Activation of auditory cortex during silent lipreading

Watching a speaker's lips during face-to-face conversation (lipreading) markedly improves speech perception, particularly in noisy conditions. With functional magnetic resonance imaging it was found that these linguistic visual cues are sufficient to activate auditory cortex in normal hearing individuals in the absence of auditory speech sounds. Two further experiments suggest that these auditory cortical areas are not engaged when an individual is viewing nonlinguistic facial movements but appear to be activated by silent meaningless speechlike movements (pseudospeech). This supports psycholinguistic evidence that seen speech influences the perception of heard speech at a prelexical stage.     

Modelling of addition polymerization processes — Free radical,ionic, group transfer,and ziegler–natta kinetics

A brief review of addition polymerization processes is presented with a summary of the key characteristics classified by kinetic mechanism (free-radical, anionic, cationic, group transfer, or Ziegler–Natta), phase behavior, and reactor type. A practical approach to modelling in the industrial R & D environment is discussed in terms of a CAD package for polymerization processes.     

Silicon oxide thin films prepared by a photo-chemical vapour deposition technique

Wide band gap a-SiO_x:H films have been prepared by the photochemical decomposition of a SiH₄, CO₂ and H₂ gas mixture. Deposition parameters namely the CO₂ to SiH₄ gas flow ratio, H₂ dilution and chamber pressure were optimized in order to achieve highly photoconducting (1 × 10^-6 S cm^-1) films with an optical gap of 1.99 eV. The optical gap was found to increase with an increase in the CO₂ to SiH₄ flow ratio. A decrease in the photoconductivity, refractive index, spin g-value and a simultaneous increase in the spin density are attributed to an incorporation of oxygen into the films. Upon hydrogen dilution the photoconductivity of a-SiO_x:H films was observed to improve along with an increase of the optical gap. The spin density of a-SiO_x:H films was of the order of 10¹⁷ cm^-9. The optoelectronic properties of the films have been correlated with the bonding configurations in the film, deposition parameters and the growth kinetics. This revised version was published online in November 2006 with corrections to the Cover Date.     

Proposed modification to the CIECAM02 colour appearance model to include the simultaneous contrast effects

A modified CIECAM02 colour appearance model, named CIECAM02‐m2, is proposed to enable CIECAM02 to predict the simultaneous contrast effect. The structure of the CIECAM02‐m2 is a development from CIECAM02, and contains two different procedures for modifying the reference white; one is for lightness and the other is for hue. The model was tested using a data set accumulated in this study and the LUTCHI data. The CV values for three colour attributes between predictions and experimental data were used to evaluate the accuracy of the model. The low CV values obtained show the performance of the CIECAM02‐m2 model to predict the simultaneous contrast effect satisfactorily. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 121 – 129, 2007     

Monitoring Chemical Changes in Cheddar Cheese During Aging by High Performance Liquid Chromatography and Gas Chromatography Techniques

The concentrations of several chemical metabolites in Cheddar cheese were monitored by various chromatographic techniques during the aging process to learn which metabolites were the best predictors of the glycolytic, lipolytic, and proteolytic age of the cheese. Pyruvic, lactic, acetic, and propionic acids were measured by ion-exchange high performance liquid chromatography; acetone, 2-butanone, ethanol, 2-pentanone, 2-butanol, and n-propanol were monitored by headspace gas chromatography; free fatty acids were quantitated (without derivatization) by gas chromatography; and free amino acids were determined as their o-phthaldehye derivatives by high performance liquid chromatography.The best predictors of the glycolytic age were propionic acid and acetic acid; the best predictors of lipolysis were the free fatty acids C₁₀, C₁₂, C₁₄, and C₁₆; and the best predictors of proteolysis were the free amino acids leucine, methionine, and glutamic acid. The volatile metabolites determined by headspace gas chromatography were not good indicators of aging; however, they did provide useful information related to flavor problems.Cheddar cheese aged at elevated temperatures produced propionic acid, acetic acid, and free amino acids at significantly faster rates than the other chemicals that were monitored.     

A novel endonuclease from kinetoplastid hemoflagellated protozoan parasite Leishmania

A nuclease activity has been purified from the nuclei-kinetoplast fraction of Leishmania. This enzyme, termed endonuclease M (Endo M), is shown by electrophoresis in a denaturing polyacrylamide gel to be associated with a single polypeptide of molecular mass 52 kDa. Physical analysis of the enzyme indicates that it has a sedimentation coefficient S20,w of 4.5S, a Stoke's radius of 32.5 A, and a native molecular mass of 53 kDa. The final Mono Q purified Endo M possesses both DNase and RNase activities. It acts as an endonuclease by introducing random single-stranded nicks into the supercoiled DNA molecules, that often leads to its linearization due to nicking at the opposite strands, and subsequent degradation of the DNA with further incubation. Single-stranded DNA is twice preferred to double-stranded DNA as substrate. Single-stranded RNA is also degraded rapidly and is competitive as a substrate with single-stranded DNA. RNA:DNA hybrids, however, are largely resistant to the Endo M digestion.