ULTRACAM photometry of the eclipsing cataclysmic variables GY Cnc, IR Com and HT Cas

We present high-speed, three-colour photometry of the eclipsing cataclysmic variables GY Cnc, IR Com and HT Cas. We find that the sharp eclipses in GY Cnc and IR Com are due to eclipses of the white dwarf. There is some evidence for a bright-spot on the edge of the accretion disc in GY Cnc, but not in IR Com. Eclipse mapping of HT Cas is presented which shows changes in the structure of the quiescent accretion disc. Observations in 2002 show the accretion disc to be invisible except for the presence of a bright-spot at the disc edge. 2003 observations, however, clearly show a bright inner disc and the bright-spot to be much fainter than in 2002. Although no outburst was associated with either set of quiescent observations, the system was similar to 0.6 mJy brighter in 2003, mainly due to the enhanced emission from the inner disc. We propose that these changes are due to variations in the mass-transfer rate from the secondary star and through the disc. The disc colours indicate that it is optically thin in both its inner and outer regions. We estimate the white dwarf temperature of HT Cas to be 15 000 +/- 1000 K in 2002 and 14 000 +/- 1000 K in 2003.

Biological influence on the morphology and micromorphology of selected Podzols (Spodosols) and Cambisols (Inceptisols) from the Eastern United States and Northeast Scotland

Biological activities greatly influence the formation of many soils, especially forest soils under cool humid climates. The objective of this study was to investigate the effects of vegetation and soil biota on the formation of selected soils. Field morphology, micromorphology, and carbon and organic matter analysis were determined on six Podzols (Spodosols) and two Cambisols (Inceptisols) from the eastern United States and north-east Scotland. Humification of plant material by soil fauna and fungi occurs in all organic horizons. Thick organic coatings are observed on soil peds and rock fragments from the E1 to the Bs horizon in a Haplic Podzol from Clingmans Dome Mt., TN. Thin sections reveal large accumulations of root material in different stages of decomposition in the spodic horizons of a Haplic Podzol from Whiteface Mt., NY. Organic carbon ranges from 5.4 to 8.5% in the spodic B horizons of the Whiteface Mt. Podzol. Earthworms and enchytraeids have a great effect on the structure of the surface and subsurface horizons in the Dystric Cambisols from Huntly and Clashindarroch Forests, Scotland and a Cambic Podzol from the Corrie Burn Basin, Scotland. Podzols from Speymouth Forest, Scotland (Gleyic Podzol), Cling-mans Dome Mt., and Whiteface Mt. have thick organic horizons. The Podzols from the Flatwoods in Georgia, the Pine Barrens in New Jersey, the Corrie Burn Basin, and the Cambisol from Huntly Forest have only A horizons at the surface. The Clashindarroch Forest soil has a very thin organic horizon. Warm and humid climates and sandy parent material are responsible for thick E horizons and lack of thick organic horizons in the Flatwoods (Carbic Podzol) and Pine Barrens (Ferric Podzol) soils. Earthworms and enchytraeids thrive in the Corrie Burn Basin and Huntly Forest soils due to the vegetation and the highly weathered basic parent material. The site at Clashindarroch once carried oak, and then birch forest, both of which produce a mild litter and also encourage earthworm and enchytraeids. This fauna is responsible for much mixing of the topsoil. The present conifer vegetation will eventually produce a deep litter and cause podzolization.

Gas-Phase Formation of Doubly-Deuterated Species

We present the first results from a time-dependent chemical model to include a gas-phase reaction scheme for producing doubly-deuterated species. Under normal conditions the formation of these species is inefficient. However, when the effects of the freeze out of gas phase species onto grains is included in the chemistry we find that the fractionation of both singly and doubly deuterated species is enhanced. We compare the predictions from our models with recent observations of deuterated molecules in L134N and find that, contrary to previous expectations, we can reproduce the observed levels of fractionation without recourse to an active grain-surface chemistry.

A Profile of Adolescent Cocaine Use in Northern Ireland.

Background: The image of cocaine as a 'party' drug used by more affluent members of society has begun to change as the levels of use of the drug rise amongst school aged young people. Methods: Cocaine use patterns amongst young people aged 13-16 years who were participating in the Belfast Youth Development Study, a longitudinal study of adolescent drug use was explored. Data was collected through an annual datasweep in participating schools. This paper includes data collected in years 3, 4 and 5 of the study. Results: The results show higher levels of cocaine use amongst this age group than reported in much of the existing harm reduction literature. Lifetime use was 3.8% at age 13-14 years, rising to 7.5% at 15-16 years. The profile indicated that adolescent cocaine users were more likely to be female, live in disrupted families and experience social deprivation which is similar to existing adolescent drug use profiles. There was also some evidence of experimental cocaine use amongst the sample. Conclusions: These findings provide further evidence for the development of age appropriate school focused harm reduction initiatives and continued monitoring of contemporary trends of use of cocaine amongst school aged young people.

Upregulation of Oxidative Stress Markers in Human Microvascular Endothelial Cells by Complexes of Serum Albumin and Digestion Products of Glycated Casein

The extent of absorption of dietary advanced glycation end products (AGEs) is not fully known. The possible physiological impact of these absorbed components on inflammatory processes has been studied little and was the aim of this investigation. Aqueous solutions of bovine casein and glucose were heated at 95 degrees C for 5 h to give AGE-casein (AGE-Cas). Simulated stomach and small intestine digestion of AGE-Cas and dialysis (molecular mass cutoff of membrane = 1 kDa) resulted in a low molecular mass (LMM) fraction of digestion products, which was used to prepare bovine serum albumin (BSA)-LMM-AGE-Cas complexes. Stimulation of human microvascular endothelial cells with BSA-LMM-AGE-Cas complexes significantly increased mRNA expression of the receptor of AGE (RAGE), galectin-3 (AGE-113), tumor necrosis factor alpha, and a marker of the mitogen-activated protein kinase pathway (MAPK-1), as well as p65NF-kappa B activation. Cells treated with LMM digestion products of AGE-Cas significantly increased AGE-R3 mRNA expression. Intracellular reactive oxygen species production increased significantly in cells challenged with BSA-LMM-AGE-Cas and LMM-AGE-Cas. In conclusion, in an in vitro cell system, digested dietary AGEs complexed with serum albumin play a role in the regulation of RAGE and down-stream inflammatory pathways. AGE-R3 may protect against these effects.

Effects of breed and production system on lameness parameters in dairy cattle

The aim of the present study was to assess the effects of Holstein-Friesian (HF) and Norwegian (N) dairy cattle genotypes on lameness parameters in dairy cattle within different production systems over the first 2 lactations. Following calving, HF (n = 39) and N (n = 45) heifers were allocated to 1 of 3 systems of production (high level of concentrate, low level of concentrate, and grass-based). High-and low-concentrate animals were continuously housed indoors on a rotational system so that they spent similar amounts of time on slatted and solid concrete floors. Animals on the grass treatment grazed from spring to autumn in both years of the study, so that most animals on this treatment grazed from around peak to late lactation. Claw health was recorded in both hind claws of each animal at 4 observation periods during each lactation as follows: 1) -8 to 70 d postcalving, 2) 71 to 150 d postcalving, 3) 151 to 225 d postcalving, and 4) 226 to 364 d postcalving. Sole lesions, heel erosion, axial wall deviation, sole length of the right lateral hind claw (claw length), right heel width, and right lateral hind heel height were recorded as well as the presence of digital dermatitis. The N cows had lower (better) white line and total lesion scores than HF cows. Cows on the high-and low-concentrate treatments had better sole and total lesion scores than cows on the grass treatment. The HF cows had better locomotion scores than N cows. Breed and production system differences were observed with respect to claw conformation, including claw length, heel width, and heel height. Digital dermatitis was associated with worse sole lesion scores and interacted with production system to influence white line lesion scores and maximum heel erosion scores. This study shows that genetic, environmental, and infectious factors are associated with hoof pathologies in dairy cows.

Reconfigurable system-on-a-chip motion estimation architecture for multi-standard video coding

A new domain-specific, reconfigurable system-on-a-chip (SoC) architecture is proposed for video motion estimation. This has been designed to cover most of the common block-based video coding standards, including MPEG-2, MPEG-4, H.264, WMV-9 and AVS. The architecture exhibits simple control, high throughput and relatively low hardware cost when compared with existing circuits. It can also easily handle flexible search ranges without any increase in silicon area and can be configured prior to the start of the motion estimation process for a specific standard. The computational rates achieved make the circuit suitable for high-end video processing applications, such as HDTV. Silicon design studies indicate that circuits based on this approach incur only a relatively small penalty in terms of power dissipation and silicon area when compared with implementations for specific standards. Indeed, the cost/performance achieved exceeds that of existing but specific solutions and greatly exceeds that of general purpose field programmable gate array (FPGA) designs.

Perception of emotion: towards a realistic understanding of the task

A decade ago, perceiving emotion was generally equated with taking a sample (a still photograph or a few seconds of speech) that unquestionably signified an archetypal emotional state, and attaching the appropriate label. Computational research has shifted that paradigm in multiple ways. Concern with realism is key. Emotion generally colours ongoing action and interaction: describing that colouring is a different problem from categorizing brief episodes of relatively pure emotion. Multiple challenges flow from that. Describing emotional colouring is a challenge in itself. One approach is to use everyday categories describing states that are partly emotional and partly cognitive. Another approach is to use dimensions. Both approaches need ways to deal with gradual changes over time and mixed emotions. Attaching target descriptions to a sample poses problems of both procedure and validation. Cues are likely to be distributed both in time and across modalities, and key decisions may depend heavily on context. The usefulness of acted data is limited because it tends not to reproduce these features. By engaging with these challenging issues, research is not only achieving impressive results, but also offering a much deeper understanding of the problem.