We use large-eddy simulations to study the penetration of a buoyant plume carrying a passive tracer into a stably stratified layer with constant buoyancy frequency. Using a buoyancy-tracer volume distribution, we develop a method for objectively partitioning plume fluid in buoyancy-tracer space into three regions, each of which corresponds to a coherent region in physical space. Specifically, we identify a source region where undiluted plume fluid enters the stratified layer, a transport region where much of the transition from undiluted to mixed fluid occurs in the plume cap and an accumulation region corresponding to a radially spreading intrusion. This method enables quantification of different measures of turbulence and mixing within each of the three regions, including potential energy and turbulent kinetic energy dissipation rates, an activity parameter and the instantaneous mixing efficiency. We find that the most intense buoyancy gradients lie in a thin layer at the cap of the penetrating plume. This provides the primary stage of mixing between plume and environment and exhibits a mixing efficiency around 50 %. Newly generated mixtures of environmental and plume fluid join the intrusion and experience relatively weak turbulence and buoyancy gradients. As the intrusion spreads radially, environmental fluid surrounding the intrusion is mixed into the intrusion with moderate mixing efficiency. This dominates the volume of environmental fluid entrained into the region containing plume fluid. However, the ‘strongest’ entrainment, as measured by the specific entrainment rate, is largest in the plume cap, where the most buoyant environmental fluid is entrained.

Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.

Filamentary structures can form within the beam of protons accelerated during the interaction of an intense laser pulse with an ultrathin foil target. Such behaviour is shown to be dependent upon the formation time of quasi-static magnetic field structures throughout the target volume and the extent of the rear surface proton expansion over the same period. This is observed via both numerical and experimental investigations. By controlling the intensity profile of the laser drive, via the use of two temporally separated pulses, both the initial rear surface proton expansion and magnetic field formation time can be varied, resulting in modification to the degree of filamentary structure present within the laser-driven proton beam.

It has long been recognised that the Neolithic spread across Europe via two separate routes, one along the Mediterranean coasts, the other following the axis of the major rivers. But did these two streams have a common point of origin in south-west Asia, at least with regard to the principal plant and animals species that were involved? This study of barley DNA shows that the domesticated barley grown in Neolithic Europe falls into three separate types (groups A, B and C), each of which may have had a separate centre of origin in south-west Asia. Barley was relatively rarely cultivated by the early Linearbandkeramik farmers of Central and Northern Europe, but became more common during the fifth and fourth millennia BC. The analysis reported here indicates that a genetic variety of barley more suitable for northern growing conditions was introduced from south-west Asia at this period. It also suggests that the barley grown in south-eastern Europe at the very beginning of the Neolithic may have arrived there by different routes from two separate centres of domestication in south-west Asia. The multiple domestications that this pattern reveals imply that domestication may have been more a co-evolutionary process between plants and people than an intentional human action.

Aphidius ervi Hal. parasitised natural populations of Acyrthosiphon pisum (Harris), Sitobion avenae (F.) and Microlophium carnosum (Buckt.) in Britain but parasitised few examples of S. avenae placed on trap plants in winter wheat, nettle-grass edge areas or lucerne-wheat strip crops. In laboratory experiments, Aphidius ervi reared from Acyrthosiphon pisum did not parasitise M. carnosum, and significantly fewer mummies were formed on S. avenae than on A. pisum. After rearing Aphidius ervi for 4–5 generations on S. avenae, similar numbers of mummies were formed on both hosts. The switch of hosts from Acyrthosiphon pisum to S. avenae was associated with the loss of certain parasitoid esterase enzyme bands revealed following electrophoretic separation of parasitoid proteins. Slow adaptation to new aphid hosts by polyphagous parasitoids such as Aphidius ervi may reduce the usefulness of reservoirs as a source of beneficial species.

The present study compared performance of children with Attention-Deficit/Hyperactivity Disorder (ADHD) and high functioning autism (HFA) with that of controls on 4 tasks assessing 2 components of motor control: motor response inhibition and motor persistence. A total of 136 children (52 ADHD, 24 HFA, 60 controls) ages 7 to 13 years completed 2 measures of motor inhibition (Conflicting Motor Response and Contralateral Motor Response Tasks) and 2 measures of motor persistence (Lateral Gaze Fixation and NEPSY Statue). After controlling for age, IQ, gender, and basic motor speed, children with ADHD performed significantly more poorly than controls on the Conflicting Motor Response and Contralateral Motor Response Tasks, as well as on Statue. In contrast, children with HFA achieved lower scores than controls only on measures of motor persistence, with no concomitant impairment on either motor inhibition task. These results are consistent with prior research that has demonstrated relatively spared motor inhibition in autism. The findings highlight the utility of brief assessments of motor control in delineating the unique neurobehavioral phenotypes of ADHD and HFA. (JINS, 2006, 12, 622–631.)

The current status of SiC bulk growth is reviewed, while specific attention is given to the effect of defects in SiC substrates and epitaxial layers on device performance and yield. The progress in SiC wafer quality is reflected in the achievement of micropipe densities as low as 0.92 cm−2 for a 3-inch n-type 4H-SiC wafer, which provides the basis for a high yielding fabrication process of large area SiC power devices. Using a Murphy Probe Yield Analysis for the breakdown characteristics of 10 kV PiN diodes we have extracted an “effective” defect density for 4H-SiC material to be as low as 30 cm−2, providing valuable information to further isolate and address the specific material defects critical for device performance. We address the problematic degradation of the forward characteristics (Vf-drift) of bipolar SiC PiN diodes [CITE]. The underlying mechanism due to stacking fault formation in the epitaxial layers and possible effects of device processing are investigated. An improved device design is demonstrated, which effectively stabilizes this Vf-drift. We show the progression in the development of semi-insulating SiC grown by the sublimation technique from extrinsically doped material to high purity semi-insulating (HPSI) 4H-SiC bulk crystals of up to 100 mm diameter without resorting to the intentional introduction of elemental deep level dopants, such as vanadium. Uniform resistivities in 3-inch HPSI wafers greater than 3 × 1011 Ω-cm have been achieved. Secondary ion mass spectrometry, deep level transient spectroscopy and electron paramagnetic resonance data suggest that the semi-insulating behavior in HPSI material originates from deep levels associated with intrinsic point defects. MESFETs produced on HPSI wafers are free of backgating effects and have resulted in the best combination of power density and efficiency reported to date for SiC MESFETs of 5.2 W/mm and 63% power added efficiency (PAE) at 3.5 GHz.

Kabuki syndrome is a dysmorphogenic syndrome which has been reported in over 300 patients since it was first described in Japan in 1981. In addition to its cardinal features (typical facies, mild-to-moderate learning disability, short stature, skeletal anomalies, and dermatoglyphic abnormalities with persistent foetal fingerpads), neurological anomalies are frequently reported, including epilepsy in 8% of those with the syndrome. We present here a 22-year-old white female patient with refractory partial epilepsy, Kabuki syndrome, and bilateral perisylvian polymicrogyria on MRI: the first reported case of this association. The aetiology of the syndrome, including the diverse genetic changes recognized, is then discussed.

Fluorescein and the 1.4 nm Nanogold® gold cluster label may be incorporated into a single Fab’ immunoprobe by separate cross-linking reactions, to give a probe which labels antigenic sites in a single step for correlative fluorescence and electron microscope visualization. These probes show high labeling density, labeling a pre-mRNA splicing factor in the HeLa cell nucleus; Microtubules were also densely labeled using fluorescence, other optical modalities, and electron microscopy; in a parallel experiment, a 5 nm colloidal gold probe gave only occasional labeling. We now describe Fab’ and streptavidin probes containing both Nanogold® and the fluorescent cyanine dye, Cy3.

F(ab’)2 Goat anti-Mouse IgG and F(ab’)2 goat anti-rabbit IgG fragments were reductively cleaved to Fab’ fragments using dithiothreitol (DTT) or mercaptoethylamine hydrochloride (MEA), which selectively reduce the F(ab’)2 hinge disulfide bonds, with 5 mm EDTA to prevent reoxidation. Fab’ fragments were isolated by gel filtration (coarse gel: GH25, Amicon) then labeled with Monomaleimido- Nanogold® which reacts site-specifically with thiols. Streptavidin was labeled using Mono- Sulfo-NHS-Nanogold® at