A Cloud Platform-as-a-Service for Multimedia Conferencing Service Provisioning

Multimedia conferencing is the real-time exchange of multimedia content between multiple parties. It is the basis of a wide range of applications (e.g., multimedia multiplayer game). Cloud-based provisioning of the conferencing services on which these applications rely will bring benefits, such as easy service provisioning and elastic scalability. However, it remains a big challenge. This paper proposes a PaaS for conferencing service provisioning. The proposed PaaS is based on a business model from the state of the art. It relies on conferencing IaaSs that, instead of VMs, offer conferencing substrates (e.g., dial-in signaling, video mixer and audio mixer). The PaaS enables composition of new conferences from substrates on the fly. This has been prototyped in this paper and, in order to evaluate it, a conferencing IaaS is also implemented. Performance measurements are also made.Comment: 6 pages, 6 figures, IEEE ISCC 201

Gaschromatography/mass spectrometry analysis of degradation of ethylacetoacetate achieved in shake flask culture using a previously characterized yeast strain Tichosporon dermatis.

Public and regulatory interest regarding the presence of pharmaceutically active compounds in the environment its increasing adverse impact has increased in the recent years. Detection of a wide variety of pharmaceutical compounds in water environment has been a serious and growing concern in the last few decades. Understanding the biological degradation of pharmaceutical compounds is essential for accurately determining their ultimate environmental fate, conducting accurate risk assessments, and improving removal of such micro pollutants.  Present investigation was designed to accomplish biodegradation of ethylacetoacetate in shake flask culture using whole cells of previously isolated and identified yeast strain Trichosporon dermatis, from pharmaceutical effluents using enrichment culture technique. The strain was cultivated for two generations on an orbital shaker at 120 rpm at 28 ± 20C and the biomass was separated by centrifugation at 10,000 rpm for 20 mts. Normal saline washed cells were used in degradation carried out in Erlenmeyer flasks containing 500 ml of mineral medium containing ethylacetoacetate at standard conditions; wet cell weight= 20g/l; ethylacetoacetate concentration = 0.5% in mineral medium (w/v); time of biodegradation= 72 hrs; temperature= 28 ± 20C. Gas chromatography/mass spectrometry (GC-MS) analysis of microbially degraded product revealed that complete degradation of ethylacetoacetate in mineral medium was achieved in 72 hours using whole cells of Trichosporon dermatis yeast strain. Degradation of ethylacetoacetate by this yeast strain has not been reported before the present investigation. Keywords: ethyl acetoacetate, biodegradation, Gass chromatography/mass spectrometry and effluents

A Cloud-Based Architecture for Multimedia Conferencing Service Provisioning

Multimedia conferencing is the real-time exchange of multimedia content between multiple parties. It is the basis of several interactive multiuser applications, such as distance learning and multimedia multiplayer online games. The cloud-based provisioning of the conferencing services on which these applications rely on can have several benefits, including the easy provisioning of new applications, efficient use of resources, and elastic scalability. This paper proposes a holistic cloud-based architecture for conferencing service provisioning, which covers both the infrastructure and platform layers of the cloud. The proposed infrastructure layer offers conferencing substrates-as-a-service (e.g., dial-in signaling, video mixing, and audio mixing), instead of virtual machines or containers. The platform layer abstracts the details of the conferencing concepts and offers a high-level interface to simplify conference service provisioning for a wide range of service and application providers (experts versus non-experts). It also enables the on-the-fly scaling of the running conferences while guaranteeing the required quality of service, enables substrates composition to create new conferencing services, and eases the reuse of conferencing services in building new applications. The presented architecture is supported by a proof-of-concept prototype and performance measurements. The latter provides the analysis of resource allocation efficiency and response time, as well as the scalability of the system under suboptimal and over-provisioned conditions. It also provides recommendations for service providers regarding the best alternatives for provisioning their service