Refine
H-BRS Bibliography
- no (55) (remove)
Departments, institutes and facilities
Document Type
- Conference Object (36)
- Article (15)
- Contribution to a Periodical (2)
- Patent (1)
- Report (1)
Year of publication
- 2019 (55) (remove)
Keywords
- security (3)
- HTTP (2)
- knowledge learning (2)
- neural networks (2)
- usable privacy (2)
- virtual reality (2)
- visualization (2)
- ALPS (1)
- Aktionswaren (1)
- Alternde Gesellschaft (1)
„Es gibt keine Lücke“
(2019)
While universities are mandated to teach, research and do community outreach, studies reveal that typical university communities live in relative isolation where research is more basic than applied. This study focused on; 1) determining how WWE could be fostered through linkages between universities and external agencies (communities, public and private sectors); 2) establishing how universities’ resources could be optimized to promote research and capacity building for WWE. The dimensions of WWE studied were; 1) Technical & Business Models; 2) Capacity building; and 3) institutional frameworks. Baseline studies were conducted in which qualitative and quantitative data was collected through questionnaires, interviews, documents analysis. Experimentations were carried out whereby Laboratory tests on Bio-methane Potential (BMP) for different biomass types was conducted. A complete chain of briquettes production and consumption has been successfully piloted at St Kizito High School in Namugongo, near Kampala. The 20,000 kg of briquettes produced (from municipal bio-waste) by students monthly are used to cook in three schools whose total population is 2000 students. With an average net profit of $ 3000, the project makes business sense even in absence of social-benefit accounting. Based on start-up capital of $ 12,250, the payback period on investment is 14.7 months. Bio-char (from carbonized waste) and briquette-ash are used as organic fertilizers and biocide in vegetable gardens at the schools. New pathways for municipal waste management based on stakeholder engagement and entrepreneurship are demonstrated; departing from the conventional waste collection and disposal models. This circular enterprise which enhances Food, Agriculture, Biodiversity, Land-use and Energy (FABLE) nexus will scale-up to incorporate non-student communities (youths/women), private waste-collectors and entrepreneurs. The application of entrepreneurial models for engaging students in green enterprises integrates technological, social, economic and governance dimensions for promoting municipal sanitation, environment; energy and food security.
Plant sap-feeding insects are widespread, having evolved to occupy diverse environmental niches despite exclusive feeding on an impoverished diet lacking in essential amino acids and vitamins. Success depends exquisitely on their symbiotic relationships with microbial symbionts housed within specialized eukaryotic bacteriocyte cells. Each bacteriocyte is packed with symbionts that are individually surrounded by a host-derived symbiosomal membrane representing the absolute host-symbiont interface. The symbiosomal membrane must be a dynamic and selectively permeable structure to enable bidirectional and differential movement of essential nutrients, metabolites, and biosynthetic intermediates, vital for growth and survival of host and symbiont. However, despite this crucial role, the molecular basis of membrane transport across the symbiosomal membrane remains unresolved in all bacteriocyte-containing insects. A transport protein was immuno-localized to the symbiosomal membrane separating the pea aphid Acyrthosiphon pisum from its intracellular symbiont Buchnera aphidicola. The transporter, A. pisum nonessential amino acid transporter 1, or ApNEAAT1 (gene: ACYPI008971), was characterized functionally following heterologous expression in Xenopus oocytes, and mediates both inward and outward transport of small dipolar amino acids (serine, proline, cysteine, alanine, glycine). Electroneutral ApNEAAT1 transport is driven by amino acid concentration gradients and is not coupled to transmembrane ion gradients. Previous metabolite profiling of hemolymph and bacteriocyte, alongside metabolic pathway analysis in host and symbiont, enable prediction of a physiological role for ApNEAAT1 in bidirectional host-symbiont amino acid transfer, supplying both host and symbiont with indispensable nutrients and biosynthetic precursors to facilitate metabolic complementarity.
For protection from inhaled pathogens many strategies have evolved in the airways such as mucociliary clearance and cough. We have previously shown that protective respiratory reflexes to locally released bacterial bitter taste substances are most probably initiated by tracheal brush cells (BC). Our single-cell RNA-seq analysis of murine BC revealed high expression levels of cholinergic and bitter taste signaling transcripts (Tas2r108, Gnat3, Trpm5). We directly demonstrate the secretion of acetylcholine (ACh) from BC upon stimulation with the Tas2R agonist denatonium. Inhibition of the taste transduction cascade abolished the increase in [Ca2+](i) in BC and subsequent ACh-release. ACh-release is regulated in an autocrine manner. While the muscarinic ACh-receptors M3R and M1R are activating, M2R is inhibitory. Paracrine effects of ACh released in response to denatonium included increased [Ca2+](i) in ciliated cells. Stimulation by denatonium or with Pseudomonas quinolone signaling molecules led to an increase in mucociliary clearance in explanted tracheae that was Trpm5- and M3R-mediated. We show that ACh-release from BC via the bitter taste cascade leads to immediate paracrine protective responses that can be boosted in an autocrine manner. This mechanism represents the initial step for the activation of innate immune responses against pathogens in the airways.
Towards self-explaining social robots. Verbal explanation strategies for a needs-based architecture
(2019)
In order to establish long-term relationships with users, social companion robots and their behaviors need to be comprehensible. Purely reactive behavior such as answering questions or following commands can be readily interpreted by users. However, the robot's proactive behaviors, included in order to increase liveliness and improve the user experience, often raise a need for explanation. In this paper, we provide a concept to produce accessible “why-explanations” for the goal-directed behavior an autonomous, lively robot might produce. To this end we present an architecture that provides reasons for behaviors in terms of comprehensible needs and strategies of the robot, and we propose a model for generating different kinds of explanations.
Namibia’s hunting industry is increasingly threatened by animal rightists and opponent groups whose adversarial mindset is mostly based on emotion orientated information. The fatal consequences if closing hunting tourism in a country like Namibia are expounded in this study by critically investigating the input of well-regulated hunting tourism towards conservation in Namibia. Different factors have to be taken into consideration, regarding the country’s attributes that differ significantly from other countries and their methods to achieve successful conservation management strategies. By conducting an in-depth interview with Mr. Volker Grellmann and by obtaining secondary data from local authorities and organizations, the current research investigates how well-regulated hunting tourism in Namibia is an important part of biodiversity conservation. The results outline that hunting tourism is crucial for the value of wildlife and yields for wildlife to have a greater benefit than livestock and crop farming in Namibia. Likewise, the country takes care of their valuable natural recourse. As a result, natural habitats are induced, and subsequently a steeply growing number of wildlife was recorded over the last 50 years in Namibia. Among others hunting tourism favors the development of rural areas and yields incentives to fight poaching and the illegal trade of wild animal products.
The pyrin inflammasome has evolved as an innate immune sensor to detect bacterial toxin-induced Rho guanosine triphosphatase (Rho GTPase)-inactivation, a process that is similar to the "guard" mechanism in plants. Rho GTPases act as molecular switches to regulate a variety of signal transduction pathways including cytoskeletal organization. Pathogens can modulate Rho GTPase activity to suppress host immune responses such as phagocytosis. Pyrin is encoded by MEFV, the gene that is mutated in patients with familial Mediterranean fever (FMF). FMF is the prototypic autoinflammatory disease characterized by recurring short episodes of systemic inflammation and is a common disorder in many populations in the Mediterranean basin. Pyrin specifically senses modifications in the activity of the small GTPase RhoA, which binds to many effector proteins including the serine/threonine-protein kinases PKN1 and PKN2 and actin-binding proteins. RhoA activation leads to PKN-mediated phosphorylation-dependent pyrin inhibition. Conversely, pathogen virulence factors downregulate RhoA activity in a variety of ways, and these changes are detected by the pyrin inflammasome irrespective of the type of modifications. MEFV pathogenic variants favor the active state of pyrin and elicit proinflammatory cytokine release and pyroptosis. They can be inherited either as a dominant or recessive trait depending on the variant's location and effect on the protein function. Mutations in the C-terminal B30.2 domain are usually considered recessive, although heterozygotes may manifest a biochemical or even a clinical phenotype. These variants are hypomorphic in regard to their effect on intramolecular interactions, but ultimately accentuate pyrin activity. Heterozygous mutations in other domains of pyrin affect residues critical for inhibition or protein oligomerization, and lead to constitutively active inflammasome. In healthy carriers of FMF mutations who have the subclinical inflammatory phenotype, the increased activity of pyrin might have been protective against endemic infections over human history. This finding is supported by the observation of high carrier frequencies of FMF-mutations in multiple populations. The pyrin inflammasome also plays a role in mediating inflammation in other autoinflammatory diseases linked to dysregulation in the actin polymerization pathway. Therefore, the assembly of the pyrin inflammasome is initiated in response to fluctuations in cytoplasmic homeostasis and perturbations in cytoskeletal dynamics.
Small, Medium and Micro Enterprises (SMMEs) are widely recognised as playing a pivotal role in economic development and job creation. This is particularly so in Africa, where SMMEs are responsible for 80% of all formal jobs. While this is recognised by various African continental and national developments plans, the nefarious practice of late payment, by especially governments, not only stunt the growth of SMMEs, but often-time leads to business failure. This article investigates the impact of late payment, with a specific focus on South Africa and touches on international good practice that may be employed to address this phenomenon.
This article examines similarities and differences in the attitudes and social representations of destination managers towards implementing sustainable tourism between the mountain regions of the Alps and the Dinarides. Bearing in mind the transnational impacts (i.e., environmental, economic and social) of the tourism industry the research methodology adopted an international perspective by sending a questionnaire to tourism organizations in fourteen different countries in the Alps and the Dinarides. The research is interdisciplinary in nature, because it integrates knowledge from sustainability and management science with tourism geography and social psychology. The findings confirm that social representations of sustainable tourism differ significantly in the two mountain regions.
This study sought to examine the relationship between the components of SMEs social capital and firm performance. Using the social capital theory and the resource-based view as the theoretical foundations and census, 1,532 SMEs were selected in the Accra Metropolis for the study. Empirical results from 717 SMEs, utilising the hierarchical linear regression model, revealed that owner/manger’s network relationships are beneficial to the firm depending on when the relationships are closed or opened. Moreover, the study found that social capital has a significant impact on the sales and market performance of small and medium-sized enterprises. The results also brought to the fore the fact that most social networks of SME entrepreneurs are family, friends and relatives, which most times can only be used for expressive purposes and not for instrumental gain. The practical implications of the results are also discussed.
Innovation has been touted to be the central catalyst of entrepreneurship. This view has dominated research in start-ups as well as small and medium enterprises. Therefore, the relationship between innovation and firm performance has been a subject of interest to many researchers and policy makers. Through a longitudinal approach, this study investigated the influence of product innovation on the performance of Haco Tiger Brands, a medium sized fast-moving consumer goods (FMCG) company in Kenya’s East Africa market. The study looked at the product innovation activities within the company for a period of 7 years for a total of 35 products across the five major brand categories of the company. Using a secondary data capture form, data on sales revenues for both the company and innovated products for the past 7 years was obtained. Data on the innovated products launch time and type of innovation was also obtained. Using time series and linear regression analysis, the results indicate that the total company sales revenues less innovation grew at a slower rate of 50% as compared to growth when product innovation sales revenues were included in the total company sales revenues accounting for a faster sales growth rate of 76%. The influence of product innovation on performance was statistically significant (p<0.05) accounting for 92.19% variation in performance. These findings provide irrefutable empirical basis that product innovations have significant revenue growth rates, hence the need for managers of medium sized companies to invest in research and development to sustain product innovation and spur growth. The results sit well within theory and other empirical studies with additional contribution to methodology. Based on the study limitations, further areas for research have been suggested.
Pan-African University (PAU) is an initiative of the African Union Commission (AUC) that started in 2008 with the objective to promote higher education, science and technology on the African continent at a high academic level. The Pan-African University Institute of Water and Energy Sciences (including Climate Change) (PAUWES) is one of the five hubs of the Pan African University (PAU) and hosted at the University of Tlemcen in Algeria. PAUWES offers graduate students access to leading academic research and the latest theoretical and hands-on training in areas vital to the future of Africa’s development in water, energy and the challenge of climate change.
Contemporary software is inherently distributed. The principles guiding the design of such software have been mainly manifested by the service-oriented architecture (SOA) concept. In a SOA, applications are orchestrated by software services generally operated by distinct entities. Due to the latter fact, service security has been of importance in such systems ever since. A dominant protocol for implementing SOA-based systems is SOAP, which comes with a well-elaborated security framework. As an alternative to SOAP, the architectural style representational state transfer (REST) is gaining traction as a simple, lightweight and flexible guideline for designing distributed service systems that scale at large. This paper starts by introducing the basic constraints representing REST. Based on these foundations, the focus is afterwards drawn on the security needs of REST-based service systems. The limitations of transport-oriented protection means are emphasized and the demand for specific message-oriented safeguards is assessed. The paper then reviews the current activities in respect to REST-security and finds that the available schemes are mostly HTTP-centered and very heterogeneous. More importantly, all of the analyzed schemes contain vulnerabilities. The paper contributes a methodology on how to establish REST-security as a general security framework for protecting REST-based service systems of any kind by consistent and comprehensive protection means. First adoptions of the introduced approach are presented in relation to REST message authentication with instantiations for REST-ful HTTP (web/cloud services) and REST-ful constraint application protocol (CoAP) (internet of things (IoT) services).
We present a systematization of usable security principles, guidelines and patterns to facilitate the transfer of existing knowledge to researchers and practitioners. Based on a literature review, we extracted 23 principles, 11 guidelines and 47 patterns for usable security and identified their interconnection. The results indicate that current research tends to focus on only a subset of important principles. The fact that some principles are not yet addressed by any design patterns suggests that further work on refining these patterns is needed. We developed an online repository, which stores the harmonized principles, guidelines and patterns. The tool enables users to search for relevant guidance and explore it in an interactive and programmatic manner. We argue that both the insights presented in this article and the web-based repository will be highly valuable for students to get a good overview, practitioners to implement usable security and researchers to identify areas of future research.