Quantum Bayesian implementation

Bayesian implementation concerns decision making problems when agents have incomplete information. This paper proposes that the traditional sufficient conditions for Bayesian implementation shall be amended by virtue of a quantum Bayesian mechanism. In addition, by using an algorithmic Bayesian mechanism, this amendment holds in the macro world.Comment: 14 pages, 3 figure

Predicting seawater intrusion in coastal groundwater boreholes using self-potential data

Many coastal groundwater abstraction wells are under threat from seawater intrusion: this is exacerbated in summer by low water tables and increased abstraction. Existing hydrochemistry or geophysical techniques often fail to predict the timing of intrusion events. We investigate whether the presence and transport of seawater can influence self-potentials (SPs) measured within groundwater boreholes, with the aim of using SP monitoring to provide early warning of saline intrusion. SP data collection: SP data were collected from a coastal groundwater borehole and an inland borehole (> 60 km from the coast) in the Seaford Chalk of southern England. The SP gradient in the inland borehole was approximately 0.05 mV/m, while that in the coastal borehole varied from 0.16-0.26 mV/m throughout the monitoring period. Spectral analysis showed that semi-diurnal fluctuations in the SP gradient were several orders of magnitude higher at the coast than inland, indicating a strong influence from oceanic tides. A characteristic decrease in the gradient, or precursor, was observed in the coastal borehole several days prior to seawater intrusion. Modelling results: Hydrodynamic transport and geoelectric modelling suggest that observed pressure changes (associated with the streaming potential) are insufficient to explain either the magnitude of the coastal SP gradient or the semi-diurnal SP fluctuations. By contrast, a model of the exclusion-diffusion potential closely matches these observations and produces a precursor similar to that observed in the field. Sensitivity analysis suggests that both a sharp saline front and spatial variations in the exclusion efficiency arising from aquifer heterogeneities are necessary to explain the SP gradient observed in the coastal borehole. The presence of the precursor in the model depends also on the presence and depth of fractures near the base of the borehole. Conclusions: Our results indicate that SP monitoring, combined with hydrodynamic transport and geoelectric modelling, holds considerable promise as an early warning device for seawater intrusion. We now aim to refine our understanding of the technique by applying it to a range of aquifer types

Characterizing the Self‐Potential Response to Concentration Gradients in Heterogeneous Subsurface Environments

DJM was supported by NERC CASE studentship NE/I018417/1. Additional support was provided by NERC to MG under the Science and Solutions for a Changing Planet Doctoral Training Partnership, run by the Grantham Institute for Climate Change at Imperial College London. Two anonymous reviewers are thanked for their comments, which greatly helped to improve the manuscript. The authors would also like to thank Southern Water for access to the borehole at Saltdean. Atkins Global and Southern Water are thanked for some additional funding under the NERC CASE studentship. The laboratory components of this work were carried out with support from TOTAL who we gratefully acknowledged. All data supporting the conclusions of this work are available in the supporting information.Peer reviewedPublisher PD

High-pressure Raman study of L-alanine crystal

Pressure-dependent Raman scattering studies in the range 0.0 -- 32 kbar were carried out in L-alanine in order to investigate its external mode phonon spectra in relation to the phase transitions in the crystal. A careful analysis of the spectra shows that the low-energy Raman modes exhibit variation both in frequency and in intensity and between 26 and 28 kbar it is observed a splitting of a external mode, indicating that the D_2 normal phase undergoes a transition. Pressure coefficients for external modes are also given.Comment: 11 pages, Latex, 2 figure

Modelling boreholes in complex heterogeneous aquifers

Reliable estimates of the sustainable yield of supply boreholes are critical to ensure that groundwater resources are managed sustainably. Sustainable yields are dependent on the pumped groundwater level in a borehole, how this relates to vertical aquifer heterogeneity, and features of the borehole itself. This paper presents a 3D radial flow model (SPIDERR), based on the Darcy-Forchheimer equation, for simulating the groundwater level response in supply boreholes in unconfined, heterogeneous aquifers. The model provides a tool for investigating the causes of non-linear behaviour in abstraction boreholes, which can have a significant impact on sustainable yields. This is demonstrated by simulating a variable-rate pumping test in a Chalk abstraction borehole. The application suggests the non-linear response to pumping is due to a combination of factors: a reduction in well storage with depth due to changes in the borehole diameter, a reduction in hydraulic conductivity with depth, and non-Darcian flow

An integrated modelling approach for assessing the effect of multiscale complexity on groundwater source yields

A new multi-scale groundwater modelling methodology is presented to simulate pumped water levels in abstraction boreholes within regional groundwater models, providing a robust tool for assessing the sustainable yield of supply boreholes and improving our understanding of groundwater availability during drought. A 3D borehole-scale model, which solves the Darcy-Forchheimer equation in cylindrical co-ordinates to simulate both linear and non-linear radial flow to a borehole in a heterogeneous aquifer, is embedded within a Cartesian grid, using a hybrid radial-Cartesian finite difference method. The local-scale model is coupled to a regional groundwater model, ZOOMQ3D, using the OpenMI model linkage software, providing a flexible and efficient tool for assessing the behaviour of a groundwater source within its regional hydrogeological context during historic droughts and under climate change. The advantages of the new method are demonstrated through application to a Chalk supply borehole in the UK

Generalized surface current method in the macroscopic theory of diffraction radiation

The surface current method known in the theory of electromagnetic waves diffraction is generalized to be applied for the problems of diffraction radiation generated by a charged particle moving nearby an ideally-conducting screen in vacuum. An expression for induced surface current density leading to the exact results in the theory of transition radiation is derived, and by using this expression several exact solutions of diffraction radiation problems are found. Limits of applicability for the earlier known models based on the surface current conception are indicated. Properties of radiation from a semi-plane and from a slit in cylinder are investigated at the various distances to observer.Comment: 8 pages, 8 figure

The putative proteinase maturation protein A of Streptococcus pneumoniae is a conserved surface protein with potential to elicit protective immune responses

Surface-exposed proteins often play an important role in the interaction between pathogenic bacteria and their host. We isolated a pool of hydrophobic, surface-associated proteins of Streptococcus pneumoniae. The opsonophagocytic activity of hyperimmune serum raised against this protein fraction was high and species specific. Moreover, the opsonophagocytic activity was independent of the capsular type and chromosomal genotype of the pneumococcus. Since the opsonophagocytic activity is presumed to correlate with in vivo protection, these data indicate that the protein fraction has the potential to elicit species-specific immune protection with cross-protection against various pneumococcal strains. Individual proteins in the extract were purified by two-dimensional gel electrophoresis. Antibodies raised against three distinct proteins contributed to the opsonophagocytic activity of the serum. The proteins were identified by mass spectrometry and N-terminal amino acid sequencing. Two proteins were the previously characterized pneumococcal surface protein A and oligopeptide-binding lipoprotein AmiA. The third protein was the recently identified putative proteinase maturation protein A (PpmA), which showed homology to members of the family of peptidyl-prolyl cis/trans isomerases. Immunoelectron microscopy demonstrated that PpmA was associated with the pneumococcal surface. In addition, PpmA was shown to elicit species-specific opsonophagocytic antibodies that were cross-reactive with various pneumococcal strains. This antibody cross-reactivity was in line with the limited sequence variation of ppmA. The importance of PpmA in pneumococcal pathogenesis was demonstrated in a mouse pneumonia model. Pneumococcal ppmA-deficient mutants showed reduced virulence. The properties of PpmA reported here indicate its potential for inclusion in multicomponent protein vaccines