Non-invasive investigations of a wall painting using optical coherence tomography and hyperspectral imaging

Multispectral and hyperspectral imaging are efficient methods of measuring spectral reflectance at high spatial resolution. This non-invasive technique has been applied to the imaging of paintings over the last 20 years. PRISMS (Portable Remote Imaging System for Multispectral Scanning) was designed specifically for imaging wall paintings. Optical Coherence Tomography (OCT) is a low coherence interferometric technique capable of fast non-invasive imaging of subsurface microstructure. This paper shows the first application of in situ OCT imaging of a wall painting. The combination of PRISMS and OCT gives information on the varnish and paint layer structure, pigment identification, the state of degradation of the paint and varnish layers and informing curators on the painting schemes and techniques

ArDM: a ton-scale liquid Argon experiment for direct detection of Dark Matter in the Universe

The ArDM project aims at developing and operating large noble liquid detectors to search for direct evidence of Weakly Interacting Massive Particle (WIMP) as Dark Matter in the Universe. The initial goal is to design, assemble and operate a $\approx$1 ton liquid Argon prototype to demonstrate the feasibility of a ton-scale experiment with the required performance to efficiently detect and sufficiently discriminate backgrounds for a successful WIMP detection. Our design addresses the possibility to detect independently ionization and scintillation signals. In this paper, we describe this goal and the conceptual design of the detector.Comment: 5 pages, 3 figures, Talk given at IXth international conference on Topics in Astroparticle and Underground Physics (TAUP05), Zaragoza, (Spain

Ongoing over-exploitation and delayed responses to environmental change highlight the urgency for action to promote vertebrate recoveries by 2030

To safeguard nature, we must understand the drivers of biodiversity loss. Time-delayed biodiversity responses to environmental changes (ecological lags) are often absent from models of biodiversity change, despite their well-documented existence. We quantify how lagged responses to climate and land-use change have influenced mammal and bird populations around the world, while incorporating effects of direct exploitation and conservation interventions. Ecological lag duration varies between drivers, vertebrate classes and body size groupings-e.g. lags linked to climate-change impacts are 13 years for small birds, rising to 40 years for larger species. Past warming and land conversion generally combine to predict population declines; however, such conditions are associated with population increases for small mammals. Positive effects of management (>+4% annually for large mammals) and protected areas (>+6% annually for large birds) on population trends contrast with the negative impact of exploitation (<-7% annually for birds), highlighting the need to promote sustainable use. Model projections suggest a future with winners (e.g. large birds) and losers (e.g. medium-sized birds), with current/recent environmental change substantially influencing abundance trends to 2050. Without urgent action, including effective conservation interventions and promoting sustainable use, ambitious targets to stop declines by 2030 may already be slipping out of reach

The effects of sharing an experience on social interest in children and young adults with Autistic Spectrum Disorder and traits of Autistic Spectrum Disorder

Sharing an experience is seen to increase liking and create bonds in typical individuals. Individuals with Autistic Spectrum Disorder (ASD) are typically isolated; they do not to appear have the skills necessary to form bonds with others. The current research used an intervention consisting of listening to music to cause those with ASD to share an experience with a confederate. There were two conditions; one where the participant and confederate listened to the same piece of music, one where they listened to different music. 24 participants with ASD and traits of ASD took part in the study. A modified version of Nadel et al's (2000) still-face task was used as an observation measure, along with ratings in the intervention phase. A trend was seen in the overall differences between the two conditions. Social interest appeared to increase in the same music condition from before the intervention to after. Participants moved further away from the confederate but this was correlated with turning to face them, implying that sharing an experience with someone encourages eye-to-face and eye contact with that person. Findings from the present research suggest that sharing an experience with a partner increases social interest in that person. This could be the important first step in forming bonds with individuals with ASD

Synaptic tagging and capture : differential role of distinct calcium/calmodulin kinases in protein synthesis-dependent long-term potentiation

Weakly tetanized synapses in area CA1 of the hippocampus that ordinarily display long-term potentiation lasting ~3 h (called early-LTP) will maintain a longer-lasting change in efficacy (late-LTP) if the weak tetanization occurs shortly before or after strong tetanization of an independent, but convergent, set of synapses in CA1. The synaptic tagging and capture hypothesis explains this heterosynaptic influence on persistence in terms of a distinction between local mechanisms of synaptic tagging and cell-wide mechanisms responsible for the synthesis, distribution, and capture of plasticity-related proteins (PRPs). We now present evidence that distinct CaM kinase (CaMK) pathways serve a dissociable role in these mechanisms. Using a hippocampal brain-slice preparation that permits stable long-term recordings in vitro for >10 h and using hippocampal cultures to validate the differential drug effects on distinct CaMK pathways, we show that tag setting is blocked by the CaMK inhibitor KN-93 (2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)amino-N-(4-chlorocinnamyl)-N-methylbenzylamine) that, at low concentration, is more selective for CaMKII. In contrast, the CaMK kinase inhibitor STO-609 [7H-benzimidazo(2,1-a)benz(de)isoquinoline-7-one-3-carboxylic acid] specifically limits the synthesis and/or availability of PRPs. Analytically powerful three-pathway protocols using sequential strong and weak tetanization in varying orders and test stimulation over long periods of time after LTP induction enable a pharmacological dissociation of these distinct roles of the CaMK pathways in late-LTP and so provide a novel framework for the molecular mechanisms by which synaptic potentiation, and possibly memories, become stabilized

Low energy neutron propagation in MCNPX and GEANT4

Simulations of neutron background from rock for underground experiments are presented. Neutron propagation through two types of rock, lead and hydrocarbon material is discussed. The results show a reasonably good agreement between GEANT4, MCNPX and GEANT3 in transporting low-energy neutrons.Comment: 9 Figure

Measurements of Scintillation Efficiency and Pulse-Shape for Low Energy Recoils in Liquid Xenon

Results of observations of low energy nuclear and electron recoil events in liquid xenon scintillator detectors are given. The relative scintillation efficiency for nuclear recoils is 0.22 +/- 0.01 in the recoil energy range 40 keV - 70 keV. Under the assumption of a single dominant decay component to the scintillation pulse-shape the log-normal mean parameter T0 of the maximum likelihood estimator of the decay time constant for 6 keV < Eee < 30 keV nuclear recoil events is equal to 21.0 ns +/- 0.5 ns. It is observed that for electron recoils T0 rises slowly with energy, having a value ~ 30 ns at Eee ~ 15 keV. Electron and nuclear recoil pulse-shapes are found to be well fitted by single exponential functions although some evidence is found for a double exponential form for the nuclear recoil pulse-shape.Comment: 11 pages, including 5 encapsulated postscript figure

A model for uranium mobility in groundwater in the Grand Pré region, Nova Scotia, Canada

Elevated levels of uranium that surpass maximum allowable concentrations have been recognized in some well water samples throughout Nova Scotia. In this study we examine the influence of redox conditions and regional geology on the mobility of uranium in groundwater in the Grand Pré region, located in the eastern end of the Annapolis-Cornwallis Valley in southwestern Nova Scotia. The study site is underlain by carbon-rich shale and arkosic sandstone of the Late Mississippian Horton Bluff Formation and the arenaceous sandstone of the Triassic Wolfville Formation. Water samples from drilled wells were analyzed on site for various water quality parameters (pH, conductivity, temperature, dissolved oxygen) and in the laboratory to determine alkalinity and cation (72) and major anion (9) concentrations. Several samples exceeded Health Canada (2011) limits for uranium (20 μg/L) with values up to 50.8 μg/L and aesthetic objectives (AO) for iron (up to 605 μg/L), manganese (up to 2.28 mg/L) and other cations. Data show that different redox conditions occur in the study area. The geospatial arrangement of the chemical data suggests that the lithology of the underlying aquifer strongly influences the availability of uranium in groundwater. Reduced groundwater in Horton Bluff sandstone typically contains elevated concentrations of Fe 2+ and Mn 2+ , whereas groundwater containing high concentrations of U is found primary in oxidizing environments in quartz arenite sandstone units in the Wolfville Formation. Consumption of groundwater in the Grand Pré region may pose a health risk; however, the level of risk remains unknown. This study emphasizes that in the area of Grand Pré, water that is considered aesthetically undesirable (containing high Fe and Mn) may pose less of a health risk (low U) than waters that are aesthetically pleasing.Des niveaux élevés d’uranium qui dépassent les concentrations maximales admises ont été détectés dans certains échantillons d’eau de puits en Nouvelle Écosse. Dans cette étude, nous examinons les effets de la réduction-oxydation et de la géologie régionale sur la mobilité de l’uranium dans l’eau souterraine de la région de Grand Pré, dans l’extrémité est de la vallée d’Annapolis-Cornwallis, dans le sud ouest de la Nouvelle Écosse. Le site étudié repose sur du schiste charbonneux et du grès arkosique de la Formation de Horton Bluff, du Mississippien tardif, et sur du grès arénacé de la Formation de Wolfville, du Trias. Les échantillons d’eau de puits creusés ont été analysés sur place pour ce qui est de divers paramètres de qualité de l’eau (pH, conductivité, température, oxygène dissous) et des analyses ont eu lieu en laboratoire pour établir l’alcalinité et les concentrations de cations (72) et de principaux anions (9). Plusieurs échantillons dépassaient les limites permises par Santé Canada (2011), en ce qui concerne la teneur en uranium (20 μg/L), certaines teneurs ayant atteint 50,8 μg/L. Il en allait de même en ce qui concerne les critères esthétiques pour le fer (des teneurs ayant atteint 605 μg/L), le manganèse (des teneurs ayant atteint 2,28 mg/L) et d’autres cations. Les données indiquent que divers phénomènes de réduction-oxydation surviennent dans le secteur étudié. Le contexte géospatial des données chimiques porte à croire que la lithologie de la couche aquifère sous jacente exerce une forte influence sur la disponibilité de l’uranium dans l’eau souterraine. L’eau souterraine qui a subi une réduction dans le grès de Horton Bluff contient généralement des concentrations élevées de Fe 2+ et de Mn 2+ , tandis que l’eau souterraine à forte concentration d’uranium est surtout observée dans les milieux oxydants de grès de quartz-arénite de la Formation de Wolfville. La consommation de l’eau souterraine dans la région de Grand Pré peut poser un risque pour la santé, mais le degré de risque demeure inconnu. Cette étude met en lumière le risque moindre pour la santé (faible teneur en U) de l’eau dans la région de Grand Pré, qui a une apparence pouvant laisse à désirer (elle a une forte teneur en Fe et en Mn), comparativement à d’autres sources d’eau d’apparence plus agréable. [Traduit par la redaction