251 research outputs found

    Human amniotic fluid glycoproteins expressing sialyl Lewis carbohydrate antigens stimulate progesterone production in human trophoblasts in vitro

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    Background: Progesterone is thought to mediate immune modulator effects by regulating uterine responsiveness. The aim of the study was to clarify the effect of transferrin and glycodelin A (former name PP14) as sialyl Lewis X-expressing glycoproteins on the release of progesterone by trophoblast cells in vitro. Methods: Cytotrophoblast cells were prepared from human term placentas by standard dispersion of villous tissue followed by a Percoll gradient centrifugation step. Trophoblasts were incubated with varying concentrations (50-300 mug/ml) of human amniotic fluid- and serum-transferrin as well as with glycodelin A. Culture supernatants were assayed for progesterone, human chorionic gonadotropin (hCG) and cortisol by enzyme immunometric methods. Results: The release of progesterone is increased in amniotic fluid transferrin- and glycodelin A-treated trophoblast cell cultures compared to untreated trophoblast cells. There is no relation between transferrin and the hCG or cortisol production of trophoblast cells. Conclusion: The results suggest that sialyl Lewis carbohydrate antigen-expressing amniotic fluid glycoproteins modulate the endocrine function of trophoblasts in culture by upregulating progesterone production. Copyright (C) 2004 S. Karger AG, Basel

    Major memory for microblogs

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    Online social networking is vastly popular and permits its members to post their thoughts as microblogs, an opportunity that people exploit, on Facebook alone, over 30 million times an hour. Such trivial ephemera, one might think, should vanish quickly from memory; conversely, they may comprise the sort of information that our memories are tuned to recognize, if that which we readily generate, we also readily store. In the first two experiments, participants' memory for Facebook posts was found to be strikingly stronger than their memory for human faces or sentences from books-a magnitude comparable to the difference in memory strength between amnesics and healthy controls. The second experiment suggested that this difference is not due to Facebook posts spontaneously generating social elaboration, because memory for posts is enhanced as much by adding social elaboration as is memory for book sentences. Our final experiment, using headlines, sentences, and reader comments from articles, suggested that the remarkable memory for microblogs is also not due to their completeness or simply their topic, but may be a more general phenomenon of their being the largely spontaneous and natural emanations of the human mind.</p

    Purinergic signalling and immune cells

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    This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

    From Prototyping to Allotyping. The invention of change of use and the crisis of building types

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    The chapter analyses the invention and the form of the discourse on building conversion as one particular instance of redefining what a technology is and how it operates. I describe a shift from expert defined closure to lay based openness and tinkering as a shift from prototyping to allotyping: Since the early 1970s, change of use and building conversion have become a central and fashionable discourse among architects and architectural theorists. Before the 1970s, buildings were understood as technologies, as ‘society made durable’. The notion of building type was central to link a building to a given use. A bank was a bank because architects applied existing templates, prototypes, to turn a building into a bank. In the 1970s, suddenly buildings became flexible – discursively, since building conversion always existed: ‘Building type’ no longer was a meaningful link between a building and its use. A bank should not stay a bank, but become a hotel, a theatre or a flat, in short: an allotype. The chapter elucidate this central shift in thinking about buildings and reflects on the special case of allotyping buildings and how it continues to vex thinking about buildings

    Is it in the Game? Reconsidering play spaces, game definitions, theming and sports videogames

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    From the very first days of digital gaming, sport-themed videogames have been a constant and ever-popular presence. However, compared with many other genres of games, sports-themed videogames have remained relatively under-research. Using the case of ‘sports videogames’ this paper advocates a critical and located approach to understanding videogames and gameplay. Unlike many existing theorisations of gameplay, such as the ‘magic circle’ (Huizinga 1949 [1938]), which theorise play as a break from ordinary life, this paper argues for a consideration of play as a continuation of ‘the control of the established order’ (Lefebvre (1991 [1974]: 383). It argues that many videogames, and in particular sports videogames, can be understood as ‘themed’ spaces; which share similarities to other themed locations, such as fast-food restaurants and theme parks. These are ‘non-places’ (Augé 1995) themed to provide a sense of individuality, control and escape in a society that increasingly offers none

    Sleep’s Role in Schema Learning and Creative Insights

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    Purpose of Review A recent resurgence of interest in schema theory has influenced research on sleep-dependent memory consolidation and led to a new understanding of how schemata might be activated during sleep and play a role in the reorganisation of memories. This review aims to synthesise recent findings into a coherent narrative and draw overall conclusions. Recent Findings Rapid consolidation of schematic memories has been shown to benefit from an interval containing sleep. These memories have shown reduced reliance on the hippocampus following consolidation in both humans and rodents. Using a variety of methodologies, notably including the DRM paradigm, it has been shown that activation of a schema can increase the rate of false memory as a result of activation of semantic associates during slow wave sleep (SWS). Memories making use of a schema have shown increased activity in the medial prefrontal cortex, which may reflect both the schematic activation itself and a cognitive control component selecting an appropriate schema to use. SWS seems to be involved in assimilation of new memories within existing semantic frameworks and in making memories more explicit, while REM sleep may be more associated with creating entirely novel associations while keeping memories implicit. Summary Sleep plays an important role in schematic memory consolidation, with more rapid consolidation, reduced hippocampal involvement and increased prefrontal involvement as the key characteristics. Both SWS and REM sleep may have a role to play

    Between Hope and Hype: Traditional Knowledge(s) Held by Marginal Communities

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