1,031 research outputs found
Quantitative evaluation of polymer gel dosimeters by broadband ultrasound attenuation
Ultrasound has been examined previously as an alternative readout method for irradiated polymer gel dosimeters, with authors reporting varying dose response to ultrasound transmission measurements. In this current work we extend previous work to measure the broadband ultrasound attenuation (BUA) response of irradiated PAGAT gel dosimeters, using a novel ultrasound computed tomography system
A method to simultaneously determine reduction in PAH dissolved concentrations and bioaccessibility in carbon amended soils
Effect of activated carbon, biochar and compost on the desorption and the biodegradation of low concentrations of phenanthrene sorbed to different soils
Scaling Behavior of Human Locomotor Activity Amplitude: Association with Bipolar Disorder
Scale invariance is a feature of complex biological systems, and abnormality of multi-scale behaviour may serve as an indicator of pathology. The hypothalamic suprachiasmatic nucleus (SCN) is a major node in central neural networks responsible for regulating multi-scale behaviour in measures of human locomotor activity. SCN also is implicated in the pathophysiology of bipolar disorder (BD) or manic-depressive illness, a severe, episodic disorder of mood, cognition and behaviour. Here, we investigated scaling behaviour in actigraphically recorded human motility data for potential indicators of BD, particularly its manic phase. A proposed index of scaling behaviour (Vulnerability Index [VI]) derived from such data distinguished between: [i] healthy subjects at high versus low risk of mood disorders; [ii] currently clinically stable BD patients versus matched controls; and [iii] among clinical states in BD patients
A High-resolution Adaptive Moving Mesh Hydrodynamic Algorithm
An algorithm for simulating self-gravitating cosmological astrophysical
fluids is presented. The advantages include a large dynamic range,
parallelizability, high resolution per grid element and fast execution speed.
The code is based on a finite volume flux conservative
Total-Variation-Diminishing (TVD) scheme for the shock capturing hydro, and an
iterative multigrid solver for the gravity. The grid is a time dependent field,
whose motion is described by a generalized potential flow. Approximately
constant mass per cell can be obtained, providing all the advantages of a
Lagrangian scheme. The grid deformation combined with appropriate limiting and
smoothing schemes guarantees a regular and well behaved grid geometry, where
nearest neighbor relationships remain constant. The full hydrodynamic fluid
equations are implemented in the curvilinear moving grid, allowing for
arbitrary fluid flow relative to the grid geometry. This combination retains
all the advantages of the grid based schemes including high speed per fluid
element and a rapid gravity solver.
The current implementation is described, and empirical simulation results are
presented. Accurate execution speed calculations are given in terms of floating
point operations per time step per grid cell. This code is freely available to
the community.Comment: 53 pages including 14 figures, submitted to ApJ
Iron biogeochemistry across marine systems progress from the past decade
Based on an international workshop (Gothenburg, 14â16 May 2008), this review article aims to combine interdisciplinary knowledge from coastal and open ocean research on iron biogeochemistry. The major scientific findings of the past decade are structured into sections on natural and artificial iron fertilization, iron inputs into coastal and estuarine systems, colloidal iron and organic matter, and biological processes. Potential effects of global climate change, particularly ocean acidification, on iron biogeochemistry are discussed. The findings are synthesized into recommendations for future research areas
Review: âGimme fiveâ: future challenges in multiple sclerosis. ECTRIMS Lecture 2009
This article is based on the ECTRIMS lecture given at the 25th ECTRIMS meeting which was held in DĂŒsseldorf, Germany, from 9 to 12 September 2009. Five challenges have been identified: (1) safeguarding the principles of medical ethics; (2) optimizing the risk/benefit ratio; (3) bridging the gap between multiple sclerosis and experimental autoimmune encephalitis; (4) promoting neuroprotection and repair; and (5) tailoring multiple sclerosis therapy to the individual patient. Each of these challenges will be discussed and placed in the context of current research into the pathogenesis and treatment of multiple sclerosis
Phytoscreening and phytoextraction of heavy metals at Danish polluted sites using willow and poplar trees
The main purpose of this study was to determine typical concentrations of heavy metals (HM) in wood from willows and poplars, in order to test the feasibility of phytoscreening and phytoextraction of HM. Samples were taken from one strongly, one moderately, and one slightly polluted site and from three reference sites. Wood from both tree species had similar background concentrations at 0.5 mg kg(â1) for cadmium (Cd), 1.6 mg kg(â1) for copper (Cu), 0.3 mg kg(â1) for nickel (Ni), and 25 mg kg(â1) for zinc (Zn). Concentrations of chromium (Cr) and lead (Pb) were below or close to detection limit. Concentrations in wood from the highly polluted site were significantly elevated, compared to references, in particular for willow. The conclusion from these results is that tree coring could be used successfully to identify strongly heavy metal-polluted soil for Cd, Cu, Ni, Zn, and that willow trees were superior to poplars, except when screening for Ni. Phytoextraction of HMs was quantified from measured concentration in wood at the most polluted site. Extraction efficiencies were best for willows and Cd, but below 0.5 % over 10 years, and below 1ââ° in 10 years for all other HMs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11356-013-2085-z) contains supplementary material, which is available to authorized users
A Design for the Interface Between a Battery Storage and Charging Unit, and a Medium Voltage DC (MVDC) Bus, as Part of an Integrated Propulsion System (IPS) in the All Electric Ship (AES)
Abstract In this paper we present the design of a rechargeable battery storage device for use in an all-electric ship. The purpose of this device is to provide power of predictable quality to selected equipment. In addition a recharging unit is proposed for recharging the battery from the ship's electric bus
Experimental aluminum pathology in rabbits: effects of hydrophilic and lipophilic compounds.
Aluminum lactate [Al(lact)3] (hydrophilic, hydrolytically unstable) and aluminum acetylacetonate [Al(acae)3] (lipophilic, hydrolytically stable) were tested as potential toxicants to rabbits upon IV administration both as aqueous solutions and as liposome suspensions. Both chemicals behaved as cardiotoxic agents when administered as aqueous solutions, but Al(acae)3 was at least two orders of magnitude more active than Al(lact)3. Al(acae)3, but not Al(lact)3, caused myocardial infarcts resembling those in humans (with contraction bands) at doses as low as 0.24 mg/kg body weight, as well as a prominent acanthocytosis. Al(lact)3, when administered as a liposome suspension, was about 300 times more toxic than in aqueous solution, although cardiac damage was not infarctual in character. Both chemical and physical speciation of aluminum(III) thus play an essential role in determining the toxicity of the metal
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