Segmentation of temporal mesh sequences into rigidly moving components

In this paper is considered the segmentation of meshes into rigid components given temporal sequences of deforming meshes. We propose a fully automatic approach that identifies model parts that consistently move rigidly over time. This approach can handle meshes independently reconstructed at each time instant. It allows therefore for sequences of meshes with varying connectivities as well as varying topology. It incrementally adapts, merges and splits segments along a sequence based on the coherence of motion information within each segment. In order to provide tools for the evaluation of the approach, we also introduce new criteria to quantify a mesh segmentation. Results on both synthetic and real data as well as comparisons are provided in the paper.     

Cloning and sequence analysis of cDNAs encoding precursors of sarafotoxins. Evidence for an unusual "rosary-type" organization

Sarafotoxins (SRTXs) are 21-amino acid peptides structurally and functionally similar to endothelins (ETs). To understand how SRTXs are overproduced in venom glands of the snakes Atractaspis engaddensis and hence used as toxins, we cloned cDNAs encoding SRTXs and elucidated their nucleotide sequences. We predict that SRTX precursors are large prepropolypeptide chains with an unusual "rosary-type" structure made of 12 successive similar stretches of 40 residues (39 in the first stretch). Each stretch begins with a "spacer" of 19 invariant residues (18 in the first stretch) immediately followed by the sequence of one SRTX isoform. Six different isoforms are identified within a single precursor molecule. Maturation of the precursor may require endopeptidases that cleave the Leu-Cys bond and the Trp-Arg/Lys bond invariably found at the SRTX N and C termini, respectively.     

Audio-visual speech modeling for continuous speech recognition

This paper describes a speech recognition system that uses both acoustic and visual speech information to improve recognition performance in noisy environments. The system consists of three components: a visual module; an acoustic module; and a sensor fusion module. The visual module locates and tracks the lip movements of a given speaker and extracts relevant speech features. This task is performed with an appearance-based lip model that is learned from example images. Visual speech features are represented by contour information of the lips and grey-level information of the mouth area. The acoustic module extracts noise-robust features from the audio signal. Finally the sensor fusion module is responsible for the joint temporal modeling of the acoustic and visual feature streams and is realized using multistream hidden Markov models (HMMs). The multistream method allows the definition of different temporal topologies and levels of stream integration and hence enables the modeling of temporal dependencies more accurately than traditional approaches. We present two different methods to learn the asynchrony between the two modalities and how to incorporate them in the multistream models. The superior performance for the proposed system is demonstrated on a large multispeaker database of continuously spoken digits. On a recognition task at 15 dB acoustic signal-to-noise ratio (SNR), acoustic perceptual linear prediction (PLP) features lead to 56% error rate, noise robust RASTA-PLP (relative spectra) acoustic features to 7.2% error rate and combined noise robust acoustic features and visual features to 2.5% error rate     

Demonstration of a tunable two-frequency projected fringe pattern with acousto-optic deflectors

We report on a fringe projector for three-dimensional shape measurement. The developed instrument is able to project a two-frequency fringe pattern, each frequency is independently controlled by electronics. Moreover, each phase of the two fringe patterns is also independently adjusted. The projection system is based on the use of a pair of custom large bandwidth (40 MHz) and high efficiency (60%) TeO2 deflectors. The developed instrument offers the combined advantages of a static two-frequency fringe projector and of a tunable single frequency fringe projector.     

Two dimensional gel electrophoresis of apolipoprotein C‐III and MALDI‐TOF MS are complementary techniques for the study of combined defects in N‐ and mucin type O‐glycan biosynthesis

In the field of diseases related to glycosylation disorders, congenital defects associated with abnormalities in both O‐ and N‐glycosylation of proteins constitute arising novel entities. Defects in subunits of the conserved oligomeric Golgi protein complex have been shown to be involved in an important part of previously unsolved CDG type II combining abnormalities in both mucin type core1 O‐ and N‐glycans; furthermore, recent studies revealed that autosomal recessive cutis laxa type II could also be associated with such combined glycosylation defects. Based on the studies of serum samples from three patients including a case of cutis laxa, we present here evidence that 2‐DE of apolipoprotein C‐III in combination with MALDI‐TOF‐MS analysis of serum O‐ and N‐glycans allow the detection and the biochemical characterization of these newly recognized glycosylation disorders.     

Learning from technical documents: the role of intermodal referring expressions

OBJECTIVE: We investigated the impact of two types of intermodal referring expressions on efficiency of instructions for use. BACKGROUND: User manuals for software or technical devices such as a video recording system frequently combine verbal instructions and illustrations. Much research has shown that the presence of an illustration has a beneficial effect on learning. The present study focuses on a factor that modulates this beneficial effect. The combination of text and an illustration can be effective only if the user integrates the information coming from these two media. This integration depends largely on the intermodal referential expressions, the function of which is to mark explicitly the relations between the text and the illustration. METHOD: In an experiment (N = 104), we compared the effectiveness of two intermodal referring expressions often used in procedural texts: indexes (numbers introduced in the illustrations and in the instructions to establish cross-references) and icons (visual representations of the components of the device, which are inserted in the verbal instructions). RESULTS: The icons condition led to the most efficient use of the device. CONCLUSION: This experiment shows that learning from multimedia documents depends on the possibility of effectively connecting the verbal instructions to the illustration. APPLICATION: Taking into account the ergonomic properties of the cross-media referring expressions should allow text designers to improve the effectiveness of technical documents.     

An end-to-end prototyping framework for compliant wireless LAN transceivers with smart antennas

OFDM Wireless LANs based on the IEEE802.11 standard are complex systems in themselves. When smart antennas are used in such systems, both the MAC and the PHY layers must be redefined in order to achieve application-specific goals. As a result, the development of such systems can become impressively heavy. A complete development framework is presented here. It makes use of hardware/software co-design in order to implement all required layers to develop a wireless access point. The entire framework is targeted at an FPGA platform, providing full flexibility and processing power for the development of PHY layers.     

Sulphur poisoning and regeneration of precious metal catalysed methane combustion

In many of the applications of catalytic combustion small amounts of sulphur compounds are present in the feed gas. In the case of natural gas combustion, and solid fuel syngas, the sulphur compounds are in reduced forms. The present work investigates the influence of small quantities of reduced sulphur compounds on the combustion of methane over alumina-supported precious metal catalysts. The kinetics of the methane combustion in the presence of low concentrations of a mixture of sulphur compounds (ethyl mercaptan, methyl mercaptan, carbonyl sulphide and hydrogen sulphide) are compared with those in the absence of sulphur compounds. The ease of regeneration of the poisoned catalysts, via low temperature reduction with hydrogen, is also examined. In the conditions studied all catalysts have reduced activity in the presence of the sulphur-based gas mixture, but Pt/Al₂O₃ and Rh/Al₂O₃ are more strongly poisoned than Pd/Al₂O₃. Qualitative studies using gas chromatography with atomic emission detection of the exhaust gases, and FTIR spectroscopy of the spent Rh/Al₂O₃ catalyst, suggest that the catalysts experience a mixture of reduced and oxidised species under reaction conditions, and that sulphating of the support occurs. The regeneration step facilitates metal mobility and meets with varying success depending upon the metal. Pt/Al₂O₃ in particular is difficult to regenerate by reduction in hydrogen (400 °C for 0.5 h), and agglomeration is observed by TEM. Rh/Al₂O₃ regenerates well, and low metal particle size is maintained. A non-linear deactivation model is tested to separate sulphur-induced deactivation from ‘natural’ deactivation in the reaction mixture and preliminary results are presented.     

Dietary lipid,fatty acid oxidation and incorporation of carbon into cholesterol

Female rats (200 g) were fed a nutritionally adequate diet containing 1% by weight of corn oil (low-fat, LF), 21% of corn oil (CO) or 20% of beef tallow plus 1% of corn oil (BT) for two weeks. Food was removed for 8–12 hr, then each rat was refed for 1 hr. Each rat was injected ip with Na-³H-acetate and U-¹⁴C-Na-palmitate, (P),-oleate (O) or-linoleate (L). Expired CO₂ was collected for 2 hr. Liver, heart and serum were obtained for analysis of total lipid¹⁴C and³H and cholesterol¹⁴C and³H. Oxidation of L was twice as great as O or P when the LF diet was fed. CO and BT diets doubled oxidation of O to equal L, and increased oxidation of P, 50%. In liver and serum P was retained to a greater extent than O or L on BT and CO diets. Incorporation of acetate into total lipid was highest on LF diet and reduced by feeding either CO or BT. Incorporation of acetate into cholesterol was greater when BT or CO was fed than for LF.¹⁴C was incorporated into cholesterol in such small amounts that it was barely detectable and could not be counted accurately. Conclusions are that (a) dietary fat affects rate of oxidation of uniformly labeled palmitate and oleate, but not linoleate, (b) acetate is a more ready precursor to cholesterol than is fatty acid carbon, and (c) the acetate incorporated into cholesterol when polyunsaturated fat is fed is not derived directly from fatty acid carbon. The failure of incorporation of fatty acid carbon into cholesterol within 2 hr of administration opens the question of compartmentation of acetate as to its metabolic source. Colorado Agricultural Experiment Station Scientific Series Paper No. 1510.     

Asparagine-127 of xylanase A from Streptomyces lividans, a key residue in glycosyl hydrolases of superfamily 4/7: kinetic evidence for its involvement in stabilization of the catalytic intermediate

Site-directed mutagenesis of asparagine-127 (N127) of xylanase A (XlnA) from Streptomyces lividans, belonging to family 10 and superfamily 4/7 of glycosyl hydrolases, was chosen to study the role of this conserved residue. The isosteric mutation N127D introduced did not affect the fold of XlnA as revealed by circular dichroism. Comparison of the kinetic constants of N127D and wild-type XlnA revealed a 70-fold decrease in the specificity constant (kcat/K(M)) towards birchwood xylan, which is attributed solely to the difference in the kcat value and indicates a role of N127 in stabilization of the catalytic intermediate. N127 also plays a role in maintaining the ionization states of the two catalytic residues, as shown by the modified pH profile of XlnA-N127D. Characterization of XlnA-N127D and the analysis of the three-dimensional structure of XlnA converge towards a stabilization role for N127 in the catalytic site of XlnA.