298 research outputs found
An Infrastructure for acquiring high quality semantic metadata
Because metadata that underlies semantic web applications is gathered from distributed and heterogeneous data sources, it is important to ensure its quality (i.e., reduce duplicates, spelling errors, ambiguities). However, current infrastructures that acquire and integrate semantic data have only marginally addressed the issue of metadata quality. In this paper we present our metadata acquisition infrastructure, ASDI, which pays special attention to ensuring that high quality metadata is derived. Central to the architecture of ASDI is a erification engine that relies on several semantic web tools to check the quality of the derived data. We tested our prototype in the context of building a semantic web portal for our lab, KMi. An experimental evaluation omparing the automatically extracted data against manual annotations indicates that the verification engine enhances the quality of the extracted semantic metadata
Expertise-based peer selection in Peer-to-Peer networks
Peer-to-Peer systems have proven to be an effective way of sharing data. Modern protocols are able to efficiently route a message to a given peer. However, determining the destination peer in the first place is not always trivial. We propose a a message to a given peer. However, determining the destination peer in the first place is not always trivial. We propose a model in which peers advertise their expertise in the Peer-to-Peer network. The knowledge about the expertise of other peers forms a semantic topology. Based on the semantic similarity between the subject of a query and the expertise of other peers, a peer can select appropriate peers to forward queries to, instead of broadcasting the query or sending it to a random set of peers. To calculate our semantic similarity measure, we make the simplifying assumption that the peers share the same ontology. We evaluate the model in a bibliographic scenario, where peers share bibliographic descriptions of publications among each other. In simulation experiments complemented with a real-world field experiment, we show how expertise-based peer selection improves the performance of a Peer-to-Peer system with respect to precision, recall and the number of messages
A wide-spectrum approach to modelling and analysis of organisation for machine-assisted decision-making
This paper describes a modeling approach that helps to represent necessary aspects of complex socio-technical systems, such as organization, in an integrated form and provides a simulation technique for analyzing these organisations. An actor-based language is introduced and compared to a conventional simulation approach (Stock-and-Flow) by simulating aspects of a software services company
Exploring Large Document Repositories with RDF Technology: The DOPE Project
This thesaurus-based search system uses automatic indexing, RDF-based querying, and concept-based visualization of results to support exploration of large online document repositories
Role of Receptor-Interacting Protein 140 in human fat cells
<p>Abstract</p> <p>Background</p> <p>Mice lacking <it>Receptor-interacting protein 140 (RIP140) </it>have reduced body fat which at least partly is mediated through increased lipid and glucose metabolism in adipose tissue. In humans, <it>RIP140 </it>is lower expressed in visceral white adipose tissue (WAT) of obese versus lean subjects. We investigated the role of <it>RIP140 </it>in human subcutaneous WAT, which is the major fat depot of the body.</p> <p>Methods</p> <p>Messenger RNA levels of <it>RIP140 </it>were measured in samples of subcutaneous WAT from women with a wide variation in BMI and in different human WAT preparations. <it>RIP140 </it>mRNA was knocked down with siRNA in <it>in vitro </it>differentiated adipocytes and the impact on glucose transport and mRNA levels of target genes determined.</p> <p>Results</p> <p><it>RIP140 </it>mRNA levels in subcutaneous WAT were decreased among obese compared to lean women and increased by weight-loss, but did not associate with mitochondrial DNA copy number. <it>RIP140 </it>expression increased during adipocyte differentiation <it>in vitro </it>and was higher in isolated adipocytes compared to corresponding pieces of WAT. Knock down of <it>RIP140 </it>increased basal glucose transport and mRNA levels of <it>glucose transporter 4 </it>and <it>uncoupling protein-1</it>.</p> <p>Conclusions</p> <p>Human <it>RIP140 </it>inhibits glucose uptake and the expression of genes promoting energy expenditure in the same fashion as the murine orthologue. Increased levels of human <it>RIP140 </it>in subcutaneous WAT of lean subjects may contribute to economize on energy stores. By contrast, the function and expression pattern does not support that <it>RIP140 </it>regulate human obesity.</p
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Combined transcriptomic-(1)H NMR metabonomic study reveals yhat monoethylhexyl phthalate stimulates adipogenesis and glyceroneogenesis in human adipocytes
Adipose tissue is a major storage site for lipophilic environmental contaminants. The environmental metabolic disruptor hypothesis postulates that some pollutants can promote obesity or metabolic disorders by activating nuclear receptors involved in the control of energetic homeostasis. In this context, monoethylhexyl phthalate (MEHP) is of particular concern since it was shown to activate the peroxisome proliferator-activated receptor Ī³ (PPARĪ³) in 3T3-L1 murine preadipocytes. In the present work, we used an untargeted, combined transcriptomic-(1)H NMR-based metabonomic approach to describe the overall effect of MEHP on primary cultures of human subcutaneous adipocytes differentiated in vitro. MEHP stimulated rapidly and selectively the expression of genes involved in glyceroneogenesis, enhanced the expression of the cytosolic phosphoenolpyruvate carboxykinase, and reduced fatty acid release. These results demonstrate that MEHP increased glyceroneogenesis and fatty acid reesterification in human adipocytes. A longer treatment with MEHP induced the expression of genes involved in triglycerides uptake, synthesis, and storage; decreased intracellular lactate, glutamine, and other amino acids; increased aspartate and NAD, and resulted in a global increase in triglycerides. Altogether, these results indicate that MEHP promoted the differentiation of human preadipocytes to adipocytes. These mechanisms might contribute to the suspected obesogenic effect of MEHP
Social Change and Betty Friedan's The Feminine Mystique: A Study of the Charismatic Author-Leader
In this thesis I explore the significance of the publication of Betty Friedan's The Feminine Mystique (1963) to the emergence of the second wave Women's Liberation Movement in the US in the late 1960s. To this end, I deploy key concepts provided through social movement theory (eg collective identity, collective action frames, social problem construction). I also incorporate Max Weber and Antonio Gramsci's insights on the indispensable role played by leaders who demonstrate a clear and effective political will. Weber's three part model of pure charisma is used as a general template for understanding the impact of Friedan's text. I critique aspects of Weber's theory of charisma, in particular his failure to appreciate that the written word can mark the initial emergence phase of charisma rather than its routinisation. I augment Weber's insights on charismatic leadership by attending to Gramsci's emphasis on the necessity of winning the 'war of ideas' that must be waged at the level of civil society within advanced capitalist societies. I examine Gramsci's understanding of the power available to the organic intellectual who is aligned with the interests of subaltern groups and who succeeds in revealing the hegemonic commitments of accepted 'common sense'. In the latter part of this thesis, I apply these many useful concepts to my case study analysis of Betty Friedan's The Feminine Mystique. I argue that Friedan's accessible, middlebrow text gave birth to a new discursive politics which was critically important not only for older women, but for a younger generation of more radicalised women. I emphasise how Friedan's text mounted a concerted attack on the discursive construction of femininity under patriarchal capitalism. I question Friedan's diagnostic claim that the problems American women faced were adequately captured by the terminology of the trapped housewife syndrome. I conclude by arguing that social movement researchers have to date failed to appreciate the leadership potential of the charismatic author-leader who succeeds in addressing and offering a solution to a pressing social problem through the medium of a best-selling, middlebrow text
Resilient functioning is associated with altered structural brain network topology in adolescents exposed to childhood adversity
Childhood adversity is one of the strongest predictors of adolescent mental illness. Therefore, it is critical that the mechanisms that aid resilient functioning in individuals exposed to childhood adversity are better understood. Here, we examined whether resilient functioning was related to structural brain network topology. We quantified resilient functioning at the individual level as psychosocial functioning adjusted for the severity of childhood adversity in a large sample of adolescents (N = 2406, aged 14ā24). Next, we examined nodal degree (the number of connections that brain regions have in a network) using brain-wide cortical thickness measures in a representative subset (N = 275) using a sliding window approach. We found that higher resilient functioning was associated with lower nodal degree of multiple regions including the dorsolateral prefrontal cortex, the medial prefrontal cortex, and the posterior superior temporal sulcus (z > 1.645). During adolescence, decreases in nodal degree are thought to reflect a normative developmental process that is part of the extensive remodeling of structural brain network topology. Prior findings in this sample showed that decreased nodal degree was associated with age, as such our findings of negative associations between nodal degree and resilient functioning may therefore potentially resemble a more mature structural network configuration in individuals with higher resilient functioning
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