Synchronization theory for forced oscillations in second-order systems

We consider differential equations of the form x¨+∈f(x,x˙)+x=∈u, where ε>0 is supposed to be small. For piecewise continuous controlsu(t), satisfying |u(t)|≤1, we present sufficient conditions for the existence of 2π-periodic solutions with a given amplitude. We present a method for determining the limiting behavior of controlsūε for which the equation has a 2π-periodic solution with a maximum amplitude and for determining the limit of this maximum amplitude as ε tends to zero. The results are applied to the linear system x¨+∈x˙+x=∈u, the Duffing equation x¨+∈(x−1)x˙+x=∈u, and the Van der Pol equation x¨+∈(x2−1)x˙+x=∈u

[Professional caregivers as civilian first responders in prehospital cardiac arrest]

The chance of survival from a prehospital cardiac arrest has increased enormously in recent years thanks to the efforts of civilian first responders. They can start CPR and possibly defibrillate while waiting for the ambulance. These civilian first responders regularly include professional caregivers who can provide advanced life support (ALS) together with ambulance personnel. This article describes the opportunities and challenges, and discusses competence and ability, the use of expertise, and crew resource management (CRM) to ensure that the available knowledge and skills are managed in the right direction. This can further improve the quality of patient care and thus increase the chance of survival

[Cross-border healthcare: EU citizens as patients].

With the free movement of people within the European Union (EU), it occurs that EU citizens need healthcare in and different country, other than their country of origin. Identification of patients is important, and the EU is currently implementing a digital Patient Summary to provide physicians with essential information concerning an European patient. Physicians should be aware that the obligation concerning informed consent carries extra weight for patients with a language barrier. A professional interpreter can facilitate bridging this linguistic barrier. All patients who die within the Netherlands are subject to Dutch legislation on organ donation. The reimbursement of care is regulated within the EU by Regulations (No 883/2004 and No 987/2009) and the Directive on the application of patients' rights in cross-border healthcare. In principle, unplanned care is always reimbursed, whereas planned clinical care requires permission from the patient's health insurer