QoS-Aware Resource Allocation for Mobile IoT Pub/Sub Systems

International audienceIoT applications are usually characterized by large-scale demand and the widespread use of mobile devices. Similarly, performing interaction among application and system components in a decoupled and elastic way, and enforcing Quality of Service (QoS) usually also become issues. Hence, paradigms such as pub/sub on top of cloud resources represent a suitable strategy for application development. However, management of QoS-aware resource allocation for pub/sub systems remains challenging, especially when system peers connect in an intermittent way. In this paper, we propose a new approach for resource allocation focusing on end-to-end performance in face of peers' disconnections. We evaluate and demonstrate the benefits of our approach using simulations. QoS enforcement was achieved in almost all scenarios, and we have shown that our approach can help reasoning about efficient resource allocation

Cross-layer QoS-Aware Resource Allocation for IoT-Enabled Service Choreographies

International audienceResource allocation for distributed systems is a well-known approach to deal with quality of service requirements. However, existing approaches do not consider the effects of resource allocation at the different levels of a system, especially when considering the end-to-end behavior of distributed compositions such as service choreographies. Based on our previous research on the optimized and QoS-aware resource allocation for service choreographies and publish-subscribe brokers, we outline a novel approach that integrates the treatment of resource allocation at both levels in orderto yield a more precise control over end-to-end QoS. The paper presents an early architecture and discusses some of the main challenges towards realizing the approach

Phosphorus removal from eutrophic waters with an aluminium hybrid nanocomposite

An excess of phosphorus (P) is the most common cause of eutrophication of freshwater bodies. Thus, it is imperative to reduce the concentration of P to prevent harmful algal blooms. Moreover, recovery of P has been gaining importance because its natural source will be exhausted in the near future. Therefore, the present work investigated the removal and recovery of phosphate from water using a newly developed hybrid nanocomposite containing aluminium nanoparticles (HPN). The HPN-Pr removes 0.80 ± 0.01 mg P/g in a pH interval between 2.0 and 6.5. The adsorption mechanism was described by a Freundlich adsorption model. The material presented good selectivity for phosphate and can be regenerated using an HCl dilute solution. The factors that contribute most to the attractiveness of HPN-Pr as a phosphate sorbent are its moderate removal capacity, feasible production at industrial scale, reuse after regeneration and recovery of phosphate.The authors acknowledge the Foundation for Science and Technology (FCT) Project SFRH/BD/39085/2007 for the financial support

MicroRNA biogenesis and their functions in regulating stem cell potency and differentiation

Stem cells are unspecialized/undifferentiated cells that exist in embryos and adult tissues or can be converted from somatic differentiated cells. Use of stem cells for tissue regeneration and tissue engineering has been a cornerstone of the regenerative medicine. Stem cells are also believed to exist in cancer tissues, namely cancer stem cells (CSCs). Growing evidence suggests that CSCs are the culprit of cancer dormancy, progression and recurrence, and thus have recently received great attention. MicroRNAs (miRNAs) are a group of short, non-coding RNAs that regulate expression of a wide range of genes at a post-transcriptional manner. They are emerging as key regulators of stem cell behaviors. This mini review summarizes the basic biogenesis and mode of actions of miRNAs, recent progress and discoveries of miRNAs in cellular reprogramming, stem cell differentiation and cellular communication, as well as miRNAs in CSCs. Some potential of miRNAs in future biomedical applications and research pertaining to stem cells are briefly discussed

A Middleware-based Approach for QoS-aware Deployment of Service Choreography in the Cloud

International audienceNon-functional requirements specification for an application and definition of required resources for its deployment are activities commonly performed at ad hoc, which can cause quality of service degradation due to inefficient use of re-sources. This problem is even greater with applications formed by the composition of multiple services. Cloud com-puting emerges as an alternative to provision of the needed resources, which is usually done using local infrastructure in conjunction with external providers. However, efficient resource management mechanisms and policies for offering quality services in these environments are necessary. This work is a PhD proposal, where is presented a middleware-based approach for cloud resources management and their provisioning according with non-funcional requirements and with greater usability by the deployer. Use of models at run-time and choreography of services for higher abstraction, adaptability and decentralization of the running system is proposed. Using this approach applications running in cloud environments may work based on their immediate needs

A Model-Based Approach to Pragmatic Service Choreography Deployment

International audienceThe development of applications using service choreographies is becoming one of the de facto standards for the Future Internet. However QoS-aware management of service compositions is usually performed without considering service sharing. This simplifying assumption makes choreography deployment less feasible in real scenarios, in which a single service is typically shared in many scenarios. In this paper we discuss the problem of managing multiple choreographies in multi-cloud environments and we advocate that sharing-aware deployment is a more effective and resource-efficient approach. We propose a model for the combined deployment of multiple choreographies on top of a shared set of services, and we further investigate the problem through experiments