Active networking : one view of the past, present, and future

All distributed computing systems face the architectural question of the location (and nature) of programmability in the telecommunications networks, computers, and other peripheral devices comprising them. The perspective of this paper is that network elements should be as programmable as possible, to enable the most flexible distributed computing systems. There has been a persistent confluence among operating systems, programming languages, networking and distributed systems. We demonstrate how these interactions led to what is called active networking , and in the spirit of vox audita perit, littera scripta manet (the spoken word perishes, but the written word remains), include an account of how it was made to happen. Lessons are drawn both from the broader research agenda, and the specific goals pursued in the SwitchWare project. We speculate on likely futures for active networking

Chunks in PLAN: Language Support for Programs as Packets

Chunks are a programming construct in PLAN, the Packet Language for Active Networks, comprised of a code segment and a suspended function call. In PLAN, chunks provide support for encapsulation and other packet programming techniques. This paper begins by explaining the semantics and implementation of chunks. We proceed, using several PLAN source code examples, to demonstrate the usefulness of chunks for micro-protocols, asynchronous adaptations, and as units of authentication granularity

Crizotinib inhibits NF2-associated schwannoma through inhibition of focal adhesion kinase 1

Neurofibromatosis type 2 (NF2) is a dominantly inherited autosomal disease characterized by schwannomas of the 8th cranial nerve. The NF2 tumor suppressor gene encodes for Merlin, a protein implicated as a suppressor of multiple cellular signaling pathways. To identify potential drug targets in NF2-associated malignancies we assessed the consequences of inhibiting the tyrosine kinase receptor MET. We identified crizotinib, a MET and ALK inhibitor, as a potent inhibitor of NF2-null Schwann cell proliferation in vitro and tumor growth in vivo. To identify the target/s of crizotnib we employed activity-based protein profiling (ABPP), leading to identification of FAK1 (PTK2) as the relevant target of crizotinib inhibition in NF2-null schwannoma cells. Subsequent studies confirm that inhibition of FAK1 is sufficient to suppress tumorigenesis in animal models of NF2 and that crizotinib-resistant forms of FAK1 can rescue the effects of treatment. These studies identify a FDA approved drug as a potential treatment for NF2 and delineate the mechanism of action in NF2-null Schwann cells

SwitchWare: Accelerating Network Evolution (White Paper)

We propose the development of a set of software technologies ( SwitchWare ) which will enable rapid development and deployment of new network services. The key insight is that by making the basic network service selectable on a per user (or even per packet) basis, the need for formal standardization is eliminated. Additionally, by making the basic network service programmable, the deployment times, today constrained by capital funding limitations, are tremendously reduced (to the order of software distribution times). Finally, by constructing an advanced, robust programming environment, even the service development time can be reduced. A SwitchWare switch consists of input and output ports controlled by a software-programmable element; programs are contained in sequences of messages sent to the SwitchWare switch\u27s input ports, which interpret the messages as programs. We call these Switchlets . This accelerates the pace of network evolution, as evolving user needs can be immediately reflected in the network infrastructure. Immediate reconfigurability enhances the adaptability of the network infrastructure in the face of unexpected situations. We call a network built from SwitchWare switches an active network

An Experimental Evaluation of Rate Adaptation for Multi-Antenna Systems

Abstract—Increasingly wireless networks use multi-antenna nodes as in IEEE 802.11n and 802.16. The Physical layer (PHY) in such systems may use the antennas to provide multiple streams of data (spatial multiplexing) or to increase the robustness of fewer streams. These physical layers also provide support for sending packets at different rates by changing the modulation and coding of transmissions. Rate adaptation is the problem of choosing the best transmission mode for the current channel and in these systems requires choosing both the level of spatial multiplexing and the modulation and coding. Hydra is an experimental wireless network node prototype in which both the MAC and PHY are highly programmable. Hydra’s PHY is essentially the 802.11n PHY, and currently supports two antennas and the same modulations and codings as 802.11n. Because of limitations of our hardware platform, th

Doctoral students’ well-being in United Kingdom Business Schools::A Survey of Personal Experience and Support Mechanisms

We present the perspectives on mental well-being of 63 Doctoral students (DS) undertaking a PhD in business schools in United Kingdom (UK) universities. Utilising a cross-sectional survey, the aims of this study are to 1. Capture business and management doctoral students' (DSs) views on their mental well-being and the factors that affect it. 2. Critically review the influence of the business school learning environment on doctoral student well-being. 3. Reflect on the effectiveness of business schools’ support for the well-being of doctoral students. Findings indicate that many business school doctoral students viewed their mental well-being negatively and more than half considered their personal well-being as their own problem. Personal and interpersonal factors caused a very high percentage of their negative mental well-being issues, with the majority of research supervisors being viewed as a positive support. However, in business school doctoral training programmes, respondents reported minimal input on managing and understanding their personal well-being, despite research which correlates faculty and departmental support for well-being and PhD completion. In the light of these findings we suggest that individual business schools should review their training curriculum for doctoral students to prevent over-reliance on the supervisory team and offer more formal training on managing mental well-being

Physiological stress response, reflex impairment and delayed mortality of white sturgeon Acipenser transmontanus exposed to simulated fisheries stressors

White sturgeon (Acipenser transmontanus) are the largest freshwater fish in North America and a species exposed to widespread fishing pressure. Despite the growing interest in recreational fishing for white sturgeon, little is known about the sublethal and lethal impacts of angling on released sturgeon. In summer (July 2014, mean water temperature 15.3°C) and winter (February 2015, mean water temperature 6.6°C), captive white sturgeon (n = 48) were exposed to a combination of exercise and air exposure as a method of simulating an angling event. After the stressor, sturgeon were assessed for a physiological stress response, and reflex impairments were quantified to determine overall fish vitality (i.e. capacity for survival). A physiological stress response occurred in all sturgeon exposed to a fishing-related stressor, with the magnitude of the res

Collagen organization deposited by fibroblasts encapsulated in pH responsive methacrylated alginate hydrogels

The pH of dermal wounds shifts from neutral during the inflammatory phase to slightly basic in the tissue remodeling phase. Stage specific wound treatment can be developed using environmentally responsive alginate hydrogels. The chemistry of these networks dictates swelling behavior. Here, we fabricated alginate hydrogels using chain growth, step growth, and combined mixed mode gelation methods to crosslink methacrylated alginate (ALGMA) and gain control over swelling responses. Methacrylation of the alginate network was confirmed through NMR spectroscopy. Strontium cations were introduced to fabricate stiffer, dually crosslinked hydrogels. Dual crosslinking significantly decreased the swelling response over the pH range of 3–9 for step growth and chain growth hydrogels, with no impact on mixed mode hydrogels. The extent of crosslinking altered the hydrogel degradation profiles under accelerated degradation conditions. Encapsulated NIH/3T3 fibroblasts in the different ALGMA hydrogels remained viable with greater cell proliferation in the stiffer gels. Collagen organization deposited by the NIH/3T3 fibroblasts was monitored using second harmonic generation (SHG) microscopy and was influenced by the crosslinking mechanism. Ionic chain growth and ionic mixed mode crosslinked ALGMA hydrogels caused relatively isotropic collagen organization, particularly 10 days post‐cell encapsulation. Principal component analysis (PCA) was employed to uncover correlations between the observed properties. The ability of these environmentally responsive gels to induce isotropic collagen and respond to pH changes means they hold promise as phase specific wound dressings