Ion distribution and temperature in the topside ionosphere obtained from the Alouette satellite

Ion distribution and temperature of topside ionosphere from electron density measurements by Alouette satellit

A comparison of ultrasonic and mechanical stadiometry

AIM: To compare an ultrasonic height measuring device (Gulliver) with mechanical stadiometry and the classical "book and tape measure" method. METHODS: Blinded duplicate measurements of height were made on each of 14 children by a pair of observers using a stadiometer (H) and Gulliver (G). Height was measured on a further 18 children by parents and an auxologist using Gulliver and the book and tape method (TM), and the results were compared with those obtained with a single stadiometry measurement. Finally, measurement of a rigid metal box was made on 10 occasions by the three methods. RESULTS: In the group of 14 children, the mean difference (range) in height (H minus G) was +2.8 cm (+0.5 to +4.55 cm), with H giving a systematically higher value in 276 of 280 individual measurements. In the group of 18 children, height by H was greater than by G or TM in 47 of 52 individual measurements. The mean (SD) height of the box by H (61.60 (0.07) cm) was greater than by G (60.96 (0.15) cm; p 0.05). G and TM produced three times less reliable estimations of height than H, but with a large difference in cost, and there was evidence of systematic underrecording of height by 0.5 cm with G. CONCLUSIONS: Stadiometry is precise and reproducible, and can detect true changes in height over one month periods in mid-childhood, and should remain the standard way of observing growth. The book and tape method can produce clinically acceptable quarterly estimations of height that can be performed in the home

Influences of lateral preference and personality on behaviour towards a manual sorting task

Differences in task behaviour between left- and right-handers and left- and right-eared individuals have been reported (e.g. Jackson, 2008 and Wright et al., 2004) with left-handers taking longer to begin a task and right-eared individuals having a more disinhibited approach. Personality measurements are also important when examining approach behaviour. Jackson (2008) reported that those with higher neuroticism levels and a right-ear preference react faster to tasks. The current study investigated the effects of lateral preference and personality on behaviour towards a manual sorting task. Eighty-five participants completed laterality and personality scales and a card-sorting task. Degree of hand preference was found to influence behaviour towards the task with strong left-handers taking longer to begin. Those with a left congruent lateral preference (left-hand, left-ear) took significantly longer to begin the task than those with a right congruent preference. Neither neuroticism nor extraversion influenced task approach. We concluded that hand preference, and more specifically a strong left-hand preference is a good predictor of a longer initiation time on a manual task. Ear preference on its own does not predict initiation time

Transient activaton of β-catenin signalling in adult mouse epidermis is sufficient to induce new hair follicles but continuous activation is required to maintain hair follicle tumours

When β-catenin signalling is disturbed from mid-gestation onwards lineage commitment is profoundly altered in postnatal mouse epidermis. We have investigated whether adult epidermis has the capacity for β-catenin-induced lineage conversion without prior embryonic priming. We fused N-terminally truncated, stabilised β-catenin to the ligand-binding domain of a mutant oestrogen receptor (ΔNβ -cateninER). ΔNβ-cateninER was expressed in the epidermis of transgenic mice under the control of the keratin 14 promoter and β -catenin activity was induced in adult epidermis by topical application of 4-hydroxytamoxifen (4OHT). Within 7 days of daily 4OHT treatment resting hair follicles were recruited into the hair growth cycle and epithelial outgrowths formed from existing hair follicles and from interfollicular epidermis. The outgrowths expressed Sonic hedgehog, Patched and markers of hair follicle differentiation, indicative of de novo follicle formation. The interfollicular epidermal differentiation program was largely unaffected but after an initial wave of sebaceous gland duplication sebocyte differentiation was inhibited. A single application of 4OHT was as effective as repeated doses in inducing new follicles and growth of existing follicles. Treatment of epidermis with 4OHT for 21 days resulted in conversion of hair follicles to benign tumours resembling trichofolliculomas. The tumours were dependent on continuous activation of β-catenin and by 28 days after removal of the drug they had largely regressed. We conclude that interfollicular epidermis and sebaceous glands retain the ability to be reprogrammed in adult life and that continuous β-catenin signalling is required to maintain hair follicle tumours.Peer reviewedFinal Published versio

Air pollution and livestock production

The air in a livestock farming environment contains high concentrations of dust particles and gaseous pollutants. The total inhalable dust can enter the nose and mouth during normal breathing and the thoracic dust can reach into the lungs. However, it is the respirable dust particles that can penetrate further into the gas-exchange region, making it the most hazardous dust component. Prolonged exposure to high concentrations of dust particles can lead to respiratory health issues for both livestock and farming staff. Ammonia, an example of a gaseous pollutant, is derived from the decomposition of nitrous compounds. Increased exposure to ammonia may also have an effect on the health of humans and livestock. There are a number of technologies available to ensure exposure to these pollutants is minimised. Through proactive means, (the optimal design and management of livestock buildings) air quality can be improved to reduce the likelihood of risks associated with sub-optimal air quality. Once air problems have taken hold, other reduction methods need to be applied utilising a more reactive approach. A key requirement for the control of concentration and exposure of airborne pollutants to an acceptable level is to be able to conduct real-time measurements of these pollutants. This paper provides a review of airborne pollution including methods to both measure and control the concentration of pollutants in livestock buildings

Unintegrated parton distributions and electroweak boson production at hadron colliders

We describe the use of doubly-unintegrated parton distributions in hadron-hadron collisions, using the (z,k_t)-factorisation prescription where the transverse momentum of the incoming parton is generated in the last evolution step. We apply this formalism to calculate the transverse momentum (P_T) distributions of produced W and Z bosons and compare the predictions to Tevatron Run 1 data. We find that the observed P_T distributions can be generated almost entirely by the leading order q_1 q_2 -> W,Z subprocesses, using known and universal doubly-unintegrated quark distributions. We also calculate the P_T distribution of the Standard Model Higgs boson at the LHC, where the dominant production mechanism is by gluon-gluon fusion.Comment: 20 pages, 8 figures. Version to appear in Phys. Rev. D; correction to Higgs P_T distribution made in Erratu

Diffractive parton distributions: the role of the perturbative Pomeron

We consider the role of the perturbative Pomeron-to-parton splitting in the formation of the diffractive parton distributions.Comment: 8 pages, 4 figures. To appear in the proceedings of the 12th International Conference on Elastic and Diffractive Scattering: Forward Physics and QCD, DESY, Hamburg, Germany, 21-25 May 200

Effect of absorptive corrections on inclusive parton distributions

We study the effect of absorptive corrections due to parton recombination on the parton distributions of the proton. A more precise version of the GLRMQ equations, which account for non-linear corrections to DGLAP evolution, is derived. An analysis of HERA F_2 data shows that the small-x gluon distribution is enhanced at low scales when the absorptive effects are included, such that a negative gluon distribution at 1 GeV is no longer required.Comment: 10 pages, 3 figure