Families of 54 behaviorally disturbed preschool-aged children (3 to 5 years) were randomly assigned to 1 of 3 treatment conditions: standard parent-child interaction therapy (PCIT; STD); modified PCIT that used didactic videotapes, telephone consultations, and face-to-face sessions to abbreviate treatment; and a no-treatment waitlist control group (WL). Twenty-one nondisturbed preschoolers were recruited as a social validation comparison condition. Posttreatment assessment indicated significant differences in parent-reported externalizing behavior in children, and parental stress and discipline practices from both treatment groups on most measures compared with the WL group. Clinical significance testing suggested a superior effect for the STD immediately after intervention, but by 6-month follow-up, the two groups were comparable. The findings indicate that abbreviated PCIT may be of benefit for families with young conduct problem children.

The long-term effect of two parent training programs for conduct problem preschoolers is reported. Families of 54 behaviorally disturbed preschool-aged children were randomly assigned to 1 of 3 treatment conditions: standard Parent-Child Interaction Therapy (STD), an abbreviated form of PCIT (ABB), and a no-treatment waitlist control group (WL). Of the families who completed treatment (STD and ABB), data were collected on 97% and 94% of families at 1- and 2-year follow-up, respectively. Follow-up assessment of parent report and independent observations indicated that treatment gains were largely maintained for both treatment conditions with little difference between the two treatments. The findings suggest that an abbreviated form of PCIT has long-term benefits for families with young children displaying early conduct problems.

Economically and technically viable methods for controlling paraffin buildup in pipelines and wellbores are critical to the production of crude oil in deep water and cold environments. Conoco has identified laboratory test methods and developed a paraffin prediction program to better quantify the paraffin (wax) deposition potential of a crude oil and to evaluate or develop methods of preventing or controlling paraffin buildup. This paper will describe the thermodynamic paraffin model and the complementary laboratory test methods. A companion paper will describe the kinetic deposition model and the associated laboratory and field data.

No abstract

Economically and technically viable methods for controlling paraffin buildup in pipelines and wellbores are critical to the production of crude oil in deep water and cold environments. Laboratory test methods and a computational model have been developed to predict rates of paraffin deposition in pipelines and the effect of long-term deposition on the pipeline pressure drop and temperature profile. The model has been incorporated into a fully menu-driven program that runs on a personal computer. The two major portions of the program are the thermodynamic model which is used to calculate solid-liquid-vapor phase equilibria and the kinetic model which is used to predict the deposition and paraffin buildup rates. The thermodynamic portion is described in a companion paper'.The kinetic model is based on information present in the literature and on several hundred measurements of paraffin deposition rates in a laboratoryscale test loop.

A thermodynamic model for paraffin formation is presented which accurately accounts for the effects of light ends, such as methane, ethane, and propane, and high pressures. The model uses the Simplified, Perturbed Hard Chain equation of state for all fluid phase fugacities and contains no adjustable parameters for the solid-liquid equilibria. Model predictions are compared to binary solid-liquid, solid-vapor, and solid-liquid-vapor equilibria data with good results. Also, a high-pressure, coldstage microscope technique was developed to measure cloud points of live oils with which to test the model. Comparisons between the predicted and measured cloud points for live oils are presented.

Purpose The aim of this study was to determine how laser in situ keratomileusis (LASIK) affects quality of life (QOL) and to identify factors that may affect satisfaction after LASIK. Methods A total of 104 patients with a mean age of 29±6, treated with LASIK for myopia and astigmatism, were enrolled in a prospective study. High (90%) and low (10%) contrast visual acuity (CVA) were measured under photopic and scotopic conditions before surgery and at 3 months later. A multidimensional QOL scale (Institute for Eye Research multidimensional QOL scale), which assesses psychological characteristics, personality traits, cosmesis, frequency, and tolerance to disturbing visual and ocular symptoms, and overall satisfaction with vision correction, was also used. Paired rank tests were used to compare preoperative and postoperative vision and QOL scores. Correlations and a multiple linear regression were used to describe the relationship between CVA, QOL, and satisfaction after LASIK. Results Significant postoperative changes included increased satisfaction following LASIK (Po0.001), reduced frequency of visual and ocular symptoms (Po0.001), and change in psychological characteristics (P ¼ 0.033). The change in satisfaction with LASIK can be predicted by a combination of preoperative satisfaction, postoperative frequency of disturbing visual and ocular symptoms, postoperative mean spherical equivalent, and postoperative scotopic high CVA (R 2 ¼ 0.725, Po0.05). Conclusions Satisfaction with LASIK is related to visual function, preoperative expectations, psychological characteristics, and uncorrected CVA achieved. An increased sense of subjective well-being, adaptability, and self-efficacy was evident after LASIK. Patients reported a more optimistic attitude to life and increase perceived QOL after surgery.

No abstract