1,869 research outputs found

    Supporting novel home network management interfaces with Openflow and NOX

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    The Homework project has examined redesign of existing home network infrastructures to better support the needs and requirements of actual home users. Integrating results from several ethnographic studies, we have designed and built a home networking platform providing detailed per-flow measurement and management capabilities supporting several novel management interfaces. This demo specifically shows these new visualization and control interfaces, and describes the broader benefits of taking an integrated view of the networking infrastructure, realised through our router's augmented measurement and control APIs. Aspects of this work have been published: the Homework Database in Internet Management (IM) 2011 and implications of the ethnographic results are to appear at the SIGCOMM W-MUST workshop 2011. Separate, more detailed expositions of the interface elements and system performance and implications are currently under submission at other venues. A partial code release is already available and we anticipate fuller public beta release by Q4 2011

    Enabling the new economic actor: data protection, the digital economy, and the Databox

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    This paper offers a sociological perspective on data protection regulation and its relevance to design. From this perspective, proposed regulation in Europe and the USA seeks to create a new economic actor—the consumer as personal data trader—through new legal frameworks that shift the locus of agency and control in data processing towards the individual consumer or “data subject”. The sociological perspective on proposed data regulation recognises the reflexive relationship between law and the social order, and the commensurate needs to balance the demand for compliance with the design of computational tools that enable this new economic actor. We present the Databox model as a means of providing data protection and allowing the individual to exploit personal data to become an active player in the emerging data economy.The authors acknowledge the support of the EPSRC, Grants EP/M001636/1, EP/M02315X/1, EP/N028260/1, and EU FP7 Grant 611001.This is the final version of the article. It first appeared from [PUBLISHER] via http://dx.doi.org/10.1007/s00779-016-0939-

    Evaluating techniques for sampling stream crayfish (paranephrops planifrons)

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    We evaluated several capture and analysis techniques for estimating abundance and size structure of freshwater crayfish (Paranephrops planifrons) (koura) from a forested North Island, New Zealand stream to provide a methodological basis for future population studies. Direct observation at night and collecting with baited traps were not considered useful. A quadrat sampler was highly biased toward collecting small individuals. Handnetting at night and estimating abundances using the depletion method were not as efficient as handnetting on different dates and analysing by a mark-recapture technique. Electrofishing was effective in collecting koura from different habitats and resulted in the highest abundance estimates, and mark-recapture estimates appeared to be more precise than depletion estimates, especially if multiple recaptures were made. Handnetting captured more large crayfish relative to electrofishing or the quadrat sampler

    Supporting novel home network management interfaces with Openflow and NOX

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    The Homework project has examined redesign of existing home network infrastructures to better support the needs and requirements of actual home users. Integrating results from several ethnographic studies, we have designed and built a home networking platform providing detailed per-flow measurement and management capabilities supporting several novel management interfaces. This demo specifically shows these new visualization and control interfaces, and describes the broader benefits of taking an integrated view of the networking infrastructure, realised through our router's augmented measurement and control APIs. Aspects of this work have been published: the Homework Database in Internet Management (IM) 2011 and implications of the ethnographic results are to appear at the SIGCOMM W-MUST workshop 2011. Separate, more detailed expositions of the interface elements and system performance and implications are currently under submission at other venues. A partial code release is already available and we anticipate fuller public beta release by Q4 2011

    The Aminoalkylindole BML-190 Negatively Regulates Chitosan Synthesis via the Cyclic AMP/Protein Kinase A1 Pathway in Cryptococcus neoformans

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    Cryptococcus neoformans can cause fatal meningoencephalitis in patients with AIDS or other immunocompromising conditions. Current antifungals are suboptimal to treat this disease; therefore, novel targets and new therapies are needed. Previously, we have shown that chitosan is a critical component of the cryptococcal cell wall and is required for survival in the mammalian host and that chitosan deficiency results in rapid clearance from the mammalian host. We had also identified several specific proteins that were required for chitosan biosynthesis, and we hypothesize that screening for compounds that inhibit chitosan biosynthesis would identify additional genes/proteins that influence chitosan biosynthesis. To identify these compounds, we developed a robust and novel cell-based flow cytometry screening method to identify small-molecule inhibitors of chitosan production. We screened the ICCB Known Bioactives library and identified 8 compounds that reduced chitosan in C. neoformans We used flow cytometry-based counterscreens and confirmatory screens, followed by a biochemical secondary screen to refine our primary screening hits to 2 confirmed hits. One of the confirmed hits that reduced chitosan content was the aminoalkylindole BML-190, a known inverse agonist of mammalian cannabinoid receptors. We demonstrated that BML-190 likely targets the C. neoformans G-protein-coupled receptor Gpr4 and, via the cyclic AMP (cAMP)/protein kinase A (PKA) signaling pathway, contributes to an intracellular accumulation of cAMP that results in decreased chitosan. Our discovery suggests that this approach could be used to identify additional compounds and pathways that reduce chitosan biosynthesis and could lead to potential novel therapeutics against C. neoformans IMPORTANCE Cryptococcus neoformans is a fungal pathogen that kills approximately 200,000 people every year. The cell wall is an essential organelle that protects fungi from the environment. Chitosan, the deacetylated form of chitin, has been shown to be an essential component of the cryptococcal cell wall during infection of a mammalian host. In this study, we screened a set of 480 compounds, which are known to have defined biological activities, for activity that reduced chitosan production in C. neoformans Two of these compounds were confirmed using an alternative method of measuring chitosan, and one of these was demonstrated to impact the cAMP signal transduction pathway. This work demonstrates that the cAMP pathway regulates chitosan biosynthesis in C. neoformans and validates that this screening approach could be used to find potential antifungal agents

    Accountable Internet of Things? Outline of the IoT databox model

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    © 2017 IEEE. This paper outlines the IoT Databox model as a means of making the Internet of Things (IoT) accountable to individuals. Accountability is a key to building consumer trust and mandated in data protection legislation. We briefly outline the 'external' data subject accountability requirement specified in actual legislation in Europe and proposed legislation in the US, and how meeting requirement this turns on surfacing the invisible actions and interactions of connected devices and the social arrangements in which they are embedded. The IoT Databox model is proposed as an in principle means of enabling accountability and providing individuals with the mechanisms needed to build trust in the IoT

    Forced Rayleigh Scattering Studies of Tracer Diffusion in a Nematic Liquid Crystal: The Relevance of Complementary Gratings

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    We have employed forced Rayleigh scattering (FRS) to study the diffusion of an azo tracer molecule (methyl red) through a nematic liquid crystal (5CB). This system was first investigated in an important study by Hara et al. (Japan. J. Appl. Phys. 23, 1420 [1984]). Since that time, it has become clear that the presence of complementary ground-state and photoproduct FRS gratings can result in nonexponential profiles, and that complementary-grating effects are significant even when "minor" deviations from exponential decay are observed. We have investigated the methyl red/5CB system in order to evaluate the possible effects of complementary gratings. In the isotropic phase, we find that the presence of complementary gratings results in a nonmonotonic FRS signal, which significantly changes the values inferred for the isotropic diffusion coefficients. As a result, the previously reported discontinuity at the nematic/isotropic transition temperature (TNI) is not present in the new data. On the other hand, in the nematic phase, the new experiments largely confirm the previous observations of single-exponential FRS decay and the non-Arrhenius temperature dependence of the nematic diffusion coefficients close to TNI. Finally, we have also observed that the decrease in the diffusion anisotropy with increasing temperature can be correlated with the 5CB nematic order parameter S(T) over the full nematic temperature range.Comment: Accepted in the Journal of Chemical Physics; to appear February 200

    The Sagnac Phase Shift suggested by the Aharonov-Bohm effect for relativistic matter beams

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    The phase shift due to the Sagnac Effect, for relativistic matter beams counter-propagating in a rotating interferometer, is deduced on the bases of a a formal analogy with the the Aharonov-Bohm effect. A procedure outlined by Sakurai, in which non relativistic quantum mechanics and newtonian physics appear together with some intrinsically relativistic elements, is generalized to a fully relativistic context, using the Cattaneo's splitting technique. This approach leads to an exact derivation, in a self-consistently relativistic way, of the Sagnac effect. Sakurai's result is recovered in the first order approximation.Comment: 18 pages, LaTeX, 2 EPS figures. To appear in General Relativity and Gravitatio

    The distribution of pond snail communities across a landscape: separating out the influence of spatial position from local habitat quality for ponds in south-east Northumberland, UK

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    Ponds support a rich biodiversity because the heterogeneity of individual ponds creates, at the landscape scale, a diversity of habitats for wildlife. The distribution of pond animals and plants will be influenced by both the local conditions within a pond and the spatial distribution of ponds across the landscape. Separating out the local from the spatial is difficult because the two are often linked. Pond snails are likely to be affected by both local conditions, e.g. water hardness, and spatial patterns, e.g. distance between ponds, but studies of snail communities struggle distinguishing between the two. In this study, communities of snails were recorded from 52 ponds in a biogeographically coherent landscape in north-east England. The distribution of snail communities was compared to local environments characterised by the macrophyte communities within each pond and to the spatial pattern of ponds throughout the landscape. Mantel tests were used to partial out the local versus the landscape respective influences. Snail communities became more similar in ponds that were closer together and in ponds with similar macrophyte communities as both the local and the landscape scale were important for this group of animals. Data were collected from several types of ponds, including those created on nature reserves specifically for wildlife, old field ponds (at least 150 years old) primarily created for watering livestock and subsidence ponds outside protected areas or amongst coastal dunes. No one pond type supported all the species. Larger, deeper ponds on nature reserves had the highest numbers of species within individual ponds but shallow, temporary sites on farm land supported a distinct temporary water fauna. The conservation of pond snails in this region requires a diversity of pond types rather than one idealised type and ponds scattered throughout the area at a variety of sites, not just concentrated on nature reserves

    Personal data management with the databox: What's inside the box?

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    We are all increasingly the subjects of data collection and processing systems that use data generated both about and by us to provide and optimise a wide range of services. Means for others to collect and process data that concerns each of us -- often referred to possessively as "your data" -- are only increasing with the long-heralded advent of the Internet of Things just the latest example. As a result, means to enable personal data management is generally recognised as a pressing societal issue. We have previously proposed that one such means might be realised by the Databox, a collection of physical and cloud-hosted software components that provide for an individual data subject to manage, log and audit access to their data by other parties. In this paper we elaborate on this proposal, describing the software architecture we are developing, and the current status of a prototype implementation. We conclude with a brief discussion of Databox's limitations
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