The interaction between gaze and facial expression in the amygdala and extended amygdala is modulated by anxiety

Behavioral evidence indicates that angry faces are seen as more threatening, and elicit greater anxiety, when directed at the observer, whereas the influence of gaze on the processing of fearful faces is less consistent. Recent research has also found inconsistent effects of expression and gaze direction on the amygdala response to facial signals of threat. However, such studies have failed to consider the important influence of anxiety on the response to signals of threat; an influence that is well established in behavioral research and recent neuroimaging studies. Here, we investigated the way in which individual differences in anxiety would influence the interactive effect of gaze and expression on the response to angry and fearful faces in the human extended amygdala. Participants viewed images of fearful, angry and neutral faces, either displaying an averted or direct gaze. We found that state anxiety predicted an increased response in the dorsal amygdala/substantia innominata (SI) to angry faces when gazing at, relative to away from the observer. By contrast, high state anxious individuals showed an increased amygdala response to fearful faces that was less dependent on gaze. In addition, the relationship between state anxiety and gaze on emotional intensity ratings mirrored the relationship between anxiety and the amygdala/SI response. These results have implications for understanding the functional role of the amygdala and extended amygdala in processing signals of threat, and are consistent with the proposed role of this region in coding the relevance or significance of a stimulus to the observer

Electro-optic adaptive microlens

The goal of the present research was to demonstrate the viability of an electro-optic adaptive microlens (EOAM) system in imaging applications requiring broadband illumination in the visible region. Previous works illustrate devices that are adaptive optics but are limited in capability. Most have been designed and optimized for a particular wavelength and many of them are polarization dependent. An adaptive optical system that will function over a broadband of visible wavelengths will be useful in many imaging applications. The tasks completed for EOAM system design and build required understanding and implementation of the imaging theory, the materials\u27 properties, the control voltages, the fabrication processes, and finally understanding and implementation of the imaging theory for testing. Single cell transmission devices were used for initial characterization of the polymer-dispersed liquid crystal (PDLC) process. Three iterations of the EOAM devices with PDLC were built on silicon wafers and 26 devices were optically tested. The new chemical mechanical planarization process was implemented for the second and third builds. For optical device testing the phase shift was extracted using a newly developed method for blind phase extraction. The development of a design model for the EOAM system and validating it with the images formed by a real electro-optic adaptive microlens system has provided the knowledge base needed for implementation of adaptive electro-optic lenses for the visible region, and a process which can be used for further improvement of the microsystem. The model parameters can be adjusted for new electro-optic materials that may become available that do not have the limitations of PDLC

Study of the wear of dental composites using an atomic force microscope

This work presents a study of the wear of four dental composites (Concept, XRV, Maxxim, and Belleglass) which are in commercial use. The wear testing was performed using an Atomic Force Microscope (AFM). Several scanning techniques and various cantilevers were attempted. Finally use of a stainless steel cantilever with a tungsten bead attached resulted in quantifiable wear. AFM imaging in contact mode was used for evaluation of the wear tests. Wear rates are reported as volume per 100,000 scans. The AFM measured wear rates rank the tested composites from most to least wear as follows: Concept highest volume of wear XRV Maxxim BelleGlass least volume of wear. Micro-hardness measurements were also conducted

What Happens to College Debaters?

Preliminary report by H.L.Ewbank on alumni and members of Delta Sigma Rho

Optical thickness as related to pollutant episodes and the concentration of visibility degrading pollutants

A network of six sun photometers was placed in the central and northeast United States during the months of July through October, 1931. The objective of the program was to obtain measurements of atmospheric turbidity which can be related to the concentration of visibility-degrading pollutants in the atmosphere. These measurements serve as ground truth for a program to develop remote sensing techniques for measuring the vertically integrated aerosol concentrations in pollution episodes. The sun photometers measure the direct solar radiation in four passbands: 380 nm, 500 nm, 875 nm and 940 nm. The first three passbands will be used for measuring the aerosol optical depth and the last for measuring precipitable water

Alzheimer’s Disease as a Cause of Death in the U.S.: Estimates and Projections

The phrase the demography of Alzheimer\u27s disease may be the best litmus test to distinguish demographers from epidemiologists. A typical reaction to this phrase from a demographer is why Alzheimer\u27s disease? A typical reaction from an epidemiologist is why demography? It is always tricky to describe the exact boundaries that separate two similar disciplines and this is especially true of the difference between demographic and epidemiologic approaches to mortality and health. What made Preston\u27s work on smoking and mortality demography rather than epidemiology? What differentiates a demographer\u27s or a sociologist\u27s work on factors affecting residence in nursing homes from an epidemiologist\u27s work on the same topic