Spectral ageing: a new age perspective

We present an up-to-date critique of the physical basis for the spectral ageing method. We find that the number of cases where this method may be meaningfully applied to deduce the ages of classical double radio sources is small indeed. This critique is much more than merely a re-expression of anxieties about the calibration of spectral ageing (which have been articulated by others in the past).Comment: 9 pages, 3 figures, published in `Particles & Fields in Radio Galaxies', PASP, eds RA Laing & KM Blundel

Interaction of Stern layer and domain structure on photochemistry of lead-zirconate-titanate.

Perovskite ferroelectric materials such as PZT have long been known to have wideband semiconducting properties. It has also been found that they have interesting spatially controllable surface photochemical effects that are not seen in 'normal' semiconductors. This has led to their being studied as possible tools in areas such as metal salt reduction and oxidation for nanoparticle growth. This paper discusses the effects of incident photon energy on the reduction of Ag0 onto PZT(30/70) surfaces with particular emphasis on the part played by energy band bending and the Stern layer. It was found that for increasing photon energy between 4.4 and 5.0 eV both the [1 1 1] and the [1 0 0] orientations of PZT followed a similar trend in that the average Ag0 cluster cross-sectional area increased by a ratio of ca 1.6 to 1. This increase was put down to the higher energy photons exciting more electrons from deeper in the density of states for the material allowing a greater reduction rate of Ag+ at the surface

Relationships between Time Management, Control, Work–family Conflict, and Strain

This article incorporates recent research regarding time management into a model of work–family conflict. The authors hypothesized that 3 types of time management behavior would have both direct and indirect (through perceived control of time) relationships, with work interfering with family and family interfering with work. It was also hypothesized that both of these types of work-family conflict would be related to the strain outcomes of job dissatisfaction and health complaints. This model was tested with a sample of 522 workers. In general, the hypothesized relationships were supported

Best Practices of Honor Societies

Academic honor societies are widely available within university communities. These student organizations can fill valuable roles within engineering departments. The inception of engineering-related honor societies followed the establishment of engineering education within American universities. Honor societies with their student focus grew as complementary organizations to the professional societies for engineering disciplines. The national or international structure of honor societies generally provides considerable resources for professional education, leadership training, and service activity. For departments, an honor society chapter can provide engagement with students, alumni, community, etc. However, the existence of an honor society chapter at an institution does not necessarily mean that the chapter is effectively serving the host department(s) and its engineering students. This paper describes commonalities among engineering honor societies, the possible roles of an honor society within an engineering department, and some best practices for effective honor society chapters. Specific examples from the operation of IEEE-Eta Kappa Nu (IEEE-HKN), the honor society of the Institute of Electrical and Electronics Engineers (IEEE), are given.Cockrell School of Engineerin

Effect of Aquathol K Treatments on Activity Patterns of Largemouth Bass in Two Coves of Lake Seminole, Georgia

Thirty largemouth bass ( Micropterus salmoide s Lacepde) were implanted with radio tags in late October 2003 in two coves of Lake Seminole, Georgia, and tracked over a 24-hour period about every 10 days to determine their response to herbicide application. After five weeks of tracking, hydrilla ( Hydrilla verticillata Royle) in each cove was treated in early December 2003 with dipotassium salt of endothall (Aquathol K; 7-oxabicyclo [2.2.1] heptane-2,3-dicarboxylic acid) at a rate of 3.5 ppm. Largemouth bass were tracked during application and tracking continued for three months post treatment to assess effects of herbicide treatment on activity patterns. The treatment in Desser Cove successfully reduced hydrilla in approximately half the cove. However, the treatment in Peacock Lake completely eliminated all submersed aquatic vegetation (SAV) by April 2004. Movement and activity centers remained similar between treatment periods in Desser Cove, but increased after treatment in Peacock Lake. Depth occupied by telemetered fish decreased after Aquathol K treatment in both coves. In general, behavior of largemouth bass did not change appreciably during treatment, and only minor changes were observed in the posttreatment period in Peacock Lake, where all SAV was eliminated. Fish showed little attraction to or movement away from treatment areas, and fish migration from either cove was nil after treatment. Application of Aquathol K and subsequent reduction of SAV had little effect on largemouth bass behavior or movement. (PDF has 8 pages.

A versatile all-channel stimulator for electrode arrays, with real-time control

Over the last few decades, technology to record through ever increasing numbers of electrodes has become available to electrophysiologists. For the study of distributed neural processing, however, the ability to stimulate through equal numbers of electrodes, and thus to attain bidirectional communication, is of paramount importance. Here, we present a stimulation system for multi-electrode arrays which interfaces with existing commercial recording hardware, and allows stimulation through any electrode in the array, with rapid switching between channels. The system is controlled through real-time Linux, making it extremely flexible: stimulation sequences can be constructed on-the-fly, and arbitrary stimulus waveforms can be used if desired. A key feature of this design is that it can be readily and inexpensively reproduced in other labs, since it interfaces to standard PC parallel ports and uses only off-the-shelf components. Moreover, adaptation for use with in vivo multi-electrode probes would be straightforward. In combination with our freely available data-acquisition software, MeaBench, this system can provide feedback stimulation in response to recorded action potentials within 15 ms