Software defined networking, characterized by a clear separation of the control and data planes, is being adopted as a novel paradigm for wired networking. With SDN, network operators can run their ...infrastructure more efficiently, supporting faster deployment of new services while enabling key features such as virtualization. In this article, we adopt an SDN-like approach applied to wireless mobile networks that will not only benefit from the same features as in the wired case, but will also leverage on the distinct features of mobile deployments to push improvements even further. We illustrate with a number of representative use cases the benefits of the adoption of the proposed architecture, which is detailed in terms of modules, interfaces, and high-level signaling. We also review the ongoing standardization efforts, and discuss the potential advantages and weaknesses, and the need for a coordinated approach.
Nitrogen (N) plays a key role in the plant life cycle. It is the main plant mineral nutrient needed for chlorophyll production and other plant cell components (proteins, nucleic acids, amino acids). ...Crop yield is affected by plant N status. Thus, the optimization of nitrogen fertilization has become the object of intense research due to its environmental and economic impact. This article focuses on reviewing current methods and techniques used to determine plant N status. Kjeldahl digestion and Dumas combustion have been used as reference methods for N determination in plants, but they are destructive and time consuming. By using spectroradiometers, reflectometers, imagery from satellite sensors and digital cameras, optical properties have been measured to estimate N in plants, such as crop canopy reflectance, leaf transmittance, chlorophyll and polyphenol fluorescence. High correlation has been found between optical parameters and plant N status, and those techniques are not destructive. However, some drawbacks include chlorophyll saturation, atmospheric and soil interference, and the high cost of instruments. Electrical properties of plant tissue have been used to estimate quality in fruits, and water content in plants, as well as nutrient deficiency, which suggests that they have potential for use in plant N determination.
The introduction of new services requiring large and dynamic bitrate connectivity can cause changes in the direction of the traffic in metro and even core network segments throughout the day. This ...leads to large overprovisioning in statically managed virtual network topologies (VNTs), which are designed to cope with the traffic forecast. To reduce expenses while ensuring the required grade of service, in this paper we propose a VNT reconfiguration approach based on data analytics for traffic prediction (VENTURE). It regularly reconfigures the VNT based on the predicted traffic, thus adapting the topology to both the current and the predicted traffic volume and direction. A machine learning algorithm based on an artificial neural network is used to provide robust and adaptive traffic models. The reconfiguration problem that takes as its input the traffic prediction is modeled mathematically, and a heuristic is proposed to solve it in practical times. To support VENTURE, we propose an architecture that allows collecting and storing data from monitoring at the routers and that is used to train predictive models for every origin-destination pair. Exhaustive simulation results of the algorithm, together with the experimental assessment of the proposed architecture, are finally presented.
Given the linkages between natural resources and social conflicts, evidence increasingly shows that successful natural resource management requires conflict mitigation and prevention. However, there ...may be a gap in practice between knowing what processes and tools need to be used to manage conservation conflicts and how to actually implement them. We present learning from a practice-based case study of conflict management in the Amarakaeri Communal Reserve in the Peruvian Amazon that aimed to develop natural resource governance institutions and build stakeholder capacity, including of indigenous groups, to navigate existing conflict resolution mechanisms. Through applying good practices in conservation conflict management and collaborative governance, we generated important lessons on the practical considerations involved in collaborative conservation. These lessons, while specific to our case, could be applied to a variety of protected areas facing complex social-ecological systems dynamics and wicked problems.
An accurate extraction of physiological and physical signals from human skin is crucial for health monitoring, disease prevention, and treatment. Recent advances in wearable bioelectronics directly ...embedded to the epidermal surface are a promising solution for future epidermal sensing. However, the existing wearable bioelectronics are susceptible to motion artifacts as they lack proper adhesion and conformal interfacing with the skin during motion. Here, we present ultra-conformal, customizable, and deformable drawn-on-skin electronics, which is robust to motion due to strong adhesion and ultra-conformality of the electronic inks drawn directly on skin. Electronic inks, including conductors, semiconductors, and dielectrics, are drawn on-demand in a freeform manner to develop devices, such as transistors, strain sensors, temperature sensors, heaters, skin hydration sensors, and electrophysiological sensors. Electrophysiological signal monitoring during motion shows drawn-on-skin electronics' immunity to motion artifacts. Additionally, electrical stimulation based on drawn-on-skin electronics demonstrates accelerated healing of skin wounds.
Network slicing is a powerful paradigm for network operators to support use cases with widely diverse requirements atop a common infrastructure. As 5G standards are completed, and commercial ...solutions mature, operators need to start thinking about how to integrate network slicing capabilities in their assets, so that customer-facing solutions can be made available in their portfolio. This integration is, however, not an easy task, due to the heterogeneity of assets that typically exist in carrier networks. In this regard, 5G commercial networks may consist of a number of domains, each with a different technological pace, and built out of products from multiple vendors, including legacy network devices and functions. These multi-technology, multi-vendor and brownfield features constitute a challenge for the operator, which is required to deploy and operate slices across all these domains in order to satisfy the end-to-end nature of the services hosted by these slices. In this context, the only realistic option for operators is to introduce slicing capabilities progressively, following a phased approach in their roll-out. The purpose of this paper is to precisely help designing this kind of plan, by means of a technology radar. The radar identifies a set of solutions enabling network slicing on the individual domains, and classifies these solutions into four rings, each corresponding to a different timeline: (i) as-is ring, covering today’s slicing solutions; (ii) deploy ring, corresponding to solutions available in the short term; (iii) test ring, considering medium-term solutions; and (iv) explore ring, with solutions expected in the long run. This classification is done based on the technical availability of the solutions, together with the foreseen market demands. The value of this radar lies in its ability to provide a complete view of the slicing landscape with one single snapshot, by linking solutions to information that operators may use for decision making in their individual go-to-market strategies.
This paper explores the specialized knowledge mobilized by a mathematics teacher in the selection and use of examples for teaching sequences. Taking an experimental case study approach, we analyse ...the examples deployed in a series of third-year secondary level lessons on sequences and identify the different knowledge subdomains activated according to the mathematics teachers' specialized knowledge analytical model. We will analyse active and passive examples, pointing out the mathematical entity that is being exemplified and the aspect of this entity which is being emphasized by the example. The results identify the different subdomains and categories which are drawn on in the selection and use of examples, along with the various interconnections across knowledge subdomains which interact in the process.
Assembly of recombinant multiprotein systems requires multiple culturing and purification steps that scale linearly with the number of constituent proteins. This problem is particularly pronounced in ...the preparation of the 34 proteins involved in transcription and translation systems, which are fundamental biochemistry tools for reconstitution of cellular pathways ex vivo. Here, we engineer synthetic microbial consortia consisting of between 15 and 34 Escherichia coli strains to assemble the 34 proteins in a single culturing, lysis, and purification procedure. The expression of these proteins is controlled by synthetic genetic modules to produce the proteins at the correct ratios. We show that the pure multiprotein system is functional and reproducible, and has low protein contaminants. We also demonstrate its application in the screening of synthetic promoters and protease inhibitors. Our work establishes a novel strategy for producing pure translation machinery, which may be extended to the production of other multiprotein systems.
Edge cloud computing is a crucial enabler for applications or network services with stringent communication requirements in the 5G networks and beyond era. Although edge compute resources contribute ...to a significant portion of end-to-end performance (e.g., delay), the involved performance trade-offs in relation to the utilized virtualization technologies and application functions are not yet thoroughly investigated. In this context, we study the performance dynamics of alternative edge cloud technologies, including different unikernel flavors, container builds, and implementations of exemplary Web services. Our experiments do not target identifying a single best option, rather than the involved performance trade-offs with respect to both service and infrastructure viewpoints as well as realistic edge cloud tasks, including on service operation, cloud resource or service elasticity, dynamic resource allocation and removal. We provide insights gained from a relevant extensive comparative evaluation based on a novel edge cloud experimentation infrastructure. Our experimental results inspired a conceptual edge cloud orchestration platform and its basic design guidelines, i.e., mixing and matching heterogeneous edge cloud virtual entities with particular operational or performance requirements.
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