1,039 research outputs found

    Free Regions of Sensor Nodes

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    We introduce the notion of free region of a node in a sensor network. Intuitively, a free region of a node is the connected set of points R in its neighborhood such that the connectivity of the network remains the same when the node is moved to any point in R. We characterize several properties of free regions and develop an efficient algorithm for computing them. We capture free region in terms of related notions called in-free region and out-free region. We present an O(n2) algorithm for constructing the free region of a node, where n is the number of nodes in the network

    AAU-BOT1:a platform for studying dynamic, life-like walking

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    This paper describes the development of the humanoid robot AAU-BOT1. The purpose of the robot is to investigate human-like walking and in this connection, test prosthetic limbs. AAU-BOT1 has been designed with modularity in mind making it possible to replace, e.g. the lower leg to test transfemoral or transtibial prosthesis or orthosis. Recorded motion data from a male test person, along with approximated inertial and mass properties, were used to determine necessary joint torques in human walking which was used as design parameters for the robot. The robot has 19 degrees of freedom (DoF), 17 actuated and 2 unactuated acting as passive toe joints. The project was granted 60,000 Euro, and to keep development costs below this, the development and instrumentation was carried out by three groups of master students from the Department of Mechanical Engineering (ME) and the Department of Electronic Systems at Aalborg University and supported by the Department of Health Sciences and Technology (HST). To further reduce the cost, the robot uses off-the-shelf hardware which also reduced the time from idea to practical implementation. The result is a low-cost humanoid robot fully assembled and equipped with sensors ready to take its first steps

    Translation Representations and Scattering By Two Intervals

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    Studying unitary one-parameter groups in Hilbert space (U(t),H), we show that a model for obstacle scattering can be built, up to unitary equivalence, with the use of translation representations for L2-functions in the complement of two finite and disjoint intervals. The model encompasses a family of systems (U (t), H). For each, we obtain a detailed spectral representation, and we compute the scattering operator, and scattering matrix. We illustrate our results in the Lax-Phillips model where (U (t), H) represents an acoustic wave equation in an exterior domain; and in quantum tunneling for dynamics of quantum states

    SILAC-MS Based Characterization of LPS and Resveratrol Induced Changes in Adipocyte Proteomics:Resveratrol as Ameliorating Factor on LPS Induced Changes

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    Adipose tissue inflammation is believed to play a pivotal role in the development obesity-related morbidities such as insulin resistance. However, it is not known how this (low-grade) inflammatory state develops. It has been proposed that the leakage of lipopolysaccharides (LPS), originating from the gut microbiota, through the gut epithelium could drive initiation of inflammation. To get a better understanding of which proteins and intracellular pathways are affected by LPS in adipocytes, we performed SILAC proteomic analysis and identified proteins that were altered in expression. Furthermore, we tested the anti-inflammatory compound resveratrol. A total of 927 proteins were quantified by the SILAC method and of these 57- and 64 were significantly up- and downregulated by LPS, respectively. Bioinformatic analysis (GO analysis) revealed that the upregulated proteins were especially involved in the pathways of respiratory electron transport chain and inflammation. The downregulated proteins were especially involved in protein glycosylation. One of the latter proteins, GALNT2, has previously been described to regulate the expression of liver lipases such as ANGPTL3 and apoC-III affecting lipid metabolism. Furthermore, LPS treatment reduced the protein levels of the insulin sensitizing adipokine, adiponectin, and proteins participating in the final steps of triglyceride- and cholesterol synthesis. Generally, resveratrol opposed the effect induced by LPS and, as such, functioning as an ameliorating factor in disease state. Using an unbiased proteomic approach, we present novel insight of how the proteome is altered in adipocytes in response to LPS as seen in obesity. We suggest that LPS partly exerts its detrimental effects by altering glycosylation processes of the cell, which is starting to emerge as important posttranscriptional regulators of protein expression. Furthermore, resveratrol could be a prime candidate in ameliorating dysfunctioning adipose tissue induced by inflammatory stimulation

    The role of nanoparticle structure and morphology in the dissolution kinetics and nutrient release of nitrate‑doped calcium phosphate nanofertilizers

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    Bio-inspired synthetic calcium phosphate (CaP) nanoparticles (NPs), mimicking the mineral component of bone and teeth, are emergent materials for sustainable applications in agriculture. These sparingly soluble salts show self-inhibiting dissolution processes in undersaturated aqueous media, the control at the molecular and nanoscale levels of which is not fully elucidated. Understanding the mechanisms of particle dissolution is highly relevant to the efcient delivery of macronutrients to the plants and crucial for developing a valuable synthesis-by-design approach. It has also implications in bone (de)mineralization processes. Herein, we shed light on the role of size, morphology and crystallinity in the dissolution behaviour of CaP NPs and on their nitrate doping for potential use as (P,N)-nanofertilizers. Spherical fully amorphous NPs and apatite-amorphous nanoplatelets (NPLs) in a core-crown arrangement are studied by combining forefront Small-Angle and Wide-Angle X-ray Total Scattering (SAXS and WAXTS) analyses. ­Ca2+ ion release rates difer for spherical NPs and NPLs demonstrating that morphology plays an active role in directing the dissolution kinetics. Amorphous NPs manifest a rapid loss of nitrates governed by surface-chemistry. NPLs show much slower release, paralleling that of ­Ca2+ ions, that supports both detectable nitrate incorporation in the apatite structure and dissolution from the core basal faces.Fondazione Cariplo 2016-0648FEDER/Ministerio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion (FEDER/MCIU/AEI, Spain) through the project NanoVIT RTI-2018-095794-A-C22FEDER/Ministerio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion (FEDER/MCIU/AEI, Spain) through the project NanoSmart RYC-2016-21042FEDER/MCIU/AEI within the Juan de la Cierva Program (JdC2017
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