Differences in cigarette design and metal content across five countries: results from the International Tobacco Control (ITC) Project.

OBJECTIVES: The current study examines physical cigarette design characteristics and tobacco metal content of cigarettes obtained from 5 countries to determine how these properties vary for cigarette brands, both within and across countries with different dominant manufacturers. METHODS: Cigarette packs were collected from International Tobacco Control Policy Evaluation Survey (ITC) participants in the U.S., the U.K., Mauritius, Mexico, and Thailand. Cigarettes were assessed for physical and design properties (eg, ventilation, pressure drop, rod density, weight) by published methods, and for metal content (As, Cd, Ni, Pb) by X-ray fluorescence spectrometry. RESULTS: Significant differences in cigarette design and toxic metal concentrations were observed between countries and between manufacturers within countries. Filter ventilation, which is strongly predictive of machine-measured tar and nicotine levels, varied most widely across countries. Ni and Cd were highest in Thailand (2.23ug/g and 1.64ug/g, respectively); As was highest in Mexico (0.29ug/g) and Pb was highest in the U.K. (0.43 ug/g). CONCLUSIONS: Parties to the FCTC should consider the adoption of uniform product standards related to cigarette design, emissions, and tobacco content that would reduce population health risks.

Dependence of tar, nicotine and carbon monoxide yields on physical parameters: implications for exposure, emissions control and monitoring.

OBJECTIVE: To estimate the extent to which tar, nicotine and carbon monoxide (TNCO) yields are dependent on cigarette design features such as burn rate, filter ventilation and paper porosity, and to consider the implications for human exposure and the regulation of TNCO emissions. A related aim is to determine whether accurate prediction of TNCO yields is possible using only simple physical parameters. DESIGN AND METHODS: Datasets that include quantitative design parameters as well as measurements of TNCO yields collected under standard conditions with vents unblocked (International Organization for Standardization) and under intense conditions with vents fully blocked (Health Canada) were compiled from the literature (primarily US and UK brands). Forward stepwise multiple regression analysis is used to assess the relative importance of each design feature in explaining variability in the observed emissions. Using randomly split data subsets, multiple linear regression is used to model the dependence of TNCO yields on design features in the training subset and validated against the test subset. Tar and carbon monoxide correlate with many of the particulate- and volatile-phase toxins in smoke, and brand values normalised to nicotine yield are used as surrogate measures of exposure within the bounds defined by non-intense and intense smoking protocols. RESULTS AND CONCLUSIONS: Filter ventilation is the dominant control on measured TNCO emissions, but other factors including burn rate, amount of tobacco and paper porosity also contribute. Yields are predictable with reasonable accuracy and precision using only measured physical parameters. Surrogate exposure indicators suggest that filter ventilation does not lead to any reduction in exposure and that highly ventilated (low-yield) brands may actually increase exposure to the more volatile toxins.

Hybrid optical-digital signal processing applied to an optimal nonlinear phase estimator.

An electrooptical realization of an optimal phase estimator for phase modulated communication signals is described in this work. The realization uses an electrooptical processor to perform a 1-D convolution in a 2-D space and a computer to complete the calculations. The processor is a realization of the time domain recursive nonlinear filter. This paper describes the nonlinear filter theory, the electrooptical realization,and the performance of the processor.

Note of an error in "Action Concept Usage by nonretarded and retarded children on structured tasks with praise for performance".

An error in calculation of MAs of the moderately retarded subjects in the above study raises significant questions about the findings that their use of action concepts is less than that of mildly retarded subjects of the same MA. Their reduced performance may instead be attributable to some unknown extent to their lower MA.

Action-concept learning in retarded children using photographic slides, motion pictures, sequences, and live demonstrations.

The inadequate use of action concepts by mentally retarded children has been reported in several recent studies, but little is yet known concerning the level of performance that might be expected to result from direct instruction designed to remedy this deficit. In the present study, it was found that three different instructional approaches yielded higher adjusted posttest scores. The highest adjusted posttest score was yielded by an instructional program in which motion picture sequences were used. This program was significantly more effective than two paralled programs, one using photographic slides, and the other using live demonstration by a teacher. An explanation for these findings was suggested.

Action-concept usage by nonretarded and retarded children on structured tasks with praise for performance.

In equivalence-formation tasks, retarded children have been ovserved to use fewer action concepts than expected on the basis of their MA. When tasks were structured and praise for performance was introduced, mildly retarded children performed like nonretarded children in most respects, except for total number of responses. Moderately retarded children of the same MA showed improved performance but still performed more poorly than either of the other two groups. The implications of these findings were discussed.