Carl Owen

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Mobile robot navigation under controlled laboratory conditions is, by now, state of the art and reliably achievable. To transfer navigation mechanisms used in such small-scale environments to applications in untreated, large environments, however, is not trivial, and typically requires modifications to the original navigation mechanism: scaling up is hard.(More)
Protein tyrosine phosphatase 1B (PTP1B), a key negative regulator of leptin and insulin signaling, is positively correlated with adiposity and contributes to insulin resistance. Global PTP1B deletion improves diet-induced obesity and glucose homeostasis via enhanced leptin signaling in the brain and increased insulin signaling in liver and muscle. However,(More)
Background: Components of the insulin receptor signaling pathway are probably some of the best studied ones. Even though methods for studying these components are well established, the in vivo effects of different fasting regimens, and the time-course of insulin receptor phosphorylation and that of its downstream components in insulin-sensitive peripheral(More)
Obesity is associated with induction of the ER (endoplasmic reticulum)-stress response signalling and insulin resistance. PTP1B (protein tyrosine phosphatase 1B) is a major regulator of adiposity and insulin sensitivity. The aim of the present study was to investigate the role of L-PTP1B (liver-specific PTP1B) in chronically HFD (high-fat diet) and(More)
The synthetic retinoid, Fenretinide (FEN), inhibits obesity and insulin resistance in mice and is in early clinical trials for treatment of insulin resistance in obese humans. We aimed to determine whether alterations in retinoic acid (RA)-responsive genes contribute to the beneficial effects of FEN. We examined the effect of FEN on 3T3-L1 adipocyte(More)
In this paper we present results of experiments carried out with a route learning system for a mobile robot, conducted in a `real world' environment covering distances of several hundred metres. The system uses no odometry and is based on a self-organising mapbuilding process using perceptual landmarks. A performance metric is deened and used to measure the(More)
The gastrointestinal mucus layer is colonized by a dense community of microbes catabolizing dietary and host carbohydrates during their expansion in the gut. Alterations in mucosal carbohydrate availability impact on the composition of microbial species. Ruminococcus gnavus is a commensal anaerobe present in the gastrointestinal tract of >90% of humans and(More)
Sialidases are a large group of enzymes, the majority of which catalyses the cleavage of terminal sialic acids from complex carbohydrates on glycoproteins or glycolipids. In the gastrointestinal (GI) tract, sialic acid residues are mostly found in terminal location of mucins via α2-3/6 glycosidic linkages. Many enteric commensal and pathogenic bacteria can(More)