Intestinal epithelial responses to Salmonella enterica serovar Enteritidis: Effects on intestinal permeability and ion transport

Salmonella infection of chickens that leads to potential human foodborne salmonellosis continues to be a major concern. Chickens serve as carriers but, in contrast to humans, rarely show any clinical signs including diarrhea. The present investigations aimed to elucidate whether the absence of diarrhea during acute Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) infection may be linked to specific changes in the electrophysiological properties of the chicken gut. Immediately after slaughter, intestinal pieces of the mid-jejunum and cecum of either commercial broiler or specific pathogen-free (SPF) chickens were mounted in Ussing chambers in 2 separate experimental series. Living Salmonella Enteritidis (3 × 109) or Salmonella Enteritidis endotoxin (20 mg/L), or both, were added to the mucosal side for 1 h. In both experimental series, the Salmonella infection decreased the trans-epithelial ion conductance Gt (P < 0.05). In the jejunum of SPF chickens, there was also a marked decrease in net charge transfer across the epithelium, evidenced by decreased short-circuit current (Isc, P < 0.05). Interestingly, the mucosal application of Salmonella endotoxin to the epithelial preparations from jejunum and cecum of SPF chicken had an effect similar to living bacteria. However, the endotoxin had no additional effect on the intestinal function in the presence of bacteria. The decreasing effect of Salmonella and or its endotoxin on Gt could be partly reversed by serosal addition of histamine. To our knowledge, this is the first study to address the functional response of native intestinal epithelium of chicken to an in vitro Salmonella infection. For the first time, it can be reported that intestinal ion permeability of chicken decreases acutely by the presence of Salmonella. This type of response could counteract ion and fluid secretion and may thus, at least in part, explain why chickens do not develop overt diarrhea after Salmonella infection

Campylobacter jejuni colonization promotes the translocation of Escherichia coli to extra-intestinal organs and disturbs the short-chain fatty acids profiles in the chicken gut

For a long time Campylobacter was only considered as a commensal microorganism in avian hosts restricted to the ceca, without any pathogenic features. The precise reasons for the symptomless chicken carriers are still unknown, but investigations of the gastrointestinal ecology of broiler chickens may improve our understanding of the microbial interactions with the host. Therefore, the current studies were conducted to investigate the effects of Campylobacter jejuni colonization on Escherichia coli translocation and on the metabolic end products (short-chain fatty acids, SCFAs). Following oral infection of 14 day old broiler chickens with 1 × 108 CFU of Campylobacter jejuni NCTC 12744 in two independent animal trials, it was found that C. jejuni heavily colonized the intestine and disseminate to extra-intestinal organs. Moreover, in both animal trials, the findings revealed that C. jejuni promoted the translocation of E. coli with a higher number encountered in the spleen and liver at 14 days post infection (dpi). In addition, Campylobacter affected the microbial fermentation in the gastrointestinal tract of broilers by reducing the amount of propionate, isovalerate, and isobutyrate in the cecal digesta of the infected birds at 2 dpi and, at 7 and 14 dpi, butyrate, isobutyrate, and isovalerate were also decreased. However, in the jejunum, the C. jejuni infection lowered only butyrate concentrations at 14 dpi. These data indicated that C. jejuni may utilize SCFAs as carbon sources to promote its colonization in the chicken gut, suggesting that Campylobacter cannot only alter gut colonization dynamics but might also influence physiological processes due to altered microbial metabolite profiles. Finally, the results demonstrated that C. jejuni can cross the intestinal epithelial barrier and facilitates the translocation of Campylobacter itself as well as of other enteric microorganisms such as E. coli to extra-intestinal organs of infected birds. Altogether, our findings suggest that the Campylobacter carrier state in chicken is characterised by multiple changes in the intestinal barrier function, which supports multiplication and survival within the host

Ash grains of the 1991 Mt. Pinatubo eruption as a tracer in Rose Bengal stained deep sea agglutinated foraminifera: How old is Freddy?

The use of volcanic ash particles (including dark-coloured grains) by agglutinated foraminifera that survived the 1991 eruption of Mt Pinatubo volcano provides a useful tracer to help determine growth rates and longevity in the deep sea. In the case of a specimen of Cyclammina pusilla Brady, the rate of chamber addition in this Rose Bengal stained sub-adult individual is three chambers over a timespan of five and one-half years

Netzliteratur - ein neues Genre?

In den Text-, Kommunikations- und Medienwissenschaften gewinnt in jüngster Zeit ein Thema an Resonanz, das von den Medien selbst längst schon vorgegeben wurde: Sprachwandel im Zeichen des Medienwandels. Den damit einhergehenden und teilweise wohl auch dadurch bedingten Veränderungen in den Gepflogenheiten unseres kommunikativen Gebarens im Alltag gilt daher, beispielsweise, das Interesse der Beiträge zu dem Sammelband Medien, Texte und Maschinen, der die ersten Umrisse einer zu entwickelnden Angewandten Mediensemiotik zu zeichnen strebt. Zu ihren Aufgaben gehören freilich nicht nur die Sichtung der dort vorgestellten theoretischen Ansätze, terminologischen Vereinbarungen, methodischen Instrumentarien, nicht nur die Beobachtung der Konsequenzen technischer Innovationen für den Umgang mit den gewohnten Ressourcen täglicher Information, nicht nur die Analyse der neuartigen Gestalt polycodierter Texte und ihrer Funktionen in Bildung und Wissenschaft, nicht nur die Rekonstruktion von Entwicklungslinien traditioneller Medien etwa der Presse oder der Werbung im Übergang vom Industrie- zum Informationszeitalter, nicht nur die Veranschaulichung versprachlichter Gehalte in anderen Codes, nicht nur die Entfaltung von Perspektiven des Wissenstransfers durch Computervisualistik oder der Sinnkonstruktion an den modernen Maschinen der Kommunikation. Im Folgenden sollen einige Anregungen zusammengefasst und weitergeführt werden, den sog. neuen Genres germanistische Neugier zu widmen: Netzliteratur, Hyperfiction, Computeranimation im Film, Bildschirmästhetik im Fernsehen, Interface- und Textdesign und E-Book-Roman, denn all dies erfordert neue Lektüre- Modelle, zu deren Entwurf und theoretischer Grundlegung es einer textwissenschaftlich systematischen Erforschung bedarf der vielfältigen und sich wechselseitig befruchtenden Formen künstlerischen Ausdrucks in allen Medien und über die kulturellen Grenzen hinweg.Discourse studies have recently turned their attention to changes in language use caused by changes in the media environment. They analyse, for instance, the impact of technical innovation on the resources of daily information, the new design of poly-coded texts and their functions in science and education, the development of traditional media such as press or television from the age of industry to that of digital information, the visualisation of linguistic content in other codes, the transfer of knowledge and production of meaning with modern machines of communication. But among their manifold interests is also the aesthetic dimension of semiotic change influenced by the typological expansion and technological innovation of the media system as a whole. The role of the author is put into question, when looking at new forms of literary production on computer screens. The automat defines the textual structure of their works, which they create jointly in the net. Routines of perception will change audio-visual structures of literature competing with film, television, video, hypertext. The project of media aesthetics will be complemented by a yet to be drafted tele-semiotics of audio-visual media and digital art. This paper aims to take a closer look at new genres of aesthetics: net literature, hyperfiction, computer animation in film, interface design of video games, electronic novel, etc. They ask for new models of reading, which are to be designed and investigated with new methods of textual analysis and comparative tools across all the media of aesthetic expression and across all cultures of verbal art

Interkulturelle Medienwissenschaft und Kulturkonflikt

The paper attempts a combination of intercultural studies and media studies. It first provides a terminological framework for the analysis of intercultural communication. Secondly, it gives a short outline of current research in the field of intercultural media studies, with special reference to the press and to television. It then opens up a perspective of empirical investigation into forms and functions of the depiction of ethnic minorities in the media, of implicit racism and hidden forms of discrimination in the news broadcasting, and of the image of foreigners in contemporary film. The main part of the paper is, on the one hand, devoted to the observation of the presence of foreigners in German TV programmes and the ways they are treated in with in various formats of broadcasting. On the other hand, it takes a closer look at the role of media for ethnic minorities, whether or not they serve a policy of integration and how the minorities make use of their own newspapers and television programmes. In a concluding paragraph a new field of research within intercultural media studies is outlined: development communication and eco-semiotics. Here, intercultural, institutional, and interpersonal communication processes merge in sustainable instruction procedures for the implementation of knowledge relevant for technology, environment and health in so-called low income countries

Urban discourse – city space, city language, city planning: Eco-semiotic approaches to the discourse analysis of urban renewal

Sustainable Urban Planning has to be understood as a communicative process connecting city architecture, technology, city district management and social infrastructure of neighbourhoods. The focus on sustainability raises the question of the necessary discourse conditions that allow architects and city planners enter into a dialogue with other urban stakeholders, citizens, local administrators and politicians, and discuss which cultural heritage should be preserved and where sustainability takes precedence. Looking at the style of discourse in urban communication brings also its socio-cultural modalities into focus. At the intersection of communication and discourse studies, urban ecology and sociology, the article focuses on the growing interest in architectural communication and, taking current approaches as a starting point, seeks to clarify which conversational maxims and discourse requirements by mediation, moderation, and integration are promising for achieving a new urban quality