Ubiquitous Nature of Multimode Vibrational Resonances in Positron-Molecule Annihilation

Positron annihilation on many molecules occurs via positron capture into vibrational Feshbach resonances, with annihilation rates often further enhanced by energy transfer to vibrational excitations weakly coupled to the positron continuum. Data presented here uncover another scenario in which the positron couples directly to a quasicontinuum of multimode vibrational states. A model that assumes excitation and escape from a statistically complete ensemble of multimode vibrations is presented that reproduces key features of the data.

British Constructions with Constitutions:The Formal and Informal Nature of 'Island' Relations on Montserrat and Gibraltar

This article explores social, economic and political relations on two British Dependent Territories (BDTs) -- Montserrat and Gibraltar. This article notes that though BDTs are British colonial constructions, created, sustained and modelled upon and by Britain, they differ from Britain in that they have political constitutions. They also exhibit an ambiguous dependence and independence upon and with Britain. This article goes on to look at social and economic relations on Montserrat and Gibraltar before comparing and contrasting the political climates on each BDT. Throughout this article, it is suggested that there is a dynamic tension between formal and informal aspects to managing life. Finally, this article concludes with a discussion about the suitability of the split between Executive and Legislative Councils in these two BDTs.

Towards a better understanding of the nature and contribution of the interflow to catchment dynamics.

A detailed understanding of flow and contaminant transfer along each of the key hydrological pathways within a catchment is critical for designing and implementing cost effective Programmes of Measures under the Water
Framework Directive.
The Contaminant Movement along Pathways Project (’The Pathways Project’) is an Irish, EPA STRIVE funded, large multi-disciplinary project which is focussed on understanding and modelling flow and attenuation along each of these pathways for the purposes of developing a catchment management tool. The tool will be used by EPA and RBD catchment managers to assess and manage the impacts of diffuse contamination on stream aquatic ecology. Four main contaminants of interest — nitrogen, phosphorus, sediment and pathogens — are being
investigated in four instrumented test catchments. In addition to the usual hydrological and water chemistry/quality parameters typically captured in catchment studies, field measurements at the test catchments include ecological
sampling, sediment dynamics, soil moisture dynamics, and groundwater levels and chemistry/quality, both during and between significant rainfall events. Spatial and temporal sampling of waters directly from the pathways of
interest is also being carried out.
Sixty-five percent of Ireland is underlain by poorly productive aquifers. In these hydrogeological settings, the main pathways delivering flow to streams are overland flow, interflow and shallow bedrock flow. Little is
known about the interflow pathway and its relative importance in delivery of flow and contaminants to the streams. Interflow can occur in both the topsoil and subsoil, and may include unsaturated matrix flow, bypass or macropore
flow, saturated flow in locally perched water tables and artificial field drainage.
Results to date from the test catchment experiments show that artificial field drains play an important role in the delivery of interflow to these streams, during and between rainfall events when antecedent conditions are
favourable. Hydrochemical mixing models, using silica and SAC254 (the absorbance of UV light at a wavelength of 254 nm which is a proxy for dissolved organic matter) as tracers, show that drain flow is an important end
member contributing to the stream and that proportionally, its contribution is relatively high.
Results from the study also demonstrate that waters originating from one pathway often mix with the waters from another, and are subsequently delivered to the stream at rates, and with chemical/quality characteristics,
that are not typical of either pathway. For example, pre-event shallow groundwater not far from the catchment divide comes up to the surface as rejected recharge during rainfall events and is rapidly delivered to the stream
via overland flow and/or artificial land drainage, bringing with it higher nitrate than would often be expected from a quickflow pathway contribution. This is contrary to the assumption often made in catchment studies that the
deeper hydrological pathways have slower response times in stream hydrographs during a rainfall event, and it emphasizes that it is critical to have a strong three-dimensional conceptual model as the basis for the interpretation
of catchment data.

A genome-wide association study provides evidence for association of chromosome 8p23 (MYP10) and 10q21.1 (MYP15) with high myopia in the French population.

PURPOSE. Myopia is a complex trait affected by both genetic and environmental factors. High myopia is associated with increased risk of sight-threatening eye disorders such as retinal detachment. The purpose of this genome-wide association study was to identify susceptibility genes contributing to high myopia in the French population. METHODS. High myopic cases were genotyped using Affymetrix SNP 6.0 chips and population controls were selected from the GABRIEL French dataset in which samples were genotyped by Illumina Human610 quad array. The association study was conducted using 152,234 single nucleotide polymorphisms that were present on both manufacturers' chips in 192 high myopic cases and 1064 controls to identify associated regions. Imputation was performed on peak regions. RESULTS. Associations were found at known myopia locus MYP10 on chromosome 8p23 and MYP15 on chromosome 10q21.1. Rs189798 (8p23) and rs10825992 (10q21.1) showed the strongest associations in these regions (P=6.32x10-7 and P=2.17x10-5, respectively). The imputed results at 8p23 showed 2 peaks of interest. The first spanned 30kb including rs189798 between MIR4660 and PPP1R3B with the most significant association at rs17155227 (P=1.07x10-10). The second novel peak was 4kb in length, encompassing MIR124-1 and the MSRA gene, with the strongest association at rs55864141 (P=1.30x10-7). The peak of imputed data at 10q21.1 was 70kb in length between ZWINT and MIR3924, with rs3107503 having the lowest P value (P=1.54x10-7). CONCLUSION. We provide evidence for the association of MYP10 at 8p23 and MYP15 at 10p21.1 with high myopia in the French population and refine these regions of association.

The nature of arsenic-phytochelatin complexes in Holcus lanatus and Pteris cretica

We have developed a method to extract and separate phytochelatins (PCs)-metal(loid) complexes using parallel metal(loid)-specific (inductively coupled plasma-mass spectrometry) and organic-specific (electrospray ionization-mass spectrometry) detection systems-and use it here to ascertain the nature of arsenic (As)-PC complexes in plant extracts. This study is the first unequivocal report, to our knowledge, of PC complex coordination chemistry in plant extracts for any metal or metalloid ion. The As-tolerant grass Holcus lanatus and the As hyperaccumulator Pteris cretica were used as model plants. In an in vitro experiment using a mixture of reduced glutathione (GS), PC(2), and PC(3), As preferred the formation of the arsenite [As((III))]-PC(3) complex over GS-As((III))-PC(2), As((III))-(GS)(3), As((III))-PC(2), or As((III))-(PC(2))(2) (GS: glutathione bound to arsenic via sulphur of cysteine). In H. lanatus, the As((III))-PC(3) complex was the dominant complex, although reduced glutathione, PC(2), and PC(3) were found in the extract. P. cretica only synthesizes PC(2) and forms dominantly the GS-As((III))-PC(2) complex. This is the first evidence, to our knowledge, for the existence of mixed glutathione-PC-metal(loid) complexes in plant tissues or in vitro. In both plant species, As is dominantly in non-bound inorganic forms, with 13% being present in PC complexes for H. lanatus and 1% in P. cretica.

Promotion of Ceria Catalysts by Precious Metals: Changes in Nature of the Interaction under Reducing and Oxidizing Conditions

By depositing ceria over supported precious metal (PM) catalysts and characterizing them with in situ diffuse reflectance UV (DR UV) and in situ Raman spectroscopy, we have been able to prove a direct correlation between a decrease in ceria band gap and the work function of the metal under reducing conditions. The PM ceria interaction results in changes on the ceria side of the metal ceria interface, such that the degree of oxygen vacancy formation on the ceria surface also correlates with the precious metal work function. Nevertheless, conclusive evidence for a purely electronic interaction could not be provided by X-ray photoelectron spectroscopy (XPS) analysis. On the contrary, the results highlight the complexity of the PM ceria interaction by supporting a spillover mechanism resulting from the electronic interaction under reducing conditions. Under oxidizing conditions, another effect has been observed; namely, a structural modification of ceria induced by the presence of PM cations. In particular, we have been able to demonstrate by in situ Raman spectroscopy that, depending on the PM ionic radius, it is possible to create PM ceria solid solutions. We observed that this structural modification prevails under an oxidizing atmosphere, whereas electronic and chemical interactions take place under reducing conditions.