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Item does not contain fulltext, The Triarchic Psychopathy Measure (TriPM) is based on a 3-dimensional conceptual model, though few studies have directly tested a 3-factor structure. The current study used a large community sample (N = 1,064, 53% males, Mage = 34) to test the structure of the TriPM via exploratory and confirmatory factor analysis, along with 4 community replication samples from North American and Europe (Ns = 511-603, 33-49% males) and 1 European male offender sample (N = 150). Three of these samples were also used to model the correlations between relevant external correlates and the original TriPM factors versus emergent factors to examine the cost of misspecifying TriPM structure. The model analyses did not support a 3-factor model (comparative fit index = .76, root mean square error of approximation = .08), revealing a number of items with limited statistical information, but uncovered a 7-factor structure (comparative fit index = .92, root mean square error of approximation = .04). From the majority of Boldness, Meanness, and Disinhibition scale items, respectively, emerged 3 factors reflecting Positive Self-Image, Leadership, and Stress Immunity; 2 factors tapping Callousness and Enjoy Hurting; and 2 factors involving Trait Impulsivity and Overt Antisociality. Further, the Enjoy Hurting and Overt Antisociality factors were more strongly correlated with one another than with the other scales from their home domains (Callousness and Impulsivity). All 7 emergent factors were differentially associated with the external correlates, suggesting that the 3 original TriPM factors do not optimally represent the conceptual model underlying the TriPM.

Item does not contain fulltext, We respond to a critique by Patrick et al. (2020) of our recent study (Roy et al., 2020) that raised questions regarding the three-factor model of the Triarchic Psychopathy Measure (TriPM). Roy et al. demonstrated that a replicable model involving seven unidimensional factors accounted for the TriPM items across North American and European general population samples, as well as European male offenders. Despite having access to large TriPM datasets, the Patrick et al. critique relied on tangential analyses of general personality traits, using a single college sample with TriPM data as supplemental. Thus, Patrick et al. ignored findings highlighting multidimensional TriPM scales and the uncertainty they introduce with respect to the larger nomological network of psychopathy. In our reply, we demonstrate additional problems with the three-factor TriPM model and show that the seven-factor model out-performs the three-factor model in predicting correlates of psychopathy.

Item does not contain fulltext, The Triarchic Psychopathy Measure (TriPM) is based on a 3-dimensional conceptual model, though few studies have directly tested a 3-factor structure. The current study used a large community sample (N = 1,064, 53% males, Mage = 34) to test the structure of the TriPM via exploratory and confirmatory factor analysis, along with 4 community replication samples from North American and Europe (Ns = 511-603, 33-49% males) and 1 European male offender sample (N = 150). Three of these samples were also used to model the correlations between relevant external correlates and the original TriPM factors versus emergent factors to examine the cost of misspecifying TriPM structure. The model analyses did not support a 3-factor model (comparative fit index = .76, root mean square error of approximation = .08), revealing a number of items with limited statistical information, but uncovered a 7-factor structure (comparative fit index = .92, root mean square error of approximation = .04). From the majority of Boldness, Meanness, and Disinhibition scale items, respectively, emerged 3 factors reflecting Positive Self-Image, Leadership, and Stress Immunity; 2 factors tapping Callousness and Enjoy Hurting; and 2 factors involving Trait Impulsivity and Overt Antisociality. Further, the Enjoy Hurting and Overt Antisociality factors were more strongly correlated with one another than with the other scales from their home domains (Callousness and Impulsivity). All 7 emergent factors were differentially associated with the external correlates, suggesting that the 3 original TriPM factors do not optimally represent the conceptual model underlying the TriPM.

Item does not contain fulltext, We respond to a critique by Patrick et al. (2020) of our recent study (Roy et al., 2020) that raised questions regarding the three-factor model of the Triarchic Psychopathy Measure (TriPM). Roy et al. demonstrated that a replicable model involving seven unidimensional factors accounted for the TriPM items across North American and European general population samples, as well as European male offenders. Despite having access to large TriPM datasets, the Patrick et al. critique relied on tangential analyses of general personality traits, using a single college sample with TriPM data as supplemental. Thus, Patrick et al. ignored findings highlighting multidimensional TriPM scales and the uncertainty they introduce with respect to the larger nomological network of psychopathy. In our reply, we demonstrate additional problems with the three-factor TriPM model and show that the seven-factor model out-performs the three-factor model in predicting correlates of psychopathy.

Item does not contain fulltext, We respond to a critique by Patrick et al. (2020) of our recent study (Roy et al., 2020) that raised questions regarding the three-factor model of the Triarchic Psychopathy Measure (TriPM). Roy et al. demonstrated that a replicable model involving seven unidimensional factors accounted for the TriPM items across North American and European general population samples, as well as European male offenders. Despite having access to large TriPM datasets, the Patrick et al. critique relied on tangential analyses of general personality traits, using a single college sample with TriPM data as supplemental. Thus, Patrick et al. ignored findings highlighting multidimensional TriPM scales and the uncertainty they introduce with respect to the larger nomological network of psychopathy. In our reply, we demonstrate additional problems with the three-factor TriPM model and show that the seven-factor model out-performs the three-factor model in predicting correlates of psychopathy.

Item does not contain fulltext, The Triarchic Psychopathy Measure (TriPM) is based on a 3-dimensional conceptual model, though few studies have directly tested a 3-factor structure. The current study used a large community sample (N = 1,064, 53% males, Mage = 34) to test the structure of the TriPM via exploratory and confirmatory factor analysis, along with 4 community replication samples from North American and Europe (Ns = 511-603, 33-49% males) and 1 European male offender sample (N = 150). Three of these samples were also used to model the correlations between relevant external correlates and the original TriPM factors versus emergent factors to examine the cost of misspecifying TriPM structure. The model analyses did not support a 3-factor model (comparative fit index = .76, root mean square error of approximation = .08), revealing a number of items with limited statistical information, but uncovered a 7-factor structure (comparative fit index = .92, root mean square error of approximation = .04). From the majority of Boldness, Meanness, and Disinhibition scale items, respectively, emerged 3 factors reflecting Positive Self-Image, Leadership, and Stress Immunity; 2 factors tapping Callousness and Enjoy Hurting; and 2 factors involving Trait Impulsivity and Overt Antisociality. Further, the Enjoy Hurting and Overt Antisociality factors were more strongly correlated with one another than with the other scales from their home domains (Callousness and Impulsivity). All 7 emergent factors were differentially associated with the external correlates, suggesting that the 3 original TriPM factors do not optimally represent the conceptual model underlying the TriPM.

Theoretical metal recovery/gangue rejection curves, which establish the maximum gravity separation efficiency, can be determined from 3D image analysis by high resolution X-ray microtomography (HRXMT). Tomographic data from two Australian sulphidic ores (a copper-gold ore and a free-milling gold ore) were used in 3D image analysis to obtain recovery v separation density curves for the gold minerals and rejection v separation density curves for the gangue minerals. Grain size distributions for the sulphide minerals were also obtained to describe particle texture and explain the theoretical recovery/rejection curves. For the Cu-Au ore it was found that a maximum gangue rejection of around 90% can be expected for a gravity separation at 2.75 g/cc, with a corresponding expected maximum recovery of about 57% for pyrite and 72% for chalcopyrite. A maximum gangue rejection of just 56% could be expected for the same gravity separation for the free-milling sample. Maximum recovery of pyrite and chalcopyrite for this sample, however, would be over 90%. The theoretical density-gangue rejection results were found to be similar to experimental dense media cyclone separation results, and the DMC recovery of sulphide minerals was just less than the theoretical maximum recovery expected from the HRXMT analysis., Theoretical metal recovery/gangue rejection curves, which establish the maximum gravity separation efficiency, can be determined from 3D image analysis by high resolution X-ray microtomography (HRXMT). Tomographic data from two Australian sulphidic ores (a copper-gold ore and a free-milling gold ore) were used in 3D image analysis to obtain recovery v separation density curves for the gold minerals and rejection v separation density curves for the gangue minerals. Grain size distributions for the sulphide minerals were also obtained to describe particle texture and explain the theoretical recovery/rejection curves. For the Cu-Au ore it was found that a maximum gangue rejection of around 90% can be expected for a gravity separation at 2.75 g/cc, with a corresponding expected maximum recovery of about 57% for pyrite and 72% for chalcopyrite. A maximum gangue rejection of just 56% could be expected for the same gravity separation for the free-milling sample. Maximum recovery of pyrite and chalcopyrite for this sample, however, would be over 90%. The theoretical density-gangue rejection results were found to be similar to experimental dense media cyclone separation results, and the DMC recovery of sulphide minerals was just less than the theoretical maximum recovery expected from the HRXMT analysis.

Fungal endophytes are sources of novel bioactive compounds but relatively few agriculturally important fruiting plants harboring endophytes have been carefully studied. Previously, we identified a griseofulvin-producing Xylaria species isolated from Vaccinium angustifolium, V. corymbosum, and Pinus strobus. Morphological and genomic analysis determined that it was a new species, described here as Xylaria ellisii. Untargeted high-resolution LC-MS metabolomic analysis of the extracted filtrates and mycelium from 15 blueberry isolates of this endophyte revealed differences in their metabolite profiles. Toxicity screening of the extracts sho

Hydrocarbon (i.e. oil) extraction, transport, consumption, and pollution occur daily in marine environments, threatening vulnerable natural resources, habitats, and biodiversity. However, threats of episodic oil spills to imperiled marine species are not as well-studied as more acute, readily apparent threats such as incidental capture in fisheries and habitat degradation. We performed a global review of spill incident databases to evaluate reported effects of oil spills on sea turtles, which are flagship species of the world’s oceans. Our goals were to (1) summarize available information about oil spills and their effects on sea turtles; (2) identify major knowledge gaps; and (3) provide recommendations related to oil spills and sea turtles for managers, researchers, and conservation groups around the world. Over 2000 oil spill incidents of variable magnitude (range: ~20 to >1 million barrels) have occurred worldwide in the past 60 yr in areas where sea turtles are found, but resulting effects on sea turtles have been reported in less than 2% of those incidents. Further, evidence indicates that most effects are related to heavy external oiling, while chemical effects of oil exposure have not been well defined. We recommend that, where available, resources be prioritized to document co-occurrence of turtles and oil, the degree and nature of oil exposure, and mortality and reproductive losses to individual sea turtles and their populations caused by spills and spill response activities. These data will best inform assessments of the extent and magnitude of adverse effects of oil spills on sea turtles.

Hydrocarbon (i.e. oil) extraction, transport, consumption, and pollution occur daily in marine environments, threatening vulnerable natural resources, habitats, and biodiversity. However, threats of episodic oil spills to imperiled marine species are not as well-studied as more acute, readily apparent threats such as incidental capture in fisheries and habitat degradation. We performed a global review of spill incident databases to evaluate reported effects of oil spills on sea turtles, which are flagship species of the world’s oceans. Our goals were to (1) summarize available information about oil spills and their effects on sea turtles; (2) identify major knowledge gaps; and (3) provide recommendations related to oil spills and sea turtles for managers, researchers, and conservation groups around the world. Over 2000 oil spill incidents of variable magnitude (range: ~20 to >1 million barrels) have occurred worldwide in the past 60 yr in areas where sea turtles are found, but resulting effects on sea turtles have been reported in less than 2% of those incidents. Further, evidence indicates that most effects are related to heavy external oiling, while chemical effects of oil exposure have not been well defined. We recommend that, where available, resources be prioritized to document co-occurrence of turtles and oil, the degree and nature of oil exposure, and mortality and reproductive losses to individual sea turtles and their populations caused by spills and spill response activities. These data will best inform assessments of the extent and magnitude of adverse effects of oil spills on sea turtles.

Design flood estimates are often required for small, heavily urbanised catchments, which respond quickly to storm events. However, hydrological models are most frequently calibrated using daily or hourly data on larger, more rural catchments, which respond on much longer timescales. Here, we calibrate a lumped, conceptual rainfall‐runoff model (ReFH2) in three small (2–6 km2), heavily urbanised catchments in Swindon, UK, assessing the benefits of using high‐resolution temporal and spatial data. Modelling shows that heavy urbanisation does not by itself invalidate the applicability of a lumped, conceptual model. However, we find great dissimilarities between runoff behaviour in different heavily urbanised catchments, with some types behaving similarly to rural catchments. In other cases, response and contributing catchment area can depend more on underground topology than catchment topography. Calibrated runoff response is insensitive to the temporal resolution of the calibration events in all study catchments. Future research should aim to differentiate between different types of heavily urbanised catchment, potentially through landscape metrics to measure the connectivity and isolation of different land surface types.

Design flood estimates are often required for small, heavily urbanised catchments, which respond quickly to storm events. However, hydrological models are most frequently calibrated using daily or hourly data on larger, more rural catchments, which respond on much longer timescales. Here, we calibrate a lumped, conceptual rainfall‐runoff model (ReFH2) in three small (2–6 km2), heavily urbanised catchments in Swindon, UK, assessing the benefits of using high‐resolution temporal and spatial data. Modelling shows that heavy urbanisation does not by itself invalidate the applicability of a lumped, conceptual model. However, we find great dissimilarities between runoff behaviour in different heavily urbanised catchments, with some types behaving similarly to rural catchments. In other cases, response and contributing catchment area can depend more on underground topology than catchment topography. Calibrated runoff response is insensitive to the temporal resolution of the calibration events in all study catchments. Future research should aim to differentiate between different types of heavily urbanised catchment, potentially through landscape metrics to measure the connectivity and isolation of different land surface types.

Item does not contain fulltext, Considerable evidence implicates cellular senescence in the biology of aging and chronic disease. Diet and exercise are determinants of healthy aging; however, the extent to which they affect the behavior and accretion of senescent cells within distinct tissues is not clear. Here we tested the hypothesis that exercise prevents premature senescent cell accumulation and systemic metabolic dysfunction induced by a fast-food diet (FFD). Using transgenic mice that express EGFP in response to activation of the senescence-associated p16(INK4a) promoter, we demonstrate that FFD consumption causes deleterious changes in body weight and composition as well as in measures of physical, cardiac, and metabolic health. The harmful effects of the FFD were associated with dramatic increases in several markers of senescence, including p16, EGFP, senescence-associated beta-galactosidase, and the senescence-associated secretory phenotype (SASP) specifically in visceral adipose tissue. We show that exercise prevents the accumulation of senescent cells and the expression of the SASP while nullifying the damaging effects of the FFD on parameters of health. We also demonstrate that exercise initiated after long-term FFD feeding reduces senescent phenotype markers in visceral adipose tissue while attenuating physical impairments, suggesting that exercise may provide restorative benefit by mitigating accrued senescent burden. These findings highlight a novel mechanism by which exercise mediates its beneficial effects and reinforces the effect of modifiable lifestyle choices on health span.

Item does not contain fulltext, Cellular senescence, a stress-induced irreversible growth arrest often characterized by expression of p16(Ink4a) (encoded by the Ink4a/Arf locus, also known as Cdkn2a) and a distinctive secretory phenotype, prevents the proliferation of preneoplastic cells and has beneficial roles in tissue remodelling during embryogenesis and wound healing. Senescent cells accumulate in various tissues and organs over time, and have been speculated to have a role in ageing. To explore the physiological relevance and consequences of naturally occurring senescent cells, here we use a previously established transgene, INK-ATTAC, to induce apoptosis in p16(Ink4a)-expressing cells of wild-type mice by injection of AP20187 twice a week starting at one year of age. We show that compared to vehicle alone, AP20187 treatment extended median lifespan in both male and female mice of two distinct genetic backgrounds. The clearance of p16(Ink4a)-positive cells delayed tumorigenesis and attenuated age-related deterioration of several organs without apparent side effects, including kidney, heart and fat, where clearance preserved the functionality of glomeruli, cardio-protective KATP channels and adipocytes, respectively. Thus, p16(Ink4a)-positive cells that accumulate during adulthood negatively influence lifespan and promote age-dependent changes in several organs, and their therapeutic removal may be an attractive approach to extend healthy lifespan.

Item does not contain fulltext, Considerable evidence implicates cellular senescence in the biology of aging and chronic disease. Diet and exercise are determinants of healthy aging; however, the extent to which they affect the behavior and accretion of senescent cells within distinct tissues is not clear. Here we tested the hypothesis that exercise prevents premature senescent cell accumulation and systemic metabolic dysfunction induced by a fast-food diet (FFD). Using transgenic mice that express EGFP in response to activation of the senescence-associated p16(INK4a) promoter, we demonstrate that FFD consumption causes deleterious changes in body weight and composition as well as in measures of physical, cardiac, and metabolic health. The harmful effects of the FFD were associated with dramatic increases in several markers of senescence, including p16, EGFP, senescence-associated beta-galactosidase, and the senescence-associated secretory phenotype (SASP) specifically in visceral adipose tissue. We show that exercise prevents the accumulation of senescent cells and the expression of the SASP while nullifying the damaging effects of the FFD on parameters of health. We also demonstrate that exercise initiated after long-term FFD feeding reduces senescent phenotype markers in visceral adipose tissue while attenuating physical impairments, suggesting that exercise may provide restorative benefit by mitigating accrued senescent burden. These findings highlight a novel mechanism by which exercise mediates its beneficial effects and reinforces the effect of modifiable lifestyle choices on health span.

Item does not contain fulltext, Cellular senescence, a stress-induced irreversible growth arrest often characterized by expression of p16(Ink4a) (encoded by the Ink4a/Arf locus, also known as Cdkn2a) and a distinctive secretory phenotype, prevents the proliferation of preneoplastic cells and has beneficial roles in tissue remodelling during embryogenesis and wound healing. Senescent cells accumulate in various tissues and organs over time, and have been speculated to have a role in ageing. To explore the physiological relevance and consequences of naturally occurring senescent cells, here we use a previously established transgene, INK-ATTAC, to induce apoptosis in p16(Ink4a)-expressing cells of wild-type mice by injection of AP20187 twice a week starting at one year of age. We show that compared to vehicle alone, AP20187 treatment extended median lifespan in both male and female mice of two distinct genetic backgrounds. The clearance of p16(Ink4a)-positive cells delayed tumorigenesis and attenuated age-related deterioration of several organs without apparent side effects, including kidney, heart and fat, where clearance preserved the functionality of glomeruli, cardio-protective KATP channels and adipocytes, respectively. Thus, p16(Ink4a)-positive cells that accumulate during adulthood negatively influence lifespan and promote age-dependent changes in several organs, and their therapeutic removal may be an attractive approach to extend healthy lifespan.

Item does not contain fulltext, Cellular senescence, a stress-induced irreversible growth arrest often characterized by expression of p16(Ink4a) (encoded by the Ink4a/Arf locus, also known as Cdkn2a) and a distinctive secretory phenotype, prevents the proliferation of preneoplastic cells and has beneficial roles in tissue remodelling during embryogenesis and wound healing. Senescent cells accumulate in various tissues and organs over time, and have been speculated to have a role in ageing. To explore the physiological relevance and consequences of naturally occurring senescent cells, here we use a previously established transgene, INK-ATTAC, to induce apoptosis in p16(Ink4a)-expressing cells of wild-type mice by injection of AP20187 twice a week starting at one year of age. We show that compared to vehicle alone, AP20187 treatment extended median lifespan in both male and female mice of two distinct genetic backgrounds. The clearance of p16(Ink4a)-positive cells delayed tumorigenesis and attenuated age-related deterioration of several organs without apparent side effects, including kidney, heart and fat, where clearance preserved the functionality of glomeruli, cardio-protective KATP channels and adipocytes, respectively. Thus, p16(Ink4a)-positive cells that accumulate during adulthood negatively influence lifespan and promote age-dependent changes in several organs, and their therapeutic removal may be an attractive approach to extend healthy lifespan.

This study investigates whether long-term changes in observed series of high flows can be attributed to changes in land use via nonstationary flood-frequency analyses. A point process characterization of threshold exceedances is used, which allows for direct inclusion of covariates in the model; as well as a nonstationary model for block maxima series. In particular, changes in annual, winter, and summer block maxima and peaks over threshold extracted from gauged instantaneous flows records in two hydrologically similar catchments located in proximity to one another in northern England are investigated. The study catchment is characterized by large increases in urbanization levels in recent decades, while the paired control catchment has remained undeveloped during the study period (1970–2010). To avoid the potential confounding effect of natural variability, a covariate which summarizes key climatological properties is included in the flood-frequency model. A significant effect of the increasing urbanization levels on high flows is detected, in particular in the summer season. Point process models appear to be superior to block maxima models in their ability to detect the effect of the increase in urbanization levels on high flows.

This study investigates whether long-term changes in observed series of high flows can be attributed to changes in land use via nonstationary flood-frequency analyses. A point process characterization of threshold exceedances is used, which allows for direct inclusion of covariates in the model; as well as a nonstationary model for block maxima series. In particular, changes in annual, winter, and summer block maxima and peaks over threshold extracted from gauged instantaneous flows records in two hydrologically similar catchments located in proximity to one another in northern England are investigated. The study catchment is characterized by large increases in urbanization levels in recent decades, while the paired control catchment has remained undeveloped during the study period (1970–2010). To avoid the potential confounding effect of natural variability, a covariate which summarizes key climatological properties is included in the flood-frequency model. A significant effect of the increasing urbanization levels on high flows is detected, in particular in the summer season. Point process models appear to be superior to block maxima models in their ability to detect the effect of the increase in urbanization levels on high flows.

The effect of urban land cover on catchment flood response is evaluated using a lumped rainfall–runoff model to analyse flood events from selected UK catchments with mixed urban and rural land use. The present study proposes and evaluates a series of three extensions to an existing model to enable a better representation of urban effects, namely: an increase in runoff volume, reduced response time and a decrease in baseflow (resulting from decreased infiltration). Based on observed flood events from seven catchments, cross-validation methods are used to compare the predictive ability of the model variants with that of the original unmodified model. The results show that inclusion of urban effects increases the predictive ability of the model across catchments, despite large between-event variability of model performance. More detailed investigations into the relationship between model performance and individual event characteristics (antecedent soil moisture, rainfall duration, depth and intensity) did not reveal systematic inabilities of the model to reproduce certain types of events. Finally, it is demonstrated that the new extended model has the ability to simulate urban effects in accordance with the expected changes in storm runoff patterns.

In November 2009, record-breaking rainfall resulted in severe, damaging flooding in Cumbria, in the north-west of England. This paper presents an analysis of the river flows and lake levels experienced during the event. Comparison with previous maxima shows the exceptional nature of this event, with new maximum flows being established at 17 river flow gauging stations, particularly on catchments influenced by lakes. The return periods of the flood peaks are estimated using the latest Flood Estimation Handbook statistical procedures. Results demonstrate that the event has considerably reduced estimates of flood frequency and associated uncertainty. Analysis of lake levels suggests that their record high levels reduced their attenuating effect, significantly affecting the timing and magnitude of downstream peaks. The peak flow estimate of 700 m3s-1 at Workington, the lowest station on the Derwent, was examined in the context of upstream inputs and was found to be plausible. The results of this study have important implications for the future development of flood frequency estimation methods for the UK. It is recommended that further research is undertaken on the role of abnormally elevated lake levels and that flood frequency estimation procedures in lake-influenced catchments are reviewed.

The effect of urban land cover on catchment flood response is evaluated using a lumped rainfall–runoff model to analyse flood events from selected UK catchments with mixed urban and rural land use. The present study proposes and evaluates a series of three extensions to an existing model to enable a better representation of urban effects, namely: an increase in runoff volume, reduced response time and a decrease in baseflow (resulting from decreased infiltration). Based on observed flood events from seven catchments, cross-validation methods are used to compare the predictive ability of the model variants with that of the original unmodified model. The results show that inclusion of urban effects increases the predictive ability of the model across catchments, despite large between-event variability of model performance. More detailed investigations into the relationship between model performance and individual event characteristics (antecedent soil moisture, rainfall duration, depth and intensity) did not reveal systematic inabilities of the model to reproduce certain types of events. Finally, it is demonstrated that the new extended model has the ability to simulate urban effects in accordance with the expected changes in storm runoff patterns.

In November 2009, record-breaking rainfall resulted in severe, damaging flooding in Cumbria, in the north-west of England. This paper presents an analysis of the river flows and lake levels experienced during the event. Comparison with previous maxima shows the exceptional nature of this event, with new maximum flows being established at 17 river flow gauging stations, particularly on catchments influenced by lakes. The return periods of the flood peaks are estimated using the latest Flood Estimation Handbook statistical procedures. Results demonstrate that the event has considerably reduced estimates of flood frequency and associated uncertainty. Analysis of lake levels suggests that their record high levels reduced their attenuating effect, significantly affecting the timing and magnitude of downstream peaks. The peak flow estimate of 700 m3s-1 at Workington, the lowest station on the Derwent, was examined in the context of upstream inputs and was found to be plausible. The results of this study have important implications for the future development of flood frequency estimation methods for the UK. It is recommended that further research is undertaken on the role of abnormally elevated lake levels and that flood frequency estimation procedures in lake-influenced catchments are reviewed.

Rising temperatures and changing precipitation patterns across the Hindu Kush–Himalaya (HKH) region resulting from climate change have an influence on water resource availability and food security for the downstream population. This review seeks to objectively assess the available evidence of the impacts of climate change on glacier hydrology and the wider implications upon water resources within the Indus, Ganges, and Brahmaputra basins. Glacier meltwater contribution to river flows is scale dependent and varies considerably across the east–west climatic zones of the HKH. For the Ganges and Brahmaputra this contribution is estimated to be significantly less than for the Indus to the west, with summer monsoon rains dominating flows from central and easterly areas, whereas meltwater remains a significant contributor to downstream flow of westerly basins, which receive most precipitation during winter. No corroborated trends exist in observed discharge for any basin, and such analyses are hindered by a lack of good-quality long-term data. Predicted increases in temperature will drive increased shrinkage of glaciers, leading to initial increases in meltwater produced, followed by subsequent declines with reduced glacier mass. The impacts of such changes are predicted to be minimal for the overall discharge of the Ganges and Brahmaputra, where increases in rainfall may in fact lead to increased flows but with greater variability. Within the Indus basin, reduced meltwater will have significant impacts upon available runoff; however, increased uncertainties surrounding precipitation and socioeconomic changes limit any conclusive assessment of how water availability will be affected; moreover, seasonality of runoff may be a more important factor. Scientific challenges and research recommendations are identified for the region. This review proposes the need for the scientific evidence pertaining to the region's glacier systems to be approached objectively in the future, suc

A high resolution X-ray micro CT (HRXMT) system with a voxel resolution of less than 1 micron has been used for the characterisation of particle damage during the HPGR crushing of a copper sulphide ore. The HRXMT analysis of the crushed particles showed that during comminution the damage state of particles increases, cracks become wider, cracks penetrate deeper inside the particles, and the number of cracks within each particle increases. The increase in damage with increase in HPGR pressure accounts for the observed decrease in work index at higher pressures., 10 refs., A high resolution X-ray micro CT (HRXMT) system with a voxel resolution of less than 1 micron has been used for the characterisation of particle damage during the HPGR crushing of a copper sulphide ore. The HRXMT analysis of the crushed particles showed that during comminution the damage state of particles increases, cracks become wider, cracks penetrate deeper inside the particles, and the number of cracks within each particle increases. The increase in damage with increase in HPGR pressure accounts for the observed decrease in work index at higher pressures.

X-ray micro-and nano-tomography (CT) provide for quantitative mineral exposure/liberation analysis of multiphase particle populations in 3D. In the case of micro-CT, analysis of more than 30 000 particles, 100 microns in size, can now be accomplished nondestructively in less than 5 hours at 2 micron voxel resolution with little sample preparation. The voxel resolution can be extended to 50 nanometers using nano-CT. In this way liberation-limited grade/recovery curves can be established from the analysis of feed material and used by the process engineer to evaluate separation efficiency. In addition, particle texture of concentrate and tailings products can be examined to see if this textural characteristic can explain the deportment of locked particles. In the case of low-grade feed material, as in the case of precious metals at the ppm level, mineral phase isolation and identification can be accomplished with an appropriate protocol by radiography using projections to identify particles of interest quickly. Within minutes it may be possible to examine more than 1 000 000 particles and to isolate mineral phases present at the ppm level for further tomographic interrogation or examination in polished section., X-ray micro-and nano-tomography (CT) provide for quantitative mineral exposure/liberation analysis of multiphase particle populations in 3D. In the case of micro-CT, analysis of more than 30 000 particles, 100 microns in size, can now be accomplished nondestructively in less than 5 hours at 2 micron voxel resolution with little sample preparation. The voxel resolution can be extended to 50 nanometers using nano-CT. In this way liberation-limited grade/recovery curves can be established from the analysis of feed material and used by the process engineer to evaluate separation efficiency. In addition, particle texture of concentrate and tailings products can be examined to see if this textural characteristic can explain the deportment of locked particles. In the case of low-grade feed material, as in the case of precious metals at the ppm level, mineral phase isolation and identification can be accomplished with an appropriate protocol by radiography using projections to identify particles of interest quickly. Within minutes it may be possible to examine more than 1 000 000 particles and to isolate mineral phases present at the ppm level for further tomographic interrogation or examination in polished section.

In November 2009, prolonged heavy rainfall brought extensive flooding to many parts of the western UK and Ireland, with the worst flooding concentrated in west Cumbria in north-west England. For two of the most affected catchments, the Derwent and the Leven, this paper presents an analysis of the rainfall, river flows and lake levels, including a comparison with other recent flood events. Spatial analysis of rainfall illustrates that the return period of flood peaks in these catchments is influenced not just by the return period of the causative catchment average rainfall, but also by its spatial distribution and intensity – particularly in a catchment less dominated by a large lake system. A combined assessment of rarity in terms of both rainfall and flows demonstrates the extreme nature of the November 2009 event and the complexity of the re-lationship between the estimated return periods of catchment average rainfall and peak flow.

In November 2009, prolonged heavy rainfall brought extensive flooding to many parts of the western UK and Ireland, with the worst flooding concentrated in west Cumbria in north-west England. For two of the most affected catchments, the Derwent and the Leven, this paper presents an analysis of the rainfall, river flows and lake levels, including a comparison with other recent flood events. Spatial analysis of rainfall illustrates that the return period of flood peaks in these catchments is influenced not just by the return period of the causative catchment average rainfall, but also by its spatial distribution and intensity – particularly in a catchment less dominated by a large lake system. A combined assessment of rarity in terms of both rainfall and flows demonstrates the extreme nature of the November 2009 event and the complexity of the re-lationship between the estimated return periods of catchment average rainfall and peak flow.

The importance is discussed of the rheological properties of concentrated clay mineral suspensions such as kaolinite in ceramics, paper and pulp, drilling muds and in filtration and dewatering. The surface chemistry and rheology of kaolinite particles is complicated by the non-uniform surface charge densities on the edge surfaces and basal silica and alumina faces. Electrophoretic measurements do not provide the required information about the surface charge or potential, so an approach based on the surface charge densities of the silica and alumina faces and the edge surface was developed to provide information on interparticle spacing and the role of pair-wise interactions in controlling the rheology of the suspensions. The maximum shear yield stress of the suspension indicates the significant role played by particle orientation as driven by edge-edge, edge-face and face-face interaction energies. The energies obtained using the DVLO theory define the different interactions and explain the pH dependence of the shear yield stress., The importance is discussed of the rheological properties of concentrated clay mineral suspensions such as kaolinite in ceramics, paper and pulp, drilling muds and in filtration and dewatering. The surface chemistry and rheology of kaolinite particles is complicated by the non-uniform surface charge densities on the edge surfaces and basal silica and alumina faces. Electrophoretic measurements do not provide the required information about the surface charge or potential, so an approach based on the surface charge densities of the silica and alumina faces and the edge surface was developed to provide information on interparticle spacing and the role of pair-wise interactions in controlling the rheology of the suspensions. The maximum shear yield stress of the suspension indicates the significant role played by particle orientation as driven by edge-edge, edge-face and face-face interaction energies. The energies obtained using the DVLO theory define the different interactions and explain the pH dependence of the shear yield stress.

As part of studies of metabolites from fungi common in the built environment in Canadian homes, we investigated metabolites from strains of three Eurotium species, namely E. herbariorum, E. amstelodami, and E. rubrum as well as a number of isolates provisionally identified as Aspergillus ustus. The latter have been recently assigned as the new species A. insuetus and A. calidoustus. E. amstelodami produced neoechinulin A and neoechinulin B, epiheveadride, flavoglaucin, auroglaucin, and isotetrahydroauroglaucin as major metabolites. Minor metabolites included echinulin, preechinulin and neoechinulin E. E. rubrum produced all of these metabolites, but epiheveadride was detected as a minor metabolite. E. herbariorum produced cladosporin as a major metabolite, in addition to those found in E. amstelodami. This species also produced questin and neoechinulin E as minor metabolites. This is the first report of epiheveadride occurring as a natural product, and the first nonadride isolated from Eurotium species. Unlike strains from mainly infection-related samples, largely from Europe, neither ophiobolins G and H nor austins were detected in the Canadian strains of A. insuetus and A. calidoustus tested, all of which had been reported from the latter species. TMC-120 A, B, C and a sesquiterpene drimane are reported with certainty for the first time from indoor isolates, as well as two novel related methyl isoquinoline alkaloids., As part of studies of metabolites from fungi common in the built environment in Canadian homes, we investigated metabolites from strains of three Eurotium species, namely E. herbariorum, E. amstelodami, and E. rubrum as well as a number of isolates provisionally identified as Aspergillus ustus. The latter have been recently assigned as the new species A. insuetus and A. calidoustus. E. amstelodami produced neoechinulin A and neoechinulin B, epiheveadride, flavoglaucin, auroglaucin, and isotetrahydroauroglaucin as major metabolites. Minor metabolites included echinulin, preechinulin and neoechinulin E. E. rubrum produced all of these metabolites, but epiheveadride was detected as a minor metabolite. E. herbariorum produced cladosporin as a major metabolite, in addition to those found in E. amstelodami. This species also produced questin and neoechinulin E as minor metabolites. This is the first report of epiheveadride occurring as a natural product, and the first nonadride isolated from Eurotium species. Unlike strains from mainly infection-related samples, largely from Europe, neither ophiobolins G and H nor austins were detected in the Canadian strains of A. insuetus and A. calidoustus tested, all of which had been reported from the latter species. TMC-120 A, B, C and a sesquiterpene drimane are reported with certainty for the first time from indoor isolates, as well as two novel related methyl isoquinoline alkaloids.

As part of studies of metabolites from fungi common in the built environment in Canadian homes, we investigated metabolites from strains of three Eurotium species, namely E. herbariorum, E. amstelodami, and E. rubrum as well as a number of isolates provisionally identified as Aspergillus ustus. The latter have been recently assigned as the new species A. insuetus and A. calidoustus. E. amstelodami produced neoechinulin A and neoechinulin B, epiheveadride, flavoglaucin, auroglaucin, and isotetrahydroauroglaucin as major metabolites. Minor metabolites included echinulin, preechinulin and neoechinulin E. E. rubrum produced all of these metabolites, but epiheveadride was detected as a minor metabolite. E. herbariorum produced cladosporin as a major metabolite, in addition to those found in E. amstelodami. This species also produced questin and neoechinulin E as minor metabolites. This is the first report of epiheveadride occurring as a natural product, and the first nonadride isolated from Eurotium species. Unlike strains from mainly infection-related samples, largely from Europe, neither ophiobolins G and H nor austins were detected in the Canadian strains of A. insuetus and A. calidoustus tested, all of which had been reported from the latter species. TMC-120 A, B, C and a sesquiterpene drimane are reported with certainty for the first time from indoor isolates, as well as two novel related methyl isoquinoline alkaloids., As part of studies of metabolites from fungi common in the built environment in Canadian homes, we investigated metabolites from strains of three Eurotium species, namely E. herbariorum, E. amstelodami, and E. rubrum as well as a number of isolates provisionally identified as Aspergillus ustus. The latter have been recently assigned as the new species A. insuetus and A. calidoustus. E. amstelodami produced neoechinulin A and neoechinulin B, epiheveadride, flavoglaucin, auroglaucin, and isotetrahydroauroglaucin as major metabolites. Minor metabolites included echinulin, preechinulin and neoechinulin E. E. rubrum produced all of these metabolites, but epiheveadride was detected as a minor metabolite. E. herbariorum produced cladosporin as a major metabolite, in addition to those found in E. amstelodami. This species also produced questin and neoechinulin E as minor metabolites. This is the first report of epiheveadride occurring as a natural product, and the first nonadride isolated from Eurotium species. Unlike strains from mainly infection-related samples, largely from Europe, neither ophiobolins G and H nor austins were detected in the Canadian strains of A. insuetus and A. calidoustus tested, all of which had been reported from the latter species. TMC-120 A, B, C and a sesquiterpene drimane are reported with certainty for the first time from indoor isolates, as well as two novel related methyl isoquinoline alkaloids.

To understand better the adsorption state of collectors on KCl, captive bubble contact-angle measurements were made at KCl and NaCl crystal surfaces in their saturated solutions. Various collectors were investigated at a range of concentrations. The results show that both cationic and anionic collectors produce a hydrophobic state at the structure-breaking KCl salt surface, with finite contact-angle values of between 30 and 40 degrees, whereas the contact angle at the structure- making NaCl surface is zero at all collector concentrations, suggesting that no collector adsorption occurs, an inference supported by results from molecular dynamics simulation. It is suggested that the presence of surface defects promotes adsorption at the KCl surface, and that flotation occurs as a result of bubble attachment at the edges or corners of KCl particles with the formation of aeroflocs., To understand better the adsorption state of collectors on KCl, captive bubble contact-angle measurements were made at KCl and NaCl crystal surfaces in their saturated solutions. Various collectors were investigated at a range of concentrations. The results show that both cationic and anionic collectors produce a hydrophobic state at the structure-breaking KCl salt surface, with finite contact-angle values of between 30 and 40 degrees, whereas the contact angle at the structure- making NaCl surface is zero at all collector concentrations, suggesting that no collector adsorption occurs, an inference supported by results from molecular dynamics simulation. It is suggested that the presence of surface defects promotes adsorption at the KCl surface, and that flotation occurs as a result of bubble attachment at the edges or corners of KCl particles with the formation of aeroflocs.

The use was investigated of C(12)-trithiocarbonate (C(12)-TTC) collector as a partial replacement for a dithiocarbonate (DTC)/dithiophosphate (DTP) combination. The results showed a significant improvement in the rejection of gangue and in the flotation kinetics, grade and recovery of PGMs. In a pilot-plant trial, a 5 mole% replacement of the DTC/DTP combination by C(12)-TTC resulted in the replacement of large opaque bubbles with small clear ones. A similar flotation response was obtained using only one-third of the depressant dosage. In a preliminary plant trial on underground UG2 ore, the initial rougher concentrates were characterised by higher PGM concentrate grades, in part due to improved chromite rejection. The concentrate produced from the TTC trial also exhibited a much finer particle size distribution. The overall circuit performance, including secondary regrind and flotation, showed an increase in concentrate grade of about 44% while the tailings grade remained unchanged., The use was investigated of C(12)-trithiocarbonate (C(12)-TTC) collector as a partial replacement for a dithiocarbonate (DTC)/dithiophosphate (DTP) combination. The results showed a significant improvement in the rejection of gangue and in the flotation kinetics, grade and recovery of PGMs. In a pilot-plant trial, a 5 mole% replacement of the DTC/DTP combination by C(12)-TTC resulted in the replacement of large opaque bubbles with small clear ones. A similar flotation response was obtained using only one-third of the depressant dosage. In a preliminary plant trial on underground UG2 ore, the initial rougher concentrates were characterised by higher PGM concentrate grades, in part due to improved chromite rejection. The concentrate produced from the TTC trial also exhibited a much finer particle size distribution. The overall circuit performance, including secondary regrind and flotation, showed an increase in concentrate grade of about 44% while the tailings grade remained unchanged.

The use is discussed of thiourea as an alternative to cyanide for Au extraction from different auriferous mineral resources. Recent research results show that thiourea decomposition is quite slow in the presence of ferric sulphate for simple solutions. Ferric sulphate and formamidine disulphide are effective oxidants with fast kinetics. No passivation of the Au surface is observed in simple acidic solutions. However, in actual leaching systems, some sulphide minerals significantly catalyse the redox reaction between thiourea and ferric ion, causing high thiourea consumption if ferric ion is present in excess. The presence of Cu has a deleterious influence on this leaching system., The use is discussed of thiourea as an alternative to cyanide for Au extraction from different auriferous mineral resources. Recent research results show that thiourea decomposition is quite slow in the presence of ferric sulphate for simple solutions. Ferric sulphate and formamidine disulphide are effective oxidants with fast kinetics. No passivation of the Au surface is observed in simple acidic solutions. However, in actual leaching systems, some sulphide minerals significantly catalyse the redox reaction between thiourea and ferric ion, causing high thiourea consumption if ferric ion is present in excess. The presence of Cu has a deleterious influence on this leaching system.

The flotation of soluble salt is discussed, with particular reference to carbonate salts such as those associated with the trona deposit of the Green River basin, Wyoming. The equilibrium and dynamic surface tensions of sodium carbonate and sodium bicarbonate salts were measured as a function of the salt concentration up to saturation and compared with model predictions using the Gibbs-Langmuir adsorption theory. The results showed that negative adsorption of sodium carbonate leads to a significant increase in surface tension of the brine solution. The negative adsorption and the increase in surface tension are significantly lower for sodium bicarbonate compared with sodium carbonate. Sodium ions are significantly more hydrated than carbonate and bicarbonate ions, and tend to be excluded from the air-brine interface while carbonate and bicarbonate ions are accommodated at the interface. The balance between sodium exclusion and carbonate/bicarbonate accommodation results in an increase in the surface tension of these solutions, with an increase in salt concentration., The flotation of soluble salt is discussed, with particular reference to carbonate salts such as those associated with the trona deposit of the Green River basin, Wyoming. The equilibrium and dynamic surface tensions of sodium carbonate and sodium bicarbonate salts were measured as a function of the salt concentration up to saturation and compared with model predictions using the Gibbs-Langmuir adsorption theory. The results showed that negative adsorption of sodium carbonate leads to a significant increase in surface tension of the brine solution. The negative adsorption and the increase in surface tension are significantly lower for sodium bicarbonate compared with sodium carbonate. Sodium ions are significantly more hydrated than carbonate and bicarbonate ions, and tend to be excluded from the air-brine interface while carbonate and bicarbonate ions are accommodated at the interface. The balance between sodium exclusion and carbonate/bicarbonate accommodation results in an increase in the surface tension of these solutions, with an increase in salt concentration.

A model based on the approach of Hsih, Wen and Kuan (1995) was evaluated experimentally to describe the extent of grain exposure as a function of particle size, using 3D analysis of the crushed ore particles by cone beam X-ray microtomography. Three composites were used: rhyolite/sulphide, andesite/sulphide and andesite/oxide, each with grain size distributions representing the various particle size classes of an ore crushed for heap leaching. The results suggested that the extent of preferential grain boundary breakage varies both with ore type and with particle size for a given ore type., A model based on the approach of Hsih, Wen and Kuan (1995) was evaluated experimentally to describe the extent of grain exposure as a function of particle size, using 3D analysis of the crushed ore particles by cone beam X-ray microtomography. Three composites were used: rhyolite/sulphide, andesite/sulphide and andesite/oxide, each with grain size distributions representing the various particle size classes of an ore crushed for heap leaching. The results suggested that the extent of preferential grain boundary breakage varies both with ore type and with particle size for a given ore type.

Systems including thiosulphate, thiocyanate and thiourea have been studied as alternative gold lixiviants, prompted by environmental concerns over cyanide and problems with refractory ores. These thiosystems have some chemical similarities, allowing Au leaching in a practical oxidising environment, but their solution chemistry is complicated by thioreagent instability and the many other reactions that occur during Au leaching. Interference reactions of selected metal ions and sulphide minerals are therefore examined in order to understand important aspects of the solution chemistry that control the stability of the thioleaching reactions. Applications of thioreagents as lixiviants for oxide and refractory gold ores are presented. Most common sulphide minerals in refractory ores, such as Cu and Fe sulphides, become unstable in the alkaline copper-ammonia-thiosulphate system, while in acidic environments thiocyanate is an effective lixiviant offering much greater stability against oxidation decomposition than thiourea, which suffers from both high reagent consumption and passivation of the gold surface by elemental sulphur ferric and cupric systems., Systems including thiosulphate, thiocyanate and thiourea have been studied as alternative gold lixiviants, prompted by environmental concerns over cyanide and problems with refractory ores. These thiosystems have some chemical similarities, allowing Au leaching in a practical oxidising environment, but their solution chemistry is complicated by thioreagent instability and the many other reactions that occur during Au leaching. Interference reactions of selected metal ions and sulphide minerals are therefore examined in order to understand important aspects of the solution chemistry that control the stability of the thioleaching reactions. Applications of thioreagents as lixiviants for oxide and refractory gold ores are presented. Most common sulphide minerals in refractory ores, such as Cu and Fe sulphides, become unstable in the alkaline copper-ammonia-thiosulphate system, while in acidic environments thiocyanate is an effective lixiviant offering much greater stability against oxidation decomposition than thiourea, which suffers from both high reagent consumption and passivation of the gold surface by elemental sulphur ferric and cupric systems.

The original air-sparged hydrocyclone design used porous sintered steel or porous polyethylene tubes as spargers. To diminish/prevent plugging and to reduce pressure loss in the gas path, a wire screen sparger and new hydrocyclone design have been developed, allowing wide application of the technology in solving environmental problems and as a chemical reactor. Field and laboratory trials have shown that the technology might be preferred for stripping volatile compounds from contaminated water; it has also been developed for absorption of SO2 and toluene vapours and for the recovery of cyanide., The original air-sparged hydrocyclone design used porous sintered steel or porous polyethylene tubes as spargers. To diminish/prevent plugging and to reduce pressure loss in the gas path, a wire screen sparger and new hydrocyclone design have been developed, allowing wide application of the technology in solving environmental problems and as a chemical reactor. Field and laboratory trials have shown that the technology might be preferred for stripping volatile compounds from contaminated water; it has also been developed for absorption of SO2 and toluene vapours and for the recovery of cyanide.

Spherical calcium dioleate particles 1-10 micrometres in diameter were used as atomic force microscope (AFM) probes to measure interaction forces between the collector colloid and calcite and fluorite surfaces. The attractive AFM force between the calcium dioleate spheres and the fluorite surface is strong and has longer range than that predicted by the Deljaguin-Landau-Verwey-Overbeek (DLVO) theory. The repulsive AFM force between the calcium dioleate spheres and the fluorite surface is not in agreement with the DLVO prediction. The results are explained in relation to non-DLVO forces, including the attractive hydrophobic force and the repulsive hydration force. The non-DLVO interactions were confirmed by the different interfacial water structures at fluorite/ and calcite/water interfaces as shown by numerical computation results using molecular dynamics simulation., Spherical calcium dioleate particles 1-10 micrometres in diameter were used as atomic force microscope (AFM) probes to measure interaction forces between the collector colloid and calcite and fluorite surfaces. The attractive AFM force between the calcium dioleate spheres and the fluorite surface is strong and has longer range than that predicted by the Deljaguin-Landau-Verwey-Overbeek (DLVO) theory. The repulsive AFM force between the calcium dioleate spheres and the fluorite surface is not in agreement with the DLVO prediction. The results are explained in relation to non-DLVO forces, including the attractive hydrophobic force and the repulsive hydration force. The non-DLVO interactions were confirmed by the different interfacial water structures at fluorite/ and calcite/water interfaces as shown by numerical computation results using molecular dynamics simulation.

The N2TEC flotation technology is currently being used for the recovery of auriferous pyrite at Newmont's Lone Tree Plant, Nevada. Initially the system operated satisfactorily, but cyanide in the flotation mill water appeared to be responsible for a loss in pyrite recovery. This was confirmed by laboratory experiments, and a programme was initiated to study flotation chemistry variables by electrochemically controlled contact-angle measurements. The results showed that activation of pyrite in such cyanide solutions can be achieved more effectively with Pb than with Cu. Significant improvement at the plant was subsequently achieved using Pb activation and the recovery increased to expected levels. In addition to pyrite depression by residual cyanide, the effect of the activator is significant in relation to collector (potassium amyl xanthate) consumption and the creation of a low-potential, low pH hydrophobic pyrite surface., The N2TEC flotation technology is currently being used for the recovery of auriferous pyrite at Newmont's Lone Tree Plant, Nevada. Initially the system operated satisfactorily, but cyanide in the flotation mill water appeared to be responsible for a loss in pyrite recovery. This was confirmed by laboratory experiments, and a programme was initiated to study flotation chemistry variables by electrochemically controlled contact-angle measurements. The results showed that activation of pyrite in such cyanide solutions can be achieved more effectively with Pb than with Cu. Significant improvement at the plant was subsequently achieved using Pb activation and the recovery increased to expected levels. In addition to pyrite depression by residual cyanide, the effect of the activator is significant in relation to collector (potassium amyl xanthate) consumption and the creation of a low-potential, low pH hydrophobic pyrite surface.

The interfacial water structure and hydration states of soluble salt surfaces, together with the precipitation tendency of the corresponding collector salts, is of considerable importance in explaining their flotation behaviour. Soluble salts can be classified into structure-makers that facilitate hydrogen bonding between water molecules and structure-breakers that disrupt it. Studies of collector adsorption and interfacial water structure in soluble salt flotation systems are important for cost-effective production of soda ash from trona resources. A flotation procedure has been developed for trona from the Green River Basin in Wyoming, where 14 500 000 tons were mined in 2003. Results from laboratory research show that run-of-mine trona ore can be treated at ambient temperature and pressure using a special flotation procedure to separate the gangue minerals. A trona concentrate of 99% purity is obtained with recovery of 97%., The interfacial water structure and hydration states of soluble salt surfaces, together with the precipitation tendency of the corresponding collector salts, is of considerable importance in explaining their flotation behaviour. Soluble salts can be classified into structure-makers that facilitate hydrogen bonding between water molecules and structure-breakers that disrupt it. Studies of collector adsorption and interfacial water structure in soluble salt flotation systems are important for cost-effective production of soda ash from trona resources. A flotation procedure has been developed for trona from the Green River Basin in Wyoming, where 14 500 000 tons were mined in 2003. Results from laboratory research show that run-of-mine trona ore can be treated at ambient temperature and pressure using a special flotation procedure to separate the gangue minerals. A trona concentrate of 99% purity is obtained with recovery of 97%.