Assessing the potential impacts of a revised set of on-farm nutrient and sediment 'basic' control measures for reducing agricultural diffuse pollution across England.

The need for improved abatement of agricultural diffuse water pollution represents cause for concern throughout the world. A critical aspect in the design of on-farm intervention programmes concerns the potential technical cost-effectiveness of packages of control measures. The European Union (EU) Water Framework Directive (WFD) calls for Programmes of Measures (PoMs) to protect freshwater environments and these comprise 'basic' (mandatory) and 'supplementary' (incentivised) options. Recent work has used measure review, elicitation of stakeholder attitudes and a process-based modelling framework to identify a new alternative set of 'basic' agricultural sector control measures for nutrient and sediment abatement across England. Following an initial scientific review of 708 measures, 90 were identified for further consideration at an industry workshop and 63 had industry support. Optimisation modelling was undertaken to identify a shortlist of measures using the Demonstration Test Catchments as sentinel agricultural landscapes. Optimisation selected 12 measures relevant to livestock or arable systems. Model simulations of 95% implementation of these 12 candidate 'basic' measures, in addition to business-as-usual, suggested reductions in the national agricultural nitrate load of 2.5%, whilst corresponding reductions in phosphorus and sediment were 11.9% and 5.6%, respectively. The total cost of applying the candidate 'basic' measures across the whole of England was estimated to be £450 million per annum, which is equivalent to £52 per hectare of agricultural land. This work contributed to a public consultation in 2016.

Modelling the cost-effectiveness of mitigation methods for multiple pollutants at farm scale.

Reductions in agricultural pollution are essential for meeting nationally and internationally agreed policy targets for losses to both air and water. Numerous studies quantify the impact of relevant mitigation methods by field experimentation or computer modelling. The majority of these studies have addressed individual methods and frequently also individual pollutants. This paper presents a conceptual model for the synthesis of the evidence base to calculate the impact of multiple methods addressing multiple pollutants in order to identify least cost solutions for multiple policy objectives. The model is implemented as a farm scale decision support tool that quantifies baseline pollutant losses for identifiable sources, areas and pathways and incorporates a genetic algorithm based multi-objective procedure for determining optimal suites of mitigation methods. The tool is generic as baseline losses can be replaced with measured data and the default library of mitigation methods can be edited and expanded. The tool is demonstrated through application to two contrasting farm systems, using survey data on agricultural practices typical of England and Wales. These examples show how the tool could be used to help target the adoption of mitigation options for the control of diffuse pollution from agriculture. The feedback from workshops where Farmscoper was demonstrated is included to highlight the potential role of Farmscoper as part of the farm advisory process.

Variceal haemorrhage and post-traumatic stress disorder.

OBJECTIVE: Post-traumatic Stress Disorder (PTSD) is thought to be relatively common following extremely distressing life-threatening events. Patients with liver cirrhosis can experience severe brisk variceal haemorrhage during which they vomit litres of blood and may exsanguinate. We predicted that a significant proportion of survivors would suffer from PTSD. DESIGN: PTSD assessment of 30 patients who had a haematemesis of more than four units of blood secondary to variceal bleeding and were fully conscious at the time of the bleed. METHOD: Structured Clinical Diagnostic Interview (SCID-DSM-III-R) and self-report measures. RESULTS: Most found the experience distressing, but only 1 out of 30 patients fulfilled DSM-III-R diagnostic criteria for PTSD. CONCLUSIONS: PTSD in a sample of patients who survived life-threatening variceal haemorrhage is much rarer than might reasonably have been anticipated. Possible reasons for this low prevalence of PTSD are discussed.

A prospective evaluation of changes in neuropsychological and liver function tests following transjugular intrahepatic portosystemic stent-shunt.

BACKGROUND/AIMS: This study was designed to assess changes in: (a) neuropsychological tests, measures of memory, quality of life and scores for anxiety and depression; (b) liver function tests; and (c) the relationship between these following transjugular intrahepatic portosystemic stent-shunt. METHODS: Twenty-nine patients undergoing transjugular intrahepatic portosystemic stent-shunt for recurrent variceal haemorrhage, 12 matched patients with cirrhosis and variceal haemorrhage managed with variceal band ligation and 16 normal controls were studied. Patients in any of the groups who were clinically encephalopathic were excluded from the study. Serial changes in the conventional liver function tests and Indocyanine green clearance, and psychometric function (Hospital Anxiety Depression Scale, Rivermead Behavioral Memory Test, Quality of Life and the memory and reaction sub-tests of the Cambridge Automated Neuropsychological Test Assessment Battery) were measured prior to and 1, 3, 9 and 15 months following transjugular intrahepatic porto-systemic stent-shunt. RESULTS: Over a mean follow up of 9.1 months in the transjugular intrahepatic portosystemic stent-shunt group (range 3-28), one patient (3%) developed clinically detectable encephalopathy. Sixty-seven percent of patients with cirrhosis showed evidence of subclinical encephalopathy as compared with the control population. Significant deterioration occurred in the reaction sub-tests of the Cambridge Automated Neuropsychological Test Assessment Battery in patients, both in the transjugular intrahepatic portosystemic stent-shunt group and the controls with cirrhosis, during follow up. Transjugular intrahepatic portosystemic stent-shunt was followed by significant deterioration in levels of anxiety and psychological component of the quality of life. The Rivermead Behavioural Memory Test and the memory sub-test of the Cambridge Automated Neuropsychological Test Assessment Battery did, however, improve significantly at 1 and 15 months after transjugular intrahepatic portosystemic stent-shunt, respectively. Serum alanine aminotransferase, bilirubin and indocyanine green clearance deteriorated significantly following transjugular intrahepatic portosystemic stent-shunt (p <0.001, p <0.001 and p <0.0001, respectively). Significant correlation was observed between changes in the indocyanine green clearance and changes in the complex and simple reaction time subtests of the Cambridge Automated Neuropsychological Test Assessment Battery (r = 0.6 and r = 0.66, respectively). CONCLUSIONS: The results of this study showed that about 67% of patients with cirrhosis were subclinically encephalopathic and that temporary deterioration occurred in the Cambridge Automated Neuropsychological Test Assessment Battery during follow up, both in patients having transjugular intrahepatic portosystemic stent-shunt and in the controls with cirrhosis. These parallel the changes in the liver function tests and indocyanine green clearance. Temporary deterioration was also observed in the Quality of Life and Hospital Anxiety Depression Scale in the transjugular intrahepatic portosystemic stent-shunt group, although the measures of memory improved. Further studies should address the biochemical mechanisms of these changes and the role of prophylactic measures.

Benzodiazepine receptor antagonism improves reaction time in latent hepatic encephalopathy.

Endogenous benzodiazepine-like substances are thought to play a role in the development of hepatic encephalopathy (HE). Ten patients with sub-clinical or latent hepatic encephalopathy (LHE) and ten normal controls were cognitively assessed pre- and post-infusion of 0.2 mg of the benzodiazepine (BZ) antagonist flumazenil in a placebo-controlled, cross-over, double-blind design. Flumazenil infusion resulted in a significant improvement in simple reaction time in patients, but not in controls. Saline infusion had no effect on any of the cognitive measures in either group. Flumazenil appeared to have a particular enhancing effect on the cognitive, as opposed to the motor, component of the reaction time task. This finding supports the view that the benzodiazepine/GABA system is implicated in the bradyphrenia that is characteristic of chronic liver disease, even before hepatic encephalopathy is apparent. We conclude that benzodiazepine receptor antagonism may improve cognitive function, particularly speed of information processing, in patients with latent hepatic encephalopathy.