permis d’identifier la maladie de Parkinson comme l’une des maladies ayant la plus grande proportion de potentiel G4 (pG4). En effet, sur 16 gènes reliés à la maladie, 15 d’entre eux contiennent au moins un pG4. Ensuite, différentes techniques biochimiques comme des essais de fluorescence, le dichroïsme circulaire et la cartographie in-line ont été utilisées pour confirmer la formation de certains G4 situés dans des régions 5’ non traduites (5’UTR). Ces techniques ont permis d’identifier 4 nouveaux G4 d’ARN n’ayant jamais été caractérisés auparavant. Par la suite, des essais luciférase ont conclus que deux de ces G4, chez les ARNm de VPS35 et PRKN, ont un effet répresseur sur la traduction. Les protéines pouvant lier ces deux G4 ont ensuite été analysées par spectrométrie de masse. La protéine Guanine Nucleotide-Binding Protein-Like 1 (GNL1) a alors été identifiée comme étant une protéine pouvant lier les deux G4. Finalement, l’interaction entre GNL1 et le G4 de VPS35 et PRKN a été confirmée par des essais de retardement sur gel. En bref, cette étude a permis d’identifier une nouvelle protéine, GNL1, pouvant lier deux nouveaux G-quadruplexes se situant dans le 5'UTR de gènes dérégulés dans la maladie de Parkinson. Une régulation de l’interaction entre GNL1 et les G4 pourrait être une option thérapeutique pour contrer les dérégulations présentes dans la maladie de Parkinson.Within the nervous system, the post-transcriptional regulatory mechanisms contribute to the different cellular phenotypes. Indeed, weak deregulations can lead to diseases. RNA G-quadruplexes (G4) are emerging as new players in post-transcriptional regulation. G4s are very stable secondary structures found in DNA and RNA. They are formed by a minimum of two tetrads of guanines and stabilized by monovalent cations usually potassium. At the RNA level, they are involved in different mechanisms, such as alternative polyadenylation, alternative splicing, activation and inhibition of translation, and maturation of microRNAs. According to many, G4s are seen as events rather than entities. Trans elements, like proteins, are able to ensure their folding and unfolding. A bioinformatic analysis confirmed that there is indeed an enrichment of RNA G4s in the transcripts of the nervous system. This analysis also identified Parkinson's disease as one of the diseases with the highest proportion of potential G4 (pG4). Out of 16 disease-related genes, 15 of them contain a least one pG4. Then, different biochemical techniques such as fluorescence assay, circular dichroism, and in-line probing were used to confirm the formation of G4s located in the different 5’ untranslated regions (5’UTR). These techniques identified 4 new RNA G4s that have never been characterized before. Subsequently, luciferase assays concluded that two of these G4s, in the mRNA of VPS35 and PRKN, have a repressive effect on translation. The proteins capable of binding these two G4s were then identified by mass spectrometry. The protein Guanine Nucleotide-Binding Protein-Like 1 (GNL1) was identified as being a protein capable of binding the two G4s. Finally, the interaction between GNL1 and the G4 from VPS35 and PRKN was confirmed by electrophoretic mobility shift assays. In brief, this study identified a new protein, GNL1, which can bind two new G-quadruplexes located in deregulated genes associated with Parkinson's disease. The regulation of the interaction between GNL1 and the two G4s could be a therapeutic option to counter the deregulations present in Parkinson's disease

Étude du périderme de tubercules de somaclones de pomme de terre plus résistants à la gale commune

La pomme de terre est le 4e légume le plus consommé au monde et se retrouve au premier rang au Canada. D’ailleurs, ce pays est le 12e plus gros producteur de pommes de terre mondialement. Certaines maladies s’attaquent à cette culture de grande importance, comme la gale commune de la pomme de terre. Les meilleures méthodes de contrôle de la maladie sont des méthodes culturales (rotation des cultures, contrôle du pH, etc.) et variétales (culture de variétés naturellement plus résistantes). La bactérie responsable de la maladie, Streptomyces scabiei, synthétise une toxine essentielle pour l’apparition des symptômes, la thaxtomine A. Dans des projets antérieurs du laboratoire de Nathalie Beaudoin, des cals de pommes de terre de la variété Yukon Gold ont été habitués à des concentrations croissantes de thaxtomine A. Certains des somaclones régénérés à partir de ces cals sont plus résistants à la gale commune que la variété parentale. Le périderme de ces derniers a été caractérisé de plusieurs façons. Il a été possible de remarquer que celui-ci contient plus de couches de cellules subérisées que la variété parentale. La subérine induit la production de thaxtomine A par S. scabiei. La subérine contenue dans le périderme des somaclones habitués à la thaxomine A a été extraite et mise en culture avec S. scabiei. La production de thaxtomine A a ensuite été quantifée. Une baisse de production de TA lorsque S. scabiei est en contact avec la subérine extraite des somaclones habitués en comparant avec la subérine extraite de la variété parentale a été mesuré. De plus, il a également été possible de remarquer lors d’analyses par chromatographie en phase gazeuse-spectrométrie de masse (GC-MS) des différences dans la composition de la subérine insoluble des somaclones habitués comparée à la subérine de la variété parentale. Finalement, l’expression de plusieurs gènes reliés à la synthèse de la subérine et à la défense a été testé dans le périderme de mini-tubercules âgés de une à trois semaines. Tous les gènes étudiés ont montré une expression plus grande chez les somaclones habitués comparé à la variété parentale pour au moins une des trois semaines du test. Ces résultats ont pu être corrélés à la plus grande résistance des somaclones habitués à la gale commune. Les résultats de ce projet apportent une meilleure connaissance de la résistance à la gale commune, mais également des pistes pour la recherche de variétés plus résistantes qui pourraient être cultivées à grande échelle

Development of a highly optimized procedure for the discovery of RNA G-quadruplexes by combining several strategies

Abstract : RNA G-quadruplexes (rG4s) are non-canonical secondary structures that are formed by the selfassociation of guanine quartets and that are stabilized by monovalent cations (e.g. potassium). rG4s are key elements in several post-transcriptional regulation mechanisms, including both messenger RNA (mRNA) and microRNA processing, mRNA transport and translation, to name but a few examples. Over the past few years, multiple high-throughput approaches have been developed in order to identify rG4s, including bioinformatic prediction, in vitro assays and af nity capture experiments coupled to RNA sequencing. Each individual approach had its limits, and thus yielded only a fraction of the potential rG4 that are further con rmed (i.e., there is a signi cant level of false positive). This report aims to bene t from the strengths of several existing approaches to identify rG4s with a high potential of being folded in cells. Brie y, rG4s were pulled-down from cell lysates using the biotinylated biomimetic G4 ligand BioTASQ and the sequences thus isolated were then identi ed by RNA sequencing. Then, a novel bioinformatic pipeline that included DESeq2 to identify rG4 enriched transcripts, MACS2 to identify rG4 peaks, rG4-seq to increase rG4 formation probability and G4RNA Screener to detect putative rG4s was performed. This work ow uncovers new rG4 candidates whose rG4-folding was then con rmed in vitro using an array of established biophysical methods. Clearly, this work ow led to the identi cation of novel rG4s in a highly specic and reliable manner

Synthèse diastéréosélective de monofluoroalcènes

Cette thèse traite du développement de nouvelles méthodes de synthèse diastéréosélective de monofluoroalcènes diversement substitués. Le premier chapitre présente la place du fluor dans les molécules organiques et son impact sur leurs propriétés. Ensuite, un résumé des méthodes de synthèse existantes de monofluoroalcènes di- et trisubstitués est présenté. L’introduction se termine par un survol des travaux précurseurs du laboratoire Paquin dans le domaine de la synthèse diastéréosélective de monofluoroalcènes tri- et tétrasubstitués. Le second chapitre présente la séquence de synthèse diastéréosélective des 1,1-diaryle-2-fluoroéthènes. Premièrement, les 1-aryle-1-bromo-2-fluoroéthènes sont générés par une réaction d’addition d’hydrure/élimination à partir des β, β-difluorostyrènes-α-silylés, suivie d’une séquence réactionnelle de bromation/désilicobromation. Pour terminer, un couplage de Suzuki-Miyaura avec une variété d’acides boroniques donne accès aux 1,1-diaryle-2-fluoroéthènes. Le troisième chapitre présente la séquence de synthèse diastéréosélective menant à chacun des isomères cis et trans des dérivés β-fluorostyrènes à partir d’intermédiaires réactionnels communs : les (Z)-1-aryle-2-fluoro-1-(triméthylsilyl)éthènes. Les isomères trans sont obtenus par remplacement stéréospécifique du groupement silylé en présence d’eau et de fluorures. Les isomères cis sont accessibles via une séquence de bromation/désilicobromation, suivie par la réduction du nouveau lien C-Br vinylique. Le quatrième chapitre traite d’une nouvelle séquence synthétique permettant la préparation de dérivés silylés des 2,2-difluorostyrènes. Cette nouvelle route présente de nombreux avantages sur la route originale, incluant une étendue réactionnelle plus vaste, des rendements plus élevés, une facilité de purification accrue et l’absence de produits secondaires désilylés. Pour conclure, le cinquième chapitre résume les précédents et aborde aussi les perspectives futures découlant de mes travaux.This thesis focuses on the developpement of novel stereoselective methods to access diversely substituted monofluoroalkenes. The first chapter introduces the fluorine atom and its properties when found within organic molecules. Then, a summary of the existing synthetic methods found in the literature for the synthesis of di- and trisubstituted monofluoroalkenes is presented. The last section of the introduction is an overview of the previous work from the Paquin’s group in the field of tri- and tetrasubstituted monofluoroalkene synthesis. The second chapter presents the diastereoselective synthetic sequence leading to 1,1-diaryl-2-fluoroethenes. First, 1-bromo-1-aryl-2-fluoroethenes are generated by an addition of hydride/elimination sequence on α-trialkylsilyl-β, β-difluorostyrenes, followed by a bromination/desilicobromination sequence. The last step is a Suzuki-Miyaura cross-coupling reaction with various aryl or heteroarylboronic acids, giving access to 1,1-diaryl-2-fluoroethenes. The third chapter describes the diastereoselective synthetic sequences leading to both (Z) and (E)-β-fluorostyrenes from a common intermediate: (Z)-1-aryle-2-fluoro-1-(trialkylsilyl)ethenes. The E isomers are obtained by stereospecific replacement of the silyl group in the presence of a fluoride source and water. The Z isomers are accessible by a bromination/desilicobromination sequence followed by the reduction of a vinylic C-Br bond. The fourth chapter describes a new synthetic sequence allowing the preparation of trialkylsilylated derivatives of 2,2-difluorostyrenes. This new synthetic route shows significant improvements over the original method, including broader reaction scope, ease of purification, and absence of undesirable side-products. To conclude, the fifth chapter summarizes the thesis and opens-up on synthetic perspectives

Architecture-Dependent Noise Discriminates Functionally Analogous Differentiation Circuits

Gene regulatory circuits with different architectures (patterns of regulatory interactions) can generate similar dynamics. This raises the question of why a particular circuit architecture is selected to implement a given cellular process. To investigate this problem, we compared the Bacillus subtilis circuit that regulates differentiation into the competence state to an engineered circuit with an alternative architecture (SynEx) in silico and in vivo. Time-lapse microscopy measurements showed that SynEx cells generated competence dynamics similar to native cells and reconstituted the physiology of differentiation. However, architectural differences between the circuits altered the dynamic distribution of stochastic fluctuations (noise) during circuit operation. This distinction in noise causes functional differences between the circuits by selectively controlling the timing of competence episodes and response of the system to various DNA concentrations. These results reveal a tradeoff between temporal precision and physiological response range that is controlled by distinct noise characteristics of alternative circuit architectures

Willingness of patients with sarcoma to participate in cancer surveillance research: a cross-sectional patient survey

Oncologia ortopèdica; Sarcoma; Estadístiques i mètodes d'investigacióOncología ortopédica; Sarcoma; Estadísticas y métodos de investigaciónOrthopaedic oncology; Sarcoma; Statistics & research methodsObjectives To determine the proportion of patients with extremity sarcoma who would be willing to participate in a clinical trial in which they would be randomised to one of four different postoperative sarcoma surveillance regimens. Additionally, we assessed patients’ perspectives on the burden of cancer care, factors that influence comfort with randomisation and the importance of cancer research. Design Prospective, cross-sectional patient survey. Setting Outpatient sarcoma clinics in Canada, the USA and Spain between May 2017 and April 2020. Survey data were entered into a study-specific database. Participants Patients with extremity sarcoma who had completed definitive treatment from seven clinics across Canada, the USA and Spain. Main outcome measures The proportion of patients with extremity sarcoma who would be willing to participate in a randomised controlled trial (RCT) that evaluates varying postoperative cancer surveillance regimens. Results One hundred thirty complete surveys were obtained. Respondents reported a wide range of burdens related to clinical care and surveillance. The majority of patients (85.5%) responded that they would agree to participate in a cancer surveillance RCT if eligible. The most common reason to participate was that they wanted to help future patients. Those that would decline to participate most commonly reported that participating in research would be too much of a burden for them at a time when they are already feeling overwhelmed. However, most patients agreed that cancer research will help doctors better understand and treat cancer. Conclusions These results demonstrate that most participants would be willing to participate in an RCT that evaluates varying postoperative cancer surveillance regimens. Participants’ motivation for trial participation included altruistic reasons to help future patients and deterrents to trial participation included the overwhelming burden of a cancer diagnosis. These results will help inform the development of patient-centred RCT protocols in sarcoma surveillance research.The institution of the authors has received, during the study period, funding from the McMaster Surgical Associates (MSA) Innovation Grant

The KRESCENT Program (2005-2015) : an evaluation of the state of Kidney Research Training in Canada

Background: The Kidney Research Scientist Core Education and National Training (KRESCENT) Program was launched in 2005 to enhance kidney research capacity in Canada and foster knowledge translation across the 4 themes of health research. Objective: To evaluate the impact of KRESCENT on its major objectives and on the careers of trainees after its first 10 years. Methods: An online survey of trainees (n = 53) who had completed or were enrolled in KRESCENT was conducted in 2015. Information was also obtained from curriculum vitae (CVs). A bibliometric analysis assessed scientific productivity, collaboration, and impact in comparison with unsuccessful applicants to KRESCENT over the same period. The analysis included a comparison of Canadian with international kidney research metrics from 2000 to 2014. Results: Thirty-nine KRESCENT trainees completed the survey (74%), and 44 trainees (83%) submitted CVs. KRESCENT trainees had a high success rate at obtaining grant funding from the Canadian Institutes of Health Research (CIHR; 79%), and 76% of Post-Doctoral Fellows received academic appointments at the Assistant Professor level within 8 months of completing training. The majority of trainees reported that KRESCENT had contributed significantly to their success in securing CIHR funding (90%), and to the creation of knowledge (93%) and development of new methodologies (50%). Bibliometric analysis revealed a small but steady decline in total international kidney research output from 2000 to 2014, as a percentage of all health research, although overall impact of kidney research in Canada increased from 2000-2005 to 2009- 2014 compared with other countries. KRESCENT trainees demonstrated increased productivity, multiauthored papers, impact, and international collaborations after their training, compared with nonfunded applicants. Conclusions: The KRESCENT Program has fostered kidney research career development and contributed to increased capacity, productivity, and collaboration. To further enhance knowledge creation and translation in kidney research in Canada, programs such as KRESCENT should be sustained via long-term funding partnerships.Mise en contexte: Le programme KRESCENT (Kidney Research Scientist Core Education and National Training) a été lancé en 2005 pour augmenter la capacité de la recherche sur les maladies du rein à travers le Canada, et pour encourager la transmission des connaissances au sein des quatre axes de recherche en santé. Objectifs de l’étude: Cette étude avait pour but d’évaluer les répercussions du programme KRESCENT sur ses principaux objectifs ainsi que des retombées sur la carrière des stagiaires participants, dix ans après sa création. Méthodologie: Un sondage en ligne a été mené en 2015 auprès des stagiaires (n = 53) ayant été admis ou ayant complété le programme KRESCENT. Des renseignements ont également été obtenus par la consultation de curriculum vitae (CV). Une analyse bibliométrique a évalué la productivité scientifique et la collaboration des participants ainsi que les répercussions de leur participation à KRESCENT sur leur carrière. Les données de cette analyse ont été comparées à celles des candidats n’ayant pas été retenus au cours de la même période. L’analyse comprenait également une comparaison des données canadiennes avec celles obtenues en recherche sur les maladies du rein ailleurs dans le monde

Effects of blood parasite infection and innate immune genetic diversity on mating patterns in a passerine bird breeding in contrasted habitats

Genetic diversity at immune genes and levels of parasitism are known to affect patterns of (dis)assortative mating in several species. Heterozygote advantage and/or good genes should shape mate choice originating from pathogen/parasite-driven selection at immune genes. However, the stability of these associations, and whether they vary with environmental conditions, are still rarely documented. In this study, we describe mating patterns in a wild population of tree swallows (Tachycineta bicolor) over 4 years and assess the effects of haemosporidian parasite infection and immune genetic diversity at β-defensin genes on those patterns within two habitats of contrasting environmental quality, in southern Québec, Canada. We first show that mating patterns were only very weakly related to individual status of infection by haemosporidian parasites. However, we found a difference between habitats in mating patterns related to infection status, which was likely due to a non-random distribution of individuals, as non-infected mating pairs were more frequent in lower quality habitats. Mating patterns also differed depending on β-defensin heterozygosity at AvBD2, but only for genetic partners outside of the social couple, with heterozygous individuals pairing together. Our study underlines the importance of considering habitat heterogeneity in studies of sexual selection