Discrepancy Directed Model Acquisition for Adaptive Perceptual Systems

For complex perceptual tasks that are characterized by object occlusion and nonstationarity, recognition systems with adaptive signal processing front-ends have been developed. These systems rely on hand-crafted symbolic object models, which constitutes a knowledge acquisition bottleneck. We propose an approach to automate object model acquisition that relies on the detection and resolution of signal processing and interpretation discrepancies. The approach is applied to the task of acquiring acoustic-event models for the Sound Understanding Testbed (SUT). 1 Introduction To meet the challenge of recognition in environments that are characterized by varying signal-to-noise ratio, unpredictable object activity and possible object occlusion, Adaptive Perceptual Systems [ Draper, 1993; Lesser et al., 1993; Ming and Bhanu, 1990 ] have emerged. Recognition in such systems is dependent on the interaction between feature extraction and interpretation /matching: failure to account for some or ..

Learning Image to Symbol Conversion

A common paradigm in object recognition is to extract symbolic and/or numeric features from an image as a preprocessing step for classification. The machine learning and pattern recognition communities have produced many techniques for classifying instances given such features. In contrast, learning to extract a distinguishing set of features that will lead to unambiguous instance classification has received comparatively little attention. We propose a learning paradigm that integrates feature extraction and classifier induction, exploiting their close interrelationship to give improved classification performance. Introduction Object recognition systems can conceptually be divided into two phases: feature extraction and recognition. In the feature extraction phase, feature vectors are extracted for each instance. In general, the features are hand selected, as are their parameters, for example the cut-off frequencies of a bandpass filter or the window size of a convolution operator. In..

Downregulation of mouse intestinal Na(+)-coupled glucose transporter SGLT1 by gum arabic (Acacia Senegal)

Intestinal Na(+)-coupled glucose transporter SGLT1 determines the rate of glucose transport, which in turn influences glucose-induced insulin release and development of obesity. The present study explored effects of Gum Arabic (GA), a dietary polysaccharide from dried exudates of Acacia Senegal, on intestinal glucose transport and body weight in wild-type C57Bl/6 mice. Treatment with GA (100 g/l) in drinking water for four weeks did not affect intestinal SGLT1 transcript levels but decreased SGLT1 protein abundance in jejunal brush border membrane vesicles. Glucose-induced jejunal short-circuit currents revealed that GA treatment decreased electrogenic glucose transport. Drinking a 20% glucose solution for four weeks significantly increased body weight and fasting plasma glucose concentrations, effects significantly blunted by simultaneous treatment with GA. GA further significantly blunted the increase in body weight, fasting plasma glucose and fasting insulin concentrations during high fat diet. In conclusion, the present observations disclose a completely novel effect of gum arabic, i.e. its ability to decrease intestinal SGLT1 expression and activity and thus to counteract glucose-induced obesity

Upregulation of intestinal NHE3 following saline ingestion.

Contains fulltext : 187567.pdf (publisher's version ) (Open Access)BACKGROUND: Little is known about the effect of salt content of ingested fluid on intestinal transport processes. Osmosensitive genes include the serum- and glucocorticoid-inducible kinase SGK1, which is up-regulated by hyperosmolarity and cell shrinkage. SGK1 is in turn a powerful stimulator of the intestinal Na(+)/H(+) exchanger NHE3. The present study was thus performed to elucidate, whether the NaCl content of beverages influences NHE3 activity. METHODS: Mice were offered access to either plain water or isotonic saline ad libitum. NHE3 transcript levels and protein abundance in intestinal tissue were determined by confocal immunofluorescent microscopy, RT-PCR and western blotting, cytosolic pH (pHi) in intestinal cells from 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) fluorescence and Na(+)/H(+) exchanger activity from the Na(+) dependent realkalinization following an ammonium pulse. RESULTS: Saline drinking significantly enhanced fluid intake and increased NHE3 transcript levels, NHE3 protein and Na(+)/H(+) exchanger activity. CONCLUSIONS: Salt content of ingested fluid has a profound effect on intestinal Na(+)/H(+) exchanger expression and activity

Father Sri B Siva Rao,

my beloved husband and rest of the family For all their support and encouragement 3 TABLE OF CONTENTS ACKNOWLEDGEMENTS................................................................................ 1 SUMMARY.......................................................................................................... 2 ZUSAMMENFASSUNG....................................................................................