Understanding former heroin users' experience of change: An interpretative phenomenological analysis

This study aimed to explore the experiences of those who have been involved in change from problematic heroin use and how they have made sense out of their experiences.Seven participants, who had been abstinent from heroin for a minimum of two years were interviewed about their experience of change. Practicing drug workers were chosen who had previously used heroin and were now employed to support individuals who were still using drugs. In this way they represented former drug users who had made significant long-term change.Interviews were analysed using Interpretative Phenomenological Analysis (IPA). Three superordinate themes were identified, which were, ‘Making sense of change’, ‘Identity, Relationships and Lifestyle’ and ‘Internal Distress’. A number of subthemes were also identified for each superordinate theme.Implications for substance misuse and Counselling Psychology included increasing awareness of the complexity and factors involved in change and appreciating change from former heroin users’ perspectives. This challenged current and more popularly-held perspectives consistent with political and organisational agendas which focus upon costs associated with heroin use.Factors such as a change of mind-set, identification of avoidance behaviours to manage emotional pain and distress and finding alternative ways of managing pain may also apply to other forms of change, such as other forms of addictions and weight loss.Implications for Counselling Psychology included a consideration of self-transformation and the factors which may initiate behavioural change and the importance of appreciating ongoing aspects of change including identity, relationships and lifestyle

Chemical and isotopic characteristics of weathering and nitrogen release in non-glacial drainage waters on Arctic tundra

Soil–water interactions in coastal tundra soils are a potential source of nutrients for surrounding fjordal and coastal ecosystems. Changes in water chemistry and stable isotope composition from three streams in west Spitsbergen were examined to assess the sources and losses of nitrogen, sulfur and carbon in thin organic tundra soils overlying sediments. Studies were undertaken from snowmelt (mid June) through to the end of the summer (September) in both 2001 and 2002. Drainage water chemistry was dominated by the solution of Ca–Mg carbonates with δ13C values in the waters being uncharacteristically high (approx. −2‰ at the end of the season), reflecting a largely open system in which the CO2 is derived equally from the atmosphere and plant/soil sources. Early melt waters had δ34S values dominated by sea salt reflecting the close proximity to the ocean. However, as the season progressed the marine influence lessened. Extrapolation of the data suggests that the origin of non-sea salt δ34S was the oxidation of reduced sulfur from coal particles in the subsoil. Concentrations of inorganic N in stream waters were generally very low. However, values were found to increase as the season progressed, possibly through increased microbial activity in the soil and the early senescence of tundra plants reducing demand. Dual isotope analysis of δ15N and δ18O suggested that the vast majority of snow-pack was assimilated by the soil microbial biomass before being released, recycled and lost to drainage waters. Organic N concentrations in drainage waters were generally equal to or greater than losses of inorganic N from tundra soils. The study demonstrated the effectiveness of stable isotope data for understanding biogeochemical cycling and soil–water interactions in tundra ecosystems. The implications of the results are discussed in relation to climate warming

The sensitivity of cosmogenic radionuclide analysis to soil bulk density: implications for soil formation rates

Improving our knowledge of soil formation is critical so that we can better understand the first‐order controls on soil thickness and more effectively inform land‐management decisions. Cosmogenic radionuclide analysis has allowed soil scientists to more accurately constrain the rates at which soils form from bedrock. In such analysis, the concentration of an isotope, such as Beryllium‐10, is measured from a sample of bedrock. Because this concentration is partly governed by the lowering of the bedrock‐soil interface, a cosmogenic depth‐profile model can be fitted to infer the bedrock and surface lowering rates compatible with the measured concentrations. Given that the bedrock‐soil interface is shielded by soil, the cosmic rays responsible for the in‐situ production of the radionuclide are attenuated, with attenuation rates dependent on the density profile of this soil. Many studies have assumed that soil bulk density is either equal to that of the bedrock or constant with depth. The failure to acknowledge the variations in soil bulk density means that cosmogenically derived soil formation rates previously published may be under‐ or overestimates. Here, we deploy a new model called “CoSOILcal” to a global compilation of cosmogenic analyses of soil formation and, by making use of estimated bulk density profiles, recalculate rates of soil formation to assess the sensitivity to this important parameter. We found that where a soil mantle >0.25 m overlies the soil‐bedrock interface, accounting for the soil bulk density profile brings about a significantly slower rate of soil formation than that previously published. Moreover, the impact of using bulk density profiles on cosmogenically derived soil formation rates increases as soil thickens. These findings call into question the accuracy of our existing soil formation knowledge and we suggest that future cosmogenic radionuclide analysis must consider the bulk density profile of the overlying soil

The Sensitivity of Cosmogenic Radionuclide Analysis to Soil Bulk Density:Implications for Soil Formation Rates

Improving our knowledge of soil formation is critical so that we can better understand the first-order controls on soil thickness and more effectively inform land-management decisions. Cosmogenic radionuclide analysis has allowed soil scientists to more accurately constrain the rates at which soils form from bedrock. In such analysis, the concentration of an isotope, such as Beryllium-10, is measured from a sample of bedrock. Because this concentration is partly governed by the lowering of the bedrock-soil interface, a cosmogenic depth-profile model can be fitted to infer the bedrock and surface lowering rates compatible with the measured concentrations. Given that the bedrock-soil interface is shielded by soil, the cosmic rays responsible for the in-situ production of the radionuclide are attenuated, with attenuation rates dependent on the density profile of this soil. Many studies have assumed that soil bulk density is either equal to that of the bedrock or constant with depth. The failure to acknowledge the variations in soil bulk density means that cosmogenically derived soil formation rates previously published may be under- or overestimates. Here, we deploy a new model called "CoSOILcal" to a global compilation of cosmogenic analyses of soil formation and, by making use of estimated bulk density profiles, recalculate rates of soil formation to assess the sensitivity to this important parameter. We found that where a soil mantle >0.25 m overlies the soil-bedrock interface, accounting for the soil bulk density profile brings about a significantly slower rate of soil formation than that previously published. Moreover, the impact of using bulk density profiles on cosmogenically derived soil formation rates increases as soil thickens. These findings call into question the accuracy of our existing soil formation knowledge and we suggest that future cosmogenic radionuclide analysis must consider the bulk density profile of the overlying soil. Highlights The effect of heterogeneities in soil bulk density on cosmogenically derived soil formation rates is unknown. Soil formation rates are recalculated using a new model to analyse the effect of density variations. Accounting for density in soils >0.25 m thickness brings about significantly slower soil formation rates. Measuring soil bulk density is essential when cosmogenically deriving soil formation rates

Carbon sequestration in the soils of Northern Ireland: potential based on mineralogical controls

Complex relationships between soil organic carbon (SOC), mineralogy, land-use and climate may exist in the soils of Northern Ireland. Greater understanding of these interactions can improve the effectiveness of SOC sequestration and management strategies. Mineralogy and SOC concentrations in soils derived from four different parent rocks (sandstone, shale, basalt and granodiorite) were characterised and indicate that soil mineralogy and geochemistry play an important role in determining the concentration of SOC. This primarily depended on the absence or presence of high surface area clay and iron oxide minerals and on the soil pH. Soil mineralogy did not appear to have a major impact on the composition of soil organic matter (SOM) with depth. The results suggest that when carbon sequestration practices in Northern Ireland are considered, soils derived from basalts are likely to acquire greater carbon concentrations than soils from other lithologie

Exploring a string-like landscape

We explore inflationary trajectories within randomly-generated two-dimensional potentials, considered as a toy model of the string landscape. Both the background and perturbation equations are solved numerically, the latter using the two-field formalism of Peterson and Tegmark which fully incorporates the effect of isocurvature perturbations. Sufficient inflation is a rare event, occurring for only roughly one in $10^5$ potentials. For models generating sufficient inflation, we find that the majority of runs satisfy current constraints from WMAP. The scalar spectral index is less than 1 in all runs. The tensor-to-scalar ratio is below the current limit, while typically large enough to be detected by next-generation CMB experiments and perhaps also by Planck. In many cases the inflationary consistency equation is broken by the effect of isocurvature modes.Comment: 24 pages with 8 figures incorporated, matches version accepted by JCA

Soil natural capital in Europe; a framework for state and change assessment

Soils underpin our existence through food production and represent the largest terrestrial carbon store. Understanding soil state-and-change in response to climate and land use change is a major challenge. Our aim is to bridge the science-policy interface by developing a natural capital accounting structure for soil, for example, attempting a mass balance between soil erosion and production, which indicates that barren land, and woody crop areas are most vulnerable to potential soil loss. We test out our approach using earth observation, modelling and ground based sample data from the European Union’s Land Use/Cover Area frame statistical Survey (LUCAS) soil monitoring program. Using land cover change data for 2000–2012 we are able to identify land covers susceptible to change, and the soil resources most at risk. Tree covered soils are associated with the highest carbon stocks, and are on the increase, while areas of arable crops are declining, but artificial surfaces are increasing. The framework developed offers a substantial step forward, demonstrating the development of biophysical soil accounts that can be used in wider socio-economic and policy assessment; initiating the development of an integrated soil monitoring approach called for by the United Nations Intergovernmental Technical Panel on Soils

Distribution and speciation of phosphorus in foreshore sediments of the Thames estuary, UK

Estuarine sediments can be a source of Phosphorus (P) to coastal waters, contributing to nutrient budgets and geochemical cycles. In this work, the concentration and speciation of P in 47 cores were examined from the inter-tidal mud flats of the tidal river Thames (~ 120 km). Results of P concentration and speciation were combined with published data relating to known sediment dynamics and water chemistry (salinity) within the estuary to produce a conceptual model of sediment-P behaviour. Results demonstrated significant P desorption occurring after sediment passed through the Estuarine Turbidity Maximum and when the salinity of the river water exceeded ~ 6 ppt. It was found that organic P was desorbed to a greater extent than inorganic P in the lower estuary. Models were used to identify those geochemical parameters that contributed to the Total P (R2 = 0.80), oxalate extractable P (R2 = 0.80) and inorganic P (R2 = 0.76) concentrations within the Thames estuary

A comparison of characterisation and modelling approaches to predict dissolved metal concentrations in soils

Environmental contextIt is useful to know the concentration of ‘labile’, or chemically active, metal in soils because it can be used to predict metal solubility and environmental impact. Several methods for extracting the labile metal from soils have been proposed, and here we have tested two of these to see how well the resulting data can be used to model metal solubility. Such mixed approaches can be applied to different soil types with the potential to model metal solubility over large areas.RationalePredicting terrestrial metal dynamics requires modelling of metal solubility in soils. Here, we test the ability of two geochemical speciation models that differ in complexity and data requirements (WHAM/Model VII and POSSMs), to predict metal solubility across a broad range of soil properties, using differing estimates of the labile soil metal concentration.MethodologyUsing a dataset of UK soils, we characterised basic properties including pH and the concentrations of humic substances, mineral oxides and metals. We estimated labile metal by extraction with 0.05 mol L−1 Na2H2EDTA and by multi-element isotopic dilution (E-value). Dissolved concentrations of Ni, Cu, Zn, Cd and Pb were estimated in 0.01 mol L−1 Ca(NO3)2 soil suspensions using the total metal ({M}total), the EDTA-extracted pool ({M}EDTA) and the E-value ({M}E) as alternative estimates of the chemically reactive metal concentration.ResultsConcentrations of {M}EDTA were highly correlated with values of {M}E, although some systematic overestimation was seen. Both WHAM/Model VII and POSSMs provided reasonable predictions when {M}EDTA or {M}E were used as input. WHAM/Model VII predictions were improved by fixing soil humic acid to a constant proportion of the soil organic matter, instead of the measured humic and fulvic acid concentrations.DiscussionThis work provides further evidence for the usefulness of speciation modelling for predicting soil metal solubility, and for the usefulness of EDTA-extracted metal as a surrogate for the labile metal pool. Predictions may be improved by more robust characterisation of the soil and porewater humic substance content and quality