Experimentally estimated dead space for GaAs and InP based planar Gunn diodes

The authors would like to thank the staff of the James Watt Nanofabrication Centre at the University of Glasgow for help in fabricating the devices which is reported in this paper. ‘Part of this work was supported by ESPRC through EP/H011862/ 1, and EP/H012966/1.Peer reviewedPublisher PD

A bibliography of published information relevant to fire toxicity

A bibliography containing 883 references in the field of fire toxicity is presented to assist in literature searches to help reduce human fire hazards

Impact ionisation electroluminescence in planar GaAs-based heterostructure Gunn diodes:Spatial distribution and impact of doping nonuniformities

When biased in the negative differential resistance regime, electroluminescence (EL) is emitted from planar GaAs heterostructure Gunn diodes. This EL is due to the recombination of electrons in the device channel with holes that are generated by impact ionisation when the Gunn domains reach the anode edge. The EL forms non-uniform patterns whose intensity shows short-range intensity variations in the direction parallel to the contacts and decreases along the device channel towards the cathode. This paper employs Monte Carlo models, in conjunction with the experimental data, to analyse these non-uniform EL patterns and to study the carrier dynamics responsible for them. It is found that the short-range lateral (i.e., parallel to the device contacts) EL patterns are probably due to non-uniformities in the doping of the anode contact, illustrating the usefulness of EL analysis on the detection of such inhomogeneities. The overall decreasing EL intensity towards the anode is also discussed in terms of the interaction of holes with the time-dependent electric field due to the transit of the Gunn domains. Due to their lower relative mobility and the low electric field outside of the Gunn domain, freshly generated holes remain close to the anode until the arrival of a new domain accelerates them towards the cathode. When the average over the transit of several Gunn domains is considered, this results in a higher hole density, and hence a higher EL intensity, next to the anode

Paraoxonase gene polymorphisms and haplotype analysis in a stroke population

Peer reviewedPublisher PD

Boosting clinical performance: The impact of enhanced final year placements.

BACKGROUND: This study follows on from a study that investigated how to develop effective final year medical student assistantship placements, using multidisciplinary clinical teams in planning and delivery. AIMS: This study assessed the effects on objective structured clinical examination (OSCE) performance of the in-course enhanced "super-assistantship" placement introduced to a randomly selected sample of 2013-14 final year medical students at Leeds medical school. METHODS: Quantitative data analysis was used to compare the global grades of OSCE stations between students who undertook this placement against those who did not. RESULTS: There was a small overall improvement in the "super-assistantship" student scores across the whole assessment (effect size = 0.085). "Pre-op Capacity", "Admissions Prescribing" and "Hip Pain" stations had small-medium effect sizes (0.226, 0.215, and 0.214) in favor of the intervention group. Other stations had small effect sizes (0.107-0.191), mostly in favor of the intervention group. CONCLUSIONS: The "super-assistantship" experience characterized by increasing student responsibility on placement can help to improve competence and confidence in clinical decision-making "in a simulated environment". The clinical environment and multidisciplinary team must be ready and supported to provide these opportunities effectively. Further in-course opportunities for increasing final year student responsibility should be developed

A contribution to the biology of warthog (Phacochoerus africanus, Gmelin) in the Sengwa region of Rhodesia

To the AmaZulu a warthog is "inhlovudawana" or "little elephant"; to arrogant hunters it is the "poor man's rhinoceros"; to some writers of encyclopaediae it is a "grotesque and hideous beast"; to stockmen it has long been a carrier of diseases. Injury was added to insult with the discovery that the blood of these self-assured, often comical and certainly engaging animals supports the greater proportion of tsetse flies in the African savannas. Their significance as the primary hosts of Glossina morsitans Westw., the vectors of tryanosomiasis, justified an extended field study of warthog biology. This thesis reports four years of field work on warthogs, together with complementary observations of hand-reared warthogs (and their offspring) which roamed freely in the vicinity of the remote field station on which I live. The Sengwa Research Project, of which this study forms a part, was initiated in 1965 to study relationships between game animals and tsetse flies. One of the main problems investigated in the Sengwa Project is that of "host encounter" (Glasgow, 1961, Bursell, 1970) and how the distribution, abundance and behaviour of game animals may affect their availability to hungry tsetse flies. I have, accordingly, been concerned with discovering how warthog are dispersed in the Sengwa area and have attempted to gain some understanding of the factors, both environmental and social, which may affect or govern their dispersion and possibly population number. Intro. p. 1

Mitigation of Moral Hazard and Adverse Selection in Venture Capital Financing: The Influence of the Country’s Institutional Setting

A venture capitalist (VC) needs to trade off benefits and costs when attempting to mitigate agency problems in their investor-investee relationship. We argue that signals of ventures complement the VC’s capacity to screen and conduct a due diligence during the pre-investment phase, but its attractiveness may diminish in institutional settings supporting greater transparency. Similarly, whereas a VC may opt for contractual covenants to curb potential opportunism by ventures in the post-investment phase, this may only be effective in settings supportive of shareholder rights enforcement. Using an international sample of VC contracts, our study finds broad support for these conjectures. It delineates theoretical and practical implications for how investors can best deploy their capital in different institutional settings whilst nurturing their relationships with entrepreneurs

Micro-cooler Enhancements by Barrier Interface Analysis

Peer reviewedPublisher PD

Spectral Modeling of SNe Ia Near Maximum Light: Probing the Characteristics of Hydro Models

We have performed detailed NLTE spectral synthesis modeling of 2 types of 1-D hydro models: the very highly parameterized deflagration model W7, and two delayed detonation models. We find that overall both models do about equally well at fitting well observed SNe Ia near to maximum light. However, the Si II 6150 feature of W7 is systematically too fast, whereas for the delayed detonation models it is also somewhat too fast, but significantly better than that of W7. We find that a parameterized mixed model does the best job of reproducing the Si II 6150 line near maximum light and we study the differences in the models that lead to better fits to normal SNe Ia. We discuss what is required of a hydro model to fit the spectra of observed SNe Ia near maximum light.Comment: 29 pages, 14 figures, ApJ, in pres