402 research outputs found

    Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

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    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota

    A Low Cost Remote Sensing System Using PC and Stereo Equipment

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    A system using a personal computer, speaker, and a microphone is used to detect objects, and make crude measurements using a carrier modulated by a pseudorandom noise (PN) code. This system can be constructed using a personal computer and audio equipment commonly found in the laboratory or at home, or more sophisticated equipment that can be purchased at reasonable cost. We demonstrate its value as an instructional tool for teaching concepts of remote sensing and digital signal processing.Comment: Accepted for publication in American Journal of Physic

    The Effects of Combined Movement and Storytelling Intervention on Motor Skills in South Asian and White Children Aged 5–6 Years Living in the United Kingdom

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    Early motor development has an important role in promoting physical activity (PA) during childhood and across the lifespan. Children from South Asian backgrounds are less active and have poorer motor skills, thus identifying the need for early motor skill instruction. This study examines the effect of a movement and storytelling intervention on South Asian children’s motor skills. Following ethics approval and consent, 39 children (46% South Asian) participated in a 12-week movement and storytelling intervention. Pre and post, seven motor skills (run, jump, throw, catch, stationary dribble, roll, and kick) were assessed using Children’s Activity and Movement in Preschool Study protocol. At baseline, South Asian children had poorer performance of motor skills. Following the intervention, all children improved their motor skills, with a bigger improvement observed for South Asian children. Early intervention provided remedial benefits to delays in motor skills and narrowed the motor skills gap in ethnic groups

    Modeling Quantum Optical Components, Pulses and Fiber Channels Using OMNeT++

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    Quantum Key Distribution (QKD) is an innovative technology which exploits the laws of quantum mechanics to generate and distribute unconditionally secure cryptographic keys. While QKD offers the promise of unconditionally secure key distribution, real world systems are built from non-ideal components which necessitates the need to model and understand the impact these non-idealities have on system performance and security. OMNeT++ has been used as a basis to develop a simulation framework to support this endeavor. This framework, referred to as "qkdX" extends OMNeT++'s module and message abstractions to efficiently model optical components, optical pulses, operating protocols and processes. This paper presents the design of this framework including how OMNeT++'s abstractions have been utilized to model quantum optical components, optical pulses, fiber and free space channels. Furthermore, from our toolbox of created components, we present various notional and real QKD systems, which have been studied and analyzed.Comment: Published in: A. F\"orster, C. Minkenberg, G. R. Herrera, M. Kirsche (Eds.), Proc. of the 2nd OMNeT++ Community Summit, IBM Research - Zurich, Switzerland, September 3-4, 201

    ADS-B Classification using Multivariate Long Short-term Memory–fully Convolutional Networks and Data Reduction Techniques

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    Researchers typically increase training data to improve neural net predictive capabilities, but this method is infeasible when data or compute resources are limited. This paper extends previous research that used long short-term memory–fully convolutional networks to identify aircraft engine types from publicly available automatic dependent surveillance-broadcast (ADS-B) data. This research designs two experiments that vary the amount of training data samples and input features to determine the impact on the predictive power of the ADS-B classification model. The first experiment varies the number of training data observations from a limited feature set and results in 83.9% accuracy (within 10% of previous efforts with only 25% of the data). The findings show that feature selection and data quality lead to higher classification accuracy than data quantity. The second experiment accepted all ADS-B feature combinations and determined that airspeed, barometric pressure, and vertical speed had the most impact on aircraft engine type prediction

    ‘Closing the Gap’ at the Peril of Widening the Void: Implications of the Ontario Ministry of Education’s Policy for Aboriginal Education

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    There is a crisis relevant to the publicly funded education of Aboriginal students in Ontar‐ io. This article, which presents the details of the crisis, analyzes recent policy statements released by the Ontario Ministry of Education designed to address that crisis. By defining the nature of this critical juncture, presenting how these policies may be “widening the void” rather than “closing the gap,” and offering opportunities to respond by improving the capabilities of teachers to enact those policies in their classrooms, the authors appeal to school boards, faculty associations, as well as Deans of Education, to act decisively to sup‐ port Aboriginal self‐determination. Key words: Aboriginal student achievement, Aboriginal languages and student identity, teacher education Une crise sĂ©vit en ce moment au sujet de l’enseignement autochtone en Ontario financĂ©e Ă  mĂȘme les deniers publics. Dans cet article, les auteurs dĂ©crivent les dĂ©tails de la crise et analysent des Ă©noncĂ©s de politique rĂ©cents du ministĂšre de l’Éducation de l’Ontario visant Ă  dĂ©nouer la crise. Tout en se penchant sur la nature mĂȘme de ce problĂšme Ă©pineux, en expli‐ quant comment ces politiques risquent de « creuser le vide » au lieu de « combler l’écart » et en offrant des possibilitĂ©s de rĂ©ponse par l’amĂ©lioration des capacitĂ©s des enseignants de mettre ces politiques en application dans leurs classes, les auteurs font appel aux commis‐ sions scolaires, aux associations universitaires et aux doyens d’éducation afin qu’ils sou‐ tiennent activement l’autodĂ©termination des autochtones. Mots clĂ©s : rĂ©ussite des Ă©lĂšves autochtones, langues autochtones et identitĂ© des Ă©lĂšves, for‐ mation Ă  l’enseignement.

    Evaluation Criteria for Selecting NoSQL Databases in a Single Box Environment

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    In recent years, NoSQL database systems have become increasingly popular, especially for big data, commercial applications. These systems were designed to overcome the scaling and flexibility limitations plaguing traditional relational database management systems (RDBMSs). Given NoSQL database systems have been typically implemented in large-scale distributed environments serving large numbers of simultaneous users across potentially thousands of geographically separated devices, little consideration has been given to evaluating their value within single-box environments. It is postulated some of the inherent traits of each NoSQL database type may be useful, perhaps even preferable, regardless of scale. Thus, this paper proposes criteria conceived to evaluate the usefulness of NoSQL systems in small-scale single-box environments. Specifically, key value, document, column family, and graph database are discussed with respect to the ability of each to provide CRUD transactions in a single-box environment
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