8,643 research outputs found
A NEW “FERROVUM” SPECIES IN A SCHWERTMANNITE-PRODUCING PLANT FOR MINE WATER TREATMENT
Mining activities for metals or coal often result in the development of acid mine drainage
due to the oxidation of sulfidic minerals which get exposed to oxygen. The acidic mine waters are
characterized by low pH, high concentrations of sulfate and ferrous iron, and possibly dissolved
heavy metals or metalloids. Conventional treatment comprises neutralization and oxidation yielding
a sludge of iron oxides/hydroxides
A stochastic individual based model for the growth of a stand of Japanese knotweed including mowing as a management technique
Invasive alien species are a growing threat for environment and health. They
also have a major economic impact, as they can damage many infrastructures. The
Japanese knotweed (Fallopia japonica), present in North America, Northern and
Central Europe as well as in Australia and New Zealand, is listed by the World
Conservation Union as one of the world's worst invasive species. So far, most
models have dealt with how the invasion spreads without management. This paper
aims at providing a model able to study and predict the dynamics of a stand of
Japanese knotweed taking into account mowing as a management technique. The
model we propose is stochastic and individual-based, which allows us taking
into account the behaviour of individuals depending on their size and location,
as well as individual stochasticity. We set plant dynamics parameters thanks to
a calibration with field data, and study the influence of the initial
population size, the mean number of mowing events a year and the management
project duration on mean area and mean number of crowns of stands. In
particular, our results provide the sets of parameters for which it is possible
to obtain the stand eradication, and the minimal duration of the management
project necessary to achieve this latter
Bibliothèque Sainte-Barbe - Rapport d\u27activité 2017
Rapport d\u27activité de la bibliothèque Sainte-Barbe pour l\u27année 2017
Long-term retrospective analysis of mackerel spawning in the North Sea: a new time series and modeling approach to CPR data
We present a unique view of mackerel (Scomber scombrus) in the North Sea based on a new time series of larvae caught by the Continuous Plankton Recorder (CPR) survey from 1948-2005, covering the period both before and after the collapse of the North Sea stock. Hydrographic backtrack modelling suggested that the effect of advection is very limited between spawning and larvae capture in the CPR survey. Using a statistical technique not previously applied to CPR data, we then generated a larval index that accounts for both catchability as well as spatial and temporal autocorrelation. The resulting time series documents the significant decrease of spawning from before 1970 to recent depleted levels. Spatial distributions of the larvae, and thus the spawning area, showed a shift from early to recent decades, suggesting that the central North Sea is no longer as important as the areas further west and south. These results provide a consistent and unique perspective on the dynamics of mackerel in this region and can potentially resolve many of the unresolved questions about this stock.lved questions about this stoc
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That smells filling: effects of pairings of odours with sweetness and thickness on odour perception and expected satiety
Retronasal co-experience of odours with sweet tastes and thick textures have been shown to result in attribution of sweetness and thickness to odours when they are subsequently sniffed. Orosensory thickness and creaminess are also associated with expectations that a product will be filling. Here we test for the first time whether co-experience of odours with orosensory thickness and sweetness results in transfer of satiety expectations to these odours when subsequently sniffed. Eighty healthy volunteers evaluated the hedonic and sensory characteristics of odours, and expectations that products with the same flavour as the odour would be filling, before and after disguised co-experience of odours with sweetness (sucrose), thickness (tara gum solution) or the combination of sweet/thick, as well as untrained (control) odours. Odours paired with tara gum were subsequently rated as smelling thicker and more creamy, while odours paired with sucrose smelled sweeter. Pairing odours with tara gum increased the expectation that products predicted to have the same flavour as the sniffed odour would be more filling, and this was enhanced by sweetness, while pairing odours with tara-gum increased the expectation that products with that odour would reduce later hunger. Liking for odours paired with sweetness increased, but pairing with thickness alone reduced liking. These data suggest that satiety-consonant sensory characteristics can transfer to associated odours, and that this process is independent of changes in liking. This raises the possibility of using satiety-associated odour cues to manipulate consumer satiety expectations
Dynamics of the Formin For3p in Actin Cable Assembly
SummaryBackgroundFormins are a conserved family of actin nucleators responsible for the assembly of diverse actin structures such as cytokinetic rings and filopodia. In the fission yeast Schizosaccharomyces pombe, the formin for3p is necessary for the formation of actin cables, which are bundles of short parallel actin filaments that regulate cell polarity. These filaments are largely organized with their barbed ends facing the cell tip, where for3p is thought to function in their assembly.ResultsHere, using a functional for3p-3GFP fusion expressed at endogenous levels, we find that for3p localizes to small dots that appear transiently at cell tips and then move away on actin cables at a rate of 0.3 μm/s. These movements were dependent on the continuous assembly of actin in cables, on the ability of for3p to bind actin within its FH2 domain, and on profilin and bud6p, two formin binding proteins that promote formin activity. Bud6p transiently colocalizes with for3p at the cell tip and stays behind at the cell tip when for3p detaches.ConclusionsThese findings suggest a new model for actin cable assembly: a for3p particle is activated and promotes the assembly of a short actin filament at the cell tip for only seconds. For3p and the actin filament may then be released from the cell tip and carried passively into the cell interior by retrograde flow of actin filaments in the cable. These studies reveal a complex and dynamic cycle of formin regulation and actin cable assembly in vivo
Long-lasting insecticide-treated net usage in eastern Sierra Leone - the success of free distribution.
Summary Objective Médecins Sans Frontières (MSF) runs a malaria control project in Bo and Pujehun districts (population 158 000) that includes the mass distribution, routine delivery and demonstration of correct use of free, long-lasting insecticide-treated nets (LLINs). In 2006/2007, around 65 000 LLINs were distributed. The aim of this follow-up study was to measure LLIN usage and ownership in the project area. Methods Heads of 900 randomly selected households in 30 clusters were interviewed, using a standardized questionnaire, about household use of LLINs. The condition of any LLIN was physically assessed. Results Of the 900 households reported, 83.4% owning at least one LLIN. Of the 16.6% without an LLIN, 91.9% had not participated in the MSF mass distribution. In 94.1% of the households reporting LLINs, the nets were observed hanging correctly over the beds. Of the 1135 hanging LLINs, 75.2% had no holes or 10 or fewer finger-size holes. The most common source of LLINs was MSF (75.2%). Of the 4997 household members, 67.2% reported sleeping under an LLIN the night before the study, including 76.8% of children under 5 years and 73.0% of pregnant women. Conclusion Our results show that MSF achieved good usage with freely distributed LLINs. It is one of the few areas where results almost achieve the new targets set in 2005 by Roll Back Malaria to have at least 80% of pregnant women and children under 5 years using LLINs by 2010
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