INTEGRATIVE BAYESIAN ANALYSIS OF NEUROIMAGING-GENETIC DATA THROUGH HIERARCHICAL DIMENSION REDUCTION.

Advances in neuromedicine have emerged from endeavors to elucidate the distinct genetic factors that influence the changes in brain structure that underlie various neurological conditions. We present a framework for examining the extent to which genetic factors impact imaging phenotypes described by voxel-wise measurements organized into collections of functionally relevant regions of interest (ROIs) that span the entire brain. Statistically, the integration of neuroimaging and genetic data is challenging. Because genetic variants are expected to impact different regions of the brain, an appropriate method of inference must simultaneously account for spatial dependence and model uncertainty. Our proposed framework combines feature extraction using generalized principal component analysis to account for inherent short- and long-range structural dependencies with Bayesian model averaging to effectuate variable selection in the presence of multiple genetic variants. The methods are demonstrated on a cocaine dependence study to identify ROIs associated with genetic factors that impact diffusion parameters.

On the measurement of the Pockels effect in strained silicon.

We measure the voltage-dependent phase shift in silicon waveguides strained by a silicon nitride layer and show that, in our measurements, the phase shift is due to free carrier accumulation inside the waveguides. Nonetheless, inverting the applied voltage also inverts the applied phase shift-an effect due to a quasi-static surface charge in the silicon nitride. Since the measured effect is on the same order as recently published second-order nonlinearities attributed to the Pockels effect, inclusion of these carrier-based effects in the analysis of experimental data is of paramount importance.

Optical peaking enhancement in high-speed ring modulators.

Ring resonator modulators (RRM) combine extreme compactness, low power consumption and wavelength division multiplexing functionality, making them a frontrunner for addressing the scalability requirements of short distance optical links. To extend data rates beyond the classically assumed bandwidth capability, we derive and experimentally verify closed form equations of the electro-optic response and asymmetric side band generation resulting from inherent transient time dynamics and leverage these to significantly improve device performance. An equivalent circuit description with a commonly used peaking amplifier model allows straightforward assessment of the effect on existing communication system architectures. A small signal analytical expression of peaking in the electro-optic response of RRMs is derived and used to extend the electro-optic bandwidth of the device above 40 GHz as well as to open eye diagrams penalized by intersymbol interference at 32, 40 and 44 Gbps. Predicted peaking and asymmetric side band generation are in excellent agreement with experiments.

Comparison of dysfunctional attitudes and social adjustment among infertile employed and unemployed women in Iran.

This study aims to compare dysfunctional attitudes and social adjustment in infertile employed and unemployed females. Due to the stresses of infertility, infertile females are faced with a variety of sexual and psychological problems, as well as dysfunctional attitudes that can lead to depression. Moreover, infertility problems provoke women into maladjustment and inadvertent corruption of relationships. In this regard, our goal is to consider the effects of employment in conjunction with education on dysfunctional attitudes and social adjustment among infertile women in Iran. In this work, we employed the survey method. We recruited 240 infertile women, utilizing the cluster random sampling method. These women filled out the Dysfunctional Attitudes Scale and the social adjustment part of the California Test of Personality. Next, multivariate analysis of variance was performed to test the relationship of employment status and education with dysfunctional attitudes and social adjustment. Our results indicated that dysfunctional attitudes were far more prevalent in infertile unemployed women than in infertile employed women. Also, social adjustment was better in infertile employed women than in infertile unemployed women. It was shown that education level alone does not have significant effect on dysfunctional attitudes and social adjustment. However, we demonstrated that the employment status of infertile women in conjunction with their education level significantly affects the two dimensions of dysfunctional attitudes (relationships, entitlements) and has insignificant effects on social adjustment. It was revealed that in employed infertile women in Iran, the higher education level, the less dysfunctional were attitudes in relationships and entitlements, whereas in unemployed infertile women, those with a college degree had the least and those with master's or higher degrees had the most dysfunctional attitudes in terms of relationships and entitlements.

Screening for celiac disease in diabetic children from Iran.

Celiac disease has been shown to be associated with type 1 diabetes mellitus. We conducted this study to determine the frequency of celiac disease in a group of Iranian diabetic children. Ninety-six patients with type 1 diabetes mellitus were tested for anti-tissue transglutaminase antibodies. Six patients (6.25%) were seropositive, and histopathological changes were compatible with celiac disease in intestinal biopsy.