301 research outputs found

    Gumsense - a high power low power sensor node

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    The development of increasingly complex algorithms for sensor networks has made it difficult for researchers to implement their design on typical sensor network hardware with limited computing resources. The demands on hardware can also mean that small microcontrollers are not the ideal platform for testing computationally and/or memory intensive algorithms. Researchers would also like access to high level programming languages and a wider range of open source libraries. To address this problem we have designed and implemented an architecture, Gumsense which combines a low power micro-controller (8MHz MSP430) with a powerful processor (100-600MHz ARM) on a Gumstix board running Linux. This Open Embedded OS supports a wide variety of programming languages, package management and development tools. A similar hybrid approach was also used in the LEAP platform. The microcontroller wakes up frequently to manage tasks such as activating sensors and gathering data. The intended use-case is to power-up the ARM board and storage only during the brief periods it is needed, for example performing computation or communication

    Investigation of Ejection Releases of an MB-1 Rocket from a 0.04956-Scaled Model of the Convair F-106A Airplane at Several Mach Numbers and Simulated Altitudes

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    As a continuation of an investigation of the ejection release characteristics of an internally carried MB-1 rocket in the Convair F-106A airplane, fin modifications at additional Mach numbers and simulated altitudes have been studied in the 27- by 27-inch preflight jet of the Langley Pilotless Aircraft Research Station at Wallops Island, Va. The MB-1 rocket was ejected with fins open, fins closed, fins closed with a shroud around the fins, and fins folded with a "boattail" placed in between the fins. Dynamically scaled models (0.0^956 scale) were tested at simulated altitudes of 12,000, 18,850, and 27,500 feet at subsonic Mach numbers and at 18,850, 27,500, and 40,000 feet for Mach numbers of 1-39, 1-59, and 1.98. Successful ejections can be obtained for over 10 store diameters from release point by the use of a shroud around the folded fins with the proper ejection velocity and nose-down pitching moment at release. In one case investigated it was found desirable to close off the front one-third of the bomb bay. It appeared that the fins should be opened after release and within 5 "to 6 rocket diameters if no modifications are made on the rocket. An increase in fuselage angle of attack caused higher nose-up pitch rates after release

    The Impact of Doctoral Study on University Lecturers’ Construction of Self within a changing Higher Education policy context

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    This paper explores the impact of lectures’ individual current doctoral study on their own and collective constructions of self in a changing Higher Education (HE) policy context. It focuses on how lecturers, drawn from a professional knowledge background, make sense of new institutional requirements for new lectures to have doctorates. The lecturers themselves, through ‘facilitated collaborative auto-ethnography’, generate the substantial data and analysis for this research. This study exposes the enormous pressure of the doctorate on their lives and reveals different ways in which they resist particular forms of language, affiliations and positioning within their institution. However, of particular significance in this study is their own agency and collective voice, through using their developing cultural tools of research to ‘be’ researchers, in and beyond their own doctoral studies, in order to understand their own changing identities within HE. The study therefore reveals complex, contradictory and unexpected responses to HE policy

    Author Correction: Long-term field comparison of multiple low-cost particulate matter sensors in an outdoor urban environment

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    Correction to: Scientific Reports https://doi.org/10.1038/s41598-019-43716-3, published online 16 May 2019. This Article contains a typographical error in the Acknowledgements section. “Natural Environmental Research Council grant number [NE/L002531/1]” should read: “Natural Environment Research Council: NE/N012070/1”

    Genome analysis of a simultaneously predatory and prey-independent, novel Bdellovibrio bacteriovorus from the River Tiber, supports in silico predictions of both ancient and recent lateral gene transfer from diverse bacteria

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    Background: Evolution equipped Bdellovibrio bacteriovorus predatory bacteria to invade other bacteria, digesting and replicating, sealed within them thus preventing nutrient-sharing with organisms in the surrounding environment. Bdellovibrio were previously described as “obligate predators” because only by mutations, often in gene bd0108, are 1 in ~1x107 of predatory lab strains of Bdellovibrio converted to prey-independent growth. A previous genomic analysis of B. bacteriovorus strain HD100 suggested that predatory consumption of prey DNA by lytic enzymes made Bdellovibrio less likely than other bacteria to acquire DNA by lateral gene transfer (LGT). However the Doolittle and Pan groups predicted, in silico, both ancient and recent lateral gene transfer into the B. bacteriovorus HD100 genome. Results: To test these predictions, we isolated a predatory bacterium from the River Tiber- a good potential source of LGT as it is rich in diverse bacteria and organic pollutants- by enrichment culturing with E. coli prey cells. The isolate was identified as B. bacteriovorus and named as strain Tiberius. Unusually, this Tiberius strain showed simultaneous prey-independent growth on organic nutrients and predatory growth on live prey. Despite the prey-independent growth, the homolog of bd0108 did not have typical prey-independent-type mutations. The dual growth mode may reflect the high carbon content of the river, and gives B. bacteriovorus Tiberius extended non-predatory contact with the other bacteria present. The HD100 and Tiberius genomes were extensively syntenic despite their different cultured-terrestrial/freshly-isolated aquatic histories; but there were significant differences in gene content indicative of genomic flux and LGT. Gene content comparisons support previously published in silico predictions for LGT in strain HD100 with substantial conservation of genes predicted to have ancient LGT origins but little conservation of AT-rich genes predicted to be recently acquired. Conclusions: The natural niche and dual predatory, and prey-independent growth of the B. bacteriovorus Tiberius strain afforded it extensive non-predatory contact with other marine and freshwater bacteria from which LGT is evident in its genome. Thus despite their arsenal of DNA-lytic enzymes; Bdellovibrio are not always predatory in natural niches and their genomes are shaped by acquiring whole genes from other bacteria

    An analytical approach to characterize morbidity profile dissimilarity between distinct cohorts using electronic medical records

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    AbstractWe describe a two-stage analytical approach for characterizing morbidity profile dissimilarity among patient cohorts using electronic medical records. We capture morbidities using the International Statistical Classification of Diseases and Related Health Problems (ICD-9) codes. In the first stage of the approach separate logistic regression analyses for ICD-9 sections (e.g., “hypertensive disease” or “appendicitis”) are conducted, and the odds ratios that describe adjusted differences in prevalence between two cohorts are displayed graphically. In the second stage, the results from ICD-9 section analyses are combined into a general morbidity dissimilarity index (MDI). For illustration, we examine nine cohorts of patients representing six phenotypes (or controls) derived from five institutions, each a participant in the electronic MEdical REcords and GEnomics (eMERGE) network. The phenotypes studied include type II diabetes and type II diabetes controls, peripheral arterial disease and peripheral arterial disease controls, normal cardiac conduction as measured by electrocardiography, and senile cataracts
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