Physical properties and micromorphology of till deposits from Talla Earth Observatory, Southern Uplands, Scotland

This factual report describes the 2007 field program at BGS’ Talla Earth Observatory, in the Scottish Southern Uplands, UK. The work involved 12 trial pits with logging of pit walls, soil sampling for particle size analysis and undisturbed sampling for thin sections and micromorphological analysis of a till and a hard pan in moranic deposits. The tills of the Langholm Till Formation (of McMillan & Merritt, 2012) are technically ‘coarse soils’ from a BS5930:1999 ground engineering perspective; typically very dense/hard, very wellgraded silty sandy gravels with a matrix dominated by silt and sand. In thin section the till sandmatrix-supported gravel clasts show a preferred alignment orientated suggesting a micro-fabric indicative of a subglacially deposited till. Clast lithology includes sandstone, siltstone and mudstone, and are consistent with the local bedrock lithology. Cobbles and boulders are often ‘very strong’ from a geotechnical perspective, but may have weaker ‘rotten’ crust in valley floor settings. The work provides new data on the geotechnical properties of Scottish tills and enhances our understanding of the physical and hydrological properties of commonly encountered Quaternary deposits that occur in the Talla Burn and nearby upland catchments

Marine benthic flora and fauna of Gourdon Bay and the Dampier Peninsula in the Kimberley region of North-Western Australia

Surveys undertaken to characterise the marine benthic habitats along the Dampier Peninsula and further south at Gourdon Bay in the Kimberley region of Western Australia were augmented with epibenthic sled sampling of soft and hard bottom habitats. This paper describes the species collected, their biomass and relative abundance for the main groups of marine macrophytes and invertebrates. Five localities were surveyed; Gourdon Bay, Quondong Point to Coulomb Point, Carnot Bay to Beagle Bay, Perpendicular Head and Packer Island. Sampling was limited to fifteen epibenthic dredge operations from a range of habitat types and was designed to target the most common habitat types and to obtain species identifications of the most important species and those which typified different habitat types. Surveys covered a total of 1,350 m 2 of seabed in depths between 11 and 23m. We identified 415 taxa comprising: 1 seagrass, 43 algae, 52 sponges, 30 ascidians, 10 hydroids, 14 scleractinian corals, 52 other cnidarians, 69 crustaceans, 73 molluscs and 71 echinoderms. Despite the limited nature of the sampling, a significant number of new species, range extensions and new records for Western Australia and Australia were recorded. Within the algae, one range extension (Halimeda cf. cuneata f. digitata not previously recorded in Western Australia) and one possible new species of Areschougia were recorded. Two range extensions were present in the ascidians; the solitary ascidian Polycarpa cf. intonata has previously only been recorded in Queensland and Cnemidocarpa cf. radicosa only in temperate Australian waters. There were several range extensions for the crustacea, for example, the sponge crab, Tumidodromia dormia, has only been recorded in Queensland. One species of holothurian of the genus Phyllophorus could not be identified from the literature available and may represent a new species. Similarly, a small species of the echinoid Gymnechinus could possibly be a new species. The collections of hydroids, hard corals, crinoids and molluscs contained no new species or range extensions. There was difficulty in identification of some groups to species level due to the status of the current taxonomic literature (e.g. Cnidaria, Porifera and ascidians) and there may be a number of new species among the material collected. Among the anthozoa, there is at least one new species of Chromonephthea and potentially 10 range extensions to Western Australia. Sinularia cf. acuta and Chromonephthea curvata are both new records for Australia with both previously recorded in Indonesia only. Among the better known taxa (e.g. molluscs, echinoderms, corals), most of the taxa identified to species level have been recorded to occur throughout north-western Australia, however the diversity recorded in this study is less than other parts of the Kimberley and this is almost certainly a result of the small overall area sampled and the single method of collection utilised. The most important species on soft bottom habitats in terms of biomass was the heart urchin Breynia desorii (up to 326 g.m -2). Sponges were the dominant fauna by biomass (up to 620 g.m -2) on hard bottom habitats and biomass was dominated a by a few large cup and massive sponge species (e.g. Pione velans and two unidentified Spheciospongia). The biomass of other filter feeders, especially ascidians (e.g. Aplidium cf. crateriferum), soft corals (e.g. Chromonephthea spp.), gorgonians (e.g. Junceella fragilis and Dichotella gemmacea) was also high, indicating the importance of these groups in characterising hard bottom habitats. Although low in biomass, crinoids such as Comaster multifidus and Comatula pectinata were abundant in samples that included a high biomass of other filter feeders

Phase Coherence and Control of Stored Photonic Information

We report the demonstration of phase coherence and control for the recently developed "light storage" technique. Specifically, we use a pulsed magnetic field to vary the phase of atomic spin excitations which result from the deceleration and storing of a light pulse in warm Rb vapor. We then convert the spin excitations back into light and detect the resultant phase shift in an optical interferometric measurement. The coherent storage of photon states in matter is essential for the practical realization of many basic concepts in quantum information processing.Comment: 5 pages, 3 figures. Submitted to Phys. Rev. Let

Plasma Turbulence in the Local Bubble

Turbulence in the Local Bubble could play an important role in the thermodynamics of the gas that is there. The best astronomical technique for measuring turbulence in astrophysical plasmas is radio scintillation. Measurements of the level of scattering to the nearby pulsar B0950+08 by Philips and Clegg in 1992 showed a markedly lower value for the line-of-sight averaged turbulent intensity parameter $$than is observed for other pulsars, consistent with radio wave propagation through a highly rarefied plasma. In this paper, we discuss the observational progress that has been made since that time. At present, there are four pulsars (B0950+08, B1133+16, J0437-4715, and B0809+74) whose lines of sight seem to lie mainly within the local bubble. The mean densities and line of sight components of the interstellar magnetic field along these lines of sight are smaller than nominal values for pulsars, but not by as much expected. Three of the four pulsars also have measurements of interstellar scintillation. The value of the parameter$$ is smaller than normal for two of them, but is completely nominal for the third. This inconclusive status of affairs could be improved by measurements and analysis of ``arcs'' in ``secondary spectra'' of pulsars.Comment: Submitted to Space Science Reviews as contribution to Proceedings of ISSI (International Space Science Institute) workshop "From the Heliosphere to the Local Bubble". Refereed version accepted for publicatio

Cartan subalgebras in C*-algebras of Hausdorff etale groupoids

The reduced $C^*$-algebra of the interior of the isotropy in any Hausdorff \'etale groupoid $G$ embeds as a $C^*$-subalgebra $M$ of the reduced $C^*$-algebra of $G$. We prove that the set of pure states of $M$ with unique extension is dense, and deduce that any representation of the reduced $C^*$-algebra of $G$ that is injective on $M$ is faithful. We prove that there is a conditional expectation from the reduced $C^*$-algebra of $G$ onto $M$ if and only if the interior of the isotropy in $G$ is closed. Using this, we prove that when the interior of the isotropy is abelian and closed, $M$ is a Cartan subalgebra. We prove that for a large class of groupoids $G$ with abelian isotropy---including all Deaconu--Renault groupoids associated to discrete abelian groups---$M$ is a maximal abelian subalgebra. In the specific case of $k$-graph groupoids, we deduce that $M$ is always maximal abelian, but show by example that it is not always Cartan.Comment: 14 pages. v2: Theorem 3.1 in v1 incorrect (thanks to A. Kumjain for pointing out the error); v2 shows there is a conditional expectation onto $M$ iff the interior of the isotropy is closed. v3: Material (including some theorem statements) rearranged and shortened. Lemma~3.5 of v2 removed. This version published in Integral Equations and Operator Theor

3D macro- and microfabric analyses of Neoproterozoic diamictites from the Valjean Hills, California (United States)

The Cryogenian interval (720–635 Ma) is famous for a rich archive of diamictites, many of which were deposited during glaciations. Classic examples are exposed in the Kingston Peak Formation of the Valjean Hills, near Death Valley (United States), with previous work pointing to multiple glacial cycles in other outcrop belts. Within any glacial period, diamictites are widespread, and in addition, their mechanics of deposition are highly variable. Some are massive in appearance at outcrop or in hand specimens and apparently lack any information that allows their mode of emplacement to be elucidated. Yet, the correct interpretation for deep-time successions in this area is especially important, since it is debated whether the diamictites are either associated with a tectonically driven origin, associated with rifting at the south-western Laurentian margin alongside slope-controlled gravitational mass movement, or predominantly deposited as (sub)glacial diamictites. In this paper, we demonstrate how diamictite texture can be objectively quantified based on clast orientations, at both macroscale and microscale (micromorphology), guiding interpretations. Our method is based on a technique used for Quaternary sediments, by mapping the apparent longest axes of skeleton grains (ranging from fine-grained sand to fine-grained pebbles) in oriented thin sections and reconstructing their microfabric in a 3D space coupled with macrofabric data for each diamictite. In this way, we could identify a bimodal signal in the orientation of the longest axes for each sample. Evidence for shearing and soft sediment deformation supports either subaqueous or subglacial deposition with deformation induced by basal sliding with a paleoflow directed toward the southeast. Our combined approach of micro- and macrofabric analyses can also encourage acquiring accurate fabric data for seemingly structureless diamictites from other deep-time rock archives in an objective manner

The Role of Cohabitating Partner and Relationship Characteristics on Physical Activity among Individuals with Osteoarthritis

Background: Most individuals with knee or hip osteoarthritis do not meet recommendations for physical activity. The Social Cognitive Theory suggests that the social environment (e.g., spouses/partners) may influence the physical activity of individuals with osteoarthritis. The purpose of this study was to examine whether the physical activity of insufficiently active, coupled adults with osteoarthritis was associated with received partner support for physical activity, partner’s engagement in physical activity, and relationship satisfaction. Methods: Cross-sectional data from 169 couples were collected. Accelerometers estimated moderate-to-vigorous physical activity and daily steps for participants with osteoarthritis and their partners. Participants with osteoarthritis reported total received partner support for physical activity and relationship satisfaction. Results: Participants with osteoarthritis were on average 65 years old, 65% female, 86% non-Hispanic white, and 47% retired. Receiving total partner support more frequently was associated with more minutes of moderate-to-vigorous physical activity but not with steps. Relationship satisfaction moderated the association of partner’s physical activity on the daily steps of individuals with osteoarthritis such that having a partner who accomplished more daily steps was associated with participants with osteoarthritis accomplishing more daily steps themselves when they reported greater relationship satisfaction. Conclusions: Partners and relationship satisfaction may play an important role in the physical activity of individuals with osteoarthritis. Interventions seeking to increase physical activity in this population may be enhanced by promoting partner support. Additional research is needed to further explain these associations within the context of relationship satisfaction

Inhibiting decoherence via ancilla processes

General conditions are derived for preventing the decoherence of a single two-state quantum system (qubit) in a thermal bath. The employed auxiliary systems required for this purpose are merely assumed to be weak for the general condition while various examples such as extra qubits and extra classical fields are studied for applications in quantum information processing. The general condition is confirmed with well known approaches towards inhibiting decoherence. A novel approach for decoherence-free quantum memories and quantum operations is presented by placing the qubit into the center of a sphere with extra qubits on its surface.Comment: pages 8, Revtex

Reflection and Ducting of Gravity Waves Inside the Sun

Internal gravity waves excited by overshoot at the bottom of the convection zone can be influenced by rotation and by the strong toroidal magnetic field that is likely to be present in the solar tachocline. Using a simple Cartesian model, we show how waves with a vertical component of propagation can be reflected when traveling through a layer containing a horizontal magnetic field with a strength that varies with depth. This interaction can prevent a portion of the downward-traveling wave energy flux from reaching the deep solar interior. If a highly reflecting magnetized layer is located some distance below the convection zone base, a duct or wave guide can be set up, wherein vertical propagation is restricted by successive reflections at the upper and lower boundaries. The presence of both upward- and downward-traveling disturbances inside the duct leads to the existence of a set of horizontally propagating modes that have significantly enhanced amplitudes. We point out that the helical structure of these waves makes them capable of generating an alpha-effect, and briefly consider the possibility that propagation in a shear of sufficient strength could lead to instability, the result of wave growth due to over-reflection.Comment: 23 pages, 5 figures. Accepted for publication in Solar Physic

Localization by disorder in the infrared conductivity of (Y,Pr)Ba2Cu3O7 films

The ab-plane reflectivity of (Y{1-x}Prx)Ba2Cu3O7 thin films was measured in the 30-30000 cm-1 range for samples with x = 0 (Tc = 90 K), x = 0.4 (Tc = 35 K) and x = 0.5 (Tc = 19 K) as a function of temperature in the normal state. The effective charge density obtained from the integrated spectral weight decreases with increasing x. The variation is consistent with the higher dc resistivity for x = 0.4, but is one order of magnitude smaller than what would be expected for x = 0.5. In the latter sample, the conductivity is dominated at all temperatures by a large localization peak. Its magnitude increases as the temperature decreases. We relate this peak to the dc resistivity enhancement. A simple localization-by-disorder model accounts for the optical conductivity of the x = 0.5 sample.Comment: 7 pages with (4) figures include