11 research outputs found
Workshop:Perspectives on Safeguarding Indigenous Knowledge and Intangible Cultural Heritage
This proposed workshop aims to explore and share viewpoints on contentious matters concerning using ICT in the safeguarding of Indigenous Knowledge (IK) and Intangible Cultural Heritage (ICH). As organizers, we have formed long-lasting partnerships with indigenous communities and are frequently situated in these dialogical situations where topics such as ICT, cultural heritage and indigenous knowledge are debated. With this workshop, we intend to give the opportunity to discuss contentious issues of research impact among members of three groups: indigenous people that are contributing to, and affected by, research on IK; invited community–based co-designers and local researchers; and the organizers. Participants will identify and discuss crucial topics on the impact and ethics of IK research. We intend to collect viewpoints and arguments on how sensitive research in indigenous communities is to be carried out in order to meet the approval of actors from all three groups. We conclude by drafting a plan to implement suggested actions
Rural communities crowdsource technology development: a Namibian expedition.
In this paper, we describe our newest project endeavor in which we conceptualize crowdsourcing technology development for and with rural communities in Namibia. The project is based on design work which was carried out over a longer period of time with a single rural pilot community in Namibia and its transferability of technology and concepts into other rural communities. In an attempt to overcome expensive technology adaptations we explore the possibility of having rural communities' crowdsource their defined and specified technology needs. We describe the concept and our current implementation with a first user evaluation in two rural communities. We also discuss the next phase of the project
A Digital Indigenous Knowledge Preservation Framework: The 7C Model-Repositioning IK Holders in the Digitization of IK
Indigenous Knowledge (IK) preservation and management has been taken up as a serious endeavor by various governments who have realized the value of IK as well as the opportunities given by emerging technologies. Considering the various phases and activities of indigenous knowledge management which need to be supported through adequate designs and technologies, we propose an integrative framework: the 7C model. The aim is to guide design and implementation efforts as well as to identify and rectify any possible gaps in current implementation plans. The model comprises seven major phases within the indigenous knowledge digitization process, namely, codesign, conceptualization, collection, correction, curation, circulation, and creation of knowledge. We exemplify the application of the model with technologies currently developed under an indigenous knowledge holder’s toolkit promoting the agency of digitalizing indigenous knowledge across the phases
Namibian Indigenous Communities Reflecting on Their Own Digital Representations.
Indigenous communities' narratives have all too often been created, documented, curated and digitalized by aliens. This digital othering has created widely disseminated images and perceptions of indigenous communities which are neither authentic, nor in line with what the communities consider a valid or worthwhile representation of themselves or their cultural heritage. This has led to misconstrued and stereotypical perspectives by outsiders about indigenous communities. Technological interventions with indigenous communities to promote their sovereignty, while sometimes challenging, have opened critical debates around communities' self-determination of digital representations of their own cultural identities and heritage. We have entered into a dialogue with two Namibian indigenous communities, who have been our design partners on technology projects aimed at safeguarding their own cultural heritage on their own terms. We are reporting from our long-term ovaHimba collaborator who has engaged in a reflection about the preservation of his traditions triggered by our joint digitalization efforts. Moreover, in response to the widespread stereotyping of members of San communities in contemporary Namibia, that directly influences their cultural identity; we have co-constructed a video conversation between Namibians and a rural San community. In this way, the remote community could consider outsiders' perceptions, reflect upon and actively re-construct their digital self-representation. We discuss community reflections, self-representation and digital empowerment in the context of digitalization efforts
Environmental Salinity Determines the Specificity and Need for Tat-Dependent Secretion of the YwbN Protein in Bacillus subtilis
Twin-arginine protein translocation (Tat) pathways are required for transport of folded proteins across bacterial, archaeal and chloroplast membranes. Recent studies indicate that Tat has evolved into a mainstream pathway for protein secretion in certain halophilic archaea, which thrive in highly saline environments. Here, we investigated the effects of environmental salinity on Tat-dependent protein secretion by the Gram-positive soil bacterium Bacillus subtilis, which encounters widely differing salt concentrations in its natural habitats. The results show that environmental salinity determines the specificity and need for Tat-dependent secretion of the Dyp-type peroxidase YwbN in B. subtilis. Under high salinity growth conditions, at least three Tat translocase subunits, namely TatAd, TatAy and TatCy, are involved in the secretion of YwbN. Yet, a significant level of Tat-independent YwbN secretion is also observed under these conditions. When B. subtilis is grown in medium with 1% NaCl or without NaCl, the secretion of YwbN depends strictly on the previously described “minimal Tat translocase” consisting of the TatAy and TatCy subunits. Notably, in medium without NaCl, both tatAyCy and ywbN mutants display significantly reduced exponential growth rates and severe cell lysis. This is due to a critical role of secreted YwbN in the acquisition of iron under these conditions. Taken together, our findings show that environmental conditions, such as salinity, can determine the specificity and need for the secretion of a bacterial Tat substrate
Transport of Folded Proteins by the Tat System
The twin-arginine protein translocation (Tat) system has been characterized in bacteria, archaea and the chloroplast thylakoidal membrane. This system is distinct from other protein transport systems with respect to two key features. Firstly, it accepts cargo proteins with an N-terminal signal peptide that carries the canonical twin-arginine motif, which is essential for transport. Second, the Tat system only accepts and translocates fully folded cargo proteins across the respective membrane. Here, we review the core essential features of folded protein transport via the bacterial Tat system, using the three-component TatABC system of Escherichia coli and the two-component TatAC systems of Bacillus subtilis as the main examples. In particular, we address features of twin-arginine signal peptides, the essential Tat components and how they assemble into different complexes, mechanistic features and energetics of Tat-dependent protein translocation, cytoplasmic chaperoning of Tat cargo proteins, and the remarkable proofreading capabilities of the Tat system. In doing so, we present the current state of our understanding of Tat-dependent protein translocation across biological membranes, which may serve as a lead for future investigations
Sildenafil Citrate Increases Fetal Weight in a Mouse Model of Fetal Growth Restriction with a Normal Vascular Phenotype
Fetal growth restriction (FGR) is defined as the inability of a fetus to achieve its genetic growth potential and is associated with a significantly increased risk of morbidity and mortality. Clinically, FGR is diagnosed as a fetus falling below the 5(th) centile of customised growth charts. Sildenafil citrate (SC, Viagra™), a potent and selective phosphodiesterase-5 inhibitor, corrects ex vivo placental vascular dysfunction in FGR, demonstrating potential as a therapy for this condition. However, many FGR cases present without an abnormal vascular phenotype, as assessed by Doppler measures of uterine/umbilical artery blood flow velocity. Thus, we hypothesized that SC would not increase fetal growth in a mouse model of FGR, the placental-specific Igf2 knockout mouse, which has altered placental exchange capacity but normal placental blood flow. Fetal weights were increased (by 8%) in P0 mice following maternal SC treatment (0.4 mg/ml) via drinking water. There was also a trend towards increased placental weight in treated P0 mice (P = 0.056). Additionally, 75% of the P0 fetal weights were below the 5(th) centile, the criterion used to define human FGR, of the non-treated WT fetal weights; this was reduced to 51% when dams were treated with SC. Umbilical artery and vein blood flow velocity measures confirmed the lack of an abnormal vascular phenotype in the P0 mouse; and were unaffected by SC treatment. (14)C-methylaminoisobutyric acid transfer (measured to assess effects on placental nutrient transporter activity) per g placenta was unaffected by SC, versus untreated, though total transfer was increased, commensurate with the trend towards larger placentas in this group. These data suggest that SC may improve fetal growth even in the absence of an abnormal placental blood flow, potentially affording use in multiple sub-populations of individuals presenting with FGR
Rab6a/a' are important Golgi regulators of pro-inflammatory TNF secretion in macrophages
Lipopolysaccharide (LPS)-activated macrophages secrete pro-inflammatory cytokines, including tumor necrosis factor (TNF) to elicit innate immune responses. Secretion of these cytokines is also a major contributing factor in chronic inflammatory disease. In previous studies we have begun to elucidate the pathways and molecules that mediate the intracellular trafficking and secretion of TNF. Rab6a and Rab6a' (collectively Rab6) are trans-Golgi-localized GTPases known for roles in maintaining Golgi structure and Golgi-associated trafficking. We found that induction of TNF secretion by LPS promoted the selective increase of Rab6 expression. Depletion of Rab6 (via siRNA and shRNA) resulted in reorganization of the Golgi ribbon into more compact structures that at the resolution of electron microcopy consisted of elongated Golgi stacks that likely arose from fusion of smaller Golgi elements. Concomitantly, the delivery of TNF to the cell surface and subsequent release into the media was reduced. Dominant negative mutants of Rab6 had similar effects in disrupting TNF secretion. In live cells, Rab6-GFP were localized on trans-Golgi network (TGN)-derived tubular carriers demarked by the golgin p230. Rab6 depletion and inactive mutants altered carrier egress and partially reduced p230 membrane association. Our results show that Rab6 acts on TNF trafficking at the level of TGN exit in tubular carriers and our findings suggest Rab6 may stabilize p230 on the tubules to facilitate TNF transport. Both Rab6 isoforms are needed in macrophages for Golgi stack organization and for the efficient post-Golgi transport of TNF. This work provides new insights into Rab6 function and into the role of the Golgi complex in cytokine secretion in inflammatory macrophages