Developing IoT applications in the Fog:a distributed dataflow approach

In this paper we examine the development of IoT applications from the perspective of the Fog Computing paradigm, where computing infrastructure at the network edge in devices and gateways is leverage for efficiency and timeliness. Due to the intrinsic nature of the IoT: heterogeneous devices/resources, a tightly coupled perception-action cycle and widely distributed devices and processing, application development in the Fog can be challenging. To address these challenges, we propose a Distributed Dataflow (DDF) programming model for the IoT that utilises computing infrastructures across the Fog and the Cloud. We evaluate our proposal by implementing a DDF framework based on Node-RED (Distributed Node-RED or D-NR), a visual programming tool that uses a flow-based model for building IoT applications. Via demonstrations, we show that our approach eases the development process and can be used to build a variety of IoT applications that work efficiently in the Fog

Smart cities:engaging users and developers to foster innovation ecosystems

Increasingly, city planners and government officials understand that cities are engines of innovation and wealth creation. Equally, there is a growing understanding that the application of technology in support of Smart Cities helps grow the urban economy and deliver better services to citizens. However, often Smart City projects are top- down projects focused on improving city infrastructure using technology. We argue, and our experience over the last decade has shown, that often, citizen driven, or grass-roots based Smart City projects deliver better value and sustainable success. In this paper we report on our work to engage citizens and the technology community in smart city projects and highlight some lessons learnt from our experiences. We show how a modest investment in a Smart City Data Hub (using our IoT platform – WoTKit) plus development tools based on Node-RED helps bootstrap a Smart City innovation cluster

Expression of flagellin FLjB derived from Salmonella enterica serovar typhimurium in Escherichia coli BL21

Flagellin FljB composes flagellar antigen (H:1,2) of S. Typhimurium. This kind of antigen increases immunogenicity of any conjugated antigen upon administration. Thus, it is supposed to have an enormous potentiality for vaccine development against bacterial infections and cancer diseases. fljB gene (1515 nucleotides) coding for mature FljB was amplified by PCR from genomic DNA of S. Typhimurium and inserted into pET32a(+) for expression in E. coli BL21. The protein FljB was well expressed under the fusion form with Trx, S-tag at N terminal and hexa-histidine at C terminal, thus the recombinant protein was abbreviated to TrxFljB. Study on the impact of temperature on the gene expression showed that TrxFljB was synthesized at lower level at 37oC comparing to the levels at 22oC and 25oC. 13% of the protein synthesized at 37oC was inclusion body. Lower temperatures used during induction phase increased the solubility of the recombinant protein. About 97% of TrxFljB synthesized at 25oC was soluble. IPTG concentration had a strong effect on the growth of freshly transformed cells but did not affect on the growth of stored and re-cultivated cells. The increase of IPTG concentration resulted in the decrease of the growth of freshly transformed cells and the TrxFljB productivity. However, 0.05 mM IPTG concentration was found to gain the full TrxFljB expression. TrxFljB productivity declined during storage of cells at 4oC and re-cultivation. At optimal condition, volumetric productivity of TrxFljB was about 300 mg/ l broth.