Examining the predictive potential of depressed mood and alcohol misuse on risky driving.

AIMS: Male driving while impaired (DWI) offenders are at heightened risk for engaging in risky driving. Males in a depressed mood are also more prone to alcohol misuse, which may further contribute to risky driving. This manuscript investigates the predictive potential of combined depressed mood and alcohol misuse on risky driving outcomes 3 and 9 years after baseline in male DWI offenders. METHODS: At baseline, participants completed questionnaires assessing depressed mood (Major Depression scale of the Millon Clinical Multiaxial Inventory-III), alcohol misuse (Alcohol Use Disorders Identification Test), and sensation-seeking (Sensation Seeking Scale-V). Risky driving data (Analyse des comportements routiers; ACR3) were collected at follow-up 3 years after baseline. Driving offence data were obtained for 9 years after baseline. RESULTS: There were 129 participants. As 50.4% of the sample were missing ACR3 scores, multiple imputation was conducted. In the final regression model, R2 = 0.34, F(7,121) = 8.76, P < 0.001, alcohol misuse significantly predicted ACR3, B = 0.56, t = 1.96, P = 0.05. Depressed mood, however, did not significantly predict ACR3 and sensation-seeking was not a significant moderator. Although the regression model predicting risky driving offences at Year 9 was significant R2 = 0.37, F(10,108) = 6.41, P < 0.001, neither depressed mood nor alcohol misuse was a significant predictor. CONCLUSIONS: These findings identify alcohol misuse as a predictor of risky driving 3 years after baseline among male DWI offenders. This enhances our prediction of risky driving, extending beyond the widely researched acute impacts of alcohol by exploring chronic patterns.

Multiple Locations of Alcohol Use in the Narratives of the Peruvian Andean Highland and Population with Problem Drinking.

The present qualitative study explores local meanings and modes of interpretation of alcohol use among people with problem drinking in the Peruvian Andean highlands. We conducted individual interviews with 19 people in two districts of Ayacucho region identified as having engaged in problem drinking, using McGill Illness Narrative Interview Schedule. Participants articulated multi-layered associations between alcohol and the body, emotions, social relations, and shared cultural practices and understandings. In the explanatory model of physical distress, participants' problem drinking was often identified as one of the perceived causes or consequences. Moreover, many participants shared their experiences of interpersonal difficulties, such as family disintegration, separation from wife/girlfriend, and conjugal infidelity. These experiences resulted in psychological distress, often described by idioms of distress such as "pensamiento" (constant thinking) and "preocupación" (worrying thought), and the engagement with alcohol. At the same time, alcohol use is situated in participants' daily experience, where past and current interpersonal afflictions intersect with persistent economic hardship and injustice at a larger socio-economic level. Alcohol was seen as instrumental in navigating their social relations as well. Decisions and attitudes toward alcohol use in Ayacucho are shaped in the course of searching for opportunities to build, develop, and maintain interpersonal relationships with friends, colleagues, families, and community members. This study illustrates the importance of understanding the patients' life histories in clinical communication as well as the need for social policies to address the socio-economic determinants of hardship and illness that precipitate alcohol use in the south-central Andean highlands of Peru.

Using fluorescent beads to emulate single fluorophores.

We study the conditions under which fluorescent beads can be used to emulate single fluorescent molecules in the calibration of optical microscopes. Although beads are widely used due to their brightness and easy manipulation, there can be notable differences between the point spread functions (PSFs) they produce and those for single-molecule fluorophores, caused by their different emission patterns and sizes. We study theoretically these differences for various scenarios, e.g., with or without polarization channel splitting, to determine the conditions under which the use of beads as a model for single molecules is valid. We also propose methods to model the blurring due to the size difference and compensate for it to produce PSFs that are more similar to those for single molecules.

Pixel MTF response effect on non-null interferometry.

The pixel modulation transfer function response degrades the contrast of non-null interferometric surface figure measurements. We experimentally quantify this effect for spatial frequencies ranging from 0 to 363 lp/mm (≈3.33 times the Nyquist limit). Our results show a low SNR spatial frequency band that behaves like a low-pass filter for sub-Nyquist interferometry and a stop-band filter for multiple-wavelength phase-shifting interferometry. We also introduce a multiple-mode, multiple-wavelength interferometry approach to measure optical surfaces with slope departure angles mapping to spatial frequencies in this low SNR band. The extended measurement range of this approach is achieved without using a sparse-array detector.

Control, power, and responsibility: a qualitative study of local perspectives on problem drinking in Peruvian Andean highlands.

BACKGROUND: Alcohol control has emerged as an important global health challenge due to the expanding influence of alcohol companies and limited control measures imposed by governments. In the Peruvian Andean highland, the ritual function of collective drinking is reported to have been weakened in response to the increased availability of alcohol and the experience of political violence. This study seeks to merge the broader political economy with local experience and culture to provide a deeper understanding of the dynamic between global processes and local realities. METHODS: We used purposive sampling to recruit participants. We conducted in-depth interviews (n = 28) and focus group discussions (n = 19) with community participants, teachers, health workers, alcohol vendors and police officers. Thematic analysis identified patterns of individual and collective meaning situated in relation to social, political and economic factors. RESULTS: Local perspectives and behaviour regarding loss of control over alcohol are shaped through the complex patterns of power and meaning exerted and experienced by different actors. Participants' emphasis on parents' lack of control over alcohol use by "abandoned" children reflects the structural vulnerability of some Andean families struggling with economic hardships. Participants also emphasized how alcohol consumption was tied to forms of control exerted by men in households. Participants expressed that some men demonstrated their masculine identity and symbolic power as the breadwinner through spending on alcohol. The third emphasis was tied to the market economy. Participants expressed that the expansion of the alcohol market and perceived absence of government control coupled with macroeconomic conditions, like poverty, shaped patterns of alcohol consumption. CONCLUSION: Our findings illustrate how problem drinking is shaped not simply by an individual drinker's lack of self-control but also by a regulatory environment that enables the unrestrained marketing of alcohol products and the creation of a culture of consumption. Harmful consumption is mediated by the reshaping of the Andean cultural practice of collective drinking. Attending to local perspectives is essential for policies and interventions that connect structural dynamics with the cultural and experiential aspects of alcohol consumption.

Theoretical analysis of quantum random walks with stress-engineered optics.

Quantum random walks (QRWs) are random processes in which the resulting probability density of the "walker" state, whose movement is governed by a "coin" state, is described in a nonclassical manner. Previously, Q-plates have been used to demonstrate QRWs with polarization and orbital angular momentum playing the roles of coin and walker states, respectively. In this theoretical analysis, we show how stress-engineered optics can be used to develop new platforms for complex QRWs through relatively simple optical elements. Our work opens up new paths to speed up classical-to-quantum transitions in robust photonic networks.

Simultaneous Measurement of Multiple Parameters of a Subwavelength Structure Based on the Weak Value Formalism.

A mathematical extension of the weak value formalism to the simultaneous measurement of multiple parameters is presented in the context of an optical focused vector beam scatterometry experiment. In this example, preselection and postselection are achieved via spatially varying polarization control, which can be tailored to optimize the sensitivity to parameter variations. Initial experiments for the two-parameter case demonstrate that this method can be used to measure physical parameters with resolutions at least 1000 times smaller than the wavelength of illumination.

The Role of Behavioral Phenotypes on Impaired Driving Recidivism Risk and Treatment Response to Brief Intervention: A Preliminary Study.

BACKGROUND: Heterogeneity in the driving while impaired (DWI) offender population and modest outcomes from remedial programs are fueling interest in clarifying clinically significant DWI subtypes to better assess recidivism risk and target interventions. Our previous research identified 2 putative behavior phenotypes of DWI offenders with distinct behavioral, personality, cognitive, and neurobiological profiles: (i) offenders primarily engaging in DWI (pDWI); and (ii) offenders engaging in DWI and other traffic violations (MIXED). Here, we evaluate these phenotypes' clinical significance for prediction of recidivism and intervention targeting. METHODS: DWI recidivists participating in a previous randomized controlled trial (N = 184 comparing brief motivational interviewing (BMI) and an information and advice control condition (IA) were retrospectively classified as either pDWI (n = 97) or MIXED (n = 87). Secondary analyses then evaluated the effect of this phenotypic classification on self-reported 6- and 12-month alcohol misuse outcomes and documented 5-year DWI recidivism violations, and in response to either BMI or IA (i.e., pDWI-BMI, n = 46; MIXED-BMI, n = 45; pDWI-IA, n = 51; MIXED-IA, n = 42). Two hypotheses were tested: (i) MIXED classification is associated with poorer alcohol misuse outcomes and recidivism outcomes than pDWI classification; and (ii) pDWI paired with BMI is associated with better outcomes compared to MIXED paired with BMI. RESULTS: MIXED classification was associated with significantly greater risk of recidivism over the 5-year follow-up compared to pDWI classification. Moreover, the pDWI-BMI pairing was associated with significantly decreased recidivism risk compared to the MIXED-BMI pairing. Analyses of 6- and 12-month alcohol use outcomes produced null findings. CONCLUSIONS: The clinical significance of phenotypic classification for risk assessment and targeting intervention was partially supported with respect to recidivism risk. Prospective investigation of this and other behavioral phenotypes is indicated.

Polarization singularities in a stress-engineered optic.

We develop a simplified version of a recently presented model to simulate the oblique propagation of polarized light through a thick birefringent element known as a stress-engineered optic (SEO). We use this model to analyze the formation and evolution of three polarization singularities, stars, lemons, and monstars, and experimentally verify the theoretical predictions. We also show how an SEO can be used to generate statistically rare monstar singularities.

Polarization singularities in a stress-engineered optic: erratum.

This erratum gives corrections for the errors in a previously published paper [J. Opt. Soc. Am. A36, 312 (2019)JOAOD60740-323210.1364/JOSAA.36.000312].

Oblique propagation of light through a thick, space-variant birefringent element.

Understanding and modeling the propagation of polarized light through thick, space variant birefringent media is important in both fundamental and applied optics. We present and experimentally evaluate two methods to model the off axis propagation of polarized light through a thick stress-engineered optic (SEO). First, we use a differential equation solving method, which utilizes the analytic expression for the Jones matrix of the SEO leading to a numerical solution for the output electric field. Then we present a geometric method to obtain similar results with much less computational complexity. Finally, a comparison is done between the data and the simulations.

Measuring vector field correlations using diffraction.

We present a method for efficiently measuring the 2 × 2 correlation matrix for paraxial partially coherent beams by using diffraction from small apertures and obstacles. Several representations for this matrix function of four spatial variables are discussed and illustrated with experimental results, including various alternative definitions of the spatial degree of coherence.

Polarized optical scattering by inhomogeneities and surface roughness in an anisotropic thin film.

We extend the theory of Kassam et al. [J. Opt. Soc. Am. A12, 2009 (1995)JOAOD60740-323210.1364/JOSAA.12.002009] for scattering by oblique columnar structure thin films to include the induced form birefringence and the propagation of radiation in those films. We generalize the 4×4 matrix theory of Berreman [J. Opt. Soc. Am.62, 502 (1972)JOSAAH0030-394110.1364/JOSA.62.000502] to include arbitrary sources in the layer, which are necessary to determine the Green function for the inhomogeneous wave equation. We further extend first-order vector perturbation theory for scattering by roughness in the smooth surface limit, when the layer is anisotropic. Scattering by an inhomogeneous medium is approximated by a distorted Born approximation, where effective medium theory is used to determine the effective properties of the medium, and strong fluctuation theory is used to determine the inhomogeneous sources. In this manner, we develop a model for scattering by inhomogeneous films, with anisotropic correlation functions. The results are compared with Mueller matrix bidirectional scattering distribution function measurements for a glancing-angle deposition (GLAD) film. While the results are applied to the GLAD film example, the development of the theory is general enough that it can guide simulations for scattering in other anisotropic thin films.

Star test image-sampling polarimeter.

We present an analysis and test of an image sampling polarimeter based on the concept of Star Test Polarimetry first introduced by Ramkhalawon. The method makes use of a stress engineered optical element (SEO) placed in the pupil plane of an optical system to induce a polarization dependent point spread function (PSF) at the detector. We describe the calibration requirements of the polarimeter and introduce a new algorithm that can robustly extract the Stokes parameters in a single irradiance measurement. By acquiring statistics on the sampled Stokes parameters of a uniformly illuminated pinhole array, we show that a single frame can provide a root mean square angular error of approximately 10 milliradians on the Poincaré sphere.

Phase-space approach to lensless measurements of optical field correlations.

We analyze and test a general approach for efficiently measuring space-variant partially coherent quasi-monochromatic fields using only amplitude masks and free propagation. A phase-space description is presented to analyze approaches of this type and understand their limitations. Three variants of the method are discussed and compared, the first using an aperture mask, the second employing both an obstacle (the exact inverse of the aperture) and a clear mask, and the last combining the previous two. We discuss the advantages and disadvantages of each option.

Single-shot polarimetry imaging of multicore fiber.

We report an experimental test of single-shot polarimetry applied to the problem of real-time monitoring of the output polarization states in each core within a multicore fiber bundle. The technique uses a stress-engineered optical element, together with an analyzer, and provides a point spread function whose shape unambiguously reveals the polarization state of a point source. We implement this technique to monitor, simultaneously and in real time, the output polarization states of up to 180 single-mode fiber cores in both conventional and polarization-maintaining fiber bundles. We demonstrate also that the technique can be used to fully characterize the polarization properties of each individual fiber core, including eigen-polarization states, phase delay, and diattenuation.

A five-year randomized parallel and blinded clinical trial of an extended specialized early intervention vs. regular care in the early phase of psychotic disorders: study protocol.

BACKGROUND: Specialized Early Intervention services (SEI) for first episode psychosis are shown to be effective for the treatment of positive and negative symptoms, medication adherence, rates of relapse, substance abuse disorders, functional outcome and quality of life at two-year treatment follow up. However, it is also reported that these benefits are not maintained when SEI is not sustained. The objective of this trial is to test the efficacy of a 3-year extension of a SEI service (following 2 years of SEI prior to randomization) for the maintenance and consolidation of therapeutic gains as compared to regular care in the community. METHODS: Following an initial 2 years of SEI, patients are randomized to receive either 3-years of continued SEI or regular care. SEI provided at three sites within the McGill network of SEI services, using a model of treatment comprised of: modified assertive case management; psycho education for families; multiple family intervention; cognitive behavioural therapy; and substance abuse treatment and monitoring. Blinded research assistants conduct ongoing evaluation of the outcome variables every three months. The primary outcome measure is remission status measured both as the proportion of patients in complete remission and the mean length of remission achieved following randomization during the additional three years of follow up. Based on preliminary data, it is determined that a total of 212 patients are needed to achieve adequate statistical power. Intent to treat with the last observation carried forward will be the primary method of statistical analysis. DISCUSSION: The "critical period" hypothesis posits that there is a five year window during which the effects of the nascent psychotic illness can be countered and the impact of the disorder on symptomatic and functional outcomes can be offset through active and sustained treatment. Providing SEI throughout this critical period may solidify the benefits of treatment such that gains may be more sustainable over time as compared to intervention delivered for a shorter period. Findings from this study will have implications for service provision in first episode psychosis. TRIAL REGISTRATION: ISRCTN11889976.

Using shadows to measure spatial coherence.

We present a very simple method for measuring the spatial coherence of quasi-monochromatic fields through the comparison of two measurements of the radiant intensity with and without a small obscuration at the test plane. From these measurements one can measure simultaneously the field's coherence at all pairs of points whose centroid is the centroid of the obstacle. This method can be implemented without the need of any refractive or diffractive focusing elements.

A device for magnetic-field angle control in magneto-optical filters using a solenoid-permanent magnet pair.

Atomic bandpass filters are used in a variety of applications due to their narrow bandwidths and high transmission at specific frequencies. Predominantly, these filters are in the Faraday (Voigt) geometry, using an applied axial (transverse) magnetic field with respect to the laser propagation direction. Recently, there has been interest in filters realized with arbitrary-angle magnetic fields, which have been made by rotating permanent magnets with respect to the k-vector of the interrogating laser beam. However, the magnetic field angle achievable with this method is limited as field uniformity across the cell decreases as the rotation angle increases. In this work, we propose and demonstrate a new method of generating an arbitrary-angle magnetic field, using a solenoid to produce a small, and easily alterable, axial field, in conjunction with fixed permanent magnets to produce a large transverse field. We directly measure the fields produced by both methods, finding them to be very similar over the length of the vapor cell. We then compare the transmission profiles of filters produced using both methods, again finding excellent agreement. Finally, we demonstrate the sensitivity of the filter profile to changing magnetic field angle (solenoid current), which becomes easier to exploit with the much improved angle control and precision offered by our new design.

Imaging the polarization of a light field.

We describe and analyze a method by which an optical polarization state is mapped to an image sensor. When placed in a Bayesian framework, the analysis allows a priori information about the polarization state to be introduced into the measurement. We show that when such a measurement is applied to a single photon, it eliminates exactly one fully polarized state, offering an important insight about the information gained from a single photon polarization measurement.