A Systems Theory Perspective

Aktualisierung: Am 12. Oktober 2018 wurde die digitale Version des Buchbeitrags um den fehlenden Teil (Seiten 53-66) ergänzt

Kinder online 2004 : Internetnutzung von Kindern ; Studie der Agentur für neue Medien NEUE DIGITALE in Zusammenarbeit mit dem Frankfurter Kinderbüro und der Johannes Gutenberg-Universität Mainz

Die Studie „Kinder Online 2004“ soll Aufschluss darüber geben, wie Kinder heute den Computer und das Internet in ihrer Freizeit nutzen: den Stellenwert der digitalen Medien identifizieren und über das Internet-Verhalten der Kinder sowie über ihre Präferenzen informieren

Prey Resource Utilization by Coexistent Hydromedusae from Friday Harbor, Washington, USA

Prey selection patterns were quantified for a sympatric group of hydromedusae from Friday Harbor, WA. Selection patterns varied between species, but were largely replicable between sample dates and resembled dietary patterns found in similar studies from neighboring regions. Ambush-foraging medusae (Aglantha digitale, Sarsia tubulosa, and Proboscidactyla flavicirrata) fed primarily on crustacean and ciliated prey but the dietary niches of these hydromedusan species centered on different fractions of the available plankton. Consequently, little dietary overlap occurred between the ambush foraging hydromedusae. In contrast, the dietary niches of cruising predators (Aequorea victoria, Mitrocoma cellularia, and Phialidium gregarium) overlapped substantially because those species all fed on similar soft-bodied prey such as eggs and appendicularians. These results have two important implications for trophic patterns involving medusae. First, different mechanisms of prey encounter and capture used by hydromedusae (ambush vs. cruising patterns) result in important interspecific dietary differences and, hence, trophic roles of the medusae. Second, whereas cruising medusae may consume similar prey and hence form a feeding guild, ambush-foraging medusae may experience substantially less prey overlap and, for the community examined here, do not experience potentially strong feeding competition from other medusan species

Morphology, Swimming Performance and Propulsive Mode of Six Co-occurring Hydromedusae

Jet propulsion, based on examples from the Hydrozoa, has served as a valuable model for swimming by medusae. However, cnidarian medusae span several taxonomic classes (collectively known as the Medusazoa) and represent a diverse array of morphologies and swimming styles. Does one mode of propulsion appropriately describe swimming by all medusae? This study examined a group of co-occurring hydromedusae collected from the waters of Friday Harbor, WA, USA, to investigate relationships between swimming performance and underlying mechanisms of thrust production. The six species examined encompassed a wide range of bell morphologies and swimming habits. Swimming performance (measured as swimming acceleration and velocity) varied widely among the species and was positively correlated with bell streamlining (measured as bell fineness ratio) and velar structure development (measured as velar aperture ratio). Calculated thrust production due to jet propulsion adequately explained acceleration patterns of prolate medusae (Aglantha digitale, Sarsia sp. and Proboscidactyla flavicirrata) possessing well-developed velums. However, acceleration patterns of oblate medusae (Aequorea victoria, Mitrocoma cellularia and Phialidium gregarium) that have less developed velums were poorly described by jet thrust production. An examination of the wakes behind swimming medusae indicated that, in contrast to the clearly defined jet structures produced by prolate species, oblate medusae did not produce defined jets but instead produced prominent vortices at the bell margins. These vortices are consistent with a predominantly drag-based, rowing mode of propulsion by the oblate species. These patterns of propulsive mechanics and swimming performance relate to the role played by swimming in the foraging ecology of each medusa. These patterns appear to extend beyond hydromedusae and thus have important implications for other members of the Medusazoa

The canonization of German-language digital literature

In his paper, "The Canonization of German-language Digital Literature," Florian Hartling discusses "Net Literature," a relatively young phenomenon, that has its roots in experimental visual and concrete poetry and hypertext. With the use of new media technology, this new genre of literature has acquired much interest and is now considered to be one of the most important influences in contemporary art. Not only does Net Literature connect sound, video, and animation with interactivity and allows new forms of artistic expression, it also impacts significantly on the traditional functions of the literary system. Hartling suggests that, in relation to Net Literature, the notion of the "death of the author" gives birth to the "writing reader." Hartling presents the results of his study where he applies the concept of "canon" to German-language Net Literature and where he attempts to find out whether, in this new form of literature, a "canon" has already been formed. Based on Karl Erik Rosengren's framework of "mention technique," a sample of Germanlanguage reviews of Net Literature was analyzed. The study intends to test the applicability of Rosengren's method to the analysis of Net Literature, that is, whether it is valid to use a method that was originally developed for the empirical study of the traditional literary canon for the study of an emergent Net Literature

Meerdere schermen in de huiskamer: een onderzoek naar simultaan mediagebruik

Today’s (home) media environment is becoming increasingly saturated. Smartphones, tablets and laptops enter our living rooms and possibly alter our television viewing experience. In this paper, we want to grasp to what extent the use and role of television changes in the presence of multiple mobile media technologies. Through a multi-method approach we explore TV viewing behavior in a media-rich living room. Survey results indicate that the ownership of multiple media technologies in the home environment promotes their use whilst watching television. In addition, in-depth interviews reveal that in these media-rich living rooms media consumption becomes both more individualized and more social. According to the interviewees, social interaction within the living room has not decreased, but rather complemented with online conversations. These conversations can be in accordance (or congruent) with television content, but most of the time they are unrelated (or incongruent)