Taxonomy of some Galeommatoidea (Mollusca, Bivalvia) associated with deep-sea echinoids: A reassessment of the bivalve genera Axinodon Verrill & Bush, 1898 and Kelliola Dall, 1899 with descriptions of new genera Syssitomya gen. nov. and Ptilomyax gen. nov.

The type species of Axinodon ellipticus Verrill & Bush, 1898 and Kellia symmetros Jeffreys, 1876 are re-described. It is concluded that the two species are not conspecific and that K. symmetros cannot be placed in the genus Axinodon. The family affinity of Axinodon is not resolved, although it is probable that this genus belongs to the Thyasiridae. Kellia symmetros is the type species of Kelliola and is placed in the Montacutidae. Kelliola symmetros is most probably associated with the echinoid Aeropsis rostrata and is not the species previously recorded from North Atlantic Pourtalesia echinoids under the name of Axinodon symmetros. This commensal associated with the North Atlantic Pourtalesia is here described as new and placed in the new genus as Syssitomya pourtalesiana gen. nov. sp. nov., Syssitomya gen. nov. differs from all other genera in the Montacutidae by having laminar gill filaments modified for harbouring symbiotic bacteria and it is thus assumed to be chemosymbiotic. A montacutid associated with the hadal Pourtalesia heptneri is described as Ptilomyax hadalis gen. nov. sp. nov

Orbital Debris Environment Monitor (ODEM)

Viewgraphs on orbital debris environmental monitor (ODEM) are presented. Topics covered include: Long Duration Exposure Facility (LDEF); interplanetary dust experiment; orbital debris clouds; mapping and modeling of orbital debris clouds; and solar maximum mission spacecraft

The influence of geometry, surface character and flexibility on the permeation of ions and water through biological pores

A hydrophobic constriction site can act as an efficient barrier to ion and water permeation if its diameter is less than the diameter of an ion's first hydration shell. This hydrophobic gating mechanism is thought to operate in a number of ion channels, e.g. the nicotinic receptor, bacterial mechanosensitive channels (MscL and MscS) and perhaps in some potassium channels (e.g. KcsA, MthK, and KvAP). Simplified pore models allow one to investigate the primary characteristics of a conduction pathway, namely its geometry (shape, pore length, and radius), the chemical character of the pore wall surface, and its local flexibility and surface roughness. Our extended (ca. 0.1 \mu s) molecular dynamic simulations show that a short hydrophobic pore is closed to water for radii smaller than 0.45 nm. By increasing the polarity of the pore wall (and thus reducing its hydrophobicity) the transition radius can be decreased until for hydrophilic pores liquid water is stable down to a radius comparable to a water molecule's radius. Ions behave similarly but the transition from conducting to non-conducting pores is even steeper and occurs at a radius of 0.65 nm for hydrophobic pores. The presence of water vapour in a constriction zone indicates a barrier for ion permeation. A thermodynamic model can explain the behaviour of water in nanopores in terms of the surface tensions, which leads to a simple measure of "hydrophobicity" in this context. Furthermore, increased local flexibility decreases the permeability of polar species. An increase in temperature has the same effect, and we hypothesise that both effects can be explained by a decrease in the effective solvent-surface attraction which in turn leads to an increase in the solvent-wall surface free energy.Comment: Peer reviewed article appeared in Physical Biology http://www.iop.org/EJ/abstract/1478-3975/1/1/005

Electroweak and Bottom Quark Contributions to Higgs Boson plus Jet Production

This paper presents predictions for jet pseudorapidity (eta) and transverse momentum (p_T) distributions for the production of the Standard Model Higgs boson in association with a high-p_T hadronic jet. We discuss the contributions of electroweak loops and of bottom-quark parton processes to the cross section. The latter arise in the five-flavour scheme. Predictions for the Tevatron and the Large Hadron Collider with 10 TeV collision energy are presented. For Higgs boson masses of 120 GeV, 160 GeV and 200 GeV, we find the maximal effects of the electroweak contributions to the Higgs plus jet p_T and eta distribution to be -14 % and -5.3 %, respectively, for the Tevatron, and -3 % and -2 %, respectively, for the LHC. For the maximal contribution of bottom-quark parton processes to the p_T and eta distribution, we find +3 % and + 2.5 %, respectively, for the Tevatron, and +3.5 % and +3 %, respectively, for the LHC. A separate study of the Higgs + b-jet cross section demonstrates that a calculational approach which respects the hierarchies of Yukawa couplings yields a leading order cross section prediction which is more accurate in the high-p_T regime than conventional approaches.Comment: 25 pages, 14 figure

The intrinsic shapes of starless cores in Ophiuchus

Using observations of cores to infer their intrinsic properties requires the solution of several poorly constrained inverse problems. Here we address one of these problems, namely to deduce from the projected aspect ratios of the cores in Ophiuchus their intrinsic three-dimensional shapes. Four models are proposed, all based on the standard assumption that cores are randomly orientated ellipsoids, and on the further assumption that a core's shape is not correlated with its absolute size. The first and simplest model, M1, has a single free parameter, and assumes that the relative axes of a core are drawn randomly from a log-normal distribution with zero mean and standard deviation \sigma o. The second model, M2a, has two free parameters, and assumes that the log-normal distribution (with standard deviation \sigma o) has a finite mean, \mu o, defined so that \mu o<0 means elongated (prolate) cores are favoured, whereas \mu o>0 means flattened (oblate) cores are favoured. Details of the third model (M2b, two free parameters) and the fourth model (M4, four free parameters) are given in the text. Markov chain Monte Carlo sampling and Bayesian analysis are used to map out the posterior probability density functions of the model parameters, and the relative merits of the models are compared using Bayes factors. We show that M1 provides an acceptable fit to the Ophiuchus data with \sigma o ~ 0.57+/-0.06; and that, although the other models sometimes provide an improved fit, there is no strong justification for the introduction of their additional parameters.Comment: 10 pages, 8 figures. Accepted by MNRA

The opportunity cost of capital of US buyouts

This paper addresses the problem of accurately determining buyout opportunity cost of capital for performance analyses. It draws on a unique and proprietary set of data on 133 United States buyouts between 1984 and 2004. For each buyout, we determine a public market equivalent that matches the buyout in timing and systematic risk. We show that under realistic mimicking conditions, the average opportunity cost of capital is below the commonly used benchmark S&P 500. The surprising result has a simple explanation: ex post, many of the transactions mimicking the buyouts would have defaulted in the public market. Only under relaxed assumptions, is the average opportunity cost of capital close to the average index return. Our sensitivity analyses highlight the need for a comprehensive risk adjustment that considers both operating risk and leverage risk for an accurate assessment of buyout performance. This finding is particularly important as existing literature on this topic tends to rely on benchmarks without a proper risk adjustment.Private Equity; Risk-Adjusted Performance; Buyout; Benchmarking Alternative Assets;

Statistical Time Series Models of Pilot Control with Applications to Instrument Discrimination

A general description of the methodology used in obtaining the transfer function models and verification of model fidelity, frequency domain plots of the modeled transfer functions, numerical results obtained from an analysis of poles and zeroes obtained from z plane to s-plane conversions of the transfer functions, and the results of a study on the sequential introduction of other variables, both exogenous and endogenous into the loop are contained

A global protocol for monitoring of coral bleaching

Coral bleaching and subsequent mortality represent a major threat to the future health and productivity of coral reefs. However a lack of reliable data on occurrence, severity and other characteristics of bleaching events hampers research on the causes and consequences of this important phenomenon. This article describes a global protocol for monitoring coral bleaching events, which addresses this problem and can be used by people with different levels of expertise and resources

Code Usage Analysis System (CUAS)

A set of computer programs is offered to aid a user in evaluating performance of an application program. The system provides reports of subroutine usage, program errors, and segment loading which occurred during the execution of an application program. It is presented in support of the development and validation of the space vehicle dynamics project