Field Measurements of Hanging Flight Aerodynamics in the Kestrel Falco Tinnunculus

Hunting kestrels were observed to hang, almost without wing-flapping, in fixed positions over a sea dike. The height and position with respect to the dike profile, the wind direction and velocity and the percentage of hunting time without wing beating were recorded in 429 cases. The vertical wind angle, theta, the wind speed and its horizontal direction were measured at 13 heights up to 8.8 m above the windward slope, the top and the leeward slope of the dike under various wind conditions in 225 cases. These wind profile measurements were used to estimate theta and wind speed near the hanging birds. Kestrels hanging more than 90 % of the hunting time preferred a position 6.5+/-1.5 m (S.D.) over the windward slope with sea winds blowing at 8.7+/-1.5 m s-1 (S.D.) perpendicular (+/-30 degrees) to the longitudinal dike axis. For these birds angle theta was approximately 6-7 degrees). These angles are larger than expected from aerodynamic models and wind-tunnel measurements. The minimum gliding angle for a kestrel under steady conditions is estimated to be 5 degrees. Hanging kestrels save two-thirds of the energy used during normal windhovering but have to spend 1.6 times more time to catch the same number of voles

Ouderenpsychiatrie:Translationele psychiatrie ten top!

Het thema van het NVvP voorjaarscongres dit jaar is ‘translationele psychiatrie’. Aansluitend aan dit thema schreef dr. Arjan Videler, psychotherapeut en onderzoeker op het gebied van persoonlijkheid & gedrag bij ouderen, het whitepaper ‘Ouderenpsychiatrie: translationele psychiatrie ten top!’. Van alle subspecialisaties van de psychiatrie, vereist de ouderenpsychiatrie als geen ander de vaardigheid om te ontrafelen en te vertalen. In dit whitepaper gaat Arjan Videler aan de hand van voorbeelden in op de verschillende vormen van translatie in de ouderenpsychiatri

Systems training for emotional predictability and problem solving in older adults with personality disorders:A pilot study

Background: Systems Training for Emotional Predictability and Problem Solving (STEPPS) is a cognitive behavioural therapy-based group treatment programme for patients with borderline personality disorder (BPD). STEPPS has demonstrated its effectiveness for (younger) adults. However, there are no studies into the effects of STEPPS for older adults. Aim: The aim was to explore the outcome of STEPPS in older adults with personality disorders. Method: In this naturalistic pre- vs post-treatment study, older patients with a personality disorder, reporting emotion regulation difficulties, were included. The primary outcome was BPD symptoms. Secondary outcomes included psychological distress and maladaptive personality functioning. Results: Twenty-four patients, with a mean age of 63.9 years (SD=4.6), completed the 19-week programme. Nine patients (23.1%) did not complete the treatment. There were no significant differences in age, gender or global severity between completers and patients dropping out. There was a significant pre- vs post-treatment decrease of BPD symptoms, with a large effect size (Cohen’s d=1.577). Self-control improved significantly and demonstrated a large effect size (r=.576). Furthermore, identity integration improved significantly, with a medium effect size (Cohen’s d=.509). No significant differences were reported for most domains of psychological distress and maladaptive interpersonal personality functioning. Conclusions: The findings in this pilot study suggest STEPPS is a feasible treatment programme for older adults with personality disorders and emotion regulation difficulties. Adaptations to the program, for a better fit for older adults, however, might be needed