Particles-vortex interactions and flow visualization in He4

Recent experiments have demonstrated a remarkable progress in implementing and use of the Particle Image Velocimetry (PIV) and particle tracking techniques for the study of turbulence in He4. However, an interpretation of the experimental data in the superfluid phase requires understanding how the motion of tracer particles is affected by the two components, the viscous normal fluid and the inviscid superfluid. Of a particular importance is the problem of particle interactions with quantized vortex lines which may not only strongly affect the particle motion, but, under certain conditions, may even trap particles on quantized vortex cores. The article reviews recent theoretical, numerical, and experimental results in this rapidly developing area of research, putting critically together recent results, and solving apparent inconsistencies. Also discussed is a closely related technique of detection of quantized vortices negative ion bubbles in He4.Comment: To appear in the J Low Temperature Physic

Fenologie, habitat en verspreiding van pluimmuggen in nederlandse hoogvenen (diptera: Chaoboridae)

Contains fulltext : 91816.pdf (publisher's version ) (Open Access)73 p

Changes in macroinvertebrate richness and diverity following large scale rewetting measures in a heterogeneous bog landscape.

Contains fulltext : 36045.pdf (publisher's version ) (Open Access)not availabl

New records of Odonata from Estonia, with notes on breeding in the Baltic sea and on species assemblages of raised bog systems.

Contains fulltext : 121867.pdf (publisher's version ) (Open Access

Metriocnemus carmencitabertarum, een nieuwe dansmug voor Nederland (Diptera: Chironomidae)

In augustus 2011 werd een larve van een dansmug gevonden in een emmer onder een dakgoot in Appingedam. Na uitkweken bleek het te gaan om Metriocnemus carmencitabertarum, een nieuwe soort voor Nederland. In het buitenland komt deze soort voor in met water gevulde natuurlijke kommen in rotsen en soortgelijke kunstmatige habitats als drinkbakken. Aan het eind van 2011 werden vrouwtjes dansmuggen gezien die hun eieren afzetten in dezelfde emmer. Dit gaf de unieke mogelijkheid om informatie over de biologie van deze mug te verzamelen

Data from: How to restore invertebrate diversity of degraded heathlands?

We tested whether increased P-limitation and/or acidification reduced food quality of plants after sod-cutting management by performing feeding experiments with the field cricket (Gryllus campestris), using food obtained from a field experiment in which we applied P and/or lime to sod-cut heathland. We show that increased plant N:P ratio following sod-cutting constrains the reproductive potential in Gryllus campestris. However, liming greatly reduced reproductive performance. Detailed analysis on elemental stoichiometry revealed skewed Fe:Mg and Mn:Mg ratio’s induced by liming, which diverge strongly from invertebrate ratios. The datafiles are part of a study that investigated the effects of methods aimed to restore P availability (reduced due to sod-cutting) and of reducing soil acidity (increased due to acid deposition) on heathland vegetation nutritional quality for invertebrates, using the field cricket Gryllus campestris (L.) as model species. This study was performed in the National Park the Hoge Veluwe (experimental plots) and the Radboud University Nijmegen (controlled feeding experiment) from April to July 2014. This dataset contains field cricket life history and reproduction measurements and plant tissue elemental content data results from the experiment. Additionally, two datafiles used in comparative analyses of plant vs invertebrate elemental ratios and in comparison of results from two feeding experiments, differing in food plant tissue N:P ratio are made available. Other datasets that were added are helper files explaining data type and files used for analysis and graphical representation. The full methodology can be found in the linked paper, the analyses used in the publication can be reviewed using the included R script

Do raised bog restoration measures rehabilitate aquatic fauna diversity? A comparative study between pristine, degraded, and rewetted raised bogs

Item does not contain fulltext12th International Peat Congress 2004 Tampere, Finland, 06 juni 200

Restoration of degraded raised bogs: do aquatic invertebrates tell a different story?

Contains fulltext : 176237.pdf (preprint version ) (Open Access)ICE Wetlands Conference, Talinn, Estonia, 30 juni 200

Important keys to successful restoration of characteristic aquatic macroinvertebrate fauna of raised bogs

Contains fulltext : 176145.pdf (publisher's version ) (Open Access)Pärnu 2002 Peat in Horticulture Symposium – IPS Commision V: Peatland restoratio