De werking en het nut : het snelgrovebord

Bart Boersma vroeg de redactie om nadere informatie over het snelgrove- bord, dat gebruikt wordt bij het voorkomen van zwermen

De Veluwse maat der dingen: Gemengd bedrijf

Twee raammaten op de stand: dat is bijna nog erger dan een sigaret opsteken in een volle lift. Maar misschien valt er toch wel goed te imkeren met een ‘gemengd bedrijf’. Mederedacteur Bart de Coo spreekt van ‘de Veluwse maat’

Boekweit en bijen gemaakt voor elkaar

Toelichting over de rol van boekweit, vroeger en nu

De honingbakkenmethode : het halve werk

Imkers maken het allemaal wel eens mee: gedeeltelijk gevulde honingramen. De oplossing is om lage raampjes van honingkamerformaat te gebruiken. In ieder geval makkelijker te tillen. Maar dan zit men met twee raammaten op de stand en dat vindt lang niet iedereen leuk. Geen nood: de lage raampjes kunnen ook voor broedkamers worden gebruikt: de honingbakkenmethode

Bijengezondheidsdag: Bijen@wur 2018

Deze dag, alweer de zevende editie, stond in het teken van invasieve exoten, waarvan we er één helaas maar al te goed kennen

Drukbezochte Koninginnenteeltdag 2016 : selecteren van bijen op varroatolerantie

De zaal in Austerlitz zit met zo’n 170 personen dit jaar weer propvol. Er is een rijk geschakeerd programma gewijd aan de aanpak van selectie op varroa-tolerante bijen. Daarnaast komt koninginnenteelt voor de beginnende/kleine imker aan bod. Het programma van de Koninginnenteeltdag begint met een drieluik van Bijen@WUR over selectie op varroaresistentie

Electrostatic complexation of spheres and chains under elastic stress

We consider the complexation of highly charged semiflexible polyelectrolytes with oppositely charged macroions. On the basis of scaling arguments we discuss how the resulting complexes depend on the persistence length of the polyelectrolyte, the salt concentration, and the sizes and charges of the chain and the macroions. We study first the case of complexation with a single sphere and calculate the wrapping length of the chain. We then extend our considerations to complexes involving many wrapped spheres and study cooperative effects. The mechanical properties of such a complex under an external deformation are evaluated.Comment: 16 pages, submitted to J. Chem. Phy

A Fiber-Based Laser Ultrasonic System for Remote Inspection of Limited Access Components

Surface and plate waves are commonly used to nondestructively inspect the near-surface region of a solid component for cracks and other defects due to, for example, structural fatigue. One particularly attractive method of generating and detecting such ultrasonic signals is laser based ultrasonics (LBU) [1]. In particular, because it is non-contact (i.e., does not require couplant), LBU can be implemented for inspection of limited access components using optical fibers, requiring only a small cross-sectional area for access. An example can be found in the inspection of internal surfaces of an aircraft wing as shown in Figure 1 where a contact method would obviously be difficult to apply. Furthermore, in cases where extremely high sensitivity is required, bandwidth reduction can be employed by concentrating the laser generated signal into a narrow frequency band

ASAS/WHO ICF Core Sets for ankylosing spondylitis (AS): how to classify the impact of AS on functioning and health

Objective: To report on the results of a standardised consensus process agreeing on concepts typical and/or relevant when classifying functioning and health in patients with ankylosing spondylitis (AS) based on the International Classification of Functioning and Health (ICF).Methods: Experts in AS from different professional and geographical backgrounds attended a consensus conference and were divided into three working groups. Rheumatologists were selected from members of the Assessment of SpondyloArthritis international Society (ASAS). Other health professionals were recommended by ASAS members. The aim was to compose three working groups with five to seven participants to allow everybody's contribution in the discussions. Experts selected ICF categories that were considered typical and/or relevant for AS during a standardised consensus process by integrating evidence from preceding studies in alternating working group and plenary discussions. A Comprehensive ICF Core Set was selected for the comprehensive classification of functioning and a Brief ICF Core Set for application in trials.Results: The conference was attended by 19 experts from 12 countries. Eighty categories were included in the Comprehensive Core Set, which included 23 Body functions, 19 Body structures, 24 Activities and participation and 14 Environmental factors. Nineteen categories were selected for the Brief Core Set, which included 6 Body functions, 4 Body structures, 7 Activities and participation and 2 Environmental factors.Conclusion: The Comprehensive and Brief ICF Core Sets for AS are now available and aim to represent the external reference to define consequences of AS on functioning