Subject characteristics as predictors of self-change in smoking.

Subject characteristics served as predictors of smokers' success or failure in their self-change efforts at smoking cessation over a 6-month period. Seven hundred and three adult subjects represented five stages of change based on the transtheoretical model: precontemplation, contemplation, action, maintenance, and relapse. Step-wise multiple discriminant functions were used to predict movement across the stages. Health problems, problem duration, daily cigarettes, previous attempts to quit, and smoking for pleasure predicted movement through various stages of change. The stronger the smoking habit, the less apt the smoker is to quit or maintain a nonsmoking status. Smokers with higher incomes and more years of education are more likely than persons of lower socioeconomic levels to be successful in their self-change efforts. The advantages of process-oriented rather than static variables for predicting self-change are discussed.

High quality single shot diffraction patterns using ultrashort megaelectron volt electron beams from a radio frequency photoinjector.

Single shot diffraction patterns using a 250-fs-long electron beam have been obtained at the UCLA Pegasus laboratory. High quality images with spatial resolution sufficient to distinguish closely spaced peaks in the Debye-Scherrer ring pattern have been recorded by scattering the 1.6 pC 3.5 MeV electron beam generated in the rf photoinjector off a 100-nm-thick Au foil. Dark current and high emittance particles are removed from the beam before sending it onto the diffraction target using a 1 mm diameter collimating hole. These results open the door to the study of irreversible phase transformations by single shot MeV electron diffraction.