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Background: Postural orthostatic tachycardia syndrome (POTS) is a disorder of orthostatic intolerance that primarily affects women of childbearing age. The underlying pathophysiology of POTS is not fully understood, but it has been suggested that autoimmunity may play a role. The aim of this study was to compare concentrations of autoantibodies to cardiovascular G protein–coupled receptors between patients with POTS and healthy controls. Methods: Sera were collected from 116 patients with POTS (91% female; medium age, 29 years) and 81 healthy controls (84% female; medium age, 27 years) from Calgary, Canada, and Malmö, Sweden. Samples were evaluated for autoantibodies to 11 receptors (adrenergic, muscarinic, angiotensin II, and endothelin) using a commercially available enzyme-linked immunosorbent assay. Results: Autoantibody concentrations against all of the receptors tested were not significantly different between controls and patients with POTS. The majority of patients with POTS (98.3%) and all controls (100%) had α1 adrenergic receptor autoantibody concentrations above the seropositive threshold provided by the manufacturer (7 units/mL). The proportion of patients with POTS versus healthy controls who fell above the diagnostic thresholds was not different for any tested autoantibodies. Receiver operating characteristic curves showed a poor ability to discriminate between patients with POTS and controls. Conclusions: Patients with POTS and healthy controls do not differ in their enzyme-linked immunosorbent assay–derived autoantibody concentrations to cardiovascular G protein–coupled receptors. These findings suggest that these tests are not useful for establishing the role of autoimmunity in POTS.

Postural tachycardia syndrome (POTS) and vasovagal syncope (VVS) are two disorders of orthostatic intolerance which are often misdiagnosed as the other. In each case, patients experience a reduced health-related quality of life (HRQoL) compared to healthy populations. This study was conducted to test the hypothesis that HRQoL is worse in POTS. POTS patients were recruited from the Dysautonomia International Annual Patient and Caregiver Conference. VVS patient data came from those enrolled in the Second Prevention of Syncope Trial. Participants aged ≥ 18 years (177 POTS and 72 VVS) completed the RAND 36-Item Health Survey, a generic and coherent health-related quality of life survey. POTS patients reported reduced HRQoL compared to VVS patients in physical functioning (42.5 ± 1.7 vs. 76.5 ± 2.9, p

The adverse impacts of agriculture on water quality have been well documented and the practical measures required to mitigate excessive losses of nutrients and fine sediment have been demonstrated to be effective at plot to field scales. Evaluating the long-term, cumulative impact of measures is challenging, however, and the evidence for tangible water quality benefits at a catchment scale is limited. The objective of this study was to evaluate the effectiveness of the Catchment Sensitive Farming (CSF) partnership, a voluntary pollution reduction scheme in England that between 2006 and 2018 provided advice to 19,776 farm holdings covering 34 % of the total farmed area in England. Water quality data from 110 river monitoring sites in catchments ranging from 11 km2 to 2276 km2 was analysed using statistical regression models to compare pollutant concentration trends among sites that varied in the amount and timing of upstream pollution reduction activity. Additional covariates were included to control for potentially confounding changes in pollution pressure caused by: (i) background changes in cropping patterns and livestock numbers, (ii) the uptake of land management measures delivered via other policy mechanisms, and (iii) seasonal and weather-driven variation in water quality. After delivering advice to farmers, there was a delay of at least two years before mitigation measures elicited a detectable improvement in suspended solids (SS) and orthophosphate (OP) at downstream monitoring sites. Across all sites, the percentage reduction in SS concentration was 28 % of the modelled percentage reduction in fine sediment load. The strength of response was site-specific and changes in SS concentration varied from +12 % to -33 %. In absolute terms, CSF was estimated to have reduced the mean SS concentration at sites in target catchments by an average of 4.4 %. Mean OP concentrations in target catchments decreased by an average of 13.0 % (95 % confidence interval 3.7–22.4%) but the overall strength of the water quality response to unit reductions in phosphorus loading was uncertain. CSF measures reduced nitrogen loading by 5 % in target catchments, but there was no evidence that mean concentrations of total oxidised nitrogen (TON) decreased, probably due to the complex and site-specific time lags involved. The combination of pollution load modelling and statistical water quality modelling used in this study provides a framework for testing and quantifying the effectiveness of land management interventions, individually and in combination, but also highlights the importance of establishing a clear counterfactual and accounting for spatially-variable, lagged responses.

1. There is a need to relate changing river flows to ecological response, particularly using methods which do not require extensive new data for water bodies without historical data. This paper describes how local-scale habitat features and changing discharge appear to influence a macroinvertebrate-based biotic index. 2. The study used 87 time-series of river biomonitoring data from upland, wadeable streams with quasi-natural flow regimes across England and Wales. Twenty-seven of the sites were matched to a nearby flow gauging station, and historical, natural flows using a generalized rainfall-runoff model were synthesized for 60 sites. All sites were matched to a River Habitat Survey (RHS) within 1 km. 3. The data were analysed using multilevel linear regression, combining sample- and site-level characteristics as predictors. Common responses were assessed across sites, using the biotic index LIFE (Lotic Invertebrate index for Flow Evaluation), an average of abundance-weighted Flow Groups which indicate the relative preference among taxa for higher velocities with gravel/cobble substrates or slow velocities with finer substrates. The aim was to understand the influence of habitat on macroinvertebrate response to antecedent high and low flow magnitude. 4. There was a positive relationship between LIFE score calculated from spring and autumn samples and antecedent high (Q10) and low flows (Q95). The relationship between summer Q10 and autumn LIFE score was steeper than the relationship between winter Q10 and spring LIFE score. Bed and bank resectioning reduced overall LIFE and increased the steepness of the response of LIFE to low (Q95) flow. 6. The models derived may be used to guide environmental flow allocations and to quantify the relative influence of flow and physical habitat change on macroinvertebrate responses. The interaction between resectioning and low flow has particular implications for the conservation of macroinvertebrate taxa with requirements for faster flowing water.