Reaction of cytochrome P450 with cumene hydroperoxide: ESR spin-trapping evidence for the homolytic scission of the peroxide O-O bond by ferric cytochrome P450 1A2

ESR spin trapping was used to investigate the reaction of rabbit cytochrome P450 (P450) 1A2 with cumene hydroperoxide. Cumene hydroperoxide-derived peroxyl, alkoxyl, and carbon-centered radicals were formed and trapped during the reaction. The relative contributions of each radical adduct to the composite ESR spectrum were influenced by the concentration of the spin trap. Computer simulation of the experimental data obtained at various 5,5-dimethyl-1-pyrroline N-oxide (DMPO) concentrations was used to quantitate the contributions of each radical adduct to the composite ESR spectrum. The alkoxyl radical was the initial radical produced during the reaction. Experiments with 2-methyl-2-nitrosopropane identified the carbon-centered adducts as those of the methyl radical, hydroxymethyl radical, and a secondary carbon-centered radical. The reaction did not require NADPH-cytochrome P450 reductase or NADPH. It is concluded that the reaction involves the initial homolytic scission of the peroxide O-O bond to produce the cumoxyl radical. Methyl radicals were produced from the beta-scission of the cumoxyl radical. The peroxyl adduct was not observed in the absence of molecular oxygen. We conclude that the DMPO peroxyl radical adduct detected in the presence of oxygen was due to the methylperoxyl radical formed by the reaction of the methyl radical with oxygen. At a higher P450 concentration, a protein-derived radical adduct was also detected.     

A broad line n.m.r. study of oriented poly(vinylidene fluoride)

Broadline nuclear magnetic resonance measurements have been carried out for the proton resonance in oriented poly(vinylidene fluoride). The spectra in general show two component lines with distinctly different line widths. The broad component shows a high degree of molecular orientation and can be satisfactorily assigned to the crystalline regions of the polymer. The narrow component corresponds to an oriented non crystalline phase which is sufficiently constrained to allow motion about the chain axis only. An appreciable decrease in the value of the rigid mass fraction was observed in both of the samples over the temperature range examined. Our calculations indicate that this could play an important role in the temperature dependence of the pyroelectric response of this material.     

Uncooled DBR laser directly Modulated at 3.125 gb/s as athermal transmitter for low-cost WDM systems

An uncooled three-section tunable distributed Bragg reflector laser is demonstrated as an athermal transmitter for low-cost uncooled wavelength-division-multiplexing (WDM) systems with tight channel spacing. A /spl plusmn/0.02-nm thermal wavelength drift is achieved under continuous-wave operation up to 70/spl deg/C. Dynamic sidemode suppression ratio of greater than 35 dB is consistently obtained under 3.125-Gb/s direct modulation over a 20/spl deg/C-70/spl deg/C temperature range, with wavelength variation of as low as /spl plusmn/0.2 nm. This indicates that more than an order of magnitude reduction in coarse WDM channel spacing is possible using this source.     

Contamination of facial memory through exposure to misleading composite pictures.

In Exp I, 46 male and 51 female undergraduates witnessed a filmed incident and later described the target. Results show that Ss who observed a composite containing misleading information (either incorrect hair or an added moustache) were significantly more likely to misreport hairstyle and the presence of a moustache than those who did not. In Exp II, 210 17–65 yr old Ss observed a filmed incident and were tested for their recall and recognition of the target either immediately or after delays of 2 or 7 days. Significant bias, consistent with the content of the misleading composite, was present for both cued recall and choice of mug shot in a photo spread. The effect did not increase over delay but was greater when the composite was seen just prior to recall than immediately after the incident. Implications concerning interference with the memory of the witness who produced the composite and for other witnesses exposed to the misleading composite are discussed. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Development of Color Categories in Two Languages: A Longitudinal Study.

This study unites investigations into the linguistic relativity of color categories with research on children's category acquisition. Naming, comprehension, and memory for colors were tracked in 2 populations over a 3-year period. Children from a seminomadic equatorial African culture, whose language contains 5 color terms, were compared with a group of English children. Despite differences in visual environment, language, and education, they showed similar patterns of term acquisition. Both groups acquired color vocabulary slowly and with great individual variation. Those knowing no color terms made recognition errors based on perceptual distance, and the influence of naming on memory increased with age. An initial perceptually driven color continuum appears to be progressively organized into sets appropriate to each culture and language. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A site selection model for high technology manufacturing firms in the United States

This article offers a quantitative model for site selection by high technology manufacturing firms. In the past, site selection studies have usually been qualitative in nature, and very subjective. This is an attempt to introduce a more objective quantitative approach. The site selection factors most important to high technology manufacturing firms were identified, ranked and weighted based on a US Joint Economic Committe survey of such firms. The eight most important factors were: the availability of technical and professional workers, labor costs, tax climate, academic institutions, cost of living, transportation for people, and access to markets. Demographic data on these factors were collected and analyzed for 32 developing high technology areas in the United States. By using the quantitative model, a score was developed for each area, allowing them to be ranked as R & D manufacturing environments. This model should prove a useful tool for both regional planners and high-tech companies seeking to relocate.     

Health status of the over 60 years of age population and its relationship with sociodemographic factors (ANCO Project)

OBJECTIVE: To describe the health status of a population over 60 years and to study their relationship with several socio-demographic variables. DESIGN: A cross-sectional study, population based. SETTINGS: A community. PARTICIPANTS: A randomized sample of 1,103 non institutionalized people over 60 years living in the city of Cordoba (Spain). MEASUREMENTS AND MAIN RESULTS: By mean of a personal interview at home we used the OARS-MFAQ-VE questionnaire. Low self-rated health was associated with the age, to be female sex, a low cultural background, and a low income. Only 5.2% of the study people do not suffered any illness and 56% state that their health problems are major problems for doing their current activities. 4.9% declared to have some degree of physical incapacity. 3.7% of elderly population has an important cognitive deficit. CONCLUSIONS: The majority of elderly people has good health. Age is related with a poor health. Women have more health problems than men.