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This study compared the ability of various intracanal restorative materials to restore the stiffness of endodontically treated teeth. We randomly placed bovine central incisors into six groups. We did not instrument negative control teeth, and we instrumented, but did not restore, positive control teeth. We restored teeth in the experimental groups with resin-based composite, resin-based composite plus a fiberglass post, or resin-based composite plus a cemented metal post. We subjected all teeth to nondestructive, compressive testing and recorded the stiffness of each sample. Results indicated that performing endodontic access and instrumentation alone resulted in a 24% loss in tooth stiffness. Teeth restored using an intracanal resin bonding technique alone or in combination with a post regained the stiffness lost from access and instrumentation, and teeth that were restored with bonded resin and a metal post cemented with Panavia 21 cement were significantly stiffer than the untreated negative control group (p < 0.05). Our results suggest that intracanal resin bonding techniques may reduce the need for immediate crown placement after endodontic therapy. [ABSTRACT FROM AUTHOR]

Background: The longer-term risks of statins on physical function among people with HIV are unclear., Methods: Longitudinal analysis of Multicenter AIDS Cohort Study men between 40 and 75 years of age with ≥2 measures of gait speed or grip strength. Generalized estimating equations with interaction terms between (1) statin use and age and (2) HIV serostatus, age, and statin use were considered to evaluate associations between statin use and physical function. Models were adjusted for demographics and cardiovascular risk factors., Results: Among 2021 men (1048 with HIV), baseline median age was 52 (interquartile range 46-58) years; 636 were consistent, 398 intermittent, and 987 never statin users. There was a significant interaction between age, statin, and HIV serostatus for gait speed. Among people with HIV, for every 5-year age increase, gait speed (m/s) decline was marginally greater among consistent versus never statin users {-0.008 [95% confidence interval (CI) -0.017 to -0.00007]; P = 0.048}, with more notable differences between intermittent and never users [-0.017 (95% CI -0.027 to -0.008); P < 0.001]. Similar results were observed among men without HIV. Significant differences in grip strength (kg) decline were seen between intermittent and never users [-0.53 (95% CI -0.98 to -0.07); P = 0.024] and differences between consistent and never users [-0.28 (95% CI -0.63 to 0.06); P = 0.11] were not statistically significant., Conclusions: Among men with and without HIV, intermittent statin users had more pronounced declines in physical function compared with consistent and never users. Consistent statin use does not seem to have a major impact on physical function in men with or without HIV., Competing Interests: K.M.E. has received research funding from Gilead Sciences and payment for consultancy from Gilead Sciences and Viiv Pharmaceuticals. F.J.P. has served as a consultant and/or received honoraria from Gilead, Janssen, ViiV, Merck, and Theratechnologies. J.E.L. has received research funding from Gilead and served as a consultant to ViiV. T.T.B. has served as a consultant to Merck, Gilead, ViiV Healthcare, and Theratechnologies. The other authors have no conflicts of interest to disclose, (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Both aging and treated human immunodeficiency virus (HIV)-infected populations exhibit low-level chronic immune activation of unknown etiology, which correlates with morbidity and mortality. Cytomegalovirus (CMV) infection is common in both populations, but its relation to immune activation is unknown., Methods: T cells from men who have sex with men (22 virologically suppressed HIV+, 20 HIV-) were stimulated with peptides spanning 19 CMV open reading frames, and intracellular cytokine responses were assessed. Soluble and cellular inflammatory markers were assessed by multiplex electrochemiluminescence and flow cytometry, respectively. Frailty was assessed by the Fried criteria., Results: All men had responses to CMV. Proportions of CMV-responsive T cells correlated strongly (r ≥ 0.6 or ≤ -0.6; P < .05) with immunologic markers, depending on donor HIV and frailty status. Markers significantly correlated in some groups after adjustment for multiple comparisons included interferon-γ, tumor necrosis factor-α, interleukin-6, and several chemokines in serum, and the proportion of activated T cells. The magnitude of the CD4 IL-2 response significantly predicted onset of frailty in HIV- nonfrail men, but not in HIV+ nonfrail men., Conclusions: T-cell responses to CMV may strongly influence chronic immune activation in HIV-uninfected and virologically suppressed HIV-infected men, and may predict frailty in HIV-uninfected men.

The distributed lag model (DLM), used most prominently in air pollution studies, finds application wherever the effect of a covariate is delayed and distributed through time. We specify modified formulations of DLMs to provide computationally attractive, flexible varying-coefficient models that are applicable in any setting in which lagged covariates are regressed on a time-dependent response. We investigate the application of such models to rainfall and river flow and in particular their role in understanding the impact of hidden variables at work in river systems. We apply two models to data from a Scottish mountain river, and we fit to some simulated data to check the efficacy of our model approach. During heavy rainfall conditions, changes in the influence of rainfall on flow arise through a complex interaction between antecedent ground wetness and a time-delay in rainfall. The models identify subtle changes in responsiveness to rainfall, particularly in the location of peak influence in the lag structure., (© 2013, The International Biometric Society.)

Buffer strips alongside watercourses are a widely accepted method of reducing nutrient and sediment run-off from agricultural land thereby improving water quality. Little attention, however, has been paid to the ecological status of these areas despite the fact that riparian habitats in good condition can provide multiple benefits. We investigated vegetation patterns and plant-environment relationships within three categories of riparian margins in northeast Scotland. The margins were categorized as unbuffered, buffered, or reference (target), the latter representing the best sites available within the catchments. Vascular plant and soil data were collected from 41 sites along the tributaries of two rivers during 2008 and 2009. Ellenberg indicator values revealed trends of decreasing light availability ( < 0.05) and decreasing pH ( < 0.01) from unbuffered sites to buffered sites to reference sites. Multivariate analysis showed that soil parameters and channel morphology, together with canopy cover and bryophyte abundance, were discriminatory in separating species assemblages. The presence of a tree canopy layer appears to be the key instigator of change in soil conditions and corresponding plant species assemblages. An understanding of the underlying processes is important if vegetation characteristics are to be used effectively as indicators of riparian and water quality and to aid the restoration of riparian habitats., (Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.)

The Tarland Catchment Initiative is a partnership venture between researchers, land managers, regulators, and the local community. Its aims are to improve water quality, promote biodiversity, and increase awareness of catchment management. In this study, the effects of buffer strip installations and remediation of a large septic tank effluent were appraised by water physico-chemistry (suspended solids, NO, NH, soluble reactive P) and stream macroinvertebrate indices used by the Scottish Environmental Protection Agency. It was done during before and after interventions over an 8-yr period using a paired catchment approach. Because macroinvertebrate indices were previously shown to respond negatively to suspended solid concentrations in the study area, the installation of buffer strips along the headwaters was expected to improve macroinvertebrate scores. Although water quality (soluble reactive P, NH) improved downstream of the septic tank effluent after remediation, there was no detectable change in macroinvertebrate scores. Buffer strip installations in the headwaters had no measurable effects (beyond possible weak trends) on water quality or macroinvertebrate scores. Either the buffer strips have so far been ineffective or ineffectiveness of assessment methods and sampling frequency and time lags in recovery prevent us detecting reliable effects. To explain and appreciate these constraints on measuring stream recovery, continuous capacity building with land managers and other stakeholders is essential; otherwise, the feasibility of undertaking sufficient management interventions is likely to be compromised and projects deemed unsuccessful., (Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.)

We investigated a range of microbiological community assays performed on scrapes of biofilms formed on artificial diffusing substrates deployed in 8 streams in eastern Scotland, with a view to using them to characterize ecological response to stream water quality. The assays considered were: Multiplex Terminal Restriction Fragment Length Polymorphism or M-TRFLP (a molecular method), Phospholipid Fatty Acid or PLFA analysis (a biochemical method) and MICRORESP™ (a physiological method) alongside TDI, diatom species, and chlorophyll a content. Four of the streams were classified as of excellent status (3-6μg/L Soluble Reactive Phosphorus (SRP)) with respect to soluble P content under the EU Water Framework Directive and four were of borderline good/moderate or moderate status (43-577μg/L SRP). At each site, 3 replicates of 3 solute diffusion treatments were deployed in a Latin square design. Solute diffusion treatments were: KCl (as a control solute), N and P (to investigate the effect of nutrient enrichment), or the herbicide isoproturon (as a "high impact" control, which aimed to affect biofilm growth in a way detectable by all assays). Biofilms were sampled after 4weeks deployment in a low flow period of early summer 2006. The chlorophyll a content of biofilms after 4weeks was 2.0±0.29mg/m(2) (mean±se). Dry matter content was 16.0±13.1g/m(2). The M-TRFLP was successfully used for generating community profiles of cyanobacteria, algae and bacteria and was much faster than diatom identification. The PFLA and TDI were successful after an increase in the sample size, due to low counts. The MICRORESP(™) assays were often below or near detection limit. We estimated the per-sample times for the successful assays as follows: M-TRFLP: 20min, PLFA 40min, TDI 90min. Using MANOVA on the first 5 principal co-ordinates, all the assays except MICRORESP(™) showed significant differences between sites, but none of the assays showed a significant effect of either initial stream trophic status (as classified by the EU Water Framework Directive using chemical standards for soluble P), or of the diffusing solute treatment. Multiple Procrustes analysis on the ordination results showed that the diatom and M-TRFLP data sets hold distinct, though as yet unexplored, information about the ecological factors affecting stream biofilms. The diatom data were subjected to principal components analysis, to identify which taxa were more strongly influenced by site variables, trophic status or treatment effects. These were Acnanthes lanceolata, A. minutissimma, Nitzchia spp., Coccineis spp. and Navicula spp. Further experimentation and data analysis on a larger number of sites, to identify specific M-TRFLP bands that could be used as indicators linked to specific taxa, are desirable. Results highlight the need for a multifactorial approach to understanding controls on stream ecology., (Copyright © 2011 Elsevier B.V. All rights reserved.)

We studied viral evolution in five human leukocyte antigen (HLA)-B*57 patients recently infected with HIV-1. Escape mutations in HLA-B*57-restricted Gag epitopes were present at study entry in all patients, but were not associated with significant increases in viremia. Conversely, no new escape mutations in HLA-B*57-restricted epitopes or known compensatory mutations were detected in patients who experienced significant increases in viremia. Thus, the development of escape mutations alone does not determine virologic outcome in recently infected HLA-B*57 patients.

Medium to small scale point sources continue to threaten river ecosystems through P loadings. The capacity and timescales of within-river processing and P retention are a major factor in how rivers respond to, and protect downstream ecosystems from, elevated concentrations of soluble reactive P (SRP). In this study, the bio-geochemical response of a small river (approximately 40 km(2) catchment area) was determined before, during and after exposure to a fourteen day pulse of treated sewage effluent using an upstream reach as a control. A wide array of approaches (batch and column simulations to in-situ whole stream metabolism) allowed independent comparison and quantification, of the relative contribution of abiotic and biotic processes in-river P cycling. This enabled, for the first time, separating the relative contributions of algae, bacteria and abiotic sorption without the use of labelled P (radioisotope). An SRP mass balance showed that the ecosystem switched from a P sink (during effluent inputs) to a P source (when effluent flow ceased). However, 65-70% of SRP was retained during the exposure time and remained sequestered two-weeks after-effluent flow ceased. Batch studies treated with biocide gave unrealistic results, but P uptake rates derived by other methods were highly comparable. Downstream of the effluent input, net P uptake by algae, bacteria and sediment (including the biofilm polysaccharide matrix) were 0.2 (+/-0.1), 0.4 (+/-0.3), and 1.0 (+/-0.9) mmol m(-2) day(-1) during effluent exposure. While autotrophic production did not respond to the effluent exposure, heterotrophic production increased by 67% relative to the control and this translated into a 50% increase in biological P uptake rate. Therefore, both biological and abiotic components of stream ecosystems uptake P during exposure to treated sewage effluent P inputs, and maintain a long 'memory' of this input in terms of P storage for considerable timescales after loading., ((c) 2010 Elsevier Ltd. All rights reserved.)

The River Dee, in North East Scotland, is a mountainous river strongly influenced by patterns of snow accumulation and melt from the Cairngorm Mountains. Analysis of this river's flow record from 1929-2004, the longest in Scotland, supports anecdotal evidence that river extreme flows are increasing. There was no detectable change in the overall annual flow patterns. However, an analysis of seasonal data suggested a shift towards increased flows in spring (March-May) and decreased flows in summer (June-August) over the 75 years of the record. Flows in spring exceeded 29 m(3) s(-1) for 50% of the time over the earliest part of the record (1930 to 1954), whereas in the last 25 years of the record (1979 to 2004) 50% of the flows exceeded 35 m(3) s(-1). Precipitation is increasing in the spring and decreasing in July and August. If these trends continue they have important implications for water management in the Dee, with a potential increase in flood risk in spring and the increased possibility of drought in summer. Combined with this increase in flows the river appears to be more responsive to precipitation events in the catchment. In large heterogeneous catchments with a marginal alpine/high latitude climate it is difficult to assess the amount of precipitation falling as snow and its relative accumulation and ablation dynamics on daily to seasonal time scales. Changes in the temporal pattern of coherence between flow and precipitation are thought to be linked to changing snow patterns in the upland part of the catchment. A decreased amount of precipitation occurring as snow has led to higher coherence. We also show that in responsive systems it is important to record river flows at an hourly rather than daily time step in order to characterise peak flow events.

Establishing vegetated buffer strips (VBS) between cropland and watercourses is currently promoted as a principal control of diffuse pollution transport. However, we lackthe mechanistic understanding to evaluate P retention in VBS and predict risks of P transport to aquatic ecosystems. We observed that VBS establishment led to enhanced rates of soil P cycling, increasing soil P solubility and the potential amount leached to watercourses. Soil in VBS, relative to adjacentfields, had increased inorganic P solubility indices, dissolved organic P, phosphatase enzyme activity, microbial diversity, and biomass P. Small relative increases in the pool of soil P rendered labile had disproportionate effects on the P available for leaching. We propose a mechanism whereby the establishment of VBS on previous agricultural land causes a diversifying plant-microbial system which can access previous immobilized soil P from past fertilization or trapped sediment P. Laboratory experiments suggested that sediment-P inputs to VBS were insufficient alone to increase P solubility without biological cycling. Results showthat VBS management may require strategies, for example, harvesting vegetation, to offset biochemical processes that can increase the susceptibility of VBS soil P to move to adjoining streams.

Suppressed IL-12 production and maladaptive immune activation, both of which are ameliorated by successful highly active antiretroviral therapy (HAART), are thought to play important roles in the immunopathogenesis of chronic HIV infection. Despite the important effects of the immunological and virological events of early HIV infection on subsequent disease progression, IL-12 production and immune activation in early infection remain under-defined. To quantify IL-12 production and immune activation during acute/early HIV infection, in the presence and absence of HAART, we performed a prospective, longitudinal study of participants in the Baltimore site of the Acute Infection and Early Disease Research Program, with cross-sectional comparison to healthy control subjects. PBMC cytokine productive capacity and plasma immune activation markers [soluble CD8 (sCD8), sCD4, granzyme B, neopterin, beta2-microglobulin, sIL-2R, sTNFRI, sTNFRII, and IL-12p70] were quantified by ELISA. Notably, PBMC from patients with acute/early HIV infection exhibited in vivo IL-12p70 production along with increased, maximal in vitro IL-12 production. Further, despite evidence from plasma markers of generalized immune activation, no elevation in plasma levels of sCD4 was observed, suggesting relative blunting of in vivo CD4+ T cell activation from the beginning of HIV infection. Finally, despite successful virological responses to HAART, heightened in vivo CD8+ T cell activation, IL-12 production, and IFN activity were sustained for at least 6 months during primary HIV infection. These data underscore the need for comparative mechanistic analysis of the immunobiology of early and chronic HIV infection.

This study evaluates water quality, suspended and bed sediment, ecological and catchment land use data for 13 catchments of the mixed land use River Dee, NE Scotland, where pollution point sources are limited. Samples were collected at key times of biological activity (early and late summers). Mean river water concentrations were smaller in main stem and upland sites and greater in tributaries where agricultural pressures were greater and were 2-41 microgPO(4)-Pl(-1), 8-58 microg total dissolved Pl(-1) and 1-6 mg l(-1) of suspended particulate matter (SPM). SPM was 7-372 times enriched in biologically available P (BAP; determined using an FeO paper strip method) and 2-122 times in organic C relative to bed sediments. Ratios in river water concentrations of BAP attributed to the SPM (0.1-1.0 microgPl(-1)) to PO(4)-P had the greatest range at baseflow (0.01-0.80) with larger values for low land use intensity catchments. During May chlorophyll a concentrations were related to SPM BAP (p<0.001), but later in summer to PO(4)-P, and there was a corresponding change in the organic composition of SPM observed by IR spectroscopy. SPM concentrations and SPM BAP were better related to intensive grassland land use (p<0.001) than was PO(4)-P concentration (p<0.01) and also predicted abundances of filter feeding macroinvertebrates (p<0.001). Within this river system SPM quantity and composition proved to be an indicator of river biogeochemical functioning and requires further investigation as a potentially sensitive monitoring tool and to increase our understanding of chemical ecological links.

Study Objectives: To examine the frequency of highly active antiretroviral therapy (HAART) modifications, the reasons for these modifications, and toxicities of these drugs in patients receiving their first HAART regimen after a diagnosis of acute (< 2 mo from infection) or early (2-12 mo) human immunodeficiency virus (HIV) infection., Patients: Fifty-one patients who were enrolled in the Acute Infection and Early Disease Research Program at a Baltimore, Maryland, site between January 1, 1998, and April 30, 2002, and who chose to start HAART., Measurements and Main Results: Time from initiation of therapy to first modification-defined as change in any HAART drug without an interruption in therapy or as simultaneous discontinuation of all drugs within the regimen-and time from initiation of therapy to reinitiation of therapy were recorded, as well as reasons for modification and reinitiation. With a median follow-up of 1,549 days, 21 (41%) of 51 patients received HAART continuously, but only 10 (20%) continued to receive their original regimen without any modification. Among the 41 patients (80%) who received modified therapy, the main reasons for the first modification were toxicity (16 patients), nonadherence (8), and new data on treatment efficacy or safety (8). Of 30 patients who stopped HAART, 18 restarted HAART at a later time., Conclusion: The high frequency of treatment modification among patients treated after acute or early HIV infection underscores the importance of determining the usefulness of antiretroviral therapy early in HIV infection, and the need for more tolerable regimens if HAART is to be started at this stage.

This study compared the ability of various intracanal restorative materials to restore the stiffness of endodontically treated teeth. We randomly placed bovine central incisors into six groups. We did not instrument negative control teeth, and we instrumented, but did not restore, positive control teeth. We restored teeth in the experimental groups with resin-based composite, resin-based composite plus a fiberglass post, or resin-based composite plus a cemented metal post. We subjected all teeth to nondestructive, compressive testing and recorded the stiffness of each sample. Results indicated that performing endodontic access and instrumentation alone resulted in a 24% loss in tooth stiffness. Teeth restored using an intracanal resin bonding technique alone or in combination with a post regained the stiffness lost from access and instrumentation, and teeth that were restored with bonded resin and a metal post cemented with Panavia 21 cement were significantly stiffer than the untreated negative control group (p < 0.05). Our results suggest that intracanal resin bonding techniques may reduce the need for immediate crown placement after endodontic therapy.

Objectives: To evaluate the effectiveness of urine screening to detect HIV-infected individuals in high-prevalence communities., Methods: Urine HIV testing was performed at 16 discrete events and four ongoing testing sites in Baltimore communities with a high incidence of HIV infection. When possible, positive urine test results were confirmed by blood testing. In addition, we attempted to obtain blood samples from subjects who reported a possible exposure to HIV but did not have a positive urine test., Results: From February 1998 to August 2001, we screened 1718 persons. Overall, 210 persons (12%) were HIV-positive, of whom 169 (80%) had never previously tested positive; 87% of those who tested positive received their results, and most were referred for medical care., Conclusions: Urine-based screening for HIV infection in high-prevalence inner city communities can be an effective tool for identifying and treating infected persons who are unaware of their infection.

T lymphocyte responses to human immunodeficiency virus (HIV) type 1 Gag were measured in 9 patients by interferon-gamma enzyme-linked immunospot assay at 3 time points within 12 months of infection. Patients with early recognition of HIV-1 Gag had lower subsequent HIV-1 load set points, as measured during the first 2 years of infection, compared with those of patients with undetectable Gag-specific responses (median, 4.27 vs. 5.05 log(10) HIV-1 RNA copies/mL, respectively; P=.028). An inverse correlation existed between the magnitude of the Gag-specific responses and the HIV-1 load set point (r=-0.733; P=.025). Early sustained T lymphocyte responses to HIV-1 Gag may be important for the establishment of virus load set point.

An outline of both the scientific and management needs facing the future water quality issues of Scotland is discussed. The scientific needs are considered in terms of monitoring to increase the understanding of hydrochemical processes, issues of scaling, and the need for improved modelling under changing environmental processes. In terms of the management needs, the requirements highlighted relate to improving the ecological quality of Scottish rivers and the implementation of integrated river basin management plans.

The variation in water quality experienced in Scotland reflects differences in the physical environment and land management. These differences occur both as a result of natural variability, societal development and pollutant inputs. A large proportion of the land area of Scotland is upland in nature which is extensively managed. Whereas in the lowlands, intensive land management predominates. In addition, water quality in the lowland areas in the vicinity of Glasgow and Edinburgh is influenced through the legacy of Victorian and latter day industrial and urban development. A general introduction to the spatial distribution of these facets of Scotland and their relation to water quality is presented.

Stream water temperature data from the Girnock burn, a 30-km2 catchment in Scotland were examined for systematic variation across 30 years of record (1968-1997). The data suggest that there has been no change in mean annual temperature with time, but at a seasonal level there is some indication of an increase in mean daily maximum temperatures during the winter (December to February) and spring (March to May) seasons. For the spring season, there is also evidence that mean temperature has increased. There are no apparent or obvious changes in stream flow to account for this. The strong relationship between air and stream temperatures (r2 = 0.96) implies that changes in the stream are the result of changes in the climate. It is possible that this may occur as a result of the effect of increasing air temperatures which may have also reduced the influence of snow and snowmelt on the catchment during the winter and spring seasons.

In regions such as northern Scotland, where winter temperatures are such that the occurrence of snow is borderline under the present climate, potential changes affecting precipitation and temperature regimes may have a disproportionately large impact on snow processes and hydrological behaviour. The physical characteristics of mountainous areas in Scotland mean that the spatial variability of snowpack accumulation is high, as well as the temporal variability caused by the climate. There have been few modelling studies aimed at assessing the significance of snow resources in these areas and none that have adopted a spatially distributed approach. This paper describes the approach taken in applying a new distributed model to a headwater catchment in the Cairngorm Mountains. The results demonstrate the importance of wind on re-distributing snow to create deep accumulations in small sheltered pockets. These accumulations are shown to be important in sustaining baseflows in the rivers, long after snow has melted from the rest of the catchment. The model has also produced a first set of maps showing how predicted snow depths vary across the catchment through the winter.

The Integrated Nitrogen in CAtchments model (INCA) was applied to the River Dee, Aberdeenshire, NE Scotland. To a first approximation the model was able to simulate the annual mean streamwater NO3-N concentrations observed along the length of the main channel. This provided the basis for using INCA to subsequently explore the effects of N deposition and land use management on streamwater NO3-N concentrations and loads. On an annual timescale, the model predictions suggest that NO3-N concentrations will decrease by 5% following a 20% reduction in fertiliser application. Furthermore, model results also suggest that a 50% increase in N deposition will cause a 15% increase in the streamwater NO3-N concentrations. The utility of INCA as a tool for catchment management is discussed, current limitations are highlighted and possible improvements are suggested.

The concept of critical loads has been generally accepted throughout Europe, and increasingly in Asian countries and the rest of the world, as providing the data which forms the basis for international negotiations on abatement strategies for emissions of acidifying pollutants. Central to the determination of quantitative critical loads of acidity for forests (and other ecosystems) is the rate at which the minerals in the soil weather or dissolve. Seven methods for determining these rates on a regional basis for the production of critical load maps have been suggested by the official bodies which are responsible for co-ordinating the European critical load mapping efforts. These methods are largely correlations which require a knowledge of the soil parent material and/or the soil mineralogy. The purpose of this paper is to review these weathering rate calculation methods and to assess whether it is currently possible to calculate numerically accurate critical loads for the production of regional critical load maps. A consideration of the data used to generate these methods and comparisons of the weathering rates calculated using various methods leads to the conclusion that at present it is not. Further work is needed to develop and maintain the initial credibility of critical loads both scientifically and as an aid to policy decisions.

The method used to produce a critical load map of acidity for soils in Great Britain is described. Critical loads were assigned to the dominant soil in each 1 km grid square of the UK national grid. Mineral soils were assigned a critical load based on mineralogy and chemistry, using approaches appropriate to UK conditions. Critical loads for peat soils are based primarily on a maximum acceptable reduction of peat pH, and results from laboratory equilibration studies. The map shows that soils with small critical loads (<0.5 kmol(c) ha(-1) year(-1)) i.e. highly sensitive to acidic deposition, dominate in the north and west of Britain; the south and east are dominated by soils with large critical loads, with small areas of more sensitive soils associated with sandy soil-forming materials. A modified critical load map illustrates the potential impact of agricultural liming on soil critical loads.

The relationship between an objective measure of glycaemic control (glycated haemoglobin (HbA1)) and personality variables was examined in two separate groups of adult Type 1 (insulin-dependent) diabetic patients. Study 1 included 121 patients, all of whom also had subjective self-reporting of treatment compliance assessed, while the first 57 patients had individual differences in intelligence, major dimensions of personality and forgetfulness documented. Study 2 examined 303 patients, all of whom had their major dimensions of personality assessed using a shortened and updated version of the original personality questionnaire. Demographic indices (age, onset-age, duration of diabetes) were assessed in both groups. No significant correlation was found between HbA1 and self-report compliance suggesting that self-reporting may be invalid as a measure of glycaemic control. In study 1 personality and intelligence variables did not correlate significantly with HbA1 values. Older patients with shorter duration of diabetes had significantly better glycaemic control (p < 0.05). A significant correlation was observed between HbA1 concentration and onset-age of diabetes (p < 0.001); the patients who had developed diabetes later in life were achieving better control of their blood glucose. In the larger number of subjects in study 2 no significant correlations were evident between HbA1 and personality variables. It is concluded that the predictors of glycaemic control indexed by HbA1 may be distinct from predictors of self-report compliance and that the latter have limited or no value in providing an assessment of quality of glycaemic control. There is no evidence of an effect of personality on glycaemic control as measured by HbA1.

The IQ scores (WAIS-R) of 100 patients with insulin-treated diabetes (aged 25-52 yr) were compared with those of 100 healthy control subjects who were matched to the diabetic patients for sex, age, education, and social class. The diabetic group had lower WAIS-R performance and verbal IQ scores than the control group (P = 0.017 and P = 0.033, respectively) after controlling for premorbid IQ. The extent of the difference was modest, representing approximately 33% of an SD in IQ. When frequency of severe hypoglycemia was controlled for the difference in performance IQ between the diabetic patient group and the control group was abolished, whereas the difference between the groups in verbal IQ persisted. It is hypothesised that cumulative severe hypoglycemia might be the major factor in the slight performance IQ differences between diabetic patients and control subjects. The origin of the verbal IQ differences, although obscure, might be related to the social impact of the disorder.

Psychometric performance was studied on two occasions in 18 chronic haemodialysis patients. Nine patients treated with rHuEpo performed a battery of psychometric tests before treatment, haemoglobin [mean (SD)] 5.8 (0.6) g/dl and after partial correction of anaemia, haemoglobin 9.3 (1.28) g/dl. The same battery of psychometric tests was administered on two occasions to nine patients (haemoglobin 7.3 (1.2) g/dl) matched with the treatment group for age, educational status and social class, who did not receive rHuEpo. In the rHuEpo-treated group, IQ, measured by the Wechsler Adult Intelligence Scale-Revised, improved by a mean of 8.7 points (P less than 0.01), while in the control group an improvement by a mean of 2.5 points was not significant. Comparison between the groups of the change in IQ score was significant (P = 0.04). There was no change in the mean scores obtained in either group for the other psychometric tests administered including the Paced Auditory Serial Addition Test, Rey auditory verbal learning, and Borkowski verbal fluency test. These results indicate that anaemia makes a reversible contribution to uraemic cognitive dysfunction.

In common with other member states of UN-ECE, maps of critical loads of transboundary air pollutants are to be produced in the UK for different receptor (waters, soils and vegetation) types. These maps will be used as a tool for assessing different deposition scenarios with proposed pollution abatement strategies. This paper presents the methodology, results and a discussion of the principles used in applying critical loads of sulphur as a pilot study for soils in northern England. For the study area, critical load classes for soils vary with geology, drift cover and slope/elevation. The area of soils in which the critical load is exceeded varies significantly according to the type of deposition data utilised.

Ten pre-senile Alzheimer's patients, 11 patients with Korsakoff's psychosis and 11 age- and pre-morbid intelligence-matched controls were given a test of Inspection Time, which estimates the efficiency of visual encoding or iconic memory. Alzheimer's patients had impaired Inspection Time while the Korsakoff group performed very similarly to the controls. Inspection Time performance correlated significantly with psychometric tests of cognitive ability and with clinical tests of cognitive ability (Mini Mental State Examination and Cambridge Mental Disorders of the Elderly Examination). The early stage of information processing measured by the Inspection Time procedure appears to be damaged by the Alzheimer's disease process, and to impose a rate-limiting effect on a wide variety of mental tests.

To examine the hypothesis that episodes of severe hypoglycaemia may cause cumulative cognitive impairment. 100 Type 1 (insulin-dependent) diabetic patients were examined. Their age range was 25-52 years, and the onset of diabetes had occurred after the age of 19 years. Patients with evidence of organic brain disease, including cerebrovascular disease, were excluded. A questionnaire was used to assess the number, frequency and severity of hypoglycaemic episodes experienced during treatment with insulin and the accuracy of this retrospective information was verified from general practice and hospital case-notes. A detailed neuropsychological assessment was undertaken, including tests of pre-morbid and present IQ (Wechsler-Revised), memory and information-processing speed. Significant correlations were observed between the frequency of severe hypoglycaemia and the magnitude of intellectual decline, Performance IQ, inspection time and reaction time (patients with the more frequent hypoglycaemia had poorer performance). Two sub-groups of patients were identified on the basis of their experience of severe hypoglycaemia, and were balanced for pre-morbid IQ, age and duration of diabetes. One sub-group (n = 23) had never experienced severe hypoglycaemia (Group A), whilst the other sub-group (n = 24) had suffered at least five episodes of severe hypoglycaemia (Group B). Group B had greater intellectual impairment than Group A, and Group B also had a significantly slower mean reaction time and higher reaction time variance when compared with Group A.