Fourier Transform Spectroscopy of the submillimetre continuum emission from hot molecular cores

We have used a Fourier Transform Spectrometer on the James Clerk Maxwell Telescope to study the submillimetre continuum emission from dust in three hot molecular cores (HMC). The spectral index beta of the dust emission for these sources has been determined solely within the 30 GHz wide 350 GHz (850 micron) passband to an accuracy comparable to those determined through multi-wavelength observations. We find an average beta = 1.6, in agreement with spectral indices determined from previous submillimetre observations of these sources and with those determined for HMC in general. The largest single source of uncertainty in these results is the variability of the atmosphere at 350 GHz, and with better sky subtraction techniques we show that the dust spectral index can clearly be determined within one passband to high accuracy with a submillimetre FTS. Using an imaging FTS on SCUBA-2, the next generation wide-field submillimetre camera currently under development to replace SCUBA at the JCMT in 2006, we calculate that at 350 GHz it will be possible to determine beta to +/- 0.1 for sources as faint as 400 mJy/beam and to +/- 0.3 for sources as faint as 140 mJy/beam.Comment: 11 pages, 5 figures, accepted for publication in MNRA

Autumn Migration of Mississippi Flyway Mallards as Determined by Satellite Telemetry

We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n = 55), the average date when autumn migration began was October 23 (SE = 2.62 d; range = September 17–December 7). For those mallards that stopped for .1 d during migration, the average stopover length was 15.4 d (SE = 1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The total distance migrated per mallard averaged 1,407 km (SE = 89.55 km; range = 142–2,947 km). The average time spent on migration per individual between September 15 and December 15 was 27 d (SE = 2.88 d; range = 2–84 d). The state where most mallards were located on December 15 was Missouri (11) followed by Arkansas (8), while 5 mallards were still in Canada, and only 8 of 43 females and 0 of 10 males were present in Arkansas. The eastern Dakotas are a heavily utilized migration stopover for midcontinent mallards that may require more attention for migration habitat management. The reasons for so few mallards, especially male mallards, returning to Arkansas the following year deserves further research

Differential diagnosis of psycholinguistic disabilities of poor readers and some remedial procedures

The aims of the study were (a) to investigate the use of the Illinois Test of Psycholinguistic Abilities in the diagnosis of psycholinguistic deficit in first year junior schoolchildren having reading difficulties, and (b) to examine the effects of three educational programmes on the modification of the children's psycholinguistic abilities and reading attainments. From a population of over 1,000 children considered to be at educational risk because of poor reading attainment, a sample of 60 children was identified from four junior schools (i. e. 15 children in each school), selected at random from those schools having a high incidence of poor readers. The 60 children were tested on the ITPA, after which their scores were subjected to a profile analysis. This revealed marked deficits in the areas of Auditory Closure and Visual Sequential Memory. Three intervention programmes were constructed. The first was designed to ameliorate the specific disabilities in the two areas specified above. The second was a diffuse approach to language development which stressed the general training of oral language and verbal intelligence rather than specific training in psycholinguistic processes. A third group of children acting as a control group received a number programme. The children were retested on the ITPA and on various measures of reading attainment at the end of a twelve week treatment period and again ten months later. At the end of the experiment both groups receiving language training obtained higher composite psycholinguistic ages on the ITPA than the control group, but the pattern of psycholinguistic deficits was modified only in the group receiving specific training. Both language groups scored significantly higher than the control group on the tests of reading attainment. The results are interpreted as giving qualified support for the use of the ITPA as a test of differential diagnosis and in providing suggestions for remedial programmes

A Digital Class-D Single-Sideband Transmitter

This is the final version of the article. Available from BCRA via the DOI in this record.Graham Naylor has discovered a novel method of SSB synthesis that makes use of digital techniques, for which he has received the 2006 CREG award. Together with David Gibson, he describes how it works

Gravitino fields in Schwarzschild black hole spacetimes

The analysis of gravitino fields in curved spacetimes is usually carried out using the Newman-Penrose formalism. In this paper we consider a more direct approach with eigenspinor-vectors on spheres, to separate out the angular parts of the fields in a Schwarzschild background. The radial equations of the corresponding gauge invariant variable obtained are shown to be the same as in the Newman-Penrose formalism. These equations are then applied to the evaluation of the quasinormal mode frequencies, as well as the absorption probabilities of the gravitino field scattering in this background.Comment: 21 pages, 2 figures. arXiv admin note: text overlap with arXiv:1006.3327 by other author

Dynamic optimal taxation with human capital.

This paper revisits the dynamic optimal taxation results of Jones, Manuelli, and Rossi (1993, 1997). They use a growth model with human capital and find that optimal taxes on both capital income and labor income converge to zero in steady state. For one of the models under consideration, I show that the representative household's problem does not have an interior solution. This raises concerns since these corners are inconsistent with aggregate data. Interiority is restored if preferences are modified so that human capital augments the value of leisure time. With this change, the optimal tax problem is analyzed and, reassuringly, the Jones, Manuelli, and Rossi results are confirmed: neither capital income nor labor income should be taxed in steady state

Constructing apprenticeships by transforming through sharing

As a result of a general dissatisfaction among construction industry employers with the current apprenticeship training in the UK a local training group, in collaboration with a further education provider and the Sector Skills Council for construction, developed an innovative training scheme. The claim of the Shared Apprenticeship scheme was to transform the learning experiences of construction apprentices by accentuating their craft skills development, broadening their vocational knowledge and sharing their on-site experiences through a consortium of employers. Whilst this three year, partly European funded, project is operated by the local construction training group it is managed by ConstructionSkills with the local FE college providing the underpinning skills development and extended knowledge. The project is noteworthy not least because it involves significant public funds and numbers of apprentices but it also attracts global attention from decision formers delivering similar programmes. This study explores the reasons for the Shared Apprenticeship project and considers similar schemes through literature review and interviews with stakeholders. Not everyone views this project as innovative or shares the optimisms anticipated by the creators of the scheme and in this context the study especially scrutinises expectations and limitations