Miniature Optical Wide-Angle-Lens Startracker (Mini-OWLS)

This paper provides a brief overview of the design considerations and the current status of the Miniature Optical Wide-Angle Lens Startracker Program. Mini-OWLS offers a revolutionary alternative to the conventional startracker. It is a small, lightweight, low cost, high performance startracker that can be used in a variety of applications including calibration and alignment of Inertial Measurement Units (IMU's) Mini-OWLS makes use of a strap down design incorporating Holographic Optical Elements (HOES) in place of conventional optics. HOES can be multiplexed so that the same aperture can be used for multiple separate optical paths looking in several directions simultaneously without startracker rotation. Additionally, separate Schmidt corrector plates are not required to compensate for spherical aberration. The optical assembly, or what would normally be considered as the telescope, is less than 20 cc in volume, weighs less than 55 grams, and contains the equivalent of three individual telescopes. Each one has a 4 deg Field of View (FOV) with a field of regard of 48 square degrees. Mini-OWLS has a bandwidth of approximately 300 nm in or near the visible wavelength. The projected resolution of the startracker is 5 to 10 arcseconds, depending on the centroiding algorithm used. The Mini-OWLS program was initiated last year and represents a miniaturized version of a similar design for aeronautical applications. The contract is managed by Wright Laboratory, Air Force Systems Command, Wright-Patterson AFB, Ohio, with funding from the Strategic Defense Initiative Organization through Eglin AFB. The initial phase of the program is to build and test a development unit. The second phase is to integrate the startracker with the Charles Stark Draper Laboratory Micromechanical Inertial Guidance System (MIGS) and the Signal Processing Packaging Design (SPPD) being developed by Texas Instruments. The preliminary design review was conducted in November 1991. Three-axes prototype telescope assemblies have been built and design evaluation tests initiated

Rapidity Gaps Between Jets

An excess of events with a rapidity gap between jets, over what would be expected from non-diffractive processes, has been observed at HERA. A process based on a perturbative QCD calculation of colour singlet exchange has been added to HERWIG. With this addition, HERWIG is able to describe the number of events with a gap between jets over the number without a gap. This gap fraction is predicted to rise at large rapidity intervals between jets which would only be visible if the detector coverage were increased.Comment: 5 pages including 3 figures. To appear in the conference proceedings of the Workshop "Future Physics at HERA

EMOTION REGULATION MEDIATES THE RELATIONSHIP BETWEEN ADHD AND DEPRESSIVE SYMPTOMS IN YOUTH

A significant body of longitudinal research suggests increased rates of mood disorders as well as depressive symptoms in youth diagnosed with attention deficit/ hyperactivity disorder (ADHD) in contrast to non-ADHD comparison youth. Furthermore, individuals with co-occurring ADHD and mood disorders experience more serious impairments and worse outcomes than those with either disorder alone. However, few studies have examined the underlying mechanisms which may better elucidate the relationship between ADHD and depression in youth. The present study examined emotion regulation as a mediator in the relationship between ADHD and depressive symptoms in youth. Moreover, effortful control was examined as a mediator in the relationship between ADHD and emotion regulation. Participants included 69 youth between the ages of 10 and 14 with (n = 37) and without (n = 32) DSM-IV ADHD. Parent and youth ratings of depressive symptoms and emotion regulation were collected, and youth completed computerized measures of effortful control. Results demonstrated significant differences between youth with and without ADHD on depressive symptoms and emotion regulation ability, but not effortful control. Furthermore, emotion regulation fully mediated the relationship between ADHD and depressive symptoms. Clinical implications and limitations are discussed

Solid state image sensor research Final technical report

Fifty-element linear arrays of InAs photodiode

Inducing metamorphosis in the irukandji jellyfish Carukia barnesi

Here we utilize chemical ecology as a tool to manipulate the biological system of a small, but highly venomous to humans, cubozoan jellyfish, Carukia barnesi. We trialled a range of chemical reagents including indole compounds, 9-cis-retinoic acid and lugols solution to induce metamorphosis between the polyp and medusa life stages. An optimum method was determined resulting in a 90% metamorphosis rate to healthy medusa by exposing the polyps to 1 μM of 5-methoxy-2-methylindole for 24 h. Of note is that chemical exposure time significantly impacts health and metamorphosis rates in this species. We also present a theoretical mechanism for the chemical/biological interactions occurring during metamorphosis. This is a significant methodological advancement which now enables rearing of this animal en mass in aquaria—a world first for this species—which will subsequently supply and facilitate venom research into this understudied jellyfish

Global Diffusion of the Internet VI: The Internet in Togo

The Global Diffusion of the Internet (GDI) framework is used to examine Internet diffusion in Togo along six dimensions: Pervasiveness, Geographical Dispersion, Sectoral Absorption, Connectivity Infrastructure, Organizational Infrastructure, and Sophistication of Use. The Internet in Togo originated in the private sector in 1996. In the years that followed, the Togolese Internet grew at a slower rate than the Internet in many other countries over the same period of time. After examining how each dimension evolved, this study concludes, amongst many suggestions, that the Togolese government should encourage more telecommunication infrastructure development by allowing private companies to utilize Togo Telecom\u27s network

Introducing the Global Diffusion of the Internet Series

While there is no shortage of commentary on the nature and impact of the Internet, a deep understanding of this phenomenon and its diffusion must go beyond the collection of factoids, such as the number of hosts and users, to capture the context within which the Internet evolves. This paper introduces a CAIS series entitled The Global Diffusion of the Internet, which seeks to promote research efforts that contribute to our understanding of the diffusion of the Internet throughout the world, that create and apply analytic frameworks that permit comparative analyses, and that capture the rather perishable history of the Internet as it unfolds. Contributions by scholars from parts of the world that are under-represented among the AIS membership are particularly encouraged