The fast-skeletal-muscle-fiber-specific expression of the troponin I(fast) (TnIfast) gene is driven by an Intronic Regulatory Element (IRE) located within the first intron of the gene. The IRE is a 148 bp transcriptional enhancer that contains several known and suspected cis-regulatory elements. These include the E-box, the closely-spaced MEF2 site and CACT box, the CACC site, and the CAGG element. Previous loss-of-function studies performed using the quail TnIfast IRE suggest that its activity depended on the MEF2 and CACT elements. The goal of my thesis research was to determine whether the MEF2 and CACT sites were not only necessary, but also sufficient, to support IRE activity. I prepared head-to-tail multimers of a 27-bp IRE segment that consisted largely of the near-adjacent MEF2 and CACT elements and did not contain any other known/suspected elements. These multimers were cloned upstream of a reporter gene consisting of the minimal promoter of the quail TnIfast gene linked to sequences encoding human placental alkaline phosphatase. The transcriptional capabilities of the constructs were assessed by gene transfer into the mouse soleus muscle in vivo by intramuscular injection/electroporation, and histochemical analysis of reporter enzyme plap expression including quantitative microdensitometry. I found that expression of these constructs was readily detectable and that it was markedly reduced by prior mutation of the CACT and, especially, of the MEF2 sites. These data indicate that the short DNA segment containing MEF2 and CACT elements is sufficient to drive expression in skeletal muscle and confirms the functional importance of these specific elements. / Although constructs containing the wild-type IRE 27-bp region were expressed, there was little preferential expression in fast fibers, in contrast to expression driven by the complete 148-bp IRE. Thus my results indicate that the MEF2 and CACT elements are not sufficient to drive fast fiber-type-specific expression, and suggest that additional elements outside of the 27-bp region tested are also necessary for fiber-type-specificity.

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Introdução: Os músculos da mastigação masseter, temporal, pterigóideo medial e pterigóideo lateral são componentes essenciais do sistema estomatognático. A mastigação decorre da movimentação destes músculos. Além da função fisiológica, os músculos da mastigação estão envolvidos na disfunção temporomandibular (DTM) que é importante causa de dor, sons articulares e função mandibular irregular ou limitada. As DTM representam a maior causa de dor não dental na região orofacial, sendo a causa muscular a mais prevalente. O conhecimento detalhado da composição estrutural e funcional dos músculos da mastigação é fundamental para a compreensão dos mecanismos da DTM muscular. Objetivos: Analisar a distribuição da expressão das isoformas de miosina (rápida e lenta) e, a quantidade de fibras híbridas nos músculos temporal e masseter em material de autópsia da 1a a 9a décadas. Casuística e métodos: Foram estudadas 37 amostras dos músculos temporal e masseter (20 amostras do sexo masculino e 17 do sexo feminino) de autópsias do Serviço de Verificação de Óbitos de São Paulo com intervalo pós-mortem de até 18 horas, de ambos os gêneros e com idades divididas por décadas (1a a 9a décadas). Resultados: Não houve diferença estatística significante na porcentagem de fibras rápidas, lentas e híbridas no músculo masseter e temporal quanto ao gênero, quanto à porcentagem de fibras rápidas e lentas na amostra total e nos grupos de jovens, adultos e idosos. Foi encontrada diferença estatisticamente significante apenas na porcentagem de fibras rápidas do grupo de idosos, onde o masseter apresentou maior número de fibras rápidas. Foi encontrada diferença significante entre os grupos estudados na porcentagem de fibras híbridas no músculo masseter, onde o grupo jovem apresentou mais fibras híbridas do que o adulto e este grupo mais que o grupo idoso. Também houve diferença significante entre os grupos estudados na porcentagem de fibras híbridas no músculo temporal, onde o grupo jovem apresentou mais fibras do que o grupo adulto e idoso. Conclusão: Ao longo das nove décadas a percentagem de fibras lentas foi similar a percentagem de fibras rápidas nos músculos masseter e temporal. Quando a análise foi realizada separadamente comparando-se os músculos masseter e temporal houve diferença estatística (p=0,023*) no grupo idoso com predomínio de fibras rápidas no músculo masseter. Observou-se fibras híbridas presentes desde a primeira década (1 mês de vida) persistindo até a nona década com predomínio no grupo jovem, presença decrescente ao longo das décadas no músculo masseter (p < 0,001*). No músculo temporal observou-se predomínio de fibras híbridas no grupo jovem em relação aos grupos adulto e idoso (p = 0,011*) / Introduction: The masticatory muscles: masseter, temporalis, medial pterygoid and lateral pterygoid are essential components in the estomatognatic system. The mastication occurs through the function of these muscles, which provide direct contact between the upper and inferior arcades. In addition to their fisiologic function, the maticatory muscles are involved in the temporomandibular disfunction (TMD), which is an important cause of the pain, joint sounds and irregular or limited mandibular function .The TMD are seen as a distinct subgroup of reumatologic.and skeletal muscle disorders. They are the main cause of non dental pain in the orofacial area, being the muscular etiology as the most prevalent. The detailed understanding of structural and functional composition of the masticatory muscles is paramount to comprehend TMD due to muscle disorder. Objective: To analyze the muscle fiber type distribution concerning fast and slow myosin expression, and the amount of hybrid fibers in temporalis and masseter muscles in autopsy samples from 1st to 9th decades of age. Casuistics and methods: Tirthy seven temporalis and masseter muscles samples were studied (20 from male and 17 from female) from Serviço de Verificação de Óbitos of São Paulo. The specimens were divided by gender and ages. The samples were collected up to 18 hours post-mortem. Results: The percentage of slow muscle fiber in masseter and temporalis muscles were similar to the percentage of fast muscle fibers, when the samples were analyzed in the totality. However, when they were grouped in three different subgourp of ages: yound, adult and old, elder subjects presented more fast than slow muscle fibers in masseter. There was no significant gender difference in masseter and temporalis muscles concerning fast and slow muscle fiber distribution. Significant difference of hybrid fiber distribution was observed among the young, adult and old groups. Young subjects presented more hybrid fibers than adult, who presented more than elder subjects in masseter. In temporalis, hybrid fibers were more observed within young group than adult or elder group. The presence of hybrid fiber was confirmed with the immunostaining of a single muscle fiber. Conclusion: Slow and fast muscle fiber distribution is similar in both masseter and temporalis muscles in both gender subjects along the nine decades of age. However, when the samples was grouped in three subgroup of ages, fast muscle fibers significantly predominate (p=0.023) in masseter among the old group. Hybrid fibers were observed through out the first to nineth decade of age. The frequency of hybrid fibers decreased significantly (p<0.001) with aging in masseter. In contrast, hybrid fibers were more observed among young than adult or old groups (p=0.011) in temporalis

本文分析近年盛行的電子遊戲實況活動。從分心、不專注於電玩的現象開始，本文以「如何玩」這個提問來引導論證「嬉玩」與「遊戲」這組概念在分析上的效力，藉此，本文論證了電玩實況活動中的心智狀態與活動是游移在電玩活動與嬉鬧互動，在嚴肅遊戲與嬉戲玩耍之間游移，這樣的分神狀態之中也產生了有樂趣、具有實效的遊戲性。 從技術架構的觀點來看，以即時串流的技術為基礎，電玩實況活動結合了即時傳輸與即時互動。使用者所獲致的遊戲聆賞經驗以及互動是即時且與他人同步，便也構成了網路媒介之下的共時經驗，實況中以電玩活動為對象的起鬨也便具共在的實感。本文從聊天室起鬨、技術戲耍挪用等現象中論證了基於遊戲性旨趣的共謀嬉玩。嘲諷、干擾的對抗性是為了製造分神的條件，從中產生張力並獲致遊戲性，而包括實況主在內的所有參與者，皆是在這樣的分神狀態中嬉玩，維繫歡騰的共感情緒。 電子遊戲具有將遊戲性限定在其中的封閉性質，也因此對於電玩的遊戲經驗多有私密、個人的想像，即時串流的電玩實況活動便是打開了這樣的封閉性質。透過網路媒介將人匯聚在遊戲活動周圍，不僅共享了電玩活動本身的樂趣，也在即時串流之下共時的互動跟聆賞經驗中以遊戲為對象群聚嬉戲。這樣的網路活動之所以盛行，顯示了人對遊戲性的需求不僅是來自遊戲中，也來自與他人玩在一起的連結共感，電玩實況便是實現了這樣的需求。 / Taking the prevailing "video game live streaming" activities as research object, this thesis takes "play" and "game" as a set of core concepts, and begins the exploration into their conceptual effect. Setting out the arguments with "How to Play" question, this thesis concludes that the mentality and activities in video game live streaming are in an "in-between" condition. Between video game activity and playful disturbance, seriousness and playfulness, there are gameplay with actual effect. Taking the technical conditions into consideration, video game live streaming consists of live media transportation and live interaction. Users' experiences synchronize with each other, thus contribute to the "togetherness" mediated through the Internet, and also the carnivalistic interactions and disturbance in the live channel. From the fuss and disturbance in the chatroom to the appropriation of streaming "plugins", this thesis argues that these actions conducted by streamer and users contribute to the "distractive" scenario, and the conducts are all based on "the interest of play". Different from serious and immersive mentality which is deemed as the fundamental of playing and gaming, the gameplay in live stream is based on distraction, which is the core condition that brings tension and thus playfulness. All the users in video game live streaming, the streamer included, are connected and forged into a synchronized togetherness by this kind of distractive, carnivalistic playfulness. Digital video games have tributes of enclosure, which require concentration, seriousness and absorption. Video game live streaming opens up this kind of enclosure, and brings people in and around the video game activities. In the live channel, users experience the joy and fun of the game itself together in a synchronized way, and also act on the interest of play, creating distraction and disturbance that bring to playful experiences, and that explains why this kind of Internet activity prevails. This thesis shows that the need of gameplay comes not only from game activities themselves, but also from the desire to "play together". In a digital age, video game live streaming is just the fulfillment of this kind of desire.

Since the inception of Twitch and the early stages of the growth of live streaming, it has been imperative to maintain interactivity between the broadcaster/streamer and the viewers. Interactivity separates live streaming as a media consumption format from traditional media consumption formats such as television or on-demand videos. But due to the exponential growth of Twitch the number of concurrent viewers on streams have increased as well. This higher viewer count decreases interactivity as the chat gets crowded and it is virtually impossible to get your message across to either the streamer or the other viewers. This study investigates how the interactivity can be increased between viewers by categorizing them into smaller sub-communities. The sub-communities in the context of this study mean temporary sub-chats which have a relatively lower number of viewers. There are various factors upon which the categorization of viewers can be decided. During this study three possible approaches were discussed which include categorization based upon an automated topic identification system, manual creation of sub-communities and geo-location categorization. The results indicate that an automated topic identification system that generates temporary sub-communities is a probable solution to increase inter-viewer interactivity and the best approach to implement this feature is the automated approach. The results also state that the hyperpersonal mode of communication encourages viewers to engage more with other viewers, hence it needs to be maintained even after the implementation of the sub-community feature.

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This thesis explores the use of emotes in a synchronous environment where hundreds to thousands of people communicate with each other in different discourse communities. The thesis performs a study on emote use based on the frequencies they are used and their different CMC features in these communities to acquire knowledge on the contextual basis of emote use in synchronous environments. By using various corpus tools and implementing both a quantitative analysis and qualitative analysis, the results show that the frequency of messages that use emotes varies based on the discourse community that is involved in the use of the emotes. The different CMC features are covered by the basis of the discourse community’s behavior, where there is also some involvement based on the size of the different discourse communities on Twitch.

The research in this study aims to investigate the effectiveness of Twitch’s current advertising option, which includes mid-roll, pre-roll, and sponsored streams. It will focus on usefulness of content, brand credibility, purchase intent, and streamer credibility. Twitch has seen a surge in growth and attention in recent years, with an average of 31 million daily visitors and 1.3 trillion minutes watched globally in 2021 alone (Twitch Sales, 2022). However, despite Twitch’s growing popularity as an entertainment and entrepreneurship platform, little research has been conducted on the impact of its advertising options on brand perception. This study seeks to address this gap in literature by examining the effect of mid-roll, pre-roll, and sponsored streams on Twitch’s unique community-driven audience. To achieve this, the study employed a mixed-methods approach, utilizing both quantitative and qualitative data collection methods. First, a pre-survey was administered to participants to gather data on demographics, video game usage, and experience with Twitch.tv. Participants were then shown a 5-minute video containing different types of Twitch ads. After viewing the video, participants completed a post-survey to measure perception of their purchase intent and brand credibility. Overall, the study aims to provide valuable insights for marketers and advertisers looking to leverage the growing popularity of Twitch as an advertising platform.

Today, the video game industry is larger than the sports and film industries combined, and the largest streaming platform Twitch with an average of 2.8 million concurrent viewers offers the possibility for gaming and non-gaming brands to market their products. Estimating streamers’ viewership is central in these marketing campaigns, but no large-scale studies have been conducted to predict viewership previously. This paper evaluates three different machine learning algorithms with regard to the three different error metrics MAE, MAPE and RMSE; and presents novel features for predicting viewership. Different models are chosen through recursive feature elimination using k-fold cross-validation with respect to both MAE and MAPE separately. The models are evaluated on an independent test and show promising results, on par with manual expert predictions. None of the models can be said to be significantly better than another. XGBoost optimized for MAPE obtained the lowest MAE error score of 282.54 and lowest MAPE error score of 41.36% on the test set, in comparison to expert predictions with 288.06 MAE and 83.05% MAPE. Furthermore, the study illustrates the importance of past viewership and streamer variety to predict future viewership.