The energy density of jellyfish: Estimates from bomb-calorimetry and proximate-composition

Two techniques are described to calculate energy densities for the bell, gonad and oral arm tissues of three scyphozoan jellyfish (Cyanea capillata, Rhizostoma octopus and Chrysaora hysoscella). First, bomb-calorimetry was used, a technique that is readily available and inexpensive. However, the reliability of this technique for gelatinous material is contentious. Second, further analysis involving the more labour intensive proximate-composition analysis (protein, fat and carbohydrate) was carried out on two species (C capillata and R. octopus). These proximate data were subsequently converted to energy densities. The two techniques (bomb-calorimetry and proximate-composition) gave very similar estimates of energy density. Differences in energy density were found both amongst different species and between different tissues of the same species. Mean ( +/- S.D.) energy density estimates for whole animals from bomb-calorimetry were 0.18 +/- 0.05, 0.11 +/- 0.04, and 0.10 +/- 0.03 kJ g wet mass(-1) for C. capillata, R. octopus, and C. hysoscella respectively. The implications of these low energy densities for species feeding on jellyfish are discussed. (c) 2007 Elsevier B.V. All rights reserved.

Developing a simple, rapid method for identifying and monitoring jellyfish aggregations from the air

Within the marine environment, aerial surveys have historically centred on apex predators, such as pinnipeds, cetaceans and sea birds. However, it is becoming increasingly apparent that the utility of this technique may also extend to subsurface species such as pre-spawning fish stocks and aggregations of jellyfish that occur close to the surface. In light of this, we tested the utility of aerial surveys to provide baseline data for 3 poorly understood scyphozoan jellyfish found throughout British and Irish waters: Rhizostoma octopus, Cyanea capillata and Chrysaora hysoscella. Our principal objectives were to develop a simple sampling protocol to identify and quantify surface aggregations, assess their consistency in space and time, and consider the overall applicability of this technique to the study of gelatinous zooplankton. This approach provided a general understanding of range and relative abundance for each target species, with greatest suitability to the study of R. octopus. For this species it was possible to identify and monitor extensive, temporally consistent and previously undocumented aggregations throughout the Irish Sea, an area spanning thousands of square kilometres. This finding has pronounced implications for ecologists and fisheries managers alike and, moreover, draws attention to the broad utility of aerial surveys for the study of gelatinous aggregations beyond the range of conventional ship-based techniques.

Estimating the masses of extra-solar planets

All extra-solar planet masses that have been derived spectroscopically are lower limits since the inclination of the orbit to our line-of-sight is unknown except for transiting systems. In theory, however, it is possible to determine the inclination angle, i, between the rotation axis of a star and an observer's line-of-sight from measurements of the projected equatorial velocity (v sin i), the stellar rotation period (P(rot)) and the stellar radius (R(*)). For stars which host planetary systems this allows the removal of the sin i dependency of extra-solar planet masses derived from spectroscopic observations under the assumption that the planetary orbits lie perpendicular to the stellar rotation axis.
We have carried out an extensive literature search and present a catalogue of v sin i, P(rot) and R(*) estimates for stars hosting extra-solar planets. In addition, we have used Hipparcos parallaxes and the Barnes-Evans relationship to further supplement the R(*) estimates obtained from the literature. Using this catalogue, we have obtained sin i estimates using a Markov-chain Monte Carlo analysis. This technique allows proper 1 Sigma two-tailed confidence limits to be placed on the derived sin i's along with the transit probability for each planet to be determined.
While we find that a small proportion of systems yield sin i's significantly greater than 1, most likely due to poor P(rot) estimations, the large majority are acceptable. We are further encouraged by the cases where we have data on transiting systems, as the technique indicates inclinations of similar to 90 degrees and high transit probabilities. In total, we are able to estimate the true masses of 133 extra-solar planets. Of these 133 extra-solar planets, only six have revised masses that place them above the 13M(J) deuterium burning limit; four of those six extra-solar planet candidates were already suspected to lie above the deuterium burning limit before correcting their masses for the sin i dependency. Our work reveals a population of high-mass extra-solar planets with low eccentricities, and we speculate that these extra-solar planets may represent the signature of different planetary formation mechanisms at work. Finally, we discuss future observations that should improve the robustness of this technique.

Dynamic Linear Precoding for the Exploitation of Known Interference in MIMO Broadcast Systems

This paper introduces a novel channel inversion (CI) precoding scheme for the downlink of phase shift keying (PSK)-based multiple input multiple output (MIMO) systems. In contrast to common practice where knowledge of the interference is used to eliminate it, the main idea proposed here is to use this knowledge to glean benefit from the interference. It will be shown that the system performance can be enhanced by exploiting some of the existent inter-channel interference (ICI). This is achieved by applying partial channel inversion such that the constructive part of ICI is preserved and exploited while the destructive part is eliminated by means of CI precoding. By doing so, the effective signal to interference-plus-noise ratio (SINR) delivered to the mobile unit (MU) receivers is enhanced without the need to invest additional transmitted signal power at the MIMO base station (BS). It is shown that the trade-off to this benefit is a minor increase in the complexity of the BS processing. The presented theoretical analysis and simulations demonstrate that due to the SINR enhancement, significant performance and throughput gains are offered by the proposed MIMO precoding technique compared to its conventional counterparts.

Evaluation of leukocyte dynamic in mouse retinal circulation with scanning laser ophthalmoloscopy (Video report)

http://bjo.bmj.com/content/suppl/2001/06/20/85.7.DC1 Leukocyte-endothelial cell interactions play an important role in the pathogenesis of various types of retinal vascular diseases, including diabetes, uveitis, and ischemic lesions. Over the last few years, several methods have been devised in which the scanning laser ophthalmoscope (SLO) is used to study leukocyte-endothelial interactions in vivo [1,2]. Previously we reported a noninvasive in vivo leukocyte tracking method using the SLO in rat. In this method, a nontoxic fluorescent agent (6-carboxyfluorescein diacetate, CFDA) was used to label leukocytes in vitro. Leukocyte velocities within the retinal and choroidal circulations were be quantified simultaneously [3]. None of the previous methods has been developed for imaging the murine fundus, mainly due to problems arising from the small size of the mouse eye. However, there are many advantages of using a murine model to study retinal vascular diseases such as enhanced genetic definition, increased range of reagents available for immunological studies and cost reduction. We have developed our SLO method such that we can track leukocytes in the mouse retinal and choroidal circulations.

Resonance-Raman probing of the interaction between dipyridophenazine complexes of ruthenium(II) and DNA

The resonance-Raman spectroscopic technique is an effective probe of the interaction between dipyridophenazine (dppz) complexes of ruthenium(II) and calf-thymus DNA, providing evidence that DNA addition results in changes to electronic transitions of the intercalating dppz ligand in both ground and excited states.

Security scanning at 94GHz - art. no. 62110C

It is well known that millimetre waves can pass through clothing. In short range applications such as in the scanning of people for security purposes, operating at W band can be an advantage. The size of the equipment is decreased when compared to operation at Ka band and the equipments have similar performance.

In this paper a W band mechanically scanned imager designed for imaging weapons and contraband hidden under clothing is discussed. This imager is based on a modified folded conical scan technology previously reported. In this design an additional optical element is added to give a Cassegrain configuration in image space. This increases the effective focal length and enables improved sampling of the image and provides more space for the receivers. This imager is constructed from low cost materials such as polystyrene, polythene and printed circuit board materials. The trade off between image spatial resolution and thermal sensitivity is discussed.

P2Y(1) antagonists: Combining receptor-based modeling and QSAR for a quantitative prediction of the biological activity based on consensus scoring

P2Y(1) is an ADP-activated G protein-coupled receptor (GPCR). Its antagonists impede platelet aggregation in vivo and are potential antithrombotic agents. Combining ligand and structure-based modeling we generated a consensus model (LIST-CM) correlating antagonist structures with their potencies. We docked 45 antagonists into our rhodopsin-based human P2Y(1) homology model and calculated docking scores and free binding energies with the Linear Interaction Energy (LIE) method in continuum-solvent. The resulting alignment was also used to build QSAR based on CoMFA, CoMSIA, and molecular descriptors. To benefit from the strength of each technique and compensate for their limitations, we generated our LIST-CM with a PLS regression based on the predictions of each methodology. A test set featuring untested substituents was synthesized and assayed in inhibition of 2-MeSADP-stimulated PLC activity and in radioligand binding. LIST-CM outperformed internal and external predictivity of any individual model to predict accurately the potency of 75% of the test set.

Map Width Enhancement Technique for a Turbocharger Compressor

This paper presents an investigation of map width enhancement and the performance improvement of a turbocharger compressor using a series of static vanes in the annular cavity of a classical bleed slot system. The investigation has been carried out using both experimental and numerical analysis. The compressor stage used for this study is from a turbocharger unit used in heavy duty diesel engines of approximately 300 kW. Two types of vanes were designed and added to the annular cavity of the baseline classical bleed slot system. The purpose of the annular cavity vane technique is to remove some of the swirl that can be carried through the bleed slot system, which would influence the pressure
ratio. In addition to this, the series of cavity vanes provides a better guidance to the slot recirculating flow before it mixes with the impeller main inlet flow. Better guidance of the flow improves the mixing at the inducer inlet in the circumferential direction. As a consequence, the stability of the compressor is improved at lower flow rates and a wider map can be achieved. The impact of two cavity vane designs on the map width and performance of the compressor was highlighted through a detailed analysis of the impeller flow field. The numerical and experimental study revealed that an effective vane design can improve the map width and pressure ratio characteristic without an efficiency penalty compared to the classical bleed slot system without vanes. The comparison study between the cavity vane and noncavity vane configurations presented in this paper showed that the map width was improved by 14.3% due to a significant reduction in surge flow and the peak pressure ratio was improved by 2.25% with the addition of a series of cavity vanes in the annular cavity of the bleed slot system.

The Birth of Shakespeare's Birthplace

"There is, indeed, little doubt,” the formidable scholar James Orchard Halliwell-Phillipps confidently explained to the Victorian readers of his Outlines of the Life of Shakespeare, “that the Birth-place did not become one of the incentives for pilgrimage until public attention had been specially directed to it at the time of the Jubilee.” That's broadly true. The earliest reference to the three-gabled, half-timbered house (two houses, originally) on Henley Street in Stratford-upon-Avon as the birthplace of William Shakespeare dates only from the late 1750s, when it was so named in Samuel Winter's town map. During the Stratford Jubilee, which David Garrick organized in 1769, the “small old house,” as the actor's first biographer called it, was fully recognized and promoted as the place where Shakespeare was born. Even so, Halliwell-Phillipps's observation conceals more than it reveals, because there is also little doubt that the dwelling that tradition calls Shakespeare's birthplace did not suddenly acquire that status during the first week of September 1769. The process by which the unremarkable piece of real estate that John Shakespeare purchased sometime in the late sixteenth century was transformed into what Barbara Hodgdon has rightly called the “controlling ideological center” of Shakespeare biography was long, slow, and far from inevitable. That process is the subject of this essay.

Serum eosinophil cationic protein (ECP):reference values in healthy nonatopic children

BACKGROUND: Although serum ECP concentrations have been reported in normal children, there are currently no published upper cutoff reference limits for serum ECP in normal, nonatopic, nonasthmatic children aged 1-15 years.
METHODS: We recruited 123 nonatopic, nonasthmatic normal children attending the Royal Belfast Hospital for Sick Children for elective surgery and measured serum ECP concentrations. The effects of age and exposure to environmental tobacco smoke (ETS) on the upper reference limits were studied by multiple regression and fractional polynomials.
RESULTS: The median serum ECP concentration was 6.5 microg/l and the 95th and 97.5 th percentiles were 18.8 and 19.9 microg/l. The median and 95th percentile did not vary with age. Exposure to ETS was not associated with altered serum ECP concentrations (P = 0.14).
CONCLUSIONS: The 95th and 97.5 th percentiles for serum ECP for normal, nonatopic, nonasthmatic children (aged 1-15 years) were 19 and 20 microg/l, respectively. Age and exposure to parental ETS did not significantly alter serum ECP concentrations or the normal upper reference limits. Our data provide cutoff upper reference limits for normal children for use of serum ECP in a clinical or research setting.
PMID: 10604557 [PubMed - indexed for MEDLINE]

Explaining levels of deprivation in the European Union

In this paper we seek to explain variations in levels of deprivation between EU countries. The starting-point of our analysis is the finding that the relationship between income and life-style deprivation varies across countries. Given our understanding of the manner in which the income-deprivation mismatch may arise from the limitations of current income as a measure of command over resources, the pattern of variation seems to be consistent with our expectations of the variable degree to which welfare-state regimes achieve 'decommodification' and smooth income flows. This line of reasoning suggests that cross-national differences in deprivation might, in significant part, be due not only to variation in household and individual characteristics that are associated with disadvantage but also to the differential impact of such variables across countries and indeed welfare regimes. To test this hypothesis, we have taken advantage of the ECHP (European Community Household Panel) comparative data set in order to pursue a strategy of substituting variable names for country/welfare regime names. We operated with two broad categories of variables, tapping, respectively, needs and resources. Although both sets of factors contribute independently to our ability to predict deprivation, it is the resource factors that are crucial in reducing country effects. The extent of cross-national heterogeneity depends on specifying the social class and situation in relation to long-term unemployment of the household reference person. The impact of the structural socio-economic variables that we label 'resource factors' varies across countries in a manner that is broadly consistent with welfare regime theory and is the key factor in explaining cross-country differences in deprivation. As a consequence, European homogeneity is a great deal more evident among the advantaged than the disadvantaged.

The Behavior of compressively loaded stiffener runout specimens - Part II: Finite element analysis

The termination of stiffeners in composite aircraft structures give rise to regions of high interlaminar shear and peel stresses as the load in the stiffener is diffused into the skin. This is of particular concern in co-cured composite stiffened structures where there is a relatively low resistance to through-thickness stress components at the skin-stiffener interface. In Part I, experimental results of tested specimens highlighted the influence of local design parameters on their structural response. Indeed some of the observed behavior was unexpected. There is a need to be able to analyse a range of changes in geometry rapidly to allow the analysis to form an integral part of the structural design process.

This work presents the development of a finite element methodology for modelling the failure process of these critical regions. An efficient thick shell element formulation is presented and this element is used in conjuction with the Virtual Crack Closure Technique (VCCT) to predict the crack growth characteristics of the modelled specimens. Three specimens were modelled and the qualitative aspects of crack growth were captured successfully. The shortcomings in the quantitative correlation between the predicted and observed failure loads are discussed. There was evidence to suggest that high through-thickness compressive stresses enhanced the fracture toughness in these critical regions.

Ocular anesthesia in the new millennium

In the new millennium anesthetic agents will be safer and more efficient. Topical anesthesia will be the most frequently used technique. Time- and cost-saving measures will expand the current trend of outpatient surgery and anesthesia will be reduced. Patients' perioperative comfort will improve.

Standing wave oscillations in an electrocatalytic reaction

Experimental standing wave oscillations of the interfacial potential across an electrode have been observed in the electrocatalytic oxidation of formic acid on a Pt ring working electrode. The instantaneous potential distribution was monitored by means of equispaced potential microprobes along the electrode. The oscillatory standing waves spontaneously arose from a homogeneous stationary state prior to a Hopf bifurcation if the reference electrode was placed close to the working electrode. Reduced electrolyte concentrations resulted in aperiodic potential patterns, while the presence of a sufficiently large ohmic resistance completely suppressed spatial inhomogeneities. The experimental findings confirm numerical predictions of a reaction-migration formalism: under the chosen geometry, a long-range negative potential coupling between distant points across the ring electrode can lead to oscillatory potential domains of distinct phase. It is further shown that the occurrence of oscillatory standing waves can be rationalized as the electrochemical equivalent of Turing's second bifurcation (wave bifurcation). In the presence of an external resistance, the coupling becomes positive throughout and leads to spatial synchronization.