Smooth Frame-Path Termination for Higher Order Sigma-Delta Quantization

We study the performance of finite frames for the encoding of vectors by applying standard higher-order sigma-delta quantization to the frame coefficients. Our results are valid for any quantizer with accuracy ε > 0 operating in the no-overload regime. The frames under consideration are obtained from regular sampling of a path in a Hilbert space. In order to achieve error bounds that are comparable to results on higher-order sigma-delta for the quantization of oversampled bandlimited functions, we construct frame paths that terminate smoothly in the zero vector, that is, with an appropriate number of vanishing derivatives at the endpoint.     

Sensitivity of the population of states to the value of q and legitimate range of q in Tsallis statistics

In the framework of the Tsallis statistical mechanics, we study the change of the population of states when the parameter q is varied, for some model systems; the results show that the difference between predictions of the Boltzmann-Gibbs and Tsallis statistics can be much smaller than the precision of any existing experiment. Also, the relation between privilege of rare and frequent events and the value of q is restudied. It is shown that positive q privilege frequent and negative q privilege rare events. Finally, the convergence criteria of the partition function of some simple model systems, in the framework of Tsallis statistical mechanics, is studied. Based on this study, we conjecture that q = 1, in the thermodynamic limit.     

Standards and their influence on MAC bridges

The influence that consensus standards have had on the development of media access control (MAC) bridges is examined. The intent is to give an intuitive feel for the standards process and its effect on bridges without detailing the specific groups and processes associated with the standards organizations. It is shown that standards developed under the consensus procedure must follow a certain pattern     

Effect of model potential of adsorptive bond on the thermodynamic properties of adsorbed CO molecules on Ni(111) surface

The effect of anharmonicity on the adsorption of CO molecules on the Ni(111) surface has been investigated. The DFT calculations are used to obtain the effective adsorption potential of the CO molecule on the Ni(111) surface. First, using an appropriate slab model, the geometry of adsorption system corresponding to hcp, fcc, bridge, and on-top sites with p(2 x 2) arrangement and coverage of 0.25 ML is optimized by the DFT calculations using a plane wave basis set and ultrasoft pseudopotentials; this gives the hcp site as the most stable site with De = 185 kJ/mol, for which the equilibrium distance of CO from the surface and C-O bond length on the surface are found to be 1.31 and 1.192 A, respectively. Then, the potential function of adsorption versus adsorptive bond distance was plotted, which is significantly different from that of a harmonic oscillator, i.e., the anharmonicity for the adsorptive bond is significant. Also the harmonic and anharmonic shifts of vibrational frequencies of adsorptive and C-O bonds are calculated to be -22.6 and 7.8 cm(-1), respectively. Hence, two potential models are selected for which their Schr?dinger equations are solved analytically, namely the hard repulsion-soft attraction (HS) and Morse potential (MP) models. The adsorption isotherms, internal energy, isochoric heat capacity, and entropy of adsorbed CO molecules have been calculated for the mentioned model potentials and compared with those of the harmonic oscillator (H). As a result, the adsorption isotherms are not considerably sensitive to the model potential. The anharmonicity of CO-Ni bond, which is included in HS and MP models, gives an average deviation in pressure as much as 1.4% for HS and 5.8% for MP, compared to 6.1% for the H model. However, isochoric heat capacity and entropy depend on the model potential significantly, and the differences may be as high as 69% and 55% for isochoric heat capacity and entropy, respectively.     

Therapeutic Versus Preventative Use of Ginkgo biloba Extract (EGb 761) against Indomethacin-Induced Gastric Ulcer in Mice

The main bioactive constituents in the standardized Ginkgo biloba leaf extract (EGb 761) are the terpene lactones and flavonoid glycosides. EGb 761’s antioxidant and anti-inflammatory properties have previously been demonstrated. Indomethacin-induced gastric ulcers have a multifactorial etiology and represent a major restriction to its therapeutic utility. The underlying ulcerogenic process involves oxidative and inflammatory biomolecular insults. This study was performed to explore the curative and preventative benefits of EGb 761 in experimentally-induced ulcers. To develop gastric ulcers in mice, indomethacin (40 mg/kg) was administered orally. EGb 761 (200 mg/kg) was given by gavage for 7 days before (preventative) and after (therapeutic) indomethacin administration. The histological alterations and macroscopic mucosal lesions were assessed. In gastric tissue homogenates, malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), and inflammatory cytokines were measured. The expressions of cyclooxygenase-2 (COX-2), cytokines, and proliferating cell nuclear antigen (PCNA) in the stomach mucosa were also investigated. The ulcer index, histological alterations, gastric oxidants, and inflammatory biomarkers were all significantly increased by indomethacin. In stomach specimens, it increased COX-2 and PCNA expression. EGb 761 treatments, both prophylactic and therapeutic, resulted in significant reductions in ulcer lesions, nitrosative and oxidative damage, and inflammatory markers, along with the lowering of COX-2 and PCNA expressions. Furthermore, in the fight against stomach ulcers, EGb 761 treatment was found to be more efficient than prevention.     

Bio-Cyber Interface Parameter Estimation with Neural Network for the Internet of Bio-Nano Things

Wireless Personal Communications - Recently, there is growing interest in the Internet of Bio-Nano Things (IoBNT) based on biological communication with the advent of communication engineering and...     

Mentha longifolia subsp. typhoides and subsp. schimperi: Antimicrobial and Antiquorum-Sensing Bioactivities

Chemistry of Natural Compounds -     

Speech intelligibility in free field: spatial unmasking in preschool children

This study introduces a new test (CRISP-Jr.) for measuring speech intelligibility and spatial release from masking (SRM) in young children ages 2.5-4 years. Study 1 examined whether thresholds, masking, and SRM obtained with a test designed for older children (CRISP) and CRISP-Jr. are comparable in 4 to 5-year-old children. Thresholds were measured for target speech in front, in quiet, and with a different-sex masker either in front or on the right. CRISP-Jr. yielded higher speech reception thresholds (SRTs) than CRISP, but the amount of masking and SRM did not differ across the tests. In study 2, CRISP-Jr. was extended to a group of 3-year-old children. Results showed that while SRTs were higher in the younger group, there were no age differences in masking and SRM. These findings indicate that children as young as 3 years old are able to use spatial cues in sound source segregation, which suggests that some of the auditory mechanisms that mediate this ability develop early in life. In addition, the findings suggest that measures of SRM in young children are not limited to a particular set of stimuli. These tests have potentially useful applications in clinical settings, where bilateral fittings of amplification devices are evaluated.     

Spectroscopic, thermal and antitumor investigations of sulfasalazine drug in situ complexation with alkaline earth metal ions

The complexes of sulfasalazine (H₃Suz) with some of alkaline metals Mg(II), Ca(II), Sr(II) and Ba(II) have been investigated. Sulfasalazine complexes were synthesized and characterized by spectroscopic tools; infrared spectra, electronic and mass spectra. The IR spectra of the prepared complexes were suggested that the H₃Suz behaves as a bi-dentate ligand through the carboxylic and phenolic groups. The molar conductance measurements gave an idea about the non-electrolytic behavior of the H₃Suz complexes. The thermal decomposition processes for metal(II) complexes of H₃Suz viz: [M(HSuz)(H₂O)₄] (where M = Mg(II), Ca(II), Sr(II) or Ba(II)) have been accomplished on the basis of TG/DTG and DTA studies, and the formula conforms to the stoichiometry of the complexes based on elemental analysis. The kinetic analyses of the thermal decomposition were studied using the Coats–Redfern and Horowitz–Metzger equations. The antitumor and antimicrobial activities of the H₃Suz and their alkaline metal(II) complexes were evaluated.