517 research outputs found
A case of sitosterolaemia with stomatocyticanaemia and thrombocytopenia treated with Ezetimibe with good response
A monument to the player: Preserving a landscape of socio-cultural capital in the transitional MMORPG
This is the pre-print version of the Article. The official published version can be accessed from the links below - Copyright @ 2012 Taylor & Francis LtdMassively multiplayer online role-playing games (MMORPGs) produce dynamic socio-ludic worlds that nurture both culture and gameplay to shape experiences. Despite the persistent nature of these games, however, the virtual spaces that anchor these worlds may not always be able to exist in perpetuity. Encouraging a community to migrate from one space to another is a challenge now facing some game developers. This paper examines the case of Guild Wars® and its “Hall of Monuments”, a feature that bridges the accomplishments of players from the current game to the forthcoming sequel. Two factor analyses describe the perspectives of 105 and 187 self-selected participants. The results reveal four factors affecting attitudes towards the feature, but they do not strongly correlate with existing motivational frameworks, and significant differences were found between different cultures within the game. This informs a discussion about the implications and facilitation of such transitions, investigating themes of capital, value perception and assumptive worlds. It is concluded that the way subcultures produce meaning needs to be considered when attempting to preserve the socio-cultural landscape
A mouse model of sitosterolemia: absence of Abcg8/sterolin-2 results in failure to secrete biliary cholesterol
BACKGROUND: Mutations in either of two genes comprising the STSL locus, ATP-binding cassette (ABC)-transporters ABCG5 (encoding sterolin-1) and ABCG8 (encoding sterolin-2), result in sitosterolemia, a rare autosomal recessive disorder of sterol trafficking characterized by increased plasma plant sterol levels. Based upon the genetics of sitosterolemia, ABCG5/sterolin-1 and ABCG8/sterolin-2 are hypothesized to function as obligate heterodimers. No phenotypic difference has yet been described in humans with complete defects in either ABCG5 or ABCG8. These proteins, based upon the defects in humans, are responsible for regulating dietary sterol entry and biliary sterol secretion. METHODS: In order to mimic the human disease, we created, by a targeted disruption, a mouse model of sitosterolemia resulting in Abcg8/sterolin-2 deficiency alone. Homozygous knockout mice are viable and exhibit sitosterolemia. RESULTS: Mice deficient in Abcg8 have significantly increased plasma and tissue plant sterol levels (sitosterol and campesterol) consistent with sitosterolemia. Interestingly, Abcg5/sterolin-1 was expressed in both liver and intestine in Abcg8/sterolin-2 deficient mice and continued to show an apical expression. Remarkably, Abcg8 deficient mice had an impaired ability to secrete cholesterol into bile, but still maintained the ability to secrete sitosterol. We also report an intermediate phenotype in the heterozygous Abcg8+/- mice that are not sitosterolemic, but have a decreased level of biliary sterol secretion relative to wild-type mice. CONCLUSION: These data indicate that Abcg8/sterolin-2 is necessary for biliary sterol secretion and that loss of Abcg8/sterolin-2 has a more profound effect upon biliary cholesterol secretion than sitosterol. Since biliary sitosterol secretion is preserved, although not elevated in the sitosterolemic mice, this observation suggests that mechanisms other than by Abcg8/sterolin-2 may be responsible for its secretion into bile
Endogenous fantasy and learning in digital games.
Many people believe that educational games are effective because they motivate children to actively engage in a learning activity as part of playing the game. However, seminal work by Malone (1981), exploring the motivational aspects of digital games, concluded that the educational effectiveness of a digital game depends on the way in which learning content is integrated into the fantasy context of the game. In particular, he claimed that content which is intrinsically related to the fantasy will produce better learning than that which is merely extrinsically related. However, this distinction between intrinsic and extrinsic (or endogenous and exogenous) fantasy is a concept that has developed a confused standing over the following years. This paper will address this confusion by providing a review and critique of the empirical and theoretical foundations of endogenous fantasy, and its relevance to creating educational digital games. Substantial concerns are raised about the empirical basis of this work and a theoretical critique of endogenous fantasy is offered, concluding that endogenous fantasy is a misnomer, in so far as the "integral and continuing relationship" of fantasy cannot be justified as a critical means of improving the effectiveness of educational digital games. An alternative perspective on the intrinsic integration of learning content is described, incorporating game mechanics, flow and representations
The Malthusian Paradox: performance in an alternate reality game
The Malthusian Paradox is a transmedia alternate reality game (ARG) created by artists Dominic Shaw and Adam Sporne played by 300 participants over three months. We explore the design of the game, which cast players as agents of a radical organisation attempting to uncover the truth behind a kidnapping and a sinister biotech corporation, and highlight how it redefined performative frames by blurring conventional performer and spectator roles in sometimes discomforting ways. Players participated in the game via a broad spectrum of interaction channels, including performative group spectacles and 1-to-1 engagements with game characters in public settings, making use of low- and high-tech physical and online artefacts including bespoke and third party websites. Players and game characters communicated via telephony and social media in both a designed and an ad-hoc manner. We reflect on the production and orchestration of the game, including the dynamic nature of the strong episodic narrative driven by professionally produced short films that attempted to respond to the actions of players; and the difficulty of designing for engagement across hybrid and temporally expansive performance space. We suggest that an ARG whose boundaries are necessarily unclear affords rich and emergent, but potentially unsanctioned and uncontrolled, opportunities for interactive performance, which raises significant challenges for design
“It’s like my life but more, and better!” - Playing with the Cathaby Shark Girls: MMORPGs, young people and fantasy-based social play
This article is available open access through the publisher’s website at the link below. Copyright @ 2011 A B Academic Publishers.Digital technology has opened up a range of new on-line leisure spaces for young people. Despite their popularity, on-line games and Massive Multiplayer Online Role Playing Games in particular are still a comparatively under-researched area in the fields of both Education and more broadly Youth Studies. Drawing on a Five year ethnographic study, this paper considers the ways that young people use the virtual spaces offered by MMORPGs. This paper suggests that MMORPGs represent significant arenas within which young people act out a range of social narratives through gaming. It argues that MMORPG have become important fantasy spaces which offer young people possibilities to engage in what were formally material practices. Although this form of play is grounded in the everyday it also extends material practices and offers new and unique forms of symbolic experimentation, thus I argue that game-play narratives cannot be divorced from the everyday lives of their participants
Localization of ABCG5 and ABCG8 proteins in human liver, gall bladder and intestine
BACKGROUND: The molecular mechanisms that regulate the entry of dietary sterols into the body and their removal via hepatobiliary secretion are now beginning to be defined. These processes are specifically disrupted in the rare autosomal recessive disease, Sitosterolemia (MIM 210250). Mutations in either, but not both, of two genes ABCG5 or ABCG8, comprising the STSL locus, are now known to cause this disease and their protein products are proposed to function as heterodimers. Under normal circumstances cholesterol, but not non-cholesterol sterols, is preferentially absorbed from the diet. Additionally, any small amounts of non-cholesterol sterols that are absorbed are rapidly taken up by the liver and preferentially excreted into bile. Based upon the defects in sitosterolemia, ABCG5 and ABCG8 serve specifically to exclude non-cholesterol sterol entry at the intestinal level and are involved in sterol excretion at the hepatobiliary level. METHODS: Here we report the biochemical and immuno-localization of ABCG5 and ABCG8 in human liver, gallbladder and intestine using cell fractionation and immunohistochemical analyses. RESULTS: We raised peptide antibodies against ABCG5 and ABCG8 proteins. Using human liver samples, cell fractionation studies showed both proteins are found in membrane fractions, but they did not co-localize with caveolin-rafts, ER, Golgi or mitochondrial markers. Although their distribution in the sub-fractions was similar, they were not completely contiguous. Immunohistochemical analyses showed that while both proteins were readily detectable in the liver, ABCG5 was found predominately lining canalicular membranes, whereas ABCG8 was found in association with bile duct epithelia. At the cellular level, ABCG5 appeared to be apically expressed, whereas ABCG8 had a more diffuse expression pattern. Both ABCG5 and ABCG8 appeared to localize apically as shown by co-localization with MRP2. The distribution patterns of ABCG5 and ABCG8 in the gallbladder were very similar to each other. In the small intestine both ABCG5 and ABCG8 appear to line the brush border. However, at the level of the enterocyte, the cellular distribution patterns of ABCG5 and ABCG8 differed, such that ABCG5 was more diffuse, but ABCG8 was principally apical. Using standard deglycosylation methods, ABCG5 and ABCG8 do not appear to be glycosylated, suggesting a difference between human and mouse proteins. CONCLUSION: We report the distribution patterns of ABCG5 and ABCG8 in human tissues. Cell fractionation studies showed that both proteins co-fractionated in general, but could also be found independent of each other. As predicted, they are expressed apically in both intestine and liver, although their intracellular expression patterns are not completely congruent. These studies support the concept of heterodimerization of ABCG5 and ABCG8, but also support the notion that these proteins may have an independent function
Cerebral Accumulation of Dietary Derivable Plant Sterols does not Interfere with Memory and Anxiety Related Behavior in Abcg5−/− Mice
Plant sterols such as sitosterol and campesterol are frequently applied as functional food in the prevention of atherosclerosis. Recently, it became clear that plasma derived plant sterols accumulate in murine brains. We questioned whether plant sterols in the brain are associated with alterations in brain cholesterol homeostasis and subsequently with brain functions. ATP binding cassette (Abc)g5−/− mice, a phytosterolemia model, were compared to Abcg5+/+ mice for serum and brain plant sterol accumulation and behavioral and cognitive performance. Serum and brain plant sterol concentrations were respectively 35–70-fold and 5–12-fold increased in Abcg5−/− mice (P < 0.001). Plant sterol accumulation resulted in decreased levels of desmosterol (P < 0.01) and 24(S)-hydroxycholesterol (P < 0.01) in the hippocampus, the brain region important for learning and memory functions, and increased lanosterol levels (P < 0.01) in the cortex. However, Abcg5−/− and Abcg5+/+ displayed no differences in memory functions or in anxiety and mood related behavior. The swimming speed of the Abcg5−/− mice was slightly higher compared to Abcg5+/+ mice (P < 0.001). In conclusion, plant sterols in the brains of Abcg5−/− mice did have consequences for brain cholesterol metabolism, but did not lead to an overt phenotype of memory or anxiety related behavior. Thus, our data provide no contra-indication for nutritional intake of plant sterol enriched nutrition
Generalised Player Modelling : Why Artificial Intelligence in Games Should Incorporate Meaning, with a Formalism for so Doing
General game-playing artificial intelligence (AI) has recently seen important advances due to the various techniques known as ‘deep learning’. However, in terms of human-computer interaction, the advances conceal a major limitation: these algorithms do not incorporate any sense of what human players find meaningful in games. I argue that adaptive game AI will be enhanced by a generalised player model, because games are inherently human artefacts which require some encoding of the human perspective in order to respond naturally to individual players. The player model provides constraints on the adaptive AI, which allow it to encode aspects of what human players find meaningful. I propose that a general player model requires parameters for the subjective experience of play, including: player psychology, game structure, and actions of play. I argue that such a player model would enhance efficiency of per-game solutions, and also support study of game-playing by allowing (within-player) comparison between games, or (within-game) comparison between players (human and AI). Here we detail requirements for functional adaptive AI, arguing from first-principles drawn from games research literature, and propose a formal specification for a generalised player model based on our ‘Behavlets’ method for psychologically-derived player modelling.Peer reviewe
Introduction: The Other Caillois: The Many Masks of Game Studies
The legacy of the rich, stratified work of Roger Caillois, the multifaceted and complex French scholar and intellectual, seems to have almost solely impinged on game studies through his most popular work, Les Jeux et les Hommes. Translated in English as Man, Play and Games, this is the text which popularized Caillois’ ideas among those who do study and research on games and game cultures today, and which most often appears in publications that attempt to historicize and introduce to the study of games—perhaps on a par with Johan Huizinga’s Homo Ludens. The purpose of this article is to introduce the papers and general purposes of a collected edition that aims to shift the attention of game scholars toward a more nuanced and comprehensive view of Roger Caillois, beyond the textbook interpretations usually received in game studies over the last decade or so
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