1,779 research outputs found
Naar een duurzaam beheer van de aal in Nederland?
Het gaat al decennia lang erg slecht met de aal en de aal-visserij in Nederland en de rest van Europa. De Europese Unie heeft daarom besloten tot een Herstelprogramma. In dit kader moet Nederland voor het eind van dit jaar een beheersplan maken. Dit artikel geeft een samenvatting van de achtergronden, de resultaten van recent onderzoek en de mogelijkheden voor bescherming
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Session E2: Downstream Migration of 2+ Salmon Smolts (Salmo Salar) in the River Meuse in the Netherlands
Abstract:
Downstream migration of 2+ salmon smolts (Salmo salar) was studied in the Meuse in the Netherlands, in the period 2009-2013. Smolts (n =897) with implanted NEDAP transponders, were released at different locations in the lower part of the Meuse in Belgium (Berwijn, Moelingen) and the upper part of the Meuse in the Netherlands (Stevensweert, Linne), and tracked by NEDAP trail stations at 41 fixed locations distributed along the Meuse and the Berwijn to the North sea (distance more than 300 km). Over the period 2009-2013 70% (n =628) of the smolts were detected. Numbers of smolts reaching the North sea varied per year, with a minimum of 0% and a maximum of 15% of the detected fish. The route prevailingly used to migrated to sea by way of the Haringvliet. Duration of smolt migration was mostly less than one month, with average migration speeds always below 1.2 m/s. The influence of the hydro power station (HPS) Linne on the migration was examined. Yearly mortality per km of smolts, over the river stretch Linne – Lith (130 km) turned out to be higher especially in a short distance downstream of the HPS, indicating a vulnerability of the species which is higher for passing the hydropower station than for passing the weir. Also attention was paid on losses by predation of Cormorants
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Session C5: Downstream Migration of Silver Eel (Anguilla Anguilla) in the River Meuse in the Netherlands 2008 – 2012
Abstract:
Downstream migration of European silver eel (Anguilla anguilla) was studied in the Meuse in the Netherlands, in the period 2008-2012. Silver eel (n = 840), with implanted NEDAP transponders, were released at different locations, in the lower part of the Meuse in Belgium (Berwijn at Moelingen) and in the upper part of the Meuse in the Netherlands (Ohé en Laak). Fish were tracked by telemetry at 41 fixed NEDAP Trail detection stations distributed along the Meuse from the confluence with the Berwijn to the North sea, a distance of more than 330 km. Over the period 2008- 2013 75% (n = 630) of the eels were detected. Eel numbers reaching the North sea varied between 6-10% yearly. Most eels migrated to sea by way of the Haringvliet. Silver eel migration showed much individual variation, with fish reaching the sea within several days after being released and fish postponing their downstream migration for more than one year. The onset of migration was stimulated by increasing river discharge. Fish from different maturation classes showed no significant differences in migration speeds. Average individual migrations speed ranged from 0,3 to 1,6 m/s, indicative for at least a partly active migration (average river flow being 1 m/s). Generally migration speed slowed when fish approached sluices and weirs in the Meuse. The influence of the hydro power station (HPS) Linne on the migration was examined. Mortality of silver eel per kilometre, over the river stretch Linne – Lith (130 km) turned out to be twice as high after fish had passed the HPS (0,43% versus 0,22% passing the weir at the same location)
Fibre intake among the Belgian population by sex-age and sex-education groups and its association with BMI and waist circumference
The objectives of the present study were to assess total dietary fibre intake and the main contributors to fibre intake in the Belgian population by sex-age and sex-education groups and to investigate its relationship with BMI and waist circumference (WC). The participants of the Belgian food consumption survey (2004) were randomly selected. Information about food intake was collected using two repeated, non-consecutive 24 h recall interviews. A total of 3083 individuals (>= 15 years; 1546 men and 1537 women) completed both interviews. The main contributors to total fibre intake (17.8 g/d) were cereals and cereal products (34%; 5.9 g/d), potatoes and other tubers (18.6%; 3.3 g/d), fruits (14.7%; 2.8 g/d) and vegetables (14.4%; 2.6 g/d). Legume fibre intake was extremely low (0.672%; 0.139 g/d). In all sex-age and sex-education groups, total fibre intake was below the recommendations of the Belgian Superior Health Council. Men (21 g/d) consumed significantly more fibre than women (17.3 g/d) (P < 0.001). Lower educated men and higher educated women reported the highest fibre intake. A significant inverse association was found between total fibre intake and WC (beta = -0.118, P < 0.001). Fruit-derived fibre was positively associated with WC (beta = 0.731, P=0.001). In summary, total fibre intake was inversely associated with WC, whereas fruit-derived fibre intake was positively associated with WC in the Belgian population
Pharmacological strategies for manipulating plant Ca2+ signalling
Calcium is one of the most pleiotropic second messengers in all living organisms. However, signalling specificity is encoded via spatio-temporally regulated signatures that act with surgical precision to elicit highly specific cellular responses. How this is brought about remains a big challenge in the plant field, in part due to a lack of specific tools to manipulate/interrogate the plant Ca2+ toolkit. In many cases, researchers resort to tools that were optimized in animal cells. However, the obviously large evolutionary distance between plants and animals implies that there is a good chance observed effects may not be specific to the intended plant target. Here, we provide an overview of pharmacological strategies that are commonly used to activate or inhibit plant Ca2+ signalling. We focus on highlighting modes of action where possible, and warn for potential pitfalls. Together, this review aims at guiding plant researchers through the Ca2+ pharmacology swamp
Dans les cuisines créoles de Patrick Chamoiseau, la prodigieuse nourriture de survie
En s’attachant à l’œuvre romanesque de Patrick Chamoiseau, cet article étudie le motif de de la nourriture dans une double perspective. Il s’agit d’une part de comprendre en quoi l’alimentation constitue un enjeu identitaire et s’inscrit en tant que tel dans un rapport de force (post)colonial. La représentation de la nourriture semble d’autre part inviter le lecteur à reconsidérer sa relation à la littérature. Le parallélisme entre l’acte littéraire et l’alimentation renvoie alors à un double projet, à la fois politique et poétique. This papers analyzes the theme of food in Patrick Chamoiseau’s novels through two perspectives. On the one hand, the goal is to inderstand in what way food is used to build a specific identity and therefore is part of a (post)colonial power relationship. One the other hand, food seems to be used to entice the reader to rethink their relationship to literature. Parallels between literature and food take place in a political and poetical act
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