Numerical modeling of microplastic interaction with fine sediment under estuarine conditions

Microplastic (MP) pollution is an important challenge for human life which has consequently affected the natural system of other organisms. Mismanagement and also careless handling of plastics in daily life has led to an accelerating contamination of air, water and soil compartments with MP. Under estuarine conditions, interactions with suspended particulate matter (SPM) like fine sediment in the water column play an important role on the fate of MP. Further studies to better understand the corresponding transport and accumulation mechanisms are required. This paper aims at providing a new modeling approach improving the MP settling velocity formulation based on higher suspended fine sediment concentrations, as i.e. existent in estuarine turbidity zones (ETZ). The capability of the suggested approach is examined through the modeling of released MP transport in water and their interactions with fine sediment (cohesive sediment/fluid mud). The model results suggest higher concentrations of MP in ETZ, both in the water column as well as the bed sediment, which is also supported by measurements. The key process in the modeling approach is the integration of small MP particles into estuarine fine sediment aggregates. This is realized by means of a threshold sediment concentration, above which the effective MP settling velocity increasingly approaches that of the sediment aggregates. The model results are in good agreement with measured MP mass concentrations. Moreover, the model results also show that lighter small MP particles can easier escape the ETZ towards the open sea

High-affinity RNA binding by a hyperthermophilic single-stranded DNA-binding protein

Single-stranded DNA-binding proteins (SSBs), including replication protein A (RPA) in eukaryotes, play a central role in DNA replication, recombination, and repair. SSBs utilise an oligonucleotide/oligosaccharide-binding (OB) fold domain to bind DNA, and typically oligomerise in solution to bring multiple OB fold domains together in the functional SSB. SSBs from hyperthermophilic crenarchaea, such as Sulfolobus solfataricus, have an unusual structure with a single OB fold coupled to a flexible C-terminal tail. The OB fold resembles those in RPA, whilst the tail is reminiscent of bacterial SSBs and mediates interaction with other proteins. One paradigm in the field is that SSBs bind specifically to ssDNA and much less strongly to RNA, ensuring that their functions are restricted to DNA metabolism. Here, we use a combination of biochemical and biophysical approaches to demonstrate that the binding properties of S. solfataricus SSB are essentially identical for ssDNA and ssRNA. These features may represent an adaptation to a hyperthermophilic lifestyle, where DNA and RNA damage is a more frequent event.Publisher PDFPeer reviewe

Context-Awareness in MobiLife

approaching Context-Awareness from the perspective of mobile applications and their enabling components. It envisions a highly distributed and loosely coupled solution in order to exchange context information on different semantic context levels between applications, enabling components and raw context sources. Semantic meaning of the context information exchanged is added via distributed ontology’s attached to it. The definition of the mechanism and interfaces is described by the MobiLife Context Management Framework. Actual context data used within MobiLife applications is provided and defined by a number of specific context providers. New context providers can be easily introduced based on the generic definition of them. The paper aims to provide the overview to the MobiLife context-awareness approach and describes its usage by the means of two MobiLife applications

Multimodal Adaptation And Enriched Interaction Of Multimedia Content For Mobile Users

This paper introduces an architecture, together with an implemented scenario, capable of dynamically adapt the way mobile users consume and interact with multimedia content. The architecture is based on a representative scenario identified by the European project SPICE, in which multimedia content is distributed to a user independently of his/her contextual situation. The implemented scenario includes the following scenes: content selection using a personal mobile phone, content distribution to the most suitable device according to the user's context, and presentation continuity when the user moves to another location. This paper reports on the defined architecture and the current status of its implementation. It shows the initial results in the form of screenshots

Managing Personal Communication Environments in Next Generation Service Platforms

The current access to mobile services a user has, is defined by the user's mobile terminal as the single entry point to an operators network. This comes along with a set of limitations. Although performance and multimedia capabilities of mobile devices are constantly increasing, user-service interaction is still limited due to physical constraints imposed by the form factor. Another drawback is the varying ability of devices to download and execute new services. At the same time it is not possible to synchronise, exchange or share the user's data and media content among different devices. In order to overcome these limitations this paper presents the concept of the Distributed Communication Sphere and the according architectural framework that allows its management. This framework defines functional components to enable multi-device delivery of communication and media service sessions, user input interpretation, terminal management and resource discovery. It also provides flexible service delivery through the dynamic desktop component and relies on intelligent service enablers of the underlying service platform architecture, such as context-awareness, service provisioning and personal profile enablers. The work has been performed as part of the EU IST-SPICE (027617) project targeting intelligent extensions for next generation service platforms

Delivering Interactive Multimedia Services in Dynamic Pervasive Computing Environments

This paper introduces a distributed system for next generation multimedia support in dynamically changing pervasive computing environments. The overall goal is to enhance the experience of mobile users by intelligently adapting the way a service is presented, in particular by adapting the way the user receives multimedia content from the service and how he interacts with the service. The system tailors this presentation to the user's context, for instance based on his current activity (e.g., driving or walking) or the characteristics of the devices that surround him (e.g., devices for multimedia rendering and user interaction devices). The system integrates with the (IMS-based) service platforms of "beyond 3G" telecom operators and allows multimedia content to be rendered on multiple devices at the same time. It can also dynamically and seamlessly adapt the way a service is presented while it is being used (e.g., from gesture-based input to voice commands). These changes are triggered by changes in the user's context (e.g., when the user gets into his car). This paper discusses the system's requirements, presents an architecture proposal and describes its current implementation