Significance of left ventricular apical-basal muscle bundle identified by cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy.

AIMS: Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hypertrophic cardiomyopathy (HCM) by expanding our appreciation for the diverse phenotypic expression. We sought to characterize the prevalence and clinical significance of a recently identified accessory left ventricular (LV) muscle bundle extending from the apex to the basal septum or anterior wall (i.e. apical-basal). METHODS AND RESULTS: CMR was performed in 230 genotyped HCM patients (48 ± 15 years, 69% male), 30 genotype-positive/phenotype-negative (G+/P-) family members (32 ± 15 years, 30% male), and 126 controls. Left ventricular apical-basal muscle bundle was identified in 145 of 230 (63%) HCM patients, 18 of 30 (60%) G+/P- family members, and 12 of 126 (10%) controls (G+/P- vs. controls; P < 0.01). In HCM patients, the prevalence of an apical-basal muscle bundle was similar among those with disease-causing sarcomere mutations compared with patients without mutation (64 vs. 62%; P = 0.88). The presence of an LV apical-basal muscle bundle was not associated with LV outflow tract obstruction (P = 0.61). In follow-up, 33 patients underwent surgical myectomy of whom 22 (67%) were identified to have an accessory LV apical-basal muscle bundle, which was resected in all patients. CONCLUSION: Apical-basal muscle bundles are a unique myocardial structure commonly present in HCM patients as well as in G+/P- family members and may represent an additional morphologic marker for HCM diagnosis in genotype-positive status.

Release of phosphorus under reducing and simulated open drainage conditions from overfertilised soils.

Does removal of cations from soil solution during soil reduction stimulate phosphorus (P) release? An ion-exchange resin system was employed to provide a sink during the incubation of twelve soils under fully reducing conditions. This experimental design was considered to better simulate the loss of ions likely to occur under field conditions than more routine batch type closed extraction systems where solutes build-up in the extract solution. The small solute concentrations that remain in the equilibrating solution suggest the mixed resin system acted as an effective sink over the whole experimental period. By maintaining a small P concentration the resin system mimics soil drainage conditions and encourages P release from soil. Measurement of soil P forms by sequential extraction after the incubation period indicated an increase in the amorphous forms present. Here we show that even if the P-containing solution is retained by the soil, the potential for a subsequent P loss is increased under aerobic conditions. The management of drainage systems should try and avoid the onset of anaerobic conditions. Eventually, magnesium- and calcium-based precipitation products could recapture P from drains recycling it in topsoils as fertilizer.

Source strengths, transport pathways and delivery mechanisms of nutrients, suspended solids and coliforms within a small agricultural headwater catchment.

Analysis of water samples and accompanying flow data collected (on ~100 occasions) from well defined land drain outlets located in a small catchment in NE Scotland were made over a five year period. The complex relationship between individual sources that can exist even within a small (200 ha) agriculturally managed headwater catchment was clearly evident. On average ~60% of the measured flow from the catchment outlet was accounted for, with ~50% originating from field drains and 10% from the farmyard. Certain field drains stopped flowing during the summer. Flow from the farmyard was continuous, and because livestock were present all year round also represented a renewable source of potential contaminants. The majority of nitrate and suspended sediment originated directly from field drainage. The variability in nitrate concentration between individual field drains was large and probably reflected differences in soil drainage properties. Farmyard drainage contributed a large proportion of the ammonium, phosphate and Faecal Indicator Organisms (FIO) measured as a flux from the catchment. On numerous sampling occasions the combined flux from individual sources was greater than the corresponding loss measured at the catchment outlet. This was attributed to result from the temporary storage/retention mechanisms (sedimentation, transformation or biological uptake/exchange) that can operate within the stream channel. Despite many fields being grazed and/or receiving regular applications of slurry/manure, the majority ~60% of the total flux of FIO still originated from the 'farmyard', with significant contributions from the field drains only occurring during the autumn. The presence of field drinkers and secure well maintained fencing denying cattle access to the open drainage channel (often a recommended best management practice) may well have contributed to this observation. Benefits to water quality that might arise from riparian management, such as buffer strips in this particular situation may be limited due to the dominant contribution originating from land drains and farmyard.

Are agricultural soils under a continental temperate climate susceptible to episodic reducing conditions and increased leaching of phosphorus?

Soil science research has probably underestimated the significance that short-term, episodic cycles of reduction and oxidation has had on phosphorus (P) reactivity. Here, the effects of eleven pulsed reduction-oxidation (including wet-dry) cycles on soil P dynamics are compared for 12 soils having contrasting properties and all overfertilised with respect to P. The laboratory based incubation conditions attempted to simulate transient waterlogging of the soil profile and involved repeated sampling and analysis of both the solution and solid phase P forms. An initial increase in P concentration in solution that occurred up to and including the fourth full cycle was followed by a sharp decline in concentration for all but one soil. Accompanying changes in the main extractable forms of P, which appeared to be cumulative, could be summarised as a general decline in the organic P fraction and an overall increase in amorphous associated inorganic forms of P. The fact that up to 60% of the total soil P was demonstrated to change its sensitivity for a particular extractant suggests that these operationally defined P forms are susceptible to transformation as a consequence of changing environmental conditions. There was also a suggestion that certain of the changes in P forms were irreversible. While the laboratory conditions imposed do represent extreme conditions the soils only experienced cyclic changes in their moisture regime. If timing and frequency of intense precipitation events are likely to increase, as predicted in many climate change scenarios, then these results suggest that the effects of episodic redox pulses may have implications for P cycling in agricultural soils.

Influence of 150 years of land use on anthropogenic and natural carbon stocks in Emilia-Romagna region (Italy).

Changes in land use/cover that are commonly associated with urbanization can dramatically influence the amount, chemical form, and spatial distribution of carbon (C) stocks. Measured values and relative literature for composition of natural and anthropogenic materials have been compiled. These data are used in conjunction with land cover statistics and expert assessment of building design to calculate C stocks associated with 150 years of land use change and development for an area of the Po River Valley, Northern Italy. Using 4 time periods (1853, 1954, 1976, and 2003), we demonstrate that the C stocks within this densely populated area have undergone considerable modification. A 52% increase in population density has been associated with an increase in the proportion of total C stored in anthropogenic stocks from 0.2% to 6%; this has been accompanied by a one order of magnitude increase in the carbon emission per capita per unit area. These changes have also been accompanied by a major shift in stocks from organic to inorganic forms of C.

The relationship between preretirement occupation and older adults' life satisfaction and self-rated health.

Pensioners currently compose nearly 20% of the British population; men and women can expect to spend an average of about 17 years and 19 years in retirement, respectively. The present study aimed to investigate the roles of preretirement occupation and self-rated health (SRH) on the attainment of life satisfaction in retired people. A total of 121 community-dwelling men and women (M age = 75.8 years, SD = 7.1) completed a survey to assess life satisfaction, self-rated health, retirement stress, retirement adjustment, and recollected aspects of preretirement occupation. Results revealed positive and significant correlations between scores on a life satisfaction measure and SRH, retirement stress, and retirement adjustment (all ps < .001). Path analysis indicated that aspects of previous employment that may predict an adverse influence on current life satisfaction and that engagement in voluntary work appears to have benefits for both life satisfaction and SRH. The authors conclude that many of the adverse effects of preretirement occupation can be helped or avoided through suitable retirement preparation and training.

Coping with retirement: well-being, health, and religion.

The number of elderly people is increasing, and the authors aimed to identify variables associated with older adults' ability to cope with their retirement years. In this study, 133 community-dwelling men and women (M age = 72 years, SD age = 7.6 years) completed a battery of self-report measures. A path analysis showed that internal locus of control (LOC) and good self-rated health were direct predictors of the criterion variable of life coping. However, whereas health remained a stand alone variable, faith in nature and humanity (positive correlation) and the use of coping religion (negative correlation) predicted LOC. Thus, LOC may play a mediatory role between the latter 2 variables and life coping. In turn, spirituality was a predictor of both the faith in nature and humanity variable and the coping religion variable. Additional findings include a positive correlation between self-rated health and seniority of preretirement occupation, a higher health rating for house dwellers compared with bungalow dwellers, and a negative correlation between age and self-rated health. The authors offer some explanations for the outcomes and suggest that the findings will be valuable to those who are responsible for the social welfare of retired people.

Distribution of aquatic macrophytes in contrasting river systems: a critique of compositional-based assessment of water quality.

A brief summary of the historical developments relating to plant distribution and aquatic macrophyte-nutrient indices provided a means of assessing the general context and validity of previous assumptions. This has particular current relevance because of the prominent use of bioindicators for defining nutrient enrichment. A survey of 161 sites distributed across two broadly contrasting groups of rivers (circum-neutral versus alkaline) recorded 110 species of aquatic macrophytes and these have been statistically analyzed to (i) rank and separate the individual effects of local environmental conditions and spatial isolation on species distribution in the two contrasting groups of sites; (ii) calculate a macrophyte index based on plant cover and species indicator values (Mean Trophic Rank, MTR); and finally (iii) investigate the implications for biomonitoring. Chemical, physical and hydrological site attributes together with spatial isolation, each explained a significant and at least partially independent influence over plant species distribution. It was extremely difficult, however, to separate the single effects of different site attributes on plant distribution. While some plant species are more restricted to certain environmental conditions, many appeared indifferent to the range of those being tested. The role played by nutrients (nitrogen (N) and phosphorus (P)) were either mostly indistinguishable from other site attributes (e.g., nitrate from conductivity) or subordinate (e.g., soluble reactive phosphorus, ammonium). It is therefore very unlikely that macrophyte species composition could provide a reliable bioindicator of the surrounding nutrient (N, P) status. The calculation of the plant index illustrated this unreliability by showing that strong correlations existed with many environmental variables, not just inorganic N and P.

Farmyards, an overlooked source for highly contaminated runoff.

Summer sampling of storm runoff generated from areas of roofs and hardstanding situated on four dairy/beef farms has provided novel information regarding its microbiological and chemical quality. All farm hardstandings generated runoff that was contaminated with respect to those pollutants (faecal coliforms, FC, and faecal streptococci, FS, major nutrients, organic carbon) that are ubiquitously associated with faecal matter and urine. The separate analysis of roof runoff indicated that these can contribute significant concentrations of FS, phosphorus (P) and potentially toxic elements such as zinc (Zn), and suggests a level of 'background' contamination originating from wash-off of bird droppings and in the case of Zn galvanised surfaces. On average hardstanding runoff showed enhanced concentrations of >4 orders of magnitude for FC and 2-3 for major nutrients and carbon relative to roof runoff. Organic forms of nitrogen (N) and P contributed significantly (averaging >40%) to the total dissolved fraction in both roof and hardstanding runoff. Part of the substantial variability in composition of runoff samples could be attributed to differences between farms as well as the timing of sample collection during individual storms. Where situations allowed, a comparison of water upstream and downstream of the farmyard demonstrated they acted as a source of multiple contaminants not only during hydrologically active storm events but also during dry periods. Contamination pathways included a combination of both point (e.g., septic overflows) and non-point (e.g., seepage from livestock housing) sources. Farmyards situated within intensive livestock farming areas such as SW Scotland, would be expected to have significant local and accumulated downstream impacts on the aquatic environment. Localised impacts would be particularly important for headwaters and low order streams.

In situ trace metal speciation in lake surface waters using DGT, dialysis, and filtration.

In situ measurements of Fe and Mn by dialysis and diffusive gradients in thin-films (DGT) in 5 lakes (pH 4.7-7.5, ionic strength 0.3-5 mmol l(-1)) and Cu and Zn in an acidic and circumneutral lake were compared to results from on site filtration. For the most acidic lake (pH 4.7) all measurements agreed, indicating an absence of colloids and negligible complexation by organic matter. There was little difference in the Mn concentrations measured by the three techniques for any lake, consistent with it being free from complexation. Zn measured by dialysis in circumneutral water was only slightly higher than DGT measurements, appropriate to only partial complexation. Substantial differences between dialysis and DGT for Cu were consistent with complexation by fulvic and humic substances, though not to the extent predicted by the speciation code WHAM. To achieve a good fit it was necessary to adjust the pK for Cu-fulvic binding from 0.8 to 1.3 and to assume that fulvic substances dominated. The presence of low molecular weight strong binding ligands would also be consistent with the data. Differences between the three measurement methods were greatest for Fe, attributable to the presence of large oxyhydroxide colloids, organic complexation and low molecular weight, reactive hydrolysis products. Fe and Mn concentrations measured by DGT on samples returned to the laboratory were much lower than in situ concentrations, illustrating the need for in situ measurements. While use of two in situ techniques provided useful information on the speciation of these natural waters, further refinements are required for unambiguous characterization of the solution. The use of DGT with a more restricted gel that excludes complexes with humic substances should provide complementary information to in situ dialysis.

The quality of drinking water from private water supplies in Aberdeenshire, UK.

The quality of private water supplies within Aberdeenshire sampled between 1992 and 1998 was analysed with respect to the presence of total coliforms (TC), faecal coliforms (FC), and nitrate. Of the approximately 1750 samples analysed, which included multiple samples from larger supply categories, the individual failure rate was 41%, 30% and 15% for TC, FC and nitrate, respectively. A combined failure rate for these samples was 48%. Failure rates on microbiological grounds displayed a seasonal trend being greater during the latter half of the year. Although this observation is likely to be due to a combination of local and regional scale factors, part of the variability in failure rate was explained by a significant positive relationship with rainfall amount. Concentrations of nitrate tended to display an opposite trend with a greater number of failures occurring during the spring period and no relationship with rainfall was immediately apparent. A relatively small number of samples (< 50) failed simultaneously for both coliforms and nitrate suggesting that the mechanism responsible for the contamination differed. A similar failure rate for samples collected directly from the source (i.e. well) compared with those taken from the potable tap (usually kitchen cold water tap) suggests that it is the groundwater source itself that contributes much of the microbiological and nitrate contamination rather than a storage or supply line contamination mechanism. A more frequent and random sampling of category one F supplies suggested a greater overall failure rate, which has its own implications for deciding an appropriate sampling frequency.

Joint pollution control at a catchment scale: compliance costs and policy implications.

Agricultural activities are one of the major drivers of increased nutrient levels such as nitrogen (N) and phosphorus (P) to both terrestrial and aquatic ecosystems. Elevated nutrient concentrations are associated with degraded water quality that can result in potential impacts for human health and the environment. A recent European study has identified elevated concentrations of N and P for many European river monitoring stations. In many cases the management of N and P has been considered separately here we address the multi-dimensional issue of water quality where the simultaneous management and control of both N and P is considered desirable. Using an integrated modelling approach various nutrient management scenarios are examined. It is found that although the control of N and P involve different farm adjustments and induce different land use changes there is a certain degree of complementarity between these two nutrient controls. The policy implication of ignoring such complementarity is that the appropriate environmental taxes to control the required nutrient losses are overestimated, resulting in unnecessary welfare losses to the society.

Sustainability of Scottish water quality in the early 21st century.

This paper reviews some of the current water quality issues relating to the surface waters of Scotland and highlights some of the key issues likely to be significant over the next decade. The sustainable management of water quality requires an appreciation of the temporal and spatial assessment of the resource, together with an identification of reference or natural conditions from which to determine change, and the elucidation of the drivers of change. Only through this integrated approach, can appropriate management strategies be developed and prioritised, bearing in mind that impacts may be decoupled from sources in both time and space. This paper highlights recent trends in water quality (from a hydrochemical perspective) with separation into three broad groups: rivers, lochs and estuaries. For rivers, a general reduction in concentration of determinants that are more indicative of urban point sources (phosphorus, ammonium, suspended solids, biochemical oxygen demand etc.) is apparent, while in more agriculturally-dominated areas, an increase in concentration of solutes that are considered more diffuse in origin, (e.g. nitrate) is reported. The increasing contribution to total loads from diffuse pollutants is a priority area for both research and policy. Current scientific challenges are to define the most appropriate spatial context within which regional water quality issues can be monitored and managed. It is likely that future emphasis will be placed on making an initial ecoregion based grouping in conjunction with physically defined catchment, which will be used to quantify site-specific impacts. Such an organisational approach will provide a mechanism that enables a targeted monitoring strategy to be developed. This will allow the establishment of ecologically based targets for water quality, and an improved understanding the biogeochemistry of pollution reversibility and ecosystem recovery. It is also fundamental to the development of tools through which to predict the time scale and magnitude of any recovery, such that environmental benefit can be optimised against realistic socio-economic constraints. The inter-relations between water quality objectives and the development of legislation for water resources management in Europe are discussed.