Practice makes perfect: The longitudinal effect of adolescents’ instant messaging on their ability to initiate offline friendships

The first aim of this study was to investigate whether instant messaging (IM) influences adolescents’ ability to initiate offline friendships. The second aim was to study the validity of two underlying mechanisms that may account for this relationship: (a) the opportunities offered by IM to communicate with a variety of people, and (b) to disclose intimate information. A three-wave longitudinal study was conducted among 690 Dutch adolescents (10–17 years old). Results show that adolescents’ IM use increased their ability to initiate offline friendships over time. Furthermore, IM use indirectly increased adolescents’ ability to initiate offline friendships through the diversity of their online communication partners. These findings suggest that adolescents can practice social skills online and learn to relate to a variety of people, which, over time, may increase their ability to initiate offline friendships.     

Employing ai methods to control the behavior of animated interface agents

Life - like characters are increasingly gaining the attention of researchers and commercial developers of user interfaces . A strong argument in favor of using such characters in the interface is the rich repertoire of options they offer , enabling the emulation of communication styles common in human - human dialog . This contribution presents a framework for the development of presentation agents , which can be used for a broad range of applications including personalized information delivery fromthe WWW .     

Rechtliche Verbotsvorschläge der ärztlichen Unterstützung bei der Selbsttötung von schwerkranken Patienten

Definition of the problem In the current ethical debate on physician-assisted suicide in Germany new sanctions in criminal law are debated from different sides. Whereas in the beginning the debate focused only on the ban of organised forms of suicide assistance, the explicit licensing of assisted suicide is also now requested by physicians. Arguments Considering the approach to include prohibition of assisted suicide within the German Criminal Code, the article shows that the impunity of suicide and suicide assistance has a long tradition in Germany. The impunity of assisted suicide cannot only be systematically and factually justified, but also in terms of content. A criminalization can be neither legally nor ethically justified. Conclusion The authors advocate—with reference to different legal drafts in the German Federal Parliament (Deutscher Bundestag)—for an open discourse within the medical profession and for a revision of the professional law.     

Vorausverfügte Therapieablehnungen in Situationen von Eigen- oder Fremdgefährdung. Ethische und rechtliche Überlegungen zur Umsetzung von Patientenverfügungen in der Psychiatrie

Definition of the problem

In case of court-ordered involuntary hospitalization due to danger to self or to others psychiatric advance directives can lead to clinically and ethically challenging situations – especially when they contain (total) treatment refusals. In such situations, patients can neither be discharged from hospital nor medically treated.

Arguments

This article discusses ethical challenges in the context of advance treatment refusals from an interdisciplinary perspective. We outline legal limitations of advance directives and normative preconditions of valid advance directives (such as mental capacity at the time of composition, applicability to the current life and health situation) and analyse them with regard to clinical practice. Hence, we elaborate on ethical arguments for and against the conduction of coercive measures and coercive treatments in situations of danger to self or to others. By identifying normatively relevant aspects, our paper further contributes to the objective of ethically justified clinical decision-making in the context of advance treatment refusals.

Conclusion

Finally, we summarize implications for clinical practice that follow from the legal authority of advance directives. On a general level, we discuss ethical tensions resulting from psychiatry’s legal obligation to intervene in situations of danger to self or to others in the context of advance treatment refusals. On the level of the individual physician-patient relationship, we outline professional offers for consultation. Further, we reflect on their potential to better inform patients about possible far-reaching consequences (total) advance treatment refusals could entail.

     

Flow properties of thermally insulating powders under different atmospheric conditions

We determined the flow properties of powders used as thermal insulative materials at different temperatures, pressures and moisture conditions. The powders used in this study, SiO₂-aerogel, precipitated and fumed silica, have primary particle sizes ranging from a few nanometers to hundred micrometers. Due to the porosity of the particles and/or their large interparticular forces compared to their weight, the powders have very low densities (about 100 kg/m³). Therefore they display very small solid thermal conductivities in the order of 1 to 2 · 10^х W/(m K) and thus are promising as evacuated thermal insulants. In addition these powders are resilent to external loads. A prerequisite for the use of these powders in technical applications is the determination of their flow properties. For this purpose the powder samples were filled into a stainless steel hopper and the flow rate through the bottom opening was measured using a balance. Simultaneously, the resulting angle of repose was determined. The hopper can be heated up to 200^°C to remove adsorbed water and gases from the inner surface of the powder. The measuring device was mounted into a vacuum chamber in order to determine the influence of atmospheric humidity or gas pressure (pressure variation from 30 to 10⁵ Pa).     

Wie sollten Ärzte mit Patientenverfügungen umgehen? Ein Vorschlag aus interdisziplinärer Sicht

Ohne Zusammenfassung     

Yield Improvement and Advanced Defect Control——Driving Forces for Modeling of Bulk Crystal Growth

Yield improvement and advanced defect control can be identified as the driving forces for modeling of industrial bulk crystal growth. Yield improvement is mainly achieved by upscaling of the whole crystal growth apparatus and increased processing windows with more tolerances for parameter variations. Advanced defect control means on one hand a reduction of the number of deficient crystal defects and on the other hand the formation of beneficial crystal defects with a uniform distribution and well defined concentrations in the whole crystal. This "defect engineering" relates to the whole crystal growth process as well as the following cooling and optional annealing processes, respectively. These topics were illustrated in the paper by examples of modeling and experimental results of bulk growth of silicon (Si), gallium arsenide (GaAs), indium phosphide (InP) and calcium fluoride (CaF2). These examples also involve the state of the art of modeling of the most important melt growth techniques, crystal pulling (Czochralski methods) and vertical gradient freeze (Bridgman-type methods).     

Adolescents' Exposure to Sexually Explicit Online Material and Recreational Attitudes Toward Sex

Previous research has largely ignored the implications of adolescents' exposure to sexually explicit online material for their sexual attitude formation. To study whether adolescents' exposure to sexually explicit material on the Internet is related to recreational attitudes toward sex, we conducted an online survey among 471 Dutch adolescents aged 13–18. In line with an orientation 1 – stimulus – orientation 2 – response (O₁-S-O₂-R) model, we found a pattern of multiple mediated relationships. Male adolescents (O₁) used sexually explicit online material (S) more than female adolescents, which led to a greater perceived realism of such material (O₂). Perceived realism (O₂), in turn, mediated the relationship between exposure to sexually explicit online material (S) and recreational attitudes toward sex (R). Exposure to sexually explicit online material, then, is related to more recreational attitudes toward sex, but this relationship is influenced by adolescents' gender and mediated by the extent to which they perceive online sexual material as realistic.