Towards a systematic method for assessing the impact of chemical pollution on ecosystem services of water systems.

Chemical pollution impinges on the quality of water systems and the ecosystem services (ESs) they provide. Expression of ESs in monetary units has become an essential tool for sustainable ecosystem management. However, the impact of chemical pollution on ESs is rarely quantified, and ES valuation often focuses on individual services without considering the total services provided by the ecosystem. The purpose of the study was to develop a stepwise approach to quantify the impact of sediment pollution on the total ES value provided by water systems. Thereby, we calculated the total ES value loss as a function of the multi-substance potentially affected fraction of species at the HC50 level (msPAF(HC50)). The function is a combination of relationships between, subsequently: the msPAF(HC50), diversity, productivity and total ES value. Regardless of the inherent differences between terrestrial and aquatic ecosystems, an increase of diversity generally corresponded to an increase in productivity with curvilinear or linear effects. A positive correlation between productivity and total values of ESs of biomes was observed. The combined relationships showed that 1% msPAF(HC50) corresponded to on average 0.5% (0.05-1.40%) of total ES value loss. The ES loss due to polluted sediments in the Waal-Meuse river estuary (the Netherlands) and Flemish waterways (Belgium) was estimated to be 0.3-5 and 0.6-10 thousand 2007$/ha/yr, respectively. Our study presents a novel methodology to assess the impact of chemical exposure on diversity, productivity, and total value that ecosystems provide. With sufficient monitoring data, our generic methodology can be applied for any chemical and region of interest and help water managers make informed decisions on cost-effective measures to remedy pollution. Acknowledging that the ES loss estimates as a function of PAF(HC50) are crude, we explicitly discuss the uncertainties in each step for further development and application of the methodology.

Towards an ecosystem service-based method to quantify the filtration services of mussels under chemical exposure.

As filter-feeders, freshwater mussels provide the ecosystem service (ES) of biofiltration. Chemical pollution may impinge on the provisioning of mussels' filtration services. However, few attempts have been made to estimate the impacts of chemical mixtures on mussels' filtration capacities in the field, nor to assess the economic benefits of mussel-provided filtration services for humans. The aim of the study was to derive and to apply a methodology for quantifying the economic benefits of mussel filtration services in relation to chemical mixture exposure. To this end, we first applied the bootstrapping approach to quantify the filtration capacity of dreissenid mussels when exposed to metal mixtures in the Rhine and Meuse Rivers in the Netherlands. Subsequently, we applied the value transfer method to quantify the economic benefits of mussel filtration services to surface water-dependent drinking water companies. The average mixture filtration inhibition (filtration rate reduction due to exposure to metal mixtures) to dreissenids was estimated to be <1% in the Rhine and Meuse Rivers based on the measured metal concentrations from 1999 to 2017. On average, dreissenids on groynes were estimated to filter the highest percentage of river discharge in the Nederrijn-Lek River (9.1%) and the lowest in the Waal River (0.1%). We estimated that dreissenid filtration services would save 110-12,000 euros/million m3 for drinking water production when abstracting raw water at the end of respective rivers. Economic benefits increased over time due to metal emission reduction. This study presents a novel methodology for quantifying the economic benefits of mussel filtration services associated with chemical pollution, which is understandable to policymakers. The derived approach could potentially serve as a blueprint for developing methods in examining the economic value of other filter-feeders exposed to other chemicals and environmental stressors. We explicitly discuss the uncertainties for further development and application of the method.

Towards nationally harmonized mapping and quantification of ecosystem services.

The EU 2020 Biodiversity Strategy requests EU Member States to map and assess ecosystem services within national territories, and to promote and integrate these values into policy-making. This calls for standardized and harmonized data, indicators, and methods to assess ecosystem services within national boundaries. Current approaches for assessing ecosystem services often oversimplify cross-scale heterogeneity, sacrificing the spatial and thematic detail required to support the needs and expectations of decision-makers at different levels. Hence, nationally harmonized models for mapping and quantifying ecosystem services are needed. This paper presents the Natural Capital Model (NC-Model), a spatially-explicit set of models for quantifying and mapping ecosystem services within the Netherlands. Its aim is to support the integration of ecosystem services within spatial planning and policy-making at the national level, contributing to the fulfilment of national and international environmental policy targets. Models introduce previously unexplored combinations of explanatory variables for modelling ecosystem functions and the socioeconomic benefits they accrue, making use of publicly-available and high-resolution spatial data. To capture spatial and thematic heterogeneity across the urban-rural gradient, the NC-Model comprises a subset of ecosystem service models tailored to the urban environment. To demonstrate the model's application, we expand on six urban ecosystem service models and implement them to quantify and map ecosystem services for Municipality of Amsterdam. High-resolution ecosystem supply and use maps provide detailed spatial information useful for supporting spatial planners and decision-makers who wish to optimize the allocation of natural elements while supporting the needs of citizens. They paint a picture on the interlinkages that exist between natural elements, ecological functions, and socioeconomic well-being in a friendly manner, tailored to various audiences with differing priorities. Their open-access nature enables their customization, supporting the sharing of knowledge and data to endorse ecosystem service modelling efforts by external parties within and outside the Netherlands.

Quantifying biomass production for assessing ecosystem services of riverine landscapes.

Society is increasingly in need of renewable resources to replace fossil fuels and to prevent resource depletion. River-floodplain systems are known to provide important societal functions and ecosystem services to mankind, such as production of vegetative biomass. In order to determine the potential of harvesting vegetative riparian biomass, the capacity of river systems to produce such biomass needs to be determined. We developed a method for quantifying the spatiotemporal development of annual biomass production in river floodplains. Vegetation specific growth rates were linked to a landscape classification system (i.e., the Ecotope System for National Waterways). Biomass production was calculated for floodplains along the three Rhine River distributaries (i.e., the rivers Waal, Nederrijn-Lek and IJssel) over a 15year period (1997-2012). During this period several large scale river management measures were undertaken to reduce flood risks and improve the spatial quality of the Rhine River as part of the Room for the River program. Biomass production decreased by 12%-16% from 1997 to 2012 along the three distributaries, which may be a side effect of flood mitigation. Almost 90% of the biomass produced was non-woody (e.g., grass/hay, reed, crops), which decreased along all three river distributaries due to the abandonment of production grasslands and the physical reconstruction of floodplains (e.g., creation of side channels). Woody vegetation, however, showed a slight increase during the 15year period likely owing to vegetation succession from shrubs to softwood forest.

Fatal rupture of a mycotic aneurysm of the right coronary artery post pneumococcal sepsis.

Aneurysms of the coronary arteries are rare and mycotic coronary aneurysms are even rarer. We report a unique, yet unfortunately autopsy-proven fatal case of a ruptured atherosclerotic mycotic aneurysm of the right coronary artery with streptococcus pneumoniae in a non-immunocompromised patient resulting in cor tamponade and death.

Brain dopamine and serotonin transporter binding are associated with visual attention bias for food in lean men.

BACKGROUND: In rodents, the striatal dopamine (DA) system and the (hypo)thalamic serotonin (5-HT) system are involved in the regulation of feeding behavior. In lean humans, little is known about the relationship between these brain neurotransmitter systems and feeding. We studied the relationship between striatal DA transporters (DAT) and diencephalic 5-HT transporters (SERT), behavioral tasks and questionnaires, and food intake. METHOD: We measured striatal DAT and diencephalic SERT binding with [123I]FP-CIT SPECT in 36 lean male subjects. Visual attention bias for food (detection speed and distraction time) and degree of impulsivity were measured using response-latency-based computer tasks. Craving and emotional eating were assessed with questionnaires and ratings of hunger by means of VAS scores. Food intake was assessed through a self-reported online diet journal. RESULTS: Striatal DAT and diencephalic SERT binding negatively correlated with food detection speed (p = 0.008, r = -0.50 and p = 0.002, r = -0.57, respectively), but not with food distraction time, ratings of hunger, craving or impulsivity. Striatal DAT and diencephalic SERT binding did not correlate with free choice food intake, whereas food detection speed positively correlated with total caloric intake (p = 0.001, r = 0.60), protein intake (p = 0.01, r = 0.44), carbohydrate intake (p = 0.03, r = 0.39) and fat intake (p = 0.06, r = 0.35). CONCLUSIONS: These results indicate a role for the central 5-HT and DA system in the regulation of visual attention bias for food, which contributes to the motivation to eat, in non-obese, healthy humans. In addition, this study confirms that food detection speed, measured with the latency-based computer task, positively correlates with total food and macronutrient intake.

Insulin resistance in obesity can be reliably identified from fasting plasma insulin.

BACKGROUND/OBJECTIVES: Insulin resistance is the major contributor to cardiometabolic complications of obesity. We aimed to (1) establish cutoff points for insulin resistance from euglycemic hyperinsulinemic clamps (EHCs), (2) identify insulin-resistant obese subjects and (3) predict insulin resistance from routinely measured variables. SUBJECTS/METHODS: We assembled data from non-obese (n=112) and obese (n=100) men who underwent two-step EHCs using [6,6-(2)H2]glucose as tracer (insulin infusion dose 20 and 60 mU m(-2) min(-1), respectively). Reference ranges for hepatic and peripheral insulin sensitivity were calculated from healthy non-obese men. Based on these reference values, obese men with preserved insulin sensitivity or insulin resistance were identified. RESULTS: Cutoff points for insulin-mediated suppression of endogenous glucose production (EGP) and insulin-stimulated glucose disappearance rate (Rd) were 46.5% and 37.3 µmol kg(-)(1) min(-)(1), respectively. Most obese men (78%) had EGP suppression within the reference range, whereas only 12% of obese men had Rd within the reference range. Obese men with Rd <37.3 µmol kg(-1) min(-1) did not differ from insulin-sensitive obese men in age, body mass index (BMI), body composition, fasting glucose or cholesterol, but did have higher fasting insulin (110±49 vs 63±29 pmol l(-1), P<0.001) and homeostasis model assessment of insulin resistance (HOMA-IR) (4.5±2.2 vs 2.7±1.4, P=0.004). Insulin-resistant obese men could be identified with good sensitivity (80%) and specificity (75%) from fasting insulin >74 pmol l(-1). CONCLUSIONS: Most obese men have hepatic insulin sensitivity within the range of non-obese controls, but below-normal peripheral insulin sensitivity, that is, insulin resistance. Fasting insulin (>74 pmol l(-1) with current insulin immunoassay) may be used for identification of insulin-resistant (or metabolically unhealthy) obese men in research and clinical settings.

Effect of selective serotonin re-uptake inhibitors (SSRIs) on functional outcome in patients with acute ischemic stroke treated with tPA.

BACKGROUND: Selective serotonin re-uptake inhibitors (SSRIs) may have therapeutic potential in the treatment of ischemic stroke by effects on neuronal cell survival and the plasticity of brain processes. In the present study, we investigated whether prior treatment with a SSRI is associated with more favorable functional outcome in a cohort of patients with acute ischemic stroke treated with tissue plasminogen activator (tPA). METHODS: In a prospective observational cohort study of 476 acute ischemic stroke patients treated with tPA we investigated the relationship between prior SSRI treatment and functional outcome at 3 months. Ischemic stroke subtypes were defined according to the Oxfordshire Community Stroke Project Classification. Favorable outcome was defined as a modified Rankin Scale score

Statin use and functional outcome after tissue plasminogen activator treatment in acute ischaemic stroke.

BACKGROUND: Preliminary findings suggest that statins may have a neuroprotective effect in patients with acute ischaemic stroke. This study investigated whether patients on prior statin therapy and treated with tissue plasminogen activator (tPA) for acute ischaemic stroke have a better functional outcome than statin-naïve patients. METHODS: In a prospective observational cohort study of 476 acute ischaemic stroke patients treated with tPA we investigated the relationship between prior statin use and functional outcome at 3 months, the occurrence of symptomatic intracerebral haemorrhage (SICH) and early in-hospital mortality. Ischaemic stroke subtypes were defined according to the TOAST classification. Favourable outcome was defined as a modified Rankin Scale score < or =2. RESULTS: Of the 476 patients included, 98 (20.6%) used a statin at stroke presentation. In the entire cohort, 45.6% of patients had a favourable outcome with no difference between patients with or without statin therapy (45.9 vs. 45.5%, p = 0.94). In the multivariable analysis, statin use was not associated with favourable outcome (OR = 1.1, 95% CI = 0.6-1.9, p = 0.87). In none of the different stroke subtype groups was statin use associated with favourable outcome. Finally, statin use was not an independent risk factor of SICH or of early in-hospital mortality. CONCLUSION: Prior statin therapy in patients with acute ischaemic stroke treated with tPA is not associated with a more favourable outcome, and this is independent of stroke subtype.

Hyperdense middle cerebral artery sign and outcome after intravenous thrombolysis for acute ischemic stroke.

BACKGROUND: The presence of a hyperdense middle cerebral artery sign (HMCAS) on baseline brain CT is associated with poor clinical outcome in stroke patients treated with intravenous recombinant tissue plasminogen activator (tPA). It remains uncertain whether the presence of HMCAS is associated with acute neurological deterioration after tPA treatment. OBJECTIVE: To evaluate the effect of HMCAS in routinely intravenous tPA-treated patients with anterior circulation stroke on acute neurological deterioration, the 3-month functional outcome and the occurrence of symptomatic ICH. METHODS: We analyzed data from a single stroke unit registry of 384 consecutive patients with anterior circulation infarction, treated with intravenous tPA. Logistic regression models were used to assess if HMCAS was independently associated with predefined outcome definitions. RESULTS: We found a HMCAS in 104 patients (27%). The HMCAS was related to the risk of early neurological deterioration (p=0.04) and poor functional outcome (p<0.001) on univariate analysis. The incidence of symptomatic ICH was not significantly different between patients with and without HMCAS (7% versus 6%, p=0.81). In the multivariable analysis, the presence of HMCAS was significantly associated with a poor outcome (p=0.004). CONCLUSIONS: The HMCAS is associated with early neurological deterioration and poor functional outcome, but not with symptomatic ICH.

Development and validation of a predictive outcome score of cerebral venous thrombosis.

BACKGROUND AND PURPOSE: Cerebral venous thrombosis (CVT) is a rare disease with a variable outcome. The aim of this study was to develop and validate a predictive outcome score for CVT patients. METHODS: The score was based on the 8 predictive variables of poor outcome (modified Rankin Scale score>2) from the International Study on Cerebral Vein and Dural Sinus Thrombosis: age >37, male, mental status disorder, coma, intracranial hemorrhage, deep CVT, CNS infection, and malignancy. To assign a weighted index (WI), the natural logarithm of the hazard ratio of each variable was calculated, multiplied by 10 and rounded to the nearest integer. The individual score of each patient was the sum of the WI. The validation sample consisted of a retrospective single center cohort of 90 CVT patients. RESULTS: Sixteen patients (18%) had a poor outcome. The predictive score had an area under the receiver operating characteristic curve of 0.81 (95% CI 0.71-0.90). The cut-off score with the maximum sum of sensitivity and specificity was a score> or =14 with sensitivity of 88% (81%-95%) and specificity of 70% (61%-79%). The predictive value of a score<14 for good outcome was 96% (92%-100%), whereas the predictive value of a score> or =14 for poor outcome was 39% (29%-49%). CONCLUSIONS: This relatively simple predictive outcome score may be useful in CVT patients. A cut-off score of 14 reliably predicts good outcome, but is less accurate in predicting poor outcome.

An often unrecognized cause of thunderclap headache: reversible cerebral vasoconstriction syndrome.

Thunderclap headache (TCH) can have several causes of which subarachnoid hemorrhage (SAH) is most common and well known. A rare cause of TCH is the reversible cerebral vasoconstriction syndrome (RCVS) which is characterized by a reversible segmental vasoconstriction of the intracranial vessels. We describe two patients with TCH due to RCVS and the probable precipitating factor, namely, cannabis and an anti-migraine drug. In RCVS, cerebrospinal fluid examination is (near) normal, in contrast to SAH and (primary) cerebral vasculitis. Brain MRI may be normal or shows infarction. MRA can demonstrate vasoconstriction of the great arteries, but a normal MRA does not rule out the diagnosis. Caliber changes on cerebral angiography cannot adequately differentiate between RCVS and vasculitis. Calcium-channel antagonists may be a good therapy and repeated transcranial Doppler ultrasonography can be a reliable non-invasive investigation to monitor the effect of treatment and demonstrate reversibility of the vasoconstriction.

Lipid profile, statin use, and outcome after intravenous thrombolysis for acute ischaemic stroke.

BACKGROUND: Low cholesterol levels have been associated with an increased risk of haemorrhagic stroke. This study investigated whether lipid levels or prior statin use influence outcome in patients with acute ischaemic stroke treated with IV thrombolysis. METHODS: The relation between admission lipid levels or statin use and both the development of symptomatic intracerebral haemorrhage (sICH) and 3-months functional outcome was assessed in a prospective hospital-based stroke registry comprising 252 patients treated with IV tissue plasminogen activator (tPA). The fasting status of the patients was unknown. Favourable outcome at 3 months was defined as a modified Rankin scale score

Pitfalls in the diagnosis of reversible cerebral vasoconstriction syndrome and primary angiitis of the central nervous system.

A case of a 51-year-old woman with reversible cerebral vasoconstriction syndrome (RCVS) without an associative cause is reported. Initially the diagnosis primary angiitis of the central nervous system (PACNS) was considered. Both diagnosis are rare and can mimic each other. Distinction between both can be difficult, but is necessary because of different treatment options. Clinical features and diagnostic assessments to distinguish RCVS from PACNS and the potential pitfalls are discussed.