Appropriating Play: Examining Twitch.tv as a Commercial Platform

This thesis critically analyzes Twitch.tv, a gaming-oriented, online live-streaming site. Viewing the site as a ‘lean platform’ (Srnicek, 2017), it analyzes many aspects of Twitch’s business operations, including ownership structure, video game industry affiliations, use of data, and the monetization of user activity. This analysis then identifies three major areas of concern arising from these operations: the tendency toward monopolization in the gaming industry and its peripheral activities; the intensification of audience commodification; and, the tendency to turn professional streamers into precarious creative labourers. All of these implications point to a growing need for concerted labour organization. The goal of this thesis is to address gaps in the existing literature about Twitch and to provide a foundation for future critical inquiries into the site

Design of the U2 Experiment Ground Support Equipment

Small satellites and sensor payloads aboard larger spacecraft can benefit from ground support equipment (GSE) which reduces the time and cost of developing and flight qualifying space instruments. User friendly microcomputers and a comprehensive system design make such GSE possible and, due to the availability of high speed processors with real-time operating systems, even sophisticated instruments can be accommodated. This was demonstrated by The Johns Hopkins University / Applied Physics Laboratory (JHU / APL) during its work with the U2 Experiment, part of the Strategic Defense Initiative Office\u27s Delta 181 Mission. The U2 Experiment, an orbiting multi-sensor optical emissions instrument, was designed, built, and tested by The JHU / APL. The instrument required a high data rate and complex command capability. It also required a relatively short design-to-launch time of eighteen months. GSE was built to facilitate the U2 Experiment\u27s data processing and instrument control subsystem development, sensor subsystem integration, functional and environmental testing (both independent of, and united with, the spacecraft intended to carry it into orbit), and the U2 Experiment\u27s flight data retrieval. Important elements of a GSE system include: 1) Sensor stimulation and exact emulation of the experiment and spacecraft interfaces. 2) A compatible data acquisition and control unit. 3) A user-friendly, real-time computer system. The GSE design for the U2 Experiment is described to show how it satisfied these requirements

The role of inducible costimulator in autoimmunity

Le costimulateur inductible (ICOS) est un récepteur costimulatoire des cellules T crucial pour l’immunité humorale. Chez l’humain, une déficience de ICOS est associée à des infections récurrentes dû à des défauts de différentiation des lymphocytes T auxiliaires folliculaires (Tfh) et un manque d’anticorps protecteurs. Paradoxalement, certains patients déficients en ICOS développent des signes d’autoimmunité causés par des autoanticorps. Ces observations sont en accord avec des résultats suggérant que ICOS joue un double rôle dans la promotion des fonctions de cellules T effectrices et de cellules T régulatrices. L’arthrite rhumatoïde (RA) est une maladie autoimmune caractérisée par l’inflammation articulaire et la destruction progressive des os. Dans la première étude présentée au Chapitre 2, nous avons démontré que ICOS est requis pour l’initiation et la maintenance de l’arthrite induite par le collagène (CIA), un modèle murin de la RA. Nous avons démontré que des événements clés de l’initiation de la CIA incluant la production d’anticorps contre le collagène et la prolifération de cellules T inflammatoires sont dépendants de la voie de signalisation ICOS-PI3K. Aussi, nous avons trouvé que la signalisation par ICOS-PI3K promouvoit le maintien de la CIA. De plus, nous avons établi que l’inhibition de la glycolyse réduit la sévérité de la CIA, ce qui suggère un chevauchement entre la signalisation ICOS-PI3K et le métabolisme du glucose dans la pathogenèse de l’arthrite autoimmune. Dans la deuxième étude présentée au Chapitre 3, nous avons utilisé des souris dont les cellules T régulatrices sont déficientes en ICOS (ICOS FC) pour évaluer l’impact de ICOS dans les cellules Tfr. Nous avons trouvé que les souris ICOS FC possèdent un taux réduit de cellules Tfr, mais aucune diminution des cellules T régulatrices (Treg) précurseurs. De plus, les souris ICOS FC ont un taux élevé de cellules B du centre germinatif (GC) non-spécifiques ainsi qu’une production accrue d’anticorps anti-nucléaires. Nous avons aussi observé une perturbation des réponses anti-virales et de la production d’anticorps spécifiques dans les souris ICOS FC ce qui suggère des rôles non-régulateurs pour les cellules Tfr. Nous avons effectué une analyse de transcriptome de cellule unique avec des Tregs et nous avons observé une accumulation de précurseurs de Tfr dans les souris ICOS FC, ce qui suggère un défaut de la transition Treg à Tfr. Nos données suggèrent que ICOS participe à la différentiation des cellules Tfr en régulant KLF2 et NFAT2, ce qui contribue à l’établissement de traits folliculaires. En résumé, nous avons démontré que ICOS promouvoit le développement de l’arthrite autoimmune en soutenant les fonctions des cellules T inflammatoires par la voie de signalisation ICOS-PI3K. De plus, nos résultats prouvent que ICOS peut prévenir la production d’autoanticorps en supportant la différentiation des cellules Tfr. Notre travail contribue à l’avancement des connaissances en ce qui concerne le rôle double de ICOS dans l’immunité cellulaire et humorale et fournit des paramètres importants à considérer lors de la recherche de nouvelles cibles thérapeutiques.The inducible costimulator (ICOS) is a T cell costimulatory receptor crucial for humoral immunity. In humans, ICOS deficiency is associated with recurrent infections due to defects in T follicular helper (Tfh) differentiation and lack of protective antibodies. Paradoxically, some ICOS-deficient patients were found to exhibit signs of antibody-mediated autoimmunity. These observations are congruent with findings suggesting that ICOS plays a dual role in promoting T effector and T regulatory cell functions. Due to this ambivalence, the role of ICOS in autoimmunity remains unresolved. Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation and progressive bone destruction. The number of ICOS+ T cells in the synovial tissues of RA patients was found to be elevated, suggesting a potential involvement of ICOS signaling in the pathogenesis of RA. In the first study presented in Chapter 2, we showed that ICOS is required for the initiation and maintenance of collagen-induced arthritis (CIA), a murine model of RA. We found that key CIA initiation events such as anti-collagen antibody production and inflammatory T cell proliferation were dependent on ICOS-PI3K signaling. Further, we found that ICOS-PI3K signaling promotes maintenance of established CIA. Additionally, we show that glycolysis inhibition ameliorates CIA, thus suggesting potential overlaps between ICOS-PI3K signaling and glucose metabolism in the pathophysiology of autoimmune arthritis. The initiation of autoimmunity depends on the action of autoimmune effector cells, but also on a failure of regulatory cells. Amongst the latter, T follicular regulatory (Tfr) cells are thought to prevent autoantibody production. In the second study presented in Chapter 3, we used regulatory T cell-specific ICOS knockout (ICOS FC) mice to investigate the impact of ICOS signaling in Tfr cells. We found that ICOS FC mice display a significant reduction in Tfr cell numbers, but no depletion of their T regulatory (Treg) precursors. Further, ICOS FC mice exhibited a rise of extraneous germinal center (GC) B cells numbers and increased production of anti-nuclear antibodies. We also observed disruptions of anti-viral responses and antigen-specific antibody production in ICOS FC mice, suggesting non-regulatory roles for Tfr cells. We performed single-cell transcriptome analysis of regulatory T cells and observed an accumulation of Tfr precursors in ICOS FC mice suggestive of a Treg-to-Tfr transition defect. Mechanistically, we found that ICOS participates in Tfr differentiation by regulating KLF2 and NFAT2, thereby contributing to the establishment of follicular T cell traits. In sum, we demonstrate that ICOS promotes the development of autoimmune arthritis by fostering inflammatory T cell responses in a PI3K-dependent manner. In addition, our work shows that ICOS can prevent autoantibody production by supporting Tfr differentiation. Thus, we contribute insights into the dual role of ICOS in the cellular and humoral arms of autoimmunity, providing important parameters to be considered when searching for novel therapeutic targets

Behavioral response to ultrasound stimulation and tympanal characterization of Megacephela carolina carolina L. (Coloeptera : carabidae)

M.S

An analysis of a preemphasis-deemphasis technique for LCRU television

Analysis of preemphasis-deemphasis technique for LCRU television system providing link between lunar astronaut and MSF

Separable Attentional Predictors of Language Outcome

This is the peer reviewed version of the following article: Salley, B., Panneton, R. K. and Colombo, J. (2013), Separable Attentional Predictors of Language Outcome. Infancy, 18: 462–489. doi:10.1111/j.1532-7078.2012.00138.x, which has been published in final form at http://doi.org/10.1111/j.1532-7078.2012.00138.x. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The aim of this study was to examine the combined influences of infants attention and use of social cues in the prediction of their language outcomes. This longitudinal study measured infants' visual attention on a distractibility task (11 months), joint attention (14 months), and language outcomes (word –object association, 14 months; MBCDI vocabulary size and multi-word productions at 18 months of age). Path analyses were conducted for two different language outcomes. The analysis for vocabulary revealed unique direct prediction from infants' visual attention on a distractibility task (i.e., maintaining attention to a target event in the presence of competing events) and joint attention (i.e., more frequent response to tester's bids for attention) for larger vocabulary size at outcome; this model accounted for 48% of variance in vocabulary, after controlling for baseline communication status (assessed at 11 months). The analysis for multi-word productions yielded direct effects for infants' distractibility, but not joint attention; this model accounted for 45% of variance in multi-word productions, again after controlling for baseline communication status. Indirect effects were not significant in either model. Results are discussed in light of the unique predictive role of attentional factors and social/attention cues for emerging language

Bien manger en 2015 : perception du concept par des adultes clés agissant auprès d’enfants d’âge préscolaire au Québec

Contexte Le concept de saine alimentation est, en 2015, empreint de confusion. La complexité de ce construit est un frein à l’adoption de saines habitudes alimentaires. Les perceptions associées à ce concept qu’ont les parents et le personnel des services de garde influencent le comportement alimentaire des enfants avec qui ils sont en relation. Les comportements alimentaires des enfants de moins de 5 ans sont d’intérêt car ils ont de fortes chances d’être maintenus tout au long de la vie. Des actions ont été mises en place au cours des dernières années auprès de ces cibles afin d’améliorer leurs pratiques alimentaires. Objectifs Explorer ce que signifie bien manger pour des parents d’enfants d’âge préscolaire, des éducatrices et des responsables de l’alimentation (RA) en milieu de garde au Québec en 2015. Méthode Dans le cadre d’un sondage électronique mené auprès de la population cible, une question ouverte est posée en lien avec les perceptions du « bien manger ». Les réponses qualitatives générées par ce sondage sont analysées selon une approche déductive et inductive avec une grille de codification ainsi que des tests statistiques. Résultats La variété est le sous-thème le plus fréquent parmi les 1753 parents alors que la santé prend la première place parmi les 1055 éducatrices et les 267 RA. Les qualités organoleptiques sont surtout abordées par les RA, alors que les références aux signaux de faim et de satiété se démarquent chez les éducatrices. En général, tous les intervenants font mention de concepts reliés au « bien manger » incluant la variété, la saine alimentation, l’équilibre, la modération ou le plaisir. Conclusion Ce portrait représente les perceptions du « bien manger » qu’ont des acteurs clés auprès d’enfants de 2 à 5 ans en 2015. Ces informations sont utiles pour développer des stratégies de communication rejoignant ces cibles afin de favoriser l’adoption de saines habitudes alimentaires. Les cadres de référence et guides gouvernementaux ont un rôle important dans les recommandations qu’ils intègrent, lesquelles sont reprises par les professionnels actifs en développement de saines habitudes de vie à la petite enfance.Context There is confusion surronding the concept of healthy eating in 2015. The complexity of this construct is a barrier to adopting healthy eating habits. The perceptions of this concept that have parents and caregivers influence the eating behavior of the children with whom they interact. Eating behaviors of children under five are of interest because they are likely to be maintained throughout life. Actions have been established in recent years to improve the dietary practices of the target population. Objectives Explore what it means to “eat well” for parents of preschool children, educators and food managers in childcare centers in Quebec in 2015. Methodology As a part of an electronic survey, an open-ended question is asked to the target population in relation to perceptions of "eating well". The qualitative responses generated by this survey are analyzed using a deductive and inductive approach with a coding grid as well as statistical tests. Results Variety is the most common sub-theme among the 1753 parents, while health ranks first among the 1055 educators and the 267 food managers. Organoleptic qualities are mainly addressed by food managers, while mentions of signs of hunger and fullness stand out among the educators. In general, all stakeholders refer to the concepts of "eating well" such as variety, healthy eating, balance, moderation or pleasure. Conclusion This portrait represents the perceptions of “eating well” that key stakeholders with 2 to 5-year old children have in 2015. This information is useful for developing communication strategies that meet these targets in order to promote the adoption of healthy eating habits. Reference frameworks and government guides have an important role regarding the recommendations they provide, which are used by professionals working in developing healthy lifestyles in early childhood