Evaluation of river basin restoration options by the application of the Water Framework Directive Explorer in the Zwalm River basin (Flanders,Belgium)

Water managers and researchers strive towards the same objective: the improvement of the quality status of water bodies. However, there is still a gap between the results of academic studies on water systems and the information currently used in water management. The Water Framework Directive (WFD)‐Explorer, a modular toolbox which supports integrated water management in a river basin, attempts to bridge this gap. The toolbox analyses the impact of different restoration measures on river ecology based on expert rules embedded in this simulation environment. The strengths and weaknesses of the toolbox have been tested on the Zwalm River basin in Flanders, Belgium. The ecological status of streams in the basin spans the whole range of nearly pristine headwaters to severely impacted river stretches further downstream. Considering the key bottlenecks in the Zwalm basin and the user‐driven ecological status objectives, several water quality and physical habitat restoration options have been proposed to meet the European Water Framework Directive goals. The positive impact of restoration measures on the ecological quality ratio (EQR) for macroinvertebrates appeared to be the highest for measures affecting the nutrient inflows and thus chemical water body characteristics. However, the spatial scale on which the WFD‐Explorer modelled the impact of physical habitat restoration may have been too coarse to generate reliable results concerning such restoration measures. Hence, the combination of the WFD‐Explorer results with those of more detailed studies on physical habitat restoration impacts might be a promising approach to reliably support decision‐making implementation of the WFD. Copyright © 2008 John Wiley & Sons, Ltd.     

Condition-based consensus solvability: a hierarchy of conditions and efficient protocols

The condition-based approach for consensus solvability consists of identifying sets of input vectors, called conditions, for which there exists an asynchronous protocol solving consensus despite the occurrence of up to f process crashes. This paper investigates , the largest set of conditions which allow us to solve the consensus problem in an asynchronous shared memory system.The first part of the paper shows that is made up of a hierarchy of classes of conditions, where d is a parameter (called degree of the condition), starting with and ending with d = 0, where . We prove that each one is strictly contained in the previous one: . Various properties of the hierarchy are also derived. It is shown that a class can be characterized in two equivalent but complementary ways: one is convenient for designing protocols while the other is for analyzing the class properties. The paper also defines a linear family of conditions that can be used to derive many specific conditions. In particular, for each d, two natural conditions are presented.The second part of the paper is devoted to the design of efficient condition-based protocols. A generic condition-based protocol is presented. This protocol can be instantiated with any condition C, , and requires at most shared memory read/write operations per process in the synchronization part of the protocol. Thus, the value (f-d) represents the difficulty of the class . An improvement of the protocol for the conditions in is also presented.Received: 15 November 2001, Accepted: 15 April 2003, Published online: 6 February 2004Parts of it have previously appeared in [23] and [25].     

Blind jealousy? Romantic insecurity increases emotion-induced failures of visual perception.

Does the influence of close relationships pervade so deeply as to impact visual awareness? Results from two experiments involving heterosexual romantic couples suggest that they do. Female partners from each couple performed a rapid detection task where negative emotional distractors typically disrupt visual awareness of subsequent targets; at the same time, their male partners rated attractiveness first of landscapes, then of photos of other women. At the end of both experiments, the degree to which female partners indicated uneasiness about their male partner looking at and rating other women correlated significantly with the degree to which negative emotional distractors had disrupted their target perception during that time. This relationship was robust even when controlling for individual differences in baseline performance. Thus, emotions elicited by social contexts appear to wield power even at the level of perceptual processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An emotion-induced attentional blink elicited by aversively conditioned stimuli.

The current study examines whether aversively conditioned stimuli can modulate attention to such a degree that they impair the perception of subsequently presented nonemotional targets. In the initial phase of this study, participants viewed 3 categories of photographs, 1 of which was paired with an aversive noise. Following conditioning, participants searched for a target embedded within a series of 17 rapidly presented images on each trial. Critically, a conditioned or unconditioned item from the initial phase appeared 200 ms or 800 ms before the target. At 200-ms lags but not 800-ms lags, the conditioned images impaired target detection relative to the other distractors. Thus, temporary visual deficits can be induced by otherwise neutral distractors whose aversive associations have only recently been learned. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of citric acid supplements to a maize-soya diet on the in vitro availability of minerals, trace elements, and heavy metals

The aim of the present study was to evaluate the effect of increasing supplements of citric acid (CTA) on the in vitro availability of mineral (Ca, Mg), trace elements (Mn, Zn) and heavy metals (Pb, Cd). Phytaterich diets (0.8%) based on maize, soybean meal, corn starch and soybean oil (containing 5.0 g Ca, 1.2 g Mg, 50 mg Mn, 22 mg Zn, 10 mg Pb and 5 mg Cd per kg diet) were supplemented with 0, 1, 2, 3 and 4% of CTA. All diets were treated in a multi-enzyme in vitro system followed by equilibrium dialysis after peptic and pancreatic digestion. Under the conditions investigated, dietary addition of CTA enhanced dialysability of calcium, magnesium, manganese and zinc. Furthermore, a dose-dependent increase of lead and cadmium dialysability due to CTA supplementations was evident.     

Glucoraphanin does not reduce plasma homocysteine in rats with sufficient Se supply via the induction of liver ARE-regulated glutathione biosynthesis enzymes

Data from human and animal trials have revealed contradictory results regarding the influence of selenium (Se) status on homocysteine (HCys) metabolism. It was hypothesised that sufficient Se reduces the flux of HCys through the transsulphuration pathway by decreasing the expression of glutathione (GSH) synthesising enzymes. Glucoraphanin (GRA) is a potent inducer of genes regulated via an antioxidant response element (ARE), including those of GSH biosynthesis. We tested the hypothesis that GRA supplementation to rat diets lowers plasma HCys levels by increasing GSH synthesis. Therefore 96 weaned albino rats were assigned to 8 groups of 12 and fed diets containing four different Se levels (15, 50, 150 and 450 μg kg(diet)(-1)), either without GRA (groups: C15, C50, C150 and C450) or in combination with 700 μmol GRA kg(diet)(-1) (groups G15, G50, G150 and G450). Rats fed the low Se diets C15 and G15 showed an impressive decrease of plasma HCys. Se supplementation increased plasma HCys and lowered GSH significantly by reducing the expression of GSH biosynthesis enzymes. As new molecular targets explaining these results, we found a significant down-regulation of the hepatic GSH exporter MRP4 and an up-regulation of the HCys exporter Slco1a4. In contrast to our hypothesis, GRA feeding did not reduce plasma HCys levels in Se supplemented rats (G50, G150 and 450) through inducing GSH biosynthesis enzymes and MRP4, but reduced their mRNA in some cases to a higher extent than Se alone. We conclude: 1. That the long-term supplementation of moderate GRA doses reduces ARE-driven gene expression in the liver by increasing the intestinal barrier against oxidative stress. 2. That the up-regulation of ARE-regulated genes in the liver largely depends on GRA cleavage to free sulforaphane and glucose by plant-derived myrosinase or bacterial β-glucosidases. As a consequence, higher dietary GRA concentrations should be used in future experiments to test if GRA or sulforaphane can be established as HCys lowering compounds.     

Reaction zone characterization of counter-flow diffusion flame with diluted and preheated reactants

Reaction zone characteristics were studied using hydroxy radical planar laser-induced fluorescence (OH-PLIF) technique for a counter-flow preheated (CH4+N2)/(Air+N2) diluted diffusion flames. The effects of preheat temperature and dilute ratio on the reaction zone characteristics were investigated by demonstrating the OH intensity distribution and reaction zone thickness from OH-PLIF images. Under the experimental conditions of constant cold flow velocity, the results show that the OH intensity and reac-tion zone thickness decrease with the increase of dilute ratio at constant preheat temperature and increase with preheat temperature at fixed dilute ratio. The OH maximum intensity shifts towards the "lean" side of counter flow at constant preheat temperature, and it shifts towards the fuel side with the increase of dilute ratio of fuel stream and towards the oxidizer side with the increase of dilute ratio of oxidizer stream respectively. The feasibility of OH as a reaction zone marker in this diluted combustion is verified further. The variation of diffusion and chemical reaction rate of reactants due to preheat and dilution contributes to the reaction zone characteristics simultaneously. The effect of strain on the flame reaction zone should be included in the future work.     

Economic effects of community versus hospital-based faculty pneumonia care

To compare the length of stay and charges for patients with pneumonia admitted in 1995 to the teaching and nonteaching services of a Northeastern teaching hospital, we reviewed the charts of 237 patients. Patients cared for by hospital-based generalists working with housestaff (teaching service) were discharged more quickly and with lower or equivalent charges than patients cared for by community-based attending physicians working either with housestaff (private teaching service) or alone (nonteaching service). Academic teaching services staffed by general medicine faculty may provide efficient inpatient pneumonia care.     

Assessment of ignition hazard in turbulent flammable gas mixers combining a Lagrangian approach and large eddy simulation

In this article, a Lagrangian approach is adopted to assess both mixing efficiency and ignition hazard of fuel/oxygen flammable gas mixing in a jets-in-cross-flow configuration. Large eddy simulation is used to provide the unsteady fields of turbulent gas mixing. To achieve statistical reliability of the fluid dynamics field, such as velocity, pressure, temperature, and chemical composition, a large number of Lagrangian markers are dumped into the inlet streams of the mixer and their trajectories are determined during the numerical simulation. Those trajectories are stored in a file processed afterward to build up the probability density functions of the fuel molar fraction of Lagrangian markers gauging both mixer efficiency and safety. Flammability limits provided by H.F. Coward and G.W. Jones [U.S. Bur. Mines Bull. 503 (1952)] and autoignition delays from a detailed kinetics scheme are required to define the hazard range. Processing the marker trajectory file allows the calculation of relevant Lagrangian properties such as (i) the critical residence time in flammability areas for the ignition case and (ii) the marker Damköhler number for the autoignition case, both including the subgrid turbulence effects. The latter are accounted for by assuming a presumed beta shape for the large eddy probability density function of subgrid fluctuations of mixture fraction. Analysis of all marker trajectories leads to a computation of global probability density functions of Lagrangian properties that characterize mixer safety.