Response of zooplankton to improving water quality in the Scheldt estuary (Belgium)

Data obtained from 14 years of monthly samplings (1996e2009) were used to investigate the response of the crustacean zooplankton community to improving water quality in the Scheldt estuary. A strong reduction of poor water quality indicators, such as NH4þ and BOD5, as well as an increase in oxygen and in chlorophyll a concentrations were observed during the study period. During the study period, important changes were observed in the zooplankton community composition and spatial distribution. From 2007 onwards, most of the calanoid population, previously mainly found in the brackish water reach of the estuary, moved to the freshwater, where they reached higher abundances than previously observed. Simultaneously, cyclopoids populations strongly decreased in freshwater while cladocerans did not change their abundance, except during years with high chlorophyll a concentrations. Redundancy analyses (RDA) showed that the variability within the calanoid population can be explained by the improvement in water quality. Variability within the cyclopoids and cladoceran community is mainly explained by chlorinity and chlorophyll a concentrations. Their presence in the most polluted upstream area until 2007 suggests they are more tolerant to poor water quality than calanoids. Several hypotheses to explain the disappearance of cyclopoids after the move of calanoids to the freshwater are presented and discussed

Groundwater dynamics in a restored tidal marsh are limited by historical soil compaction

In places where tidal marshes were formerly embanked for agricultural land use, these marshes are nowadays increasingly restored with the aim to regain important ecosystem services. However, there is growing evidence that restored tidal marshes and their services develop slowly and differ from natural tidal marshes in many aspects. Here we focus on groundwater dynamics, because these affect several key ecosystem functions and services, such as nutrient cycling and vegetation development. We hypothesize that groundwater dynamics in restored tidal marshes are reduced as compared to natural marshes because of the difference in soil structure. In the macro-tidal Schelde estuary (Belgium), in both a natural and a restored (since 2006) freshwater tidal marsh, we measured depth profiles of soil properties (grain size distribution, LOI (loss on ignition), moisture content and bulk density) and temporal dynamics of groundwater levels along a transect with increasing distance from a tidal creek. X-ray micro CT-scanning was used to quantify soil macroporosity. The restored marsh has a two layered soil stratigraphy with a topsoil of freshly accreted sediment (ranging in depth between 10 and 60 cm, deposited since 2006) and a subsoil of compact relict agricultural soil. We found that both the soil in the natural marsh and the topsoil of the restored marsh consist of loosely packed sediment rich in macropores and organic matter, whereas the relict agricultural soil in the restored marsh is densely packed and has few macropores. Our results show that groundwater level fluctuations in the restored marsh are restricted to the top layer of newly deposited sediment (i.e. on average 0.08 m depth). Groundwater level fluctuations in the natural marsh occur over a larger depth of the soil profile (i.e. on average 0.28 m depth). As a consequence, the reduced groundwater dynamics in restored tidal marshes are expected to alter the subsurface fluxes of water and nutrients, the source sink function and the development of marsh vegetation

Worsening water quality conditions at Inner Puno Bay, Lake Titicaca, Peru, and their effect on Lemna spp. biomass

Although there have been a number of studies on aquatic conditions and the flora and fauna of Lake Titicaca over many decades (Gilson 1939, 1964; Uéno 1967; Richerson et al. 1975), most of this work has been centred on the offshore regions of the main lake. More recently studies have begun to focus on near-shore waters, especially of Inner Puno Bay (Luna 1981; Northcote et al. 1989 (Spanish version 1991)). Here there has been a deterioration in water quality conditions, especially near areas close to a levee built very recently for tourist viewing, called ‘Bahia de los Incas’ (Figs. 1, 2, 3). Water quality there has been degrading and abundant growth of Lemna spp. has been developing (Cruz 2005). To some extent this Lemna growth can take up nutrients (Quispe 1999) and heavy metals (Choque 2000), but these would be released, in part, with annual die-down

Spatial spring distribution of the copepod Eurytemora affinis (Copepoda,Calanoida) in a restoring estuary, the Scheldt (Belgium)

The spatial spring distribution of Eurytemora affinis (adults and C5) in the Scheldt estuary (Belgium) brackish and freshwater reacheswas studied in between 1996 and 2007. The bulk of the E. affinis population being generally situated in the brackish water reach (salinity > 0.5); we studied which environmental factors are responsible for its recent sporadic occurrence in the freshwater estuarine reach. Using PLS analysis, it is shown that its presence upstream is limited by a sufficient oxygen concentration (>4mg l-1) that is associated with temperature. Not only are the environmental conditions in the upstream zone important, but also the frequent presence of an O2 minimum zone in the mid-estuary (O2 min < 1.3mg l-1) seems to block the movement of the downstream E. affinis population in an upstream direction. Occasionally, the bulk of the population is however situated upstream. During these periods, high E. affinis abundancewas also observed in the Durme tributary. Our findings suggest the possibility to use E. affinis as an “indicator” species ofwaterquality, but also lead us to stress the necessity to consider conditions over the entire estuary when studying restoration effects, not exclusively in the zone of interest

Joint effect of myocardial infarction and obesity on the risk of venous thromboembolism: The Tromsø Study

Background: Myocardial infarction (MI) is associated with an increased risk of venous thromboembolism (VTE). Obesity is a recognized risk factor for both MI and VTE. Whether obesity further increases the risk of VTE in MI patients is scarcely investigated. Aim: To study the joint effect of MI and obesity on the risk of VTE. Methods: Study participants (n = 29 410) were recruited from three surveys of the Tromsø Study (conducted in 1994–1995, 2001, and 2007–2008) and followed up through 2014. All incident MI and VTE cases during follow-up were recorded. Cox regression models with MI as a time-dependent variable were used to estimate hazard ratios (HRs) of VTE (adjusted for age and sex) by combinations of MI exposure and obesity status. Joint effects were assessed by calculating relative excess risk and attributable proportion (AP) due to interaction. Results: During a median of 19.6 years of follow-up, 2090 study participants experienced an MI and 784 experienced a VTE. Among those with MI, 55 developed a subsequent VTE, yielding an overall incidence rate (IR) of VTE of 5.3 per 1000 personyears (95% confidence interval [CI]: 4.1–6.9). In the combined exposure group (MI+/ Obesity+), the IR was 11.3 per 1000 person-years, and the adjusted HR indicated a 3-fold increased risk of VTE (HR 3.16, 95% CI: 1.99–4.99) compared to the reference group (MI−/Obesity−). The corresponding AP was 0.46 (95% CI: 0.17–0.74). Conclusions: The combination of MI and obesity yielded a supra-additive effect on VTE risk of which 46% of the VTE events were attributed to the interaction

High Levels of Complement Activating Enzyme MASP-2 Are Associated With the Risk of Future Incident Venous Thromboembolism

Background: Experimental studies have shown that the complement activating enzyme MASP-2 (mannose-binding lectin associated serine protease 2) exhibits a thrombin-like activity and that inhibition of MASP-2 protects against thrombosis. In this study, we investigated whether plasma MASP-2 levels were associated with risk of future venous thromboembolism (VTE) and whether genetic variants linked to MASP-2 levels were associated with VTE risk. Methods: We conducted a population-based nested case-control study involving 410 VTE patients and 842 age- and sex-matched controls derived from the Norwegian Tromsø Study. Logistic regression was used to estimate odds ratios (ORs) of VTE across MASP-2 quartiles. Whole-exome sequencing and protein quantitative trait loci analyses were performed to assess genetic variants associated with MASP-2 levels. A 2-sample Mendelian randomization study, also including data from the INVENT consortium (International Network of Venous Thrombosis), was performed to assess causality. Results: Subjects with plasma MASP-2 in the highest quartile had a 48% higher OR of VTE (OR, 1.48 [95% CI, 1.06–2.06]) and 83% higher OR of deep vein thrombosis (OR, 1.83 [95% CI, 1.23–2.73]) compared with those with MASP-2 levels in the lowest quartile. The protein quantitative trait loci analysis revealed that 3 previously described gene variants, rs12711521 (minor allele frequency, 0.153), rs72550870 (minor allele frequency, 0.045; missense variants in the MASP2 gene), and rs2275527 (minor allele frequency, 0.220; exon variant in the adjacent MTOR gene) explained 39% of the variation of MASP-2 plasma concentration. The OR of VTE per 1 SD increase in genetically predicted MASP-2 was 1.03 ([95% CI, 1.01–1.05] P=0.0011). Conclusions: Our findings suggest that high plasma MASP-2 levels are causally associated with risk of future VTE

High plasma levels of C1-inhibitor are associated with lower risk of future venous thromboembolism

Background - C1-inhibitor (C1INH) is a broad-acting serine protease inhibitor with anticoagulant activity. The impact of C1INH plasma levels within the normal physiological range on risk of venous thromboembolism (VTE) is unknown. We assessed the association of plasma C1INH levels and VTE risk and evaluated the impact of C1INH on thrombin and plasmin generation in ex vivo assays. Methods - A nested case-control study with 405 patients with VTE and 829 age- and sex-matched controls was derived from the Tromsø Study. Odds ratios (ORs) with 95% confidence intervals (95% CI) for VTE were estimated across plasma C1INH quartiles. Genetic regulation of C1INH was explored using quantitative trait loci analysis of whole exome sequencing data. The effect of plasma C1INH levels on coagulation was evaluated ex vivo by calibrated automated thrombography. Results - Individuals with C1INH levels in the highest quartile had a lower risk of VTE (OR 0.68, 95% CI: 0.49-0.96) compared with those with C1INH in the lowest quartile. In subgroup analysis, the corresponding ORs were 0.60 (95% CI: 0.39-0.89) for deep vein thrombosis and 0.85 (95% CI: 0.52-1.38) for pulmonary embolism, respectively. No significant genetic determinants of plasma C1INH levels were identified. Addition of exogenous C1INH to normal human plasma reduced thrombin generation triggered by an activator of the intrinsic coagulation pathway, but not when triggered by an activator of the extrinsic coagulation pathway. Conclusions - High plasma levels of C1INH were associated with lower risk of VTE, and C1INH inhibited thrombin generation initiated by the intrinsic coagulation pathway ex vivo

Developing a new national MDMA policy:Results of a multi-decision multi-criterion decision analysis

BACKGROUND: Ecstasy (3,4-methylenedioxymethamphetamine (MDMA)) has a relatively low harm and low dependence liability but is scheduled on List I of the Dutch Opium Act (‘hard drugs’). Concerns surrounding increasing MDMA-related criminality coupled with the possibly inappropriate scheduling of MDMA initiated a debate to revise the current Dutch ecstasy policy. METHODS: An interdisciplinary group of 18 experts on health, social harms and drug criminality and law enforcement reformulated the science-based Dutch MDMA policy using multi-decision multi-criterion decision analysis (MD-MCDA). The experts collectively formulated policy instruments and rated their effects on 25 outcome criteria, including health, criminality, law enforcement and financial issues, thematically grouped in six clusters. RESULTS: The experts scored the effect of 22 policy instruments, each with between two and seven different mutually exclusive options, on 25 outcome criteria. The optimal policy model was defined by the set of 22 policy instrument options which gave the highest overall score on the 25 outcome criteria. Implementation of the optimal policy model, including regulated MDMA sales, decreases health harms, MDMA-related organised crime and environmental damage, as well as increases state revenues and quality of MDMA products and user information. This model was slightly modified to increase its political feasibility. Sensitivity analyses showed that the outcomes of the current MD-MCDA are robust and independent of variability in weight values. CONCLUSION: The present results provide a feasible and realistic set of policy instrument options to revise the legislation towards a rational MDMA policy that is likely to reduce both adverse (public) health risks and MDMA-related criminal burden

Carriage of Blastocystis spp. in travellers - A prospective longitudinal study

Introduction: A lack of prospective and longitudinal data on pre- and post-travel carriage of Blastocystis spp. complicates interpretation of a positive test post-travel. Therefore we studied dynamics of Blastocystis carriage in a cohort of Dutch travellers. Methods: From the prospective, multicentre COMBAT study among 2001 Dutch travellers, a subset of 491 travellers was selected based on travel destination to 7 subregions (70 or 71 travellers each). Faecal samples taken directly before and after travel were screened for Blastocystis with qPCR, followed, when positive, by sequence analysis to determine subtypes. Results: After exclusion of 12 samples with missing samples or inhibited qPCR-reactions, stool samples of 479 travellers were analysed. Before travel, 174 of them (36.3%) carried Blastocystis and in most of these, the same subtype was persistently carried. However, in 48/174 of those travellers (27.6%; CI95 20.8–36.6%) no Blastocystis or a different subtype was detected in the post-travel sample, indicating loss of Blastocystis during travel. Only 26 (5.4%; CI95 3.7%–8.0%) of all travellers acquired Blastocystis, including two individuals that were already positive for Blastocystis before travel but acquired a different subtype during travel. Discussion: This study shows that Blastocystis carriage in travellers is highly dynamic. The observed acquisition and loss of Blastocystis could either be travel-related or reflect the natural course of Blastocystis carriage. We demonstrate that the majority of Blastocystis detected in post-travel samples were already carried before travel