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Efforts to control tobacco use and tobacco related morbidity and mortality in the U.S. have met with reasonable success, at least through the early part of the 1990s. In the 39 years since the publication of the first Surgeon General's Report on Tobacco and Health, adult smoking rates in the U.S. have declined by nearly 40%, although only a modest portion of that decline has occurred during the past decade. Nevertheless, less than a quarter of the U.S. population now smokes and other indices of success, such as changing attitudes toward tobacco use in public places, a near universal perception of tobacco use as a health hazard, and support for laws and regulations restricting tobacco use all point to continued progress in tobacco control among the U.S. adult population.

Analyzes the nonexponential behavior of the kinetics of the initial laser level for three-micron generation in an erbium&sup3+;:YAlO[sub3] crystal under intense pump in the [sup4]S[sub3/2] level. Models used to explain the absence of self-saturation for three-micron room-temperature laser emission; Factor that contributes to the energy transfer to accidental impurities; Type of impurities.

This work reports on the structural changes that take place in wafer grade silicon when it is micro-machined with ultra-short laser pulses of 150 fs duration. A Chirped Pulse Amplification (CPA) Ti:Sapphire laser was used, with an operating wavelength centered on 775 nm and a maximum repetition rate of 1 KHz. The laser induced damage was characterized over the fluence range 0.43-14 J?cm-2, and for each fluence a progressively increasing number of pulses was used. The analytical tools used to characterize the samples were all based upon electron microscopy. A 30 KeV scanning transmission electron microscope (STEM) imaging technique was developed to observe defects in the crystal lattice and the thermal-mechanical damage in the area surrounding the laser machined region. Mechanical cross sectioning (in conjunction with Scanning Electron Microscope (SEM) surface imaging) was also used to reveal the internal structure, composition, and dimensions of the laser machined structures. Based on this analysis, it will be shown that laser machining of silicon with femtosecond pulses can produce features with minimal thermal damage, although lattice damage created by mechanical stresses and the deposition of ablated material both limit the extent to which this can be achieved, particularly with high aspect ratios. A key feature of the work presented here is the high-resolution STEM images of the laser-machined structures. [ABSTRACT FROM AUTHOR]

A randomised trial evaluated the American Cancer Society's telephone counselling service to assist smoking cessation. Counselling nearly doubles a smokers' odds of quitting and maintaining cessation for one year. The estimated cost for each case of maintained smoking cessation attributable to counselling availability is approximately $1300. [ABSTRACT FROM AUTHOR]