Shot noise in gravitational-wave detectors with Fabry-Perot arms

Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry-Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian-French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the 40-m arms.     

The relationship between coping styles, performance, and responses to stressful scenarios in police recruits.

This study investigated the relationship between coping styles and police recruits' stress responses and performance during a stressful event and the relationship between coping styles and traumatic symptoms. Recruits participated in a simulated stressful policing situation and were scored by expert raters. Distress measures included biological and psychological indicators of stress. Coping styles were associated with subjective and physiological distress but not with performance. Different coping styles were associated with different patterns of traumatic symptoms in the participants. Police recruits appear to rely on their training and skill sets in stressful situations regardless of how they manage their emotional response. Furthermore, the results suggest that different posttraumatic stress disorder manifestations may represent different pathologies, each associated with a different style of coping. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mental rotation of representations of two-dimensional and three-dimensional objects.

Empirical and theoretical considerations suggest that representations of three-dimensional objects should be more difficult to rotate mentally than representations of two-dimensional objects. In this study, subjects were asked to make mirror-normal decisions with stimuli that differed in perceived dimensionality and in angle of rotation in the image plane. In a series of four experiments, the time to make mirror-normal decisions increased with increased orientation discrepancy between the stimuli, as found previously in the literature. In every experiment, however, response times were smaller for representations of two-dimensional shapes than for representations of three-dimensional shapes when the stimuli being compared were presented with a large angular discrepancy. Whereas response times increased linearly with orientation when representations of three-dimensional shapes were rotated, the increase in response time for representations of two-dimensional shapes was generally nonlinear. Overall, the evidence suggests that representations of three-dimensional shapes are mentally rotated at the same rate as representations of two-dimensional shapes for angles of rotation between 0° and 60°. For larger angles of rotation, however, the rate of mental rotation is greater for representations of two-dimensional shapes than for representations of three-dimensional shapes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paradoxical effects of interprofessional briefings on OR team performance

Our recent research has found that structured preoperative team briefings can reduce communication failures, improve the knowledge and practice of operating room (OR) team members, and garner broad support from surgeons, nurses, and anesthesiologists. However, we have also encountered challenges and unexpected, negative effects. Using qualitative analysis of fieldnotes from 302 preoperative team briefings, we identified five paradoxical findings: team briefings could mask knowledge gaps, disrupt positive communication, reinforce professional divisions, create tension, and perpetuate a problematic culture. Fifteen percent of the briefings exhibited only these paradoxical effects without any apparent utility. We describe these paradoxical findings and analyze them in relation to educational, functional, structural, and cultural factors. This analysis is instructive not only for re-engineering the briefing process, but also for revealing dynamics that may continue to impede optimal interprofessional performance.     

Dynamic models of Fabry-Perot interferometers

Long-baseline, high-finesse Fabry-Perot interferometers can be used to make distance measurements that are precise enough to detect gravity waves. This level of sensitivity is achieved in part when the interferometer mirrors are isolated dynamically, with pendulum mounts and high-bandwidth cavity length control servos to reduce the effects of seismic noise. We present dynamical models of the cavity fields and signals of Fabry-Perot interferometers for use in the design and evaluation of length control systems for gravity-wave detectors. Models are described and compared with experimental data.     

The genetic aspects of developmental dyslexia.

Discusses evidence concerning genetic influences on developmental dyslexia, a disorder characterized by difficulty in learning to read despite adequate opportunity and intelligence. Research on familial incidence, concordance in twins, the influence of parental age at the child's birth, and the subtyping of dyslexics is summarized. It is concluded that there is strong evidence for the heritability of a subtype based on verbal/language deficiency, perhaps reflecting reversed cerebral asymmetry, for which a genetic marker has been found. It is uncertain whether this subtype is caused by left hemispheric impairment or immaturity. There is somewhat weaker evidence for the heritability of a subtype based on visual/spatial deficiencies and a mixed subtype. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

White-light interferometry using a channeled spectrum. 2. Calibration methods, numerical and experimental results

In the companion paper, [Appl. Opt. 46, 5853 (2007)] a highly accurate white light interference model was developed from just a few key parameters characterized in terms of various moments of the source and instrument transmission function. We develop and implement the end-to-end process of calibrating these moment parameters together with the differential dispersion of the instrument and applying them to the algorithms developed in the companion paper. The calibration procedure developed herein is based on first obtaining the standard monochromatic parameters at the pixel level: wavenumber, phase, intensity, and visibility parameters via a nonlinear least-squares procedure that exploits the structure of the model. The pixel level parameters are then combined to obtain the required "global" moment and dispersion parameters. The process is applied to both simulated scenarios of astrometric observations and to data from the microarcsecond metrology testbed (MAM), an interferometer testbed that has played a prominent role in the development of this technology.     

Examining Implicit Discretization in Spectral Schemes

Two of the primary reasons rainbow color maps are considered ineffective trace back to the idea that they implicitly discretize encoded data into hue‐based bands, yet no research addresses what this discretization looks like or how consistent it is across individuals. This paper presents an exploratory study designed to empirically investigate the implicit discretization of common spectral schemes and explore whether the phenomenon can be modeled by variations in lightness, chroma, and hue. Our results suggest that three commonly used rainbow color maps are implicitly discretized with consistency across individuals. The results also indicate, however, that this implicit discretization varies across different datasets, in a way that suggests the visualization community's understanding of both rainbow color maps, and more generally effective color usage, remains incomplete.