36 research outputs found
Hierarchical singleton-type recurrent neural fuzzy networks for noisy speech recognition
This paper proposes noisy speech recognition using hierarchical singleton-type recurrent neural fuzzy networks (HSRNFNs). The proposed HSRNFN is a hierarchical connection of two singleton-type recurrent neural fuzzy networks (SRNFNs), where one is used for noise filtering and the other for recognition. The SRNFN is constructed by recurrent fuzzy if-then rules with fuzzy singletons in the consequences, and their recurrent properties make them suitable for processing speech patterns with temporal characteristics. Inn, words recognition, 77, SRNFNs are created for modeling n words, where each SRNFN receives the current frame feature and predicts the next one of its modeling word. The prediction error of each SRNFN is used as recognition criterion. In filtering, one SRNFN is created, and each SRNFN recognizer is connected to the same SRNFN filter, which filters noisy speech patterns in the feature domain before feeding them to the SRNFN recognizer. Experiments with Mandarin word recognition under different types of noise are performed. Other recognizers, including multilayer perceptron (MLP), time-delay neural networks (TDNNs), and hidden Markov models (HMMs), are also tested and compared. These experiments and comparisons demonstrate good results with HSRNFN for noisy speech recognition tasks
Effects of diets supplemented with recombinant epidermal growth factor and glutamine on gastrointestinal tract development of early-weaned piglets
This study attempted to determine effects of recombinant porcine epidermal growth factor (pEGF) and glutamine (Gln) supplement on the growth performance and intestinal development of piglets weaned at 14 days of age. A total of ninety-six piglets were allotted to one of four dietary treatments which comprised inclusion of 1.0 mg pEGF supernatant/kg diet or 0.5% Gln both alone and in combination. Each treatment consisted of four replicates with six pigs per pen for a 28 days experimental period. Two pigs per replicate were sacrificed and gastrointestinal tract samples were collected on day 14. Data showed that dietary treatment failed to promote growth performance. On day 14, diets supplemented with pEGF elevated pancreatic chymotrypsin, jejunal alkaline phosphatase, sucrase, lactase and maltase activities (p<0.05), but failed to alter the small intestinal villus morphology, DNA, or protein content of gastrointestinal mucosa. Diets supplemented with Gln increased pancreatic chymotrypsin activity, tended to enhance the protein contents of gastric (p = 0.08) and jejunal mucosa (p = 0.09) but did not influence the serum IgA level or the enzyme activity in the gastrointestinal tract. On day 28, the diets supplemented with Gln increasedt (p<0.05) serum IgA and the proliferation of peripheral blood mononuclear cells by PHA stimulation. However, a combination of pEGF and Gln did not have a synergistic effect on these biomarkers in early-weaned piglets. The results demonstrate that diets supplemented with recombinant pEGF supernatant indeed improve intestinal digestive enzyme activity and diets supplemented with Gln increases the immune response in early-weaned piglets
H-1 NMR characterization of a combination model of the mixed micelle taurocholate and 1,2-ethylene-di-N-n-butylcarbamate
The structures of micelles of taurocholate (TC) have been debated for many years. According to Funasaki's model based on 2D NMR studies, anti-parallel and parallel back-to-back dimers have been proposed as two major fragments in the micellar TC. However, according to Galantini's model based on X-ray crystal structure, anti-parallel and parallel face-to-face dimers have been proposed as two major fragments in the micelle. We propose a combined model from these two models for the structures of micelles of TC and suggest that these structures are equally composed of these four dimeric fragments. Lipid molecules can only insert into back-to-back dimeric fragments but not into face-to-face dimeric fragments in the mixed micelles of TC and lipid. A short-chain analog of glycerol lipid, 1,2-ethylene-di-N-n-butylcarbamate (1), was synthesized and was mixed with the micellar TC to form the mixed micelle of TC and compound 1. From the H-1 NMR spectra, the (omega-methyl and beta-methylene protons of compound 1 split after formation of the mixed micelle with TC. Therefore, half of the compound 1 molecules insert into the anti-parallel back-to-back dimers in the mixed micelle, and the other half of the compound 1 molecules insert into the parallel back-to-back dimers in the mixed micelle
Stereoselective inhibition of butyrylcholinesterase by enantiomers of exo- and endo-2-norbornyl-N-n-butylcarbamates
Enantiomers of exo- and endo-2-norbornyl-N-n-butylcarbamates were characterized as pseudo substrate inhibitors of butyrylcholinesterase. These inhibitions discriminate enantiomers of the inhibitors and therefore show stereoselectivity for the enzyme. For inhibitions by (R)-(+)- and (S)-(-)-exo-2-norbornyl-N-n-butylcarbamates, R-enantiomer is a more potent inhibitor than S-enantiomer. But, for inhibitions by (R)-(+)- and (S)-(-)-endo-2-norbornyl-N-n-butylcarbamates, S-enantiomer is a more potent inhibitor than R-enantiomer. Optically pure (R)-(+)-exo-, (S)-(-)-exo-, (R)-(+)-endo-, and (S)-(-)-endo-2-norbornyl-N-n-butylcarbamates were synthesized from condensations of optically pure (R)-(+)-exo-, (S)-(-)-exo-, (R)-(+)-endo-, and (S)-(-)-endo-2-norborneols with n-butyl isocyanate, respectively. Optically pure norborneols were obtained from kinetic resolution of their racemic esters by lipase catalysis in organic solvent
Comparison of Active Sites of Butyrylcholinesterase and Acetylcholinesterase Based on Inhibition by Geometric Isomers of Benzene-di-N-Substituted Carbamates
We have reported that benzene-1,2-,1,3-, and 1,4-di-N-substituted carbamates (1-15) are characterized as the conformationally constrained inhibitors of acetylcholinesterase and mimic gauche, eclipsed, and anti-conformations of acetylcholine, respectively (J Biochein Mol Toxicol 2007;21:348-353). We further report the inhibition of butyrylcholinesterase by these inhibitors. Carbamates 1-15 are also characterized as the pseudosubstrate inhibitors of butyrylcholinesterase as in the acetylcholinesterase catalysis. Benzene-1,4-di-N-n-hexylcarbamate (12) and benzene1,4-di-N-n-octylcarbamate (13) are the two most potent inhibitors of butyrylcholinesterase among inhibitors 1-15. These two para compounds, with the angle of 180 degrees between two C(benzene)-O bonds, mimic the preferable anti C-O/C-N conformers for the choline ethylene backbone of butyrylcholine during the butyrylcholinesterase catalysis. The second n-hexylcarbamyl or n-octylcarbamyl moiety of inhibitors 12 and 13 is proposed to bind tightly to the peripheral anionic site of butyrylcholinesterase from molecular modeling. Butyrylcholinesterase prefers para-carbamates to ortho- and meta-carbamates, whereas acetylcholinesterase prefers para- and meta-carbamates to ortho-carbamates. This result implies that the anionic site of butyrylcholinesterase is relatively smaller than that of acetylcholinesterase because meta-carbamates, which may bind to the anionic sites of both enzymes, are not potent inhibitors of butyrylcholinesterase. (C) 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:303-308, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10:1002/jbt.2028