Pulsed force sequences for fast phase-insensitive quantum gates in trapped ions

We show how to create quantum gates of arbitrary speed between trapped ions, using a laser walking wave, with complete insensitivity to drift of the optical phase, and requiring cooling only to the Lamb-Dicke regime. We present pulse sequences that satisfy the requirements and are easy to produce in the laboratory.Comment: 11 pages, 3 figure

A review of knowledge: inter-row hoeing & its associated agronomy in organic cereal & pulse crops

The aim of this project was to establish the “state of the art” for inter-row hoeing and its associated agronomic practices in organic cereal and pulse crops. To achieve this a detailed review of literature was undertaken. • To facilitate inter-row cultivation in cereal and pulse crops, some adjustment of row spacing may be required. For cereals, drilling crops in 25 cm rows can reduce yield compared with normal drilling practice, primarily due to greater intra-specific competition amongst the crop (i.e. competition between crop plants). • The yield penalty resulting from widely spaced crop rows can be minimised using a number of approaches, depending on the drill: 1. Reducing the seed rate in widely spaced crop rows can help to minimise excessive intra-specific competition. 2. Band sowing the crop in wide rows can also help to minimise intra-specific competition as the seed is distributed over a greater area. 3. Using a twin-row arrangement can completely overcome the yield penalty. • The recommended row spacing for peas (up to 20 cm) and beans (up to 35 cm) does not require any further adjustment for inter-row hoeing. • Recent developments in automated guidance of inter-row hoeing equipment mean that weeding operations can now be conducted a much higher speeds (10 km h-1). This has highlighted the limitations of some of the cultivators currently used (e.g. ‘A’ blades), as excessive soil throw can occur at this high speed. Rolling cultivators may prove to be the most suitable at high forward speeds. For manually guided hoes working at slower speeds (5 km h-1), ‘A’ and ‘L’ blades offer an effective low cost solution. • In terms of the timing of inter-row hoeing, it is suggested that weeding operations should be conducted at an early stage in the growing season, as the weeds that emerge with or shortly after the crop are the ones that pose the most significant threat for crop yield. Weeding on two occasions can provide better levels of weed control than weeding once, but weeding more frequently offered little additional benefit. Reductions of weed biomass of up to 99 % have been reported as a result of inter-row hoeing, although this has not always resulted in a positive crop yield response. This is probably due to crop damage resulting from inaccurate hoeing, a problem that can be overcome with automated guidance. • There is some evidence to suggest that mechanical weeding operations can mineralise soil bound nitrogen. • The impact of inter-row hoeing on ground nesting birds is uncertain. Early indications suggest that skylarks prefer to nest directly adjacent to or in the crop row rather than between rows. The information contained within this review should enable farmers to make best use of inter-row hoeing in their arable crops. There are a number of areas that require further research and development: • The interaction of seed rate and row spacing needs to be confirmed in organic systems. • Relatively little is known about the mechanisms of weed kill and the detailed interaction between the cultivator blade, the weed and the soil. This is particularly important with the new automated guidance equipment that allows weeding at high forward speeds. • The timing and frequency of inter-row hoeing has received very little attention. The optimum weed control timings are based on small-plot crop:weed competition studies and need to be verified under field scale management with inter-row hoeing equipment. • Finally, the impact of inter-row hoeing and widely spaced crop rows on ground-nesting birds has not been looked at directly, but is of importance. Please see the main report for a more detailed summary before the full text

Energy distribution of charged dilaton black holes

Chamorro and Virbhadra studied, using the energy-momentum complex of Einstein, the energy distribution associated with static spherically symmetric charged dilaton black holes for an arbitrary value of the coupling parameter $\gamma$ which controls the strength of the dilaton to the Maxwell field. We study the same in Tolman's prescription and get the same result as obtained by Chamorro and Virbhadra. The energy distribution of charged dilaton black holes depends on the value of $\gamma$ and the total energy is independent of this parameter.Comment: 8 pages, RevTex, no figure

An ion trap built with photonic crystal fibre technology

We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787(24) quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 um and 10 um.Comment: 6 pages, 4 figure

Denying humanness to victims: How gang members justify violent behavior

The high prevalence of violent offending amongst gang-involved youth has been established in the literature. Yet the underlying psychological mechanisms that enable youth to engage in such acts of violence remain unclear. 189 young people were recruited from areas in London, UK, known for their gang activity. We found that gang members, in comparison to non-gang youth, described the groups they belong to as having recognized leaders, specific rules and codes, initiation rituals, and special clothing. Gang members were also more likely than non-gang youth to engage in violent behavior and endorse moral disengagement strategies (i.e., moral justification, euphemistic language, advantageous comparison, displacement of responsibility, attribution of blame, and dehumanization). Finally, we found that dehumanizing victims partially mediated the relationship between gang membership and violent behavior. These findings highlight the effects of groups at the individual level and an underlying psychological mechanism that explains, in part, how gang members engage in violence

A comparison of intermediate and long-acting insulins in people with type 2 diabetes starting insulin: an observational database study

AimsInsulin is normally added to oral glucose-lowering drugs in people with type 2 diabetes when glycaemic control becomes suboptimal. We evaluated outcomes in people starting insulin therapy with neutral protamine Hagedorn (NPH), detemir, glargine or premixed insulins.MethodsInsulin-naïve people with type 2 diabetes (n = 8009), ≥ 35 years old, HbA(1c) ≥ 6.5% and begun on NPH (n = 1463), detemir (n = 357), glargine (n = 2197) or premix (n = 3992), were identified from a UK database of primary care records (The Health Improvement Network). Unadjusted and multivariate-adjusted analyses were conducted, with persistence of insulin therapy assessed by survival analysis.ResultsIn the study population (n = 4337), baseline HbA(1c) was 9.5 ± 1.6%, falling to 8.4 ± 1.5% over 12 months (change -1.1 ± 1.8%, p Discussion and conclusionIn routine clinical practice, people with type 2 diabetes commenced on NPH experienced a modest disadvantage in glycaemic control after 12 months compared with other insulins. When comparing the insulins, glargine achieved best HbA(1c) reduction, while premix showed greatest weight gain and the highest dose requirement, but had the best persistence of therapy.J. Gordon, R. D. Pockett, A. P. Tetlow, P. McEwan, P. D. Hom