Social-perspective coordination and gifted adolescents’ friendship quality

This research examined links among academic ability, social-perspective coordination, and friendship quality, within the context of gifted adolescents’ friendships. The sample consisted of 120 early adolescents (59 girls, 61 boys), 81 of whom were identified as gifted. Academic ability, sex, and grade significantly predicted social-perspective coordination (an indicator of psychosocial maturity) in multiple regression analyses. Social-perspective coordination, perceptions (self-concept) of ability to make and keep friends, academic ability, sex, and grade predicted perceptions of the overall quality of friendships. Being a female, seventh grader, or adolescent not identified as gifted, significantly predicted higher friendship quality. Social-perspective coordination and self-concept based on having a close friend predicted higher levels of friendship quality for the gifted participants.     

Simulation and experimental determination of the online separation of blood components with the help of microfluidic cascading spirals

Microfluidic spirals were used to successfully separate rare solid components from unpretreated human whole blood samples. The measured separation ratio of the spirals is the factor by which the concentration of the rare component is increased due to the Dean effect present in a flow profile in a curved duct. Different rates of dilution of the blood samples with a phosphate-buffered solution were investigated. The diameters of the spherical particles to separate ranged from 2 μm to 18 μm. It was found that diluting the blood to 20% is optimal leading to a separation ratio up to 1.97. Using two spirals continuously placed in a row led to an increase in separation efficacy in samples consisting of phosphate-buffered solution only from 1.86 to 3.79. Numerical investigations were carried out to display the flow profiles of Newtonian water samples and the shear-thinning blood samples in the cross-section of the experimentally handled channels. A macroscopic difference in velocity between the two rheologically different fluids could not be found. The macroscopic Dean flow is equally present and useful to help particles migrate to certain equilibrium positions in blood as well as lower viscous Newtonian fluids. The investigations highlight the potential for using highly concentrated, very heterogeneous, and non-Newtonian fluidic systems in known microsystems for screening applications.     

A remotely operated drug delivery system with an electrolytic pump and a thermo-responsive valve

Implantable drug delivery devices are becoming attractive due to their abilities of targeted and controlled dose release. Currently, two important issues are functional lifetime and non-controlled drug diffusion. In this work, we present a drug delivery device combining an electrolytic pump and a thermo-responsive valve, which are both remotely controlled by an electromagnetic field (40.5 mT and 450 kHz). Our proposed device exhibits a novel operation mechanism for long-term therapeutic treatments using a solid drug in reservoir approach. Our device also prevents undesired drug liquid diffusions. When the electromagnetic field is on, the electrolysis-induced bubble drives the drug liquid towards the Poly (N-Isopropylacrylamide) (PNIPAM) valve that consists of PNIPAM and iron micro-particles. The heat generated by the iron micro-particles causes the PNIPAM to shrink, resulting in an open valve. When the electromagnetic field is turned off, the PNIPAM starts to swell. In the meantime, the bubbles are catalytically recombined into water, reducing the pressure inside the pumping chamber, which leads to the refilling of the fresh liquid from outside the device. A catalytic reformer is included, allowing more liquid refilling during the limited valve''s closing time. The amount of body liquid that refills the drug reservoir can further dissolve the solid drug, forming a reproducible drug solution for the next dose. By repeatedly turning on and off the electromagnetic field, the drug dose can be cyclically released, and the exit port of the device is effectively controlled.     

Anorexia athletica in pre-professional ballet dancers

Competitive sport has been under increasing discussion as a possible favourable factor in the development of eating disorders among children and adolescents. The aim of this study was to determine the frequency of sport-specific eating disorders, in line with the concept of anorexia athletica. This prospective field study included one experimental group and two control groups (disease and healthy). Fifty-two pre-professional ballet dancers aged 13-20 years were tested for clinical eating disorders, anorexia athletica criteria, eating disorder related psychopathology and self-concept, and were compared with 52 patients with anorexia nervosa and 44 non-athletic controls of the same age. The study was conducted using semi-structured interviews as well as self-report questionnaires. A clinical eating disorder diagnosis was made in 1.9% of the ballet dancers versus 0% of the high school students; anorexia athletica was diagnosed in 5.8% of the dancers versus 2.3% of the students. Ballet dancers scored lower than patients with anorexia nervosa with regard to eating disorder related psychopathology and higher than the patients with regard to self-concept. We conclude that more sensitive tools to differentiate between sport-specific (eating) patterns, anorexia athletica and clinically relevant eating disorders are needed, especially for aesthetic sports such as ballet. It remains an important goal to identify athletes with symptoms of anorexia athletica irrespective of their physique and/or sport.     

Testing Measurement Equivalence of Eudaimonic and Hedonic Entertainment Motivations in a Cross-cultural Comparison

Within Hofstede’s framework of individualistic and collectivistic cultures, this contribution examines measurement equivalence of hedonic and eudaimonic entertainment motivations in two different cultures, namely Germany representing a more individualistic culture (N = 180) and Turkey representing a more collectivistic culture (N = 97). By means of a multi-group confirmatory factor analysis, we could secure configural invariance for both hedonic and eudaimonic entertainment motivations across the German and Turkish sample. Metric invariance, however, could only be obtained for hedonic, but not for eudaimonic motivations. Scalar invariance was obtained for neither of the two entertainment motivations. The study points to the importance of equivalence testing when conducting cross-cultural research.