Die Organisation gemeinsamer Wissensproduktion im Internet

Die kooperative Entwicklung und Produktion freier/offener Computersoftware im Internet ist ein noch recht junges, aber von der Öffentlichkeit zunehmend beachtetes Phänomen sozialer Wissensproduktion. Unter dem Label „Free Software“ und „Open Source“ schließen sich global verteilte Akteure in einer Vielzahl von Projekten zusammen und widmen sich auf unbezahlter, freiwilliger Basis der gemeinsamen Herstellung von Software. Ihre Zusammenarbeit, meist ausschließlich über schriftliche Kommunikation koordiniert, folgt dabei den Maximen des unbeschränkten Austausches von Informationen und der Einbindung jedes Interessierten. Die vorliegende explorative Fallanalyse untersucht vor diesem Hintergrund die organisationalen Strukturen und Prozesse eines Projekts der freien/offenen Softwareentwicklung, um diese unter dem Aspekt sozialer Ordnungsleistung einem grundlegenden Verständnis zugänglich zu machen. In Rückgriff auf die bestehende Forschung wird zunächst das gesellschaftliche Feld freier/offener Softwareentwicklung als kontextualer Rahmen des kooperativen Zusammenschlusses erarbeitet und dargestellt. Darauf aufbauend folgt die Analyse der sozialen Organisationsformen eines ausgewählten Projektes anhand der exemplarischen Artefaktanalyse eines virtuellen Kommunikationstools und der Beziehungsstrukturen des Kommunikationsnetzwerkes des Projektes auf der Internetplattform sourceforge.net. Die Ergebnisse werden aus einer systemtheoretischen Perspektive schrittweise zusammengefasst und interpretiert. Die Fallanalyse zeigt eine grundlegende soziale Abgrenzung von Entwicklern und Anwendern (Leistungs- und Publikumsrolle), die sich in einem ausgeprägten Zentrum-Peripherie-Verhältnis organisieren. Ihre Kooperation realisiert sich in Form einer stark sachlich strukturierten Systemdifferenzierung, vor deren Hintergrund sich als emergentes Ordnungsprinzip eine abstrahierende Zwecksetzung bzw. ―programmierung freier/offener Softwareentwicklung rekonstruieren und zu einem funktionalen Verständnis der System- und Relationsausprägungen heranziehen lässt. Die Ergebnisse ermöglichen wesentliche Einsichten in die organisationalen Strategien gemeinsamer Wissensproduktion im Internet.The cooperative development and production of free/open computer software on the internet is a relatively recent, but public acclaimed phenomenon of social production of knowledge. Under the label of “free software” and “open source” global distributed actors are involved in projects and devote themselves to the production of software on an unpaid, voluntary basis. Their cooperation coordinates (mostly) exclusively through written communication and follows the maxims of open access to and unlimited exchange of information as well as the integration of each person interested. This case analysis examines the organizational structures and processes of a free/open software project to allow a fundamentally understanding under the aspect of social order. With recourse to existing research, at first the social field of free/open software development will be elaborated and presented as a contextual framework of the cooperative mergers. Based on this, the social organization of a project on the internet platform sourceforge.net will be analyzed by means of virtual communication tools and the structure of relationship of the communication network. The results are gradually summarized and interpreted from a social systems theory perspective. The case study shows a basic social distinction between developers and users (performance and audience role), organized in a pronounced centre-periphery relationship. Their cooperation is realized in form of a strongly factual structured system differentiation. Against this background an abstractive purpose-driven setting or programming of free/open software development can be reconstructed as an emergent principle of order and can be adducted for a functional understanding of system relation characteristics. These results provide important insights into the organizational strategies of joint production of knowledge on the Internet

Hepatitis B virus infection and the immune response: The big questions

Clinical events and the host immune response during hepatitis B virus (HBV) infection are intricately linked. Despite decades of research, important questions concerning the immunopathogenesis of chronic HBV infection remain unanswered. For example, it is unclear which immune parameters facilitate persistence, and if HBV can be completely cleared from the human liver. Recent technological breakthroughs now allow researchers to address these seemingly basic, but essential questions surrounding HBV immunity. It will be important to better define the molecular underpinnings of immune cell function and dysfunction during chronic disease and in controlled infection, with particular focus on the liver, as little information is available on the intrahepatic compartment. In the near future, it may be possible to solve some of the controversy surrounding the immune responses to HBV, and establish the features of both the innate and adaptive arms of the immune system required to achieve sustained control of HBV infection

A Comparative Transcriptome Analysis of Human and Porcine Choroid Plexus Cells in Response to Streptococcus suis Serotype 2 Infection Points to a Role of Hypoxia

Streptococcus suis (S. suis) is an important opportunistic pathogen, which can cause septicemia and meningitis in pigs and humans. Previous in vivo observations in S. suisinfected pigs revealed lesions at the choroid plexus (CP). In vitro experiments with primary porcine CP epithelial cells (PCPEC) and human CP epithelial papilloma (HIBCPP) cells demonstrated that S. suis can invade and traverse the CP epithelium, and that the CP contributes to the inflammatory response via cytokine expression. Here, next generation sequencing (RNA-seq) was used to compare global transcriptome profiles of PCPEC and HIBCPP cells challenged with S. suis serotype (ST) 2 infected in vitro, and of pigs infected in vivo. Identified differentially expressed genes (DEGs) were, amongst others, involved in inflammatory responses and hypoxia. The RNA-seq data were validated via quantitative PCR of selected DEGs. Employing Gene Set Enrichment Analysis (GSEA), 18, 28, and 21 enriched hallmark gene sets (GSs) were identified for infected HIBCPP cells, PCPEC, and in the CP of pigs suffering from S. suis ST2 meningitis, respectively, of which eight GSs overlapped between the three different sample sets. The majority of these GSs are involved in cellular signaling and pathways, immune response, and development, including inflammatory response and hypoxia. In contrast, suppressed GSs observed during in vitro and in vivo S. suis ST2 infections included those, which were involved in cellular proliferation and metabolic processes. This study suggests that similar cellular processes occur in infected human and porcine CP epithelial cells, especially in terms of inflammatory response

Chronic HCV Infection Affects the NK Cell Phenotype in the Blood More than in the Liver

Although epidemiological and functional studies have implicated NK cells in protection and early clearance of HCV, the mechanism by which they may contribute to viral control is poorly understood, particularly at the site of infection, the liver. We hypothesized that a unique immunophenotypic/functional NK cell signature exists in the liver that may provide insights into the contribution of NK cells to viral control. Intrahepatic and blood NK cells were profiled from chronically infected HCV-positive and HCV-negative individuals. Baseline expression of activating and inhibitory receptors was assessed, as well as functional responses following stimulation through classic NK cell pathways. Independent of HCV infection, the liver was enriched for the immunoregulatory CD56bright NK cell population, which produced less IFNγ and CD107a but comparable levels of MIP1β, and was immunophenotypically distinct from their blood counterparts. This profile was mostly unaltered in chronic HCV infection, though different expression levels of NKp46 and NKG2D were associated with different grades of fibrosis. In contrast to the liver, chronic HCV infection associated with an enrichment of CD161lowperforinhigh NK cells in the blood correlated with increased AST and 2B4 expression. However, the association of relatively discrete changes in the NK cell phenotype in the liver with the fibrosis stage nevertheless suggests an important role for the NK response. Overall these data suggest that tissue localization has a more pervasive effect on NK cells than the presence of chronic viral infection, during which these cells might be mostly attuned to limiting immunopathology. It will be important to characterize NK cells during early HCV infection, when they should have a critical role in limiting infection

A recombinant herpesviral vector containing a near-full-length SIVmac239 genome produces SIV particles and elicits immune responses to all nine SIV gene products

The properties of the human immunodeficiency virus (HIV) pose serious difficulties for the development of an effective prophylactic vaccine. Here we describe the construction and characterization of recombinant (r), replication-competent forms of rhesus monkey rhadinovirus (RRV), a gamma-2 herpesvirus, containing a near-full-length (nfl) genome of the simian immunodeficiency virus (SIV). A 306-nucleotide deletion in the pol gene rendered this nfl genome replication-incompetent as a consequence of deletion of the active site of the essential reverse transcriptase enzyme. Three variations were constructed to drive expression of the SIV proteins: one with SIV\u27s own promoter region, one with a cytomegalovirus (cmv) immediate-early promoter/enhancer region, and one with an RRV dual promoter (p26 plus PAN). Following infection of rhesus fibroblasts in culture with these rRRV vectors, synthesis of the early protein Nef and the late structural proteins Gag and Env could be demonstrated. Expression levels of the SIV proteins were highest with the rRRV-SIVcmv-nfl construct. Electron microscopic examination of rhesus fibroblasts infected with rRRV-SIVcmv-nfl revealed numerous budding and mature SIV particles and these infected cells released impressive levels of p27 Gag protein ( \u3e 150 ng/ml) into the cell-free supernatant. The released SIV particles were shown to be incompetent for replication. Monkeys inoculated with rRRV-SIVcmv-nfl became persistently infected, made readily-detectable antibodies against SIV, and developed T-cell responses against all nine SIV gene products. Thus, rRRV expressing a near-full-length SIV genome mimics live-attenuated strains of SIV in several important respects: the infection is persistent; \u3e 95% of the SIV proteome is naturally expressed; SIV particles are formed; and CD8+ T-cell responses are maintained indefinitely in an effector-differentiated state. Although the magnitude of anti-SIV immune responses in monkeys infected with rRRV-SIVcmv-nfl falls short of what is seen with live-attenuated SIV infection, further experimentation seems warranted