Evaluating the use of multi-element soil analysis in archaeology: a study of a postmedieval croft (Olligarth) in Shetland

Multi-element soil analysis is an established technique in archaeology, but there has been little work to understand the processes and loadings involved. The abandoned farm (croft) of Olligarth, Shetland provided the opportunity of validating the technique by sampling from known contexts. The results showed multi-element soil analysis could accurately differentiate between areas of known function. Accuracy was increased using samples from the floor layers rather than topsoils. The elements that produced the best discriminant model of function were P, Ca, Cr, V, Fe, Nd, Ti, Pb, Al, and Yb. However because of cross-correlation between elements, Cu, Zn, Sr, Ba, K, Mg, Mn, Na, Ni, Co, Ni, and the rare earth elements, were also important potential discriminators. Of these P, Ca, Zn, Sr, Pb, Cu, Ba, Na, K, and Nd correlated positively with soil CEC and organic matter content and may, in part, originate from fuel materials, plasters, dung and bone. Ti, Cr, Al and many rare earth elements were influenced by local geological variation and are of less interest archaeologically

Nighttime chemistry at a high altitude site above Hong Kong

Nighttime reactions of nitrogen oxides influence ozone, volatile organic compounds, and aerosol and are thus important to the understanding of regional air quality. Despite large emissions and rapid recent growth of nitrogen oxide concentrations, there are few studies of nighttime chemistry in China. Here we present measurements of nighttime nitrogen oxides, NO3 and N2O5, from a coastal mountaintop site in Hong Kong adjacent to the megacities of the Pearl River Delta region. This is the first study of nighttime chemistry from a site within the residual layer in China. Key findings include the following. First, highly concentrated urban NOx outflow from the Pearl River Delta region was sampled infrequently at night, with N2O5 mixing ratios up to 8 ppbv (1 min average) or 12 ppbv (1 s average) in nighttime aged air masses. Second, the average N2O5 uptake coefficient was determined from a best fit to the available steady state lifetime data as γ(N2O5) = 0.014 ± 0.007. Although this determination is uncertain due to the difficulty of separating N2O5 losses from those of NO3, this value is in the range of previous residual layer determinations of N2O5 uptake coefficients in polluted air in North America. Third, there was a significant contribution of biogenic hydrocarbons to NO3 loss inferred from canister samples taken during daytime. Finally, daytime N2O5 mixing ratios were in accord with their predicted photochemical steady state. Heterogeneous uptake of N2O5 in fog is determined to be an important production mechanism for soluble nitrate, even during daytime. Key Points Large (up to 12 ppbv N2O5) but infrequent nocturnal NOx outflow from the Pearl River Delta Average N2O5 uptake coefficients 0.014 ± 0.007, in line with residual layer measurements in the U.S. Daytime N2O5 follows predicted steady state but rapidly produces soluble nitrate in fog.Department of Civil and Environmental Engineerin

Observations of nitryl chloride and modeling its source and effect on ozone in the planetary boundary layer of southern China

Nitryl chloride (ClNO2) plays potentially important roles in atmospheric chemistry, but its abundance and effect are not fully understood due to the small number of ambient observations of ClNO2 to date. In late autumn 2013, ClNO2 was measured with a chemical ionization mass spectrometer (CIMS) at a mountain top (957 m above sea level) in Hong Kong. During 12 nights with continuous CIMS data, elevated mixing ratios of ClNO2 (>400 parts per trillion by volume) or its precursor N2O5 (>1000 pptv) were observed on six nights, with the highest ever reported ClNO2 (4.7 ppbv, 1 min average) and N2O5 (7.7 ppbv, 1 min average) in one case. Backward particle dispersion calculations driven by winds simulated with a mesoscale meteorological model show that the ClNO2/N2O5-laden air at the high-elevation site was due to transport of urban/industrial pollution north of the site. The highest ClNO2/N2O5 case was observed in a later period of the night and was characterized with extensively processed air and with the presence of nonoceanic chloride. A chemical box model with detailed chlorine chemistry was used to assess the possible impact of the ClNO2 in the well-processed regional plume on next day ozone, as the air mass continued to downwind locations. The results show that the ClNO2 could enhance ozone by 5-16% at the ozone peak or 11-41% daytime ozone production in the following day. This study highlights varying importance of the ClNO2 chemistry in polluted environments and the need to consider this process in photochemical models for prediction of ground-level ozone and haze. Key Points First observation of ClNO2 in the planetary boundary layer of China Combined high-resolution meteorological and measurement-constrained chemical models in data analysis ClNO2 enhances daytime ozone peak by 5-16% in well-processed PRD air.Department of Civil and Environmental Engineerin

Tell formation processes as indicated from geoarchaeological and geochemical investigations at Xeropolis, Euboea, Greece

Xeropolis is a tell site on the island of Euboea, Greece just to the east of the village of Lefkandi, and was occupied from the Early Bronze Age to the Early Iron Age. Excavations in recent years have provided an opportunity to investigate site formation processes using geoarchaeological and geochemical techniques. Sediments derived from the tell on the southern side have been lost by coastal erosion whilst those on the north mantle the flanking slope. Of particular interest is a homogeneous and unstratified deposit of over 2 m which overlies the archaeology near the southern perimeter of the summit area. The soil structure as evident in thin sections indicates a high degree of bioturbation, probably stimulated by recent manuring and cultivation. The implication is that tillage erosion has had a major impact on the morphology as well as on the surface soils of the tell. Despite such reworking and redeposition of near surface materials, it is still possible from multi-element analysis to identify the geochemical distinctiveness of six archaeological contexts (pit, house, plaster floor, alley, road and yard); pits and floors have high loadings of all elements except Pb; in contrast pits and floors have the lowest elemental concentrations

A longitudinal study of closed head injury : neuropsychological outcome and structural analysis using region of interest measurements and voxel-based morphometry

Background: The hippocampus and corpus callosum have been shown to be vulnerable in head injury. Various neuroimaging modalities and quantitative measurement techniques have been employed to investigate pathological changes in these structures. Cognitive and behavioural deficiencies have also been well documented in head injury. Aims: The aim of this research project was to investigate structural changes in the hippocampus and corpus callosum. Two different quantitative methods were used to measure physical changes and neuropsychological assessment was performed to determine cognitive and behavioural deficit. It was also intended to investigate the relationship between structural change and neuropsychology at 1 and 6 months post injury. Method: Forty-seven patients with head injury (ranging from mild to severe) had undergone a battery of neuropsychological tests and an MRI scan at 1 and 6 months post injury. T1-weighted MRI scans were obtained and analysis of hippocampus and corpus callosum was performed using region-of-interest techniques and voxel-based morphometry which also included comparison to 18 healthy volunteers. The patients completed neuropsychological assessment at 1 and 6 months post injury and data obtained was analysed with respect to each assessment and with structural data to determine cognitive decline and correlation with neuroanatomy. Results: Voxel-based morphometry illustrated reduced whole scan signal differences between patients and controls and changes in patients between 1 and 6 months post injury. Reduced grey matter concentration was also found using voxel-based morphometry and segmented images between patients and controls. A number of neuropsychological aspects were related to injury severity and correlations with neuroanatomy were present. Voxel-based morphometry provided a greater number of associations than region-of-interest analysis. No longitudinal changes were found in the hippocampus or corpus callosum using region-of-interest methodology or voxel-based morphometry. Conclusions: Decreased grey matter concentration identified with voxel-based morphometry illustrated that structural deficit was present in the head injured patients and does not change between 1 and 6 months. Voxel-based morphometry appears more sensitive for detecting structural changes after head injury than region- of-interest methods. Although the majority of patients had suffered mild head injury, cognitive and neurobehavioural deficits were evidenced by a substantial number of patients reporting increased anxiety and depression levels. Also, the findings of relationships between reduced grey matter concentration and cognitive test scores are indicative of the effects of diffuse brain damage in the patient group.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A longitudinal study of closed head injury : neuropsychological outcome and structural analysis using region of interest measurements and voxel-based morphometry

Background: The hippocampus and corpus callosum have been shown to be vulnerable in head injury. Various neuroimaging modalities and quantitative measurement techniques have been employed to investigate pathological changes in these structures. Cognitive and behavioural deficiencies have also been well documented in head injury. Aims: The aim of this research project was to investigate structural changes in the hippocampus and corpus callosum. Two different quantitative methods were used to measure physical changes and neuropsychological assessment was performed to determine cognitive and behavioural deficit. It was also intended to investigate the relationship between structural change and neuropsychology at 1 and 6 months post injury. Method: Forty-seven patients with head injury (ranging from mild to severe) had undergone a battery of neuropsychological tests and an MRI scan at 1 and 6 months post injury. T1-weighted MRI scans were obtained and analysis of hippocampus and corpus callosum was performed using region-of-interest techniques and voxel-based morphometry which also included comparison to 18 healthy volunteers. The patients completed neuropsychological assessment at 1 and 6 months post injury and data obtained was analysed with respect to each assessment and with structural data to determine cognitive decline and correlation with neuroanatomy. Results: Voxel-based morphometry illustrated reduced whole scan signal differences between patients and controls and changes in patients between 1 and 6 months post injury. Reduced grey matter concentration was also found using voxel-based morphometry and segmented images between patients and controls. A number of neuropsychological aspects were related to injury severity and correlations with neuroanatomy were present. Voxel-based morphometry provided a greater number of associations than region-of-interest analysis. No longitudinal changes were found in the hippocampus or corpus callosum using region-of-interest methodology or voxel-based morphometry. Conclusions: Decreased grey matter concentration identified with voxel-based morphometry illustrated that structural deficit was present in the head injured patients and does not change between 1 and 6 months. Voxel-based morphometry appears more sensitive for detecting structural changes after head injury than region- of-interest methods. Although the majority of patients had suffered mild head injury, cognitive and neurobehavioural deficits were evidenced by a substantial number of patients reporting increased anxiety and depression levels. Also, the findings of relationships between reduced grey matter concentration and cognitive test scores are indicative of the effects of diffuse brain damage in the patient group.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Exploring the Local Milky Way: M Dwarfs as Tracers of Galactic Populations

We have assembled a spectroscopic sample of low-mass dwarfs observed as part of the Sloan Digital Sky Survey along one Galactic sightline, designed to investigate the observable properties of the thin and thick disks. This sample of ~7400 K and M stars also has measured ugriz photometry, proper motions, and radial velocities. We have computed UVW space motion distributions, and investigate their structure with respect to vertical distance from the Galactic Plane. We place constraints on the velocity dispersions of the thin and thick disks, using two-component Gaussian fits. We also compare these kinematic distributions to a leading Galactic model. Finally, we investigate other possible observable differences between the thin and thick disks, such as color, active fraction and metallicity.Comment: 11 pages, 12 figures, Accepted by A

Multi-element soil analysis: an assessment of its potential as an aid to archaeological interpretation

Multi-element soil analysis is now an established technique in archaeology. It has been used to locate archaeological sites and define the extent of human activity beyond the structural remains, and to aid interpretation of space use in and around archaeological remains. This study aimed to evaluate the consistency of these soil element signatures between sites and hence their potential usefulness in archaeological studies. Known contexts on abandoned farms across the UK were sampled to test the relationships between element concentrations and known functional area and to assess inter-site variability. The results clearly show that there are significant differences in the soil chemistry of contrasting functional areas, particularly for Ba, Ca, P, Zn, Cu, Sr and Pb. Despite significant site specific effects, which appear to reflect individual anthropogenic practices rather than geological influences, there is sufficient similarity in the pattern of element enhancement to allow reliable interpretation of former function using discriminant models. Relating these enhancements to precise soil inputs, however, is more problematic because many important soil inputs do not contain distinct element fingerprints and because there is mixing of materials within the soil. There is also a suggestion that charcoal and bone play an important role in both the loading and post-depositional retention of Ca, Sr, P, Zn, and Cu and thus may be significant in the formation of soil element concentration patterns

Numerical properties of staggered quarks with a taste-dependent mass term

The numerical properties of staggered Dirac operators with a taste-dependent mass term proposed by Adams [1,2] and by Hoelbling [3] are compared with those of ordinary staggered and Wilson Dirac operators. In the free limit and on (quenched) interacting configurations, we consider their topological properties, their spectrum, and the resulting pion mass. Although we also consider the spectral structure, topological properties, locality, and computational cost of an overlap operator with a staggered kernel, we call attention to the possibility of using the Adams and Hoelbling operators without the overlap construction. In particular, the Hoelbling operator could be used to simulate two degenerate flavors without additive mass renormalization, and thus without fine-tuning in the chiral limit.Comment: 14 pages, 9 figures. V2: published version; important note added regarding Hoelbling fermions, otherwise minor change

FiberGLAST: a scintillating fiber approach to the GLAST mission

FiberGLAST is a scintillating fiber gamma-ray detector designed for the GLAST mission. The system described below provides superior effective area and field of view for modest cost and risk. An overview of the FiberGLAST instrument is presented, as well as a more detailed description of the principle elements of the primary detector volume. The triggering and readout electronics are described, and Monte Carlo Simulations of the instrument performance are presented