An elastic net-based hybrid hypothesis method for compressed video sensing

Multimedia Tools and Applications - Compressed Sensing, an emerging framework for signal processing, can be used in image and video application, especially when available resources at the...     

A study of optimal viewing distance in a parallax barrier 3D display

The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D display. It can be designed based on simple geometric method and by considering the pitches of image display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction index of the cover glass, the angular behavior of the system becomes more realistic; however, the geometric method is difficult to be used. We propose a revised method for estimating the view distance and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view and shown that multiple DEPs make a circular curve around the center of the display. We prove the new concept by comparing the optical ray tracing calculations and optical measurement.     

Using simulation and multi-criteria methods to provide robust solutions to dispatching problems in a flow shop with multiple processors

Dispatching rules are important to the performance of a manufacturing system. Selective applications of different priority rules at different processing stages in a multiple workstation manufacturing system have a positive impact on shop performance. This type of problem is a combinatorial dispatching decision. However, no dispatching rule can consistently produce better performance than all other rules under a variety of operating conditions and criteria. It is the purpose of this study to provide a robust solution for a dispatching decision that will have ‘good’ performance under different operating scenarios. In this paper a simulation case of a flow shop with multiple processors is proposed, specifically a multi-layer ceramic capacitor manufacturing system. Two multiple criteria decision-making methods – techniques for order preference by similarity to ideal solution (TOPSIS) and an analytic hierarchy process (AHP) – in combination with Taguchi orthogonal array are used to find the most suitable dispatching rule for every workstation. The results show that for 15 production scenarios and 4 criteria this combinatorial dispatching rule is robust, in the sense that it outperforms other commonly employed strategies.     

Robust Fuzzy Output Sliding Control without the Requirement of State Measurement

A robust fuzzy output sliding control for nonlinear robotic arms is proposed in this paper. The proposed method not only retains the advantages of the conventional sliding mode control such as robustness against parameter variations and external disturbances, but also uses measurable output signals to define the sliding surface function. A fuzzy controller is developed to modify the control law to avoid state measurement. Control system stability is proved by using the Lyapunov stability theorem. The system robustness is guaranteed. Simulations results demonstrate the validity and effectiveness of the proposed method for uncertain nonlinear robotic arms.     

Extraction of genomic DNA and detection of single nucleotide polymorphism genotyping utilizing an integrated magnetic bead-based microfluidic platform

This study presents a new magnetic bead-based microfluidic platform, which integrates three major modules for rapid leukocytes purification, genomic DNA (gDNA) extraction and fast analysis of genetic gene. By utilizing microfluidic technologies and magnetic beads conjugated with CD_15/45 antibodies, leukocytes in a human whole blood sample can be first purified and concentrated, followed by extraction of gDNA utilizing surface-charge switchable, DNA-specific, magnetic beads in the lysis solution. Then, specific genes associated with genetic diseases can be amplified by an on-chip polymerase chain reaction (PCR) process automatically. The whole pretreatment process including the leukocytes purification and gDNA extraction can be performed in an automatic fashion with the incorporation of the built bio-separators consisting of microcoils array within less than 20 min. The detection of single nucleotide polymorphism (SNP) genotyping of methylenetetra-hydrofolate reductase (MTHFR) C677T region associated with an increased risk of genetic diseases was further performed to demonstrate the capability of the proposed system. The extracted gDNA can be transported into a micro PCR chamber for on-chip fast nucleic acid amplification of detection genes with minimum human intervention. Hence, the developed system may provide a powerful automated platform for pretreatment of human leukocytes, gDNA extraction and fast analysis of genetic gene.     

L-thiocitrulline. A stereospecific, heme-binding inhibitor of nitric-oxide synthases

Nitric-oxide synthase (NOS) catalyzes the oxidation of L-arginine to citrulline and nitric oxide (NO). The enzyme is inhibited by a variety of N omega-monosubstituted L-arginine analogs, and some of these compounds are useful in reversing pathologies associated with the overproduction of NO (e.g. the hypotension of septic shock). We report here that L-thiocitrulline (gamma-thioureido-L-norvaline) is a potent, stereospecific inhibitor of the constitutive brain and endothelial isoforms of NOS as well as the isoform induced in vascular smooth muscle cells by lipopolysaccharide and interferon-gamma. Steady state kinetic studies show L-thiocitrulline inhibition is competitive with L-arginine (Ki approximately 4-20% of KArgm), indicating that initial binding is as a substrate/product analog. In contrast to L-arginine and N omega-methyl-L-arginine, the prototypic NOS inhibitor, L-thiocitrulline binding elicits a "Type II" difference spectrum, indicating a high spin to low spin transition of the iron in the heme cofactor. This finding suggests that L-thiocitrulline is contributing the sixth ligand to heme iron, probably through the thioureido sulfur. Such interaction with heme iron neither stimulates nor inhibits the direct flavin-mediated cytochrome c reduction activity of the enzyme, but it does inhibit heme-dependent superoxide formation. In vivo, L-thiocitrulline is a potent pressor agent in both normal and endotoxemic rats, the latter finding suggesting utility in treating the hypotension of septic shock.     

Renal amyloidosis in a drug abuser

Drug abusers, particularly those who inject drugs s.c. ("skin popping"), may develop amyloidosis. Chronic infections are thought to play a pathogenetic role in this setting. A patient is presented who had a history of "skin popping" cocaine and heroin and developed nephrotic syndrome, with an elevated serum creatinine and a creatinine clearance of 61 mL/min. Renal biopsy demonstrated amyloidosis. Treatment with colchicine was initiated, and proteinuria decreased to near normal levels after 12 months. Concomitant with the decrease in proteinuria, creatinine clearance improved, although a repeat renal biopsy failed to show any significant improvement in amyloid burden. These observations suggest that colchicine may be a useful treatment in reversing the proteinuria of renal amyloidosis associated with drug abuse. Furthermore, clinical improvement may occur before any demonstrable regression in the amyloidosis.     

Discovery of the ammonium substrate site on glutamine synthetase, a third cation binding site

Glutamine synthetase (GS) catalyzes the ATP-dependent condensation of ammonia and glutamate to yield glutamine, ADP, and inorganic phosphate in the presence of divalent cations. Bacterial GS is an enzyme of 12 identical subunits, arranged in two rings of 6, with the active site between each pair of subunits in a ring. In earlier work, we have reported the locations within the funnel-shaped active site of the substrates glutamate and ATP and of the two divalent cations, but the site for ammonia (or ammonium) has remained elusive. Here we report the discovery by X-ray crystallography of a binding site on GS for monovalent cations, Tl+ and Cs+, which is probably the binding site for the substrate ammonium ion. Fourier difference maps show the following. (1) Tl+ and Cs+ bind at essentially the same site, with ligands being Glu 212, Tyr 179, Asp 50', Ser 53' of the adjacent subunit, and the substrate glutamate. From its position adjacent to the substrate glutamate and the cofactor ADP, we propose that this monovalent cation site is the substrate ammonium ion binding site. This proposal is supported by enzyme kinetics. Our kinetic measurements show that Tl+, Cs+, and NH4+ are competitive inhibitors to NH2OH in the gamma-glutamyl transfer reaction. (2) GS is a trimetallic enzyme containing two divalent cation sites (n1, n2) and one monovalent cation site per subunit. These three closely spaced ions are all at the active site: the distance between n1 and n2 is 6 A, between n1 and Tl+ is 4 A, and between n2 and Tl+ is 7 A. Glu 212 and the substrate glutamate are bridging ligands for the n1 ion and Tl+. (3) The presence of a monovalent cation in this site may enhance the structural stability of GS, because of its effect of balancing the negative charges of the substrate glutamate and its ligands and because of strengthening the "side-to-side" intersubunit interaction through the cation-protein bonding. (4) The presence of the cofactor ADP increases the Tl+ binding to GS because ADP binding induces movement of Asp 50' toward this monovalent cation site, essentially forming the site. This observation supports a two-step mechanism with ordered substrate binding: ATP first binds to GS, then Glu binds and attacks ATP to form gamma-glutamyl phosphate and ADP, which complete the ammonium binding site. The third substrate, an ammonium ion, then binds to GS, and then loses a proton to form the more active species ammonia, which attacks the gamma-glutamyl phosphate to yield Gln. (5) Because the products (Glu or Gln) of the reactions catalyzed by GS are determined by the molecule (water or ammonium) attacking the intermediate gamma-glutamyl phosphate, this negatively charged ammonium binding pocket has been designed naturally for high affinity of ammonium to GS, permitting glutamine synthesis to proceed in aqueous solution.