Setting Rules for 2.7 Billion: a (First) Look into Facebook's Norm-Making System; Results of a Pilot Study

Sie regeln, was auf der Plattform Facebook gesagt werden darf und was gelöscht werden muss, und beeinflussen damit, wie 2,7 Milliarden Nutzer miteinander in Kontakt treten können: Facebooks Gemeinschaftsstandards sind ein Beispiel für den großen Einfluss, den Regeln privater Akteure auf die öffentliche Kommunikation haben. In einer Pilotstudie haben Forscher des Leibniz-Instituts für Medienforschung nun erforscht, wie Facebook seine Regeln entwickelt und welche Maßstäbe und Interessen in diesen Prozess einfließen. Matthias C. Kettemann, Forschungsprogrammleiter und Senior Researcher am HBI, hat eine Woche lang als Beobachter an sämtlichen Meetings des Product Policy Teams teilgenommen, das im Hauptquartier von Facebook in Kalifornien für die Entwicklung der Gemeinschaftsstandards verantwortlich ist. Darüber hinaus hat er in ausführlichen Interviews mit den verantwortlichen Personen untersucht, was die Entstehung neuer Regeln und deren Design motiviert und wie Facebook versucht, durch Konsultationen mit gesellschaftlichen Stakeholdern die Legitimität der privaten Normenordnung zu erhöhen. "Über das Entstehen von Gesetzen wissen wir viel, aber über die Entwicklung der selbst auferlegten Regeln, nach denen Facebook etwa Inhalte löscht, wussten wir bisher nichts", so Kettemann. "Das war lange eine Black Box", meint Prof. Dr. Wolfgang Schulz, Direktor des HBI, "in die wir nun Licht bringen konnten"

Probleme und Potenziale des NetzDG - ein Reader mit fünf HBI-Expertisen

Das NetzDG ist seit Januar 2018 vollständig in Kraft und zielt u. a. auf die Bekämpfung von Hassrede und anderer strafbarer Inhalte auf sozialen Plattformen einer gewissen Größe ab. Das Gesetz sieht Berichtspflichten sowie die Pflicht eines effektiven Beschwerdemanagements vor und ist sowohl in der Wissenschaft als auch in der Praxis auf einige Kritik gestoßen. Das Leibniz-Institut für Medienforschung | Hans-Bredow-Institut (HBI) hat die Gelegenheiten genutzt, für die Konzeptions- über die Implementierungs- bis hin zur Reformphase des NetzDG wissenschaftlichen Input zu geben. Mit Wolfgang Schulz und Matthias C. Kettemann waren zwei Institutsmitglieder als Sachverständige in verschiedenen Phasen der parlamentarischen Befassung mit dem Gesetz geladen. Das vorliegende Arbeitspapier versammelt fünf Beiträge aus den Federn von Wolfgang Schulz, Matthias C. Kettemann und Amélie Heldt, die in den Jahren 2018-2019 erschienen sind bzw. für Anhörungen erstellt wurden und das NetzDG aus unterschiedlichen Perspektiven thematisieren: Wolfgang Schulz’ Beitrag Regulating Intermediaries to Protect Privacy Online - the Case of the German NetzDG stellte die erste englischsprachige Analyse des Gesetzes dar und wurde weltweit stark gelesen. Anlässlich des Internet Governance Forum (Deutschland) 2018 in Berlin wurde Matthias C. Kettemann vom Center on Deliberative Democracy der Stanford University eingeladen, "Balanced Briefing Materials" zu erstellen, um die Diskussion über das NetzDG zu versachlichen. Amélie Pia Heldt untersucht in ihrem Beitrag aus dem Jahr 2019 die ersten Berichte von Intermediären nach dem NetzDG. Matthias C. Kettemann hat eine Stellungnahme als Sachverständiger für die öffentliche Anhörung zum Netzwerkdurchsetzungsgesetz auf Einladung des Ausschusses für Recht und Verbraucherschutz des Deutschen Bundestags vom Mai 2019 erarbeitet. Matthias C. Kettemann hat zudem eine Analyse für den Europarat verfasst, die einen Überblick über den Umgang mit illegalen Internet-Inhalten in Deutschland 2016-2019 bietet

Assessing agreement between preclinical magnetic resonance imaging and histology: An evaluation of their image qualities and quantitative results

One consequence of demographic change is the increasing demand for biocompatible materials for use in implants and prostheses. This is accompanied by a growing number of experimental animals because the interactions between new biomaterials and its host tissue have to be investigated. To evaluate novel materials and engineered tissues the use of nondestructive imaging modalities have been identified as a strategic priority. This provides the opportunity for studying interactions repeatedly with individual animals, along with the advantages of reduced biological variability and decreased number of laboratory animals. However, histological techniques are still the golden standard in preclinical biomaterial research. The present article demonstrates a detailed method comparison between histology and magnetic resonance imaging. This includes the presentation of their image qualities as well as the detailed statistical analysis for assessing agreement between quantitative measures. Exemplarily, the bony ingrowth of tissue engineered bone substitutes for treatment of a cleft-like maxillary bone defect has been evaluated. By using a graphical concordance analysis the mean difference between MRI results and histomorphometrical measures has been examined. The analysis revealed a slightly but significant bias in the case of the bone volume ðbiasHisto MRI: Bonevolume = 2: 40 %, p < 0: 005) and a clearly significant deviation for the remaining defect width ðbiasHisto MRI: Defectwidth = 6: 73 %, p 0: 005Þ: But the study although showed a considerable effect of the analyzed section position to the quantitative result. It could be proven, that the bias of the data sets was less originated due to the imaging modalities, but mainly on the evaluation of different slice positions. The article demonstrated that method comparisons not always need the use of an independent animal study, additionally

Definition of Core Bacterial Taxa in Different Root Compartments of Dactylis glomerata, Grown in Soil under Different Levels of Land Use Intensity

Plant-associated bacterial assemblages are critical for plant fitness. Thus, identifying a consistent plant-associated core microbiome is important for predicting community responses to environmental changes. Our target was to identify the core bacterial microbiome of orchard grass Dactylis glomerata L. and to assess the part that is most sensitive to land management. Dactylis glomerata L. samples were collected from grassland sites with contrasting land use intensities but comparable soil properties at three different timepoints. To assess the plant-associated bacterial community structure in the compartments rhizosphere, bulk soil and endosphere, a molecular barcoding approach based on high throughput 16S rRNA amplicon sequencing was used. A distinct composition of plant-associated core bacterial communities independent of land use intensity was identified. Pseudomonas, Rhizobium and Bradyrhizobium were ubiquitously found in the root bacterial core microbiome. In the rhizosphere, the majority of assigned genera were Rhodoplanes, Methylibium, Kaistobacter and Bradyrhizobium. Due to the frequent occurrence of plant-promoting abilities in the genera found in the plant-associated core bacterial communities, our study helps to identify “healthy” plant-associated bacterial core communities. The variable part of the plant-associated microbiome, represented by the fluctuation of taxa at the different sampling timepoints, was increased under low land use intensity. This higher compositional variation in samples from plots with low land use intensity indicates a more selective recruitment of bacteria with traits required at different timepoints of plant development compared to samples from plots with high land use intensity

App-based rehabilitation program after total knee arthroplasty: a randomized controlled trial

Introduction: New app-based programs for postoperative rehabilitation have been developed, but no long-term study has been published to date. Thus, a prospective randomized control trial with 2-year follow-up was performed to evaluate the effectiveness of app-based rehabilitation (GenuSport) compared to a control group after total knee arthroplasty (TKA). Methods: Between April and October 2016, 60 patients were enrolled in the study. Twenty-five patients were lost to follow-up, leaving 35 patients undergoing TKA for inclusion. In this group, twenty patients received app-based exercise program and 15 were randomized to the control group. The mean age was 64.37 +/- 9.32 years with a mean follow-up of 23.51 +/- 1.63 months. Patients in the app group underwent an app-based knee training starting on the day of surgery; whereas, patients in the control group underwent regular physiotherapy. Functional outcome scores using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS) and VAS of pain were analyzed. Results: In the short term, significant differences between the app group and control group in time of 10-m walk (19.66 +/- 7.80 vs. 27.08 +/- 15.46 s; p = 0.029), VAS pain at rest and activity (2.65 +/- 0.82 vs. 3.57 +/- 1.58, respectively 4.03 +/- 1.26 vs. 5.05 +/- 1.21; p < 0.05) were observed. In the long term, a variety of different tendencies was found, highest in KSS Function with 76.32 +/- 16.49 (app group) vs. 67.67 +/- 16.57 (control group) (p = 0.130). Additionally, patients in the app group required less painkillers (10.0% vs. 26.7%) and more likely to participate in sports (65.0% vs. 53.3%). Conclusions: An app-based knee trainer is a promising tool in improving functional outcomes such as KSS function score and VAS after TKA

Quantum spin ladders of non-Abelian anyons

Quantum ladder models, consisting of coupled chains, form intriguing systems bridging one and two dimensions and have been well studied in the context of quantum magnets and fermionic systems. Here we consider ladder systems made of more exotic quantum mechanical degrees of freedom, so-called non-Abelian anyons, which can be thought of as certain quantum deformations of ordinary SU(2) spins. Such non-Abelian anyons occur as quasiparticle excitations in topological quantum fluids, including p_x + i p_y superconductors, certain fractional quantum Hall states, and rotating Bose-Einstein condensates. Here we use a combination of exact diagonalization and conformal field theory to determine the phase diagrams of ladders with up to four chains. We discuss how phenomena familiar from ordinary SU(2) spin ladders are generalized in their anyonic counterparts, such as gapless and gapped phases, odd/even effects with the ladder width, and elementary `magnon' excitations. Other features are entirely due to the topological nature of the anyonic degrees of freedom.Comment: 12 pages, 17 figures, 3 tables, 2 references adde

A Versatile Macromer-Based Glycosaminoglycan (sHA3) Decorated Biomaterial for Pro-Osteogenic Scavenging of Wnt Antagonists

High serum levels of Wnt antagonists are known to be involved in delayed bone defect healing. Pharmaceutically active implant materials that can modulate the micromilieu of bone defects with regard to Wnt antagonists are therefore considered promising to support defect regeneration. In this study, we show the versatility of a macromer based biomaterial platform to systematically optimize covalent surface decoration with high-sulfated glycosaminoglycans (sHA3) for efficient scavenging of Wnt antagonist sclerostin. Film surfaces representing scaffold implants were cross-copolymerized from three-armed biodegradable macromers and glycidylmethacrylate and covalently decorated with various polyetheramine linkers. The impact of linker properties (size, branching) and density on sHA3 functionalization efficiency and scavenging capacities for sclerostin was tested. The copolymerized 2D system allowed for finding an optimal, cytocompatible formulation for sHA3 functionalization. On these optimized sHA3 decorated films, we showed efficient scavenging of Wnt antagonists DKK1 and sclerostin, whereas Wnt agonist Wnt3a remained in the medium of differentiating SaOS-2 and hMSC. Consequently, qualitative and quantitative analysis of hydroxyapatite staining as a measure for osteogenic differentiation revealed superior mineralization on sHA3 materials. In conclusion, we showed how our versatile material platform enables us to efficiently scavenge and inactivate Wnt antagonists from the osteogenic micromilieu. We consider this a promising approach to reduce the negative effects of Wnt antagonists in regeneration of bone defects via sHA3 decorated macromer based macroporous implants. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Lineage-specific T-cell responses to cancer mucosa antigen oppose systemic metastases without mucosal inflammatory disease.

Cancer mucosa antigens are emerging as a new category of self-antigens expressed normally in immunologically privileged mucosal compartments and universally by their derivative tumors. These antigens leverage the established immunologic partitioning of systemic and mucosal compartments, limiting tolerance opposing systemic antitumor efficacy. An unresolved issue surrounding self-antigens as immunotherapeutic targets is autoimmunity following systemic immunization. In the context of cancer mucosa antigens, immune effectors to self-antigens risk amplifying mucosal inflammatory disease promoting carcinogenesis. Here, we examined the relationship between immunotherapy for systemic colon cancer metastases targeting the intestinal cancer mucosa antigen guanylyl cyclase C (GCC) and its effect on inflammatory bowel disease and carcinogenesis in mice. Immunization with GCC-expressing viral vectors opposed nascent tumor growth in mouse models of pulmonary metastasis, reflecting systemic lineage-specific tolerance characterized by CD8(+), but not CD4(+), T-cell or antibody responses. Responses protecting against systemic metastases spared intestinal epithelium from autoimmunity, and systemic GCC immunity did not amplify chemically induced inflammatory bowel disease. Moreover, GCC immunization failed to promote intestinal carcinogenesis induced by germ-line mutations or chronic inflammation. The established role of CD8(+) T cells in antitumor efficacy, but CD4(+) T cells in autoimmunity, suggests that lineage-specific responses to GCC are particularly advantageous to protect against systemic metastases without mucosal inflammation. These observations support the utility of GCC-targeted immunotherapy in patients at risk for systemic metastases, including those with inflammatory bowel disease, hereditary colorectal cancer syndromes, and sporadic colorectal cancer

Human Coronavirus NL63 Open Reading Frame 3 encodes a virion-incorporated N-glycosylated membrane protein

Background: Human pathogenic coronavirus NL63 (hCoV-NL63) is a group 1 (alpha) coronavirus commonly associated with respiratory tract infections. In addition to known non-structural and structural proteins all coronaviruses have one or more accessory proteins whose functions are mostly unknown. Our study focuses on hCoV-NL63 open reading frame 3 (ORF 3) which is a highly conserved accessory protein among coronaviruses. Results: In-silico analysis of the 225 amino acid sequence of hCoV-NL63 ORF 3 predicted a triple membranespanning protein. Expression in infected CaCo-2 and LLC-MK2 cells was confirmed by immunofluorescence and Western blot analysis. The protein was detected within the endoplasmatic reticulum/Golgi intermediate compartment (ERGIC) where coronavirus assembly and budding takes place. Subcellular localization studies using recombinant ORF 3 protein transfected in Huh-7 cells revealed occurrence in ERGIC, Golgi- and lysosomal compartments. By fluorescence microscopy of differently tagged envelope (E), membrane (M) and nucleocapsid (N) proteins it was shown that ORF 3 protein colocalizes extensively with E and M within the ERGIC. Using N-terminally FLAG-tagged ORF 3 protein and an antiserum specific to the C-terminus we verified the proposed topology of an extracellular N-terminus and a cytosolic C-terminus. By in-vitro translation analysis and subsequent endoglycosidase H digestion we showed that ORF 3 protein is N-glycosylated at the N-terminus. Analysis of purified viral particles revealed that ORF 3 protein is incorporated into virions and is therefore an additional structural protein. Conclusions: This study is the first extensive expression analysis of a group 1 hCoV-ORF 3 protein. We give evidence that ORF 3 protein is a structural N-glycosylated and virion-incorporated protein.Web of Scienc