Do teenage magazines give a genuine view of tooth colour?

OBJECTIVES: To compare the colour of incisors depicted in teenage magazines with a sample of Welsh teenagers. MATERIALS AND METHODS: A representative one month sample of magazines aimed at 9- to 16-year-old girls was obtained from a retail outlet. All images containing photographs of anterior teeth were identified and the colour of the incisor teeth measured using two commercial shade guides. An additional category of 'whiter than shade guide' was introduced. Images were viewed under standardised conditions by the same examiner; 10% were repeated. Clinical measurements under standard conditions were taken, by the same examiner, of 9- to 16-year-old children presenting to the department over a one month period, using the same shade guides; 47% of readings were repeated. Data were entered into SPSS and comparison of proportions used to compare the two groups. RESULTS: Nineteen magazines containing 268 images and 53 patients were used. Intra-examiner agreement with the two shade guides was 80% or 92% for patients and 93% or 96% for images. 0/53 (0%) clinical compared with 202/268 (75.4%) photographs were found to be whiter than the shade guide. CONCLUSIONS: Teenage magazines do not give an accurate representation of the colour of teenager's teeth. The impact of this on children's self esteem is unknown.

1-370 GHz EPR linewidths for K3CrO8: a comprehensive test for the Anderson-Weiss model.

Electron paramagnetic resonance (EPR) measurements have been carried out over the frequency range of 1-370 GHz on single crystals of potassium peroxychromate (K3CrO8) with the view of examining the current models of exchange narrowing of EPR signals in solids. K3CrO8 has a simple (tetragonal) lattice structure, can be grown as single crystals pure or diluted with an isostructural diamagnetic host K3NbO8, and its paramagnetism can be described by a very simple (S = 12, I = 0) spin Hamiltonian. The measurements were made at various orientations of single crystals in the Zeeman field, with emphasis on the principal directions of the g-tensor. For essentially all orientations, the linewidth decreases monotonically for measurements at resonance frequencies, omega0, from 1 to about 100 GHz, and then starts to increase at higher omega0. In order to delineate the spin exchange effects from other sources of line broadening, the measurements were repeated with a diluted spin system, K3NbO8 containing approximately/= 0.5 mole % of K3CrO8, representing the broadening effect of all the magnetic field dependent terms, such as the broadening due to the g-strain and sample holder/waveguide magnetization at the high field utilized, up to 14 T. Using these data, the K3CrO8 linewidths were analyzed in terms of the current models of spin exchange narrowing in three-dimensional systems. A reasonably good agreement was found with the Anderson-Weiss model, when modified for various line broadening effects. The accuracy of the analysis procedure was confirmed by the comparison of the presently determined values of the exchange constant, J, and the dipolar field, Hp, with their values obtained by dc magnetic susceptibility measurements and theoretical analysis, respectively; the agreement was within 5% for J (=1.35 K) and about 25% for Hp (160 G). However, some deviations and unusual splittings were noted in measurements at 370 GHz, whose origin remains unclear.

Evaluation of four bioaerosol samplers in the outdoor environment.

INTRODUCTION: A comparative evaluation of four air samplers was performed using bioaerosol collection in the outdoor environment. METHODS: Test samplers used included a Rotorod, a Kramer-Collins suction trap, an all-glass impinger (AGI-30), and a high-volume cyclonic liquid impinger (SpinCon). All samples were analyzed microscopically for spores and pollen. The two collectors providing a liquid sample (AGI-30 and SpinCon) also were analyzed for specific allergen content by enzyme-linked immunoassay. RESULTS: The SpinCon collected a larger number of spores than the other devices. The number of spores collected by this unit per volume of air sampled was comparable to the AGI-30. The Rotorod and Kramer-Collins collected a lower number of spores per unit of air but collected a larger number of pollen grains per volume sampled. Alternaria allergens Alt a I and GP70 were collected by both liquid impingers; however, the SpinCon collected more Alt a I and the AGI-30 collected more GP70. CONCLUSIONS: The SpinCon is a device that is capable of efficiently sampling a high volume of air and concentrating it in a form that can be analyzed for the presence of spores and fungal allergens. It is less useful for collecting intact pollen grains. Pollen allergen quantitation has not yet been performed on the SpinCon effluent.

Designing new substance abuse treatment services for a competitive environment.

A multivariate analysis of the relationships between service attributes and physician perceptions was conducted as an approach to marketing substance abuse treatment services. The results of this attribute-perceptive-preference study indicate: the physician(s) on staff attribute makes the greatest contribution to perceived quality and efficiency; easy referral admission makes the largest contribution to accessibility perceptions; and providing feedback produces the greatest contribution to perceived continuity. The JCAH attributes neither adds to nor subtracts from the perceptions of any of the four perceptual attributes. Other findings indicate that perceived efficiency produces the greatest contribution to overall consumer preference. Quality perceptions make the second largest contribution to overall preference, followed by continuity and accessibility perceptions.