An examination of atmospheric lids during COPS

Copyright @ 2009 E.Schweizerbart Science PublishersThe understanding of the nature, origin and prevalence of atmospheric lids is low. There is, therefore, an opportunity to contribute significantly to this area of meteorology - this is the goal of this work. The context for this paper is the Convective and Orographically-induced Precipitation Study (COPS). The COPS observational campaign, which was undertaken in 2007, was based around the Black Forest region with the aim of improving precipitation forecasts in low mountainous regions. However, the project also represents a great data archive with which to analyse isolated features, such as atmospheric lids. In short, lids play a vital role in the development of convective storms. For example, evidence from the Convective Storm Initiation Project (CSIP), which was run in the UK in 2005, has shown that lids are important not only in determining whether a storm occurs but also when and where they develop and how intense they are – sometimes, counterintuitively, they appear to increase the intensity. This extended abstract is intended as a brief overview of the previous literature on lids in order to place the work presented at ICAM-2009 in the wider scientific context.This work is funded by the Natural Environment Research Council (NERC)

Multiple traffic signal control using a genetic algorithm

Optimising traffic signal timings for a multiple-junction road network is a difficult but important problem. The essential difficulty of this problem is that the traffic signals need to coordinate their behaviours to achieve the common goal of optimising overall network delay. This paper discusses a novel approach towards the generation of optimal signalling strategies, based on the use of a genetic algorithm (GA). This GA optimises the set of signal timings for all junctions in network. The different efficient red and green times for all the signals are determined by genetic algorithm as well as the offset time for each junction. Previous attempts to do this rely on a fixed cycle time, whereas the algorithm described here attempts to optimise cycle time for each junction as well as proportion of green times. The fitness function is a measure of the overall delay of the network. The resulting optimised signalling strategies were compared against a well-known civil engineering technique, and conclusions drawn

Spatial variation in the MRE throughout the Scottish Post-Roman to late Medieval period: North Sea values (500-1350 BP)

The marine radiocarbon reservoir effect (MRE) occurs as a spatially and temporally dependent variable owing to localized changes in oceanic water composition. This study investigates ΔR values (deviations from the global average MRE whose ΔR = 0) during the period 500–1350 BP for the east coast of Scotland, where a complex estuarine system exists that drains into the semi-enclosed North Sea basin. Due to the availability of suitable archaeological samples, the data set has a distinct Medieval focus that spans the area from Aberdeen in the north to East Lothian in the south. Many of the ΔR values are not significantly different from 0 (the global average), but there are occasional excursions to negative values (max –172 ± 20) indicating the presence of younger water. These values show greater variability compared to other published data for this general region, suggesting that considerable care must be taken when dating marine derived samples from archaeological sites on the east coast of Scotland

Three-dimensional modeling of lightning-induced electromagnetic pulses on Venus, Jupiter and Saturn

While lightning activity in Venus is still controversial, its existence in Jupiter and Saturn was first detected by the Voyager missions and later on confirmed by Cassini and New Horizons optical recordings in the case of Jupiter, and recently by Cassini on Saturn in 2009. Based on a recently developed 3D model we investigate the influence of lightning-emitted electromagnetic pulses (EMP) on the upper atmosphere of Venus, Saturn and Jupiter. We explore how different lightning properties such as total energy released and orientation (vertical, horizontal, oblique) can produce mesospheric transient optical emissions of different shapes, sizes and intensities. Moreover, we show that the relatively strong background magnetic field of Saturn can enhance the lightning-induced quasi-electrostatic and inductive electric field components above 1000 km of altitude producing stronger transient optical emissions that could be detected from orbital probes

340 years of atmospheric circulation characteristics reconstructed from an eastern Antarctic Peninsula ice core

Copyright @ 2006 American Geophysical Union (AGU)Precipitation delivery mechanisms for Dolleman Island (DI), located off the east coast of the Antarctic Peninsula, are investigated using reanalysis and back trajectory data. The Southern Annular Mode (SAM) and ENSO are both shown to influence precipitation delivery and event size. Precipitation delivery variability is compared against the interannual variation of chemical data from two DI ice cores. Nitrate concentration in the cores is strongly linked with the ratio of easterly to westerly back trajectories arriving at DI, as described by a Cross-Peninsula Index (CPI) defined in this paper. This CPI is used subsequently to reconstruct the atmospheric circulation characteristics for the 340-year ice core record. The analysis highlights a period of increased easterlies during 1720–1780 and an increase in westerlies for 1950–1980, the latter concomitant with a positive SAM trend and western Peninsula warming. The reconstruction also reveals periods when polynyas may have been present in the Weddell Sea

Comparison of data on Mutation Frequencies of Mice Caused by Radiation - Low Dose Model -

We propose LD(Low Dose) model, the extension of LDM model which was proposed in the previous paper [Y. Manabe et al.: J. Phys. Soc. Jpn. 81 (2012) 104004] to estimate biological damage caused by irradiation. LD model takes account of all the considerable effects including cell death effect as well as proliferation, apoptosis, repair. As a typical example of estimation, we apply LD model to the experiment of mutation frequency on the responses induced by the exposure to low levels of ionizing radiation. The most famous and extensive experiments are those summarized by Russell and Kelly [Russell, W. L. & Kelly, E. M: Proc. Natl Acad. Sci. USA 79 (1982) 539-541], which are known as 'Mega-mouse project'. This provides us with important information of the frequencies of transmitted specific-locus mutations induced in mouse spermatogonia stem-cells. It is found that the numerical results of the mutation frequency of mice are in reasonable agreement with the experimental data: the LD model reproduces the total dose and dose rate dependence of data reasonably. In order to see such dose-rate dependence more explicitly, we introduce the dose-rate effectiveness factor (DREF). This represents a sort of preventable effects such as repair, apoptosis and death of broken cells, which are to be competitive with proliferation effect of broken cells induced by irradiation.Comment: subimitting to J. Phys. Soc. Jpn, 32 pages, 8 figure

Fusion of neurohypophyseal membranes in vitro

Freeze cleaving electron microscopy has shown that fusion of isolated secretory vesicles from bovine neurohypophyses was induced by Ca 2+ in micromolar concentrations. Mg 2+ and Sr 2+ were ineffective. Mg 2+ inhibited Ca 2+-induced fusion. In suspensions containing secretory vesicles as well as sheets of cell membrane, release of vasopressin parallel to intervesicular fusion of secretory vesicles with sheets of cell membrane was observed after exposure to Ca 2+. Mg 2+ and Sr 2+ were ineffective in replacing Ca 2+ as trigger for fusion or vasopressin release. Intervesicular fusion and exocytotic profiles were observed when isolated neurohypophyses or neurosecretosome were exposed to cold

Barriers and predictors of medication use for childhood ADHD: findings from a UK population-representative cohort

This is the final version. Available from Springer Verlag via the DOI in this record.Purpose Little is known about sociodemographic and clinical factors that predict and act as barriers to ADHD medication independently of symptom severity. We examined the proportion of children using medication for ADHD, age of initiation of medication, and predictors of medication use in a population-representative cohort. Methods Data from the Millennium Cohort Study on child ADHD, medication use for ADHD at age 14 (in 2014–2015) and child, parent and sociodemographic variables were collated. Logistic regression models were used to identify factors that predict medication use for ADHD (the main outcome measure), adjusting for symptom severity at age seven. Results The weighted prevalence of ADHD was 3.97% (N = 11,708). 45.57% of children with ADHD (N = 305) were taking medication. The median age at initiation was 9 years (range 3–14). Male gender (AOR 3.66, 95% CI 1.75, 7.66) and conduct problems at age seven (AOR 1.24 95% CI 1.04, 1.47) and 14 predicted medication use at age 14 after adjusting for symptom severity. Conclusions Our study is the first to assess predictors of medication whist adjusting for ADHD symptom severity. Girls with ADHD were less likely to be prescribed medication, even when they displayed similar ADHD symptom levels to boys. Conduct problems also predicted medication independently of ADHD symptoms. ADHD may be more often medicated in boys because clinicians may think a prototypical ADHD child is male, and perhaps conduct problems make boys more disruptive in the classroom, leading to boys being more often treated.Wellcome Trus