Self-trapping threshold in disordered nonlinear photonic lattices.

We investigate numerically and experimentally the influence of coupling disorder on the self-trapping dynamics in nonlinear one-dimensional optical waveguide arrays. The existence of a lower and upper bound of the effective average propagation constant allows for a generalized definition of the threshold power for the onset of soliton localization. When compared to perfectly ordered systems, this threshold is found to decrease in the presence of coupling disorder.

Anderson localization in a periodic photonic lattice with a disordered boundary.

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.

Observation of the gradual transition from one-dimensional to two-dimensional Anderson localization.

We study the gradual transition from one-dimensional (1D) to two-dimensional (2D) Anderson localization upon transformation of the dimensionality of disordered waveguide arrays. An effective transition from a 1D to a 2D system is achieved by increasing the number of rows forming the arrays. We observe that, for a given disorder level, Anderson localization becomes weaker with increasing numbers of rows-hence the effective dimension.

Telephone counseling improves adherence to colposcopy among lower-income minority women.

PURPOSE: A randomized trial was conducted to evaluate the impact of a telephone counseling intervention to improve patient adherence to colposcopic examination for suspected cervical intraepithelial neoplasia (CIN). METHODS: Subjects were lower-income, minority women who missed a scheduled initial appointment for colposcopy at an urban medical clinic. Patients were randomly assigned to either a control condition (n = 42) or a telephone counseling condition (n = 48). The 15-minute, structured telephone counseling intervention protocol addressed educational, psychosocial, and practical barriers to colposcopy adherence. RESULTS: The most common patient-reported barriers to colposcopy adherence included a lack of understanding of the purpose of colposcopy (50%), worry about or fear of cancer (25%), and forgetting (23%). Telephone counseling was found to be highly effective in addressing these barriers and improving adherence to diagnostic follow-up and treatment. Of patients in the control condition, 43% complied with a rescheduled colposcopy appointment, compared with 67% in the telephone counseling condition. Logistic regression analysis indicated that the effect of telephone counseling was independent of sociodemographic confounder variables (odds ratio = 2.6; P less than .003). Additionally, 74% of patients who received the initial telephone counseling adhered to recommended treatment, compared with 53% of patients in the control condition. CONCLUSION: Brief, structured telephone contact may be a cost-effective mechanism for improving adherence to diagnostic follow-up and treatment for a variety of cancer screening tests.