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The promise of the Internet of Things (IoT) and the many visions of unprecedented and transforming IoT applications are challenged by the realities of a highly fragmented ecosystem of devices, standards and industries. Systems research in IoT is shifting priorities to explore explicit "thing architectures" that promote and enable the friction-free interactions of things despite such fragmentations. In this paper, we focus on overcoming lightweight communication protocol fragmentation. We introduce the Atlas IoT communication framework which enables interactions among things that speak similar or different communication protocols. The framework tools up Atlas things with protocol translator "attachments" that could be either hosted on board the Atlas thing platform, or in the cloud. The translator enables the seamless communication between heterogeneous things through a set of well-defined interfaces. The proposed framework supports seamless communication among the widely adopted Constrained Application Protocol (CoAP), Representational State Transfer (REST) over Hypertext Transfer protocol HTTP, and the Message Queue Telemetry Transport protocol (MQTT). Our framework is carefully designed to facilitate interoperability among heterogeneously communicating things without taxing the performance of things that are homogenously communicating. The framework itself utilizes the topic concept and uses a meta-topic hierarchy to map out and guide the translations. We present the details of the Atlas IoT communication framework and give a detailed benchmarking study to measure the energy consumption and code footprint characteristics of the different aspects of the framework on real hardware platforms. In addition to basic characterizations, we compare our framework to the Eclipse Ponte framework and show how our framework is advantageous in energy consumption and how it is unique in that it does not tangibly penalize the homogeneous communication case.

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Stevia leaves contain various components, such as flavonoids, labdanes, chlorophylls, sterols, triterpenoids, mono-disaccharides, organic acids and inorganic salts. Stevia is known to accumulate diterpenoid steviol glycosides, which are approximately 300 times sweeter than regular sugar. Stevioside and rebaudioside A are the main diterpenic glycosides in stevia. Steviol glycosides are the secondary metabolites responsible for the sweetness of stevia. The main objectives of the present study were to determine the concentrations of diterpenic glycosides (stevioside and rebaudioside A) in three stevia varieties ( Stevia rebaudiana) via the HPLC-UV technique and to amplify the UGT76G1 gene by PCR using gene-specific primers. The expression levels of the UGT76G1 gene were determined in the three stevia varieties. The PCR products were sequenced and analyzed, and the nucleotide sequences of the UGT76G1 gene were submitted to GenBank and assigned to the following three varieties: Egy1 (MH087463), China1 (MH087464) and Sponti (MH087465). Cluster analysis was used to separate the three varieties into two major clusters based on their phylogenetic relationship. In addition, chemical analysis was carried out to evaluate stevioside and rebaudioside A. The present study concluded that Egy1 and Sponti are closely related varieties as they fall in the same cluster, while China1 forms a separate cluster. Bioprospecting studies could be useful for selection of superior ecotypes of Stevia rebaudiana .

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