Bisimulation equivalence of differential-algebraic systems

NASA Astrophysics Data System (ADS)

Megawati, Noorma Yulia; Schaft, Arjan van der

2018-01-01

In this paper, the notion of bisimulation relation for linear input-state-output systems is extended to general linear differential-algebraic (DAE) systems. Geometric control theory is used to derive a linear-algebraic characterisation of bisimulation relations, and an algorithm for computing the maximal bisimulation relation between two linear DAE systems. The general definition is specialised to the case where the matrix pencil sE - A is regular. Furthermore, by developing a one-sided version of bisimulation, characterisations of simulation and abstraction are obtained.

An empirical review of antimalarial quality field surveys: the importance of characterising outcomes.

PubMed

Grech, James; Robertson, James; Thomas, Jackson; Cooper, Gabrielle; Naunton, Mark; Kelly, Tamsin

2018-01-05

For decades, thousands of people have been dying from malaria infections because of poor-quality medicines (PQMs). While numerous efforts have been initiated to reduce their presence, PQMs are still risking the lives of those seeking treatment. This review addresses the importance of characterising results of antimalarial medicine field surveys based upon the agreement of clearly defined definitions. Medicines found to be of poor quality can be falsified or counterfeit, substandard or degraded. The distinction between these categories is important as each category requires a different countermeasure. To observe the current trends in the reporting of field surveys, a systematic literature search of six academic databases resulted in the quantitative analysis of 61 full-text journal articles. Information including sample size, sampling method, geographical regions, analytical techniques, and characterisation conclusions was observed for each. The lack of an accepted uniform reporting system has resulted in varying, incomplete reports, which may not include important information that helps form effective countermeasures. The programmes influencing medicine quality such as prequalification, procurement services, awareness and education can be supported with the information derived from characterised results. The implementation of checklists such as the Medicine Quality Assessment Reporting Guidelines will further strengthen the battle against poor-quality antimalarials. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, characterisation, and in vitro cellular uptake kinetics of nanoprecipitated poly(2-methacryloyloxyethyl phosphorylcholine)- b-poly(2-(diisopropylamino)ethyl methacrylate) (MPC-DPA) polymeric nanoparticle micelles for nanomedicine applications

NASA Astrophysics Data System (ADS)

Salvage, Jonathan P.; Smith, Tia; Lu, Tao; Sanghera, Amendeep; Standen, Guy; Tang, Yiqing; Lewis, Andrew L.

2016-10-01

Nanoscience offers the potential for great advances in medical technology and therapies in the form of nanomedicine. As such, developing controllable, predictable, and effective, nanoparticle-based therapeutic systems remains a significant challenge. Many polymer-based nanoparticle systems have been reported to date, but few harness materials with accepted biocompatibility. Phosphorylcholine (PC) based biomimetic materials have a long history of successful translation into effective commercial medical technologies. This study investigated the synthesis, characterisation, nanoprecipitation, and in vitro cellular uptake kinetics of PC-based polymeric nanoparticle micelles (PNM) formed by the biocompatible and pH responsive block copolymer poly(2-methacryloyloxyethyl phosphorylcholine)- b-poly(2-(diisopropylamino)ethyl methacrylate) (MPC-DPA). Atom transfer radical polymerisation (ATRP), and gel permeation chromatography (GPC) were used to synthesise and characterise the well-defined MPC100-DPA100 polymer, revealing organic GPC, using evaporative light scatter detection, to be more accurate than aqueous GPC for this application. Subsequent nanoprecipitation investigations utilising photon correlation spectroscopy (PCS) revealed PNM size increased with polymer concentration, and conferred Cryo-stability. PNM diameters ranged from circa 64-69 nm, and increased upon hydrophobic compound loading, circa 65-71 nm, with loading efficiencies of circa 60 % achieved, whilst remaining monodisperse. In vitro studies demonstrated that the PNM were of low cellular toxicity, with colony formation and MTT assays, utilising V79 and 3T3 cells, yielding comparable results. Investigation of the in vitro cellular uptake kinetics revealed rapid, 1 h, cellular uptake of MPC100-DPA100 PNM delivered fluorescent probes, with fluorescence persistence for 48 h. This paper presents the first report of these novel findings, which highlight the potential of the system for nanomedicine application development.

Characterisation of a major phytoplankton bloom in the River Thames (UK) using flow cytometry and high performance liquid chromatography.

PubMed

Moorhouse, H L; Read, D S; McGowan, S; Wagner, M; Roberts, C; Armstrong, L K; Nicholls, D J E; Wickham, H D; Hutchins, M G; Bowes, M J

2018-05-15

Recent river studies have observed rapid phytoplankton dynamics, driven by diurnal cycling and short-term responses to storm events, highlighting the need to adopt new high-frequency characterisation methods to understand these complex ecological systems. This study utilised two such analytical methods; pigment analysis by high performance liquid chromatography (HPLC) and cell counting by flow cytometry (FCM), alongside traditional chlorophyll spectrophotometry and light microscopy screening, to characterise the major phytoplankton bloom of 2015 in the River Thames, UK. All analytical techniques observed a rapid increase in chlorophyll a concentration and cell abundances from March to early June, caused primarily by a diatom bloom. Light microscopy identified a shift from pennate to centric diatoms during this period. The initial diatom bloom coincided with increased HPLC peridinin concentrations, indicating the presence of dinoflagellates which were likely to be consuming the diatom population. The diatom bloom declined rapidly in early June, coinciding with a storm event. There were low chlorophyll a concentrations (by both HPLC and spectrophotometric methods) throughout July and August, implying low biomass and phytoplankton activity. However, FCM revealed high abundances of pico-chlorophytes and cyanobacteria through July and August, showing that phytoplankton communities remain active and abundant throughout the summer period. In combination, these techniques are able to simultaneously characterise a wider range of phytoplankton groups, with greater certainty, and provide improved understanding of phytoplankton functioning (e.g. production of UV inhibiting pigments by cyanobacteria in response to high light levels) and ecological status (through examination of pigment degradation products). Combined HPLC and FCM analyses offer rapid and cost-effective characterisation of phytoplankton communities at appropriate timescales. This will allow a more-targeted use of light microscopy to capture phytoplankton peaks or to investigate periods of rapid community succession. This will lead to greater system understanding of phytoplankton succession in response to biogeochemical drivers. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Spatio-temporal characterisation of a 100 kHz 24 W sub-3-cycle NOPCPA laser system

NASA Astrophysics Data System (ADS)

Witting, Tobias; Furch, Federico J.; Vrakking, Marc J. J.

2018-04-01

In recent years, OPCPA and NOPCPA laser systems have shown the potential to supersede Ti:sapphire plus post-compression based laser systems to drive next generation attosecond light sources via direct amplification of few-cycle pulses to high pulse energies at high repetition rates. In this paper, we present a sub 3-cycle, 100 kHz, 24 W NOPA laser system and characterise its spatio-temporal properties using the SEA-F-SPIDER technique. Our results underline the importance of spatio-temporal diagnostics for these emerging laser systems.

Characterising soil surface roughness with a frequency modulated polarimetric radar

NASA Astrophysics Data System (ADS)

Seeger, Manuel; Gronz, Oliver; Beiske, Joshua; Klein, Tobias

2014-05-01

Soil surface roughness is considered crucial for soil erosion as it determines the effective surface exposed to the raindrop impact. It regulates surface runoff velocity and it causes runoff concentration. But a comprehensive characterisation of the shape of the soils' surface is still difficult to achieve. Photographic systems and terrestrial laser-scanning are nowadays able to generate high resolution DEMs, but the derivation of roughness parameters is still not clear. Spaceborne radar systems are used for about 3 decades for earth survey. Spatial soil moisture distribution, ice sheet monitoring and earth-wide topographic survey are the main objectives of these radar systems, working generally with frequencies <10 GHz. Contrasting with this, technologies emitting frequencies up to 77 GHz are generally used for object tracking purposes. But it is known, that the reflection characteristics, such as intensity and polarisation, strongly depend on the properties of the target object. A new design of a frequency modulated continuous wave radar, emitting a right hand shaped circular polarization and receiving both polarization directions, right and left-hand shaped, is tested here for its ability to detect and quantify different surface roughness. The reflection characteristics of 4 different materials 1) steel, 2) sand (0,5-1 mm), 3) fine (2-4 mm) and 4) coarse (15-30 mm) rock-fragments and different roughness as well as moisture content are analysed. In addition, the signals are taken at 2 different angles to the soil's surface (90° and 70°). For quantification of the roughness, a photographic method (Structure-from-Motion) is applied to generate a detailed DEM and random roughness (RR) is calculated. To characterise the radar signal, different ratios of the reflected channels and polarisations are calculated. The signals show differences for all substrates, also clearly visible between sand and fine rock fragments, despite a wavelength of 1 cm of the electromagnetic waves. A systematic change of the signals with changing roughness is also observed. Measurements show a significant influence of the angle of observation. Soil moisture shows also an influence on the reflected signal, but is quite well differentiable to the effects of the shape of the soil's surface. The results show that polarimetric radar technology may be suitable to characterise the surface of soils, but still faces a big lack of knowledge on how to quantify and differentiate the different signals, how to handle variable observation angles, and finally how to characterise roughness.

Electro-Optic Characterisation of Extremely Wide Bandwidth Electrical Signals

DTIC Science & Technology

1993-02-01

In this report an ultrafast electro - optic sampling system suitable for applications such as device characterisation is described. The aperture time of the sampler is calculated to be about 290 fs, implying an attainable device bandwidth in excess of 300 GHz. The sampler was characterised using a test pulse with approximately 12 GHz of frequency content, and the results compared to those obtained from an 18 GHz digital sampling oscilloscope. Signal Processing, Bandwidth, Frequencies, Oscilloscopes.

Characterisation of embroidered 3D electrodes by use of anthraquinone-1,5-disulfonic acid as probe system

NASA Astrophysics Data System (ADS)

Aguiló-Aguayo, Noemí; Bechtold, Thomas

2014-05-01

New electrode designs are required for electrochemical applications such as batteries or fuel cells. Embroidered 3D Cu porous electrodes with a geometric surface of 100 cm2 are presented and characterised by means of the anthraquinone-1,5-disfulfonic acid (AQDS2-) redox system in alkaline solution. The electrochemical behaviour of the 3D electrode is established by the comparison of cyclic voltammetry responses using a micro cell and a 100 cm2 plane Cu-plate electrode. Dependencies of the peak currents and peak-to-peak potential separation on scan rate and AQDS2- concentration are studied. The AQDS2- characterisation is also performed by means of spectroelectrochemical experiments.

Separation and characterisation of five polar herbicides using countercurrent chromatography with detection by negative ion electrospray ionisation mass spectrometry.

PubMed

Kidwell, H; Jones, J J; Games, D E

2001-01-01

Five polar herbicides were separated and characterised using high-speed analytical countercurrent chromatography (HSACCC) in conjunction with online electrospray mass spectrometry (ESI-MS). The countercurrent chromatography used a standard isocratic biphasic solvent system of hexane/ethyl acetate/methanol/water in reverse phase to effect the separation of these five environmentally important compounds. The chromatograph was coupled to a triple quadrupole mass spectrometer via a standard electrospray liquid chromatography interface that was able to give mass spectra in negative ion mode of each compound. Limits of detection are reported for this series of compounds along with representative negative ion ESI-MS data and calibrations for the separation. Copyright 2001 John Wiley & Sons, Ltd.

Universal test system for system embedded optical interconnect

NASA Astrophysics Data System (ADS)

Pitwon, R.; Wang, K.; Immonen, M.; Schröder, H.; Neitz, M.

2018-02-01

We introduce a universal test and measurement system allowing comparative characterisation of optical transceivers, board-to-board optical connectors and both embedded and passive optical circuit boards. The system comprises a test enclosure with interlocking and interchangeable test cards, allowing different technologies spanning different Technology Readiness Levels to be both characterised alone and in combination with other technologies. They form part of the open test design standards portfolio developed on the FP7 PhoxTroT and H2020 COSMICC projects and allow testing on a common test platform.

Spatial and temporal analyses for multiscale monitoring of landslides: Examples from Northern Ireland

NASA Astrophysics Data System (ADS)

Bell, Andrew; McKinley, Jennifer; Hughes, David

2013-04-01

Landslides in the form of debris flows, large scale rotational features and composite mudflows impact transport corridors cutting off local communities and in some instances result in loss of life. This study presents landslide monitoring methods used for predicting and characterising landslide activity along transport corridors. A variety of approaches are discussed: desk based risk assessment of slopes using Geographical Information Systems (GIS); Aerial LiDAR surveys and Terrestrial LiDAR monitoring and field instrumentation of selected sites. A GIS based case study is discussed which provides risk assessment for the potential of slope stability issues. Layers incorporated within the system include Digital Elevation Model (DEM), slope, aspect, solid and drift geology and groundwater conditions. Additional datasets include consequence of failure. These are combined within a risk model, presented as likelihoods of failure. This integrated spatial approach for slope risk assessment provides the user with a preliminary risk assessment of sites. An innovative "Flexviewer" web-based server interface allows users to view data without needing advanced GIS techniques to gather information about selected areas. On a macro landscape scale, Aerial LiDAR (ALS) surveys are used for the characterisation of landslides from the surrounding terrain. DEMs are generated along with terrain derivatives: slope, curvature and various measures of terrain roughness. Spatial analysis of terrain morphological parameters allow characterisation of slope stability issues and are used to predict areas of potential failure or recently failure terrain. On a local scale ground monitoring approaches are employed for the monitoring of changes in selected slopes using ALS and risk assessment approaches. Results are shown from on-going bimonthly Terrestrial LiDAR (TLS) monitoring of the slope within a site specific geodectically referenced network. This has allowed a classification of changes in the slopes with DEMs of difference showing areas of recent movement, erosion and deposition. In addition, changes in the structure of the slope characterised by DEM of difference and morphological parameters in the form of roughness, slope and curvature measures are progressively linked to failures indicated from temporal DEM monitoring. Preliminary results are presented for a case site at Straidkilly Point, Glenarm, Co. Antrim, Northern Ireland, illustrating multiple approaches to the spatial and temporal monitoring of landslides. These indicate how spatial morphological approaches and risk assessment frameworks coupled with TLS monitoring and field instrumentation enable characterisation and prediction of potential areas of slope stability issues. On site weather instrumentation and piezometers document changes in pore water pressures resulting in site-specific information with geotechnical observations parameterised within the temporal LiDAR monitoring. This provides a multifaceted approach to the characterisation and analysis of slope stability issues. The presented methodology of multiscale datasets and surveying approaches utilising spatial parameters and risk index mapping enables a more comprehensive and effective prediction of landslides resulting in effective characterisation and remediation strategies.

Electrochemical characterisation and anodic stripping voltammetry at mesoporous platinum rotating disc electrodes.

PubMed

Lozano-Sanchez, Pablo; Elliott, Joanne M

2008-02-01

Using the technique of liquid crystal templating a rotating disc electrode (RDE) was modified with a high surface area mesoporous platinum film. The surface area of the electrode was characterised by acid voltammetry, and found to be very high (ca. 86 cm(2)). Acid characterisation of the electrode produced distorted voltammograms was interpreted as being due to the extremely large surface area which produced a combination of effects such as localised pH change within the pore environment and also ohmic drop effects. Acid voltammetry in the presence of two different types of surfactant, namely Tween 20 and Triton X-100, suggested antifouling properties associated with the mesoporous deposit. Further analysis of the modified electrode using a redox couple in solution showed typical RDE behaviour although extra capacitive currents were observed due to the large surface area of the electrode. The phenomenon of underpotential deposition was exploited for the purpose of anodic stripping voltammetry and results were compared with data collected for microelectrodes. Underpotential deposition of metal ions at the mesoporous RDE was found to be similar to that at conventional platinum electrodes and mesoporous microelectrodes although the rate of surface coverage was found to be slower at a mesoporous RDE. It was found that a mesoporous RDE forms a suitable system for quantification of silver ions in solution.

A novel textile characterisation approach using an embedded sensor system and segmented textile manipulation

NASA Astrophysics Data System (ADS)

Fial, Julian; Carosella, Stefan; Langheinz, Mario; Wiest, Patrick; Middendorf, Peter

2018-05-01

This paper investigates the application of sensors on carbon fibre textiles for the purpose of textile characterisation and draping process optimisation. The objective is to analyse a textile's condition during the draping operation and actively manipulate boundary conditions in order to create better preform qualities. Various realisations of textile integrated sensors are presented, focusing on the measurement of textile strain. Furthermore, a complex textile characterisation approach is presented where these sensors shall be implemented in.

Characterisation of nanomaterial hydrophobicity using engineered surfaces

NASA Astrophysics Data System (ADS)

Desmet, Cloé; Valsesia, Andrea; Oddo, Arianna; Ceccone, Giacomo; Spampinato, Valentina; Rossi, François; Colpo, Pascal

2017-03-01

Characterisation of engineered nanomaterials (NMs) is of outmost importance for the assessment of the potential risks arising from their extensive use. NMs display indeed a large variety of physico-chemical properties that drastically affect their interaction with biological systems. Among them, hydrophobicity is an important property that is nevertheless only slightly covered by the current physico-chemical characterisation techniques. In this work, we developed a method for the direct characterisation of NM hydrophobicity. The determination of the nanomaterial hydrophobic character is carried out by the direct measurement of the affinity of the NMs for different collectors. Each collector is an engineered surface designed in order to present specific surface charge and hydrophobicity degrees. Being thus characterised by a combination of surface energy components, the collectors enable the NM immobilisation with surface coverage in relation to their hydrophobicity. The experimental results are explained by using the extended DLVO theory, which takes into account the hydrophobic forces acting between NMs and collectors.

Polycarbonate-Based Blends for Optical Non-linear Applications.

PubMed

Stanculescu, F; Stanculescu, A

2016-12-01

This paper presents some investigations on the optical and morphological properties of the polymer (matrix):monomer (inclusion) composite materials obtained from blends of bisphenol A polycarbonate and amidic monomers. For the preparation of the composite films, we have selected monomers characterised by a maleamic acid structure and synthesised them starting from maleic anhydride and aniline derivatives with -COOH, -NO2, -N(C2H5)2 functional groups attached to the benzene ring. The composite films have been deposited by spin coating using a mixture of two solutions, one containing the matrix and the other the inclusion, both components of the composite system being dissolved in the same solvent. The optical transmission and photoluminescence properties of the composite films have been investigated in correlation with the morphology of the films. The scanning electron microscopy and atomic force microscopy have revealed a non-uniform morphology characterised by the development of two distinct phases. We have also investigated the generation of some optical non-linear (ONL) phenomena in these composite systems. The composite films containing as inclusions monomers characterised by the presence of one -COOH or two -NO2 substituent groups to the aromatic nucleus have shown the most intense second-harmonic generation (SHG). The second-order optical non-linear coefficients have been evaluated for these films, and the effect of the laser power on the ONL behaviour of these materials has also been emphasised.

Polycarbonate-Based Blends for Optical Non-linear Applications

NASA Astrophysics Data System (ADS)

Stanculescu, F.; Stanculescu, A.

2016-02-01

This paper presents some investigations on the optical and morphological properties of the polymer (matrix):monomer (inclusion) composite materials obtained from blends of bisphenol A polycarbonate and amidic monomers. For the preparation of the composite films, we have selected monomers characterised by a maleamic acid structure and synthesised them starting from maleic anhydride and aniline derivatives with -COOH, -NO2, -N(C2H5)2 functional groups attached to the benzene ring. The composite films have been deposited by spin coating using a mixture of two solutions, one containing the matrix and the other the inclusion, both components of the composite system being dissolved in the same solvent. The optical transmission and photoluminescence properties of the composite films have been investigated in correlation with the morphology of the films. The scanning electron microscopy and atomic force microscopy have revealed a non-uniform morphology characterised by the development of two distinct phases. We have also investigated the generation of some optical non-linear (ONL) phenomena in these composite systems. The composite films containing as inclusions monomers characterised by the presence of one -COOH or two -NO2 substituent groups to the aromatic nucleus have shown the most intense second-harmonic generation (SHG). The second-order optical non-linear coefficients have been evaluated for these films, and the effect of the laser power on the ONL behaviour of these materials has also been emphasised.

Characterisation of the properties of a negative hydrogen ion beam by several beam diagnostic techniques

NASA Astrophysics Data System (ADS)

Maurizio, R.; Fantz, U.; Bonomo, F.; Serianni, G.

2016-06-01

The beam properties of the BATMAN negative ion source, which is the prototype of one module of the source for the ITER neutral beam injection system, are characterised by means of three diagnostic techniques: beam emission spectroscopy (BES), the experimental calorimeter mini-STRIKE and a copper calorimeter. The main beam parameters—beam divergence, homogeneity and top-bottom asymmetries—are studied in different operational scenarios: with different magnetic filter field setups, source settings and with different gases (hydrogen or deuterium). Among all dependences, the influence of the magnetic field configuration on the beam and the evolution of the beam features during some conditioning days are investigated in detail. Data show that the stronger the filter field in the beam region, the higher the beam top-bottom asymmetry—likely a v× B effect. During the conditioning of the source, such vertical beam asymmetry increases as well, suggesting an inhomogeneous H -production at the first grid of the extraction system.

The osteogenic response of mesenchymal stem cells to an injectable PLGA bone regeneration system.

PubMed

Curran, Judith M; Fawcett, Sandra; Hamilton, Lloyd; Rhodes, Nicholas P; Rahman, Cheryl V; Alexander, Morgan; Shakesheff, Kevin; Hunt, John A

2013-12-01

The enrichment of substrates/surfaces with selected functional groups, methyl (-CH3), allyl amine (-NH2), allyl alcohol (-OH) and acrylic acid (-COOH), can be used to trigger mesenchymal stem (MSC) cell differentiation into specified lineages, minimising the need for exogenous biological supplementation. We present the successful translation of this research phenomenon to an injectable two phase injectable PLGA system, utilising plasma techniques, for the repair of bone defects. Modified microspheres were characterised using water contact angel (WCA), X-ray Photon Spectroscopy (XPS) and scanning electron microscopy (SEM). When cultured in contact with MSCs in vitro, the ability of the modified particles, within the 2 phase system, to induce differentiation was characterised using quantitative assays for cell viability and histological analysis for key markers of differentiation throughout the entirety of the three dimensional scaffold. Biological analysis proved that selected modified microspheres have the ability to induce MSC osteogenic (-NH2 modified scaffolds) and chondrogenic (-OH modified scaffolds) differentiation throughout the entirety of the formed scaffold. Therefore optimised plasma modification of microspheres is an effective tool for the production of injectable systems for the repair of bone and cartilage defects. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterising the influence of atmospheric mixing state on Urban Heat Island Intensity using Radon-222

NASA Astrophysics Data System (ADS)

Chambers, Scott D.; Podstawczyńska, Agnieszka; Williams, Alastair G.; Pawlak, Włodzimierz

2016-12-01

Characterisation of the effects of varying atmospheric mixing states (stability) in urban climate studies has historically been hampered by problems associated with the complexity of the urban environment, representativity of measurement techniques, and the logistical and financial burdens of maintaining multiple long-term comprehensive measurement sites. These shortcomings, together with a lack of a consistent measurement approach, have limited our ability to understand the physical processes contributing to the urban heat island effect. In this study, we analyse 4 years of continuous hourly near-surface meteorological and atmospheric radon data from an urban-rural site pair in central Poland. A recently-developed radon-based stability classification technique, previously developed for urban pollution characterisation, is employed to characterise the Urban Heat Island Intensity (UHII) and other climatic factors over the full diurnal cycle by season and atmospheric mixing state. By characterising the UHII over a range of atmospheric mixing states in a statistically robust way, this technique provides an effective tool for assessing the efficacy of mitigation measures for urban climate effects in a consistent way over timescales of years to decades. The consistency of approach, ease of application, and unprecedented clarity of findings, provide a strong argument for atmospheric radon observations to be included as part of the 'standard measurement suite' for urban climate monitoring networks for non-coastal cities.

Congenital Extrahepatic Portosystemic Shunts: Spectrum of Findings on Ultrasound, Computed Tomography, and Magnetic Resonance Imaging

PubMed Central

Gupta, Pankaj; Sinha, Anindita; Sodhi, Kushaljit Singh; Lal, Anupam; Debi, Uma; Thapa, Babu R.; Khandelwal, Niranjan

2015-01-01

Congenital extrahepatic portosystemic shunt (CEPS) is a rare disorder characterised by partial or complete diversion of portomesenteric blood into systemic veins via congenital shunts. Type I is characterised by complete lack of intrahepatic portal venous blood flow due to an end to side fistula between main portal vein and the inferior vena cava. Type II on the other hand is characterised by partial preservation of portal blood supply to liver and side to side fistula between main portal vein or its branches and mesenteric, splenic, gastric, and systemic veins. The presentation of these patients is variable. Focal liver lesions, most commonly nodular regenerative hyperplasia, are an important clue to the underlying condition. This pictorial essay covers imaging characteristics in abdominopelvic region. PMID:26858845

Development of Novel DNA Cleavage Systems Based on Copper Complexes. Synthesis and Characterisation of Cu(II) Complexes of Hydroxyflavones

PubMed Central

el Amrani, F. Ben-Allal; Perelló, L.; Torres, L.

2000-01-01

Copper(II) complexes of several hydroxyflavones were prepared and characterised through their physico-chemical properties. The nuclease activity of three synthesised complexes is reported. These copper(II) complexes present more nuclease activity than the ligands and the copper(II) ion. PMID:18475969

Diprosopus tetraophthalmus: CT as a complement to autopsy.

PubMed

Laor, T; Stanek, J; Leach, J L

2012-01-01

Diprosopus is the rarest form of conjoined twinning. This anomaly is characterised by craniofacial duplication to varying degrees and is associated with anomalies of the central nervous, cardiac, respiratory and musculoskeletal systems. We present an infant characterised as diprosopus tetraophthalmus who underwent post-mortem CT, which served as a highly useful complement to autopsy.

Assessment of electrochemical properties of a biogalvanic system for tissue characterisation

PubMed Central

Chandler, J.H.; Culmer, P.R.; Jayne, D.G.; Neville, A.

2015-01-01

Biogalvanic characterisation is a promising method for obtaining health-specific tissue information. However, there is a dearth of understanding in the literature regarding the underlying galvanic cell, electrode reactions and their controlling factors which limits the application of the technique. This work presents a parametric electrochemical investigation into a zinc–copper galvanic system using salt (NaCl) solution analogues at physiologically-relevant concentrations (1.71, 17.1 & 154 mM). The potential difference at open cell, closed cell maximum current and the internal resistance (based on published characterisation methods) were measured. Additionally, independent and relative polarisation scans of the electrodes were performed to improve understanding of the system. Our findings suggest that the prominent reaction at the cathode is that of oxygen-reduction, not hydrogen-evolution. Results indicate that cell potentials are influenced by the concentration of dissolved oxygen at low currents and maximum closed cell currents are limited by the rate of oxygen diffusion to the cathode. Characterised internal resistance values for the salt solutions did not correspond to theoretical values at the extremes of concentration (1.71 and 154 mM) due to electrode resistance and current limitation. Existing biogalvanic models do not consider these phenomena and should be improved to advance the technique and its practical application. PMID:25460609

Characterising Dynamic Instability in High Water-Cut Oil-Water Flows Using High-Resolution Microwave Sensor Signals

NASA Astrophysics Data System (ADS)

Liu, Weixin; Jin, Ningde; Han, Yunfeng; Ma, Jing

2018-06-01

In the present study, multi-scale entropy algorithm was used to characterise the complex flow phenomena of turbulent droplets in high water-cut oil-water two-phase flow. First, we compared multi-scale weighted permutation entropy (MWPE), multi-scale approximate entropy (MAE), multi-scale sample entropy (MSE) and multi-scale complexity measure (MCM) for typical nonlinear systems. The results show that MWPE presents satisfied variability with scale and anti-noise ability. Accordingly, we conducted an experiment of vertical upward oil-water two-phase flow with high water-cut and collected the signals of a high-resolution microwave resonant sensor, based on which two indexes, the entropy rate and mean value of MWPE, were extracted. Besides, the effects of total flow rate and water-cut on these two indexes were analysed. Our researches show that MWPE is an effective method to uncover the dynamic instability of oil-water two-phase flow with high water-cut.

A review of modern approaches to the hydrodynamic characterisation of polydisperse macromolecular systems in biotechnology.

PubMed

Gillis, Richard B; Rowe, Arthur J; Adams, Gary G; Harding, Stephen E

2014-10-01

This short review considers the range of modern techniques for the hydrodynamic characterisation of macromolecules - particularly large glycosylated systems used in the food, biopharma and healthcare industries. The range or polydispersity of molecular weights and conformations presents special challenges compared to proteins. The review is aimed, without going into any great theoretical or methodological depth, to help the Industrial Biotechnologist choose the appropriate methodology or combination of methodologies for providing the detail he/she needs for particular applications.

A Versatile Strategy for the Semisynthetic Production of Ser65 Phosphorylated Ubiquitin and Its Biochemical and Structural Characterisation

PubMed Central

Han, Cong; Pao, Kuan-Chuan; Kazlauskaite, Agne; Muqit, Miratul M K; Virdee, Satpal

2015-01-01

Ubiquitin phosphorylation is emerging as an important regulatory layer in the ubiquitin system. This is exemplified by the phosphorylation of ubiquitin on Ser65 by the Parkinson's disease-associated kinase PINK1, which mediates the activation of the E3 ligase Parkin. Additional phosphorylation sites on ubiquitin might also have important cellular roles. Here we report a versatile strategy for preparing phosphorylated ubiquitin. We biochemically and structurally characterise semisynthetic phospho-Ser65-ubiquitin. Unexpectedly, we observed disulfide bond formation between ubiquitin molecules, and hence a novel crystal form. The method outlined provides a direct approach to study the combinatorial effects of phosphorylation on ubiquitin function. Our analysis also suggests that disulfide engineering of ubiquitin could be a useful strategy for obtaining alternative crystal forms of ubiquitin species thereby facilitating structural validation. PMID:26010437

A pressure and shear sensor system for stress measurement at lower limb residuum/socket interface.

PubMed

Laszczak, P; McGrath, M; Tang, J; Gao, J; Jiang, L; Bader, D L; Moser, D; Zahedi, S

2016-07-01

A sensor system for measurement of pressure and shear at the lower limb residuum/socket interface is described. The system comprises of a flexible sensor unit and a data acquisition unit with wireless data transmission capability. Static and dynamic performance of the sensor system was characterised using a mechanical test machine. The static calibration results suggest that the developed sensor system presents high linearity (linearity error ≤ 3.8%) and resolution (0.9 kPa for pressure and 0.2 kPa for shear). Dynamic characterisation of the sensor system shows hysteresis error of approximately 15% for pressure and 8% for shear. Subsequently, a pilot amputee walking test was conducted. Three sensors were placed at the residuum/socket interface of a knee disarticulation amputee and simultaneous measurements were obtained during pilot amputee walking test. The pressure and shear peak values as well as their temporal profiles are presented and discussed. In particular, peak pressure and shear of approximately 58 kPa and 27 kPa, respectively, were recorded. Their temporal profiles also provide dynamic coupling information at this critical residuum/socket interface. These preliminary amputee test results suggest strong potential of the developed sensor system for exploitation as an assistive technology to facilitate socket design, socket fit and effective monitoring of lower limb residuum health. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Diprosopus tetraophthalmus: CT as a complement to autopsy

PubMed Central

Laor, T; Stanek, J; Leach, J L

2012-01-01

Diprosopus is the rarest form of conjoined twinning. This anomaly is characterised by craniofacial duplication to varying degrees and is associated with anomalies of the central nervous, cardiac, respiratory and musculoskeletal systems. We present an infant characterised as diprosopus tetraophthalmus who underwent post-mortem CT, which served as a highly useful complement to autopsy. PMID:22190755

Characterisation

DTIC Science & Technology

2007-03-01

Characterisation. In Nanotechnology Aerospace Applications – 2006 (pp. 4-1 – 4-8). Educational Notes RTO-EN-AVT-129bis, Paper 4. Neuilly-sur-Seine, France: RTO...the Commercialisation Processes Concept IDEA Proof-of- Principle Trial Samples Engineering Verification Samples Design Verification Samples...SEIC Systems Engineering for commercialisation Design Houses, Engineering & R&D USERS & Integrators SE S U R Integrators Fabs & Wafer Processing Die

Developing SABRE as an analytical tool in NMR

NASA Astrophysics Data System (ADS)

Lloyd, Lyrelle Stacey

Work presented in this thesis centres around the application of the new hyperpolarisation technique, SABRE, within nuclear magnetic resonance spectroscopy, focusing on optimisation of the technique to characterise small organic molecules. While pyridine was employed as a model substrate, studies on a range of molecules are investigated including substituted pyridines, quinolines, thiazoles and indoles are detailed. Initial investigations explored how the properties of the SABRE catalyst effect the extent of polarisation transfer exhibited. The most important of these properties proved to be the rate constants for loss of pyridine and hydrides as these define the contact time of pyridine with the parahydrogen derived hydride ligands in the metal template. The effect of changing the temperature, solvent or concentration of substrate or catalyst are rationalised. For instance, the catalyst ICy(a) exhibits relatively slow ligand exchange rates and increasing the temperature during hyperpolarisation increases the observed signal enhancements. These studies have revealed a second polarisation transfer template can be used with SABRE in which two substrate molecules are bound. This allows the possibility of investigation of larger substrates which might otherwise be too sterically encumbered to bind. Another significant advance relates to the first demonstration that SABRE can be used in conjunction with an automated system designed with Bruker allowing the acquisition of scan averaged, phase cycled and traditional 2D spectra. The system also allowed investigations into the effect of the polarisation transfer field and application of that knowledge to collect single-scan 13C data for characterisation. The successful acquisition of 1H NOESY, 1H-1H COSY, 1H-13C 2D and ultrafast 1H-1H COSY NMR sequences is detailed for a 10 mM concentration sample, with 1H data collected for a 1 mM sample. A range of studies which aim to demonstrate the applicability of SABRE to the characterisation of small molecules and pharmaceuticals have been conducted.

Global population trends and policy options.

PubMed

Ezeh, Alex C; Bongaarts, John; Mberu, Blessing

2012-07-14

Rapid population growth is a threat to wellbeing in the poorest countries, whereas very low fertility increasingly threatens the future welfare of many developed countries. The mapping of global trends in population growth from 2005-10 shows four distinct patterns. Most of the poorest countries, especially in sub-Saharan Africa, are characterised by rapid growth of more than 2% per year. Moderate annual growth of 1-2% is concentrated in large countries, such as India and Indonesia, and across north Africa and western Latin America. Whereas most advanced-economy countries and large middle-income countries, such as China and Brazil, are characterised by low or no growth (0-1% per year), most of eastern Europe, Japan, and a few western European countries are characterised by population decline. Countries with rapid growth face adverse social, economic, and environmental pressures, whereas those with low or negative growth face rapid population ageing, unsustainable burdens on public pensions and health-care systems, and slow economic growth. Countries with rapid growth should consider the implementation of voluntary family planning programmes as their main policy option to reduce the high unmet need for contraception, unwanted pregnancies, and probirth reproductive norms. In countries with low or negative growth, policies to address ageing and very low fertility are still evolving. Further research into the potential effect of demographic policies on other social systems, social groups, and fertility decisions and trends is therefore recommended. Copyright © 2012 Elsevier Ltd. All rights reserved.

Smart Aquifer Characterisation validated using Information Theory and Cost benefit analysis

NASA Astrophysics Data System (ADS)

Moore, Catherine

2016-04-01

The field data acquisition required to characterise aquifer systems are time consuming and expensive. Decisions regarding field testing, the type of field measurements to make and the spatial and temporal resolution of measurements have significant cost repercussions and impact the accuracy of various predictive simulations. The Smart Aquifer Characterisation (SAC) research programme (New Zealand (NZ)) addresses this issue by assembling and validating a suite of innovative methods for characterising groundwater systems at the large, regional and national scales. The primary outcome is a suite of cost effective tools and procedures provided to resource managers to advance the understanding and management of groundwater systems and thereby assist decision makers and communities in the management of their groundwater resources, including the setting of land use limits that protect fresh water flows and quality and the ecosystems dependent on that fresh water. The programme has focused novel investigation approaches including the use of geophysics, satellite remote sensing, temperature sensing and age dating. The SMART (Save Money And Reduce Time) aspect of the programme emphasises techniques that use these passive cost effective data sources to characterise groundwater systems at both the aquifer and the national scale by: • Determination of aquifer hydraulic properties • Determination of aquifer dimensions • Quantification of fluxes between ground waters and surface water • Groundwater age dating These methods allow either a lower cost method for estimating these properties and fluxes, or a greater spatial and temporal coverage for the same cost. To demonstrate the cost effectiveness of the methods a 'data worth' analysis is undertaken. The data worth method involves quantification of the utility of observation data in terms of how much it reduces the uncertainty of model parameters and decision focussed predictions which depend on these parameters. Such decision focussed predictions can include many aspects of system behaviour which underpin management decisions e.g., drawdown of groundwater levels, salt water intrusion, stream depletion, or wetland water level. The value of a data type or an observation location (e.g. remote sensing data (Westerhoff 2015) or a distributed temperature sensing measurement) is greater the more it enhances the certainty with which the model is able to predict such environmental behaviour. By comparing the difference in predictive uncertainty with or without such data, the value of potential observations is assessed. This can easily be achieved using rapid linear predictive uncertainty analysis methods (Moore 2005, Moore and Doherty 2006). By assessing the tension between the cost of data acquisition and the predictive accuracy achieved by gathering these observations in a pareto analysis, the relative cost effectiveness of these novel methods can be compared with more traditional measurements (e.g. bore logs, aquifer pumping tests, and simultaneous stream loss gaugings) for a suite of pertinent groundwater management decisions (Wallis et al 2014). This comparison illuminates those field data acquisition methods which offer the best value for the specific issues managers face in any region, and also indicates the diminishing returns of increasingly large and expensive data sets. References: Wallis I, Moore C, Post V, Wolf L, Martens E, Prommer. Using predictive uncertainty analysis to optimise tracer test design and data acquisition. Journal of Hydrology 515 (2014) 191-204. Moore, C. (2005). The use of regularized inversion in groundwater model calibration and prediction uncertainty analysis. Thesis submitted for the degree of Doctor of Philosophy at The University of Queensland, Australia. Moore, C., and Doherty, D. (2005). Role of the calibration process in reducing model predictive error. Water Resources Research 41, no.5 W05050. Westerhoff RS. Using uncertainty of Penman and Penman-Monteith methods in combined satellite and ground-based evapotranspiration estimates. Remote Sensing of Environment 169, 102-112

Hydrodynamic characteristics and mixing behaviour of Sclerotium glucanicum culture fluids in an airlift reactor with an internal loop used for scleroglucan production.

PubMed

Kang, X; Wang, H; Wang, Y; Harvey, L M; McNeil, B

2001-10-01

The filamentous fungus, Sclerotium glucanicum NRRL 3006, was cultivated in a 0.008 m(3) airlift bioreactor with internal recirculation loop (ARL-IL) for production of the biopolymer, scleroglucan. The rheological behaviour of the culture fluid was characterised by measurement of the fluid consistency coefficient (K) and the flow behaviour index (n). Based on these measurements, the culture fluid changed from a low viscosity Newtonian system early in the process, to a viscous non-Newtonian (pseudoplastic) system. In addition, reactor hydrodynamics and mixing behaviour were characterised by measurement of whole mean gas hold-up (epsilon(g)), liquid re-circulation velocity (U(ld)) and mixing time (t(m)). Under identical process conditions, the effects of the viscosity of the culture fluid and air flow rate on epsilon(g), U(ld) and t(m) were examined and empirical correlations for epsilon(g), U(ld) and t(m) with both superficial velocity U(g) and consistency coefficient K were obtained and expressed separately. The correlations obtained are likely to describe the behaviour of real fungal culture fluids more accurately than previous correlations based on Newtonian or simulated non-Newtonian systems.

Microscopic Statistical Characterisation of the Congested Traffic Flow and Some Salient Empirical Features

NASA Astrophysics Data System (ADS)

Yang, Bo; Yoon, Ji Wei; Monterola, Christopher

We present large scale, detailed analysis of the microscopic empirical data of the congested traffic flow, focusing on the non-linear interactions between the components of the many-body traffic system. By implementing a systematic procedure that averages over relatively unimportant factors, we extract the effective dependence of the acceleration on the gap between the vehicles, velocity and relative velocity. Such relationship is characterised not just by a few vehicles but the traffic system as a whole. Several interesting features of the detailed vehicle-to-vehicle interactions are revealed, including the stochastic distribution of the human responses, relative importance of the non-linear terms in different density regimes, symmetric response to the relative velocity, and the insensitivity of the acceleration to the velocity within a certain gap and velocity range. The latter leads to a multitude of steady-states without a fundamental diagram. The empirically constructed functional dependence of the acceleration on the important dynamical quantities not only gives the detailed collective driving behaviours of the traffic system, it also serves as the fundamental reference for the validations of the deterministic and stochastic microscopic traffic models in the literature.

Integrated methodology for assessing the HCH groundwater pollution at the multi-source contaminated mega-site Bitterfeld/Wolfen.

PubMed

Wycisk, Peter; Stollberg, Reiner; Neumann, Christian; Gossel, Wolfgang; Weiss, Holger; Weber, Roland

2013-04-01

A large-scale groundwater contamination characterises the Pleistocene groundwater system of the former industrial and abandoned mining region Bitterfeld/Wolfen, Eastern Germany. For more than a century, local chemical production and extensive lignite mining caused a complex contaminant release from local production areas and related dump sites. Today, organic pollutants (mainly organochlorines) are present in all compartments of the environment at high concentration levels. An integrated methodology for characterising the current situation of pollution as well as the future fate development of hazardous substances is highly required to decide on further management and remediation strategies. Data analyses have been performed on regional groundwater monitoring data from about 10 years, containing approximately 3,500 samples, and up to 180 individual organic parameters from almost 250 observation wells. Run-off measurements as well as water samples were taken biweekly from local creeks during a period of 18 months. A kriging interpolation procedure was applied on groundwater analytics to generate continuous distribution patterns of the nodal contaminant samples. High-resolution geological 3-D modelling serves as a database for a regional 3-D groundwater flow model. Simulation results support the future fate assessment of contaminants. A first conceptual model of the contamination has been developed to characterise the contamination in regional surface waters and groundwater. A reliable explanation of the variant hexachlorocyclohexane (HCH) occurrence within the two local aquifer systems has been derived from the regionalised distribution patterns. Simulation results from groundwater flow modelling provide a better understanding of the future pollutant migration paths and support the overall site characterisation. The presented case study indicates that an integrated assessment of large-scale groundwater contaminations often needs more data than only from local groundwater monitoring. The developed methodology is appropriate to assess POP-contaminated mega-sites including, e.g. HCH deposits. Although HCH isomers are relevant groundwater pollutants at this site, further organochlorine pollutants are present at considerably higher levels. The study demonstrates that an effective evaluation of the current situation of contamination as well as of the related future fate development requires detailed information of the entire observed system.

The behaviour change wheel: a new method for characterising and designing behaviour change interventions.

PubMed

Michie, Susan; van Stralen, Maartje M; West, Robert

2011-04-23

Improving the design and implementation of evidence-based practice depends on successful behaviour change interventions. This requires an appropriate method for characterising interventions and linking them to an analysis of the targeted behaviour. There exists a plethora of frameworks of behaviour change interventions, but it is not clear how well they serve this purpose. This paper evaluates these frameworks, and develops and evaluates a new framework aimed at overcoming their limitations. A systematic search of electronic databases and consultation with behaviour change experts were used to identify frameworks of behaviour change interventions. These were evaluated according to three criteria: comprehensiveness, coherence, and a clear link to an overarching model of behaviour. A new framework was developed to meet these criteria. The reliability with which it could be applied was examined in two domains of behaviour change: tobacco control and obesity. Nineteen frameworks were identified covering nine intervention functions and seven policy categories that could enable those interventions. None of the frameworks reviewed covered the full range of intervention functions or policies, and only a minority met the criteria of coherence or linkage to a model of behaviour. At the centre of a proposed new framework is a 'behaviour system' involving three essential conditions: capability, opportunity, and motivation (what we term the 'COM-B system'). This forms the hub of a 'behaviour change wheel' (BCW) around which are positioned the nine intervention functions aimed at addressing deficits in one or more of these conditions; around this are placed seven categories of policy that could enable those interventions to occur. The BCW was used reliably to characterise interventions within the English Department of Health's 2010 tobacco control strategy and the National Institute of Health and Clinical Excellence's guidance on reducing obesity. Interventions and policies to change behaviour can be usefully characterised by means of a BCW comprising: a 'behaviour system' at the hub, encircled by intervention functions and then by policy categories. Research is needed to establish how far the BCW can lead to more efficient design of effective interventions.

The behaviour change wheel: A new method for characterising and designing behaviour change interventions

PubMed Central

2011-01-01

Background Improving the design and implementation of evidence-based practice depends on successful behaviour change interventions. This requires an appropriate method for characterising interventions and linking them to an analysis of the targeted behaviour. There exists a plethora of frameworks of behaviour change interventions, but it is not clear how well they serve this purpose. This paper evaluates these frameworks, and develops and evaluates a new framework aimed at overcoming their limitations. Methods A systematic search of electronic databases and consultation with behaviour change experts were used to identify frameworks of behaviour change interventions. These were evaluated according to three criteria: comprehensiveness, coherence, and a clear link to an overarching model of behaviour. A new framework was developed to meet these criteria. The reliability with which it could be applied was examined in two domains of behaviour change: tobacco control and obesity. Results Nineteen frameworks were identified covering nine intervention functions and seven policy categories that could enable those interventions. None of the frameworks reviewed covered the full range of intervention functions or policies, and only a minority met the criteria of coherence or linkage to a model of behaviour. At the centre of a proposed new framework is a 'behaviour system' involving three essential conditions: capability, opportunity, and motivation (what we term the 'COM-B system'). This forms the hub of a 'behaviour change wheel' (BCW) around which are positioned the nine intervention functions aimed at addressing deficits in one or more of these conditions; around this are placed seven categories of policy that could enable those interventions to occur. The BCW was used reliably to characterise interventions within the English Department of Health's 2010 tobacco control strategy and the National Institute of Health and Clinical Excellence's guidance on reducing obesity. Conclusions Interventions and policies to change behaviour can be usefully characterised by means of a BCW comprising: a 'behaviour system' at the hub, encircled by intervention functions and then by policy categories. Research is needed to establish how far the BCW can lead to more efficient design of effective interventions. PMID:21513547

Discovery and functional characterisation of a luqin-type neuropeptide signalling system in a deuterostome.

PubMed

Yañez-Guerra, Luis Alfonso; Delroisse, Jérôme; Barreiro-Iglesias, Antón; Slade, Susan E; Scrivens, James H; Elphick, Maurice R

2018-05-08

Neuropeptides are diverse and evolutionarily ancient regulators of physiological/behavioural processes in animals. Here we have investigated the evolution and comparative physiology of luqin-type neuropeptide signalling, which has been characterised previously in protostomian invertebrates. Phylogenetic analysis indicates that luqin-type receptors and tachykinin-type receptors are paralogous and probably originated in a common ancestor of the Bilateria. In the deuterostomian lineage, luqin-type signalling has been lost in chordates but interestingly it has been retained in ambulacrarians. Therefore, here we characterised luqin-type signalling for the first time in an ambulacrarian - the starfish Asterias rubens (phylum Echinodermata). A luqin-like neuropeptide with a C-terminal RWamide motif (ArLQ; EEKTRFPKFMRW-NH 2 ) was identified as the ligand for two luqin-type receptors in A. rubens, ArLQR1 and ArLQR2. Furthermore, analysis of the expression of the ArLQ precursor using mRNA in situ hybridisation revealed expression in the nervous system, digestive system and locomotory organs (tube feet) and in vitro pharmacology revealed that ArLQ causes dose-dependent relaxation of tube feet. Accordingly, previous studies have revealed that luqin-type signalling regulates feeding and locomotor activity in protostomes. In conclusion, our phylogenetic analysis combined with characterisation of luqin-type signalling in a deuterostome has provided new insights into neuropeptide evolution and function in the animal kingdom.

Characterising encapsulated nuclear waste using cosmic-ray muon tomography

NASA Astrophysics Data System (ADS)

Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D. G.; Johnstone, J. R.; Kaiser, R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Yang, G.; Zimmerman, C.

2015-03-01

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the U.K. Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

The characterisation of second phases in the Zr-Nb and Zr-Nb-Sn-Fe alloys: A critical review

NASA Astrophysics Data System (ADS)

Harte, Allan; Griffiths, Malcolm; Preuss, Michael

2018-07-01

The nature and evolution of the Fe environment in Zr-Nb and Zr-Nb-Sn-Fe systems is essential to alloy performance during corrosion, hardening and irradiation-induced growth. Unfortunately, there is ambiguity in the literature regarding the characterisation of secondary phases in these systems. The presence, or not, of Fe in β-Nb phase has been a source of disagreement. In ternary ZrNbFe intermetallics, identical compositions have been designated as Zr(Nb,Fe)2 or (Zr,Nb)3Fe. We show that while Zr(Nb,Fe)2 is commonly reported, it is not always justified. The cubic phase (Zr,Nb)2Fe is easily identified, but its composition is more variable after low temperature heat treatments. We demonstrate the need for correlative approaches in the assessment of phase composition, crystallography and local Fe environment under different heat treatment regimes. Irradiation effects allow us to draw clues regarding phase designation, but there is diverse behaviour under irradiation due to initial phase composition, irradiation dose rate and temperature.

"Too Withdrawn" or "Too Friendly": Considering Social Vulnerability in Two Neuro-Developmental Disorders

ERIC Educational Resources Information Center

Jawaid, A.; Riby, D. M.; Owens, J.; White, S. W.; Tarar, T.; Schulz, P. E.

2012-01-01

In some neuro-developmental disorders, the combined effect of intellectual disability and atypicalities of social cognition may put individuals at increased vulnerability in their social environment. The neuro-developmental disorders Williams syndrome, characterised by "hypersociability", and autism spectrum disorders, characterised by "social…

Novel circuit design for high-impedance and non-local electrical measurements of two-dimensional materials

NASA Astrophysics Data System (ADS)

De Sanctis, Adolfo; Mehew, Jake D.; Alkhalifa, Saad; Tate, Callum P.; White, Ashley; Woodgate, Adam R.; Craciun, Monica F.; Russo, Saverio

2018-02-01

Two-dimensional materials offer a novel platform for the development of future quantum technologies. However, the electrical characterisation of topological insulating states, non-local resistance, and bandgap tuning in atomically thin materials can be strongly affected by spurious signals arising from the measuring electronics. Common-mode voltages, dielectric leakage in the coaxial cables, and the limited input impedance of alternate-current amplifiers can mask the true nature of such high-impedance states. Here, we present an optical isolator circuit which grants access to such states by electrically decoupling the current-injection from the voltage-sensing circuitry. We benchmark our apparatus against two state-of-the-art measurements: the non-local resistance of a graphene Hall bar and the transfer characteristic of a WS2 field-effect transistor. Our system allows the quick characterisation of novel insulating states in two-dimensional materials with potential applications in future quantum technologies.

Contact force structure and force chains in 3D sheared granular systems

NASA Astrophysics Data System (ADS)

Mair, Karen; Jettestuen, Espen; Abe, Steffen

2010-05-01

Faults often exhibit accumulations of granular debris, ground up to create a layer of rock flour or fault gouge separating the rigid fault walls. Numerical simulations and laboratory experiments of sheared granular materials, suggest that applied loads are preferentially transmitted across such systems by transient force networks that carry enhanced forces. The characterisation of such features is important since their nature and persistence almost certainly influence the macroscopic mechanical stability of these systems and potentially that of natural faults. 3D numerical simulations of granular shear are a valuable investigation tool since they allow us to track individual particle motions, contact forces and their evolution during applied shear, that are difficult to view directly in laboratory experiments or natural fault zones. In characterising contact force distributions, it is important to use global structure measures that allow meaningful comparisons of granular systems having e.g. different grain size distributions, as may be expected at different stages of a fault's evolution. We therefore use a series of simple measures to characterise the structure, such as distributions and correlations of contact forces that can be mapped onto a force network percolation problem as recently proposed by Ostojic and coworkers for 2D granular systems. This allows the use of measures from percolation theory to both define and characterise the force networks. We demonstrate the application of this method to 3D simulations of a sheared granular material. Importantly, we then compare our measure of the contact force structure with macroscopic frictional behaviour measured at the boundaries of our model to determine the influence of the force networks on macroscopic mechanical stability.

Current Application of Capillary Electrophoresis in Nanomaterial Characterisation and Its Potential to Characterise the Protein and Small Molecule Corona

PubMed Central

Guggenheim, Emily J.; Briffa, Sophie M.; Thorn, James A.; Lynch, Iseult; Valsami-Jones, Eugenia

2018-01-01

Due to the increasing use and production of nanomaterials (NMs), the ability to characterise their physical/chemical properties quickly and reliably has never been so important. Proper characterisation allows a thorough understanding of the material and its stability, and is critical to establishing dose-response curves to ascertain risks to human and environmental health. Traditionally, methods such as Transmission Electron Microscopy (TEM), Field Flow Fractionation (FFF) and Dynamic Light Scattering (DLS) have been favoured for size characterisation, due to their wide-availability and well-established protocols. Capillary Electrophoresis (CE) offers a faster and more cost-effective solution for complex dispersions including polydisperse or non-spherical NMs. CE has been used to rapidly separate NMs of varying sizes, shapes, surface modifications and compositions. This review will discuss the literature surrounding the CE separation techniques, detection and NM characteristics used for the analysis of a wide range of NMs. The potential of combining CE with mass spectrometry (CE-MS) will also be explored to further expand the characterisation of NMs, including the layer of biomolecules adsorbed to the surface of NMs in biological or environmental compartments, termed the acquired biomolecule corona. CE offers the opportunity to uncover new/poorly characterised low abundance and polar protein classes due to the high ionisation efficiency of CE-MS. Furthermore, the possibility of using CE-MS to characterise the poorly researched small molecule interactions within the NM corona is discussed. PMID:29439415

Impact during equine locomotion: techniques for measurement and analysis.

PubMed

Burn, J F; Wilson, A; Nason, G P

1997-05-01

Impact is implicated in the development of several types of musculoskeletal injury in the horse. Characterisation of impact experienced during strenuous exercise is an important first step towards understanding the mechanism for injury. Measurement and analysis of large, short duration impacts is difficult. The measurement system must be able to record transient peaks and high frequencies accurately. The analysis technique must be able to characterise the impact signal in time and frequency. This paper presents a measurement system and analysis technique for the characterisation of large impacts. A piezo-electric accelerometer was securely mounted on the dorsal surface of the horses hoof. Saddle mounted charge amplifiers and a 20 m coaxial cable transferred these data to a PC based logging system. Data were down-loaded onto a UNIX workstation and analysed using a proprietary statistics package. The values of parameters calculated from the time series data were comparable to those of other authors. A wavelet decomposition showed that the frequency profile of the signal changed with time. While most spectral energy was seen at impact, a significant amount of energy was contained in the signal immediately following impact. Over 99% of this energy was contained in frequencies less than 1250 Hz. The sampling rate and the frequency response of a measurement system for recording impact should be chosen carefully to prevent loss or corruption of data. Time scale analysis using a wavelet decomposition is a powerful technique which can be used to characterise impact data. The use of contour plots provides a highly visual representation of the time and frequency localisation of power during impact.

Measurement of 15N longitudinal relaxation rates in 15NH4+ spin systems to characterise rotational correlation times and chemical exchange

NASA Astrophysics Data System (ADS)

Hansen, D. Flemming

2017-06-01

Many chemical and biological processes rely on the movement of monovalent cations and an understanding of such processes can therefore only be achieved by characterising the dynamics of the involved ions. It has recently been shown that 15N-ammonium can be used as a proxy for potassium to probe potassium binding in bio-molecules such as DNA quadruplexes and enzymes. Moreover, equations have been derived to describe the time-evolution of 15N-based spin density operator elements of 15NH4+ spin systems. Herein NMR pulse sequences are derived to select specific spin density matrix elements of the 15NH4+ spin system and to measure their longitudinal relaxation in order to characterise the rotational correlation time of the 15NH4+ ion as well as report on chemical exchange events of the 15NH4+ ion. Applications to 15NH4+ in acidic aqueous solutions are used to cross-validate the developed pulse sequence while measurements of spin-relaxation rates of 15NH4+ bound to a 41 kDa domain of the bacterial Hsp70 homologue DnaK are presented to show the general applicability of the derived pulse sequence. The rotational correlation time obtained for 15N-ammonium bound to DnaK is similar to the correlation time that describes the rotation about the threefold axis of a methyl group. The methodology presented here provides, together with the previous theoretical framework, an important step towards characterising the motional properties of cations in macromolecular systems.

High Speed Videometric Monitoring of Rock Breakage

NASA Astrophysics Data System (ADS)

Allemand, J.; Shortis, M. R.; Elmouttie, M. K.

2018-05-01

Estimation of rock breakage characteristics plays an important role in optimising various industrial and mining processes used for rock comminution. Although little research has been undertaken into 3D photogrammetric measurement of the progeny kinematics, there is promising potential to improve the efficacy of rock breakage characterisation. In this study, the observation of progeny kinematics was conducted using a high speed, stereo videometric system based on laboratory experiments with a drop weight impact testing system. By manually tracking individual progeny through the captured video sequences, observed progeny coordinates can be used to determine 3D trajectories and velocities, supporting the idea that high speed video can be used for rock breakage characterisation purposes. An analysis of the results showed that the high speed videometric system successfully observed progeny trajectories and showed clear projection of the progeny away from the impact location. Velocities of the progeny could also be determined based on the trajectories and the video frame rate. These results were obtained despite the limitations of the photogrammetric system and experiment processes observed in this study. Accordingly there is sufficient evidence to conclude that high speed videometric systems are capable of observing progeny kinematics from drop weight impact tests. With further optimisation of the systems and processes used, there is potential for improving the efficacy of rock breakage characterisation from measurements with high speed videometric systems.

Review of pore network modelling of porous media: Experimental characterisations, network constructions and applications to reactive transport.

PubMed

Xiong, Qingrong; Baychev, Todor G; Jivkov, Andrey P

2016-09-01

Pore network models have been applied widely for simulating a variety of different physical and chemical processes, including phase exchange, non-Newtonian displacement, non-Darcy flow, reactive transport and thermodynamically consistent oil layers. The realism of such modelling, i.e. the credibility of their predictions, depends to a large extent on the quality of the correspondence between the pore space of a given medium and the pore network constructed as its representation. The main experimental techniques for pore space characterisation, including direct imaging, mercury intrusion porosimetry and gas adsorption, are firstly summarised. A review of the main pore network construction techniques is then presented. Particular focus is given on how such constructions are adapted to the data from experimentally characterised pore systems. Current applications of pore network models are considered, with special emphasis on the effects of adsorption, dissolution and precipitation, as well as biomass growth, on transport coefficients. Pore network models are found to be a valuable tool for understanding and predicting meso-scale phenomena, linking single pore processes, where other techniques are more accurate, and the homogenised continuum porous media, used by engineering community. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Non-destructive geochemical analysis and element mapping using bench-top μ-XRF: applications and uses for geoscience problems

NASA Astrophysics Data System (ADS)

Flude, Stephanie; Haschke, Michael; Tagle, Roald; Storey, Michael

2013-04-01

X-Ray Fluorescence (XRF) has long been used to provide valuable geochemical analysis of bulk rock samples in geological studies. However, it is a destructive technique, requiring samples to be homogenised by grinding to a fine powder and formed into a compacted pellet, or fused glass disk and the resulting sample has to be completely flat for reliable analysis. Until recently, non-destructive, high spatial resolution µ- XRF analysis was possible only at specialised Synchrotron radiation facilities, where high excitation beam energies are possible and specialised X-ray focussing optical systems are available. Recently, a number of bench-top µ-XRF systems have become available, allowing easy, rapid and non-destructive geochemical analysis of various materials. We present a number of examples of how the new bench-top M4 Tornado µ-XRF system, developed by Bruker Nano, can be used to provide valuable geochemical information on geological samples. Both quantitative and qualitative (in the form of X-Ray area-maps) data can be quickly and easily acquired for a wide range of elements (as light as Na, using a vacuum), with minimal sample preparation, using an X-Ray spot size as low as 25 µm. Large specimens up to 30 cm and 5 kg in weight can be analysed due to the large sample chamber, allowing non-destructive characterisation of rare or valuable materials. This technique is particularly useful in characterising heterogeneous samples, such as drill cores, sedimentary and pyroclastic rocks containing a variety of clasts, lavas sourced from mixed and mingled magmas, mineralised samples and fossils. An obvious application is the ability to produce element maps or line-scans of minerals, allowing zoning of major and trace elements to be identified and thus informing on crystallisation histories. An application of particular interest to 40Ar/39Ar geochronologists is the ability to screen and assess the purity of mineral separates, or to characterise polished slabs for subsequent in-situ 40Ar/39Ar laser probe analysis; in the past such samples may have been characterised using SEM, but recent work [1] suggests that charging of a sample during electron-beam excitation can cause redistribution of K, thus disturb the 40Ar/39Ar system. Finally, we assess data accuracy and precision by presenting quantitative analyses of a number of standards. [1] Flude et al., The effect of SEM imaging on the Ar/Ar system in feldspars, V51C-2215 Poster, AGU Fall Meeting 2010

Kelvin-Voigt model of wave propagation in fragmented geomaterials with impact damping

NASA Astrophysics Data System (ADS)

Khudyakov, Maxim; Pasternak, Elena; Dyskin, Arcady

2017-04-01

When a wave propagates through real materials, energy dissipation occurs. The effect of loss of energy in homogeneous materials can be accounted for by using simple viscous models. However, a reliable model representing the effect in fragmented geomaterials has not been established yet. The main reason for that is a mechanism how vibrations are transmitted between the elements (fragments) in these materials. It is hypothesised that the fragments strike against each other, in the process of oscillation, and the impacts lead to the energy loss. We assume that the energy loss is well represented by the restitution coefficient. The principal element of this concept is the interaction of two adjacent blocks. We model it by a simple linear oscillator (a mass on an elastic spring) with an additional condition: each time the system travels through the neutral point, where the displacement is equal to zero, the velocity reduces by multiplying itself by the restitution coefficient, which characterises an impact of the fragments. This additional condition renders the system non-linear. We show that the behaviour of such a model averaged over times much larger than the system period can approximately be represented by a conventional linear oscillator with linear damping characterised by a damping coefficient expressible through the restitution coefficient. Based on this the wave propagation at times considerably greater than the resonance period of oscillations of the neighbouring blocks can be modelled using the Kelvin-Voigt model. The wave velocities and the dispersion relations are obtained.

Quantitative characterisation of audio data by ordinal symbolic dynamics

NASA Astrophysics Data System (ADS)

Aschenbrenner, T.; Monetti, R.; Amigó, J. M.; Bunk, W.

2013-06-01

Ordinal symbolic dynamics has developed into a valuable method to describe complex systems. Recently, using the concept of transcripts, the coupling behaviour of systems was assessed, combining the properties of the symmetric group with information theoretic ideas. In this contribution, methods from the field of ordinal symbolic dynamics are applied to the characterisation of audio data. Coupling complexity between frequency bands of solo violin music, as a fingerprint of the instrument, is used for classification purposes within a support vector machine scheme. Our results suggest that coupling complexity is able to capture essential characteristics, sufficient to distinguish among different violins.

Networked dynamical systems with linear coupling: synchronisation patterns, coherence and other behaviours.

PubMed

Judd, Kevin

2013-12-01

Many physical and biochemical systems are well modelled as a network of identical non-linear dynamical elements with linear coupling between them. An important question is how network structure affects chaotic dynamics, for example, by patterns of synchronisation and coherence. It is shown that small networks can be characterised precisely into patterns of exact synchronisation and large networks characterised by partial synchronisation at the local and global scale. Exact synchronisation modes are explained using tools of symmetry groups and invariance, and partial synchronisation is explained by finite-time shadowing of exact synchronisation modes.

Understanding the Factors that Characterise School-Community Partnerships: The Case of the Logan Healthy Schools Project

ERIC Educational Resources Information Center

Thomas, Melinda; Rowe, Fiona; Harris, Neil

2010-01-01

Purpose: The purpose of this study is to examine the factors that characterise effective school-community partnerships that support the sustainability of school health initiatives applied within a health-promoting schools approach. Design/methodology/approach: The study used an explanatory case study approach of five secondary schools…

Molecular and cellular characterisation of the zinc uptake (Znu) system of Nostoc punctiforme.

PubMed

Hudek, Lee; Pearson, Leanne A; Michalczyk, Agnes; Neilan, Brett A; Ackland, M Leigh

2013-11-01

Metal homoeostasis in cyanobacteria is based on uptake and export systems that are controlled by their own regulators. This study characterises the zinc uptake (Znu) system in Nostoc punctiforme. The system was found to comprise of three subunits in an ACB operon: a Zn(2+)-binding protein (ZnuA18), a transmembrane domain (ZnuB) and an ATPase (ZnuC). These proteins are encoded within the znu operon regulated by a zinc uptake transcription repressor (Zur). Interestingly, a second Zn(2+)-binding protein (ZnuA08) was also identified at a distal genomic location. Interactions between components of the ZnuACB system were investigated using knockouts of the individual genes. The znuA08(-), znuA18(-), znuB(-) and znuC(-) mutants displayed overall reduced znuACB transcript levels, suggesting that all system components are required for normal expression of znu genes. Zinc uptake assays in the Zn(2+)-binding protein mutant strains showed that the disruption of znuA18 had a greater negative effect on zinc uptake than disruption of znuA08. Complementation studies in Escherichia coli indicated that both znuA08 and znuA18 were able to restore zinc uptake in a znuA(-) mutant, with znuA18 permitting the highest zinc uptake rate. The N. punctiforme zur was also able to complement the E. coli zur(-) mutant. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Characterisation of nimesulide-betacyclodextrins systems prepared by supercritical fluid impregnation.

PubMed

Moneghini, M; Kikic, I; Perissutti, B; Franceschinis, E; Cortesi, A

2004-11-01

The purpose of this study was to apply the supercritical CO(2) impregnation process for preparing solvent-free nimesulide (NMS)-betacyclodextrins (BCD) association systems with enhanced drug dissolution rate. Several drug-to-carrier molar ratios were tested (1:1; 1:2.5; 1:3.5) at different conditions of temperatures (40, 100, and 130 degrees C) and pressures (140, 190 or 220 bar). The physical and morphological characterisation of the systems using powder X-ray diffraction, thermal analysis, diffuse reflectance Fourier transform-infrared spectroscopy and scanning electron microscopy was carried out to understand the influence of this technological process on the physical status of single components and binary systems and to detect possible interactions between drug and carrier. These analyses provided no evidence of a complete inclusion of NMS in the carrier but the existence of interactions between drug and carrier together with a partial dehydration of the BCD and the formation of drug crystallites with lower melting point and heat of fusion than the native NMS. These phenomena were more intense when severe conditions of pressure and temperature (220 bar and 130 degrees C) were used during impregnation trials and when the amount of BCD augmented in the systems. These activated solid state of the impregnated systems promoted an enhancement of drug dissolution rate that, in keeping with the results of the physical characterisation, was function of the process conditions and BCD content.

Characterisation methods for the hyperspectral sensor HySpex at DLR's calibration home base

NASA Astrophysics Data System (ADS)

Baumgartner, Andreas; Gege, Peter; Köhler, Claas; Lenhard, Karim; Schwarzmaier, Thomas

2012-09-01

The German Aerospace Center's (DLR) Remote Sensing Technology Institute (IMF) operates a laboratory for the characterisation of imaging spectrometers. Originally designed as Calibration Home Base (CHB) for the imaging spectrometer APEX, the laboratory can be used to characterise nearly every airborne hyperspectral system. Characterisation methods will be demonstrated exemplarily with HySpex, an airborne imaging spectrometer system from Norsk Elektro Optikks A/S (NEO). Consisting of two separate devices (VNIR-1600 and SWIR-320me) the setup covers the spectral range from 400 nm to 2500 nm. Both airborne sensors have been characterised at NEO. This includes measurement of spectral and spatial resolution and misregistration, polarisation sensitivity, signal to noise ratios and the radiometric response. The same parameters have been examined at the CHB and were used to validate the NEO measurements. Additionally, the line spread functions (LSF) in across and along track direction and the spectral response functions (SRF) for certain detector pixels were measured. The high degree of lab automation allows the determination of the SRFs and LSFs for a large amount of sampling points. Despite this, the measurement of these functions for every detector element would be too time-consuming as typical detectors have 105 elements. But with enough sampling points it is possible to interpolate the attributes of the remaining pixels. The knowledge of these properties for every detector element allows the quantification of spectral and spatial misregistration (smile and keystone) and a better calibration of airborne data. Further laboratory measurements are used to validate the models for the spectral and spatial properties of the imaging spectrometers. Compared to the future German spaceborne hyperspectral Imager EnMAP, the HySpex sensors have the same or higher spectral and spatial resolution. Therefore, airborne data will be used to prepare for and validate the spaceborne system's data.

Preparation, characterisation and critical flux determination of graphene oxide blended polysulfone (PSf) membranes in an MBR system.

PubMed

Ravishankar, Harish; Roddick, Felicity; Navaratna, Dimuth; Jegatheesan, Veeriah

2018-05-01

Microfiltration membranes having different blends of graphene-oxide (GO) (0-1 wt%) and Polysulfone (PSf) (15-20 wt%) were prepared using the classical non-solvent induced phase inversion process. The prepared membranes were characterised for their structural morphology, surface properties, mechanical strength, porosity and pure water flux. Based on the initial characterisation results, four membranes (15 wt% PSf, 15 wt% PSf + 0.25 wt% GO, 15 wt% PSf + 1 wt% GO and 20 wt% PSf + 1 wt% GO) were chosen for critical flux study, that was conducted using flux-step method in a lab scale MBR system. In order to study the application potential of GO blended membranes, the critical flux of each membrane was evaluated in two operational modes i.e., continuous and intermittent modes with backwash. The membranes with maximal GO concentration (15 wt% PSf + 1 wt% GO and 20 wt% PSf + 1 wt% GO) showed higher critical flux (16.5, 12.8 L/m 2 h and 19, 15 L/m 2 h for continuous and intermittent mode, respectively). It was observed that the operational modes did not have a significant effect on the critical flux of the membranes with low GO concentration (15 wt% PSf and 15 wt% PSf + 0.25 wt% GO), indicating a minimal of 1 wt% GO was required for an observable effect that favoured intermittent mode of operation. Through these results, ideal operating condition was arrived (i.e., flux maintained at 6.4 L/m 2 h operated under intermittent mode) and the membranes 15 wt% PSf and 15 wt% PSf + 1 wt% GO were studied for their long-term operation. The positive effect of GO on filtration time, cleaning frequency and against fouling was demonstrated through long term TMP profile of the membranes, indicating the suitability of GO blended membrane for real time wastewater treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Characterisation of a PEM Fuel-Cell System with a Focus on UAS Applications

DTIC Science & Technology

2014-01-01

consumption at rated output Approximately 580 ml/min (at normal conditions) Maximum permissible cell temperature Operation: 50 °C; starting: 45 °C...serves to control the temperature of the stack as well as to provide oxygen for the reaction. Fur- thermore, the theoretically computed airflow rate is...The stack temperature has a significant effect on the performance of a fuel cell. Therefore, an understanding of how a fuel cell functions across a

Thermodynamic properties of non-conformal soft-sphere fluids with effective hard-sphere diameters.

PubMed

Rodríguez-López, Tonalli; del Río, Fernando

2012-01-28

In this work we study a set of soft-sphere systems characterised by a well-defined variation of their softness. These systems represent an extension of the repulsive Lennard-Jones potential widely used in statistical mechanics of fluids. This type of soft spheres is of interest because they represent quite accurately the effective intermolecular repulsion in fluid substances and also because they exhibit interesting properties. The thermodynamics of the soft-sphere fluids is obtained via an effective hard-sphere diameter approach that leads to a compact and accurate equation of state. The virial coefficients of soft spheres are shown to follow quite simple relationships that are incorporated into the equation of state. The approach followed exhibits the rescaling of the density that produces a unique equation for all systems and temperatures. The scaling is carried through to the level of the structure of the fluids.

Geometrical Characterisation of a 2D Laser System and Calibration of a Cross-Grid Encoder by Means of a Self-Calibration Methodology

PubMed Central

Torralba, Marta; Díaz-Pérez, Lucía C.

2017-01-01

This article presents a self-calibration procedure and the experimental results for the geometrical characterisation of a 2D laser system operating along a large working range (50 mm × 50 mm) with submicrometre uncertainty. Its purpose is to correct the geometric errors of the 2D laser system setup generated when positioning the two laser heads and the plane mirrors used as reflectors. The non-calibrated artefact used in this procedure is a commercial grid encoder that is also a measuring instrument. Therefore, the self-calibration procedure also allows the determination of the geometrical errors of the grid encoder, including its squareness error. The precision of the proposed algorithm is tested using virtual data. Actual measurements are subsequently registered, and the algorithm is applied. Once the laser system is characterised, the error of the grid encoder is calculated along the working range, resulting in an expanded submicrometre calibration uncertainty (k = 2) for the X and Y axes. The results of the grid encoder calibration are comparable to the errors provided by the calibration certificate for its main central axes. It is, therefore, possible to confirm the suitability of the self-calibration methodology proposed in this article. PMID:28858239

Prevention, screening and treatment of colorectal cancer: a global and regional generalized cost effectiveness analysis

PubMed Central

2010-01-01

Background Regional generalized cost-effectiveness estimates of prevention, screening and treatment interventions for colorectal cancer are presented. Methods Standardised WHO-CHOICE methodology was used. A colorectal cancer model was employed to provide estimates of screening and treatment effectiveness. Intervention effectiveness was determined via a population state-transition model (PopMod) that simulates the evolution of a sub-regional population accounting for births, deaths and disease epidemiology. Economic costs of procedures and treatment were estimated, including programme overhead and training costs. Results In regions characterised by high income, low mortality and high existing treatment coverage, the addition of screening to the current high treatment levels is very cost-effective, although no particular intervention stands out in cost-effectiveness terms relative to the others. In regions characterised by low income, low mortality with existing treatment coverage around 50%, expanding treatment with or without screening is cost-effective or very cost-effective. Abandoning treatment in favour of screening (no treatment scenario) would not be cost effective. In regions characterised by low income, high mortality and low treatment levels, the most cost-effective intervention is expanding treatment. Conclusions From a cost-effectiveness standpoint, screening programmes should be expanded in developed regions and treatment programmes should be established for colorectal cancer in regions with low treatment coverage. PMID:20236531

Magnetic field effects on exciplex-forming systems: the effect on the locally excited fluorophore and its dependence on free energy.

PubMed

Kattnig, Daniel R; Rosspeintner, Arnulf; Grampp, Günter

2011-02-28

This study addresses magnetic field effects in exciplex forming donor-acceptor systems. For moderately exergonic systems, the exciplex and the locally excited fluorophore emission are found to be magneto-sensitive. A previously introduced model attributing this finding to excited state reversibility is confirmed. Systems characterised by a free energy of charge separation up to approximately -0.35 eV are found to exhibit a magnetic field effect on the fluorophore. A simple three-state model of the exciplex is introduced, which uses the reaction distance and the asymmetric electron transfer reaction coordinate as pertinent variables. Comparing the experimental emission band shapes with those predicted by the model, a semi-quantitative picture of the formation of the magnetic field effect is developed based on energy hypersurfaces. The model can also be applied to estimate the indirect contribution of the exchange interaction, even if the perturbative approach fails. The energetic parameters that are essential for the formation of large magnetic field effects on the exciplex are discussed.

Rapid characterisation of Klebsiella oxytoca isolates from contaminated liquid hand soap using mass spectrometry, FTIR and Raman spectroscopy.

PubMed

Dieckmann, Ralf; Hammerl, Jens Andre; Hahmann, Hartmut; Wicke, Amal; Kleta, Sylvia; Dabrowski, Piotr Wojciech; Nitsche, Andreas; Stämmler, Maren; Al Dahouk, Sascha; Lasch, Peter

2016-06-23

Microbiological monitoring of consumer products and the efficiency of early warning systems and outbreak investigations depend on the rapid identification and strain characterisation of pathogens posing risks to the health and safety of consumers. This study evaluates the potential of three rapid analytical techniques for identification and subtyping of bacterial isolates obtained from a liquid hand soap product, which has been recalled and reported through the EU RAPEX system due to its severe bacterial contamination. Ten isolates recovered from two bottles of the product were identified as Klebsiella oxytoca and subtyped using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI TOF MS), near-infrared Fourier transform (NIR FT) Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Comparison of the classification results obtained by these phenotype-based techniques with outcomes of the DNA-based methods pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis of whole-genome sequencing (WGS) data revealed a high level of concordance. In conclusion, a set of analytical techniques might be useful for rapid, reliable and cost-effective microbial typing to ensure safe consumer products and allow source tracking.

A new order-theoretic characterisation of the polytime computable functions☆

PubMed Central

Avanzini, Martin; Eguchi, Naohi; Moser, Georg

2015-01-01

We propose a new order-theoretic characterisation of the class of polytime computable functions. To this avail we define the small polynomial path order (sPOP⁎ for short). This termination order entails a new syntactic method to analyse the innermost runtime complexity of term rewrite systems fully automatically: for any rewrite system compatible with sPOP⁎ that employs recursion up to depth d, the (innermost) runtime complexity is polynomially bounded of degree d. This bound is tight. Thus we obtain a direct correspondence between a syntactic (and easily verifiable) condition of a program and the asymptotic worst-case complexity of the program. PMID:26412933

Characterization of highly efficient heavy-ion mutagenesis in Arabidopsis thaliana.

PubMed

Kazama, Yusuke; Hirano, Tomonari; Saito, Hiroyuki; Liu, Yang; Ohbu, Sumie; Hayashi, Yoriko; Abe, Tomoko

2011-11-15

Heavy-ion mutagenesis is recognised as a powerful technology to generate new mutants, especially in higher plants. Heavy-ion beams show high linear energy transfer (LET) and thus more effectively induce DNA double-strand breaks than other mutagenic techniques. Previously, we determined the most effective heavy-ion LET (LETmax: 30.0 keV μm(-1)) for Arabidopsis mutagenesis by analysing the effect of LET on mutation induction. However, the molecular structure of mutated DNA induced by heavy ions with LETmax remains unclear. Knowledge of the structure of mutated DNA will contribute to the effective exploitation of heavy-ion beam mutagenesis. Dry Arabidopsis thaliana seeds were irradiated with carbon (C) ions with LETmax at a dose of 400 Gy and with LET of 22.5 keV μm(-1) at doses of 250 Gy or 450 Gy. The effects on mutation frequency and alteration of DNA structure were compared. To characterise the structure of mutated DNA, we screened the well-characterised mutants elongated hypocotyls (hy) and glabrous (gl) and identified mutated DNA among the resulting mutants by high-resolution melting curve, PCR and sequencing analyses. The mutation frequency induced by C ions with LETmax was two-fold higher than that with 22.5 keV μm(-1) and similar to the mutation frequency previously induced by ethyl methane sulfonate. We identified the structure of 22 mutated DNAs. Over 80% of the mutations caused by C ions with both LETs were base substitutions or deletions/insertions of less than 100 bp. The other mutations involved large rearrangements. The C ions with LETmax showed high mutation efficiency and predominantly induced base substitutions or small deletions/insertions, most of which were null mutations. These small alterations can be determined by single-nucleotide polymorphism (SNP) detection systems. Therefore, C ions with LETmax might be useful as a highly efficient reverse genetic system in conjunction with SNP detection systems, and will be beneficial for forward genetics and plant breeding.

Characterisation of a hybrid, fuel-cell-based propulsion system for small unmanned aircraft

NASA Astrophysics Data System (ADS)

Verstraete, D.; Lehmkuehler, K.; Gong, A.; Harvey, J. R.; Brian, G.; Palmer, J. L.

2014-03-01

Advanced hybrid powerplants combining a fuel cell and battery can enable significantly higher endurance for small, electrically powered unmanned aircraft systems, compared with batteries alone. However, detailed investigations of the static and dynamic performance of such systems are required to address integration challenges. This article describes a series of tests used to characterise the Horizon Energy Systems' AeroStack hybrid, fuel-cell-based powertrain. The results demonstrate that a significant difference can exist between the dynamic performance of the fuel-cell system and its static polarisation curve, confirming the need for detailed measurements. The results also confirm that the AeroStack's lithium-polymer battery plays a crucial role in its response to dynamic load changes and protects the fuel cell from membrane dehydration and fuel starvation. At low static loads, the AeroStack fuel cell recharges the battery with currents up to 1 A, which leads to further differences with the polarisation curve.

Harmonised framework for ecological risk assessment of sediments from ports and estuarine zones of North and South Atlantic.

PubMed

Choueri, R B; Cesar, A; Abessa, D M S; Torres, R J; Riba, I; Pereira, C D S; Nascimento, M R L; Morais, R D; Mozeto, A A; DelValls, T A

2010-04-01

This paper presents a harmonised framework of sediment quality assessment and dredging material characterisation for estuaries and port zones of North and South Atlantic. This framework, based on the weight-of-evidence approach, provides a structure and a process for conducting sediment/dredging material assessment that leads to a decision. The main structure consists of "step 1" (examination of available data); "step 2" (chemical characterisation and toxicity assessment); "decision 1" (any chemical level higher than reference values? are sediments toxic?); "step 3" (assessment of benthic community structure); "step 4" (integration of the results); "decision 2" (are sediments toxic or benthic community impaired?); "step 5" (construction of the decision matrix) and "decision 3" (is there environmental risk?). The sequence of assessments may be interrupted when the information obtained is judged to be sufficient for a correct characterisation of the risk posed by the sediments/dredging material. This framework brought novel features compared to other sediment/dredging material risk assessment frameworks: data integration through multivariate analysis allows the identification of which samples are toxic and/or related to impaired benthic communities; it also discriminates the chemicals responsible for negative biological effects; and the framework dispenses the use of a reference area. We demonstrated the successful application of this framework in different port and estuarine zones of the North (Gulf of Cádiz) and South Atlantic (Santos and Paranaguá Estuarine Systems).

Hierarchical Markov blankets and adaptive active inference. Comment on "Answering Schrödinger's question: A free-energy formulation" by Maxwell James Désormeau Ramstead et al.

NASA Astrophysics Data System (ADS)

Kirchhoff, Michael

2018-03-01

Ramstead MJD, Badcock PB, Friston KJ. Answering Schrödinger's question: A free-energy formulation. Phys Life Rev 2018. https://doi.org/10.1016/j.plrev.2017.09.001 [this issue] motivate a multiscale characterisation of living systems in terms of hierarchically structured Markov blankets - a view of living systems as comprised of Markov blankets of Markov blankets [1-4]. It is effectively a treatment of what life is and how it is realised, cast in terms of how Markov blankets of living systems self-organise via active inference - a corollary of the free energy principle [5-7].

Structure-level fuel load assessment in the wildland-urban interface: a fusion of airborne laser scanning and spectral remote-sensing methodologies

Treesearch

Nicholas S. Skowronski; Scott Haag; Jim Trimble; Kenneth L. Clark; Michael R. Gallagher; Richard G. Lathrop

2015-01-01

Large-scale fuel assessments are useful for developing policy aimed at mitigating wildfires in the wildland-urban interface (WUI), while finer-scale characterisation is necessary for maximising the effectiveness of fuel reduction treatments and directing suppression activities. We developed and tested an objective, consistent approach for characterising hazardous fuels...

Characterisation of bare and tannase-loaded calcium alginate beads by microscopic, thermogravimetric, FTIR and XRD analyses.

PubMed

Larosa, Claudio; Salerno, Marco; de Lima, Juliana Silva; Merijs Meri, Remo; da Silva, Milena Fernandes; de Carvalho, Luiz Bezerra; Converti, Attilio

2018-08-01

Incorporating enzymes into calcium alginate beads is an effective method to immobilise them and to preserve, at the same time, their catalytic activity. Sodium alginate was mixed with Aspergillus ficuum tannase in aqueous solution, and tannase-loaded calcium alginate beads were prepared using a simple droplet-based microfluidic system. Extensive experimental analysis was carried out to characterise the samples. Microscopic imaging revealed morphological differences between the surfaces of bare alginate matrix and tannase-loaded alginate beads. Thermal analysis allowed assessing the hydration contents of alginate and revealed the presence of tannase entrapped in the loaded beads, which was confirmed by vibrational spectroscopy. X-ray diffraction allowed us to conclude that alginate of tannase-loaded beads is not crystalline, which would make them suitable as carriers for possible controlled release. Moreover, they could be used in food applications to improve tea quality or clarify juices. Copyright © 2018 Elsevier B.V. All rights reserved.

Development and characterisation of polymeric microparticle of poly(d,l-lactic acid) loaded with holmium acetylacetonate.

PubMed

de Azevedo, Mariangela de Burgos M; de Melo, Vitor H S; Soares, Carlos Roberto J; Miyamoto, Douglas M; Katayama, Ricardo A; Squair, Peterson L; Barros, Caio H N; Tasic, Ljubica

2018-06-14

Biodegradable polymers containing radioactive isotopes such as Holmium 166 ( 166 Ho) have potential applications as beta particle emitters in tumour tissues. It is also a gamma ray emitter, allowing nuclear imaging of any tissue to be acquired. It is frequently used in the form of complexes such as holmium acetylacetonate (HoAcAc), which may cause damages in tissues next to the targets cancer cells, as it is difficult to control its linkage or healthy tissues radiotherapy effects. Poly(d,l-lactic acid), PDLLA, was used to encapsulate holmium acetylacetonate (HoAcAc) using an emulsion solvent extraction/evaporation technique. Microspheres with sizes between 20-53 µm were extensively characterised. HoAcAc release from the microspheres was assessed through studies using Inductively Coupled Plasma - Optical Emission Spectroscopy, and the microspheres showed no holmium leakage after a period of 10 half-lives and following gamma irradiation. Thus, HoAcAc loaded microspheres are here presented as a potential system for brachytherapy and imaging purposes.

Methamphetamine abuse and “meth mouth” in Europe

PubMed Central

Boyd, Geraldine-A.; Mancinelli, Luca; Pagano, Stefano; Eramo, Stefano

2015-01-01

With easy chemical synthesis from its precursor, methamphetamine (MA) is now widespread in many countries. The abuse of methamphetamine is associated with several negative effects on health, because MA is a neurotoxin and a dangerous central nervous system stimulant. It changes levels of neurotransmitters in the brain, releasing dopamine and inhibiting nor epinephrine uptake which increases sympathetic nervous system activity and can lead to cardiac arrhythmia, hypertension and tachypnea. The consequences of MA abuse are clearly manifested in oral diseases (like “meth mouth”) which is characterised by extensive caries, teeth grinding with ensuing dental wear and trismus. The present review was designed to fill the gap in knowledge about methamphetamine abuse in the European Union (EU) and to illustrate the main clinical effects of prolonged use. After describing the pharmacology and systemic effects of methamphetamine and concentrating on its effects on the mouth, the present review compares the epidemiology and incidence of abuse in the world, particularly the USA and the EU. Key words:Methamphetamine, “Meth mouth”, drug abuse, oral health. PMID:25662544

Optical characterisation and analysis of multi-mode pixels for use in future far infrared telescopes

NASA Astrophysics Data System (ADS)

McCarthy, Darragh; Trappe, Neil; Murphy, J. Anthony; Doherty, Stephen; Gradziel, Marcin; O'Sullivan, Créidhe; Audley, Michael D.; de Lange, Gert; van der Vorst, Maarten

2016-07-01

In this paper we present the development and verification of feed horn simulation code based on the mode- matching technique to simulate the electromagnetic performance of waveguide based structures of rectangular cross-section. This code is required to model multi-mode pyramidal horns which may be required for future far infrared (far IR) space missions where wavelengths in the range of 30 to 200 µm will be analysed. Multi-mode pyramidal horns can be used effectively to couple radiation to sensitive superconducting devices like Kinetic Inductance Detectors (KIDs) or Transition Edge Sensor (TES) detectors. These detectors could be placed in integrating cavities (to further increase the efficiency) with an absorbing layer used to couple to the radiation. The developed code is capable of modelling each of these elements, and so will allow full optical characterisation of such pixels and allow an optical efficiency to be calculated effectively. As the signals being measured at these short wavelengths are at an extremely low level, the throughput of the system must be maximised and so multi-mode systems are proposed. To this end, the focal planes of future far IR missions may consist of an array of multi-mode rectangular feed horns feeding an array of, for example, TES devices contained in individual integrating cavities. Such TES arrays have been fabricated by SRON Groningen and are currently undergoing comprehensive optical, electrical and thermal verification. In order to fully understand and validate the optical performance of the receiver system, it is necessary to develop comprehensive and robust optical models in parallel. We outline the development and verification of this optical modelling software by means of applying it to a representative multi-mode system operating at 150 GHz in order to obtain sufficiently short execution times so as to comprehensively test the code. SAFARI (SPICA FAR infrared Instrument) is a far infrared imaging grating spectrometer, to be proposed as an ESA M5 mission. It is planned for this mission to be launched on board the proposed SPICA (SPace Infrared telescope for Cosmology and Astrophysics) mission, in collaboration with JAXA. SAFARI is planned to operate in the 1.5-10 THz band, focussing on the formation and evolution of galaxies, stars and planetary systems. The pixel that drove the development of the techniques presented in this paper is typical of one option that could be implemented in the SAFARI focal plane, and so the ability to accurately understand and characterise such pixels is critical in the design phase of the next generation of far IR telescopes.

[Legitimizing and responsibilities of public health reports: public health reports or social court reports?].

PubMed

Borgers, D; Streich, W

1996-11-01

Since 1970 various initiatives have been taken to improve the information bases of health reporting. However, the efforts made up to now by the Länder, the Federal Government and its corporate bodies are characterised by a lack of experience and shortage of resources; moreover, they are viewed with a critical eye by the public and in the political area. In this contribution the authors describe various topics and delimitations of a health reporting system which go far beyond health statistics and health programmes altogether. The chances of a national health reporting system are based on the assumption that an objective judgement based on expert knowledge and science will be possible and that beyond all particularistic interests, expert knowledge can be organised in a democratic process. Public health reporting varies between two extremes: On the one hand, the current reporting in the media on health-related subjects which is characterised by disagreement among experts, particularistic interests and emotions, and on the other hand the national health reporting, which, on the platform of policy marketing and political image shaping, is suspected of degenerating to a kind of "royal court reporting". A health reporting system based on expert knowledge and characterised by topics with relevance to health policy, expert quality of its information and neutrality to particularistic interests, should go beyond these two extremes. Given the political conditions of budgeting and distribution conflicts, health reporting has to deal with two main aspects: effectiveness and efficiency of employed resources and with the problems of a fair distribution of these resources to provide equal chances in the health sector. What cannot be solved, by questions of procedure, however, is the problem of truth and objective knowledge as well as the problem of confidence. If the general public lacks confidence in national expert knowledge, a society discourse will not lead to political results. Additionally, the argument that medicine is of little importance for health is used to categorically reject a rational investigation of needs and thus to reduce the health system to the status of a modern religious doctrine. Proceeding on the assumption that due to systematic thinking and acting in the field of science, effective medicine symbolises one of the paradigms of progress, then health reporting system can be justified despite the precarious objective knowledge, provided such reporting generates the confidence it deserves thanks to its quality standards and seriousness.

Evaluation of a Screening System for Obesogenic Compounds: Screening of Endocrine Disrupting Compounds and Evaluation of the PPAR Dependency of the Effect

PubMed Central

Pereira-Fernandes, Anna; Demaegdt, Heidi; Vandermeiren, Karine; Hectors, Tine L. M.; Jorens, Philippe G.; Blust, Ronny; Vanparys, Caroline

2013-01-01

Recently the environmental obesogen hypothesis has been formulated, proposing a role for endocrine disrupting compounds (EDCs) in the development of obesity. To evaluate this hypothesis, a screening system for obesogenic compounds is urgently needed. In this study, we suggest a standardised protocol for obesogen screening based on the 3T3-L1 cell line, a well-characterised adipogenesis model, and direct fluorescent measurement using Nile red lipid staining technique. In a first phase, we characterised the assay using the acknowledged obesogens rosiglitazone and tributyltin. Based on the obtained dose-response curves for these model compounds, a lipid accumulation threshold value was calculated to ensure the biological relevance and reliability of statistically significant effects. This threshold based method was combined with the well described strictly standardized mean difference (SSMD) method for classification of non-, weak- or strong obesogenic compounds. In the next step, a range of EDCs, used in personal and household care products (parabens, musks, phthalates and alkylphenol compounds), were tested to further evaluate the obesogenicity screening assay for its discriminative power and sensitivity. Additionally, the peroxisome proliferator activated receptor γ (PPARγ) dependency of the positive compounds was evaluated using PPARγ activation and antagonist experiments. Our results showed the adipogenic potential of all tested parabens, several musks and phthalate compounds and bisphenol A (BPA). PPARγ activation was associated with adipogenesis for parabens, phthalates and BPA, however not required for obesogenic effects induced by Tonalide, indicating the role of other obesogenic mechanisms for this compound. PMID:24155963

Evaluation of illumination system uniformity for wide-field biomedical hyperspectral imaging

NASA Astrophysics Data System (ADS)

Sawyer, Travis W.; Siri Luthman, A.; E Bohndiek, Sarah

2017-04-01

Hyperspectral imaging (HSI) systems collect both spatial (morphological) and spectral (chemical) information from a sample. HSI can provide sensitive analysis for biological and medical applications, for example, simultaneously measuring reflectance and fluorescence properties of a tissue, which together with structural information could improve early cancer detection and tumour characterisation. Illumination uniformity is a critical pre-condition for quantitative data extraction from an HSI system. Non-uniformity can cause glare, specular reflection and unwanted shading, which negatively impact statistical analysis procedures used to extract abundance of different chemical species. Here, we model and evaluate several illumination systems frequently used in wide-field biomedical imaging to test their potential for HSI. We use the software LightTools and FRED. The analysed systems include: a fibre ring light; a light emitting diode (LED) ring; and a diffuse scattering dome. Each system is characterised for spectral, spatial, and angular uniformity, as well as transfer efficiency. Furthermore, an approach to measure uniformity using the Kullback-Leibler divergence (KLD) is introduced. The KLD is generalisable to arbitrary illumination shapes, making it an attractive approach for characterising illumination distributions. Although the systems are quite comparable in their spatial and spectral uniformity, the most uniform angular distribution is achieved using a diffuse scattering dome, yielding a contrast of 0.503 and average deviation of 0.303 over a ±60° field of view with a 3.9% model error in the angular domain. Our results suggest that conventional illumination sources can be applied in HSI, but in the case of low light levels, bespoke illumination sources may offer improved performance.

Bayesian models for cost-effectiveness analysis in the presence of structural zero costs

PubMed Central

Baio, Gianluca

2014-01-01

Bayesian modelling for cost-effectiveness data has received much attention in both the health economics and the statistical literature, in recent years. Cost-effectiveness data are characterised by a relatively complex structure of relationships linking a suitable measure of clinical benefit (e.g. quality-adjusted life years) and the associated costs. Simplifying assumptions, such as (bivariate) normality of the underlying distributions, are usually not granted, particularly for the cost variable, which is characterised by markedly skewed distributions. In addition, individual-level data sets are often characterised by the presence of structural zeros in the cost variable. Hurdle models can be used to account for the presence of excess zeros in a distribution and have been applied in the context of cost data. We extend their application to cost-effectiveness data, defining a full Bayesian specification, which consists of a model for the individual probability of null costs, a marginal model for the costs and a conditional model for the measure of effectiveness (given the observed costs). We presented the model using a working example to describe its main features. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd. PMID:24343868

Bayesian models for cost-effectiveness analysis in the presence of structural zero costs.

PubMed

Baio, Gianluca

2014-05-20

Bayesian modelling for cost-effectiveness data has received much attention in both the health economics and the statistical literature, in recent years. Cost-effectiveness data are characterised by a relatively complex structure of relationships linking a suitable measure of clinical benefit (e.g. quality-adjusted life years) and the associated costs. Simplifying assumptions, such as (bivariate) normality of the underlying distributions, are usually not granted, particularly for the cost variable, which is characterised by markedly skewed distributions. In addition, individual-level data sets are often characterised by the presence of structural zeros in the cost variable. Hurdle models can be used to account for the presence of excess zeros in a distribution and have been applied in the context of cost data. We extend their application to cost-effectiveness data, defining a full Bayesian specification, which consists of a model for the individual probability of null costs, a marginal model for the costs and a conditional model for the measure of effectiveness (given the observed costs). We presented the model using a working example to describe its main features. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

Laser ultrasonic characterization of membranes for use as micro-electronic mechanical systems (MEMS)

NASA Astrophysics Data System (ADS)

Edwards, R. S.; Zhou, L. Q.; Pearce, M. J.; Prince, R. G.; Colston, G.; Myronov, M.; Leadley, D. R.; Trushkevych, O.

2017-02-01

Germanium (Ge) on Silicon (Si) has the potential to produce a wide variety of devices, including sensors, solar cells and transistors. Modification of these materials so that a suspended membrane layer is formed, through removing regions of the Si substrate, offers the potential for sensors with a more rapid response and higher sensitivity. Such membranes are a very simple micro-electronic mechanical system (MEMS). It is essential to ensure that the membranes are robust against shock and vibration, with well-characterised resonant frequencies, prior to any practical application. We present work using laser interferometry to characterise the resonant modes of membranes produced from Ge or silicon carbide (SiC) on a Si substrate, with the membranes typically having around 1 mm lateral dimensions. Two dimensional scanning of the sample enables visualisation of each mode. The stress measured from the resonant frequencies agrees well with that calculated from the growth conditions. SiC provides a more robust platform for electronics, while Ge offers better resonant properties. This offers a potential technique for characterising production quality or lifetime testing for the MEMS produced.

Characterisation and identification of bacteria using SERS.

PubMed

Jarvis, Roger M; Goodacre, Royston

2008-05-01

Within microbiology Raman spectroscopy is considered as a very important whole-organism fingerprinting technique, which is used to characterise, discriminate and identify microorganisms and assess how they respond to abiotic or biotic stress. Enhancing the sensitivity of Raman spectroscopy is very beneficial for the rapid analysis of bacteria (and indeed biological systems in general), where the ultimate goal is to achieve this without the need for lengthy cell culture. Bypassing this step would provide significant benefits in many areas such as medical, environmental and industrial microbiology, microbial systems biology, biological warfare countermeasures and bioprocess monitoring. In this tutorial review we will report on the advances made in bacterial studies, a relatively new and exciting application area for SERS.

Active matter and Curvature

NASA Astrophysics Data System (ADS)

Sknepnek, Rastko

Coupling between active motion and curvature is an integral part of many fundamental biological processes such as gastrulation and intestinal crypt fission. However, to date very little is known about how curvature affects active motion. Here we use a particle-based model to study the interplay between activity and curvature in dense systems. Using detailed numerical simulations and simple physical arguments, we show that the presence of curvature results in a number of steady-state configurations that have no analogues in flat geometries. These states are particularly interesting if topological constraints require the presence of defects in the ground states in the passive limit. We focus on polar and nematic active systems confined to move on the surface of a sphere and show that activity can lead to the formation of moving band and multidefect states. We extend our model to self-propelled filaments confined to a plane or the surface of a sphere. We show that the activity leads to an effective softening of the polymer chain. As a result of this softening, with the increase in activity, the system transitions between a jammed polymer-melt state, an active turbulent state characterised by a proliferation of hair-pin defects, to a region dominated by phase segregation (MIPS), finally followed by the onset of a homogenous state characterised by spiral motion of individual polymers. UK EPSRC EP/M009599/1.

Stress polishing demonstrator for ELT M1 segments and industrialization

NASA Astrophysics Data System (ADS)

Hugot, Emmanuel; Bernard, Anaïs.; Laslandes, Marie; Floriot, Johan; Dufour, Thibaut; Fappani, Denis; Combes, Jean Marc; Ferrari, Marc

2014-07-01

After two years of research and development under ESO support, LAM and Thales SESO present the results of their experiment for the fast and accurate polishing under stress of ELT 1.5 meter segments as well as the industrialization approach for mass production. Based on stress polishing, this manufacturing method requires the conception of a warping harness able to generate extremely accurate bending of the optical surface of the segments during the polishing. The conception of the warping harness is based on finite element analysis and allowed a fine tuning of each geometrical parameter of the system in order to fit an error budget of 25nm RMS over 300μm of bending peak to valley. The optimisation approach uses the simulated influence functions to extract the system eigenmodes and characterise the performance. The same approach is used for the full characterisation of the system itself. The warping harness has been manufactured, integrated and assembled with the Zerodur 1.5 meter segment on the LAM 2.5meter POLARIS polishing facility. The experiment consists in a cross check of optical and mechanical measurements of the mirrors bending in order to develop a blind process, ie to bypass the optical measurement during the final industrial process. This article describes the optical and mechanical measurements, the influence functions and eigenmodes of the system and the full performance characterisation of the warping harness.

Large-scale deployment of the Global Trigger Tool across a large hospital system: refinements for the characterisation of adverse events to support patient safety learning opportunities.

PubMed

Good, V S; Saldaña, M; Gilder, R; Nicewander, D; Kennerly, D A

2011-01-01

The Institute for Healthcare Improvement encourages use of the Global Trigger Tool to objectively determine and monitor adverse events (AEs). Baylor Health Care System (BHCS) is an integrated healthcare delivery system in North Texas. The Global Trigger Tool was applied to BHCS's eight general acute care hospitals, two inpatient cardiovascular hospitals and two rehabilitation/long-term acute care hospitals. Data were collected from a monthly random sample of charts for each facility for patients discharged between 1 July 2006 and 30 June 2007 by external professional nurse auditors using an MS Access Tool developed for this initiative. In addition to the data elements recommended by Institute for Healthcare Improvement, BHCS developed fields to permit further characterisation of AEs to identify learning opportunities. A structured narrative description of each identified AE facilitated text mining to further characterise AEs. INITIAL FINDINGS: Based on this sample, AE rates were found to be 68.1 per 1000 patient days, or 50.8 per 100 encounters, and 39.8% of admissions were found to have ≥1 AE. Of all AEs identified, 61.2% were hospital-acquired, 10.1% of which were associated with a National Coordinating Council - Medical Error Reporting and Prevention harm score of "H or I" (near death or death). To enhance learning opportunities and guide quality improvement, BHCS collected data-such as preventability and AE source-to characterise the nature of AEs. Data are provided regularly to hospital teams to direct quality initiatives, moving from a general focus on reducing AEs to more specific programmes based on patterns of harm and preventability.

Equity - some theory and its policy implications

PubMed Central

Culyer, A.

2001-01-01

This essay seeks to characterise the essential features of an equitable health care system in terms of the classical Aristotelian concepts of horizontal and vertical equity, the common (but ill-defined) language of "need" and the economic notion of cost-effectiveness as a prelude to identifying some of the more important issues of value that policy-makers will have to decide for themselves; the characteristics of health (and what determines it) that can cause policy to be ineffective (or have undesired consequences); the information base that is required to support a policy directed at securing greater equity, and the kinds of research (theoretical and empirical) that are needed to underpin such a policy. Key Words: Health care systems • equity • horizontal equity • vertical equity • cost-effectiveness PMID:11479360

Health Behaviour Change Through Computer Games: Characterising Interventions.

PubMed

Poultney, Nathan; Maeder, Anthony; Ginige, Jeewani Anupama

2016-01-01

Recently games in the form of video, computer, or mobile apps have been utilised as an effective component of interventions for health behaviour change. This paper provides an overview of related projects reported in peer-review literature in the period 2006 to 2016. Nine highly relevant references were considered for analysis. The findings are presented according to 3 dimensions of characterisation: health intention, behaviour change principle, and health purpose.

Effects of different excitation waveforms on detection and characterisation of delamination in PV modules by active infrared thermography

NASA Astrophysics Data System (ADS)

Sinha, Archana; Gupta, Rajesh

2017-10-01

Delamination significantly affects the performance and reliability of photovoltaic (PV) modules. Recently, an active infrared thermography approach using step heating has been exploited for the detection and characterisation of delamination in PV modules. However, step heating takes longer observation time and causes overheating problems. This paper presents the effects of different thermal excitation waveforms namely rectangular, half-sine and short pulse, on the detection and characterisation of delamination in PV module by experiments and simulations. For simulation, a 3-dimensional electro-thermal model of heat conduction, based on resistance-capacitance network approach, has been exploited to study the variation in maximum thermal contrast and peak contrast time with the delamination thickness and heating parameters. Results show that the rectangular waveform provides better detection of delamination due to higher absolute contrast, while the half-sine waveform allows better characterisation of delamination in the PV modules with low-cost and low-power heat source. The high-energy short pulse enabled quick visualisation of delamination, but has limited practical implementation. The advantages and limitations of each waveform have been highlighted to assess the specific requirement for appropriate choice in the non-destructive thermographic inspection of delamination in PV modules at the manufacturing units or outdoor fields.

Microfluidic free-flow electrophoresis for the discovery and characterisation of calmodulin binding partners

NASA Astrophysics Data System (ADS)

Herling, Therese; Linse, Sara; Knowles, Tuomas

2015-03-01

Non-covalent and transient protein-ligand interactions are integral to cellular function and malfunction. Key steps in signalling and regulatory pathways rely on reversible non-covalent protein-protein binding or ion chelation. Here we present a microfluidic free-flow electrophoresis method for detecting and characterising protein-ligand interactions in solution. We apply this method to probe the binding equilibria of calmodulin, a central protein to calcium signalling pathways. In this study we characterise the specific binding of calmodulin to phosphorylase kinase, a known target, and creatine kinase, which we identify as a putative binding partner through a protein array screen and surface plasmon resonance experiments. We verify the interaction between calmodulin and creatine kinase in solution using free-flow electrophoresis and investigate the effect of calcium and sodium chloride on the calmodulin-ligand binding affinity in free solution without the presence of a potentially interfering surface. Our results demonstrate the general applicability of quantitative microfluidic electrophoresis to characterise binding equilibria between biomolecules in solution.

One year in review 2017: systemic sclerosis.

PubMed

Barsotti, Simone; Bruni, Cosimo; Orlandi, Martina; Della Rossa, Alessandra; Marasco, Emiliano; Codullo, Veronica; Guiducci, Serena

2017-01-01

Systemic sclerosis is a rare acquired systemic disease characterised by heterogeneous evolution and outcome. Each year novel insights into the pathogenesis, diagnosis and treatment of this severe disease have been published. We herewith provide our overview of the most significant literature contributions published over the last year.

Biofilm responses to ageing and to a high phosphate load in a bench-scale drinking water system.

PubMed

Batté, Magali; Koudjonou, Boniface; Laurent, Patrick; Mathieu, Laurence; Coallier, Josée; Prévost, Michèle

2003-03-01

The effects of ageing and of phosphate load on drinking water biofilms developed on a polycarbonate substratum in the pseudo-equilibrium state have been evaluated. Phosphate was added in an amount higher than the stochiometric nutrient requirements of bacteria, at concentrations commonly applied in a drinking water distribution system for corrosion control. Multiple parameters were monitored: heterotrophic plate counts (HPCs), total direct counts (TDCs) and potential exoproteolytic activity (PEPA) in order to characterise changes in bacterial biofilms. The total carbohydrate, amino acid and phosphate contents of biofilms were analysed to characterise and monitor the biochemical composition of the biofilm.The three enumeration methods showed that a pseudo-equilibrium state was reached after 7 weeks of colonisation after which, the bacterial growth rate in the biofilm was 0.1 log per week on average. Bulk phosphate addition doubled the phosphate in the biofilm, but did not affect the other biological, physiological or chemical parameters measured. Polysaccharides increased in the biofilm with ageing and the dynamics of individual carbohydrate synthesis also varied with the age of the biofilm. Once pseudo-equilibrium, it was found that the total proteins were globally constant, whereas the spectra of some individual amino acids of the proteins had significantly changed.

Characterisation of metals in the electronic waste of complex mixtures of end-of-life ICT products for development of cleaner recovery technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Z.H.I.; Xiao, Y.; Sietsma, J.

2015-01-15

Highlights: • New characterisation methodology has been established to understand an industrially processed ICT waste. • Particle size distribution, composition, thermal–chemical behaviour and occurrence of metals were considered. • The characterisation provides direct guidelines for values recovery from the waste. - Abstract: Recycling of valuable metals from electronic waste, especially complex mixtures of end-of-life information and communication technology (ICT) products, is of great difficulty due to their complexity and heterogeneity. One of the important reasons is the lack of comprehensive characterisation on such materials, i.e. accurate compositions, physical/chemical properties. In the present research, we focus on developing methodologies for themore » characterisation of metals in an industrially processed ICT waste. The morphology, particle size distribution, compositional distribution, occurrence, liberation as well as the thermo-chemical properties of the ICT waste were investigated with various characterisation techniques, including X-ray Fluorescence Spectrometry (XRF), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) with energy dispersed spectroscopy (EDS). Due to the high heterogeneity of the material, special sample preparation procedures were introduced to minimise the discrepancies during compositional analyses. As a result, a clearer overview of the ICT waste has been reached. This research provides better understanding of the extractability of each metal and improves the awareness of potential obstacles for extraction. It will lead to smarter decisions during further development of a clean and effective recovery process.« less

Improving influenza virological surveillance in Europe: strain-based reporting of antigenic and genetic characterisation data, 11 European countries, influenza season 2013/14

PubMed Central

Broberg, Eeva; Hungnes, Olav; Schweiger, Brunhilde; Prosenc, Katarina; Daniels, Rod; Guiomar, Raquel; Ikonen, Niina; Kossyvakis, Athanasios; Pozo, Francisco; Puzelli, Simona; Thomas, Isabelle; Waters, Allison; Wiman, Åsa; Meijer, Adam

2016-01-01

Influenza antigenic and genetic characterisation data are crucial for influenza vaccine composition decision making. Previously, aggregate data were reported to the European Centre for Disease Prevention and Control by European Union/European Economic Area (EU/EEA) countries. A system for collecting case-specific influenza antigenic and genetic characterisation data was established for the 2013/14 influenza season. In a pilot study, 11 EU/EEA countries reported through the new mechanism. We demonstrated feasibility of reporting strain-based antigenic and genetic data and ca 10% of influenza virus-positive specimens were selected for further characterisation. Proportions of characterised virus (sub)types were similar to influenza virus circulation levels. The main genetic clades were represented by A/StPetersburg/27/2011(H1N1)pdm09 and A/Texas/50/2012(H3N2). A(H1N1)pdm09 viruses were more prevalent in age groups (by years) < 1 (65%; p = 0.0111), 20–39 (50%; p = 0.0046) and 40–64 (55%; p = 0.00001) while A(H3N2) viruses were most prevalent in those ≥ 65 years (62%*; p = 0.0012). Hospitalised patients in the age groups 6–19 years (67%; p = 0.0494) and ≥ 65 years (52%; p = 0.0005) were more frequently infected by A/Texas/50/2012 A(H3N2)-like viruses compared with hospitalised cases in other age groups. Strain-based reporting enabled deeper understanding of influenza virus circulation among hospitalised patients and substantially improved the reporting of virus characterisation data. Therefore, strain-based reporting of readily available data is recommended to all reporting countries within the EU/EEA. PMID:27762211

Fabrication and characterisation of nanocrystalline graphite MEMS resonators using a geometric design to control buckling

NASA Astrophysics Data System (ADS)

Fishlock, S. J.; O'Shea, S. J.; McBride, J. W.; Chong, H. M. H.; Pu, S. H.

2017-09-01

The simulation, fabrication and characterisation of nanographite MEMS resonators is reported in this paper. The deposition of nanographite is achieved using plasma-enhanced chemical vapour deposition directly onto numerous substrates such as commercial silicon wafers. As a result, many of the reliability issues of devices based on transferred graphene are avoided. The fabrication of the resonators is presented along with a simple undercutting method to overcome buckling, by changing the effective stress of the structure from ~436 MPa compressive, to ~13 MPa tensile. The characterisation of the resonators using electrostatic actuation and laser Doppler vibrometry is reported, demonstrating resonator frequencies from 5-640 kHz and quality factor above 1819 in vacuum obtained.

Characterisation of the aqueous corrosion process in NdFeB melt spun ribbon and MQI bonded magnets

NASA Astrophysics Data System (ADS)

McCain, Stephen

A major factor limiting the use and longevity of rare earth based magnetic materials is their susceptibility to aqueous corrosion and associated detrimental effects upon the magnetic properties of the material. This process was investigated through a combination of exposure to simulated environmental conditions and hydrogen absorption/desorption studies (HADS) in conjunction with magnetic characterisation. This study utilises NdFeB MQP-B melt-spun ribbon manufactured by Magnequench, in the form of MQI bonded magnets and also in its unbonded state as MQ powder. Specifically, it was concerned with how effective a variety of bonding media (epoxy resin,PTFE, zinc) and surface coatings (PTFE, Qsil, zinc LPPS, Dex-Cool) were at limiting the impact of aqueous corrosion in MQI bonded magnets. To characterise the effect of hydrogen absorption upon the magnetic properties of the MQP-B, hydrogen uptake was induced followed by a series of outgassing heat treatments with subsequent magnetic characterisation accompanied by HADS techniques performed after each outgas. This allowed comparisons to be made between the effects of aqueous corrosion process and hydrogen absorption upon the magnetic properties of the alloy.. This study has clearly demonstrated the link between the abundance of environmental moisture and rate of Hci losses in MQI bonded magnets. In addition to this the key mechanism responsible for the degradation of magnetic properties has been identified. These losses have been attributed to the absorption of hydrogen generated by the dissociation of water in the presence of NdFeB during the aqueous corrosion process. It has been shown that the use of a bonding media that is impermeable to water can limit the effects of aqueous corrosion by limiting water access to the Magnequench particles (MQP) and also the positive effects of the use of suitable surface coatings has been shown to be effective for the same reason..

Temperatures during flower bud development affect pollen germination, self-incompatibility reaction and early fruit development of clementine (Citrus clementina Hort. ex Tan.).

PubMed

Distefano, G; Gentile, A; Hedhly, A; La Malfa, S

2018-03-01

One of the key environmental factors affecting plant reproductive systems is temperature. Characterising such effects is especially relevant for some commercially important genera such as Citrus. In this genus, failure of fertilisation results in parthenocarpic fruit development and seedlessness, which is a much-prized character. Here, we characterise the effects of temperature on flower and ovary development, and on pollen-pistil interactions in 'Comune' clementine (Citrus clementina Hort. ex Tan.). We examine flower bud development, in vitro pollen germination and pollen-pistil interaction at different temperatures (15, 20, 25 or 30 °C). These temperatures span the range from 'cold' to 'hot' weather during the flowering season in many citrus-growing regions. Temperature had a strong effect on flower and ovary development, pollen germination, and pollen tube growth kinetics. In particular, parthenocarpic fruit development (indicated by juice vesicle growth) was initiated early if flowers were exposed to warmer temperatures during anthesis. Exposure to different temperatures during flower bud development also alters expression of the self-incompatibility reaction. This affects the point in the pistil at which pollen tube growth is arrested and confirms the role of sub- and supra-optimal temperatures in determining the numbers of pollen tubes reaching the ovary. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

Characterisation of residual ionospheric errors in bending angles using GNSS RO end-to-end simulations

NASA Astrophysics Data System (ADS)

Liu, C. L.; Kirchengast, G.; Zhang, K. F.; Norman, R.; Li, Y.; Zhang, S. C.; Carter, B.; Fritzer, J.; Schwaerz, M.; Choy, S. L.; Wu, S. Q.; Tan, Z. X.

2013-09-01

Global Navigation Satellite System (GNSS) radio occultation (RO) is an innovative meteorological remote sensing technique for measuring atmospheric parameters such as refractivity, temperature, water vapour and pressure for the improvement of numerical weather prediction (NWP) and global climate monitoring (GCM). GNSS RO has many unique characteristics including global coverage, long-term stability of observations, as well as high accuracy and high vertical resolution of the derived atmospheric profiles. One of the main error sources in GNSS RO observations that significantly affect the accuracy of the derived atmospheric parameters in the stratosphere is the ionospheric error. In order to mitigate the effect of this error, the linear ionospheric correction approach for dual-frequency GNSS RO observations is commonly used. However, the residual ionospheric errors (RIEs) can be still significant, especially when large ionospheric disturbances occur and prevail such as during the periods of active space weather. In this study, the RIEs were investigated under different local time, propagation direction and solar activity conditions and their effects on RO bending angles are characterised using end-to-end simulations. A three-step simulation study was designed to investigate the characteristics of the RIEs through comparing the bending angles with and without the effects of the RIEs. This research forms an important step forward in improving the accuracy of the atmospheric profiles derived from the GNSS RO technique.

Characterisation of capacitive field-effect sensors with a nanocrystalline-diamond film as transducer material for multi-parameter sensing.

PubMed

Abouzar, M H; Poghossian, A; Razavi, A; Williams, O A; Bijnens, N; Wagner, P; Schöning, M J

2009-01-01

The feasibility of a capacitive field-effect EDIS (electrolyte-diamond-insulator-semiconductor) platform for multi-parameter sensing is demonstrated by realising EDIS sensors with an O-terminated nanocrystalline-diamond (NCD) film as transducer material for the detection of pH and penicillin concentration as well as for the label-free electrical monitoring of adsorption and binding of charged macromolecules, like polyelectrolytes. The NCD films were grown on p-Si-SiO(2) substrates by microwave plasma-enhanced chemical vapour deposition. To obtain O-terminated surfaces, the NCD films were treated in an oxidising medium. The NCD-based field-effect sensors have been characterised by means of constant-capacitance method. The average pH sensitivity of the O-terminated NCD film was 40 mV/pH. A low detection limit of 5 microM and a high penicillin G sensitivity of 65-70 mV/decade has been obtained for an EDIS penicillin biosensor with the adsorptively immobilised enzyme penicillinase. Alternating potential changes, having tendency to decrease with increasing the number of adsorbed polyelectrolyte layers, have been observed after the layer-by-layer deposition of polyelectrolyte multilayers, using positively charged PAH (poly (allylamine hydrochloride)) and a negatively charged PSS (poly (sodium 4-styrene sulfonate)) as a model system. The response mechanism of the developed EDIS sensors is discussed.

Evaluation of Wear on Macro-Surface Textures Generated by ns Fiber Laser

NASA Astrophysics Data System (ADS)

Harish, V.; Soundarapandian, S.; Vijayaraghavan, L.; Bharatish, A.

2018-03-01

The demand for improved performance and long term reliability of mechanical systems dictate the use of advanced materials and surface engineering techniques. A small change in the surface topography can lead to substantial improvements in the tribological behaviour of the contact surfaces. One way of altering the surface topography is by surface texturing by introducing dimples or channels on the surfaces. Surface texturing is already a successful technique which finds a wide area of applications ranging from heavy industries to small scale devices. This paper reports the effect of macro texture shapes generated using a nanosecond fiber laser on wear of high carbon chromium steel used in large size bearings having rolling contacts. Circular and square shaped dimples were generated on the surface to assess the effect of sliding velocities on friction coefficient. Graphite was used as solid lubricant to minimise the effect of wear on textured surfaces. The laser parameters such as power, scan speed and passes were optimised to obtain macro circular and square dimples which was characterised using a laser confocal microscope. The friction coefficients of the circular and square dimples were observed to lie in the same range due to minimum wear on the surface. On the contrary, at medium and higher sliding velocities, square dimples exhibited lower friction coefficient values compared to circular dimples. The morphology of textured specimen was characterised using Scanning Electron Microscope.

Exponentially convergent state estimation for delayed switched recurrent neural networks.

PubMed

Ahn, Choon Ki

2011-11-01

This paper deals with the delay-dependent exponentially convergent state estimation problem for delayed switched neural networks. A set of delay-dependent criteria is derived under which the resulting estimation error system is exponentially stable. It is shown that the gain matrix of the proposed state estimator is characterised in terms of the solution to a set of linear matrix inequalities (LMIs), which can be checked readily by using some standard numerical packages. An illustrative example is given to demonstrate the effectiveness of the proposed state estimator.

The acute (immediate) effects of reflexology on arterial compliance in healthy volunteers: A randomised study.

PubMed

Rollinson, Kirsty; Jones, Jenny; Scott, Norma; Megson, Ian L; Leslie, Stephen J

2016-02-01

Reflexology is a widely used complementary therapy. The effects of reflexology on the cardiovascular system are not well characterised. Arterial stiffness (compliance) is a marker of vascular health. This study aimed to evaluate the effects of reflexology on arterial compliance in healthy volunteers. 12 healthy volunteers (1 male; 11 female; mean age 44.8 ± 10.8 yrs) received 10 min of reflexology on each foot in a single-blind randomised study. The main outcome measures were measurements of cardiovascular parameters including heart rate, blood pressure and arterial compliance (augmentation index). Reflexology had no significant effect on heart rate, blood pressure or augmentation index (all p > 0.05). In healthy volunteers, there were no consistent changes in haemodynamic parameters with a single brief reflexology treatment. Thus from a cardiovascular point of view, reflexology (as delivered) would appear to have a limited (if any) effect on the cardiovascular system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Image analysis for material characterisation

NASA Astrophysics Data System (ADS)

Livens, Stefan

In this thesis, a number of image analysis methods are presented as solutions to two applications concerning the characterisation of materials. Firstly, we deal with the characterisation of corrosion images, which is handled using a multiscale texture analysis method based on wavelets. We propose a feature transformation that deals with the problem of rotation invariance. Classification is performed with a Learning Vector Quantisation neural network and with combination of outputs. In an experiment, 86,2% of the images showing either pit formation or cracking, are correctly classified. Secondly, we develop an automatic system for the characterisation of silver halide microcrystals. These are flat crystals with a triangular or hexagonal base and a thickness in the 100 to 200 nm range. A light microscope is used to image them. A novel segmentation method is proposed, which allows to separate agglomerated crystals. For the measurement of shape, the ratio between the largest and the smallest radius yields the best results. The thickness measurement is based on the interference colours that appear for light reflected at the crystals. The mean colour of different thickness populations is determined, from which a calibration curve is derived. With this, the thickness of new populations can be determined accurately.

DecoFungi: a web application for automatic characterisation of dye decolorisation in fungal strains.

PubMed

Domínguez, César; Heras, Jónathan; Mata, Eloy; Pascual, Vico

2018-02-27

Fungi have diverse biotechnological applications in, among others, agriculture, bioenergy generation, or remediation of polluted soil and water. In this context, culture media based on color change in response to degradation of dyes are particularly relevant; but measuring dye decolorisation of fungal strains mainly relies on a visual and semiquantitative classification of color intensity changes. Such a classification is a subjective, time-consuming and difficult to reproduce process. DecoFungi is the first, at least up to the best of our knowledge, application to automatically characterise dye decolorisation level of fungal strains from images of inoculated plates. In order to deal with this task, DecoFungi employs a deep-learning model, accessible through a user-friendly web interface, with an accuracy of 96.5%. DecoFungi is an easy to use system for characterising dye decolorisation level of fungal strains from images of inoculated plates.

Physico-chemical characterisation, cytotoxic activity, and biocompatibility studies of tamoxifen-loaded solid lipid nanoparticles prepared via a temperature-modulated solidification method.

PubMed

Lakkadwala, Sushant; Nguyen, Sanko; Lawrence, Joseph; Nauli, Surya M; Nesamony, Jerry

2014-01-01

Solid lipid nanoparticles (SLNs) can efficiently and efficaciously incorporate anti-cancer agents. To prepare and characterise tamoxifen (TAM)-loaded SLNs. Glyceryl monostearate, Tween-80, and trehalose were used in SLNs. SLNs were tested via dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Characterisation studies revealed SLNs of about 540 nm with a negative surface charge and confirmed the entrapment of TAM in the SLNs. The entrapment efficiency was estimated to be 60%. The in vitro drug release profile demonstrated a gradual increase followed by a release plateau for several days. A drug concentration-dependent increase in cytotoxic activity was observed when the SLNs were evaluated in cell cultures. Biocompatible and stable lyophilised SLNs were successfully prepared and found to possess properties that may be utilised in an anti-cancer drug delivery system.

Negative ion beam characterisation in BATMAN by mini-STRIKE: Improved design and new measurements

NASA Astrophysics Data System (ADS)

Serianni, G.; Bonomo, F.; Brombin, M.; Cervaro, V.; Chitarin, G.; Cristofaro, S.; Delogu, R.; De Muri, M.; Fasolo, D.; Fonnesu, N.; Franchin, L.; Franzen, P.; Ghiraldelli, R.; Molon, F.; Muraro, A.; Pasqualotto, R.; Ruf, B.; Schiesko, L.; Tollin, M.; Veltri, P.

2015-04-01

The ITER project requires additional heating provided by two injectors of neutral beams resulting from the neutralisation of accelerated negative ions. To study and optimise negative ion production, the SPIDER test facility (particle energy 100keV; beam current 50A) is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon fibre carbon composite tiles. Some prototype tiles have been employed in 2012 as a small-scale version (mini-STRIKE) of the entire system to investigate the features of the beam from BATMAN at IPP-Garching. As the BATMAN beamlets are superposed at the measurement position, about 1m from the grounded grid, an actively cooled copper mask is located in front of the tiles; holes in the mask create an artificial beamlet structure. Recently the mini-STRIKE has been updated, taking into account the results obtained in the first campaign. In particular the spatial resolution of the system has been improved by increasing the number of the copper mask holes. Moreover a custom measurement system has been realized for the thermocouple signals and employed in BATMAN in view of its use in SPIDER. The present contribution gives a description of the new design of the system as well as of the thermocouple measurements system and its field test. A new series of measurements has been carried out in BATMAN. The BATMAN beam characterisation in different experimental conditions is presented.

Negative ion beam characterisation in BATMAN by mini-STRIKE: Improved design and new measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serianni, G., E-mail: gianluigi.serianni@igi.cnr.it; Brombin, M.; Cervaro, V.

The ITER project requires additional heating provided by two injectors of neutral beams resulting from the neutralisation of accelerated negative ions. To study and optimise negative ion production, the SPIDER test facility (particle energy 100keV; beam current 50A) is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon fibre carbon composite tiles. Some prototype tiles have been employed in 2012 as a small-scale version (mini-STRIKE) of the entire system to investigate the features ofmore » the beam from BATMAN at IPP-Garching. As the BATMAN beamlets are superposed at the measurement position, about 1m from the grounded grid, an actively cooled copper mask is located in front of the tiles; holes in the mask create an artificial beamlet structure. Recently the mini-STRIKE has been updated, taking into account the results obtained in the first campaign. In particular the spatial resolution of the system has been improved by increasing the number of the copper mask holes. Moreover a custom measurement system has been realized for the thermocouple signals and employed in BATMAN in view of its use in SPIDER. The present contribution gives a description of the new design of the system as well as of the thermocouple measurements system and its field test. A new series of measurements has been carried out in BATMAN. The BATMAN beam characterisation in different experimental conditions is presented.« less

Identification of phenanthrene derivatives in Aerides rosea (Orchidaceae) using the combined systems HPLC-ESI-HRMS/MS and HPLC-DAD-MS-SPE-UV-NMR.

PubMed

Cakova, Veronika; Urbain, Aurélie; Antheaume, Cyril; Rimlinger, Nicole; Wehrung, Patrick; Bonté, Frédéric; Lobstein, Annelise

2015-01-01

In our continued efforts to contribute to the general knowledge on the chemical diversity of orchids, we have decided to focus our investigations on the Aeridinae subtribe. Following our previous phytochemical study of Vanda coerulea, which has led to the identification of phenanthrene derivatives, a closely related species, Aerides rosea Lodd. ex Lindl. & Paxton, was chosen for investigation. To identify new secondary metabolites, and to avoid isolation of those already known, by means of the combined systems HPLC-DAD(diode-array detector) with high-resolution tandem mass spectrometry (HRMS/MS) and HPLC-DAD-MS-SPE(solid-phase extraction)-UV-NMR. A dereplication strategy was developed using a HPLC-DAD-HRMS/MS targeted method and applied to fractions from A. rosea stem extract. Characterisation of unknown minor compounds was then performed using the combined HPLC-DAD-MS-SPE-UV-NMR system. The dereplication method allowed the characterisation of four compounds (gigantol, imbricatin, methoxycoelonin and coelonin), previously isolated from Vanda coerulea stem extract. The analyses of two fractions permitted the identification of five additional minor constituents including one phenanthropyran, two phenanthrene and two dihydrophenanthrene derivatives. The full set of NMR data of each compound was obtained from microgram quantities. Nine secondary metabolites were characterised in A. rosea stems, utilising HPLC systems combined with high-resolution analytical systems. Two of them are newly described phenanthrene derivatives: aerosanthrene (5-methoxyphenanthrene-2,3,7-triol) and aerosin (3-methoxy-9,10-dihydro-2,5,7-phenanthrenetriol). Copyright © 2014 John Wiley & Sons, Ltd.

Art and the brain: a view from dementia.

PubMed

Gretton, Cosima; ffytche, Dominic H

2014-02-01

Art making encompasses a range of perceptual and cognitive functions involving widely distributed brain systems. The dementias impact on these systems in different ways, raising the possibility that each dementia has a unique artistic signature. Here we use a review of the visual art of 14 artists with dementia (five Alzheimer's disease, seven fronto-temporal dementia and two dementia with Lewy bodies) to further our understanding of the neurobiological constituents of art production and higher artistic function. Artists with Alzheimer's disease had prominent changes in spatial aspects of their art and attributes of colour and contrast. These qualities were preserved in the art of fronto-temporal dementia, which was characterised by perseverative themes and a shift towards realistic representation. The art of dementia with Lewy Bodies was characterised by simple, bizarre content. The limitations of using visual aspects of individual artworks to infer the impact of dementia on art production are discussed with the need for a wider perspective encompassing changes in cognition, emotion, creativity and artistic personality. A novel classificatory scheme is presented to help characterise neural mechanisms of higher artistic functions in future studies. Copyright © 2013 John Wiley & Sons, Ltd.

Effect of interparticle interactions on size determination of zirconia and silica based systems – A comparison of SAXS, DLS, BET, XRD and TEM

PubMed Central

Pabisch, Silvia; Feichtenschlager, Bernhard; Kickelbick, Guido; Peterlik, Herwig

2012-01-01

The aim of this work is a systematic comparison of size characterisation methods for two completely different model systems of oxide nanoparticles, i.e. amorphous spherical silica and anisotropic facet-shaped crystalline zirconia. Size and/or size distribution were determined in a wide range from 5 to 70 nm using small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), nitrogen sorption (BET), X-ray diffraction (XRD) and transmission electron microscopy (TEM). A nearly perfect coincidence was observed only for SAXS and TEM for both types of particles. For zirconia nanoparticles considerable differences between different measurement methods were observed. PMID:22347721

Diagnosis, pathophysiology, and management of cluster headache.

PubMed

Hoffmann, Jan; May, Arne

2018-01-01

Cluster headache is a trigeminal autonomic cephalalgia characterised by extremely painful, strictly unilateral, short-lasting headache attacks accompanied by ipsilateral autonomic symptoms or the sense of restlessness and agitation, or both. The severity of the disorder has major effects on the patient's quality of life and, in some cases, might lead to suicidal ideation. Cluster headache is now thought to involve a synchronised abnormal activity in the hypothalamus, the trigeminovascular system, and the autonomic nervous system. The hypothalamus appears to play a fundamental role in the generation of a permissive state that allows the initiation of an episode, whereas the attacks are likely to require the involvement of the peripheral nervous system. Triptans are the most effective drugs to treat an acute cluster headache attack. Monoclonal antibodies against calcitonin gene-related peptide, a crucial neurotransmitter of the trigeminal system, are under investigation for the preventive treatment of cluster headache. These studies will increase our understanding of the disorder and perhaps reveal other therapeutic targets. Copyright © 2018 Elsevier Ltd. All rights reserved.

Colour analysis and verification of CCTV images under different lighting conditions

NASA Astrophysics Data System (ADS)

Smith, R. A.; MacLennan-Brown, K.; Tighe, J. F.; Cohen, N.; Triantaphillidou, S.; MacDonald, L. W.

2008-01-01

Colour information is not faithfully maintained by a CCTV imaging chain. Since colour can play an important role in identifying objects it is beneficial to be able to account accurately for changes to colour introduced by components in the chain. With this information it will be possible for law enforcement agencies and others to work back along the imaging chain to extract accurate colour information from CCTV recordings. A typical CCTV system has an imaging chain that may consist of scene, camera, compression, recording media and display. The response of each of these stages to colour scene information was characterised by measuring its response to a known input. The main variables that affect colour within a scene are illumination and the colour, orientation and texture of objects. The effects of illumination on the appearance of colour of a variety of test targets were tested using laboratory-based lighting, street lighting, car headlights and artificial daylight. A range of typical cameras used in CCTV applications, common compression schemes and representative displays were also characterised.

A Diffraction Method of Study of Thermal Quasiorder in a Finite Two-Dimensional Harmonic Lattice

NASA Astrophysics Data System (ADS)

Aranda, P.; Croset, B.

1995-09-01

Due to the non-existence of long-range order, the diffraction peaks of 2D-solids are considered to have a power-law shape g_p^{η-2}. Taking into account the finite size effects and calculating the powder average, we show that this power-law behaviour appears only for high q_p and then for very small intensities. It is therefore quite difficult and hazardous to characterise the quasiorder by using this asymptotic behaviour. Although the shape of the central part of the peak cannot be used to characterise the quasiorder, we show that, for a fairly good resolution, it is possible to determine η using this central part. This determination can be done irrespectively with the other details of the system by comparing the peak width to its value at low temperature, i.e., at low value of η. By using two diffraction peaks, we propose the simple relation: η(Q_{B_1})/Q_{B_1}^2=η(Q_{B_2})/Q_{B_2}^2 as a check of the two-dimensional quasiorder.

Study on aluminium-based single films.

PubMed

Vinod Kumar, G S; García-Moreno, F; Babcsán, N; Brothers, A H; Murty, B S; Banhart, J

2007-12-28

In the present paper the authors studied isolated metallic films made from the same material used for making metallic foams, and then characterised their properties. Metal films were made from a liquid aluminium alloy reinforced with ceramic particles of known concentration. Melts without such particles were also investigated. It is shown that stable films could not be made from Al-Si alloy having no particles, and just extremely thin and fragile films could be made from commercially-pure Al. In contrast, aluminium alloys containing particles such as SiC and TiB(2) allowed pulling thin, stable films, which did not rupture. Significant thinning of films was observed when the particle concentration in the melt decreased. By in situ X-ray monitoring of liquid films during pulling, film thickness and drainage effects within the liquid film could be studied. The morphology and microstructure of films was characterised after solidification. Our work shows that the question of how foams are stabilised can be studied using a simplified system such as a film, instead of having to deal with the multitude of different structural elements present in a foam.

Relationships between fractures

NASA Astrophysics Data System (ADS)

Peacock, D. C. P.; Sanderson, D. J.; Rotevatn, A.

2018-01-01

Fracture systems comprise many fractures that may be grouped into sets based on their orientation, type and relative age. The fractures are often arranged in a network that involves fracture branches that interact with one another. Interacting fractures are termed geometrically coupled when they share an intersection line and/or kinematically coupled when the displacements, stresses and strains of one fracture influences those of the other. Fracture interactions are characterised in terms of the following. 1) Fracture type: for example, whether they have opening (e.g., joints, veins, dykes), closing (stylolites, compaction bands), shearing (e.g., faults, deformation bands) or mixed-mode displacements. 2) Geometry (e.g., relative orientations) and topology (the arrangement of the fractures, including their connectivity). 3) Chronology: the relative ages of the fractures. 4) Kinematics: the displacement distributions of the interacting fractures. It is also suggested that interaction can be characterised in terms of mechanics, e.g., the effects of the interaction on the stress field. It is insufficient to describe only the components of a fracture network, with fuller understanding coming from determining the interactions between the different components of the network.

Spectral autofluorescence imaging of the retina for drusen detection

NASA Astrophysics Data System (ADS)

Foubister, James J.; Gorman, Alistair; Harvey, Andy; Hemert, Jano van

2018-02-01

The presence and characteristics of drusen in retinal images, namely their size, location, and distribution, can be used to aid in the diagnosis and monitoring of Age Related Macular Degeneration (AMD); one of the leading causes for blindness in the elderly population. Current imaging techniques are effective at determining the presence and number of drusen, but fail when it comes to classifying their size and form. These distinctions are important for correctly characterising the disease, especially in the early stages where the development of just one larger drusen can indicate progression. Another challenge for automated detection is in distinguishing them from other retinal features, such as cotton wool spots. We describe the development of a multi-spectral scanning-laser ophthalmoscope that records images of retinal autofluorescence (AF) in four spectral bands. This will offer the potential to detect drusen with improved contrast based on spectral discrimination for automated classification. The resulting improved specificity and sensitivity for their detection offers more reliable characterisation of AMD. We present proof of principle images prior to further system optimisation and clinical trials for assessment of enhanced detection of drusen.

Continuum and atomistic description of excess electrons in TiO2

NASA Astrophysics Data System (ADS)

Maggio, Emanuele; Martsinovich, Natalia; Troisi, Alessandro

2016-02-01

The modelling of an excess electron in a semiconductor in a prototypical dye sensitised solar cell is carried out using two complementary approaches: atomistic simulation of the TiO2 nanoparticle surface is complemented by a dielectric continuum model of the solvent-semiconductor interface. The two methods are employed to characterise the bound (excitonic) states formed by the interaction of the electron in the semiconductor with a positive charge opposite the interface. Density-functional theory (DFT) calculations show that the excess electron in TiO2 in the presence of a counterion is not fully localised but extends laterally over a large region, larger than system sizes accessible to DFT calculations. The numerical description of the excess electron at the semiconductor-electrolyte interface based on the continuum model shows that the exciton is also delocalised over a large area: the exciton radius can have values from tens to hundreds of Ångströms, depending on the nature of the semiconductor (characterised by the dielectric constant and the electron effective mass in our model).

Validation of a sensitive DNA walking strategy to characterise unauthorised GMOs using model food matrices mimicking common rice products.

PubMed

Fraiture, Marie-Alice; Herman, Philippe; Taverniers, Isabel; De Loose, Marc; Van Nieuwerburgh, Filip; Deforce, Dieter; Roosens, Nancy H

2015-04-15

To identify unauthorised GMOs in food and feed matrices, an integrated approach has recently been developed targeting pCAMBIA family vectors, highly present in transgenic plants. Their presence is first assessed by qPCR screening and is subsequently confirmed by characterising the transgene flanking regions, using DNA walking. Here, the DNA walking performance has been thoroughly tested for the first time, regarding the targeted DNA quality and quantity. Several assays, on model food matrices mimicking common rice products, have allowed to determine the limit of detection as well as the potential effects of food mixture and processing. This detection system allows the identification of transgenic insertions as low as 10 HGEs and was not affected by the presence of untargeted DNA. Moreover, despite the clear impact of food processing on DNA quality, this method was able to cope with degraded DNA. Given its specificity, sensitivity, reliability, applicability and practicability, the proposed approach is a key detection tool, easily implementable in enforcement laboratories. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evidence for the cytotoxic effects of Mycobacterium tuberculosis phospholipase C towards macrophages.

PubMed

Bakala N'goma, J C; Schué, M; Carrière, F; Geerlof, A; Canaan, S

2010-12-01

Phospholipase Cs (PLCs) contribute importantly to the virulence and pathogenicity of several bacteria. It has been reported in previous studies that mutations in the four predicted plc genes of Mycobacterium tuberculosis inhibit the growth of these bacteria during the late phase of infection in mice. These enzymes have not yet been fully characterised, mainly because they are not easy to produce in large quantities. With a view to elucidating the role of all Mycobacterium tuberculosis phospholipase Cs (PLC-A, PLC-B, PLC-C and PLC-D), a large amount of active, soluble recombinant PLCs, were expressed and purified using Mycobacterium smegmatis as expression system. These enzymes showed different pH activity profiles. PLC-C was found to be the most active of the four recombinant PLCs under acidic conditions. All the enzymes tested induced cytotoxic effects on mouse macrophage RAW 264.7 cell lines, via direct or indirect enzymatic hydrolysis of cell membrane phospholipids. These results open new prospects for characterising biochemical and structural features of Mycobacterium tuberculosis PLCs, which might lead to the identification of novel anti-tuberculosis drug targets. All mycobacterial phospholipase Cs can now be studied in order to determine their role in the virulence and pathogenicity of bacteria of this kind. 2010 Elsevier B.V. All rights reserved.

The Shift of the University Paradigm and Reform of the Korean University Systems

ERIC Educational Resources Information Center

Lee, Hyun-Chong

2005-01-01

The 21st century society is characterised as a knowledge-based society, education mobility society, and cyber schooling society. This new paradigm of university enables us to restructure the university system in Korea. To establish an efficient and competitive education system, it is essential to change the current university system. Restructuring…

Characterising the Development of the Understanding of Human Body Systems in High-School Biology Students--A Longitudinal Study

ERIC Educational Resources Information Center

Snapir, Zohar; Eberbach, Catherine; Ben-Zvi-Assaraf, Orit; Hmelo-Silver, Cindy; Tripto, Jaklin

2017-01-01

Science education today has become increasingly focused on research into complex natural, social and technological systems. In this study, we examined the development of high-school biology students' systems understanding of the human body, in a three-year longitudinal study. The development of the students' system understanding was evaluated…

A blueprint for the synthesis and characterisation of thin graphene oxide with controlled lateral dimensions for biomedicine

NASA Astrophysics Data System (ADS)

Filipe Rodrigues, Artur; Newman, Leon; Lozano, Neus; Mukherjee, Sourav P.; Fadeel, Bengt; Bussy, Cyrill; Kostarelos, Kostas

2018-07-01

Graphene-based materials (GBMs) have ignited a revolution in material science and technology, with electronic, optical and mechanical properties that are of relevant interest for a wide range of applications. To support the development of these enabling technologies, a global research effort has been invested to assess their hazard and biocompatibility. Different production methods have however generated a diverse collection of GBMs with different physicochemical properties, leading to a variety of biological outcomes that are still not fully understood. To better understand the biological interactions of GBMs with biological systems and allow the design of safer materials, a thorough physicochemical characterisation is therefore highly recommended. The aim of the present work was to produce a blueprint for the synthesis and characterisation of non-pyrogenic graphene oxide (GO) flakes with three different controlled lateral dimensions, which could be further used for either hazard assessment or biomedical proof-of-concept studies. A battery of techniques used to characterise the physicochemical properties of the GO samples included atomic force microscopy, transmission electron microscopy, Fourier-transformed infra-red spectroscopy, x-ray photoelectron spectroscopy and Raman spectroscopy. The combination of these different techniques confirmed that only the lateral dimension varied among the GO materials produced, without significant change in any other of their fundamental physicochemical properties, such as the thickness or surface chemistry. The proposed systematic approach in GO batch production for biology will hopefully contribute to a better understanding of the material properties that govern their interactions with biological systems and offer a blueprint towards standardisation of biologically relevant 2D materials.

Characterisation of Pomegranate-Husk Polyphenols and Semi-Preparative Fractionation of Punicalagin.

PubMed

Aguilar-Zárate, Pedro; Wong-Paz, Jorge E; Michel, Mariela; Buenrostro-Figueroa, Juan; Díaz, Hugo R; Ascacio, Juan A; Contreras-Esquivel, Juan C; Gutiérrez-Sánchez, Gerardo; Aguilar, Cristóbal N

2017-09-01

Pomegranate-husk is the main by-product generated from the pomegranate industry. It is a potential source of compounds highly appreciated by different costumers. Punicalagin is the main compound present in pomegranate-husk. To characterise the pomegranate-husk total polyphenols by HPLC-ESI-MS and to establish a method for the recovery of punicalagin using a medium pressure liquid chromatography (MPLC) system. The characterisation of total pomegranate-husk polyphenols was carried out using liquid chromatography coupled to mass spectrometry. Thus, 200 mg of pomegranate-husk polyphenols were fractionated by MPLC. The isolated punicalagin was characterised by HPLC-MS and was tested as standard reagent for the measurement of its scavenging capacity reducing DPPH and ABTS radicals. Twenty peaks were identified by analytical HPLC-MS analysis from the pomegranate-husk polyphenols. The main compounds were the punicalagin anomers, punicalin and ellagic acid. The MPLC method allowed three fractions to be obtained. In fraction three 39.40 ± 8.06 mg of punicalagin anomers (purity > 97.9%) were recovered. The scavenging capacity of punicalagin showed an IC 50 of 109.53 and 151.50 μg/mL for DPPH and ABTS radicals, respectively. The MPLC system was an excellent tool for the separation of the main ellagitannins from pomegranate husk and for the isolation of punicalagin anomers. Fraction three was rich in high purity punicalagin anomers. The IC 50 was obtained for DPPH and ABTS radicals. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Mapping forces in a 3D elastic assembly of grains

NASA Astrophysics Data System (ADS)

Saadatfar, Mohammad; Sheppard, Adrian P.; Senden, Tim J.; Kabla, Alexandre J.

2012-01-01

Our understanding of the elasticity and rheology of disordered materials, such as granular piles, foams, emulsions or dense suspensions relies on improving experimental tools to characterise their behaviour at the particle scale. While 2D observations are now routinely carried out in laboratories, 3D measurements remain a challenge. In this paper, we use a simple model system, a packing of soft elastic spheres, to illustrate the capability of X-ray microtomography to characterise the internal structure and local behaviour of granular systems. Image analysis techniques can resolve grain positions, shapes and contact areas; this is used to investigate the material's microstructure and its evolution upon strain. In addition to morphological measurements, we develop a technique to quantify contact forces and estimate the internal stress tensor. As will be illustrated in this paper, this opens the door to a broad array of static and dynamical measurements in 3D disordered systems.

Characterisation of an Exploding Foil Initiator (EFI) system

NASA Astrophysics Data System (ADS)

Davies, H. R.; Chapman, D. J.; Vine, T. A.; Proud, W. G.

2009-06-01

Exploding Foil Initiators (EFIs) provide a safe and reliable means of detonation of explosives. They are highly insensitive to mechanical shock and electrical interference, requiring a specific high current pulse for initiation. The use of only insensitive secondary explosives and not more sensitive primary explosives further improves safety. When a high current is passed through the metal bridge, a plasma is formed as the metal can not expand beyond the polymer film layer above. This causes the film to expand forming a bubble or shearing off to form a flyer. These flyers can then be used to initiate secondary explosives. Due to the very high speed at which these systems operate, high speed streak photography was used to characterise the behaviour of the polymer film flyers produced. This paper will report the preliminary findings on the mechanical, electrical and velocity changes seen in some proprietary systems.

Reducing tilt-to-length coupling for the LISA test mass interferometer

NASA Astrophysics Data System (ADS)

Tröbs, M.; Schuster, S.; Lieser, M.; Zwetz, M.; Chwalla, M.; Danzmann, K.; Fernández Barránco, G.; Fitzsimons, E. D.; Gerberding, O.; Heinzel, G.; Killow, C. J.; Perreur-Lloyd, M.; Robertson, D. I.; Schwarze, T. S.; Wanner, G.; Ward, H.

2018-05-01

Objects sensed by laser interferometers are usually not stable in position or orientation. This angular instability can lead to a coupling of angular tilt to apparent longitudinal displacement—tilt-to-length coupling (TTL). In LISA this is a potential noise source for both the test mass interferometer and the long-arm interferometer. We have experimentally investigated TTL coupling in a setup representative for the LISA test mass interferometer and used this system to characterise two different imaging systems (a two-lens design and a four-lens design) both designed to minimise TTL coupling. We show that both imaging systems meet the LISA requirement of  ±25 μm rad‑1 for interfering beams with relative angles of up to  ±300 μrad. Furthermore, we found a dependency of the TTL coupling on beam properties such as the waist size and location, which we characterised both theoretically and experimentally.

[Governance of primary health-care-based health-care organization].

PubMed

Báscolo, Ernesto

2010-01-01

An analytical framework was developed for explaining the conditions for the effectiveness of different strategies promoting integrated primary health-care (PHC) service-based systems in Latin-America. Different modes of governance (clan, incentives and hierarchy) were characterised from a political economics viewpoint for representing alternative forms of regulation promoting innovation in health-service-providing organisations. The necessary conditions for guaranteeing the modes of governance's effectiveness are presented, as are their implications in terms of posts in play. The institutional construction of an integrated health system is interpreted as being a product of a social process in which different modes of governance are combined, operating with different ways of resolving normative aspects for regulating service provision (with the hierarchical mode), resource distribution (with the incentives mode) and on the social values legitimising such process (with the clan mode).

Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

PubMed

Henning, Joerg; Pfeiffer, Dirk U; Stevenson, Mark; Yulianto, Didik; Priyono, Walujo; Meers, Joanne

2016-01-01

Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI) virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised.

Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

PubMed Central

Henning, Joerg; Pfeiffer, Dirk U.; Stevenson, Mark; Yulianto, Didik; Priyono, Walujo; Meers, Joanne

2016-01-01

Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI) virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised. PMID:27019344

Quantitative Characterisation and Analysis of Siliciclastic Fluvial Depositional Systems Using 3D Digital Outcrop Models

NASA Astrophysics Data System (ADS)

Burnham, Brian Scott

Outcrop analogue studies of fluvial sedimentary systems are often undertaken to identify spatial and temporal characteristics (e.g. stacking patterns, lateral continuity, lithofacies proportions). However, the lateral extent typically exceeds that of the exposure, and/or the true width and thickness are not apparent. Accurate characterisation of fluvial sand bodies is integral for accurate identification and subsequent modelling of aquifer and hydrocarbon reservoir architecture. The studies presented in this thesis utilise techniques that integrate lidar, highresolution photography and differential geospatial measurements, to create accurate three-dimensional (3D) digital outcrop models (DOMs) of continuous 3D and laterally extensive 2D outcrop exposures. The sedimentary architecture of outcrops in the medial portion of a large Distributive Fluvial System (DFS) (Huesca fluvial fan) in the Ebro Basin, north-east Spain, and in the fluvio-deltaic succession of the Breathitt Group in the eastern Appalachian Basin, USA, are evaluated using traditional sedimentological and digital outcrop analytical techniques. The major sand bodies in the study areas are quantitatively analysed to accurately characterise spatial and temporal changes in sand body architecture, from two different outcrop exposure types and scales. Several stochastic reservoir simulations were created to approximate fluvial sand body lithological component and connectivity within the medial portion of the Huesca DFS. Results demonstrate a workflow and current methodology adaptation of digital outcrop techniques required for each study to approximate true geobody widths, thickness and characterise architectural patterns (internal and external) of major fluvial sand bodies interpreted as products of DFSs in the Huesca fluvial fan, and both palaeovalleys and progradational DFSs in the Pikeville and Hyden Formations in the Breathitt Group. The results suggest key geostatistical metrics, which are translatable across any fluvial system that can be used to analyse 3D digital outcrop data, and identify spatial attributes of sand bodies to identify their genetic origin and lithological component within fluvial reservoir systems, and the rock record. 3D quantitative analysis of major sand bodies have allowed more accurate width vs. thickness relationships within the La Serreta area, showing a vertical increase in width and channel-fill facies, and demonstrates a 22% increase of in-channel facies from previous interpretations. Additionally, identification of deposits that are products of a nodal avulsion event have been characterised and are interpreted to be the cause for the increase in width and channel-fill facies. Furthermore, analysis of the Pikeville and Hyden Fms contain sand bodies of stacked distributaries and palaeovalleys, as previously interpreted, and demonstrates that a 3D spatial approach to determine basin-wide architectural trends is integral to identifying the genetic origin, and preservation potential of sand bodies of both palaeovalleys and distributive fluvial systems. The resultant geostatistics assimilated in the thesis demonstrates the efficacy of integrated lidar studies of outcrop analogues, and provide empirical relationships which can be applied to subsurface analogues for reservoir model development and the distribution of both DFS and palaeovalley depositional systems in the rock record.

Conceptual uncertainty in crystalline bedrock: Is simple evaluation the only practical approach?

USGS Publications Warehouse

Geier, J.; Voss, C.I.; Dverstorp, B.

2002-01-01

A simple evaluation can be used to characterise the capacity of crystalline bedrock to act as a barrier to releases of radionuclides from a nuclear waste repository. Physically plausible bounds on groundwater flow and an effective transport-resistance parameter are estimated based on fundamental principles and idealised models of pore geometry. Application to an intensively characterised site in Sweden shows that, due to high spatial variability and uncertainty regarding properties of transport paths, the uncertainty associated with the geological barrier is too high to allow meaningful discrimination between good and poor performance. Application of more complex (stochastic-continuum and discrete-fracture-network) models does not yield a significant improvement in the resolution of geologic-barrier performance. Comparison with seven other less intensively characterised crystalline study sites in Sweden leads to similar results, raising a question as to what extent the geological barrier function can be characterised by state-of-the art site investigation methods prior to repository construction. A simple evaluation provides a simple and robust practical approach for inclusion in performance assessment.

Characterisation of aerosol combustible mixtures generated using condensation process

NASA Astrophysics Data System (ADS)

Saat, Aminuddin; Dutta, Nilabza; Wahid, Mazlan A.

2012-06-01

An accidental release of a liquid flammable substance might be formed as an aerosol (droplet and vapour mixture). This phenomenon might be due to high pressure sprays, pressurised liquid leaks and through condensation when hot vapour is rapidly cooled. Such phenomena require a fundamental investigation of mixture characterisation prior to any subsequent process such as evaporation and combustion. This paper describes characterisation study of droplet and vapour mixtures generated in a fan stirred vessel using condensation technique. Aerosol of isooctane mixtures were generated by expansion from initially a premixed gaseous fuel-air mixture. The distribution of droplets within the mixture was characterised using laser diagnostics. Nearly monosized droplet clouds were generated and the droplet diameter was defined as a function of expansion time. The effect of changes in pressure, temperature, fuel-air fraction and expansion ratio on droplet diameter was evaluated. It is shown that aerosol generation by expansion was influenced by the initial pressure and temperature, equivalence ratio and expansion rates. All these parameters affected the onset of condensation which in turn affected the variation in droplet diameter.

USEtox - The UNEP-SETAC toxicity model: recommended characterisation factors for human toxicity and freshwater ecotoxicity in Life Cycle Impact Assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenbaum, Ralph K.; Bachmann, Till M.; Swirsky Gold, Lois

2008-02-03

Background, Aim and Scope. In 2005 a comprehensive comparison of LCIA toxicity characterisation models was initiated by the UNEP-SETAC Life Cycle Initiative, directly involving the model developers of CalTOX, IMPACT 2002, USES-LCA, BETR, EDIP, WATSON, and EcoSense. In this paper we describe this model-comparison process and its results--in particular the scientific consensus model developed by the model developers. The main objectives of this effort were (i) to identify specific sources of differences between the models' results and structure, (ii) to detect the indispensable model components, and (iii) to build a scientific consensus model from them, representing recommended practice. Methods. Amore » chemical test set of 45 organics covering a wide range of property combinations was selected for this purpose. All models used this set. In three workshops, the model comparison participants identified key fate, exposure and effect issues via comparison of the final characterisation factors and selected intermediate outputs for fate, human exposure and toxic effects for the test set applied to all models. Results. Through this process, we were able to reduce inter-model variation from an initial range of up to 13 orders of magnitude down to no more than 2 orders of magnitude for any substance. This led to the development of USEtox, a scientific consensus model that contains only the most influential model elements. These were, for example, process formulations accounting for intermittent rain, defining a closed or open system environment, or nesting an urban box in a continental box. Discussion. The precision of the new characterisation factors (CFs) is within a factor of 100-1000 for human health and 10-100 for freshwater ecotoxicity of all other models compared to 12 orders of magnitude variation between the CFs of each model respectively. The achieved reduction of inter-model variability by up to 11 orders of magnitude is a significant improvement.Conclusions. USEtox provides a parsimonious and transparent tool for human health and ecosystem CF estimates. Based on a referenced database, it has now been used to calculate CFs for several thousand substances and forms the basis of the recommendations from UNEP-SETAC's Life Cycle Initiative regarding characterization of toxic impacts in Life Cycle Assessment. Recommendations and Perspectives. We provide both recommended and interim (not recommended and to be used with caution) characterisation factors for human health and freshwater ecotoxicity impacts. After a process of consensus building among stakeholders on a broad scale as well as several improvements regarding a wider and easier applicability of the model, USEtox will become available to practitioners for the calculation of further CFs.« less

Design, fabrication and characterisation of a microfluidic time-temperature indicator

NASA Astrophysics Data System (ADS)

Schmitt, P.; Wedrich, K.; Müller, L.; Mehner, H.; Hoffmann, M.

2017-11-01

This paper describes a concept for a passive microfluidic time-temperature indicator (TTI) intended for intelligent food packaging. A microfluidic system is presented that makes use of the temperature-dependent flow of suitable food ingredients in a microcapillary. Based on the creeping distance inside the capillary, the time-temperature integral can be determined. A demonstrator of the microsystem has been designed, fabricated and characterised using liquid sugar alcohols as indicator fluids. To enable a first wireless read-out of the passive TTI, the sensor was read out using a commercial RFID equipment, and capacitive measurements have been carried out.

Gamma-ray imaging system for real-time measurements in nuclear waste characterisation

NASA Astrophysics Data System (ADS)

Caballero, L.; Albiol Colomer, F.; Corbi Bellot, A.; Domingo-Pardo, C.; Leganés Nieto, J. L.; Agramunt Ros, J.; Contreras, P.; Monserrate, M.; Olleros Rodríguez, P.; Pérez Magán, D. L.

2018-03-01

A compact, portable and large field-of-view gamma camera that is able to identify, locate and quantify gamma-ray emitting radioisotopes in real-time has been developed. The device delivers spectroscopic and imaging capabilities that enable its use it in a variety of nuclear waste characterisation scenarios, such as radioactivity monitoring in nuclear power plants and more specifically for the decommissioning of nuclear facilities. The technical development of this apparatus and some examples of its application in field measurements are reported in this article. The performance of the presented gamma-camera is also benchmarked against other conventional techniques.

Open quantum generalisation of Hopfield neural networks

NASA Astrophysics Data System (ADS)

Rotondo, P.; Marcuzzi, M.; Garrahan, J. P.; Lesanovsky, I.; Müller, M.

2018-03-01

We propose a new framework to understand how quantum effects may impact on the dynamics of neural networks. We implement the dynamics of neural networks in terms of Markovian open quantum systems, which allows us to treat thermal and quantum coherent effects on the same footing. In particular, we propose an open quantum generalisation of the Hopfield neural network, the simplest toy model of associative memory. We determine its phase diagram and show that quantum fluctuations give rise to a qualitatively new non-equilibrium phase. This novel phase is characterised by limit cycles corresponding to high-dimensional stationary manifolds that may be regarded as a generalisation of storage patterns to the quantum domain.

Chemical Characterisation of the Coarse and Fine Particulate Matter in the Environment of an Underground Railway System: Cytotoxic Effects and Oxidative Stress—A Preliminary Study

PubMed Central

Spagnolo, Anna Maria; Ottria, Gianluca; Perdelli, Fernanda; Cristina, Maria Luisa

2015-01-01

Background: Exposure to the particulate matter produced in underground railway systems is arousing increasing scientific interest because of its health effects. The aim of our study was to evaluate the airborne concentrations of PM10 and three sub-fractions of PM2.5 in an underground railway system environment in proximity to platforms and in underground commercial areas within the system, and to compare these with the outdoor airborne concentrations. We also evaluated the metal components, the cytotoxic properties of the various fractions of particulate matter (PM) and their capacity to induce oxidative stress. Method: We collected the coarse fraction (5–10 µm) and the fine fractions (1–2.5 µm; 0.5–1 µm; 0.25–0.5 µm). Chemical characterisation was determined by means of spectrometry. Cytotoxicity and oxidative stress were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Reactive Oxygen Species (ROS) assessment. Results: The concentrations of both PM10 and PM2.5 proved to be similar at the three sampling sites. Iron and other transition metals displayed a greater concentration at the subway platform than at the other two sites. The 2.5–10 µm and 1–2.5 µm fractions of PM from all three sampling sites determined a greater increase in ROS; the intensity of oxidative stress progressively declined as particle diameter diminished. Moreover, ROS concentrations were correlated with the concentrations of some transition metals, namely Mn, Cr, Ti, Fe, Cu, Zn, Ni and Mo. All particulate matter fractions displayed lower or similar ROS values between platform level and the outdoor air. Conclusions: The present study revealed that the underground railway environment at platform level, although containing higher concentrations of some particularly reactive metallic species, did not display higher cytotoxicity and oxidative stress levels than the outdoor air. PMID:25872016

Chemical characterisation of the coarse and fine particulate matter in the environment of an underground railway system: cytotoxic effects and oxidative stress-a preliminary study.

PubMed

Spagnolo, Anna Maria; Ottria, Gianluca; Perdelli, Fernanda; Cristina, Maria Luisa

2015-04-13

Exposure to the particulate matter produced in underground railway systems is arousing increasing scientific interest because of its health effects. The aim of our study was to evaluate the airborne concentrations of PM10 and three sub-fractions of PM2.5 in an underground railway system environment in proximity to platforms and in underground commercial areas within the system, and to compare these with the outdoor airborne concentrations. We also evaluated the metal components, the cytotoxic properties of the various fractions of particulate matter (PM) and their capacity to induce oxidative stress. We collected the coarse fraction (5-10 µm) and the fine fractions (1-2.5 µm; 0.5-1 µm; 0.25-0.5 µm). Chemical characterisation was determined by means of spectrometry. Cytotoxicity and oxidative stress were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Reactive Oxygen Species (ROS) assessment. The concentrations of both PM10 and PM2.5 proved to be similar at the three sampling sites. Iron and other transition metals displayed a greater concentration at the subway platform than at the other two sites. The 2.5-10 µm and 1-2.5 µm fractions of PM from all three sampling sites determined a greater increase in ROS; the intensity of oxidative stress progressively declined as particle diameter diminished. Moreover, ROS concentrations were correlated with the concentrations of some transition metals, namely Mn, Cr, Ti, Fe, Cu, Zn, Ni and Mo. All particulate matter fractions displayed lower or similar ROS values between platform level and the outdoor air. The present study revealed that the underground railway environment at platform level, although containing higher concentrations of some particularly reactive metallic species, did not display higher cytotoxicity and oxidative stress levels than the outdoor air.

The matrix effect in secondary ion mass spectrometry

NASA Astrophysics Data System (ADS)

Seah, M. P.; Shard, A. G.

2018-05-01

Matrix effects in the secondary ion mass spectrometry (SIMS) of selected elemental systems have been analyzed to investigate the applicability of a mathematical description of the matrix effect, called here the charge transfer (CT) model. This model was originally derived for proton exchange and organic positive secondary ions, to characterise the enhancement or suppression of intensities in organic binary systems. In the systems considered in this paper protons are specifically excluded, which enables an assessment of whether the model applies for electrons as well. The present importance is in organic systems but, here we analyse simpler inorganic systems. Matrix effects in elemental systems cannot involve proton transfer if there are no protons present but may be caused by electron transfer and so electron transfer may also be involved in the matrix effects for organic systems. There are general similarities in both the magnitudes of the ion intensities as well as the matrix effects for both positive and negative secondary ions in both systems and so the CT model may be more widely applicable. Published SIMS analyses of binary elemental mixtures are analyzed. The data of Kim et al., for the Pt/Co system, provide, with good precision, data for such a system. This gives evidence for the applicability of the CT model, where electron, rather than proton, transfer is the matrix enhancing and suppressing mechanism. The published data of Prudon et al., for the important Si/Ge system, provides further evidence for the effects for both positive and negative secondary ions and allows rudimentary rules to be developed for the enhancing and suppressing species.

The Planetary Terrestrial Analogues Library (PTAL)

NASA Astrophysics Data System (ADS)

Werner, S. C.; Dypvik, H.; Poulet, F.; Rull Perez, F.; Bibring, J.-P.; Bultel, B.; Casanova Roque, C.; Carter, J.; Cousin, A.; Guzman, A.; Hamm, V.; Hellevang, H.; Lantz, C.; Lopez-Reyes, G.; Manrique, J. A.; Maurice, S.; Medina Garcia, J.; Navarro, R.; Negro, J. I.; Neumann, E. R.; Pilorget, C.; Riu, L.; Sætre, C.; Sansano Caramazana, A.; Sanz Arranz, A.; Sobron Grañón, F.; Veneranda, M.; Viennet, J.-C.; PTAL Team

2018-04-01

The Planetary Terrestrial Analogues Library project aims to build and exploit a spectral data base for the characterisation of the mineralogical and geological evolution of terrestrial planets and small solar system bodies.

Characterising invasive non-native Rhododendron ponticum spectra signatures with spectroradiometry in the laboratory and field: Potential for remote mapping

NASA Astrophysics Data System (ADS)

Taylor, Sarah L.; Hill, Ross A.; Edwards, Colin

2013-07-01

Compared with traditional ground surveys, remote sensing has the potential to map the spatial extent of non-native invasive species rapidly and reliably. This paper assesses the potential of spectroradiometry to distinguish and characterise the status of invasive non-native rhododendron (Rhododendron ponticum). Absolute reflectance of target plant material was measured with an ASD Fieldspec Pro System under standardised laboratory conditions and in the field to characterise spectral signatures in the winter, during leaf-off conditions for woodland overstory, and in the summer when mature rhododendrons are flowering. A logistic regression model of absolute reflectance at key wavelengths (490, 550, 610, 1040 and 1490 nm) was used to determine the success of discriminating rhododendron from three other shrubby species likely to be encountered in woodlands during the winter. The logistic regression model was highly significant (p < 0.001), with 93.5% of 246 leaf sets correctly identified as rhododendron or non-rhododendron (i.e. cherry laurel (Prunus laurocerasus), holly (Ilex aquifolium), and beech (Fagus sylvatica)). Rescaling the data to emulate the spectral resolution of airborne and satellite acquired data decreased the total success rate of correctly identifying rhododendron by only 0.4%; although this error rate will likely increase for airborne or satellite data as a result of atmospheric attenuation and reduced spatial resolution. This demonstrates the potential to map bush presence using hyperspectral data and indicates the optimum spectral wavelengths required. Such information is critical to the development of successful strategic management plans to eradicate rhododendron (and the associated Phytophthora ramorum pathogen) effectively from a site.

Beyond NIMBYs and NOOMBYs: what can wind farm controversies teach us about public involvement in hospital closures?

PubMed

Stewart, Ellen; Aitken, Mhairi

2015-12-01

Many policymakers, researchers and commentators argue that hospital closures are necessary as health systems adapt to new technological and financial contexts, and as population health needs in developed countries shift. However closures are often unpopular with local communities. Previous research has characterised public opposition as an obstacle to change. Public opposition to the siting of wind farms, often described as NIMBYism (Not In My Back Yard), is a useful comparator issue to the perceived NOOMBYism (Not Out Of My Back Yard) of hospital closure protestors. The analysis of public attitudes to wind farms has moved from a fairly crude characterisation of the 'attitude-behaviour gap' between publics who support the idea of wind energy, but oppose local wind farms, to empirical, often qualitative, studies of public perspectives. These have emphasised the complexity of public attitudes, and revealed some of the 'rational' concerns which lie beneath protests. Research has also explored processes of community engagement within the wind farm decision-making process, and the crucial role of trust between communities, authorities, and developers. Drawing on what has been learnt from studies of opposition to wind farms, we suggest a range of questions and approaches to explore public perspectives on hospital closure more thoroughly. Understanding the range of public responses to service change is an important first step in resolving the practical dilemma of effecting health system transformation in a democratic fashion.

Mobility of engineered inorganic nanoparticles in porous media

NASA Astrophysics Data System (ADS)

Metreveli, George; Heidmann, Ilona; Schaumann, Gabriele Ellen

2013-04-01

Besides the excellent properties and great potential for various industrial, medical, pharmaceutical, cosmetic, and life science applications, engineered inorganic nanoparticles (EINP) can show also disadvantages concerning increasing risk potential with increasing application, if they are released in the environmental systems. EINP can influence microbial activity and can show toxic effects (Fabrega et al., 2009). Similar to the inorganic natural colloids, EINP can be transported in soil and groundwater systems (Metreveli et al., 2005). Furthermore, due to the large surface area and high sorption and complex formation capacity, EINP can facilitate transport of different contaminants. In this study the mobility behaviour of EINP and their effect on the transport of different metal(loid) species in water saturated porous media was investigated. For these experiments laboratory column system was used. The column was filled with quartz sand. The interactions between EINP and metal(loid)s were characterised by coupling of asymmetrical flow field flow fractionation (AF4) with inductively coupled plasma mass spectrometer (ICP-MS). As EINP laponite (synthetic three layer clay mineral), and as metal(loid)s Cu, Pb, Zn, Pt and As were used. In AF4 experiments sorption of metal(loid)s on the surface of EINP could be observed. The extent of interactions was influenced by pH value and was different for different metal(loid)s. Laboratory column experiments showed high mobility of EINP, which facilitated transport of most of metal(loid)s in water saturated porous media. Furthermore the migration of synthetic silver nanoparticles in natural soil columns was determined in leaching experiments. Acknowledgement Financial support by German Research Council (DFG) and Max-Buchner-Research Foundation (MBFSt) is gratefully acknowledged. We thank Karlsruhe Institute of Technology (KIT) for the opportunity to perform the column and AF4 experiments. References: Fabrega, J., Fawcett, S. R., Renshaw, J. C. Lead, J. R. 2009. Silver nanoparticle impact on bacterial growth: Effect of pH, concentration, and organic matter. Environ. Sci. Technol. 43 (19): 7285-7290 Metreveli, G., Kaulisch, E.-M., Frimmel, F. H. 2005. Coupling of a column system with ICP-MS for the characterisation of colloid mediated metal(loid) transport in porous media. Acta Hydrochim. Hydrobiol. 33 (4): 337-345

The Heroic and the Villainous: a qualitative study characterising the role models that shaped senior doctors' professional identity.

PubMed

Foster, Kirsty; Roberts, Chris

2016-08-16

The successful development and sustaining of professional identity is critical to being a successful doctor. This study explores the enduring impact of significant early role models on the professional identity formation of senior doctors. Personal Interview Narratives were derived from the stories told by twelve senior doctors as they recalled accounts of people and events from the past that shaped their notions of being a doctor. Narrative inquiry methodology was used to explore and analyse video recording and transcript data from interviews. Role models were frequently characterised as heroic, or villainous depending on whether they were perceived as good or bad influences respectively. The degree of sophistication in participants' characterisations appeared to correspond with the stage of life of the participant at the time of the encounter. Heroes were characterised as attractive, altruistic, caring and clever, often in exaggerated terms. Conversely, villains were typically characterised as direct or covert bullies. Everyday events were surprisingly powerful, emotionally charged and persisted in participants' memories much longer than expected. In particular, unresolved emotions dating from encounters where bullying behaviour had been witnessed or experienced were still apparent decades after the event. The characterisation of role models is an important part of the professional identity and socialisation of senior doctors. The enduring impact of what role models say and do means that all doctors, need to consistently reflect on how their own behaviour impacts the development of appropriate professional behaviours in both students and training doctors. This is especially important where problematic behaviours occur as, if not dealt with, they have the potential for long-lasting undesirable effects. The importance of small acts of caring in building a nurturing and supportive learning atmosphere at all stages of medical education cannot be underestimated.

Some Aspects of Computer-Supported Teaching When Teaching Bachelors

ERIC Educational Resources Information Center

Svetsky, Stefan; Moravcik, Oliver; Schreiber, Peter; Stefankova, Jana

2013-01-01

The state of the art of TEL (technology-enhanced learning) is characterised by a technological-driven approach. Learning management systems or learning courses for management systems are mentioned as frequently used basic tools for this purpose. However, these Internet technologies are not suitable for the personalized support of teachers on…

Large-Scale Implementation of Formative Assessment Practices in an Examination-Oriented Culture

ERIC Educational Resources Information Center

Ratnam-Lim, Christina Tong Li; Tan, Kelvin Heng Kiat

2015-01-01

Singapore's education system has often been characterised as exam-oriented. This paper describes efforts ("windmills") made by the Government to constructively respond to the "winds of change" in the education system. A committee called the Primary Education Review and Implementation (PERI) Committee was appointed to study and…

Quantifying the increasing sensitivity of power systems to climate variability

NASA Astrophysics Data System (ADS)

Bloomfield, H. C.; Brayshaw, D. J.; Shaffrey, L. C.; Coker, P. J.; Thornton, H. E.

2016-12-01

Large quantities of weather-dependent renewable energy generation are expected in power systems under climate change mitigation policies, yet little attention has been given to the impact of long term climate variability. By combining state-of-the-art multi-decadal meteorological records with a parsimonious representation of a power system, this study characterises the impact of year-to-year climate variability on multiple aspects of the power system of Great Britain (including coal, gas and nuclear generation), demonstrating why multi-decadal approaches are necessary. All aspects of the example system are impacted by inter-annual climate variability, with the impacts being most pronounced for baseload generation. The impacts of inter-annual climate variability increase in a 2025 wind-power scenario, with a 4-fold increase in the inter-annual range of operating hours for baseload such as nuclear. The impacts on peak load and peaking-plant are comparably small. Less than 10 years of power supply and demand data are shown to be insufficient for providing robust power system planning guidance. This suggests renewable integration studies—widely used in policy, investment and system design—should adopt a more robust approach to climate characterisation.

Physico-chemical characterisation of material fractions in household waste: Overview of data in literature.

PubMed

Götze, Ramona; Boldrin, Alessio; Scheutz, Charlotte; Astrup, Thomas Fruergaard

2016-03-01

State-of-the-art environmental assessment of waste management systems rely on data for the physico-chemical composition of individual material fractions comprising the waste in question. To derive the necessary inventory data for different scopes and systems, literature data from different sources and backgrounds are consulted and combined. This study provides an overview of physico-chemical waste characterisation data for individual waste material fractions available in literature and thereby aims to support the selection of data fitting to a specific scope and the selection of uncertainty ranges related to the data selection from literature. Overall, 97 publications were reviewed with respect to employed characterisation method, regional origin of the waste, number of investigated parameters and material fractions and other qualitative aspects. Descriptive statistical analysis of the reported physico-chemical waste composition data was performed to derive value ranges and data distributions for element concentrations (e.g. Cd content) and physical parameters (e.g. heating value). Based on 11,886 individual data entries, median values and percentiles for 47 parameters in 11 individual waste fractions are presented. Exceptional values and publications are identified and discussed. Detailed datasets are attached to this study, allowing further analysis and new applications of the data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rational design of a dual-mode optical and chemical prodrug.

PubMed

McCoy, Colin P; Rooney, Clare; Jones, David S; Gorman, Sean P; Nieuwenhuyzen, Mark

2007-01-01

The purpose of this study is to demonstrate the rational design and behaviour of the first dual-mode optical and chemical prodrug, exemplified by an acetyl salicylic acid-based system. A cyclic 1,4-benzodioxinone prodrug was synthesised by reaction of 3,5-dimethoxybenzoin and acetyl salicoyl chloride with pyridine. After purification by column chromatography and recrystallization, characterization was achieved using infrared and NMR spectroscopies, mass spectrometry, elemental analysis and single crystal X-ray diffraction. Light-triggered drug liberation was characterised via UV-visible spectroscopy following low-power 365 nm irradiation for controlled times. Chemical drug liberation was characterised via UV-visible spectroscopy in pH 5.5 solution. The synthetic method yielded pure prodrug, with full supporting characterisation. Light-triggered drug liberation proceeded at a rate of 8.30x10(-2) s-1, while chemical, hydrolytic liberation proceeded independently at 1.89x10(-3) s-1. The photochemical and hydrolytic reactions were both quantitative. This study demonstrates the first rational dual-mode optical and chemical prodrug, using acetyl salicylic acid as a model, acting as a paradigm for future dual-mode systems. Photochemical drug liberation proceeds 44 times faster than chemical liberation, suggesting potential use in drug-eluting medical devices where an additional burst of drug is required at the onset of infection.

Tinnitus: considerations for nursing practice.

PubMed

Truscott, Gill

2016-11-09

Tinnitus is a common condition characterised by a subjective, and less commonly objective, noise sensation that is often described as ringing heard in one or both ears by the individual. The exact cause of tinnitus is not known, but it is related to physiological changes in the auditory system and is closely linked to psychological well-being. Tinnitus can have a significant effect on the lives of people who experience it on a continuous basis. Although there is no cure for tinnitus, various strategies are available to support individuals to manage the condition on a daily basis; these management strategies are discussed in this article.

Generic instabilities in a fluid membrane coupled to a thin layer of ordered active polar fluid.

PubMed

Sarkar, Niladri; Basu, Abhik

2013-08-01

We develop an effective two-dimensional coarse-grained description for the coupled system of a planar fluid membrane anchored to a thin layer of polar ordered active fluid below. The macroscopic orientation of the active fluid layer is assumed to be perpendicular to the attached membrane. We demonstrate that activity or nonequilibrium drive of the active fluid makes such a system generically linearly unstable for either signature of a model parameter [Formula: see text] [Formula: see text] that characterises the strength of activity. Depending upon boundary conditions and within a range of the model parameters, underdamped propagating waves may be present in our model. We discuss the phenomenological significance of our results.

Fault detection for discrete-time LPV systems using interval observers

NASA Astrophysics Data System (ADS)

Zhang, Zhi-Hui; Yang, Guang-Hong

2017-10-01

This paper is concerned with the fault detection (FD) problem for discrete-time linear parameter-varying systems subject to bounded disturbances. A parameter-dependent FD interval observer is designed based on parameter-dependent Lyapunov and slack matrices. The design method is presented by translating the parameter-dependent linear matrix inequalities (LMIs) into finite ones. In contrast to the existing results based on parameter-independent and diagonal Lyapunov matrices, the derived disturbance attenuation, fault sensitivity and nonnegative conditions lead to less conservative LMI characterisations. Furthermore, without the need to design the residual evaluation functions and thresholds, the residual intervals generated by the interval observers are used directly for FD decision. Finally, simulation results are presented for showing the effectiveness and superiority of the proposed method.

Health effects of residential wood smoke particles: the importance of combustion conditions and physicochemical particle properties

PubMed Central

Kocbach Bølling, Anette; Pagels, Joakim; Yttri, Karl Espen; Barregard, Lars; Sallsten, Gerd; Schwarze, Per E; Boman, Christoffer

2009-01-01

Background Residential wood combustion is now recognized as a major particle source in many developed countries, and the number of studies investigating the negative health effects associated with wood smoke exposure is currently increasing. The combustion appliances in use today provide highly variable combustion conditions resulting in large variations in the physicochemical characteristics of the emitted particles. These differences in physicochemical properties are likely to influence the biological effects induced by the wood smoke particles. Outline The focus of this review is to discuss the present knowledge on physicochemical properties of wood smoke particles from different combustion conditions in relation to wood smoke-induced health effects. In addition, the human wood smoke exposure in developed countries is explored in order to identify the particle characteristics that are relevant for experimental studies of wood smoke-induced health effects. Finally, recent experimental studies regarding wood smoke exposure are discussed with respect to the applied combustion conditions and particle properties. Conclusion Overall, the reviewed literature regarding the physicochemical properties of wood smoke particles provides a relatively clear picture of how these properties vary with the combustion conditions, whereas particle emissions from specific classes of combustion appliances are less well characterised. The major gaps in knowledge concern; (i) characterisation of the atmospheric transformations of wood smoke particles, (ii) characterisation of the physicochemical properties of wood smoke particles in ambient and indoor environments, and (iii) identification of the physicochemical properties that influence the biological effects of wood smoke particles. PMID:19891791

Rigorous vector wave propagation for arbitrary flat media

NASA Astrophysics Data System (ADS)

Bos, Steven P.; Haffert, Sebastiaan Y.; Keller, Christoph U.

2017-08-01

Precise modelling of the (off-axis) point spread function (PSF) to identify geometrical and polarization aberrations is important for many optical systems. In order to characterise the PSF of the system in all Stokes parameters, an end-to-end simulation of the system has to be performed in which Maxwell's equations are rigorously solved. We present the first results of a python code that we are developing to perform multiscale end-to-end wave propagation simulations that include all relevant physics. Currently we can handle plane-parallel near- and far-field vector diffraction effects of propagating waves in homogeneous isotropic and anisotropic materials, refraction and reflection of flat parallel surfaces, interference effects in thin films and unpolarized light. We show that the code has a numerical precision on the order of 10-16 for non-absorbing isotropic and anisotropic materials. For absorbing materials the precision is on the order of 10-8. The capabilities of the code are demonstrated by simulating a converging beam reflecting from a flat aluminium mirror at normal incidence.

Ebola haemorrhagic fever

PubMed Central

Feldmann, Heinz; Geisbert, Thomas W

2012-01-01

Ebola viruses are the causative agents of a severe form of viral haemorrhagic fever in man, designated Ebola haemorrhagic fever, and are endemic in regions of central Africa. The exception is the species Reston Ebola virus, which has not been associated with human disease and is found in the Philippines. Ebola virus constitutes an important local public health threat in Africa, with a worldwide effect through imported infections and through the fear of misuse for biological terrorism. Ebola virus is thought to also have a detrimental effect on the great ape population in Africa. Case-fatality rates of the African species in man are as high as 90%, with no prophylaxis or treatment available. Ebola virus infections are characterised by immune suppression and a systemic inflammatory response that causes impairment of the vascular, coagulation, and immune systems, leading to multiorgan failure and shock, and thus, in some ways, resembling septic shock. PMID:21084112

Critiquing Neoliberalism in Australian Universities

ERIC Educational Resources Information Center

Rea, Jeannie

2016-01-01

While students chanting "No cuts, No fees, No corporate universities" may be dismissed as youthful hyperbole by some, it is not as superficial a characterisation of the state of our public university system as it seems.

Application of nanoparticle tracking analysis for characterising the fate of engineered nanoparticles in sediment-water systems.

PubMed

Luo, Ping; Roca, Alejandro; Tiede, Karen; Privett, Katie; Jiang, Jiachao; Pinkstone, John; Ma, Guibin; Veinot, Jonathan; Boxall, Alisatair

2018-02-01

Novel applications of nanotechnology may lead to the release of engineered nanoparticles (ENPs), which result in concerns over their potential environmental hazardous impact. It is essential for the research workers to be able to quantitatively characterise ENPs in the environment and subsequently to assist the risk assessment of the ENPs. This study hence explored the application of nanoparticle tracking system (NTA) to quantitatively describe the behaviour of the ENPs in natural sediment-water systems. The NTA allows the measurement of both particle number concentration (PNC) and particle size distribution (PSD) of the ENPs. The developed NTA method was applied to a range of gold and magnetite ENPs with a selection of surface properties. The results showed that the positively-charged ENPs interacted more strongly with the sediment than neutral and negatively-charged ENPs. It was also found that the citrate coated Au ENPs had a higher distribution percentage (53%) than 11-mercaptoundecanoic acid coated Au ENPs (20%) and citrate coated magnetite ENPs (21%). The principles of the electrostatic interactions between hard (and soft) acids and bases (HSAB) are used to explain such behaviours; the hard base coating (i.e. citrate ions) will interact more strongly with hard acid (i.e. magnetite) than soft acid (i.e. gold). The results indicate that NTA is a complementary method to existing approaches to characterise the fate and behaviour of ENPs in natural sediment. Copyright © 2017. Published by Elsevier B.V.

Drought characterisation based on an agriculture-oriented standardised precipitation index

NASA Astrophysics Data System (ADS)

Tigkas, Dimitris; Vangelis, Harris; Tsakiris, George

2018-03-01

Drought is a major natural hazard with significant effects in the agricultural sector, especially in arid and semi-arid regions. The accurate and timely characterisation of agricultural drought is crucial for devising contingency plans, including the necessary mitigation measures. Many drought indices have been developed during the last decades for drought characterisation and analysis. One of the most widely used indices worldwide is the Standardised Precipitation Index (SPI). Although other comprehensive indices have been introduced over the years, SPI remains the most broadly accepted index due to a number of reasons, the most important of which are its simple structure and the fact that it uses only precipitation data. In this paper, a modified version of SPI is proposed, namely the Agricultural Standardised Precipitation Index (aSPI), based on the substitution of the total precipitation by the effective precipitation, which describes more accurately the amount of water that can be used productively by the plants. Further, the selection of the most suitable reference periods and time steps for agricultural drought identification using aSPI is discussed. This conceptual enhancement of SPI aims at improving the suitability of the index for agricultural drought characterisation, while retaining the advantages of the original index, including its dependence only on precipitation data. The evaluation of the performance of both SPI and aSPI in terms of correlating drought magnitude with crop yield response in four regions of Greece under Mediterranean conditions indicated that aSPI is more robust than the original index in identifying agricultural drought.

Geophysical characterisation of the groundwater-surface water interface

NASA Astrophysics Data System (ADS)

McLachlan, P. J.; Chambers, J. E.; Uhlemann, S. S.; Binley, A.

2017-11-01

Interactions between groundwater (GW) and surface water (SW) have important implications for water quantity, water quality, and ecological health. The subsurface region proximal to SW bodies, the GW-SW interface, is crucial as it actively regulates the transfer of nutrients, contaminants, and water between GW systems and SW environments. However, geological, hydrological, and biogeochemical heterogeneity in the GW-SW interface makes it difficult to characterise with direct observations. Over the past two decades geophysics has been increasingly used to characterise spatial and temporal variability throughout the GW-SW interface. Geophysics is a powerful tool in evaluating structural heterogeneity, revealing zones of GW discharge, and monitoring hydrological processes. Geophysics should be used alongside traditional hydrological and biogeochemical methods to provide additional information about the subsurface. Further integration of commonly used geophysical techniques, and adoption of emerging techniques, has the potential to improve understanding of the properties and processes of the GW-SW interface, and ultimately the implications for water quality and environmental health.

Transesterification of PHA to oligomers covalently bonded with (bio)active compounds containing either carboxyl or hydroxyl functionalities.

PubMed

Kwiecień, Iwona; Radecka, Iza; Kowalczuk, Marek; Adamus, Grażyna

2015-01-01

This manuscript presents the synthesis and structural characterisation of novel biodegradable polymeric controlled-release systems of pesticides with potentially higher resistance to weather conditions in comparison to conventional forms of pesticides. Two methods for the preparation of pesticide-oligomer conjugates using the transesterification reaction were developed. The first method of obtaining conjugates, which consist of bioactive compounds with the carboxyl group and polyhydroxyalkanoates (PHAs) oligomers, is "one-pot" transesterification. In the second method, conjugates of bioactive compounds with hydroxyl group and polyhydroxyalkanoates oligomers were obtained in two-step method, through cyclic poly(3-hydroxybutyrate) oligomers. The obtained pesticide-PHA conjugates were comprehensively characterised using GPC, 1H NMR and mass spectrometry techniques. The structural characterisation of the obtained products at the molecular level with the aid of mass spectrometry confirmed that both of the synthetic strategies employed led to the formation of conjugates in which selected pesticides were covalently bonded to PHA oligomers via a hydrolysable ester bond.

Health risks of climate change: an assessment of uncertainties and its implications for adaptation policies.

PubMed

Wardekker, J Arjan; de Jong, Arie; van Bree, Leendert; Turkenburg, Wim C; van der Sluijs, Jeroen P

2012-09-19

Projections of health risks of climate change are surrounded with uncertainties in knowledge. Understanding of these uncertainties will help the selection of appropriate adaptation policies. We made an inventory of conceivable health impacts of climate change, explored the type and level of uncertainty for each impact, and discussed its implications for adaptation policy. A questionnaire-based expert elicitation was performed using an ordinal scoring scale. Experts were asked to indicate the level of precision with which health risks can be estimated, given the present state of knowledge. We assessed the individual scores, the expertise-weighted descriptive statistics, and the argumentation given for each score. Suggestions were made for how dealing with uncertainties could be taken into account in climate change adaptation policy strategies. The results showed that the direction of change could be indicated for most anticipated health effects. For several potential effects, too little knowledge exists to indicate whether any impact will occur, or whether the impact will be positive or negative. For several effects, rough 'order-of-magnitude' estimates were considered possible. Factors limiting health impact quantification include: lack of data, multi-causality, unknown impacts considering a high-quality health system, complex cause-effect relations leading to multi-directional impacts, possible changes of present-day response-relations, and difficulties in predicting local climate impacts. Participants considered heat-related mortality and non-endemic vector-borne diseases particularly relevant for climate change adaptation. For possible climate related health impacts characterised by ignorance, adaptation policies that focus on enhancing the health system's and society's capability of dealing with possible future changes, uncertainties and surprises (e.g. through resilience, flexibility, and adaptive capacity) are most appropriate. For climate related health effects for which rough risk estimates are available, 'robust decision-making' is recommended. For health effects with limited societal and policy relevance, we recommend focusing on no-regret measures. For highly relevant health effects, precautionary measures can be considered. This study indicated that analysing and characterising uncertainty by means of a typology can be a very useful approach for selection and prioritization of preferred adaptation policies to reduce future climate related health risks.

Proportional-delayed controllers design for LTI-systems: a geometric approach

NASA Astrophysics Data System (ADS)

Hernández-Díez, J.-E.; Méndez-Barrios, C.-F.; Mondié, S.; Niculescu, S.-I.; González-Galván, E. J.

2018-04-01

This paper focuses on the design of P-δ controllers for single-input-single-output linear time-invariant systems. The basis of this work is a geometric approach allowing to partitioning the parameter space in regions with constant number of unstable roots. This methodology defines the hyper-planes separating the aforementioned regions and characterises the way in which the number of unstable roots changes when crossing such a hyper-plane. The main contribution of the paper is that it provides an explicit tool to find P-δ gains ensuring the stability of the closed-loop system. In addition, the proposed methodology allows to design a non-fragile controller with a desired exponential decay rate σ. Several numerical examples illustrate the results and a haptic experimental set-up shows the effectiveness of P-δ controllers.

Modelling, analysis and validation of microwave techniques for the characterisation of metallic nanoparticles

NASA Astrophysics Data System (ADS)

Sulaimalebbe, Aslam

In the last decade, the study of nanoparticle (NP) systems has become a large and interesting research area due to their novel properties and functionalities, which are different from those of the bulk materials, and also their potential applications in different fields. It is vital to understand the behaviour and properties of nano-materials aiming at implementing nanotechnology, controlling their behaviour and designing new material systems with superior performance. Physical characterisation of NPs falls into two main categories, property and structure analysis, where the properties of the NPs cannot be studied without the knowledge of size and structure. The direct measurement of the electrical properties of metal NPs presents a key challenge and necessitates the use of innovative experimental techniques. There have been numerous reports of two/four point resistance measurements of NPs films and also electrical conductivity of NPs films using the interdigitated microarray (IDA) electrode. However, using microwave techniques such as open ended coaxial probe (OCP) and microwave dielectric resonator (DR) for electrical characterisation of metallic NPs are much more accurate and effective compared to other traditional techniques. This is because they are inexpensive, convenient, non-destructive, contactless, hazardless (i.e. at low power) and require no special sample preparation. This research is the first attempt to determine the microwave properties of Pt and Au NP films, which were appealing materials for nano-scale electronics, using the aforementioned microwave techniques. The ease of synthesis, relatively cheap, unique catalytic activities and control over the size and the shape were the main considerations in choosing Pt and Au NPs for the present study. The initial phase of this research was to implement and validate the aperture admittance model for the OCP measurement through experiments and 3D full wave simulation using the commercially available Ansoft High Frequency Structure Simulator (HFSS), followed by the electrical characterisation of synthesised Pt NP films using the novel miniature fabricated OCP technique. The results obtained from this technique provided the inspiration to synthesise and evaluate the microwave properties of Au NPs. The findings from this technique provided the motivation to characterise both the Pt and Au NP films using the DR technique. Unlike the OCP technique, the DR method is highly sensitive but the achievable measurement accuracy is limited since this technique does not have broadband frequency capability like the OCP method. The results obtained from the DR technique show a good agreement with the theoretical prediction. In the last phase of this research, a further validation of the aperture admittance models on different types OCP (i.e. RG-405 and RG-402 cables and SMA connector) have been carried out on the developed 3D full wave models using HFSS software, followed by the development of universal models for the aforementioned OCPs based on the same 3D full wave models.

High-throughput SRCD using multi-well plates and its applications

NASA Astrophysics Data System (ADS)

Hussain, Rohanah; Jávorfi, Tamás; Rudd, Timothy R.; Siligardi, Giuliano

2016-12-01

The sample compartment for high-throughput synchrotron radiation circular dichroism (HT-SRCD) has been developed to satisfy an increased demand of protein characterisation in terms of folding and binding interaction properties not only in the traditional field of structural biology but also in the growing research area of material science with the potential to save time by 80%. As the understanding of protein behaviour in different solvent environments has increased dramatically the development of novel functions such as recombinant proteins modified to have different functions from harvesting solar energy to metabolonics for cleaning heavy and metal and organic molecule pollutions, there is a need to characterise speedily these system.

Competition, Autonomy and New Thinking: Transformation of Higher Education in Federal Germany

ERIC Educational Resources Information Center

Mayer, Peter; Ziegele, Frank

2009-01-01

Germany has recently gone through a fundamental process of reform of its higher education system. The last 15 years have been characterised by significant changes in virtually all aspects of the system. The impacts of the Bologna Process have been far reaching. The reform of the governance and funding systems in higher education has also been…

International Education Policy: Its Influence on the Conception of VET and the VET System in Germany

ERIC Educational Resources Information Center

Deissinger, Thomas

2015-01-01

Inquiries into vocational education and training (VET) systems are normally characterised by looking at institutions and steering mechanisms. That aside, however, it is culture which underlies both the practice and the theory as well as the policy of VET in various countries. Specific problems arise when it comes to harmonising VET systems through…

Washing away your sins will set your mind free: physical cleansing modulates the effect of threatened morality on executive control.

PubMed

Kalanthroff, Eyal; Aslan, Chen; Dar, Reuven

2017-01-01

The effect of threatened morality on negative emotions and on altruistic behaviour has been shown to diminish following physical cleansing (hand-washing). We hypothesised that threatened morality will broadly impair the executive control system, and that physical cleansing will moderate this detrimental effect. Thirty-seven participants were asked to write about an immoral deed they had committed, whereupon half of them were allowed to wipe their hands. Three executive control tasks-Stroop, stop-signal, and object interference-were then administered to all participants. Participants who had not wiped their hands, but not those who did, demonstrated impaired performance, compared to hand-washing controls, in all three tasks. We conclude that threatened morality has a detrimental effect on executive control, specifically on conflict monitoring and response inhibition, and that physical cleansing "frees" this system, counteracting the detrimental effects of morality threats. We discuss possible implications for obsessive-compulsive disorder, which is characterised by deficient executive control and in which both threatened morality and physical cleansing are central concerns.

Characterisation of swabbing for virological analysis in the Spanish Influenza Sentinel Surveillance System during four influenza seasons in the period 2002-2006.

PubMed

Larrauri, A; de Mateo, S

2007-05-01

This study sought to characterise the swabbing pattern in the Spanish Influenza Sentinel Surveillance System (SISSS) and ascertain to what extent the system meets the guidelines currently being drafted by The European Influenza Surveillance Scheme (EISS). Data on seasons 2002/2003 to 2005/2006 were drawn from SISSS. The study analysed collection and dispatch of swab specimens for virological analysis by reference to variables relating to patient sex, age group, vaccination status, specimen collection period, period of influenza activity, time of swabbing and epidemiological season. SISSS adapts to EISS recommendations with respect to the specimen collection period and period of influenza activity, but there is a tendency to collect fewer specimens than recommended as the age of patients increases, and in the case of elderly patients (65 years and older), frequency of collection is clearly insufficient. Furthermore, sentinel physicians collect a higher percentage of specimens in cases where patients have received the influenza vaccine.

Mechanical characterisation of agarose-based chromatography resins for biopharmaceutical manufacture.

PubMed

Nweke, Mauryn C; McCartney, R Graham; Bracewell, Daniel G

2017-12-29

Mechanical characterisation of agarose-based resins is an important factor in ensuring robust chromatographic performance in the manufacture of biopharmaceuticals. Pressure-flow profiles are most commonly used to characterise these properties. There are a number of drawbacks with this method, including the potential need for several re-packs to achieve the desired packing quality, the impact of wall effects on experimental set up and the quantities of chromatography media and buffers required. To address these issues, we have developed a dynamic mechanical analysis (DMA) technique that characterises the mechanical properties of resins based on the viscoelasticity of a 1ml sample of slurry. This technique was conducted on seven resins with varying degrees of mechanical robustness and the results were compared to pressure-flow test results on the same resins. Results show a strong correlation between the two techniques. The most mechanically robust resin (Capto Q) had a critical velocity 3.3 times higher than the weakest (Sepharose CL-4B), whilst the DMA technique showed Capto Q to have a slurry deformation rate 8.3 times lower than Sepharose CL-4B. To ascertain whether polymer structure is indicative of mechanical strength, scanning electron microscopy images were also used to study the structural properties of each resin. Results indicate that DMA can be used as a small volume, complementary technique for the mechanical characterisation of chromatography media. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy

NASA Astrophysics Data System (ADS)

Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.

2015-04-01

The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping to make the focus of future study. The next stage of this work will be to develop conceptual models of the thermal groundwater regime, and monitoring under abstraction conditions to confirm the sustainability of groundwater temperatures as a long-term thermal resource. We have also instrumented a non-infiltration Sustainable Urban Drainage System (SuDS) scheme, where we will characterise the effect upon the thermal groundwater resource as localised infiltration is reduced.

Rapid characterisation and identification of compounds in Saposhnikoviae Radix by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry.

PubMed

Chen, Luxiao; Chen, Xiangyang; Su, Lei; Jiang, Yanyan; Liu, Bin

2018-04-01

Saposhnikoviae Radix (SR), the dried root of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae), is commonly used as a traditional Chinese medicine. In this study, a rapid and accurate method was firstly, developed for the qualitative analysis of SR by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF-MS/MS). A total of 45 compounds were identified or tentatively characterised, including 13 chromones, 28 coumarins and four others. Among them, 16 compounds were identified from SR for the first time. In addition, six chromones reference standards, including two isolated compounds of 3'-O-angeloylhamaudol and norcimifugin from the extraction of SR, were used to study the fragmentation pathways of chromones. The developed method was effective for characterising the compounds of SR, and the results of the study enriched the understanding of the chemical connotation.

Underwater characterization of control rods for waste disposal using SMOPY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gallozzi-Ulmann, A.; Couturier, P.; Amgarou, K.

Storage of spent fuel assemblies in cooling ponds requires careful control of the geometry and proximity of adjacent assemblies. Measurement of the fuel burnup makes it possible to optimise the storage arrangement of assemblies taking into account the effect of the burnup on the criticality safety margins ('burnup credit'). Canberra has developed a measurement system for underwater measurement of spent fuel assemblies. This system, known as 'SMOPY', performs burnup measurements based on gamma spectroscopy (collimated CZT detector) and neutron counting (fission chamber). The SMOPY system offers a robust and waterproof detection system as well as the needed capability of performingmore » radiometric measurements in the harsh high dose - rate environments of the cooling ponds. The gamma spectroscopy functionality allows powerful characterization measurements to be performed, in addition to burnup measurement. Canberra has recently performed waste characterisation measurements at a Nuclear Power Plant. Waste activity assessment is important to control costs and risks of shipment and storage, to ensure that the activity level remains in the range allowed by the facility, and to declare activity data to authorities. This paper describes the methodology used for the SMOPY measurements and some preliminary results of a radiological characterisation of AIC control rods. After describing the features and normal operation of the SMOPY system, we describe the approach used for establishing an optimum control rod geometric scanning approach (optimum count time and speed) and the method of the gamma spectrometry measurements as well as neutron check measurements used to verify the absence of neutron sources in the waste. We discuss the results obtained including {sup 60}Co, {sup 110m}Ag and {sup 108m}Ag activity profiles (along the length of the control rods) and neutron results including Total Measurement Uncertainty evaluations. Full self-consistency checks were performed and these demonstrate the validity of the techniques. The results are described and analysed in the context of the measurement performance of the equipment. Different casks were fully characterized using a 60 mm{sup 3} CZT detector, to determine the total activities and spatial profiles. A total activity range measurement of 1x10{sup 8} - 1x10{sup 13} Bq/cm was found to be achievable. Finally, comments are made, based on our measurements, on the ability of this equipment for performing in-situ characterisation of wastes in the harsh environments typical of fuel assembly and waste storage ponds and silos. (authors)« less

Development of a digital video-microscopy technique to study lactose crystallisation kinetics in situ.

PubMed

Arellano, María Paz; Aguilera, José Miguel; Bouchon, Pedro

2004-11-15

Polarised light microscopy was employed non-invasively to monitor lactose crystallisation from non-seeded supersaturated solutions in real time. Images were continuously recorded, processed and characterised by image analysis, and the results were compared with those obtained by refractometry. Three crystallisation temperatures (10, 20 and 30 degrees C) and three different levels of initial relative supersaturation (C/C(s)=1.95; 2.34; 3.15) were investigated. Induction times using the imaging technique proved to be substantially lower than those determined using refractive index. Lactose crystals were isolated digitally to determine geometrical parameters of interest, such as perimeter, diameter, area, roundness and Feret mean, and to derive crystal growth rates. Mean growth rates obtained for single crystals were fitted to a combined mass transfer model (R(2)=0.9766). The model allowed the effects of temperature and supersaturation on crystallisation rate to be clearly identified. It also suggested that, in this set of experiments, surface integration seemed to be the rate controlling step. It is believed that a similar experimental set-up could be implemented in a real food system to characterise a particular process where crystallisation control is of interest and where traditional techniques are difficult to implement.

The therapeutic potential of G-protein coupled receptors in Huntington's disease.

PubMed

Dowie, Megan J; Scotter, Emma L; Molinari, Emanuela; Glass, Michelle

2010-11-01

Huntington's disease is a late-onset autosomal dominant inherited neurodegenerative disease characterised by increased symptom severity over time and ultimately premature death. An expanded CAG repeat sequence in the huntingtin gene leads to a polyglutamine expansion in the expressed protein, resulting in complex dysfunctions including cellular excitotoxicity and transcriptional dysregulation. Symptoms include cognitive deficits, psychiatric changes and a movement disorder often referred to as Huntington's chorea, which involves characteristic involuntary dance-like writhing movements. Neuropathologically Huntington's disease is characterised by neuronal dysfunction and death in the striatum and cortex with an overall decrease in cerebral volume (Ho et al., 2001). Neuronal dysfunction begins prior to symptom presentation, and cells of particular vulnerability include the striatal medium spiny neurons. Huntington's is a devastating disease for patients and their families and there is currently no cure, or even an effective therapy for disease symptoms. G-protein coupled receptors are the most abundant receptor type in the central nervous system and are linked to complex downstream pathways, manipulation of which may have therapeutic application in many neurological diseases. This review will highlight the potential of G-protein coupled receptor drug targets as emerging therapies for Huntington's disease. Copyright © 2010 Elsevier Inc. All rights reserved.

Application of multi-way analysis to UV-visible spectroscopy, gas chromatography and electronic nose data for wine ageing evaluation.

PubMed

Prieto, N; Rodriguez-Méndez, M L; Leardi, R; Oliveri, P; Hernando-Esquisabel, D; Iñiguez-Crespo, M; de Saja, J A

2012-03-16

In this study, a multi-way method (Tucker3) was applied to evaluate the performance of an electronic nose for following the ageing of red wines. The odour evaluation carried out with the electronic nose was combined with the quantitative analysis of volatile composition performed by GC-MS, and colour characterisation by UV-visible spectroscopy. Thanks to Tucker3, it was possible to understand connections among data obtained from these three different systems and to estimate the effect of different sources of variability on wine evaluation. In particular, the application of Tucker3 supplied a global visualisation of data structure, which was very informative to understand relationships between sensors responses and chemical composition of wines. The results obtained indicate that the analytical methods employed are useful tools to follow the wine ageing process, to differentiate wine samples according to ageing type (either in barrel or in stainless steel tanks with the addition of small oak wood pieces) and to the origin (French or American) of the oak wood. Finally, it was possible to designate the volatile compounds which play a major role in such a characterisation. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis and Characterisation of Biocompatible Polymer-Conjugated Magnetic Beads for Enhancement Stability of Urease.

PubMed

Doğaç, Yasemin Ispirli; Teke, Mustafa

2016-04-01

We reported natural polymer-conjugated magnetic featured urease systems for removal of urea effectively. The optimum temperature (20-60 °C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70 °C), pH stability (4.0-9.0), operational stability (0-250 min), reusability (18 times) and storage stability (24 weeks) were studied for characterisation of the urease-encapsulated biocompatible polymer-conjugated magnetic beads. Also, the surface groups and chemical structure of the magnetic beads were determined by using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The all urease-encapsulated magnetic beads protected their stability of 30-45 % relative activity at 70 °C. A significant increase was observed at their pH stability compared with the free urease for both acidic and alkaline medium. Besides this, their repeatability activity were approximately 100 % during 4(th) run. They showed residual activity of 50 % after 16 weeks. The importance of this work is enhancement stability of immobilised urease by biocompatible polymer-conjugated magnetic beads for the industrial application based on removal of urea.

Magnetic high throughput screening system for the development of nano-sized molecularly imprinted polymers for controlled delivery of curcumin.

PubMed

Piletska, Elena V; Abd, Bashar H; Krakowiak, Agata S; Parmar, Anitha; Pink, Demi L; Wall, Katie S; Wharton, Luke; Moczko, Ewa; Whitcombe, Michael J; Karim, Kal; Piletsky, Sergey A

2015-05-07

Curcumin is a versatile anti-inflammatory and anti-cancer agent known for its low bioavailability, which could be improved by developing materials capable of binding and releasing drug in a controlled fashion. The present study describes the preparation of magnetic nano-sized Molecularly Imprinted Polymers (nanoMIPs) for the controlled delivery of curcumin and their high throughput characterisation using microtitre plates modified with magnetic inserts. NanoMIPs were synthesised using functional monomers chosen with the aid of molecular modelling. The rate of release of curcumin from five polymers was studied under aqueous conditions and was found to correlate well with the binding energies obtained computationally. The presence of specific monomers was shown to be significant in ensuring effective binding of curcumin and to the rate of release obtained. Characterisation of the polymer particles was carried out using dynamic light scattering (DLS) technique and scanning electron microscopy (SEM) in order to establish the relationship between irradiation time and particle size. The protocols optimised during this study could be used as a blueprint for the development of nanoMIPs capable of the controlled release of potentially any compound of interest.

Embracing Connectedness and Change: A Complex Dynamic Systems Perspective for Applied Linguistic Research

ERIC Educational Resources Information Center

Cameron, Lynne

2015-01-01

Complex dynamic systems (CDS) theory offers a powerful metaphorical model of applied linguistic processes, allowing holistic descriptions of situated phenomena, and addressing the connectedness and change that often characterise issues in our field. A recent study of Kenyan conflict transformation illustrates application of a CDS perspective. Key…

School Principals' Agency as Reflected by Extracurricular Activities in the Israeli Education System

ERIC Educational Resources Information Center

Yemini, Miri; Addi-Raccah, Audrey

2013-01-01

This study examines the nature and extent of extracurricular activities in the Palestinian Arab, Jewish Religious and Jewish Secular educational sectors (Israeli education system also includes the Ultra-Orthodox sector with its own management, monitoring and governance apparatus.) in Israel, in order to characterise the contextual variables that…

The large-scale ionospheric transient current system response to upstream solar wind IMF Bz north-south and south-north turnings as seen by the WIND satellite and the full SuperMAG network of ground based magnetometers

NASA Astrophysics Data System (ADS)

Dods, Joe; Chapman, Sandra; Gjerloev, Jesper

2017-04-01

We characterise the response of the quiet-time (no substorms or storms) large scale ionospheric convection system to north-south and south-north IMF turnings by using a dynamical network of ground-based magnetometers. Canonical correlation between all pairs of SuperMAG magnetometer stations in the northern hemisphere (MLat 50-82°) is used to establish the extent of near-simultaneous magnetic response between regions of MLT-MLat. Parameters and maps that describe spatial-temporal correlation are used to characterise the system and its response to the turnings aggregated over several hundred events. We find that regions that experience large increases in correlation post-turning coincide with typical locations of a two cell convection system and are influenced by the IMF By. The time between the turnings reaching the magnetopause and a network response is found to be ˜8-10 minutes and correlation in the dayside occurs 2-8 mins before that in the nightside.

Forest Fire Finder - DOAS application to long-range forest fire detection

NASA Astrophysics Data System (ADS)

Valente de Almeida, Rui; Vieira, Pedro

2017-06-01

Fires are an important factor in shaping Earth's ecosystems. Plant and animal life, in almost every land habitat, are at least partially dependent on the effects of fire. However, their destructive force, which has often proven uncontrollable, is one of our greatest concerns, effectively resulting in several policies in the most important industrialised regions of the globe. This paper aims to comprehensively characterise the Forest Fire Finder (FFF), a forest fire detection system based mainly upon a spectroscopic technique called differential optical absorption spectroscopy (DOAS). The system is designed and configured with the goal of detecting higher-than-the-horizon smoke columns by measuring and comparing scattered sunlight spectra. The article covers hardware and software, as well as their interactions and specific algorithms for day mode operation. An analysis of data retrieved from several installations deployed in the course of the last 5 years is also presented. Finally, this paper features a discussion on the most prominent future improvements planned for the system, as well as its ramifications and adaptations, such as a thermal imaging system for short-range fire seeking or environmental quality control.

The effect of input DNA copy number on genotype call and characterising SNP markers in the humpback whale genome using a nanofluidic array.

PubMed

Bhat, Somanath; Polanowski, Andrea M; Double, Mike C; Jarman, Simon N; Emslie, Kerry R

2012-01-01

Recent advances in nanofluidic technologies have enabled the use of Integrated Fluidic Circuits (IFCs) for high-throughput Single Nucleotide Polymorphism (SNP) genotyping (GT). In this study, we implemented and validated a relatively low cost nanofluidic system for SNP-GT with and without Specific Target Amplification (STA). As proof of principle, we first validated the effect of input DNA copy number on genotype call rate using well characterised, digital PCR (dPCR) quantified human genomic DNA samples and then implemented the validated method to genotype 45 SNPs in the humpback whale, Megaptera novaeangliae, nuclear genome. When STA was not incorporated, for a homozygous human DNA sample, reaction chambers containing, on average 9 to 97 copies, showed 100% call rate and accuracy. Below 9 copies, the call rate decreased, and at one copy it was 40%. For a heterozygous human DNA sample, the call rate decreased from 100% to 21% when predicted copies per reaction chamber decreased from 38 copies to one copy. The tightness of genotype clusters on a scatter plot also decreased. In contrast, when the same samples were subjected to STA prior to genotyping a call rate and a call accuracy of 100% were achieved. Our results demonstrate that low input DNA copy number affects the quality of data generated, in particular for a heterozygous sample. Similar to human genomic DNA, a call rate and a call accuracy of 100% was achieved with whale genomic DNA samples following multiplex STA using either 15 or 45 SNP-GT assays. These calls were 100% concordant with their true genotypes determined by an independent method, suggesting that the nanofluidic system is a reliable platform for executing call rates with high accuracy and concordance in genomic sequences derived from biological tissue.

The effects of growth and collapse on the magmatic system below Mt Taranaki, New Zealand.

NASA Astrophysics Data System (ADS)

Procter, Jonathan; Marcroft, Grace; Zellmer, Georg; Zernack, Anke

2017-04-01

Mt. Taranaki exhibits one of the best long-term records of volcanic growth and destruction of any volcano worldwide, making it ideal for understanding the long-term effects of changing lithostatic pressure, or loading and unloading, on the magma chamber and magma supply. The ring-plain around Mt. Taranaki houses volcaniclastic deposits that provide a near continuous record of the evolution of the volcano, yet these records have remained relatively unexploited when investigating the interrelated cyclical phases of volcano collapse and growth, the geochemical evolution of the centre, and the consequent time-varying hazard potential. In this study, we systematically sampled pumice-rich tephra and pumice-rich mass flow deposits that were stratigraphically immediately before and after the 24,801 ± 268 years BP Pungarehu Formation debris avalanche ( 7.5 km3). Crystals (clinopyroxene and plagioclase) were characterised in detail. Mg and Fe zoning across selected crystals from samples pre-and post-debris avalanche were found to have completely equilibrated, yet zoning patterns in Al remained intact and showed major differences in their formation, allowing for the calculation of diffusion rates. These have enabled the determination of maximum residence times (depths and pressure regimes) of the magma system. It is intended that this technique will be applied across the stratigraphic record, which contains 14 collapse events. This will provide insights into crustal magma transport and residence times, and the propagation of fissures and the buoyancy of the magma pre- and post-collapse, in order to characterise the evolution of the centre and quantify the long-term relationship between magmatic rise and volcano growth and destruction.

Recent advances in Echinococcus genomics and stem cell research.

PubMed

Koziol, U; Brehm, K

2015-10-30

Alveolar and cystic echinococcosis, caused by the metacestode larval stages of the tapeworms Echinococcus multilocularis and Echinococcus granulosus, respectively, are life-threatening diseases and very difficult to treat. The introduction of benzimidazole-based chemotherapy, which targets parasite β-tubulin, has significantly improved the life-span and prognosis of echinococcosis patients. However, benzimidazoles show only parasitostatic activity, are associated with serious adverse side effects and have to be administered for very long time periods, underlining the need for new drugs. Very recently, the nuclear genomes of E. multilocularis and E. granulosus have been characterised, revealing a plethora of data for gaining a deeper understanding of host-parasite interaction, parasite development and parasite evolution. Combined with extensive transcriptome analyses of Echinococcus life cycle stages these investigations also yielded novel clues for targeted drug design. Recent years also witnessed significant advancements in the molecular and cellular characterisation of the Echinococcus 'germinative cell' population, which forms a unique stem cell system that differs from stem cells of other organisms in the expression of several genes associated with the maintenance of pluripotency. As the only parasite cell type capable of undergoing mitosis, the germinative cells are central to all developmental transitions of Echinococcus within the host and to parasite expansion via asexual proliferation. In the present article, we will briefly introduce and discuss recent advances in Echinococcus genomics and stem cell research in the context of drug design and development. Interestingly, it turns out that benzimidazoles seem to have very limited effects on Echinococcus germinative cells, which could explain the high recurrence rates observed after chemotherapeutic treatment of echinococcosis patients. This clearly indicates that future efforts into the development of parasitocidal drugs should also target the parasite's stem cell system. Copyright © 2015 Elsevier B.V. All rights reserved.

A "Do-It-Yourself" phenotyping system: measuring growth and morphology throughout the diel cycle in rosette shaped plants.

PubMed

Dobrescu, Andrei; Scorza, Livia C T; Tsaftaris, Sotirios A; McCormick, Alistair J

2017-01-01

Improvements in high-throughput phenotyping technologies are rapidly expanding the scope and capacity of plant biology studies to measure growth traits. Nevertheless, the costs of commercial phenotyping equipment and infrastructure remain prohibitively expensive for wide-scale uptake, while academic solutions can require significant local expertise. Here we present a low-cost methodology for plant biologists to build their own phenotyping system for quantifying growth rates and phenotypic characteristics of Arabidopsis thaliana rosettes throughout the diel cycle. We constructed an image capture system consisting of a near infra-red (NIR, 940 nm) LED panel with a mounted Raspberry Pi NoIR camera and developed a MatLab-based software module (iDIEL Plant) to characterise rosette expansion. Our software was able to accurately segment and characterise multiple rosettes within an image, regardless of plant arrangement or genotype, and batch process image sets. To further validate our system, wild-type Arabidopsis plants (Col-0) and two mutant lines with reduced Rubisco contents, pale leaves and slow growth phenotypes ( 1a3b and 1a2b ) were grown on a single plant tray. Plants were imaged from 9 to 24 days after germination every 20 min throughout the 24 h light-dark growth cycle (i.e. the diel cycle). The resulting dataset provided a dynamic and uninterrupted characterisation of differences in rosette growth and expansion rates over time for the three lines tested. Our methodology offers a straightforward solution for setting up automated, scalable and low-cost phenotyping facilities in a wide range of lab environments that could greatly increase the processing power and scalability of Arabidopsis soil growth experiments.

Biomimetic routes to nanoscale-toughened oxide ceramics

NASA Astrophysics Data System (ADS)

Deschaume, Olivier

In this work, a novel anion exchange technique has been developed and optimised in order to prepare extra-pure, hydroxide-free solutions of aluminium polyoxocations (A113 and A130) as well as for the preparation of nanosized, highly monodisperse aluminium hydroxide particles in the particle size range 20-200nm. In order for the evolution and composition of the resulting systems to be monitored, an array of characterisation techniques including 27A1 NMR, dynamic light scattering, po-tentiometry, conductometry and UV-Vis spectroscopy, have been implemented and complemented with successful data treatment strategies. The quantitative data obtained indicates that the static anion exchange method is a soft, environmentally friendly, low-cost, energy-saving and convenient procedure for the preparation of Al- containing model systems. The A1 species obtained can be used for high-precision model studies on A1 speciation, and serve as nanosize precursors to a variety of Al-containing materials. The use of these pure A1 precursors has a clear advantage in materials synthesis arising from an improved understanding and better control of A1 speciation. In a second development of the project, the model systems have been used in a nanotectonic approach to biomimetic materials synthesis, with possible applications to the optimisation of Al-containing materials such as ceramics or composite films. Bearing this aim in mind, the interactions of the prepared aluminium species with the model protein BSA and a bioelastomer, elastin, were monitored and the resulting composite materials characterised. The methodology developed for the synthesis and characterisation of pure A1 species and A1 species/biomolecule systems is a robust base for further studies spanning research fields such as Chemistry, Biology or Environmental sciences, and possess a large potential for application to industrial products and processes.

Analysis system for characterisation of simple, low-cost microfluidic components

NASA Astrophysics Data System (ADS)

Smith, Suzanne; Naidoo, Thegaran; Nxumalo, Zandile; Land, Kevin; Davies, Emlyn; Fourie, Louis; Marais, Philip; Roux, Pieter

2014-06-01

There is an inherent trade-off between cost and operational integrity of microfluidic components, especially when intended for use in point-of-care devices. We present an analysis system developed to characterise microfluidic components for performing blood cell counting, enabling the balance between function and cost to be established quantitatively. Microfluidic components for sample and reagent introduction, mixing and dispensing of fluids were investigated. A simple inlet port plugging mechanism is used to introduce and dispense a sample of blood, while a reagent is released into the microfluidic system through compression and bursting of a blister pack. Mixing and dispensing of the sample and reagent are facilitated via air actuation. For these microfluidic components to be implemented successfully, a number of aspects need to be characterised for development of an integrated point-of-care device design. The functional components were measured using a microfluidic component analysis system established in-house. Experiments were carried out to determine: 1. the force and speed requirements for sample inlet port plugging and blister pack compression and release using two linear actuators and load cells for plugging the inlet port, compressing the blister pack, and subsequently measuring the resulting forces exerted, 2. the accuracy and repeatability of total volumes of sample and reagent dispensed, and 3. the degree of mixing and dispensing uniformity of the sample and reagent for cell counting analysis. A programmable syringe pump was used for air actuation to facilitate mixing and dispensing of the sample and reagent. Two high speed cameras formed part of the analysis system and allowed for visualisation of the fluidic operations within the microfluidic device. Additional quantitative measures such as microscopy were also used to assess mixing and dilution accuracy, as well as uniformity of fluid dispensing - all of which are important requirements towards the successful implementation of a blood cell counting system.

Entanglement hamiltonian and entanglement contour in inhomogeneous 1D critical systems

NASA Astrophysics Data System (ADS)

Tonni, Erik; Rodríguez-Laguna, Javier; Sierra, Germán

2018-04-01

Inhomogeneous quantum critical systems in one spatial dimension have been studied by using conformal field theory in static curved backgrounds. Two interesting examples are the free fermion gas in the harmonic trap and the inhomogeneous XX spin chain called rainbow chain. For conformal field theories defined on static curved spacetimes characterised by a metric which is Weyl equivalent to the flat metric, with the Weyl factor depending only on the spatial coordinate, we study the entanglement hamiltonian and the entanglement spectrum of an interval adjacent to the boundary of a segment where the same boundary condition is imposed at the endpoints. A contour function for the entanglement entropies corresponding to this configuration is also considered, being closely related to the entanglement hamiltonian. The analytic expressions obtained by considering the curved spacetime which characterises the rainbow model have been checked against numerical data for the rainbow chain, finding an excellent agreement.

The use of unmanned aerial systems for the mapping of legacy uranium mines.

PubMed

Martin, P G; Payton, O D; Fardoulis, J S; Richards, D A; Scott, T B

2015-05-01

Historical mining of uranium mineral veins within Cornwall, England, has resulted in a significant amount of legacy radiological contamination spread across numerous long disused mining sites. Factors including the poorly documented and aged condition of these sites as well as the highly localised nature of radioactivity limit the success of traditional survey methods. A newly developed terrain-independent unmanned aerial system [UAS] carrying an integrated gamma radiation mapping unit was used for the radiological characterisation of a single legacy mining site. Using this instrument to produce high-spatial-resolution maps, it was possible to determine the radiologically contaminated land areas and to rapidly identify and quantify the degree of contamination and its isotopic nature. The instrument was demonstrated to be a viable tool for the characterisation of similar sites worldwide. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characterisation of the high dynamic range Large Pixel Detector (LPD) and its use at X-ray free electron laser sources

NASA Astrophysics Data System (ADS)

Veale, M. C.; Adkin, P.; Booker, P.; Coughlan, J.; French, M. J.; Hart, M.; Nicholls, T.; Schneider, A.; Seller, P.; Pape, I.; Sawhney, K.; Carini, G. A.; Hart, P. A.

2017-12-01

The STFC Rutherford Appleton Laboratory have delivered the Large Pixel Detector (LPD) for MHz frame rate imaging at the European XFEL. The detector system has an active area of 0.5 m × 0.5 m and consists of a million pixels on a 500 μm pitch. Sensors have been produced from 500 μm thick Hammamatsu silicon tiles that have been bump bonded to the readout ASIC using a silver epoxy and gold stud technique. Each pixel of the detector system is capable of measuring 105 12 keV photons per image readout at 4.5 MHz. In this paper results from the testing of these detectors at the Diamond Light Source and the Linac Coherent Light Source (LCLS) are presented. The performance of the detector in terms of linearity, spatial uniformity and the performance of the different ASIC gain stages is characterised.

Enabling three-dimensional densitometric measurements using laboratory source X-ray micro-computed tomography

NASA Astrophysics Data System (ADS)

Pankhurst, M. J.; Fowler, R.; Courtois, L.; Nonni, S.; Zuddas, F.; Atwood, R. C.; Davis, G. R.; Lee, P. D.

2018-01-01

We present new software allowing significantly improved quantitative mapping of the three-dimensional density distribution of objects using laboratory source polychromatic X-rays via a beam characterisation approach (c.f. filtering or comparison to phantoms). One key advantage is that a precise representation of the specimen material is not required. The method exploits well-established, widely available, non-destructive and increasingly accessible laboratory-source X-ray tomography. Beam characterisation is performed in two stages: (1) projection data are collected through a range of known materials utilising a novel hardware design integrated into the rotation stage; and (2) a Python code optimises a spectral response model of the system. We provide hardware designs for use with a rotation stage able to be tilted, yet the concept is easily adaptable to virtually any laboratory system and sample, and implicitly corrects the image artefact known as beam hardening.

Characterisation and modelling of mixing processes in groundwaters of a potential geological repository for nuclear wastes in crystalline rocks of Sweden.

PubMed

Gómez, Javier B; Gimeno, María J; Auqué, Luis F; Acero, Patricia

2014-01-15

This paper presents the mixing modelling results for the hydrogeochemical characterisation of groundwaters in the Laxemar area (Sweden). This area is one of the two sites that have been investigated, under the financial patronage of the Swedish Nuclear Waste and Management Co. (SKB), as possible candidates for hosting the proposed repository for the long-term storage of spent nuclear fuel. The classical geochemical modelling, interpreted in the light of the palaeohydrogeological history of the system, has shown that the driving process in the geochemical evolution of this groundwater system is the mixing between four end-member waters: a deep and old saline water, a glacial meltwater, an old marine water, and a meteoric water. In this paper we put the focus on mixing and its effects on the final chemical composition of the groundwaters using a comprehensive methodology that combines principal component analysis with mass balance calculations. This methodology allows us to test several combinations of end member waters and several combinations of compositional variables in order to find optimal solutions in terms of mixing proportions. We have applied this methodology to a dataset of 287 groundwater samples from the Laxemar area collected and analysed by SKB. The best model found uses four conservative elements (Cl, Br, oxygen-18 and deuterium), and computes mixing proportions with respect to three end member waters (saline, glacial and meteoric). Once the first order effect of mixing has been taken into account, water-rock interaction can be used to explain the remaining variability. In this way, the chemistry of each water sample can be obtained by using the mixing proportions for the conservative elements, only affected by mixing, or combining the mixing proportions and the chemical reactions for the non-conservative elements in the system, establishing the basis for predictive calculations. © 2013 Elsevier B.V. All rights reserved.

Semi-Metric Topology of the Human Connectome: Sensitivity and Specificity to Autism and Major Depressive Disorder.

PubMed

Simas, Tiago; Chattopadhyay, Shayanti; Hagan, Cindy; Kundu, Prantik; Patel, Ameera; Holt, Rosemary; Floris, Dorothea; Graham, Julia; Ooi, Cinly; Tait, Roger; Spencer, Michael; Baron-Cohen, Simon; Sahakian, Barbara; Bullmore, Ed; Goodyer, Ian; Suckling, John

2015-01-01

The human functional connectome is a graphical representation, consisting of nodes connected by edges, of the inter-relationships of blood oxygenation-level dependent (BOLD) time-series measured by MRI from regions encompassing the cerebral cortices and, often, the cerebellum. Semi-metric analysis of the weighted, undirected connectome distinguishes an edge as either direct (metric), such that there is no alternative path that is accumulatively stronger, or indirect (semi-metric), where one or more alternative paths exist that have greater strength than the direct edge. The sensitivity and specificity of this method of analysis is illustrated by two case-control analyses with independent, matched groups of adolescents with autism spectrum conditions (ASC) and major depressive disorder (MDD). Significance differences in the global percentage of semi-metric edges was observed in both groups, with increases in ASC and decreases in MDD relative to controls. Furthermore, MDD was associated with regional differences in left frontal and temporal lobes, the right limbic system and cerebellum. In contrast, ASC had a broadly increased percentage of semi-metric edges with a more generalised distribution of effects and some areas of reduction. In summary, MDD was characterised by localised, large reductions in the percentage of semi-metric edges, whilst ASC is characterised by more generalised, subtle increases. These differences were corroborated in greater detail by inspection of the semi-metric backbone for each group; that is, the sub-graph of semi-metric edges present in >90% of participants, and by nodal degree differences in the semi-metric connectome. These encouraging results, in what we believe is the first application of semi-metric analysis to neuroimaging data, raise confidence in the methodology as potentially capable of detection and characterisation of a range of neurodevelopmental and psychiatric disorders.

Analysis of biomass and waste gasification lean syngases combustion for power generation using spark ignition engines.

PubMed

Marculescu, Cosmin; Cenuşă, Victor; Alexe, Florin

2016-01-01

The paper presents a study for food processing industry waste to energy conversion using gasification and internal combustion engine for power generation. The biomass we used consisted in bones and meat residues sampled directly from the industrial line, characterised by high water content, about 42% in mass, and potential health risks. Using the feedstock properties, experimentally determined, two air-gasification process configurations were assessed and numerically modelled to quantify the effects on produced syngas properties. The study also focused on drying stage integration within the conversion chain: either external or integrated into the gasifier. To comply with environmental regulations on feedstock to syngas conversion both solutions were developed in a closed system using a modified down-draft gasifier that integrates the pyrolysis, gasification and partial oxidation stages. Good quality syngas with up to 19.1% - CO; 17% - H2; and 1.6% - CH4 can be produced. The syngas lower heating value may vary from 4.0 MJ/Nm(3) to 6.7 MJ/Nm(3) depending on process configuration. The influence of syngas fuel properties on spark ignition engines performances was studied in comparison to the natural gas (methane) and digestion biogas. In order to keep H2 molar quota below the detonation value of ⩽4% for the engines using syngas, characterised by higher hydrogen fraction, the air excess ratio in the combustion process must be increased to [2.2-2.8]. The results in this paper represent valuable data required by the design of waste to energy conversion chains with intermediate gas fuel production. The data is suitable for Otto engines characterised by power output below 1 MW, designed for natural gas consumption and fuelled with low calorific value gas fuels. Copyright © 2015 Elsevier Ltd. All rights reserved.

Geophysical and hydrogeological characterisation of the impacts of on-site wastewater treatment discharge to groundwater in a poorly productive bedrock aquifer.

PubMed

Donohue, Shane; McCarthy, Valerie; Rafferty, Patrick; Orr, Alison; Flynn, Raymond

2015-08-01

Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar settings across Ireland suggest the phenomena observed in this study are more widespread than previously suspected. Copyright © 2015 Elsevier B.V. All rights reserved.

Semi-Metric Topology of the Human Connectome: Sensitivity and Specificity to Autism and Major Depressive Disorder

PubMed Central

Simas, Tiago; Chattopadhyay, Shayanti; Hagan, Cindy; Kundu, Prantik; Patel, Ameera; Holt, Rosemary; Floris, Dorothea; Graham, Julia; Ooi, Cinly; Tait, Roger; Spencer, Michael; Baron-Cohen, Simon; Sahakian, Barbara; Bullmore, Ed; Goodyer, Ian; Suckling, John

2015-01-01

Introduction The human functional connectome is a graphical representation, consisting of nodes connected by edges, of the inter-relationships of blood oxygenation-level dependent (BOLD) time-series measured by MRI from regions encompassing the cerebral cortices and, often, the cerebellum. Semi-metric analysis of the weighted, undirected connectome distinguishes an edge as either direct (metric), such that there is no alternative path that is accumulatively stronger, or indirect (semi-metric), where one or more alternative paths exist that have greater strength than the direct edge. The sensitivity and specificity of this method of analysis is illustrated by two case-control analyses with independent, matched groups of adolescents with autism spectrum conditions (ASC) and major depressive disorder (MDD). Results Significance differences in the global percentage of semi-metric edges was observed in both groups, with increases in ASC and decreases in MDD relative to controls. Furthermore, MDD was associated with regional differences in left frontal and temporal lobes, the right limbic system and cerebellum. In contrast, ASC had a broadly increased percentage of semi-metric edges with a more generalised distribution of effects and some areas of reduction. In summary, MDD was characterised by localised, large reductions in the percentage of semi-metric edges, whilst ASC is characterised by more generalised, subtle increases. These differences were corroborated in greater detail by inspection of the semi-metric backbone for each group; that is, the sub-graph of semi-metric edges present in >90% of participants, and by nodal degree differences in the semi-metric connectome. Conclusion These encouraging results, in what we believe is the first application of semi-metric analysis to neuroimaging data, raise confidence in the methodology as potentially capable of detection and characterisation of a range of neurodevelopmental and psychiatric disorders. PMID:26308854

Acoustic characterisation of liquid foams with an impedance tube.

PubMed

Pierre, Juliette; Guillermic, Reine-Marie; Elias, Florence; Drenckhan, Wiebke; Leroy, Valentin

2013-10-01

Acoustic measurements provide convenient non-invasive means for the characterisation of materials. We show here for the first time how a commercial impedance tube can be used to provide accurate measurements of the velocity and attenuation of acoustic waves in liquid foams, as well as their effective "acoustic" density, over the 0.5-6kHz frequency range. We demonstrate this using two types of liquid foams: a commercial shaving foam and "home-made" foams with well-controlled physico-chemical and structural properties. The sound velocity in the latter foams is found to be independent of the bubble size distribution and is very well described by Wood's law. This implies that the impedance technique may be a convenient way to measure in situ the density of liquid foams. Important questions remain concerning the acoustic attenuation, which is found to be influenced in a currently unpredictible manner by the physico-chemical composition and the bubble size distribution of the characterised foams. We confirm differences in sound velocities in the two types of foams (having the same structural properties) which suggests that the physico-chemical composition of liquid foams has a non-negligible effect on their acoustic properties.

Solutions for characterising natural landscapes in New Zealand using geographical information systems.

PubMed

Brabyn, Lars

2005-07-01

This paper explores solutions for characterising naturalness in relation to visual landscapes using Geographical Information System (GIS). It is argued that planners need to identify natural landscapes and monitor changes in their extent. Just like the indices that have been developed to describe the state of the economy, indices need to be developed that monitor the state of natural landscapes. The complications in characterising natural landscapes are outlined but it is argued that there is a need to develop definitions of natural landscapes that can be operationalised with a GIS. This will have the advantages of the efficiency of the technology and that the definition will be explicit and the implementation will be independent of the operator. Several GIS solutions are provided and these are an analysis of landcover, a density analysis of roads and utilities, and an analysis of property sizes. The analysis of property sizes is sensitive to many human modifications of the landscape because many developments begin with the subdivision of properties. However, it is argued in this paper that no one definition will suffice and that all three methods provide different, yet important, insights into natural landscape character. An aggregate classification of naturalness based on the majority value of the indices is demonstrated as well as a range of techniques for expressing the uncertainty of the aggregate classification.

Characterisation of an OCS-dependent severe asthma population treated with mepolizumab.

PubMed

Prazma, C M; Wenzel, S; Barnes, N; Douglass, J A; Hartley, B F; Ortega, H

2014-12-01

A subpopulation of patients with asthma treated with maximal inhaled treatments is unable to maintain asthma control and requires additional therapy with oral corticosteroids (OCS); a subset of this population continues to have frequent exacerbations. Alternate treatment options are needed as daily use of OCS is associated with significant systemic adverse effects that affect many body systems and have a direct association with the dose and duration of OCS use. We compared the population demographics, medical conditions and efficacy responses of the OCS-dependent group from the DREAM study of mepolizumab with the group not managed with daily OCS. NCT01000506. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Characterisation of minimalist co-assembled fluorenylmethyloxycarbonyl self-assembling peptide systems for presentation of multiple bioactive peptides.

PubMed

Horgan, Conor C; Rodriguez, Alexandra L; Li, Rui; Bruggeman, Kiara F; Stupka, Nicole; Raynes, Jared K; Day, Li; White, John W; Williams, Richard J; Nisbet, David R

2016-07-01

The nanofibrillar structures that underpin self-assembling peptide (SAP) hydrogels offer great potential for the development of finely tuned cellular microenvironments suitable for tissue engineering. However, biofunctionalisation without disruption of the assembly remains a key issue. SAPS present the peptide sequence within their structure, and studies to date have typically focused on including a single biological motif, resulting in chemically and biologically homogenous scaffolds. This limits the utility of these systems, as they cannot effectively mimic the complexity of the multicomponent extracellular matrix (ECM). In this work, we demonstrate the first successful co-assembly of two biologically active SAPs to form a coassembled scaffold of distinct two-component nanofibrils, and demonstrate that this approach is more bioactive than either of the individual systems alone. Here, we use two bioinspired SAPs from two key ECM proteins: Fmoc-FRGDF containing the RGD sequence from fibronectin and Fmoc-DIKVAV containing the IKVAV sequence from laminin. Our results demonstrate that these SAPs are able to co-assemble to form stable hybrid nanofibres containing dual epitopes. Comparison of the co-assembled SAP system to the individual SAP hydrogels and to a mixed system (composed of the two hydrogels mixed together post-assembly) demonstrates its superior stable, transparent, shear-thinning hydrogels at biological pH, ideal characteristics for tissue engineering applications. Importantly, we show that only the coassembled hydrogel is able to induce in vitro multinucleate myotube formation with C2C12 cells. This work illustrates the importance of tissue engineering scaffold functionalisation and the need to develop increasingly advanced multicomponent systems for effective ECM mimicry. Successful control of stem cell fate in tissue engineering applications requires the use of sophisticated scaffolds that deliver biological signals to guide growth and differentiation. The complexity of such processes necessitates the presentation of multiple signals in order to effectively mimic the native extracellular matrix (ECM). Here, we establish the use of two biofunctional, minimalist self-assembling peptides (SAPs) to construct the first co-assembled SAP scaffold. Our work characterises this construct, demonstrating that the physical, chemical, and biological properties of the peptides are maintained during the co-assembly process. Importantly, the coassembled system demonstrates superior biological performance relative to the individual SAPs, highlighting the importance of complex ECM mimicry. This work has important implications for future tissue engineering studies. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Wheat germ-based protein libraries for the functional characterisation of the Arabidopsis E2 ubiquitin conjugating enzymes and the RING-type E3 ubiquitin ligase enzymes.

PubMed

Ramadan, Abdelaziz; Nemoto, Keiichirou; Seki, Motoaki; Shinozaki, Kazuo; Takeda, Hiroyuki; Takahashi, Hirotaka; Sawasaki, Tatsuya

2015-11-10

Protein ubiquitination is a ubiquitous mechanism in eukaryotes. In Arabidopsis, ubiquitin modification is mainly mediated by two ubiquitin activating enzymes (E1s), 37 ubiquitin conjugating enzymes (E2s), and more than 1300 predicted ubiquitin ligase enzymes (E3s), of which ~470 are RING-type E3s. A large proportion of the RING E3's gene products have yet to be characterised in vitro, likely because of the laborious work involved in large-scale cDNA cloning and protein expression, purification, and characterisation. In addition, several E2s, which might be necessary for the activity of certain E3 ligases, cannot be expressed by Escherichia coli or cultured insect cells and, therefore, remain uncharacterised. Using the RIKEN Arabidopsis full-length cDNA library (RAFL) with the 'split-primer' PCR method and a wheat germ cell-free system, we established protein libraries of Arabidopsis E2 and RING E3 enzymes. We expressed 35 Arabidopsis E2s including six enzymes that have not been previously expressed, and 204 RING proteins, most of which had not been functionally characterised. Thioester assays using dithiothreitol (DTT) showed DTT-sensitive ubiquitin thioester formation for all E2s expressed. In expression assays of RING proteins, 31 proteins showed high molecular smears, which are probably the result of their functional activity. The activities of another 27 RING proteins were evaluated with AtUBC10 and/or a group of different E2s. All the 27 RING E3s tested showed ubiquitin ligase activity, including 17 RING E3s. Their activities are reported for the first time. The wheat germ cell-free system used in our study, which is a eukaryotic expression system and more closely resembles the endogenous expression of plant proteins, is very suitable for expressing Arabidopsis E2s and RING E3s in their functional form. In addition, the protein libraries described here can be used for further understanding E2-E3 specificities and as platforms for protein-protein interaction screening.

Dynamics of a vertical-flow windrow vermicomposting system.

PubMed

Hanc, Ales; Castkova, Tereza; Kuzel, Stanislav; Cajthaml, Tomas

2017-11-01

Large-scale vermicomposting under outdoor conditions may differ from small-scale procedures in the laboratory. The present study evaluated changes in selected properties of a large-scale vertical-flow windrow vermicomposting system with continuous feeding with household biowaste. The windrow profile was divided into five layers of differing thickness and age after more than 12 months of vermicomposting. The top layer (0-30 cm, age <3 months) was characterised by partially decomposed organic matter with a high pH value and an elevated carbon/nitrogen (C/N) ratio. The earthworm biomass was 15 g kg -1 with a population density of 125 earthworms per kilogram predominantly found in clusters. The greatest amount of fungi (3.5 µg g -1 dw) and bacteria (62 µg g -1 dw) (expressed as phospholipid fatty acid analysis) was found in this layer. Thus, the top layer could be used for an additional cycle of windrow vermicomposting and for the preparation of aqueous extracts to protect plants against diseases. The lower layers (graduated by 30 cm and by 3 months of age) were mature as reflected by the low content of ammonia nitrogen, ratio of ammonia to nitrate nitrogen and dissolved organic carbon, and high ion-exchange capacity and its ratio to carbon. These layers were characterised by elevated values for electrical conductivity, total content of nutrients, available magnesium content, and a relatively large bacterial/fungal ratio. On the basis of the observed properties, the bottom layers were predetermined as effective fertilisers.

Characterisation of HFBII biosurfactant production and foam fractionation with and without antifoaming agents.

PubMed

Winterburn, James B; Russell, Andrew B; Martin, Peter J

2011-05-01

The effects of foaming on the production of the hydrophobin protein HFBII by fermentation have been investigated at two different scales. The foaming behaviour was characterised in standard terms of the product enrichment and recovery achieved. Additional specific attention was given to the rate at which foam, product and biomass overflowed from the fermentation system in order to assess the utility of foam fractionation for HFBII recovery. HFBII was expressed as an extracellular product during fed-batch fermentations with a genetically modified strain of Saccharomyces cerevisiae, which were carried out with and without the antifoam Struktol J647. In the presence of antifoam, HFBII production is shown to be largely unaffected by process scale, with similar yields of HFBII on dry matter obtained. More variation in HFBII yield was observed between fermentations without antifoam. In fermentations without antifoam, a maximum HFBII enrichment in the foam phase of 94.7 was measured with an overall enrichment, averaged over all overflowed material throughout the whole fermentation, of 54.6 at a recovery of 98.1%, leaving a residual HFBII concentration of 5.3 mg L(-1) in the fermenter. It is also shown that uncontrolled foaming resulted in reduced concentration of biomass in the fermenter vessel, affecting total production. This study illustrates the potential of foam fractionation for efficient recovery of HFBII through simultaneous high enrichment and recovery which are greater than those reported for similar systems.

Work Organisation, Forms of Employee Learning and National Systems of Education and Training

ERIC Educational Resources Information Center

Lorenz, Edward; Lundvall, Bengt-Åke; Kraemer-Mbula, Erika; Rasmussen, Palle

2016-01-01

This article uses a multi-level framework to investigate for 17 European nations the links between forms of work organisation and style of employee learning at the workplace on the one hand, and the characteristics of national educational and training systems on the other. The analysis shows that forms of work organisation characterised by…

Factors Affecting the Transition of Fifth Graders to the Academic Track in the Czech Republic

ERIC Educational Resources Information Center

Straková, Jana; Greger, David; Soukup, Petr

2016-01-01

The Czech education system is characterised by early tracking and high educational inequalities. The most controversial element of the system is the academic track, which is attended by students after the completion of primary school. The paper focuses on fifth graders' application process and their success in entrance examinations. The process is…

The Quest for Innovation and Entrepreneurship: The Changing Role of University in East Asia

ERIC Educational Resources Information Center

Mok, Ka Ho

2012-01-01

This article critically reviews the national innovation systems of the four little tigers in East Asia, namely Hong Kong, Singapore, Taiwan and South Korea, in fostering R&D and technological research. A national innovation system is characterised by the interactions between the state, industries and universities in promoting innovation. This…

Characterising an aluminium oxide dosimetry system.

PubMed

Conheady, Clement F; Gagliardi, Frank M; Ackerly, Trevor

2015-09-01

In vivo dosimetry is recommended as a defence-in-depth strategy in radiotherapy treatments and is currently employed by clinics around the world. The characteristics of a new optically stimulated luminescence dosimetry system were investigated for the purpose of replacing an aging thermoluminescence dosimetry system for in vivo dosimetry. The stability of the system was not sufficient to satisfy commissioning requirements and therefore it has not been released into clinical service at this time.

Flash-sourcing or the rapid detection and characterisation of earthquake effects through clickstream data analysis

NASA Astrophysics Data System (ADS)

Bossu, R.; Mazet-Roux, G.; Roussel, F.; Frobert, L.

2011-12-01

Rapid characterisation of earthquake effects is essential for a timely and appropriate response in favour of victims and/or of eyewitnesses. In case of damaging earthquakes, any field observations that can fill the information gap characterising their immediate aftermath can contribute to more efficient rescue operations. This paper presents the last developments of a method called "flash-sourcing" addressing these issues. It relies on eyewitnesses, the first informed and the first concerned by an earthquake occurrence. More precisely, their use of the EMSC earthquake information website (www.emsc-csem.org) is analysed in real time to map the area where the earthquake was felt and identify, at least under certain circumstances zones of widespread damage. The approach is based on the natural and immediate convergence of eyewitnesses on the website who rush to the Internet to investigate cause of the shaking they just felt causing our traffic to increase The area where an earthquake was felt is mapped simply by locating Internet Protocol (IP) addresses during traffic surges. In addition, the presence of eyewitnesses browsing our website within minutes of an earthquake occurrence excludes the possibility of widespread damage in the localities they originate from: in case of severe damage, the networks would be down. The validity of the information derived from this clickstream analysis is confirmed by comparisons with EMS98 macroseismic map obtained from online questionnaires. The name of this approach, "flash-sourcing", is a combination of "flash-crowd" and "crowdsourcing" intending to reflect the rapidity of the data collation from the public. For computer scientists, a flash-crowd names a traffic surge on a website. Crowdsourcing means work being done by a "crowd" of people; It also characterises Internet and mobile applications collecting information from the public such as online macroseismic questionnaires. Like crowdsourcing techniques, flash-sourcing is a crowd-to-agency system, but unlike them it is not based on declarative information (e.g. answers to a questionnaire) but on implicit data, clickstream observed on our website. We present first the main improvements of the method, improved detection of traffic surges, and a way to instantly map areas affected by severe damage or network disruptions. The second part describes how the derived information improves and fastens public earthquake information and, beyond seismology, what it can teach us on public behaviour when facing an earthquake. Finally, the discussion will focus on the future evolutions and how flash-sourcing could ultimately improve earthquake response.

Preliminary characterisation of new glass reference materials (GSA-1G, GSC-1G, GSD-1G and GSE-1G) by laser ablation-inductively coupled plasma-mass spectrometry using 193 nm, 213 nm and 266 nm wavelengths

USGS Publications Warehouse

Guillong, M.; Hametner, K.; Reusser, E.; Wilson, S.A.; Gunther, D.

2005-01-01

New glass reference materials GSA-1G, GSC-1G, GSD-1G and GSE-1G have been characterised using a prototype solid state laser ablation system capable of producing wavelengths of 193 nm, 213 nm and 266 nm. This system allowed comparison of the effects of different laser wavelengths under nearly identical ablation and ICP operating conditions. The wavelengths 213 nm and 266 nm were also used at higher energy densities to evaluate the influence of energy density on quantitative analysis. In addition, the glass reference materials were analysed using commercially available 266 nm Nd:YAG and 193 nm ArF excimer lasers. Laser ablation analysis was carried out using both single spot and scanning mode ablation. Using laser ablation ICP-MS, concentrations of fifty-eight elements were determined with external calibration to the NIST SRM 610 glass reference material. Instead of applying the more common internal standardisation procedure, the total concentration of all element oxide concentrations was normalised to 100%. Major element concentrations were compared with those determined by electron microprobe. In addition to NIST SRM 610 for external calibration, USGS BCR-2G was used as a more closely matrix-matched reference material in order to compare the effect of matrix-matched and non matrix-matched calibration on quantitative analysis. The results show that the various laser wavelengths and energy densities applied produced similar results, with the exception of scanning mode ablation at 266 nm without matrix-matched calibration where deviations up to 60% from the average were found. However, results acquired using a scanning mode with a matrix-matched calibration agreed with results obtained by spot analysis. The increased abundance of large particles produced when using a scanning ablation mode with NIST SRM 610, is responsible for elemental fractionation effects caused by incomplete vaporisation of large particles in the ICP.

Ionospheric Modelling using GPS to Calibrate the MWA. II: Regional Ionospheric Modelling using GPS and GLONASS to Estimate Ionospheric Gradients

NASA Astrophysics Data System (ADS)

Arora, B. S.; Morgan, J.; Ord, S. M.; Tingay, S. J.; Bell, M.; Callingham, J. R.; Dwarakanath, K. S.; For, B.-Q.; Hancock, P.; Hindson, L.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kapińska, A. D.; Lenc, E.; McKinley, B.; Offringa, A. R.; Procopio, P.; Staveley-Smith, L.; Wayth, R. B.; Wu, C.; Zheng, Q.

2016-07-01

We estimate spatial gradients in the ionosphere using the Global Positioning System and GLONASS (Russian global navigation system) observations, utilising data from multiple Global Positioning System stations in the vicinity of Murchison Radio-astronomy Observatory. In previous work, the ionosphere was characterised using a single-station to model the ionosphere as a single layer of fixed height and this was compared with ionospheric data derived from radio astronomy observations obtained from the Murchison Widefield Array. Having made improvements to our data quality (via cycle slip detection and repair) and incorporating data from the GLONASS system, we now present a multi-station approach. These two developments significantly improve our modelling of the ionosphere. We also explore the effects of a variable-height model. We conclude that modelling the small-scale features in the ionosphere that have been observed with the MWA will require a much denser network of Global Navigation Satellite System stations than is currently available at the Murchison Radio-astronomy Observatory.

Soft active matter: a contemporary example of Edwardsian statistical mechanics

NASA Astrophysics Data System (ADS)

Liverpool, Tanniemola

Colonies of swimming bacteria, algae or spermatozoa are examples of active systems composed of interacting units that consume energy and collectively generate motion and mechanical stresses. Due to the anisotropy of their interactions, these active particles can exhibit orientational order at high concentrations and have been called ``living liquid crystals''. Biology at the cellular and multicellular scale provides numerous examples of these active systems. They provide a novel class of experimentally accessible system far from equilibrium. Their rich collective behaviour includes non-equilibrium phase transitions and pattern formation on mesoscopic scales. Interestingly however, some of the theoretical insights gained from field theories applied to equilibrium soft matter systems can be used to explain aspects of their behaviour, but with a number of surprising new twists. I will describe and summarise recent theoretical results characterising the behaviour of such soft active systems highlighting in particular the effects of their internal dynamics on their macroscopic behaviour. With support of the EPSRC Grant No. EP/G026440/1.

Freeform surface measurement and characterisation using a toolmakers microscope

NASA Astrophysics Data System (ADS)

Seung-yin Wong, Francis; Chauh, Kong-Bieng; Venuvinod, Patri K.

2014-03-01

Current freeform surface (FFS) characterization systems mainly cover aspects related to computer-aided design/manufacture (CAD/CAM). This paper describes a new approach that extends into computer-aided inspection (CAI).The following novel features are addressed: blacksquare Feature recognition and extraction from surface data blacksquare Characterisation of properties of the surface's M and N vectors at individual vertex blacksquare Development of a measuring plan using a toolmakers microscope for the inspection of the FFS blacksquare Inspection of the actual FFS produced by CNC milling blacksquare Verification of the measurement results and comparison with the CAD design data Tests have shown that the deviations between the CAI and CAD data were within the estimated uncertainty limits.

In vitro cell irradiation systems based on 210Po alpha source: construction and characterisation

NASA Technical Reports Server (NTRS)

Szabo, J.; Feher, I.; Palfalvi, J.; Balashazy, I.; Dam, A. M.; Polonyi, I.; Bogdandi, E. N.

2002-01-01

One way of studying the risk to human health of low-level radiation exposure is to make biological experiments on living cell cultures. Two 210Po alpha-particle emitting devices, with 0.5 and 100 MBq activity, were designed and constructed to perform such experiments irradiating monolayers of cells. Estimates of dose rate at the cell surface were obtained from measurements by a PIPS alpha-particle spectrometer and from calculations by the SRIM 2000, Monte Carlo charged particle transport code. Particle fluence area distributions were measured by solid state nuclear track detectors. The design and dosimetric characterisation of the devices are discussed. c2002 Elsevier Science Ltd. All rights reserved.

Investigation of the effect of ambient conditions on the performance of solid desiccant cooling cycles

NASA Astrophysics Data System (ADS)

Panaras, G.; Mathioulakis, E.; Belessiotis, V.

2018-01-01

The operation of desiccant air-conditioning systems is characterised by processes implemented to the moist air of the environment; it is, thus, expected to be affected by ambient conditions. The present work aims at quantifying this influence on the basis of an easy-to-implement, steady-state model of the system, presenting an efficiency factors approach, which has been experimentally validated. The analysis examines the behaviour of the ventilation and the recirculation cycles, which constitute the marginal cases regarding the achieved values of the outside air fraction, given the ambient conditions, the desired regeneration temperature and the efficiency of the involved components. The fact of a desiccant cycle undergoing a set of changing ambient conditions by its actual operation is also considered in the analysis. The results provide useful information for the selection of the optimum configuration to the designer of a desiccant air-conditioning system.

Recent advances in therapeutic recruitment of mammalian RNAi and bacterial CRISPR-Cas DNA interference pathways as emerging antiviral strategies.

PubMed

Chin, Wei-Xin; Ang, Swee Kim; Chu, Justin Jang Hann

2017-01-01

In invertebrate eukaryotes and prokaryotes, respectively, the RNAi and clustered regularly interspaced short palindromic repeats-CRISPR-associated (CRISPR-Cas) pathways are highly specific and efficient RNA and DNA interference systems, and are well characterised as potent antiviral systems. It has become possible to recruit or reconstitute these pathways in mammalian cells, where they can be directed against desired host or viral targets. The RNAi and CRISPR-Cas systems can therefore yield ideal antiviral therapeutics, capable of specific and efficient viral inhibition with minimal off-target effects, but development of such therapeutics can be slow. This review covers recent advances made towards developing RNAi or CRISPR-Cas strategies for clinical use. These studies address the delivery, toxicity or target design issues that typically plague the in vivo or clinical use of these technologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ground Penetrating Radar as a Contextual Sensor for Multi-Sensor Radiological Characterisation

PubMed Central

Ukaegbu, Ikechukwu K.; Gamage, Kelum A. A.

2017-01-01

Radioactive sources exist in environments or contexts that influence how they are detected and localised. For instance, the context of a moving source is different from a stationary source because of the effects of motion. The need to incorporate this contextual information in the radiation detection and localisation process has necessitated the integration of radiological and contextual sensors. The benefits of the successful integration of both types of sensors is well known and widely reported in fields such as medical imaging. However, the integration of both types of sensors has also led to innovative solutions to challenges in characterising radioactive sources in non-medical applications. This paper presents a review of such recent applications. It also identifies that these applications mostly use visual sensors as contextual sensors for characterising radiation sources. However, visual sensors cannot retrieve contextual information about radioactive wastes located in opaque environments encountered at nuclear sites, e.g., underground contamination. Consequently, this paper also examines ground-penetrating radar (GPR) as a contextual sensor for characterising this category of wastes and proposes several ways of integrating data from GPR and radiological sensors. Finally, it demonstrates combined GPR and radiation imaging for three-dimensional localisation of contamination in underground pipes using radiation transport and GPR simulations. PMID:28387706

Characterisation of metals in the electronic waste of complex mixtures of end-of-life ICT products for development of cleaner recovery technology.

PubMed

Sun, Z H I; Xiao, Y; Sietsma, J; Agterhuis, H; Visser, G; Yang, Y

2015-01-01

Recycling of valuable metals from electronic waste, especially complex mixtures of end-of-life information and communication technology (ICT) products, is of great difficulty due to their complexity and heterogeneity. One of the important reasons is the lack of comprehensive characterisation on such materials, i.e. accurate compositions, physical/chemical properties. In the present research, we focus on developing methodologies for the characterisation of metals in an industrially processed ICT waste. The morphology, particle size distribution, compositional distribution, occurrence, liberation as well as the thermo-chemical properties of the ICT waste were investigated with various characterisation techniques, including X-ray Fluorescence Spectrometry (XRF), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) with energy dispersed spectroscopy (EDS). Due to the high heterogeneity of the material, special sample preparation procedures were introduced to minimise the discrepancies during compositional analyses. As a result, a clearer overview of the ICT waste has been reached. This research provides better understanding of the extractability of each metal and improves the awareness of potential obstacles for extraction. It will lead to smarter decisions during further development of a clean and effective recovery process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Processing of carbamazepine-PEG 4000 solid dispersions with supercritical carbon dioxide: preparation, characterisation, and in vitro dissolution.

PubMed

Moneghini, M; Kikic, I; Voinovich, D; Perissutti, B; Filipović-Grcić, J

2001-07-03

The purpose of this study was to apply the attractive technique of the supercritical fluid to the preparation of solvent-free solid dispersions. In particular, the gas antisolvent crystallisation technique (GAS), using supercritical carbon dioxide as processing medium, has been considered to prepare an enhanced release dosage form for of the poorly soluble carbamazepine, employing PEG 4000 as a hydrophilic carrier. The physical characterisation of the systems using laser granulometer, powder X-ray diffraction, thermal analyses, and scanning electron microscopy was carried out in order to understand the influence of this technological process on the physical status of the drug. The results of the physical characterisation attested a substantial correspondence of the solid state of the drug before and after treatment with GAS technique, whereas a pronounced change in size and morphology of the drug crystals was noticed. The dramatic reduction of the dimensions and the better crystal shape, together with the presence of the hydrophilic polymer determined a remarkable enhancement of the in vitro drug dissolution rate.

Hibiscus sabdariffa L. - a phytochemical and pharmacological review.

PubMed

Da-Costa-Rocha, Inês; Bonnlaender, Bernd; Sievers, Hartwig; Pischel, Ivo; Heinrich, Michael

2014-12-15

Hibiscus sabdariffa L. (Hs, roselle; Malvaceae) has been used traditionally as a food, in herbal drinks, in hot and cold beverages, as a flavouring agent in the food industry and as a herbal medicine. In vitro and in vivo studies as well as some clinical trials provide some evidence mostly for phytochemically poorly characterised Hs extracts. Extracts showed antibacterial, anti-oxidant, nephro- and hepato-protective, renal/diuretic effect, effects on lipid metabolism (anti-cholesterol), anti-diabetic and anti-hypertensive effects among others. This might be linked to strong antioxidant activities, inhibition of α-glucosidase and α-amylase, inhibition of angiotensin-converting enzymes (ACE), and direct vaso-relaxant effect or calcium channel modulation. Phenolic acids (esp. protocatechuic acid), organic acid (hydroxycitric acid and hibiscus acid) and anthocyanins (delphinidin-3-sambubioside and cyanidin-3-sambubioside) are likely to contribute to the reported effects. More well designed controlled clinical trials are needed which use phytochemically characterised preparations. Hs has an excellent safety and tolerability record. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Approximate relationship between frequency-dependent skin depth resolved from geoelectromagnetic pedotransfer function and depth of investigation resolved from geoelectrical measurements: A case study of coastal formation, southern Nigeria

NASA Astrophysics Data System (ADS)

George, N. J.; Obiora, D. N.; Ekanem, A. M.; Akpan, A. E.

2016-10-01

The task involved in the interpretation of Vertical Electrical Sounding (VES) data is how to get unique results in the absence/limited number of borehole information, which is usually limited to information on the spot. Geological and geochemical mapping of electrical properties are usually limited to direct observations on the surface and therefore, conclusions and extrapolations that can be drawn about the system electrical characteristics and possible underlying structures may be masked as geology changes with positions. The electrical resistivity study pedotransfer functions (PTFs) have been linked with the electromagnetic (EM) resolved PTFs at chosen frequencies of skin/penetration depth corresponding to the VES resolved investigation depth in order to determine the local geological attributes of hydrogeological repository in the coastal formation dominated with fine sand. The illustrative application of effective skin depth depicts that effective skin depth has direct relation with the EM response of the local source over the layered earth and thus, can be linked to the direct current earth response functions as an aid for estimating the optimum depth and electrical parameters through comparative analysis. Though the VES and EM resolved depths of investigation at appropriate effective and theoretical frequencies have wide gaps, diagnostic relations characterising the subsurface depth of interest have been established. The determining factors of skin effect have been found to include frequency/period, resistivity/conductivity, absorption/attenuation coefficient and energy loss factor. The novel diagnostic relations and their corresponding constants between 1-D resistivity data and EM skin depth are robust PTFs necessary for checking the accuracy associated with the non-unique interpretations that characterise the 1-D resistivity data, mostly when lithostratigraphic data are not available.

Improving the biological nitrogen removal process in pharmaceutical wastewater treatment plants: a case study.

PubMed

Torrijos, M; Carrera, J; Lafuente, J

2004-04-01

The Biological Nitrogen Removal (BNR) process of some pharmaceutical wastewater treatment plants has important operational problems. This study shows that, in order to solve these problems, the design of industrial BNR processes should start by analysing three key parameters: the characteristics of the wastewater load, the determination of the maximum TKN removal rate and the detection of toxic or inhibitory compounds in the wastewater. A case study of this analysis in pharmaceutical wastewater is presented here. In this case, the conventional TKN analytical method does not make an accurate characterisation of the wastewater load because it measures a concentration of 100 mg TKN l(-1) whereas the real concentration, determined with a modified TKN analytical method, is 150-500 mg TKN l(-1). Also, the TKN removal of the treatment system is insufficient in some periods because it falls below legal requirements. This problem might be a consequence of the wrong characterisation of wastewater during the design process. The maximum TKN removal at 27 degrees C (24 mg N g VSS(-1) d(-1) or 197 mg N l(-1) d(-1)) was evaluated in a pilot-scale plant. This value is six times greater than the average NLR applied in the full-scale plant. Finally, some of the components of the wastewater, such as p-phenylenediamine, might have inhibitory or toxic effects on the biological process. P-phenylenediamine causes a large decrease in the nitrification rate. This effect was determined by respirometry. This methodology shows that the effect is mainly inhibitory with a contact time of 30 min and if the contact time is longer, 14 hours, a toxic effect is observed.

The effects of the stellar wind and orbital motion on the jets of high-mass microquasars

NASA Astrophysics Data System (ADS)

Bosch-Ramon, V.; Barkov, M. V.

2016-05-01

Context. High-mass microquasar jets propagate under the effect of the wind from the companion star, and the orbital motion of the binary system. The stellar wind and the orbit may be dominant factors determining the jet properties beyond the binary scales. Aims: This is an analytical study, performed to characterise the effects of the stellar wind and the orbital motion on the jet properties. Methods: Accounting for the wind thrust transferred to the jet, we derive analytical estimates to characterise the jet evolution under the impact of the stellar wind. We include the Coriolis force effect, induced by orbital motion and enhanced by the wind's presence. Large-scale evolution of the jet is sketched, accounting for wind-to-jet thrust transfer, total energy conservation, and wind-jet flow mixing. Results: If the angle of the wind-induced jet bending is larger than its half-opening angle, the following is expected: (I) a strong recollimation shock; (II) bending against orbital motion, caused by Coriolis forces and enhanced by the wind presence; and (III) non-ballistic helical propagation further away. Even if disrupted, the jet can re-accelerate due to ambient pressure gradients, but wind entrainment can weaken this acceleration. On large scales, the opening angle of the helical structure is determined by the wind-jet thrust relation, and the wind-loaded jet flow can be rather slow. Conclusions: The impact of stellar winds on high-mass microquasar jets can yield non-ballistic helical jet trajectories, jet partial disruption and wind mixing, shocks, and possibly non-thermal emission. Among other observational diagnostics, such as radiation variability at any band, the radio morphology on milliarcsecond scales can be informative on the wind-jet interaction.

Spin precession and spin Hall effect in monolayer graphene/Pt nanostructures

NASA Astrophysics Data System (ADS)

Savero Torres, W.; Sierra, J. F.; Benítez, L. A.; Bonell, F.; Costache, M. V.; Valenzuela, S. O.

2017-12-01

Spin Hall effects have surged as promising phenomena for spin logics operations without ferromagnets. However, the magnitude of the detected electric signals at room temperature in metallic systems has been so far underwhelming. Here, we demonstrate a two-order of magnitude enhancement of the signal in monolayer graphene/Pt devices when compared to their fully metallic counterparts. The enhancement stems in part from efficient spin injection and the large spin resistance of graphene but we also observe 100% spin absorption in Pt and find an unusually large effective spin Hall angle of up to 0.15. The large spin-to-charge conversion allows us to characterise spin precession in graphene under the presence of a magnetic field. Furthermore, by developing an analytical model based on the 1D diffusive spin-transport, we demonstrate that the effective spin-relaxation time in graphene can be accurately determined using the (inverse) spin Hall effect as a means of detection. This is a necessary step to gather full understanding of the consequences of spin absorption in spin Hall devices, which is known to suppress effective spin lifetimes in both metallic and graphene systems.

Analysis of Multilayered Printed Circuit Boards using Computed Tomography

DTIC Science & Technology

2014-05-01

complex PCBs that present a challenge for any testing or fault analysis. Set-to- work testing and fault analysis of any electronic circuit require...Electronic Warfare and Radar Division in December 2010. He is currently in Electro- Optic Countermeasures Group. Samuel works on embedded system design...and software optimisation of complex electro-optical systems, including the set to work and characterisation of these systems. He has a Bachelor of

Gut microbiota controls adipose tissue expansion, gut barrier and glucose metabolism: novel insights into molecular targets and interventions using prebiotics.

PubMed

Geurts, L; Neyrinck, A M; Delzenne, N M; Knauf, C; Cani, P D

2014-03-01

Crosstalk between organs is crucial for controlling numerous homeostatic systems (e.g. energy balance, glucose metabolism and immunity). Several pathological conditions, such as obesity and type 2 diabetes, are characterised by a loss of or excessive inter-organ communication that contributes to the development of disease. Recently, we and others have identified several mechanisms linking the gut microbiota with the development of obesity and associated disorders (e.g. insulin resistance, type 2 diabetes, hepatic steatosis). Among these, we described the concept of metabolic endotoxaemia (increase in plasma lipopolysaccharide levels) as one of the triggering factors leading to the development of metabolic inflammation and insulin resistance. Growing evidence suggests that gut microbes contribute to the onset of low-grade inflammation characterising these metabolic disorders via mechanisms associated with gut barrier dysfunctions. We have demonstrated that enteroendocrine cells (producing glucagon-like peptide-1, peptide YY and glucagon-like peptide-2) and the endocannabinoid system control gut permeability and metabolic endotoxaemia. Recently, we hypothesised that specific metabolic dysregulations occurring at the level of numerous organs (e.g. gut, adipose tissue, muscles, liver and brain) rely from gut microbiota modifications. In this review, we discuss the mechanisms linking gut permeability, adipose tissue metabolism, and glucose homeostasis, and recent findings that show interactions between the gut microbiota, the endocannabinoid system and the apelinergic system. These specific systems are discussed in the context of the gut-to-peripheral organ axis (intestine, adipose tissue and brain) and impacts on metabolic regulation. In the present review, we also briefly describe the impact of a variety of non-digestible nutrients (i.e. inulin-type fructans, arabinoxylans, chitin glucans and polyphenols). Their effects on the composition of the gut microbiota and activity are discussed in the context of obesity and type 2 diabetes.

Effect of sex and genotype on carcase composition and nutritional characteristics of chicken meat.

PubMed

Baeza, E; Chartrin, P; Meteau, K; Bordeau, T; Juin, H; Le Bihan-Duval, E; Lessire, M; Berri, C

2010-06-01

1. The aim of this study was to examine the effect of sex and genotype on carcase composition and nutritional and sensory characteristics of chicken meat. The "Geline de Touraine" (GT) characterised by high carcase fatness was compared with an experimental crossbreed (EC) and "Label rouge" (LR) genotype. 2. Females compared with males, and GT chickens compared with LR and EC chickens were characterised by increased carcase fatness and an increased lipid level in thigh meat. 3. In both breast and thigh meat, the percentage of monounsaturated fatty acids was increased and the percentage of polyunsaturated fatty acids was decreased. However, these effects did not affect sensory characteristics of meat particularly those of roasted breast fillets containing very low lipid level by comparison with thigh meat. 4. Finally, in our study, high carcase fatness was related to high intermuscular fatness affecting the nutritional characteristics of meat but not its sensory attributes.

The Tanzanian trauma patients' prehospital experience: a qualitative interview-based study

PubMed Central

Kuzma, Kristin; Lim, Andrew George; Kepha, Bernard; Nalitolela, Neema Evelyne; Reynolds, Teri A

2015-01-01

Objectives We sought to characterise the prehospital experience of Tanzanian trauma patients, and identify barriers and facilitators to implement community-based emergency medical systems (EMS). Settings Our study was conducted in the emergency department of an urban national referral hospital in Tanzania. Participants A convenience sample of 34 adult trauma patients, or surrogate family members, presenting or referred to an urban referral emergency department in Tanzania for treatment of injury, participated in the study. Interventions Participation in semistructured, iteratively developed interviews until saturation of responses was reached. Outcomes A grounded theory-based approach to qualitative analysis was used to identify recurrent themes. Results We characterised numerous deficiencies within the existing clinic-to-hospital referral network, including missed/delayed diagnoses, limited management capabilities at pre-referral facilities and interfacility transfer delays. Potential barriers to EMS implementation include patient financial limitations and lack of insurance, limited public infrastructure and resources, and the credibility of potential first aid responders. Potential facilitators of EMS include communities’ tendency to pool resources, individuals’ trust of other community members to be first aid responders, and faith in community leaders to organise EMS response. Participants expressed a strong desire to learn first aid. Conclusions The composite themes generated by the data suggest that there are myriad structural, financial, institutional and cultural barriers to the implementation of a formal prehospital system. However, our analysis also revealed potential facilitators to a first-responder system that takes advantage of close-knit local communities and the trust of recognised leaders in society. The results suggest favourable acceptability for community-based response by trained lay people. There is significant opportunity for care improvements with short trainings and low-cost supply planning. Further research looking at the effects of delay on outcomes in this population is needed. PMID:25916487

Three-column classification and Schatzker classification: a three- and two-dimensional computed tomography characterisation and analysis of tibial plateau fractures.

PubMed

Patange Subba Rao, Sheethal Prasad; Lewis, James; Haddad, Ziad; Paringe, Vishal; Mohanty, Khitish

2014-10-01

The aim of the study was to evaluate inter-observer reliability and intra-observer reproducibility between the three-column classification and Schatzker classification systems using 2D and 3D CT models. Fifty-two consecutive patients with tibial plateau fractures were evaluated by five orthopaedic surgeons. All patients were classified into Schatzker and three-column classification systems using x-rays and 2D and 3D CT images. The inter-observer reliability was evaluated in the first round and the intra-observer reliability was determined during the second round 2 weeks later. The average intra-observer reproducibility for the three-column classification was from substantial to excellent in all sub classifications, as compared with Schatzker classification. The inter-observer kappa values increased from substantial to excellent in three-column classification and to moderate in Schatzker classification The average values for three-column classification for all the categories are as follows: (I-III) k2D = 0.718, 95% CI 0.554-0.864, p < 0.0001 and average 3D = 0.874, 95% CI 0.754-0.890, p < 0.0001. For Schatzker classification system, the average values for all six categories are as follows: (I-VI) k2D = 0.536, 95% CI 0.365-0.685, p < 0.0001 and average k3D = 0.552 95% CI 0.405-0.700, p < 0.0001. The values are statistically significant. Statistically significant inter-observer values in both rounds were noted with the three-column classification, making it statistically an excellent agreement. The intra-observer reproducibility for the three-column classification improved as compared with the Schatzker classification. The three-column classification seems to be an effective way to characterise and classify fractures of tibial plateau.

Next generation microbiological risk assessment-Potential of omics data for hazard characterisation.

PubMed

Haddad, Nabila; Johnson, Nick; Kathariou, Sophia; Métris, Aline; Phister, Trevor; Pielaat, Annemarie; Tassou, Chrysoula; Wells-Bennik, Marjon H J; Zwietering, Marcel H

2018-04-12

According to the World Health Organization estimates in 2015, 600 million people fall ill every year from contaminated food and 420,000 die. Microbial risk assessment (MRA) was developed as a tool to reduce and prevent risks presented by pathogens and/or their toxins. MRA is organized in four steps to analyse information and assist in both designing appropriate control options and implementation of regulatory decisions and programs. Among the four steps, hazard characterisation is performed to establish the probability and severity of a disease outcome, which is determined as function of the dose of toxin and/or pathogen ingested. This dose-response relationship is subject to both variability and uncertainty. The purpose of this review/opinion article is to discuss how Next Generation Omics can impact hazard characterisation and, more precisely, how it can improve our understanding of variability and limit the uncertainty in the dose-response relation. The expansion of omics tools (e.g. genomics, transcriptomics, proteomics and metabolomics) allows for a better understanding of pathogenicity mechanisms and virulence levels of bacterial strains. Detection and identification of virulence genes, comparative genomics, analyses of mRNA and protein levels and the development of biomarkers can help in building a mechanistic dose-response model to predict disease severity. In this respect, systems biology can help to identify critical system characteristics that confer virulence and explain variability between strains. Despite challenges in the integration of omics into risk assessment, some omics methods have already been used by regulatory agencies for hazard identification. Standardized methods, reproducibility and datasets obtained from realistic conditions remain a challenge, and are needed to improve accuracy of hazard characterisation. When these improvements are realized, they will allow the health authorities and government policy makers to prioritize hazards more accurately and thus refine surveillance programs with the collaboration of all stakeholders of the food chain. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

A theoretical study of interaction effects on the remanence curves of particulate dispersions

NASA Astrophysics Data System (ADS)

Fearon, M.; Chantrell, R. W.; Wohlfarth, E. P.

1990-05-01

The remanence curves of strongly interacting fine-particle systems are investigated theoretically. It is shown that the Henkel plot of the dc demagnetisation remanence vs. the isothermal remanence is a useful representation of interactions. The form of the plot is found to be a reflection of the magnetic and physical microstructure of the material, which is consistent with experimental data. The relationship between the Henkel plot and the noise of a particulate recording medium, another property dependent on the microstructure, is also considered. The Interaction Field Factor (IFF), a single parameter characterising the non-linearity of the Henkel plot, is also investigated. The results are consistent with a previous experimental study. Finally, the effect of interactions on the Switching Field Distribution are investigated.

Confined Floodplain Dynamics on Semi-Arid Systems

NASA Astrophysics Data System (ADS)

Entwistle, N. S.

2017-12-01

Many watercourses across southern Africa are characterised by a bedrock influenced `macro-channel' created as a result of geologically recent fluvial incision into ancient planation surfaces. The rivers of the Kruger National Park in Mpumalanga Province, South Africa are no exception, displaying a varied set of channel types within a bedrock template. Contemporary flows are largely contained within the confines of this `macro-channel' and a diverse valley bottom morphology and ecology has developed in response to this flow regime coupled with intermittent fine sediment delivery from the catchment. Aerial imagery and field monitoring of the impact of two cyclone driven extreme flows and subsequent recovery phases suggests that flood impact is spatially variable with bedrock exposure greatest along watercourses already severely impacted by previous events. Subsequent system development has been characterised by the redistribution and vegetative colonisation of unconsolidated sandy sediment over bedrock. On less impacted systems vegetative induced recovery has, in contrast, been rapid with many of the species present displaying significant resilience to extreme flows forming residual pockets which are subsequently developing alongside embryonic morphologic recovery. Using these observations a model of valley bottom recovery is presented.

Construction and use of a Cupriavidus necator H16 soluble hydrogenase promoter (PSH) fusion to gfp (green fluorescent protein)

PubMed Central

Jugder, Bat-Erdene; Welch, Jeffrey; Braidy, Nady

2016-01-01

Hydrogenases are metalloenzymes that reversibly catalyse the oxidation or production of molecular hydrogen (H2). Amongst a number of promising candidates for application in the oxidation of H2 is a soluble [Ni–Fe] uptake hydrogenase (SH) produced by Cupriavidus necator H16. In the present study, molecular characterisation of the SH operon, responsible for functional SH synthesis, was investigated by developing a green fluorescent protein (GFP) reporter system to characterise PSH promoter activity using several gene cloning approaches. A PSH promoter-gfp fusion was successfully constructed and inducible GFP expression driven by the PSH promoter under de-repressing conditions in heterotrophic growth media was demonstrated in the recombinant C. necator H16 cells. Here we report the first successful fluorescent reporter system to study PSH promoter activity in C. necator H16. The fusion construct allowed for the design of a simple screening assay to evaluate PSH activity. Furthermore, the constructed reporter system can serve as a model to develop a rapid fluorescent based reporter for subsequent small-scale process optimisation experiments for SH expression. PMID:27547572

Ab initio quantum chemical calculations of the interaction between radioactive elements and imidazolium based ionic liquids

NASA Astrophysics Data System (ADS)

Saravanan, A. V. Sai; Abishek, B.; Anantharaj, R.

2018-04-01

The fundamental natures of the molecular level interaction and charge transfer between specific radioactive elements and ionic liquids of 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([BMIM]+[NTf2]-), 1-Butyl-3-methylimidazolium ethylsulfate ([BMIM]+[ES]-) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]+[BF4]-) were investigated utilising HF theory and B3LYP hybrid DFT. The ambiguity in reaction mechanism of the interacting species dictates to employ Effective Core Potential (ECP) basis sets such as UGBS, SDD, and SDDAll to account for the relativistic effects of deep core electrons in the system involving potential, heavy and hazardous radioactive elements present in nuclear waste. The SCF energy convergence of each system validates the characterisation of the molecular orbitals as a linear combination of atomic orbitals utilising fixed MO coefficients and the optimized geometry of each system is visualised based on which Mulliken partial charge analysis is carried out to account for the polarising behaviour of the radioactive element and charge transfer between the IL phase by comparison with the bare IL species.

Method for estimating protein binding capacity of polymeric systems.

PubMed

Sharma, Vaibhav; Blackwood, Keith A; Haddow, David; Hook, Lilian; Mason, Chris; Dye, Julian F; García-Gareta, Elena

2015-01-01

Composite biomaterials made from synthetic and protein-based polymers are extensively researched in tissue engineering. To successfully fabricate a protein-polymer composite, it is critical to understand how strongly the protein binds to the synthetic polymer, which occurs through protein adsorption. Currently, there is no cost-effective and simple method for characterizing this interfacial binding. To characterize this interfacial binding, we introduce a simple three-step method that involves: 1) synthetic polymer surface characterisation, 2) a quick, inexpensive and robust novel immuno-based assay that uses protein extraction compounds to characterize protein binding strength followed by 3) an in vitro 2D model of cell culture to confirm the results of the immuno-based assay. Fibrinogen, precursor of fibrin, was adsorbed (test protein) on three different polymeric surfaces: silicone, poly(acrylic acid)-coated silicone and poly(allylamine)-coated silicone. Polystyrene surface was used as a reference. Characterisation of the different surfaces revealed different chemistry and roughness. The novel immuno-based assay showed significantly stronger binding of fibrinogen to both poly(acrylic acid) and poly(allylamine) coated silicone. Finally, cell studies showed that the strength of the interaction between the protein and the polymer had an effect on cell growth. This novel immuno-based assay is a valuable tool in developing composite biomaterials of synthetic and protein-based polymers with the potential to be applied in other fields of research where protein adsorption onto surfaces plays an important role.

Efficacy and cost-effectiveness of stereotactic vacuum-assisted core biopsy of nonpalpable breast lesions: analysis of 602 biopsies performed over 5 years.

PubMed

Luparia, A; Durando, M; Campanino, P; Regini, E; Lucarelli, D; Talenti, A; Mattone, G; Mariscotti, G; Sapino, A; Gandini, G

2011-04-01

The authors sought to evaluate the diagnostic accuracy and cost-effectiveness of vacuum-assisted core biopsy (VACB) in comparison with diagnostic surgical excision for characterisation of nonpalpable breast lesions classified as Breast Imaging Reporting and Data System (BI-RADS) categories R3 and R4. From January 2004 to December 2008, we conducted 602 stereotactic, 11-gauge, VACB procedures on 243 nonpalpable breast lesions categorised as BI-RADS R3, 346 categorised as BI-RADS R4 and 13 categorised as BI-RADS R5. We calculated the diagnostic accuracy and cost savings of VACB by subtracting the cost of the stereotactic biopsy from that of the diagnostic surgical procedure. A total of 56% of the lesions were benign and required no further assessment. Lesions of uncertain malignant potential (B3) (23.6%) were debated at multidisciplinary meetings, and diagnostic surgical biopsy was recommended for 83.1% of them. All malignant lesions (B4 and B5) underwent surgical excision. VACB had a sensitivity of 94.9%, specificity of 98.3% and diagnostic accuracy of 97.7%. The cost savings per VACB procedure were 464.00 euro; by obviating 335 surgical biopsies, the overall cost savings was 155,440.00 euro over 5 years. VACB proved to have high diagnostic accuracy for characterising abnormalities at low to intermediate risk of malignancy and obviated surgical excision in about half of the cases, allowing for considerable cost savings.

Functional characterisation of metal(loid) processes in planta through the integration of synchrotron techniques and plant molecular biology

PubMed Central

Donner, Erica; Punshon, Tracy; Guerinot, Mary Lou; Lombi, Enzo

2013-01-01

Functional characterisation of the genes regulating metal(loid) homeostasis in plants is a major focus of crop biofortification, phytoremediation, and food security research. This paper focuses on the potential for advancing plant metal(loid) research by combining molecular biology and synchrotron-based techniques. Recent advances in x-ray focussing optics and fluorescence detection have greatly improved the potential of synchrotron techniques for plant science research, allowing metal(loids) to be imaged in vivo in hydrated plant tissues at sub-micron resolution. Laterally resolved metal(loid) speciation can also be determined. By using molecular techniques to probe the location of gene expression and protein localisation and combining it with this synchrotron-derived data, functional information can be effectively and efficiently assigned to specific genes. This paper provides a review of the state of the art in this field, and provides examples as to how synchrotron-based methods can be combined with molecular techniques to facilitate functional characterisation of genes in planta. PMID:22200921

[Applying the clustering technique for characterising maintenance outsourcing].

PubMed

Cruz, Antonio M; Usaquén-Perilla, Sandra P; Vanegas-Pabón, Nidia N; Lopera, Carolina

2010-06-01

Using clustering techniques for characterising companies providing health institutions with maintenance services. The study analysed seven pilot areas' equipment inventory (264 medical devices). Clustering techniques were applied using 26 variables. Response time (RT), operation duration (OD), availability and turnaround time (TAT) were amongst the most significant ones. Average biomedical equipment obsolescence value was 0.78. Four service provider clusters were identified: clusters 1 and 3 had better performance, lower TAT, RT and DR values (56 % of the providers coded O, L, C, B, I, S, H, F and G, had 1 to 4 day TAT values:

The high-throughput synthesis and phase characterisation of amphiphiles: a sweet case study.

PubMed

Feast, George C; Hutt, Oliver E; Mulet, Xavier; Conn, Charlotte E; Drummond, Calum J; Savage, G Paul

2014-03-03

A new method for the discovery of amphiphiles by using high-throughput (HT) methods to synthesise and characterise a library of galactose- and glucose-containing amphiphilic compounds is presented. The copper-catalysed azide–alkyne cycloaddition (CuAAC) “click” reaction between azide-tethered simple sugars and alkyne-substituted hydrophobic tails was employed to synthesise a library of compounds with systematic variations in chain length and unsaturation in a 24-vial array format. The liquid–crystalline phase behaviour was characterised in a HT manner by using synchrotron small-angle X-ray scattering (SSAXS). The observed structural variation with respect to chain parameters, including chain length and degree of unsaturation, is discussed, as well as hydration effects and degree of hydrogen bonding between head groups. The validity of our HT screening approach was verified by resynthesising a short-chain glucose amphiphile. A separate phase analysis of this compound confirmed the presence of numerous lyotropic liquid–crystalline phases.

High resolution melting analysis: rapid and precise characterisation of recombinant influenza A genomes

PubMed Central

2013-01-01

Background High resolution melting analysis (HRM) is a rapid and cost-effective technique for the characterisation of PCR amplicons. Because the reverse genetics of segmented influenza A viruses allows the generation of numerous influenza A virus reassortants within a short time, methods for the rapid selection of the correct recombinants are very useful. Methods PCR primer pairs covering the single nucleotide polymorphism (SNP) positions of two different influenza A H5N1 strains were designed. Reassortants of the two different H5N1 isolates were used as a model to prove the suitability of HRM for the selection of the correct recombinants. Furthermore, two different cycler instruments were compared. Results Both cycler instruments generated comparable average melting peaks, which allowed the easy identification and selection of the correct cloned segments or reassorted viruses. Conclusions HRM is a highly suitable method for the rapid and precise characterisation of cloned influenza A genomes. PMID:24028349

Potassium transport in monkey erythrocytes.

PubMed

Stewart, G W; Blackstock, E J; Hall, A C; Ellory, J C

1989-01-01

K transport in Rhesus and Cynomolgus monkey erythrocytes has been characterised and compared to that in human erythrocytes. Transport due to the NaK pump, residual (diffusional) leak, volume-, pressure- and N-ethyl-maleimide-stimulated KCl system and internal Ca2+-stimulated K channel were similar to that in man but in the monkey it differed, in lacking the loop-diuretic-sensitive NaKCl cotransport system.

Towards high performing hospital enterprise systems: an empirical and literature based design framework

NASA Astrophysics Data System (ADS)

dos Santos Fradinho, Jorge Miguel

2014-05-01

Our understanding of enterprise systems (ES) is gradually evolving towards a sense of design which leverages multidisciplinary bodies of knowledge that may bolster hybrid research designs and together further the characterisation of ES operation and performance. This article aims to contribute towards ES design theory with its hospital enterprise systems design (HESD) framework, which reflects a rich multidisciplinary literature and two in-depth hospital empirical cases from the US and UK. In doing so it leverages systems thinking principles and traditionally disparate bodies of knowledge to bolster the theoretical evolution and foundation of ES. A total of seven core ES design elements are identified and characterised with 24 main categories and 53 subcategories. In addition, it builds on recent work which suggests that hospital enterprises are comprised of multiple internal ES configurations which may generate different levels of performance. Multiple sources of evidence were collected including electronic medical records, 54 recorded interviews, observation, and internal documents. Both in-depth cases compare and contrast higher and lower performing ES configurations. Following literal replication across in-depth cases, this article concludes that hospital performance can be improved through an enriched understanding of hospital ES design.

Characterising the hydrological regime of an ungauged temporary river system: a case study.

PubMed

D'Ambrosio, Ersilia; De Girolamo, Anna Maria; Barca, Emanuele; Ielpo, Pierina; Rulli, Maria Cristina

2017-06-01

Temporary streams are characterised by specific hydrological regimes, which influence ecosystem processes, groundwater and surface water interactions, sediment regime, nutrient delivery, water quality and ecological status. This paper presents a methodology to characterise and classify the regime of a temporary river in Southern Italy based on hydrological indicators (HIs) computed with long-term daily flow records. By using a principal component analysis (PCA), a set of non-redundant indices were identified describing the main characteristics of the hydrological regime in the study area. The indicators identified were the annual maximum 30- and 90-day mean (DH4 and DH5), the number of zero flow days (DL6), flow permanence (MF) and the 6-month seasonal predictability of dry periods (SD6). A methodology was also tested to estimate selected HIs in ungauged river reaches. Watershed characteristics such as catchment area, gauging station elevation, mean watershed slope, mean annual rainfall, land use, soil hydraulic conductivity and available water content were derived for each site. Selected indicators were then linked to the catchment characteristics using a regression analysis. Finally, MF and SD6 were used to classify the river reaches on the basis of their degree of intermittency. The methodology presented in this paper constitutes a useful tool for ecologists and water resource managers in the Water Framework Directive implementation process, which requires a characterisation of the hydrological regime and a 'river type' classification for all water bodies.

Hydrothermal mineralising systems as critical systems

NASA Astrophysics Data System (ADS)

Hobbs, Bruce

2015-04-01

Hydrothermal mineralising systems as critical systems. Bruce E Hobbs1,2, Alison Ord1 and Mark A. Munro1. 1. Centre for Exploration Targeting, The University of Western Australia, M006, 35 Stirling Highway, Crawley, WA 6009, Australia. 2. CSIRO Earth and Resource Engineering, Bentley, WA, Australia Hydrothermal mineralising systems are presented as large, open chemical reactors held far from equilibrium during their life-time by the influx of heat, fluid and dissolved chemical species. As such they are nonlinear dynamical systems and need to be analysed using the tools that have been developed for such systems. Hydrothermal systems undergo a number of transitions during their evolution and this paper focuses on methods for characterising these transitions in a quantitative manner and establishing whether they resemble first or second (critical) phase transitions or whether they have some other kind of nature. Critical phase transitions are characterised by long range correlations for some parameter characteristic of the system, power-law probability distributions so that there is no characteristic length scale and a high sensitivity to perturbations; as one approaches criticality, characteristic parameters for the system scale in a power law manner with distance from the critical point. The transitions undergone in mineralised hydrothermal systems are: (i) widespread, non-localised mineral alteration involving exothermic mineral reactions that produce hydrous silicate phases, carbonates and iron-oxides, (ii) strongly localised veining, brecciation and/or stock-work formation, (iii) a series of endothermic mineral reactions involving the formation of non-hydrous silicates, sulphides and metals such as gold, (iv) multiple repetitions of transitions (ii) and (iii). We have quantified aspects of these transitions in gold deposits from the Yilgarn craton of Western Australia using wavelet transforms. This technique is convenient and fast. It enables one to establish if the transition is multifractal (and if so, quantify the multifractal spectrum) and determine the scale dependence of long range correlations or anti-correlations. The availability of long drill holes with detailed chemical analyses and mineral abundances derived from hyperspectral data enables individual ore bodies to be characterised in a quantitative manner and constraints placed on whether the various transition are possibly critical or of some other form. We also present some simple nonlinear models that produce the multifractal character and correlation scaling relations observed in these data sets,

Modelling and control of a nonlinear magnetostrictive actuator system

NASA Astrophysics Data System (ADS)

Ramli, M. H. M.; Majeed, A. P. P. Abdul; Anuar, M. A. M.; Mohamed, Z.

2018-04-01

This paper explores the implementation of a feedforward control method to a nonlinear control system, in particular, Magnetostrictive Actuators (MA) that has excellent properties of energy conversion between the mechanical and magnetic form through magnetostriction effects which could be used in actuating and sensing application. MA is known to exhibit hysteresis behaviour and it is rate dependent (the level of hysteresis depends closely on the rate of input excitation frequency). This is, nonetheless, an undesirable behaviour and has to be eliminated in realising high precision application. The MA is modelled by a phenomenological modelling approach via Prandtl-Ishlinskii (P-I) operator to characterise the hysteresis nonlinearities. A feedforward control strategy is designed and implemented to linearize and eliminate the hysteresis by model inversion. The results show that the P-I operator has the capability to model the hysteretic nonlinearity of MA with an acceptable accuracy. Furthermore, the proposed control scheme has demonstrated to be effective in providing superior trajectory tracking.

An update on diet and nutritional factors in systemic lupus erythematosus management.

PubMed

Aparicio-Soto, Marina; Sánchez-Hidalgo, Marina; Alarcón-de-la-Lastra, Catalina

2017-06-01

Systemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease characterised by multiple organ involvement and a large number of complications. SLE management remains complicated owing to the biological heterogeneity between patients and the lack of safe and specific targeted therapies. There is evidence that dietary factors can contribute to the geoepidemiology of autoimmune diseases such as SLE. Thus, diet therapy could be a promising approach in SLE owing to both its potential prophylactic effects, without the side effects of classical pharmacology, and its contribution to reducing co-morbidities and improving quality of life in patients with SLE. However, the question arises as to whether nutrients could ameliorate or exacerbate SLE and how they could modulate inflammation and immune function at a molecular level. The present review summarises preclinical and clinical experiences to provide the reader with an update of the positive and negative aspects of macro- and micronutrients and other nutritional factors, including dietary phenols, on SLE, focusing on the mechanisms of action involved.

Extensive characterisation of bioactive phenolic constituents from globe artichoke (Cynara scolymus L.) by HPLC-DAD-ESI-QTOF-MS.

PubMed

Abu-Reidah, Ibrahim M; Arráez-Román, David; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

2013-12-01

The aim of this work was to characterise the phenolic compounds in artichoke (hearts) by using HPLC coupled to DAD-ESI-QTOF-MS, which proved useful in characterising 61 phenolic and other polar compounds. Notably, of the 61 compounds characterised, 34 new phenolic compounds with their isomers have been tentatively characterised in artichoke for the first time, namely: 3 hydroxybenzoic acids, 17 hydroxycinnamic acids, 4 lignans, 7 flavones, 2 flavonols, and 1 phenol derivative. Moreover, a total of 28 isomers of previously described phenolics have also been detected. The data compiled from the qualitative polyphenol characterisation indicate that the artichoke extract analysed (Blanca de Tudela variety) could be regarded as a bioactive functional food and also as a promising source of antioxidant phenolic compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Neuroendocrine Regulation of Anxiety: Beyond the Hypothalamic-Pituitary-Adrenal Axis.

PubMed

Borrow, A P; Stranahan, A M; Suchecki, D; Yunes, R

2016-07-01

The central nervous system regulates and responds to endocrine signals, and this reciprocal relationship determines emotional processing and behavioural anxiety. Although the hypothalamic-pituitary-adrenal (HPA) axis remains the best-characterised system for this relationship, other steroid and peptide hormones are increasingly recognised for their effects on anxiety-like behaviour and reward. The present review examines recent developments related to the role of a number of different hormones in anxiety, including pregnane neurosteroids, gut peptides, neuropeptides and hormonal signals derived from fatty acids. Findings from both basic and clinical studies suggest that these alternative systems may complement or occlude stress-induced changes in anxiety and anxiety-like behaviour. By broadening the scope of mechanisms for depression and anxiety, it may be possible to develop novel strategies to attenuate stress-related psychiatric conditions. The targets for these potential therapies, as discussed in this review, encompass multiple circuits and systems, including those outside of the HPA axis. © 2016 British Society for Neuroendocrinology.

Planetary health: protecting human health on a rapidly changing planet.

PubMed

Myers, Samuel S

2018-12-23

The impact of human activities on our planet's natural systems has been intensifying rapidly in the past several decades, leading to disruption and transformation of most natural systems. These disruptions in the atmosphere, oceans, and across the terrestrial land surface are not only driving species to extinction, they pose serious threats to human health and wellbeing. Characterising and addressing these threats requires a paradigm shift. In a lecture delivered to the Academy of Medical Sciences on Nov 13, 2017, I describe the scale of human impacts on natural systems and the extensive associated health effects across nearly every dimension of human health. I highlight several overarching themes that emerge from planetary health and suggest advances in the way we train, reward, promote, and fund the generation of health scientists who will be tasked with breaking out of their disciplinary silos to address this urgent constellation of health threats. I propose that protecting the health of future generations requires taking better care of Earth's natural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Properties and in vitro drug release of hyaluronic acid-hydroxyethyl cellulose hydrogels for transdermal delivery of isoliquiritigenin.

PubMed

Kong, Bong Ju; Kim, Ayoung; Park, Soo Nam

2016-08-20

In the present study, the properties of hydrogel systems based on hyaluronic acid (HA)-hydroxyethyl cellulose (HEC) were investigated for effective transdermal delivery of isoliquiritigenin (ILTG). Hydrogels were synthesized by chemical cross-linking, and network structures were characterised using scanning electron microscopy (SEM) and surface area analyser. Texture properties and swelling of HA-HEC hydrogels were found to be closely linked to cross-linker concentration and swelling medium. Water in HA-HEC hydrogels was found to exist mostly in the form of free water. The viscoelasticity and the network stabilization of the hydrogels were analysed via rheological studies. The release kinetics of the hydrogel followed Fickian diffusion mechanism. In an in vitro skin penetration study, the system substantially improved the delivery of ILTG into the skin. These results indicate that the hydrogel system composed of HA and HEC has potential as a transdermal delivery system, with cross-linking density and the swelling medium influencing the properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cognitive Style, Creativity Framing and Effects

ERIC Educational Resources Information Center

Dew, Robert

2009-01-01

This study investigates how individuals with different cognitive styles respond to choices involving framing effects. The results suggest that cognitive style as defined by Kirton (1976) is far more complex than previous studies indicate. Kirton characterises "Innovators" as rule breakers and "Adaptors" as conformists. The most…

Influence of food intrinsic complexity on Listeria monocytogenes growth in/on vacuum-packed model systems at suboptimal temperatures.

PubMed

Baka, Maria; Noriega, Estefanía; Van Langendonck, Kristof; Van Impe, Jan F

2016-10-17

Food intrinsic factors e.g., food (micro)structure, compositional and physicochemical aspects, which are mutually dependent, influence microbial growth. While the effect of composition and physicochemical properties on microbial growth has been thoroughly assessed and characterised, the role of food (micro)structure still remains unravelled. Most studies on food (micro)structure focus on comparing planktonic growth in liquid (microbiological) media with colonial growth in/on solid-like systems or on real food surfaces. However, foods are not only liquids or solids; they can also be emulsions or gelled emulsions and have complex compositions. In this study, Listeria monocytogenes growth was studied on the whole spectrum of (micro)structure, in terms of food (model) systems. The model systems varied not only in (micro)structure, which was the target of the study, but also in compositional and physicochemical characteristics, which was an inevitable consequence of the (micro)structural variability. The compositional and physicochemical differences were mainly due to the presence or absence of fat and gelling agents. The targeted (micro)structures were: i) liquids, ii) aqueous gels, iii) emulsions and iv) gelled emulsions. Furthermore, the microbial dynamics were studied and compared in/on all these model systems, as well as on a compositionally predefined canned meat, developed in order to have equal compositional level to the gelled emulsion model system and represent a real food system. Frankfurter sausages were the targeted real foods, selected as a case study, to which the canned meat had similar compositional characteristics. All systems were vacuum packed and incubated at 4, 8 and 12°C. The most appropriate protocol for the preparation of the model systems was developed. The pH, water activity and resistance to penetration of the model systems were characterised. Results indicated that low temperature contributes to growth variations among the model systems. Additionally, the firmer the solid system, the faster L. monocytogenes grew on it. Finally, it was found that L. monocytogenes grows faster on canned meat and real Frankfurters, as found in a previous study, followed by liquids, aqueous gels, emulsions and gelled emulsions. This observation indicates that all model systems, developed in this study, underestimated L. monocytogenes growth. Despite some limitations, model systems are overall advantageous and therefore, their validation is always recommended prior to further use. Copyright © 2016. Published by Elsevier B.V.

The use of portable Non-Destructive Techniques for material decay characterisation of palaeontological Geosites

NASA Astrophysics Data System (ADS)

Gomez-Heras, Miguel; Ortega-Becerril, Jose A.; López-Martínez, Jerónimo; Oliva-Urcia, Belén; Maestro, Adolfo

2017-04-01

The conservation of both natural and cultural heritage is regarded as a priority for humankind and it is therefore recognised by the UNESCO since the Convention Concerning the Protection of the World Cultural and Natural Heritage in 1972. The International Union of Geological Sciences launched in 1995 in collaboration with UNESCO the Global Geosites programme to create an inventory of geological heritage sites. Although the conservation of Geosites may face different issues to those of stone-built cultural heritage, much could be learnt from techniques initially used to characterise weathering and material decay in stone-built cultural heritage. This is especially the case for portable Non-Destructive Techniques (NDT). Portable NDT allow characterising on-site the degree of material decay and are, therefore, a good way to assess the state of conservation of certain Geosites whose relevance lies on localised features. Geosites chosen for the outstanding occurrence of dinosaur ichnites, such as those in the Cameros Massif (north-western part of the Iberian Range, Spain), are a good example of this. This communication explores the potential of portable NDT to characterise the state of decay and susceptibility to further decay of dinosaur ichnites in the Cameros Massif. These techniques included: Ultrasound Pulse Velocity determination, Leeb hardness rebound test, colour determination by means of a spectrophotometer and thermal imaging obtained with an infrared camera. Results will show the potential of these techniques to characterise differential weathering patterns in both individual ichnites as well as on tracks in addition to assessing the possible effects of conservation strategies on the long-term preservation of the mentioned Geosites. Research funded by Madrid's Regional Government project Geomateriales 2 S2013/MIT-2914

The application of terahertz pulsed imaging in characterising density distribution of roll-compacted ribbons.

PubMed

Zhang, Jianyi; Pei, Chunlei; Schiano, Serena; Heaps, David; Wu, Chuan-Yu

2016-09-01

Roll compaction is a commonly used dry granulation process in pharmaceutical, fine chemical and agrochemical industries for materials sensitive to heat or moisture. The ribbon density distribution plays an important role in controlling properties of granules (e.g. granule size distribution, porosity and strength). Accurate characterisation of ribbon density distribution is critical in process control and quality assurance. The terahertz imaging system has a great application potential in achieving this as the terahertz radiation has the ability to penetrate most of the pharmaceutical excipients and the refractive index reflects variations in density and chemical compositions. The aim of this study is to explore whether terahertz pulse imaging is a feasible technique for quantifying ribbon density distribution. Ribbons were made of two grades of microcrystalline cellulose (MCC), Avicel PH102 and DG, using a roll compactor at various process conditions and the ribbon density variation was investigated using terahertz imaging and section methods. The density variations obtained from both methods were compared to explore the reliability and accuracy of the terahertz imaging system. An average refractive index is calculated from the refractive index values in the frequency range between 0.5 and 1.5THz. It is shown that the refractive index gradually decreases from the middle of the ribbon towards to the edges. Variations of density distribution across the width of the ribbons are also obtained using both the section method and the terahertz imaging system. It is found that the terahertz imaging results are in excellent agreement with that obtained using the section method, demonstrating that terahertz imaging is a feasible and rapid tool to characterise ribbon density distributions. Copyright © 2016 Elsevier B.V. All rights reserved.

Structural Characterisation of Fenchone and its Complexes with Ethanol by Broadband Rotational Spectroscopy

NASA Astrophysics Data System (ADS)

Loru, Donatella; Sanz, M. Eugenia

2016-06-01

Although significant advances in understanding the human olfactory system have taken place over the last two decades, detailed information on how the interactions between odorants and olfactory receptors occur at the molecular level is still lacking. To achieve a better understanding on the molecular mechanisms involved in olfaction, we are investigating several odorants and their interactions with mimics of amino acid residues in olfactory receptors. We present here the structural characterisation of fenchone (C10H16O) and its complexes with ethanol (to mimic the side chain of serine) using a 2-8 GHz chirped-pulse Fourier transform microwave spectrometer built at King's College London. The rotational spectrum of the parent species and all the 13C and 18O isotopologues of fenchone was observed, and from the experimental rotational constants the substitution (r0) and effective (rs) structures of fenchone were determined. The rotational spectrum of fenchone-ethanol was observed by adding ethanol to the carrier gas and passing the mixture through a receptacle with fenchone. Several 1:1 complexes of fenchone-ethanol have been identified in the rotational spectrum. In all the complexes the ethanol molecule binds to the carbonyl group through an O-H· · · O hydrogen bond.

Epidemic yellow fever in Borno State of Nigeria: characterisation of hospitalised patients.

PubMed

Ekenna, O; Chikwem, J O; Mohammed, I; Durojaiye, S O

2010-01-01

In 1990, an outbreak of a febrile illness with high mortality was reported in border villages, later spreading to other areas of Borno State of Nigeria. To present a report of the investigation of that outbreak, with emphasis on the characterisation of hospitalised patients. Selected centres reporting cases of acute febrile illness during the months of August to December, 1990 were visited, to establish surveillance. Case investigation forms were used to obtain clinical and demographic data; and blood samples were obtained from patients for analyses. Only hospitalised patients with adequate clinical information from three centres were included in the analysis. The outbreak, which involved five of the six health zones in the state, and spread into adjoining Gongola state and the Cameroun Republic, was caused by the yellow fever virus. Fever, central nervous system (CNS) involvement, jaundice and haemorrhage were the most common clinical manifestations of 102 hospitalised patients. Eighty -three (81%) of hospitalised patients died and most within two days of admission. CNS manifestations were more common in dying patients than in survivors. The reasons for this rare outbreak of yellow fever in the dry Savannah belt of Borno State remain unclear. Improved surveillance and more effective prevention strategies are needed to avert the recurrence of such outbreaks.

Spectroscopic Characterisation of CARMENES Target Candidates from FEROS, CAFE and HRS High-Resolution Spectra

NASA Astrophysics Data System (ADS)

Passegger, Vera Maria; Reiners, Ansgar; Jeffers, Sandra V.; Wende, Sebastian; Schöfer, Patrick; Amado, Pedro J.; Caballero, Jose A.; Montes, David; Mundt, Reinhard; Ribas, Ignasi; Quirrenbach, Andreas

2016-07-01

CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) started a new planet survey on M-dwarfs in January this year. The new high-resolution spectrographs are operating in the visible and near-infrared at Calar Alto Observatory. They will perform high-accuracy radial-velocity measurements (goal 1 m s-1) of about 300 M-dwarfs with the aim to detect low-mass planets within habitable zones. We characterised the candidate sample for CARMENES and provide fundamental parameters for these stars in order to constrain planetary properties and understand star-planet systems. Using state-of-the-art model atmospheres (PHOENIX-ACES) and χ2-minimization with a downhill-simplex method we determine effective temperature, surface gravity and metallicity [Fe/H] for high-resolution spectra of around 480 stars of spectral types M0.0-6.5V taken with FEROS, CAFE and HRS. We find good agreement between the models and our observed high-resolution spectra. We show the performance of the algorithm, as well as results, parameter and spectral type distributions for the CARMENES candidate sample, which is used to define the CARMENES target sample. We also present first preliminary results obtained from CARMENES spectra.

Water in HD209458b's atmosphere from 3.6 -8 microns IRAC photometric observations in primary transit

NASA Astrophysics Data System (ADS)

Campanella, Giammarco; Beaulieu, J. P.; Kipping, D. M.; Batista, V.; Tinetti, G.; Ribas, I.; Carey, S.; Noriega-Crespo, J. A.; Griffith, C. A.; Dong, S.; Tennyson, J.; Barber, R. J.; Deroo, P.; Fossey, S. J.; Liang, D.; Swain, M. R.; Yung, Y.; Allard, N.

Since planets were first discovered outside our own Solar System in 1992 (around a pulsar) and in 1995 (around a main sequence star), extrasolar planet studies have become one of the most dynamic research fields in astronomy. Now that more than 400 exoplanets have been discovered, focus has moved from finding planets to characterise these alien worlds. Part of the characterisation process undoubtedly involves the detection of the atmospheres of these exoplanets. We describe the primary transit observations of the hot Jupiter HD 209458b we obtained at 3.6, 4.5, 5.8 and 8.0 µm using the Infrared Array Camera on the Spitzer Space Telescope. We detail the procedures we adopted to correct for the systematic trends present in IRAC data. The lightcurves were fitted, taking into account limb darkening effects, using Markov Chain Monte Carlo and prayer-bead Monte Carlo techniques. We obtained the following depth measurements: at 3.6 µm, 1.469±0.013 % and 1.448±0.013 %; at 4.5 µm, 1.478±0.017 %; at 5.8 µm, 1.549±0.015 % and at 8.0 µm 1.535±0.011 %. Our results indicate the presence of water in the planetary atmosphere.

A tuneable approach to uniform light distribution for artificial daylight photodynamic therapy.

PubMed

O'Mahoney, Paul; Haigh, Neil; Wood, Kenny; Brown, C Tom A; Ibbotson, Sally; Eadie, Ewan

2018-06-16

Implementation of daylight photodynamic therapy (dPDT) is somewhat limited by variable weather conditions. Light sources have been employed to provide artificial dPDT indoors, with low irradiances and longer treatment times. Uniform light distribution across the target area is key to ensuring effective treatment, particularly for large areas. A novel light source is developed with tuneable direction of light emission in order to meet this challenge. Wavelength composition of the novel light source is controlled such that the protoporphyrin-IX (PpIX) weighed spectra of both the light source and daylight match. The uniformity of the light source is characterised on a flat surface, a model head and a model leg. For context, a typical conventional PDT light source is also characterised. Additionally, the wavelength uniformity across the treatment site is characterised. The PpIX-weighted spectrum of the novel light source matches with PpIX-weighted daylight spectrum, with irradiance values within the bounds for effective dPDT. By tuning the direction of light emission, improvements are seen in the uniformity across large anatomical surfaces. Wavelength uniformity is discussed. We have developed a light source that addresses the challenges in uniform, multiwavelength light distribution for large area artificial dPDT across curved anatomical surfaces. Copyright © 2018. Published by Elsevier B.V.

Object strength--an accurate measure for small objects that is insensitive to partial volume effects.

PubMed

Tofts, P S; Silver, N C; Barker, G J; Gass, A

2005-07-01

There are currently four problems in characterising small nonuniform lesions or other objects in Magnetic Resonance images where partial volume effects are significant. Object size is over- or under-estimated; boundaries are often not reproducible; mean object value cannot be measured; and fuzzy borders cannot be accommodated. A new measure, Object Strength, is proposed. This is the sum of all abnormal intensities, above a uniform background value. For a uniform object, this is simply the product of the increase in intensity and the size of the object. Biologically, this could be at least as relevant as existing measures of size or mean intensity. We hypothesise that Object Strength will perform better than traditional area measurements in characterising small objects. In a pilot study, the reproducibility of object strength measurements was investigated using MR images of small multiple sclerosis (MS) lesions. In addition, accuracy was investigated using artificial lesions of known volume (0.3-6.2 ml) and realistic appearance. Reproducibility approached that of area measurements (in 33/90 lesion reports the difference between repeats was less than for area measurements). Total lesion volume was accurate to 0.2%. In conclusion, Object Strength has potential for improved characterisation of small lesions and objects in imaging and possibly spectroscopy.

H∞ filtering for discrete-time systems subject to stochastic missing measurements: a decomposition approach

NASA Astrophysics Data System (ADS)

Gu, Zhou; Fei, Shumin; Yue, Dong; Tian, Engang

2014-07-01

This paper deals with the problem of H∞ filtering for discrete-time systems with stochastic missing measurements. A new missing measurement model is developed by decomposing the interval of the missing rate into several segments. The probability of the missing rate in each subsegment is governed by its corresponding random variables. We aim to design a linear full-order filter such that the estimation error converges to zero exponentially in the mean square with a less conservatism while the disturbance rejection attenuation is constrained to a given level by means of an H∞ performance index. Based on Lyapunov theory, the reliable filter parameters are characterised in terms of the feasibility of a set of linear matrix inequalities. Finally, a numerical example is provided to demonstrate the effectiveness and applicability of the proposed design approach.

Assessment of sensor performance

NASA Astrophysics Data System (ADS)

Waldmann, C.; Tamburri, M.; Prien, R. D.; Fietzek, P.

2010-02-01

There is an international commitment to develop a comprehensive, coordinated and sustained ocean observation system. However, a foundation for any observing, monitoring or research effort is effective and reliable in situ sensor technologies that accurately measure key environmental parameters. Ultimately, the data used for modelling efforts, management decisions and rapid responses to ocean hazards are only as good as the instruments that collect them. There is also a compelling need to develop and incorporate new or novel technologies to improve all aspects of existing observing systems and meet various emerging challenges. Assessment of Sensor Performance was a cross-cutting issues session at the international OceanSensors08 workshop in Warnemünde, Germany, which also has penetrated some of the papers published as a result of the workshop (Denuault, 2009; Kröger et al., 2009; Zielinski et al., 2009). The discussions were focused on how best to classify and validate the instruments required for effective and reliable ocean observations and research. The following is a summary of the discussions and conclusions drawn from this workshop, which specifically addresses the characterisation of sensor systems, technology readiness levels, verification of sensor performance and quality management of sensor systems.

Commissioning of inline ECE system within waveguide based ECRH transmission systems on ASDEX upgrade

NASA Astrophysics Data System (ADS)

Bongers, W. A.; Kasparek, W.; Doelman, N.; van den Braber, R.; van den Brand, H.; Meo, F.; de Baar, M. R.; Amerongen, F. J.; Donné, A. J. H.; Elzendoorn, B. S. Q.; Erckmann, V.; Goede, A. P. H.; Giannone, L.; Grünwald, G.; Hollman, F.; Kaas, G.; Krijger, B.; Michel, G.; Lubyako, L.; Monaco, F.; Noke, F.; Petelin, M.; Plaum, B.; Purps, F.; ten Pierik, J. G. W.; Schüller, C.; Slob, J. W.; Stober, J. K.; Schütz, H.; Wagner, D.; Westerhof, E.; Ronden, D. M. S.

2012-09-01

A CW capable inline electron cyclotron emission (ECE) separation system for feedback control, featuring oversized corrugated waveguides, is commissioned on ASDEX upgrade (AUG). The system is based on a combination of a polarization independent, non-resonant, Mach-Zehnder diplexer equipped with dielectric plate beam splitters [2, 3] employed as corrugated oversized waveguide filter, and a resonant Fast Directional Switch, FADIS [4, 5, 6, 7] as ECE/ECCD separation system. This paper presents an overview of the system, the low power characterisation tests and first high power commissioning on AUG.

The effects of mineral aerosol deposits on the BRDF (bidirectional reflectance distribution function) of sea ice for the calibration of satellite remote sensing products: an experimental and modelling study.

NASA Astrophysics Data System (ADS)

Lamare, Maxim; Hedley, John; King, Martin

2016-04-01

Knowledge of the albedo in the cryosphere is essential to monitor a range of climatic processes that have an impact on a global scale. Optical Earth Observation satellites are ideal for the synoptic observation of expansive and inaccessible areas, providing large datasets used to derive essential products, such as albedo. The application of remote sensing to investigate climate processes requires the combination of data from different sensors. However, although there is significant value in the analysis of data from individual sensors, global observing systems require accurate knowledge of sensor-to-sensor biases. Therefore, the inter-calibration of sensors used for climate studies is essential to avoid inconsistencies, which may mask climate effects. CEOS (Committee on Earth Observing Satellites) has established a number of natural Earth targets to serve as international reference standards, amongst which sea ice has great potential. The reflectance of natural surfaces is not isotropic and reflectance varies with the illumination and viewing geometries, consequently impacting satellite observations. Furthermore, variations in the physical properties (sea ice type, thickness) and the light absorbing impurities deposited in the sea ice have a strong impact on reflectance. Thus, the characterisation of the bi-directional reflectance distribution function (BRDF) of sea ice is a fundamental step toward the inter-calibration of optical satellite sensors. This study provides a characterisation of the effects of mineral aerosol and black carbon deposits on the BRDF of three different sea ice types. BRDF measurements were performed on bare sea ice grown in an experimental ice tank, using a state-of-the-art laboratory goniometer. The sea ice was "poisoned" with concentrations of mineral dust and black carbon varying between 100 and 5 000 ng g-1 deposited uniformly in a 5 cm surface layer. Using measurements from the experimental facility, novel information about sea ice BRDF as a function of sea ice type, thickness and light-absorbing impurities was derived using a radiative-transfer model (PlanarRad). This extensive characterisation of the multi angular reflectance of sea ice reveals the importance of BRDF for the validation and calibration of Earth Observation satellite sensor data.

Geological exploration for a high-temperature aquifer thermal energy storage (HT-ATES) system: a case study from Oman

NASA Astrophysics Data System (ADS)

Winterleitner, Gerd; Schütz, Felina; Huenges, Ernst

2017-04-01

A collaborative research programme between the German Research Centre for Geoscience, Potsdam (GFZ) and The Research Council of Oman (TRC) is underway, which aims to develop and implement an innovative concept of a sustainable thermally driven cooling system in combination with a HT-ATES in northern Oman. The system will use an absorption chiller for cold supply, which nominally requires water of around 100°C as energy source. Solar collectors will provide this thermal energy and energy surpluses during daytimes will be stored to ensure a continuous operation of the cooling system. An integral part of this project is, therefore, the development of an efficient HT-ATES (100°C), which is based on temporary storage and recovery of thermal energy through hot water injection in subsurface aquifer horizons. Thus, an accurate thermal and fluid flow characterisation of potential reservoir horizons is essential to ensure optimal efficiency of the cooling system. The study area is located in the Al Khwad area, approximately 40 km to the west of Muscat. The area is characterised by a thick Cenozoic mixed carbonate-siliciclastic sedimentary succession, containing at least 3 aquifer horizons. We use a multidisciplinary approach for the initial ATES exploration and development phase, including traditional geological fieldwork dovetailed with virtual outcrop geology, thin-section analyses, geological modelling and reservoir fluid flow forecasting analyses. Our first results indicate two potential storage horizons: (1) a Miocene-aged clastic-dominated alluvial fan system and (2) an Eocene carbonate-dominated sequence. The alluvial fan system is characterised by a more than 300 m thick, coarse-clastic succession of coalesced individual fans. Thermal and hydraulic parameters are favourable for gravel and sandstone intervals but reservoir architecture is complex due to multiple generations of interconnecting fans with highly heterogeneous facies distributions. The Eocene carbonates, as second potential storage horizon, were deposited in a carbonate ramp setting. Individual facies belts extend over kilometres and thus horizontal reservoir connectivity is expected to be good with minor facies variability. Thin-section analyses point to the fossil-rich sections with high porosities and permeabilities and thus good storage qualities. Fluid flow and thermal modelling indicate that both potential storage horizons show good to very good storage characteristics but also have challenges such as reservoir heterogeneity and connectivity. In particular the tilting of the thermocline, specific to high-temperature systems poses a major challenge. We investigated scenarios to counterbalance the distortion of the subsurface heat-plume, which includes adjustments of the salinity contrast between injected and aquifer fluid to prohibit buoyancy-driven flow. Additionally, geological structures ("HT-ATES traps" e.g.: fault structures) were modelled in detail in order to analyse their suitability as high-temperature storage system. First results show that an effective HT-ATES trap is necessary in the alluvial fan system in order to keep in control of the heat-plume. Salinity adjustments are sufficient in the carbonate-dominated sequences where vertical permeability contrasts are higher and constitute natural vertical flow barriers.

The Illusory Dichotomy of Plagiarism

ERIC Educational Resources Information Center

Stuhmcke, Anita; Booth, Tracey; Wangmann, Jane

2016-01-01

Plagiarism has been characterised as a "major problem" for universities. While tensions between students and universities are inevitable, the problem with the existing system of plagiarism management and prevention is that it operates to problematise the relationship between the university and the student, rather than address the core…

On-ground and in-orbit characterisation plan for the PLATO CCD normal cameras

NASA Astrophysics Data System (ADS)

Gow, J. P. D.; Walton, D.; Smith, A.; Hailey, M.; Curry, P.; Kennedy, T.

2017-11-01

PLAnetary Transits and Ocillations (PLATO) is the third European Space Agency (ESA) medium class mission in ESA's cosmic vision programme due for launch in 2026. PLATO will carry out high precision un-interrupted photometric monitoring in the visible band of large samples of bright solar-type stars. The primary mission goal is to detect and characterise terrestrial exoplanets and their systems with emphasis on planets orbiting in the habitable zone, this will be achieved using light curves to detect planetary transits. PLATO uses a novel multi- instrument concept consisting of 26 small wide field cameras The 26 cameras are made up of a telescope optical unit, four Teledyne e2v CCD270s mounted on a focal plane array and connected to a set of Front End Electronics (FEE) which provide CCD control and readout. There are 2 fast cameras with high read-out cadence (2.5 s) for magnitude ~ 4-8 stars, being developed by the German Aerospace Centre and 24 normal (N) cameras with a cadence of 25 s to monitor stars with a magnitude greater than 8. The N-FEEs are being developed at University College London's Mullard Space Science Laboratory (MSSL) and will be characterised along with the associated CCDs. The CCDs and N-FEEs will undergo rigorous on-ground characterisation and the performance of the CCDs will continue to be monitored in-orbit. This paper discusses the initial development of the experimental arrangement, test procedures and current status of the N-FEE. The parameters explored will include gain, quantum efficiency, pixel response non-uniformity, dark current and Charge Transfer Inefficiency (CTI). The current in-orbit characterisation plan is also discussed which will enable the performance of the CCDs and their associated N-FEE to be monitored during the mission, this will include measurements of CTI giving an indication of the impact of radiation damage in the CCDs.

Systematic development of design of experiments (DoE) optimised self-microemulsifying drug delivery system of Zotepine.

PubMed

Dalvadi, Hitesh; Patel, Nikita; Parmar, Komal

2017-05-01

The aim of present investigation is to improve dissolution rate of poor soluble drug Zotepine by a self-microemulsifying drug delivery system (SMEDDS). Ternary phase diagram with oil (Oleic acid), surfactant (Tween 80) and co-surfactant (PEG 400) at apex were used to identify the efficient self-microemulsifying region. Box-Behnken design was implemented to study the influence of independent variables. Principal Component Analysis was used for scrutinising critical variables. The liquid SMEDDS were characterised for macroscopic evaluation, % Transmission, emulsification time and in vitro drug release studies. Optimised formulation OL1 was converted in to S-SMEDDS by using Aerosil ® 200 as an adsorbent in the ratio of 3:1. The S-SMEDDS was characterised by SEM, DSC, globule size (152.1 nm), zeta-potential (-28.1 mV), % transmission study (98.75%), in vitro release (86.57%) at 30 min. The optimised solid SMEDDS formulation showed faster drug release properties as compared to conventional tablet of Zotepine.

Characterisation of the high dynamic range Large Pixel Detector (LPD) and its use at X-ray free electron laser sources

DOE PAGES

Veale, M. C.; Adkin, P.; Booker, P.; ...

2017-12-04

The STFC Rutherford Appleton Laboratory have delivered the Large Pixel Detector (LPD) for MHz frame rate imaging at the European XFEL. The detector system has an active area of 0.5 m × 0.5 m and consists of a million pixels on a 500 μm pitch. Sensors have been produced from 500 μm thick Hammamatsu silicon tiles that have been bump bonded to the readout ASIC using a silver epoxy and gold stud technique. Each pixel of the detector system is capable of measuring 10 5 12 keV photons per image readout at 4.5 MHz. In this paper results from themore » testing of these detectors at the Diamond Light Source and the Linac Coherent Light Source (LCLS) are presented. As a result, the performance of the detector in terms of linearity, spatial uniformity and the performance of the different ASIC gain stages is characterised.« less

Characterisation of the high dynamic range Large Pixel Detector (LPD) and its use at X-ray free electron laser sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veale, M. C.; Adkin, P.; Booker, P.

The STFC Rutherford Appleton Laboratory have delivered the Large Pixel Detector (LPD) for MHz frame rate imaging at the European XFEL. The detector system has an active area of 0.5 m × 0.5 m and consists of a million pixels on a 500 μm pitch. Sensors have been produced from 500 μm thick Hammamatsu silicon tiles that have been bump bonded to the readout ASIC using a silver epoxy and gold stud technique. Each pixel of the detector system is capable of measuring 10 5 12 keV photons per image readout at 4.5 MHz. In this paper results from themore » testing of these detectors at the Diamond Light Source and the Linac Coherent Light Source (LCLS) are presented. As a result, the performance of the detector in terms of linearity, spatial uniformity and the performance of the different ASIC gain stages is characterised.« less

Microbial enhancement of compost extracts based on cattle rumen content compost - characterisation of a system.

PubMed

Shrestha, Karuna; Shrestha, Pramod; Walsh, Kerry B; Harrower, Keith M; Midmore, David J

2011-09-01

Microbially enhanced compost extracts ('compost tea') are being used in commercial agriculture as a source of nutrients and for their perceived benefit to soil microbiology, including plant disease suppression. Rumen content material is a waste of cattle abattoirs, which can be value-added by conversion to compost and 'compost tea'. A system for compost extraction and microbial enhancement was characterised. Molasses amendment increased bacterial count 10-fold, while amendment based on molasses and 'fish and kelp hydrolysate' increased fungal count 10-fold. Compost extract incubated at 1:10 (w/v) dilution showed the highest microbial load, activity and humic/fulvic acid content compared to other dilutions. Aeration increased the extraction efficiency of soluble metabolites, and microbial growth rate, as did extraction of compost without the use of a constraining bag. A protocol of 1:10 dilution and aerated incubation with kelp and molasses amendments is recommended to optimise microbial load and fungal-to-bacterial ratio for this inoculum source. Copyright © 2011 Elsevier Ltd. All rights reserved.

Identification and characterisation of isoprene-degrading bacteria in an estuarine environment.

PubMed

Johnston, Antonia; Crombie, Andrew T; El Khawand, Myriam; Sims, Leanne; Whited, Gregg M; McGenity, Terry J; Colin Murrell, J

2017-09-01

Approximately one-third of volatile organic compounds (VOCs) emitted to the atmosphere consists of isoprene, originating from the terrestrial and marine biosphere, with a profound effect on atmospheric chemistry. However, isoprene provides an abundant and largely unexplored source of carbon and energy for microbes. The potential for isoprene degradation in marine and estuarine samples from the Colne Estuary, UK, was investigated using DNA-Stable Isotope Probing (DNA-SIP). Analysis at two timepoints showed the development of communities dominated by Actinobacteria including members of the genera Mycobacterium, Rhodococcus, Microbacterium and Gordonia. Representative isolates, capable of growth on isoprene as sole carbon and energy source, were obtained from marine and estuarine locations, and isoprene-degrading strains of Gordonia and Mycobacterium were characterised physiologically and their genomes were sequenced. Genes predicted to be required for isoprene metabolism, including four-component isoprene monooxygenases (IsoMO), were identified and compared with previously characterised examples. Transcriptional and activity assays of strains growing on isoprene or alternative carbon sources showed that growth on isoprene is an inducible trait requiring a specific IsoMO. This study is the first to identify active isoprene degraders in estuarine and marine environments using DNA-SIP and to characterise marine isoprene-degrading bacteria at the physiological and molecular level. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Can Schools Be Autonomous in a Centralised Educational System?: On Formal and Actual School Autonomy in the Italian Context

ERIC Educational Resources Information Center

Agasisti, Tommaso; Catalano, Giuseppe; Sibiano, Piergiacomo

2013-01-01

Purpose: The purpose of this paper is to examine the difference between formal and real school autonomy in the Italian educational system. The Italian case is characterised by low levels of school autonomy. It is interesting to consider whether heterogeneity of patterns is possible in this context. A description of this heterogeneity is provided…

Effect of crystallographic orientation on the anodic formation of nanoscale pores/tubes in TiO 2 films

NASA Astrophysics Data System (ADS)

Kalantar-zadeh, K.; Sadek, A. Z.; Zheng, H.; Partridge, J. G.; McCulloch, D. G.; Li, Y. X.; Yu, X. F.; Wlodarski, W.

2009-10-01

Self-organized nanopores and nanotubes have been produced in thin films of titanium (Ti) prepared using filtered cathodic vacuum arc (FCVA), DC- and RF-sputter deposition systems. The anodization process was performed using a neutral electrolyte containing fluoride ions with an applied potential between 2 and 20 V (for clarity the results are only presented for 5 V). Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques were used to characterise the films. It was found that the crystallographic orientation of the Ti films played a significant role in determining whether pores or tubes were formed during the anodic etching process.

Equity - some theory and its policy implications.

PubMed

Culyer, A J

2001-08-01

This essay seeks to characterise the essential features of an equitable health care system in terms of the classical Aristotelian concepts of horizontal and vertical equity, the common (but ill-defined) language of "need" and the economic notion of cost-effectiveness as a prelude to identifying some of the more important issues of value that policy-makers will have to decide for themselves; the characteristics of health (and what determines it) that can cause policy to be ineffective (or have undesired consequences); the information base that is required to support a policy directed at securing greater equity, and the kinds of research (theoretical and empirical) that are needed to underpin such a policy.

Deep dysgraphia in Turkish.

PubMed

Raman, Ilhan; Weekes, Brendan Stuart

2005-01-01

Deep dysgraphic patients make semantic errors when writing to dictation and they cannot write nonwords. Extant reports of deep dysgraphia come from languages with relatively opaque orthographies. Turkish is a transparent orthography because the bidirectional mappings between phonology and orthography are completely predictable. We report BRB, a biscriptal Turkish-English speaker who has acquired dysgraphia characterised by semantic errors as well as effects of grammatical class and imageability on writing in Turkish. Nonword spelling is abolished. A similar pattern of errors is observed in English. BRB is the first report of acquired dysgraphia in a truly transparent writing system. We argue that deep dysgraphia results from damage to the mappings that are common to both languages between word meanings and orthographic representations.

Measurement and modelling of reactive transport in geological barriers for nuclear waste containment

DOE PAGES

Xiong, Qingrong; Joseph, Claudia; Schmeide, Katja; ...

2015-10-26

Compacted clays are considered as excellent candidates for barriers to radionuclide transport in future repositories for nuclear waste due to their very low hydraulic permeability. Diffusion is the dominant transport mechanism, controlled by a nano-scale pore system. Assessment of the clays' long-term containment function requires adequate modelling of such pore systems and their evolution. Existing characterisation techniques do not provide complete pore space information for effective modelling, such as pore and throat size distributions and connectivity. Special network models for reactive transport are proposed here using the complimentary character of the pore space and the solid phase. Here, this balancesmore » the insufficient characterisation information and provides the means for future mechanical–physical–chemical coupling. The anisotropy and heterogeneity of clays is represented using different length parameters and percentage of pores in different directions. Resulting networks are described as mathematical graphs with efficient discrete calculus formulation of transport. Opalinus Clay (OPA) is chosen as an example. Experimental data for the tritiated water (HTO) and U(VI) diffusion through OPA are presented. Calculated diffusion coefficients of HTO and uranium species are within the ranges of the experimentally determined data in different clay directions. This verifies the proposed pore network model and validates that uranium complexes are diffusing as neutral species in OPA. In the case of U(VI) diffusion the method is extended to account for sorption and convection. Finally, rather than changing pore radii by coarse grained mathematical formula, physical sorption is simulated in each pore, which is more accurate and realistic.« less

Measurement and modelling of reactive transport in geological barriers for nuclear waste containment.

PubMed

Xiong, Qingrong; Joseph, Claudia; Schmeide, Katja; Jivkov, Andrey P

2015-11-11

Compacted clays are considered as excellent candidates for barriers to radionuclide transport in future repositories for nuclear waste due to their very low hydraulic permeability. Diffusion is the dominant transport mechanism, controlled by a nano-scale pore system. Assessment of the clays' long-term containment function requires adequate modelling of such pore systems and their evolution. Existing characterisation techniques do not provide complete pore space information for effective modelling, such as pore and throat size distributions and connectivity. Special network models for reactive transport are proposed here using the complimentary character of the pore space and the solid phase. This balances the insufficient characterisation information and provides the means for future mechanical-physical-chemical coupling. The anisotropy and heterogeneity of clays is represented using different length parameters and percentage of pores in different directions. Resulting networks are described as mathematical graphs with efficient discrete calculus formulation of transport. Opalinus Clay (OPA) is chosen as an example. Experimental data for the tritiated water (HTO) and U(vi) diffusion through OPA are presented. Calculated diffusion coefficients of HTO and uranium species are within the ranges of the experimentally determined data in different clay directions. This verifies the proposed pore network model and validates that uranium complexes are diffusing as neutral species in OPA. In the case of U(vi) diffusion the method is extended to account for sorption and convection. Rather than changing pore radii by coarse grained mathematical formula, physical sorption is simulated in each pore, which is more accurate and realistic.

Simple, quick and cost-efficient: A universal RT-PCR and sequencing strategy for genomic characterisation of foot-and-mouth disease viruses.

PubMed

Dill, V; Beer, M; Hoffmann, B

2017-08-01

Foot-and-mouth disease (FMD) is a major contributor to poverty and food insecurity in Africa and Asia, and it is one of the biggest threats to agriculture in highly developed countries. As FMD is extremely contagious, strategies for its prevention, early detection, and the immediate characterisation of outbreak strains are of great importance. The generation of whole-genome sequences enables phylogenetic characterisation, the epidemiological tracing of virus transmission pathways and is supportive in disease control strategies. This study describes the development and validation of a rapid, universal and cost-efficient RT-PCR system to generate genome sequences of FMDV, reaching from the IRES to the end of the open reading frame. The method was evaluated using twelve different virus strains covering all seven serotypes of FMDV. Additionally, samples from experimentally infected animals were tested to mimic diagnostic field samples. All primer pairs showed a robust amplification with a high sensitivity for all serotypes. In summary, the described assay is suitable for the generation of FMDV sequences from all serotypes to allow immediate phylogenetic analysis, detailed genotyping and molecular epidemiology. Copyright © 2017 Elsevier B.V. All rights reserved.

Time-lapse Seismic Refraction Monitoring of an Active Landslide in Lias Group Mudrocks, North Yorkshire, UK

NASA Astrophysics Data System (ADS)

Uhlemann, S.; Whiteley, J.; Chambers, J. E.; Inauen, C.; Swift, R. T.

2017-12-01

Geophysical monitoring of the internal moisture content and processes of landslides is an increasingly common approach to the characterisation and assessment of the hydrogeological condition of rainfall-triggered landslides. Geoelectrical monitoring methods are sensitive to changes in the subsurface moisture conditions that cause the failure of unstable slopes, typically through the increase of pore water pressures and softening of materials within the landslide system. The application of seismic methods to the monitoring of landslides has not been as extensively applied as geoelectrical approaches, but the seismic method can determine elastic properties of landslide materials that can characterise and identify changes in the geomechanical condition of landslide systems that also lead to slope failure. We present the results of a seismic refraction monitoring campaign undertaken at the Hollin Hill Landslide Observatory in North Yorkshire, UK. This campaign has involved the repeat acquisition of surface acquired high resolution P- and S-wave seismic refraction data. The monitoring profile traverses a 142m long section from the crest to the toe of an active landslide comprising of mudstone and sandstone. Data were acquired at six to nine week intervals between October 2016 and October 2017. This repeat acquisition approach allowed for the imaging of seismically determined property changes of the landslide throughout the annual climatic cycle. Initial results showed that changes in the moisture dynamics of the landslide are reflected by changes in the seismic character of the inverted tomograms. Changes in the seismic properties are linked to the changes in the annual climatic cycle, particularly in relation to effective rainfall. The results indicate that the incorporation of seismic monitoring data into ongoing geoelectrical monitoring programmes can provide complementary geomechanical data to enhance our understanding of the internal condition of landslide systems. Future development of this integrated approach will allow for the imaging and monitoring of these systems at unprecedented spatial and temporal scales.

In vitro and ex vivo characterisation of an in situ gelling formulation for sustained lidocaine release with potential use following knee arthroplasty.

PubMed

Sharma, Manisha; Chandramouli, Kaushik; Curley, Louise; Pontre, Beau; Reilly, Keryn; Munro, Jacob; Hill, Andrew; Young, Simon; Svirskis, Darren

2018-06-01

Sustained lidocaine release via a thermoresponsive poloxamer-based in situ gelling system has the potential to alleviate pain following knee arthroplasty. A previously developed formulation showed a promising drug release profile in synthetic phosphate-buffered saline (PBS). To support the translation of this formulation, ex vivo characterisation was warranted. This study therefore aimed (1) to modify the previously developed formulation to reduce the burst release, (2) to compare the release behaviour into ex vivo human intra-articular fluid (IAF) and PBS and (3) to determine the formulation spread in an ex vivo human knee using magnetic resonance imaging (MRI). All formulations provided sustained release out to 72 h; polyvinyl pyrrolidone was the most effective additive yielding a small yet significant decrease (p < 0.05) in the burst release. Release of lidocaine from the formulation occurred significantly faster into IAF compared to PBS (1.4 times greater release in the first 24 h), correlating with faster rates of gel erosion in IAF. Injection was easily achieved through a 21-gauge (G) needle into the synovial space of a human cadaveric knee, and MRI scans revealed effective spreading of the formulation throughout the joint cavity. The pattern of spread is promising for the drug to reach the widespread nerve endings in the joint capsule; the effect of this spread on release in an in vivo setting will be the subject of future studies. The demonstrated properties indicate that the in situ gelling formulation has the potential to be used clinically to treat post-operative pain following knee arthroplasty.

Educational Leadership as Best Practice in Highly Effective Schools in the Autonomous Region of the Basque County (Spain)

ERIC Educational Resources Information Center

Intxausti, Nahia; Joaristi, Luis; Lizasoain, Luis

2016-01-01

This study presents part of a research project currently underway which aims to characterise the best practices of highly effective schools in the Autonomous Region of the Basque Country (Spain). Multilevel statistical modelling and hierarchical linear models were used to select 32 highly effective schools, with highly effective being taken to…

Effects of unsteady conditions on propulsion generated by the hand's motion in swimming: a systematic review.

PubMed

Gomes, Lara Elena; Loss, Jefferson Fagundes

2015-01-01

The understanding of swimming propulsion is a key factor in the improvement of performance in this sport. Propulsive forces have been quantified under steady conditions since the 1970s, but actual swimming involves unsteady conditions. Thus, the purpose of the present article was to review the effects of unsteady conditions on swimming propulsion based on studies that have compared steady and unsteady conditions while exploring their methods, their limitations and their results, as well as encouraging new studies based on the findings of this systematic review. A multiple database search was performed, and only those studies that met all eligibility criteria were included. Six studies that compared steady and unsteady conditions using physical experiments or numerical simulations were selected. The selected studies verified the effects of one or more factors that characterise a condition as unsteady on the propulsive forces. Consequently, much research is necessary to understand the effect of each individual variable that characterises a condition as unsteady on swimming propulsion, as well as the effects of these variables as a whole on swimming propulsion.

Multiplicative Thinking: Much More than Knowing Multiplication Facts and Procedures

ERIC Educational Resources Information Center

Hurst, Chris; Hurrell, Derek

2016-01-01

Multiplicative thinking is accepted as a "big idea" of mathematics that underpins important mathematical concepts such as fraction understanding, proportional reasoning, and algebraic thinking. It is characterised by understandings such as the multiplicative relationship between places in the number system, basic and extended number…

Intercultural Education and the Crisis of Globalisation: Some Reflections

ERIC Educational Resources Information Center

Coulby, David

2011-01-01

In this essay I reflect on the role of intercultural education in an emerging global crisis. Education systems are characterised by both divergent and convergent impulses. Divergent impulses include tradition, nationalism and religion. Convergent impulses (isomorphism) include science and technology, culture (including the English language),…

Educational Ambassadors in the Danish Trade Union Movement

ERIC Educational Resources Information Center

Keil, Michael

2008-01-01

The concept of Educational Ambassadors is embedded within the so-called "Danish model" of industrial relations. The Danish industrial relations system is characterised by strong collective organisations with national coverage, which conclude the collective agreements for various industries or sectors and which are mostly grouped under…

Automated systems to monitor space radiation effect on photosynthetic organisms

NASA Astrophysics Data System (ADS)

Esposito, D.; di Costa, F.; Faraloni, C.; Fasolo, F.; Pace, E.; Perosino, M.; Torzillo, G.; Touloupakis, E.; Zanini, A.; Giardi, M. T.

We developed automated biodevices to obtain, automatically, measures about the space radiation effect on living photosynthetic organisms, which can be used as biomass and oxygen-producing system on shuttles or ISS. Vitality measurements were performed by optical devices (fluorimeters) measuring fluorescence emission. Fluorescence methodology is a well known applied technique for studying photosynthetic activity, and in particular the oxygen-evolving process of photosynthetic organisms. Different strains of unicellular green algae are properly immobilized on agar growth medium and kept under survial light. The biodevices are characterised by the sensibility and selectivity of the biological component response, together with easy use, versatility, miniature size and low cost. We performed experiments in some facilities, in order to understand separately the effect of radiation of different LET, on the biochemical activity (gamma rays at Joint Research Centre -Varese, Italy; fast neutrons at CERF -- SPS beam at CERN -Geneva, Switzerland). The exposure to different radiation beams of the automatic devices, allowed us to test them under stress condition. In one year, these instrument are expected to be sent to space, inside a spacecraft, in order to study the effect of ionising cosmic radiation during an ESA flight.

Fuel accumulation and forest structure change following hazardous fuel reduction treatments throughout California

Treesearch

Nicole M. Vaillant; Erin K. Noonan-Wright; Alicia L. Reiner; Carol M. Ewell; Benjamin M. Rau; Josephine A. Fites-Kaufman; Scott N. Dailey

2015-01-01

Altered fuel conditions coupled with changing climate have disrupted fire regimes of forests historically characterised by high-frequency and low-to-moderate-severity fire. Managers use fuel treatments to abate undesirable fire behaviour and effects. Short-term effectiveness of fuel treatments to alter fire behaviour and effects is well documented; however, long-term...

Electrochemical Characterisation of Bio-Bottle-Voltaic (BBV) Systems Operated with Algae and Built with Recycled Materials.

PubMed

Bateson, Peter; Fleet, Jack E H; Riseley, Anthony S; Janeva, Elena; Marcella, Anastasia S; Farinea, Chiara; Kuptsova, Maria; Conde Pueyo, Núria; Howe, Christopher J; Bombelli, Paolo; Parker, Brenda M

2018-04-17

Photobioelectrochemical systems are an emerging possibility for renewable energy. By exploiting photosynthesis, they transform the energy of light into electricity. This study evaluates a simple, scalable bioelectrochemical system built from recycled plastic bottles, equipped with an anode made from recycled aluminum, and operated with the green alga Chlorella sorokiniana . We tested whether such a system, referred to as a bio-bottle-voltaic (BBV) device, could operate outdoors for a prolonged time period of 35 days. Electrochemical characterisation was conducted by measuring the drop in potential between the anode and the cathode, and this value was used to calculate the rate of charge accumulation. The BBV systems were initially able to deliver ~500 mC·bottle −1 ·day −1 , which increased throughout the experimental run to a maximum of ~2000 mC·bottle −1 ·day −1 . The electrical output was consistently and significantly higher than that of the abiotic BBV system operated without algal cells (~100 mC·bottle −1 ·day −1 ). The analysis of the rate of algal biomass accumulation supported the hypothesis that harvesting a proportion of electrons from the algal cells does not significantly perturb the rate of algal growth. Our finding demonstrates that bioelectrochemical systems can be built using recycled components. Prototypes of these systems have been displayed in public events; they could serve as educational toolkits in schools and could also offer a solution for powering low-energy devices off-grid.

An attempt of modelling debris flows characterised by strong inertial effects through Cellular Automata

NASA Astrophysics Data System (ADS)

Iovine, G.; D'Ambrosio, D.

2003-04-01

Cellular Automata models do represent a valid method for the simulation of complex phenomena, when these latter can be described in "a-centric" terms - i.e. through local interactions within a discrete time-space. In particular, flow-type landslides (such as debris flows) can be viewed as a-centric dynamical system. SCIDDICA S4b, the last release of a family of two-dimensional hexagonal Cellular Automata models, has recently been developed for simulating debris flows characterised by strong inertial effects. It has been derived by progressively enriching an initial simplified CA model, originally derived for simulating very simple cases of slow-moving flow-type landslides. In S4b, by applying an empirical strategy, the inertial characters of the flowing mass have been translated into CA terms. In the transition function of the model, the distribution of landslide debris among the cells is computed by considering the momentum of the debris which move among the cells of the neighbourhood, and privileging the flow direction. By properly setting the value of one of the global parameters of the model (the "inertial factor"), the mechanism of distribution of the landslide debris among the cells can be influenced in order to emphasise the inertial effects, according to the energy of the flowing mass. Moreover, the high complexity of both the model and of the phenomena to be simulated (e.g. debris flows characterised by severe erosion along their path, and by strong inertial effects) suggested to employ an automated technique of evaluation, for the determination of the best set of global parameters. Accordingly, the calibration of the model has been performed through Genetic Algorithms, by considering several real cases of study: these latter have been selected among the population of landslides triggered in Campania (Southern Italy) in May 1998 and December 1999. Obtained results are satisfying: errors computed by comparing the simulations with the map of the real landslides are smaller than those previously obtained either through previous releases of the same model or without Genetic Algorithms. Nevertheless, results are still only preliminary, as the experiments have been realised in sequential computing environment. A more efficient calibration of the model would certainly be possible by adopting a parallel environment of computing, as a great number of tests could be performed in reasonable times; moreover, the parameters' optimisation could be realised in wider ranges, and in greater detail.

Characterisation of spectrophotometers used for spectral solar ultraviolet radiation measurements.

PubMed

Gröbner, J

2001-01-01

Spectrophotometers used for spectral measurements of the solar ultraviolet radiation need to be well characterised to provide accurate and reliable data. Since the characterisation and calibration are usually performed in the laboratory under conditions very different from those encountered during solar measurements, it is essential to address all issues concerned with the representativity of the laboratory characterisation with respect to the solar measurements. These include among others the instrument stability, the instrument linearity, the instrument responsivity, the wavelength accuracy, the spectral resolution, stray light rejection and the instrument dependence on ambient temperature fluctuations. These instrument parameters need to be determined often enough so that the instrument changes only marginally in the period between successive characterisations and therefore provides reliable data for the intervening period.

Manipulating and probing the polarisation of a methyl tunnelling system by field-cycling NMR

NASA Astrophysics Data System (ADS)

Zhang, Bo; Abu-Khumra, Sabah M. M.; Aibout, Abdellah; Horsewill, Anthony J.

2017-02-01

In NMR the polarisation of the Zeeman system may be routinely probed and manipulated by applying resonant rf pulses. As with spin-1/2 nuclei, at low temperature the quantum tunnelling states of a methyl rotor are characterised by two energy levels and it is interesting to consider how these tunnelling states might be probed and manipulated in an analogous way to nuclear spins in NMR. In this paper experimental procedures based on magnetic field-cycling NMR are described where, by irradiating methyl tunnelling sidebands, the polarisations of the methyl tunnelling systems are measured and manipulated in a prescribed fashion. At the heart of the technique is a phenomenon that is closely analogous to dynamic nuclear polarisation and the solid effect where forbidden transitions mediate polarisation transfer between 1H Zeeman and methyl tunnelling systems. Depending on the irradiated sideband, both positive and negative polarisations of the tunnelling system are achieved, the latter corresponding to population inversion and negative tunnelling temperatures. The transition mechanics are investigated through a series of experiments and a theoretical model is presented that provides good quantitative agreement.

Local structure of percolating gels at very low volume fractions

NASA Astrophysics Data System (ADS)

Griffiths, Samuel; Turci, Francesco; Royall, C. Patrick

2017-01-01

The formation of colloidal gels is strongly dependent on the volume fraction of the system and the strength of the interactions between the colloids. Here we explore very dilute solutions by the means of numerical simulations and show that, in the absence of hydrodynamic interactions and for sufficiently strong interactions, percolating colloidal gels can be realised at very low values of the volume fraction. Characterising the structure of the network of the arrested material we find that, when reducing the volume fraction, the gels are dominated by low-energy local structures, analogous to the isolated clusters of the interaction potential. Changing the strength of the interaction allows us to tune the compactness of the gel as characterised by the fractal dimension, with low interaction strength favouring more chain-like structures.

How much energy is locked in the USA? Alternative metrics for characterising the magnitude of overweight and obesity derived from BRFSS 2010 data.

PubMed

Reidpath, Daniel D; Masood, Mohd; Allotey, Pascale

2014-06-01

Four metrics to characterise population overweight are described. Behavioural Risk Factors Surveillance System data were used to estimate the weight the US population needed to lose to achieve a BMI < 25. The metrics for population level overweight were total weight, total volume, total energy, and energy value. About 144 million people in the US need to lose 2.4 million metric tonnes. The volume of fat is 2.6 billion litres-1,038 Olympic size swimming pools. The energy in the fat would power 90,000 households for a year and is worth around 162 million dollars. Four confronting ways of talking about a national overweight and obesity are described. The value of the metrics remains to be tested.

Gold deposit styles and placer gold characterisation in northern and east-central Madagascar

USGS Publications Warehouse

Pitfield, Peter E. J; Styles, Michael T.; Taylor, Cliff D.; Key, Roger M.; Bauer,; Ralison, A

2009-01-01

Microchemical characterisation of bedrock and placer gold grains from six gold districts within the Archaean domains and intervening Neoproterozoic Anaboriana-Manampotsy belt of northern and east-central Madagascar show few opaque inclusions (e.g pyrrhotite, Bi tellurides) but wide range of Ag contents (40wt%). Some districts exhibit multiple source populations of grains. The ‘greenstone belt’ terranes have an orogenic gold signature locally with an intrusion-related to epithermal overprint. Proterozoic metasediments with felsic to ultramafic bodies yield dominantly intrusion-related gold. A high proportion of secondary gold (<0.5wt% Ag) is related to recycling of paleoplacers and erosion of post-Gondwana planation surfaces and indicates that some mesothermal gold systems were already partially to wholly removed by erosion by the PermoTriassic.

A national EHR strategy preparedness characterisation model and its application in the South-East European region.

PubMed

Orfanidis, Leonidas; Bamidis, Panagiotis; Eaglestone, Barry

2006-01-01

This paper is concerned with modelling national approaches towards electronic health record systems (NEHRS) development. A model framework is stepwise produced, that allows for the characterisation of the preparedness and the readiness of a country to develop an NEHRS. Secondary data of published reports are considered for the creation of the model. Such sources are identified to mostly originate from within a sample of five developed countries. Factors arising from these sources are identified, coded and scaled, so as to allow for a quantitative application of the model. Instantiation of the latter for the case of the five developed countries is contrasted with the set of countries from South East Europe (SEE). The likely importance and validity of this modelling approach is discussed, using the Delphi method.

Understanding Super-Earths with MINERVA-Australis at USQ's Mount Kent Observatory

NASA Astrophysics Data System (ADS)

Wittenmyer, Robert; Horner, Jonathan; Kane, Stephen; Plavchan, Peter; Ciardi, David; Eastman, Jason; Johnson, John Asher; Wright, Jason; McCrady, Nate; MINERVA Collaboration

2018-01-01

Super Earths, planets between 5-10 Earth masses, are the most common types of planets known, yet are completely absent from our Solar system. As a result, their detailed properties, compositions, and formation mechanisms are poorly understood. NASA's Transiting Exoplanet Survey Satellite (TESS) will identify hundreds of Super-Earths orbiting bright stars, for the first time allowing in-depth characterisation of these planets. At the University of Southern Queensland, we are host to the MINERVA-Australis project, dedicated wholly to the follow-up characterisation and mass measurement of TESS planets. We give an update on the status of MINERVA-Australis and our expected performance. We also present results from the fully operational Northern MINERVA array, with the primary mission of discovering rocky planets orbiting 80 nearby bright stars.

Children's colour choices for completing drawings of affectively characterised topics.

PubMed

Burkitt, Esther; Barrett, Martyn; Davis, Alyson

2003-03-01

This study was designed to explore whether or not children systematically use particular colours when completing drawings of affectively characterised topics. Three hundred and thirty 4-11-year-old children were subdivided into three conditions, colouring in a drawing of a man, a dog, or a tree, respectively. The children completed two test sessions in counterbalanced order. In one session, children rated and ranked ten colours in order of preference. In the other session, children completed three colouring tasks in which they had to colour in three identical figures but which had been given different affective characterisations: a neutrally characterised figure, a figure characterised as nasty, and a figure characterised as nice. It was found that, in all age groups and for all topics, the children used their more preferred colours for the nice figures, their least preferred colours for the nasty figures, and colours rated intermediately for the neutral figures. It was also found that, in all age groups and for all topics, black tended to be the most frequently chosen colour for colouring in the drawings of the negatively characterised figures. By contrast, primary colours were predominantly selected for the neutral figure, while a wide range of mainly primary and secondary colours were chosen for colouring in the nice figure. These results suggest that children are able to alter systematically their use of colour during picture completion tasks in response to differential affective topic characterisations, and that even very young children are able to use colours symbolically.

A TOF-SIMS Investigation of the Volatile Inventory of Lithic and Mineral Clasts in Lunar Regolith Samples

NASA Astrophysics Data System (ADS)

Tartèse, R.; Lyon, I. C.

2017-07-01

The lunar regolith offers a key record to characterise the transfer of volatiles across the solar system for the past 4.5 billion years. We tackle this issue by investigating the volatile inventory of lunar regolith samples using TOF-SIMS.

Towards Community Oriented Curriculum in Finnish Literacy Education

ERIC Educational Resources Information Center

Makinen, Marita

2013-01-01

Finland's successful PISA "literacy results reflect" the foundation of the Finnish education system, which could be characterised by the words equality, equity and individual support. However, international interest in this PISA success has not focused on curricular aspects, and yet the core curriculum specifies teaching and learning practices in…

Professionalisation of Student Affairs Educators in China: History, Challenges, and Solutions

ERIC Educational Resources Information Center

Li, Youngshan; Fang, Yuanyuan

2017-01-01

Student affairs administration in Chinese universities is characterised by a dual-layer system of governance, with student affairs practitioners, i.e. advisors to students, being supervised by either central university administration or by affiliated colleges. In the last decade, government-oriented developments have achieved great success in…

FTIR-PAS: a powerful tool for characterising the chemical composition and predicting the labile C fraction of various organic waste products.

PubMed

Bekiaris, Georgios; Bruun, Sander; Peltre, Clément; Houot, Sabine; Jensen, Lars S

2015-05-01

Fourier transform infrared (FT-IR) spectroscopy has been used for several years as a fast, low-cost, reliable technique for characterising a large variety of materials. However, the strong influence of sample particle size and the inability to measure the absorption of very dark and opaque samples have made FTIR unsuitable for many waste materials. FTIR-photoacoustic spectroscopy (FTIR-PAS) can eliminate some of the shortcomings of traditional FTIR caused by scattering effects and reflection issues, and recent advances in PAS technology have made commercial instruments available. In this study, FTIR-PAS was used to characterise a wide range of organic waste products and predict their labile carbon fraction, which is normally determined from time-consuming assays. FTIR-PAS was found to be capable of predicting the labile fraction of carbon as efficiently as near infrared spectroscopy (NIR) and furthermore of identifying the compounds that are correlated with the predicted parameter, thus facilitating a more mechanistic interpretation. Copyright © 2015 Elsevier Ltd. All rights reserved.

A mechanical characterisation on multiple timescales of electroconductive magnetorheological elastomers

NASA Astrophysics Data System (ADS)

Schümann, M.; Morich, J.; Kaufhold, T.; Böhm, V.; Zimmermann, K.; Odenbach, S.

2018-05-01

Magnetorheological elastomers are a type of smart hybrid material which combines elastic properties of a soft elastomer matrix with magnetic properties of magnetic micro particles. This leads to a material with magnetically controllable mechanical properties of which the magnetorheological effect is the best known. The addition of electroconductive particles to the polymer mix adds electrical properties to the material behaviour. The resulting electrical resistance of the sample can be manipulated by external magnetic fields and mechanical loads. This results in a distinct interplay of mechanical, electrical and magnetic effects with a highly complex time behaviour. In this paper a mechanical characterisation on multiple time scales was conducted to get an insight on the short and long-term electrical and mechanical behaviour of this novel material. The results show a complex resistivity behaviour on several timescales, sensitive to magnetic fields and strain velocity. The observed material exhibits fatigue and relaxation behaviour, whereas the magnetorheological effect appears not to interfere with the piezoresistive properties.

Metabolomic profiling of beer reveals effect of temperature on non-volatile small molecules during short-term storage.

PubMed

Heuberger, Adam L; Broeckling, Corey D; Lewis, Matthew R; Salazar, Lauren; Bouckaert, Peter; Prenni, Jessica E

2012-12-01

The effect of temperature on non-volatile compounds in beer has not been well characterised during storage. Here, a metabolomics approach was applied to characterise the effect of storage temperature on non-volatile metabolite variation after 16weeks of storage, using fresh beer as a control. The metabolite profile of room temperature stored (RT) and cold temperature stored (CT) beer differed significantly from fresh, with the most substantial variation observed between RT and fresh beer. Metabolites that changed during storage included prenylated flavonoids, purines, and peptides, and all showed reduced quantitative variation under the CT storage conditions. Corresponding sensory panel observations indicated significant beer oxidation after 12 and 16weeks of storage, with higher values reported for RT samples. These data support that temperature affected beer oxidation during short-term storage, and reveal 5-methylthioadenosine (5-MTA) as a candidate non-volatile metabolite marker for beer oxidation and staling. Copyright © 2012 Elsevier Ltd. All rights reserved.

Beyond medical pluralism: characterising health-care delivery of biomedicine and traditional medicine in rural Guatemala.

PubMed

Hoyler, Elizabeth; Martinez, Roxana; Mehta, Kurren; Nisonoff, Hunter; Boyd, David

2018-04-01

Although approximately one half of Guatemalans are indigenous, the Guatemalan Maya account for 72% of the extremely poor within the country. While some biomedical services are available in these communities, many Maya utilise traditional medicine as a significant, if not primary, source of health care. While existing medical anthropological research characterises these modes of medicine as medically dichotomous or pluralistic, our research in a Maya community of the Western Highlands, Concepción Huista, builds on previous studies and finds instead a syncretistic, imbricated local health system. We find significant overlap and interpenetration of the biomedical and traditional medical models that are described best as a framework where practitioners in both settings employ elements of the other in order to best meet community needs. By focusing on the practitioner's perspective, we demonstrate that in addition to patients' willingness to seek care across health systems, practitioners converse across seemingly distinct systems via incorporation of certain elements of the 'other'. Interventions to date have not accounted for this imbrication. Guatemalan governmental policies to support local healers have led to little practical change in the health-care landscape of the country. Therefore, understanding this complex imbrication is crucial for interventions and policy changes.

Performance-based financing in low-income and middle-income countries: isn’t it time for a rethink?

PubMed Central

Albert, Lucien; Bisala, Badibanga N’Sambuka; Bodson, Oriane; Bonnet, Emmanuel; Bossyns, Paul; Colombo, Sandro; De Brouwere, Vincent; Dumont, Alexandre; Eclou, Dieudonné Sèdjro; Gyselinck, Karel; Hane, Fatoumata; Marchal, Bruno; Meloni, Remo; Noirhomme, Mathieu; Noterman, Jean-Pierre; Samb, Oumar Mallé; Ssengooba, Freddie; Touré, Laurence; Turcotte-Tremblay, Anne-Marie; Van Belle, Sara; Vinard, Philippe

2018-01-01

This paper questions the view that performance-based financing (PBF) in the health sector is an effective, efficient and equitable approach to improving the performance of health systems in low-income and middle-income countries (LMICs). PBF was conceived as an open approach adapted to specific country needs, having the potential to foster system-wide reforms. However, as with many strategies and tools, there is a gap between what was planned and what is actually implemented. This paper argues that PBF as it is currently implemented in many contexts does not satisfy the promises. First, since the start of PBF implementation in LMICs, concerns have been raised on the basis of empirical evidence from different settings and disciplines that indicated the risks, cost and perverse effects. However, PBF implementation was rushed despite insufficient evidence of its effectiveness. Second, there is a lack of domestic ownership of PBF. Considering the amounts of time and money it now absorbs, and the lack of evidence of effectiveness and efficiency, PBF can be characterised as a donor fad. Third, by presenting itself as a comprehensive approach that makes it possible to address all aspects of the health system in any context, PBF monopolises attention and focuses policy dialogue on the short-term results of PBF programmes while diverting attention and resources from broader processes of change and necessary reforms. Too little care is given to system-wide and long-term effects, so that PBF can actually damage health services and systems. This paper ends by proposing entry points for alternative approaches. PMID:29564163

The GAPS programme with HARPS-N at TNG. XVI. Measurement of the Rossiter-McLaughlin effect of transiting planetary systems HAT-P-3, HAT-P-12, HAT-P-22, WASP-39, and WASP-60

NASA Astrophysics Data System (ADS)

Mancini, L.; Esposito, M.; Covino, E.; Southworth, J.; Biazzo, K.; Bruni, I.; Ciceri, S.; Evans, D.; Lanza, A. F.; Poretti, E.; Sarkis, P.; Smith, A. M. S.; Brogi, M.; Affer, L.; Benatti, S.; Bignamini, A.; Boccato, C.; Bonomo, A. S.; Borsa, F.; Carleo, I.; Claudi, R.; Cosentino, R.; Damasso, M.; Desidera, S.; Giacobbe, P.; González-Álvarez, E.; Gratton, R.; Harutyunyan, A.; Leto, G.; Maggio, A.; Malavolta, L.; Maldonado, J.; Martinez-Fiorenzano, A.; Masiero, S.; Micela, G.; Molinari, E.; Nascimbeni, V.; Pagano, I.; Pedani, M.; Piotto, G.; Rainer, M.; Scandariato, G.; Smareglia, R.; Sozzetti, A.; Andreuzzi, G.; Henning, Th.

2018-05-01

Context. The measurement of the orbital obliquity of hot Jupiters with different physical characteristics can provide clues to the mechanisms of migration and orbital evolution of this particular class of giant exoplanets. Aims: We aim to derive the degree of alignment between planetary orbit and stellar spin angular momentum vectors and look for possible links with other orbital and fundamental physical parameters of the star-planet system. We focus on the characterisation of five transiting planetary systems (HAT-P-3, HAT-P-12, HAT-P-22, WASP-39, and WASP-60) and the determination of their sky-projected planet orbital obliquity through the measurement of the Rossiter-McLaughlin effect. Methods: We used HARPS-N high-precision radial velocity measurements, gathered during transit events, to measure the Rossiter-McLaughlin effect in the target systems and determine the sky-projected angle between the planetary orbital plane and stellar equator. The characterisation of stellar atmospheric parameters was performed by exploiting the HARPS-N spectra, using line equivalent width ratios and spectral synthesis methods. Photometric parameters of the five transiting exoplanets were re-analysed through 17 new light curves, obtained with an array of medium-class telescopes, and other light curves from the literature. Survey-time-series photometric data were analysed for determining the rotation periods of the five stars and their spin inclination. Results: From the analysis of the Rossiter-McLaughlin effect we derived a sky-projected obliquity of λ = 21.2° ± 8.7°, λ = -54°-13°+41°, λ = -2.1° ± 3.0°, λ = 0° ± 11°, and λ = -129° ± 17° for HAT-P-3 b, HAT-P-12 b, HAT-P-22 b, WASP-39 b, and WASP-60 b, respectively. The latter value indicates that WASP-60 b is moving on a retrograde orbit. These values represent the first measurements of λ for the five exoplanetary systems under study. The stellar activity of HAT-P-22 indicates a rotation period of 28.7 ± 0.4 days, which allowed us to estimate the true misalignment angle of HAT-P-22 b, ψ = 24° ± 18°. The revision of the physical parameters of the five exoplanetary systems returned values that are fully compatible with those existing in the literature. The exception to this is the WASP-60 system, for which, based on higher quality spectroscopic and photometric data, we found a more massive and younger star and a larger and hotter planet. Tables of the light curve and radial velocity data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/613/A41

Identification and Characterisation of Wetlands For A Correct Basin Management

NASA Astrophysics Data System (ADS)

Quadrado, F.; Gomes, F.

The effects of human activities on water resources have great conse- quences for water users. Some of the problems affecting water resources arise from conflicting uses, including discharge of untreated industrial and domestic wastewater and inadequate agricultural practices on the watersheds. The knowledge of hydrologic and water quality characteristics and behaviour of the system will provide the basis for action to prevent the degradation of water resources. So comprehensive and ratio- nal water management is a necessary condition for social and economic development. The Water Framework Directive defines a good status for all waters all types of waters to be achieved in 15 years. To wetlands the Directive purpose the prevention of their degradation and the protection of those wetlands directly depending on aquatic sys- tems. The sensitiveness of wetlands leads to a difficult management of this resources where it is necessary to know the dynamic of the system and the pressures that can change the ecosystem equilibrium. In spite of the critical role of wetlands, there is a lack of information related with these areas, many times not included in the monitor- ing activity routines. A water quality-monitoring network is an essential instrument of water management. Portugal is now redesigning their freshwater network monitoring in a watershed basis, to provide the necessary data to preserve and control the water quality of the rivers and reservoirs. The combined approach principle to the protec- tion of water that is defended in the Water Framework Directive, was adopted. One of the criterion used to the localisation of sampling stations were characterisation of protected areas. Portugal due to his natural and climate conditions have some impor- tant and unique ecosystems, sometimes being considered as protected areas. Their characteristics must be studied and their equilibrium preserved. Anyhow a little at- tention had been provided to these zones and the actual monitoring network does not take in account the specialities of these areas. Portugal presently has 12 sites desig- nated as Wetlands of International Importance, with a surface area of 66,096 hectares. This work pretend to identify and characterised the wetland areas in Portugal, evaluate their degradation and the requirements of the Water Framework Directive with regard to wetlands. Also the importance of this systems to the watershed management is dis- cussed and the improvements with the implementation of the new monitoring network on controlling and preserving water quality in wetlands areas.

Community, intervention and provider support influences on implementation: reflections from a South African illustration of safety, peace and health promotion.

PubMed

van Niekerk, Ashley; Seedat, Mohamed; Kramer, Sherianne; Suffla, Shahnaaz; Bulbulia, Samed; Ismail, Ghouwa

2014-01-01

The development, implementation and evaluation of community interventions are important for reducing child violence and injuries in low- to middle-income contexts, with successful implementation critical to effective intervention outcomes. The assessment of implementation processes is required to identify the factors that influence effective implementation. This article draws on a child safety, peace and health initiative to examine key factors that enabled or hindered its implementation, in a context characterised by limited resources. A case study approach was employed. The research team was made up of six researchers and intervention coordinators, who led the development and implementation of the Ukuphepha Child Study in South Africa, and who are also the authors of this article. The study used author observations, reflections and discussions of the factors perceived to influence the implementation of the intervention. The authors engaged in an in-depth and iterative dialogic process aimed at abstracting the experiences of the intervention, with a recursive cycle of reflection and dialogue. Data were analysed utilising inductive content analysis, and categorised using classification frameworks for understanding implementation. The study highlights key factors that enabled or hindered implementation. These included the community context and concomitant community engagement processes; intervention compatibility and adaptability issues; community service provider perceptions of intervention relevance and expectations; and the intervention support system, characterised by training and mentorship support. This evaluation illustrated the complexity of intervention implementation. The study approach sought to support intervention fidelity by fostering and maintaining community endorsement and support, a prerequisite for the unfolding implementation of the intervention.

Dendrimer pre-treatment enhances the skin permeation of chlorhexidine digluconate: Characterisation by in vitro percutaneous absorption studies and Time-of-Flight Secondary Ion Mass Spectrometry.

PubMed

Holmes, Amy M; Scurr, David J; Heylings, Jon R; Wan, Ka-Wai; Moss, Gary P

2017-06-15

Skin penetration and localisation of chlorhexidine digluconate (CHG) within the skin have been investigated in order to better understand and optimise the delivery using a nano polymeric delivery system of this topically-applied antimicrobial drug. Franz-type diffusion cell studies using in vitro porcine skin and tape stripping procedures were coupled with Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) to visualise the skin during various treatments with CHG and polyamidoamine dendrimers (PAMAM). Pre-treatment of the skin with PAMAM dendrimers significantly increased the amount and depth of permeation of CHG into the skin in vitro. The effect observed was not concentration dependant in the range 0.5-10mM PAMAM. This could be important in terms of the efficiency of treatment of bacterial infection in the skin. It appears that the mechanism of enhancement is due to the PAMAM dendrimer disrupting skin barrier lipid conformation or by occluding the skin surface. Franz-type diffusion cell experiments are complimented by the detailed visualisation offered by the semi-quantitative ToF-SIMS method which provides excellent benefits in terms of sensitivity and fragment ion specificity. This allows a more accurate depth profile of chlorhexidine permeation within the skin to be obtained and potentially affords the opportunity to map the co-localisation of permeants with skin structures, thus providing a greater ability to characterise skin absorption and to understand the mechanism of permeation, providing opportunities for new and more effective therapies. Copyright © 2017. Published by Elsevier B.V.

Community, intervention and provider support influences on implementation: reflections from a South African illustration of safety, peace and health promotion

PubMed Central

2014-01-01

Background The development, implementation and evaluation of community interventions are important for reducing child violence and injuries in low- to middle-income contexts, with successful implementation critical to effective intervention outcomes. The assessment of implementation processes is required to identify the factors that influence effective implementation. This article draws on a child safety, peace and health initiative to examine key factors that enabled or hindered its implementation, in a context characterised by limited resources. Methods A case study approach was employed. The research team was made up of six researchers and intervention coordinators, who led the development and implementation of the Ukuphepha Child Study in South Africa, and who are also the authors of this article. The study used author observations, reflections and discussions of the factors perceived to influence the implementation of the intervention. The authors engaged in an in-depth and iterative dialogic process aimed at abstracting the experiences of the intervention, with a recursive cycle of reflection and dialogue. Data were analysed utilising inductive content analysis, and categorised using classification frameworks for understanding implementation. Results The study highlights key factors that enabled or hindered implementation. These included the community context and concomitant community engagement processes; intervention compatibility and adaptability issues; community service provider perceptions of intervention relevance and expectations; and the intervention support system, characterised by training and mentorship support. Conclusions This evaluation illustrated the complexity of intervention implementation. The study approach sought to support intervention fidelity by fostering and maintaining community endorsement and support, a prerequisite for the unfolding implementation of the intervention. PMID:25081088

Biosynthesis of silver and platinum nanoparticles using orange peel extract: characterisation and applications.

PubMed

Castro, Laura; Blázquez, María Luisa; González, Felisa; Muñoz, Jesús Ángel; Ballester, Antonio

2015-10-01

This study focuses on the green synthesis of noble metal nanoparticles (silver (Ag) and platinum (Pt)) and how the size and shape of the nanoparticles produced can be controlled through changes in the initial pH value of the precursor solution. The nanoparticles were characterised by ultra-violet-visible spectroscopy, transmission electron microscopy and X-ray diffraction. This simple and environmentally friendly method allows the synthesis of diverse nanostructures in the absence of a surfactant or polymer to direct nanoparticle growth, and without externally adding seed crystallites. The antibacterial effects of Ag nanoparticles and catalytic properties of Pt nanoparticles were explored for future promising biotechnological approaches in different fields.

The relevance of the amorphous state to pharmaceutical dosage forms: glassy drugs and freeze dried systems.

PubMed

Craig, D Q; Royall, P G; Kett, V L; Hopton, M L

1999-03-15

Many pharmaceuticals, either by accident or design, may exist in a total or partially amorphous state. Consequently, it is essential to have an understanding of the physico-chemical principles underpinning the behaviour of such systems. In this discussion, the nature of the glassy state will be described, with particular emphasis on the molecular processes associated with glass transitional behaviour and the use of thermal methods for characterising the glass transition temperature, Tg. The practicalities of such measurements, the significance of the accompanying relaxation endotherm and plasticization effects are considered. The advantages and difficulties associated with the use of amorphous drugs will be outlined, with discussion given regarding the problems associated with physical and chemical stability. Finally, the principles of freeze drying will be described, including discussion of the relevance of glass transitional behaviour to product stability. Copyright

Measurement of anal pressure and motility.

PubMed Central

Hancock, B D

1976-01-01

A fine open perfused system and a closed balloon system for the measurement of anal pressure and motility have been compared. Measurements were made in 40 normal subjects and 84 patients with haemorrhoids. The rate of perfusion had a marked effect on the recorded pressure and motility details. The motility pattern was seen most clearly with the balloon probe and the pressure recorded was reproducible and easy to measure, making this a convenient method for recording activity of the internal anal sphincter. Anal motility in normal subjects was characterised by slow pressure waves (10-20/min). The frequency was fastest in the distal anal canal and this frequency gradient may represent a normal mechanism to keep the anal canal empty. Ultra slow pressure waves (0-6-1-9/min) were seen in 42% of patients with haemorrhoids and 5% of normal subjects and arose from a synchronous contraction of the whole internal sphincter. Images Fig. 1 PMID:976803

Characterisation of a cryostat using simultaneous, single-beam multiple-surface laser vibrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kissinger, Thomas; Charrett, Thomas O. H.; James, Stephen W.

2016-06-28

A novel range-resolved interferometric signal processing technique that uses sinusoidal optical frequency modulation is applied to multi-surface vibrometry, demonstrating simultaneous optical measurements of vibrations on two surfaces using a single, collimated laser beam, with a minimum permissible distance of 3.5 cm between surfaces. The current system, using a cost-effective laser diode and a fibre-coupled, downlead insensitive setup, allows an interferometric fringe rate of up to 180 kHz to be resolved with typical displacement noise levels of 8 pm · Hz{sup −05}. In this paper, the system is applied to vibrometry measurements of a table-top cryostat, with concurrent measurements of the optical widowmore » and the sample holder target inside. This allows the separation of common-mode vibrations of the whole cryostat from differential vibrations between the window and the target, allowing any resonances to be identified.« less

Artificial neural networks for the performance prediction of heat pump hot water heaters

NASA Astrophysics Data System (ADS)

Mathioulakis, E.; Panaras, G.; Belessiotis, V.

2018-02-01

The rapid progression in the use of heat pumps, due to the decrease in the equipment cost, together with the favourable economics of the consumed electrical energy, has been combined with the wide dissemination of air-to-water heat pumps (AWHPs) in the residential sector. The entrance of the respective systems in the commercial sector has made important the modelling of the processes. In this work, the suitability of artificial neural networks (ANN) in the modelling of AWHPs is investigated. The ambient air temperature in the evaporator inlet and the water temperature in the condenser inlet have been selected as the input variables; energy performance indices and quantities characterising the operation of the system have been selected as output variables. The results verify that the, easy-to-implement, trained ANN can represent an effective tool for the prediction of the AWHP performance in various operation conditions and the parametrical investigation of their behaviour.

Stability, performance and sensitivity analysis of I.I.D. jump linear systems

NASA Astrophysics Data System (ADS)

Chávez Fuentes, Jorge R.; González, Oscar R.; Gray, W. Steven

2018-06-01

This paper presents a symmetric Kronecker product analysis of independent and identically distributed jump linear systems to develop new, lower dimensional equations for the stability and performance analysis of this type of systems than what is currently available. In addition, new closed form expressions characterising multi-parameter relative sensitivity functions for performance metrics are introduced. The analysis technique is illustrated with a distributed fault-tolerant flight control example where the communication links are allowed to fail randomly.

The surgical management of severe macroglossia in systemic AL amyloidosis.

PubMed

Cobb, Alistair R M; Boyapati, Raghu; Walker, Donald Murray; Dunaway, David J; Lloyd, Timothy W

2013-07-01

Amyloidosis is a disease characterised by the deposition in body tissues of amyloid: abnormal protein in a beta pleated sheet formation. It is a systemic disorder and macroglossia may be seen in all forms. Changes to the normal architecture of the tissues and systemic features of the disease and its underlying cause can complicate the surgical management of the enlarged tongue. Copyright © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The concept of hierarchy in general systems theory.

PubMed

Gasparski, W

1994-01-01

The paper reviews main ideas related to the concept of hierarchy as they are discussed in contemporary general systems theory. After presenting a dictionary definition of the concept, the author examines the intuitive idea of hierarchy quoting Mario Bunge's notion of level structure. Then relationship between two other concepts: a system and a hierarchy is characterised on the bases of Bowler's, Bunge's again, Klir's, and the author's studies. Finally, the paper is concluded that hierarchy is not an otological concept but epistemological one.

Assessing a traceability technique in fresh oranges (Citrus sinensis L. Osbeck) with an HS-SPME-GC-MS method. Towards a volatile characterisation of organic oranges.

PubMed

Cuevas, Francisco Julián; Moreno-Rojas, José Manuel; Ruiz-Moreno, María José

2017-04-15

A targeted approach using HS-SPME-GC-MS was performed to compare flavour compounds of 'Navelina' and 'Salustiana' orange cultivars from organic and conventional management systems. Both varieties of conventional oranges showed higher content of ester compounds. On the other hand, higher content of some compounds related with the geranyl-diphosphate pathway (neryl and geranyl acetates) and some terpenoids were found in the organic samples. Furthermore, the partial least square discriminant analysis (PLS-DA) achieved an effective classification for oranges based on the farming system using their volatile profiles (90 and 100% correct classification). To our knowledge, it is the first time that a comparative study dealing with farming systems and orange aroma profile has been performed. These new insights, taking into account local databases, cultivars and advanced analytical tools, highlight the potential of volatile composition for organic orange discrimination. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reduced Height (Rht) Alleles Affect Wheat Grain Quality

PubMed Central

Casebow, Richard; Hadley, Caroline; Uppal, Rajneet; Addisu, Molla; Loddo, Stefano; Kowalski, Ania; Griffiths, Simon; Gooding, Mike

2016-01-01

The effects of dwarfing alleles (reduced height, Rht) in near isogenic lines on wheat grain quality are characterised in field experiments and related to effects on crop height, grain yield and GA-sensitivity. Alleles included those that conferred GA-insensitivity (Rht-B1b, Rht-B1c, Rht-D1b, Rht-D1c) as well as those that retained GA-sensitivity (rht(tall), Rht8, Rht8 + Ppd-D1a, Rht12). Full characterisation was facilitated by including factors with which the effects of Rht alleles are known to interact for grain yield (i.e. system, [conventional or organic]; tillage intensity [plough-based, minimum or zero]; nitrogen fertilizer level [0–450 kg N/ha]; and genetic backgrounds varying in height [cvs Maris Huntsman, Maris Widgeon, and Mercia]. Allele effects on mean grain weight and grain specific weight were positively associated with final crop height: dwarfing reduced these quality criteria irrespective of crop management or GA-sensitivity. In all but two experiments the effects of dwarfing alleles on grain nitrogen and sulphur concentrations were closely and negatively related to effects on grain yield, e.g. a quadratic relationship between grain yield and crop height manipulated by the GA-insensitive alleles was mirrored by quadratic relationships for nitrogen and sulphur concentrations: the highest yields and most dilute concentrations occurred around 80cm. In one of the two exceptional experiments the GA-insensitive Rht-B1b and Rht-B1c significantly (P<0.05) reduced grain nitrogen concentration in the absence of an effect on yield, and in the remaining experiment the GA-sensitive Rht8 significantly reduced both grain yield and grain nitrogen concentration simultaneously. When Rht alleles diluted grain nitrogen concentration, N:S ratios and SDS-sedimentation volumes were often improved. Hagberg falling number (HFN) was negatively related to crop height but benefits from dwarfing were only seen for GA-insensitive alleles. For HFN, therefore, there was the strongest evidence for a direct pleiotropic effect of GA-insensitivity, rather than an effect consequential to yield and/or height. PMID:27196288

Reduced Height (Rht) Alleles Affect Wheat Grain Quality.

PubMed

Casebow, Richard; Hadley, Caroline; Uppal, Rajneet; Addisu, Molla; Loddo, Stefano; Kowalski, Ania; Griffiths, Simon; Gooding, Mike

2016-01-01

The effects of dwarfing alleles (reduced height, Rht) in near isogenic lines on wheat grain quality are characterised in field experiments and related to effects on crop height, grain yield and GA-sensitivity. Alleles included those that conferred GA-insensitivity (Rht-B1b, Rht-B1c, Rht-D1b, Rht-D1c) as well as those that retained GA-sensitivity (rht(tall), Rht8, Rht8 + Ppd-D1a, Rht12). Full characterisation was facilitated by including factors with which the effects of Rht alleles are known to interact for grain yield (i.e. system, [conventional or organic]; tillage intensity [plough-based, minimum or zero]; nitrogen fertilizer level [0-450 kg N/ha]; and genetic backgrounds varying in height [cvs Maris Huntsman, Maris Widgeon, and Mercia]. Allele effects on mean grain weight and grain specific weight were positively associated with final crop height: dwarfing reduced these quality criteria irrespective of crop management or GA-sensitivity. In all but two experiments the effects of dwarfing alleles on grain nitrogen and sulphur concentrations were closely and negatively related to effects on grain yield, e.g. a quadratic relationship between grain yield and crop height manipulated by the GA-insensitive alleles was mirrored by quadratic relationships for nitrogen and sulphur concentrations: the highest yields and most dilute concentrations occurred around 80cm. In one of the two exceptional experiments the GA-insensitive Rht-B1b and Rht-B1c significantly (P<0.05) reduced grain nitrogen concentration in the absence of an effect on yield, and in the remaining experiment the GA-sensitive Rht8 significantly reduced both grain yield and grain nitrogen concentration simultaneously. When Rht alleles diluted grain nitrogen concentration, N:S ratios and SDS-sedimentation volumes were often improved. Hagberg falling number (HFN) was negatively related to crop height but benefits from dwarfing were only seen for GA-insensitive alleles. For HFN, therefore, there was the strongest evidence for a direct pleiotropic effect of GA-insensitivity, rather than an effect consequential to yield and/or height.

Synthesis, X-ray characterisation and reactions of a trigonal planar palladium(0) carbonyl complex, (tbpx)PdCO.

PubMed

Bellabarba, Ronan M; Tooze, Robert P; Slawin, Alexandra M Z

2003-08-07

The novel complex (tbpx)PdCO (1), the first example of a structurally characterised sixteen electron, trigonal planar palladium(0) carbonyl complex, was prepared, characterised by NMR spectroscopy and X-ray crystallography, and some unusual aspects of its reactivity were studied.

Effects of thermal treatments on the characterisation and utilisation of red mud with sawdust additive.

PubMed

Liu, Yanju; Naidu, Ravi; Ming, Hui; Dharmarajan, Rajarathnam; Du, Jianhua

2016-06-01

Extremely large amounts of red mud (bauxite residue) are generated globally every year from alumina refining industries, which are being disposed of on engineered landfills. The objective of this study is to investigate the effects of thermal treatments on red mud for development of utilisation strategies. Thermal treatments of red mud samples and their characterisations were investigated under inert (N2) and oxidative (air) conditions with and without sawdust addition at 200-600°C. After calcination, the resulting samples were analysed using thermogravimetric-infrared spectroscopy (TG-IR) for functional group transformations, thermogravimetric analysis (TGA) for thermal loss profiles and X-ray diffraction (XRD) for mineral transformations. The characterisation results showed that in N2 environment, boehmite in red mud was transferred to transition alumina at around 400°C while losing water from structural components. The addition of sawdust for incubation and calcination of red mud in air increased the surface area, whereas that in nitrogen atmosphere lead to reduction of hematite to magnetite at around 500°C. The incorporated carbon materials played a major role in increasing the surface area especially for pore size less than 2.5 nm. This treated red mud with altered mineral composition and improved properties for binding contaminants can be used for environmental remediation and in the process of metal recovery such as iron. © The Author(s) 2016.

Characterising the transport and preservation of microbial tetraether membrane lipids in Karst Systems

NASA Astrophysics Data System (ADS)

Jex, C.; Blyth, A. J.; Baker, A.; Mcdonald, J. A.; Woltering, M.; Khan, S. J.

2013-12-01

Stalagmites have the potential to preserve organic biomarkers, proxies for changes in surface climate. Of particular interest is a class of microbial-derived lipids, the glycerol dialkyl glycerol tetraetheral (GDGT) lipids, which have been identified in cave deposits (Yang et al. 2011). Speleothem GDGT composition has been demonstrated to correlate with surface air temperature using the achaea derived isoprenoid ';(i)GDGT' index of TEX86 and the bacteria derived branched ';(b)GDGT' index of MBT/CBT of modern speleothem samples (Blyth & Schouten, 2013), indicating considerable potential for paleo-temperature reconstructions. These studies have suggested two competing sources for GDGTs in karst systems: 1) A soil derived microbial signal dominated by bGDGTs and 2) An in situ signal dominated by iGDGTs, representative of achaea existing within the cave or overlying bedrock, which dominates the speleothem signal. These findings are yet to be thoroughly tested by characterising the seasonal and spatial nature of GDGTs within caves to establish their sources and transport pathways within these complex fractured rock systems. We address this by presenting the preliminary results of a monitoring study of GDGTs within a single cave system, in South East Australia. Harrie Wood cave in Kosciusko national park is a high altitude, semi-arid site, dominated by discrete infiltration events throughout the year. Above the cave there are thin soils consisting of loose shallow scree, steep slopes and sparse shrub vegetation. We present data obtained from waters and soils immediately above and within Harrie Wood as well as in situ collection of GDGTs formed on filter papers left inside the cave throughout the year. A second cave within the same system provides contrasting surface conditions: thick red clays of moderate to no slope and Eucalypt dominated forest. As such these caves provide ideal test sites to characterise the variability in GDGT signals that may be a result of non-temperature related factors, including varying inputs (groundwater vs. in situ growth) or site specific hydrological conditions. Blyth, A.J., Schouten, S., 2013. Geochimica et Cosmochimica Acta 109, 312-328. Yang, H. et al. 2011. Organic Geochemistry 42, 108-115.

Comments on pesticide risk assessment by the revision of Directive EU 91/414.

PubMed

Balderacchi, Matteo; Trevisan, Marco

2010-03-01

Human health and the environment are major concerns for European Commission policy on the authorisation of plant protection products. The new regulation that revises and replaces the directive 91/414/EC moves towards the adoption of a Persistent Bioaccumulation Toxicity cutoff criterion because current pesticide risk assessment (PRA) is deterministic, based on few standard cases and therefore characterised by uncertainty. This revision could create concerns about sustainability. This paper analyses some effects of this directive on the agrochemical market and assumes new effects resulting from the introduction of the revision. Suggestions are made as to how pesticide risk assessment will have to adapt to answer the request of legislators on safety standards and sustainability, introducing probabilistic PRA. Toxicity and exposure functions will be fully characterised, producing distributions of predicted impact and quantifying the variability and uncertainty. For adopting PRA studies at the local/catchment scale, new assessment schemes will be necessary.

Unveiling the pan-genome of the SXT/R391 family of ICEs: molecular characterisation of new variable regions of SXT/R391-like ICEs detected in Pseudoalteromonas sp. and Vibrio scophthalmi.

PubMed

Rodríguez-Blanco, Arturo; Lemos, Manuel L; Osorio, Carlos R

2016-08-01

Integrating conjugative elements (ICEs) of the SXT/R391 family have been identified in fish-isolated bacterial strains collected from marine aquaculture environments of the northwestern Iberian Peninsula. Here we analysed the variable regions of two ICEs, one preliminarily characterised in a previous study (ICEVscSpa3) and one newly identified (ICEPspSpa1). Bacterial strains harboring these ICEs were phylogenetically assigned to Vibrio scophthalmi and Pseudoalteromonas sp., thus constituting the first evidence of SXT/R391-like ICEs in the genus Pseudoalteromonas to date. Variable DNA regions, which confer element-specific properties to ICEs of this family, were characterised. Interestingly, the two ICEs contained 29 genes not found in variable DNA insertions of previously described ICEs. Most notably, variable gene content for ICEVscSpa3 showed similarity to genes potentially involved in housekeeping functions of replication, nucleotide metabolism and transcription. For these genes, closest homologues were found clustered in the genome of Pseudomonas psychrotolerans L19, suggesting a transfer as a block to ICEVscSpa3. Genes encoding antibiotic resistance, restriction modification systems and toxin/antitoxin systems were absent from hotspots of ICEVscSpa3. In contrast, the variable gene content of ICEPspSpa1 included genes involved in restriction/modification functions in two different hotspots and genes related to ICE maintenance. The present study unveils a relatively large number of novel genes in SXT/R391-ICEs, and demonstrates the major role of ICE elements as contributors to horizontal gene transfer.

Stability of a Cosmetic Multiple Emulsion Loaded with Green Tea Extract

PubMed Central

Mahmood, Tariq; Akhtar, Naveed

2013-01-01

Multiple emulsions are excellent and exciting potential systems for the delivery of useful cosmetic agents. The work describes stability of a multiple emulsion for cosmetic purpose, loaded with extract of Camellia sinensis L. (Theaceae) in concentration of 5%. The formulation constitutes of cetyl dimethicone copolyol and polyoxyethylene (20) cetyl ether as emulsifiers and was characterised and monitored for various physicochemical aspects. Centrifugation has no devastating effect on physical destabilization/phase separation observed for 30 days. Mean globule sizes of multiple droplets were found in the range of 10.29 ± 4.4 μm to 12.77 ± 5.1 μm and of inner droplets were in the range of 0.8 ± 0.4 μm to 1.6 ± 0.8 μm. All samples exhibited shear thinning behavior with increase in shear stress. The results of the present study indicate that multiple emulsions can be used as carrier of 5% Camellia sinensis L. extract to enhance desired effects. The developed physically and chemically stable system is an effective system for targeting skin layers; however, long-term stability at elevated temperatures may be needed with suitable modifications, if required. PMID:24058284

Characterisation of serpin polymers in vitro and in vivo.

PubMed

Belorgey, Didier; Irving, James A; Ekeowa, Ugo I; Freeke, Joanna; Roussel, Benoit D; Miranda, Elena; Pérez, Juan; Robinson, Carol V; Marciniak, Stefan J; Crowther, Damian C; Michel, Claire H; Lomas, David A

2011-03-01

Neuroserpin is a member of the serine protease inhibitor or serpin superfamily of proteins. It is secreted by neurones and plays an important role in the regulation of tissue plasminogen activator at the synapse. Point mutations in the neuroserpin gene cause the autosomal dominant dementia familial encephalopathy with neuroserpin inclusion bodies or FENIB. This is one of a group of disorders caused by mutations in the serpins that are collectively known as the serpinopathies. Others include α(1)-antitrypsin deficiency and deficiency of C1 inhibitor, antithrombin and α(1)-antichymotrypsin. The serpinopathies are characterised by delays in protein folding and the retention of ordered polymers of the mutant serpin within the cell of synthesis. The clinical phenotype results from either a toxic gain of function from the inclusions or a loss of function, as there is insufficient protease inhibitor to regulate important proteolytic cascades. We describe here the methods required to characterise the polymerisation of neuroserpin and draw parallels with the polymerisation of α(1)-antitrypsin. It is important to recognise that the conditions in which experiments are performed will have a major effect on the findings. For example, incubation of monomeric serpins with guanidine or urea will produce polymers that are not found in vivo. The characterisation of the pathological polymers requires heating of the folded protein or alternatively the assessment of ordered polymers from cell and animal models of disease or from the tissues of humans who carry the mutation. Copyright © 2010 Elsevier Inc. All rights reserved.

Preparation, characterisation and viability of encapsulated Trichoderma harzianum UPM40 in alginate-montmorillonite clay.

PubMed

Adzmi, Fariz; Meon, Sariah; Musa, Mohamed Hanafi; Yusuf, Nor Azah

2012-01-01

Microencapsulation is a process by which tiny parcels of an active ingredient are packaged within a second material for the purpose of shielding the active ingredient from the surrounding environment. This study aims to determine the ability of the microencapsulation technique to improve the viability of Trichoderma harzianum UPM40 originally isolated from healthy groundnut roots as effective biological control agents (BCAs). Alginate was used as the carrier for controlled release, and montmorillonite clay (MMT) served as the filler. The encapsulated Ca-alginate-MMT beads were characterised using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The FTIR results showed the interaction between the functional groups of alginate and MMT in the Ca-alginate-MMT beads. Peaks at 1595, 1420 and 1020 cm(-1) characterised alginate, and peaks at 1028 and 453 cm(-1) characterised MMT; both sets of peaks appeared in the Ca-alginate-MMT FTIR spectrum. The TGA analysis showed an improvement in the thermal stability of the Ca-alginate-MMT beads compared with the alginate beads alone. SEM analysis revealed a homogeneous distribution of the MMT particles throughout the alginate matrix. T. harzianum UPM40 was successfully encapsulated in the Ca-alginate-MMT beads. Storage analysis of the encapsulated T. harzianum UPM40 showed that the low storage temperature of 5°C resulted in significantly (p < 0.05) better storage compared with room temperature (30°C).

Characterisation of the human-seat coupling in response to vibration.

PubMed

Kim, Eunyeong; Fard, Mohammad; Kato, Kazuhito

2017-08-01

Characterising the coupling between the occupant and vehicle seat is necessary to understand the transmission of vehicle seat vibration to the human body. In this study, the vibration characteristics of the human body coupled with a vehicle seat were identified in frequencies up to 100 Hz. Transmissibilities of three volunteers seated on two different vehicle seats were measured under multi-axial random vibration excitation. The results revealed that the human-seat system vibration was dominated by the human body and foam below 10 Hz. Major coupling between the human body and the vehicle seat-structure was observed in the frequency range of 10-60 Hz. There was local coupling of the system dominated by local resonances of seat frame and seat surface above 60 Hz. Moreover, the transmissibility measured on the seat surface between the human and seat foam is suggested to be a good method of capturing human-seat system resonances rather than that measured on the human body in high frequencies above 10 Hz.Practitioner Summary: The coupling characteristics of the combined human body and vehicle seat system has not yet been fully understood in frequencies of 0.5-100 Hz. This study shows the human-seat system has distinctive dynamic coupling characteristics in three different frequency regions: below 10 Hz, 10-60 Hz, and above 60 Hz.

Robustness analysis of non-ordinary Petri nets for flexible assembly systems

NASA Astrophysics Data System (ADS)

Hsieh, Fu-Shiung

2010-05-01

Non-ordinary controlled Petri nets (NCPNs) have the advantages to model flexible assembly systems in which multiple identical resources may be required to perform an operation. However, existing studies on NCPNs are still limited. For example, the robustness properties of NCPNs have not been studied. This motivates us to develop an analysis method for NCPNs. Robustness analysis concerns the ability for a system to maintain operation in the presence of uncertainties. It provides an alternative way to analyse a perturbed system without reanalysis. In our previous research, we have analysed the robustness properties of several subclasses of ordinary controlled Petri nets. To study the robustness properties of NCPNs, we augment NCPNs with an uncertainty model, which specifies an upper bound on the uncertainties for each reachable marking. The resulting PN models are called non-ordinary controlled Petri nets with uncertainties (NCPNU). Based on NCPNU, the problem is to characterise the maximal tolerable uncertainties for each reachable marking. The computational complexities to characterise maximal tolerable uncertainties for each reachable marking grow exponentially with the size of the nets. Instead of considering general NCPNU, we limit our scope to a subclass of PN models called non-ordinary controlled flexible assembly Petri net with uncertainties (NCFAPNU) for assembly systems and study its robustness. We will extend the robustness analysis to NCFAPNU. We identify two types of uncertainties under which the liveness of NCFAPNU can be maintained.

[The concept of nuclear physics].

PubMed

Ducassou, D

1995-03-15

Understanding of the biological effects of radioactivity on living matter requires some basic notions of nuclear physics. The interreactions between living matter and ionising rays, emitted by natural or artificial radioelements, are responsible for such effects. These radioelements are characterised by the period, the nature and the energy of the rays they emit; they constitute the source of radiation whose effects generally depend on their activity.

Incorporating the Impacts of Small Scale Rock Heterogeneity into Models of Flow and Trapping in Target UK CO2 Storage Systems

NASA Astrophysics Data System (ADS)

Jackson, S. J.; Reynolds, C.; Krevor, S. C.

2017-12-01

Predictions of the flow behaviour and storage capacity of CO2 in subsurface reservoirs are dependent on accurate modelling of multiphase flow and trapping. A number of studies have shown that small scale rock heterogeneities have a significant impact on CO2flow propagating to larger scales. The need to simulate flow in heterogeneous reservoir systems has led to the development of numerical upscaling techniques which are widely used in industry. Less well understood, however, is the best approach for incorporating laboratory characterisations of small scale heterogeneities into models. At small scales, heterogeneity in the capillary pressure characteristic function becomes significant. We present a digital rock workflow that combines core flood experiments with numerical simulations to characterise sub-core scale capillary pressure heterogeneities within rock cores from several target UK storage reservoirs - the Bunter, Captain and Ormskirk sandstone formations. Measured intrinsic properties (permeability, capillary pressure, relative permeability) and 3D saturations maps from steady-state core flood experiments were the primary inputs to construct a 3D digital rock model in CMG IMEX. We used vertical end-point scaling to iteratively update the voxel by voxel capillary pressure curves from the average MICP curve; with each iteration more closely predicting the experimental saturations and pressure drops. Once characterised, the digital rock cores were used to predict equivalent flow functions, such as relative permeability and residual trapping, across the range of flow conditions estimated to prevail in the CO2 storage reservoirs. In the case of the Captain sandstone, rock cores were characterised across an entire 100m vertical transect of the reservoir. This allowed analysis of the upscaled impact of small scale heterogeneity on flow and trapping. Figure 1 shows the varying degree to which heterogeneity impacted flow depending on the capillary number in the Captain sandstone. At low capillary numbers, typical of regions where flow is dominated by buoyancy, fluid flow is impeded and trapping enhanced. At high capillary numbers, typical of the near wellbore environment, the fluid distributed homogeneously and the equivalent relative permeability was higher leading to improved injectivity.

Characterisation of potato crisp effective porosity using micro-CT.

PubMed

Renshaw, Ryan C; Robinson, John P; Dimitrakis, Georgios A; Bows, John R; Kingman, Samuel W

2016-10-01

The effective porosity is an important quantitative parameter for food products that has a significant effect on taste and quality. It is challenging to quantify the apparent porosity of fried potato crisps as they have a thin irregularly shaped cross section containing oil and water. This study uses a novel micro-CT technique to determine the solid volume fraction and hence the effective porosity of three types of potato crisps: standard continuously fried crisps, microwaved crisps, and continuously fried 'kettle' crisps. It was found that continuously fried kettle crisps had the lowest effective porosity at 0.54, providing the desired crunchy taste and lower oil contents. Crisps produced using a microwave process designed to mimic the dehydration process of standard continuous fried crisps had an effective porosity of 0.65, which was very similar to the effective porosity of 0.63 for standard continuously fried crisps. The results were supported by the findings of a forced preference consumer test. The effective porosity affects the product taste and is therefore a critical parameter. This study shows that micro-CT analysis can be used to characterise the change in effective porosity of a thin irregularly shaped food product, caused by a change of cooking procedure. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

The efficacy of (+)-Naltrexone on alcohol preference and seeking behaviour is dependent on light-cycle.

PubMed

Jacobsen, Jonathan Henry W; Buisman-Pijlman, Femke T A; Mustafa, Sanam; Rice, Kenner C; Hutchinson, Mark R

2018-01-01

Circadian rhythm affects drug-induced reward behaviour and the innate immune system. Peaks in reward-associated behaviour and immune responses typically occur during the active (dark) phase of rodents. While the role of the immune system, specifically, Toll-like receptor 4 (TLR4, an innate immune receptor) in drug-induced reward is becoming increasingly appreciated, it is unclear whether its effects vary according to light-cycle. Therefore, the aim of this study was to characterise the effects of the phase of the light-cycle and the state of the innate immune system on alcohol reward behaviour and subsequently determine whether the efficacy of targeting the immune component of drug reward depends upon the light-cycle. This study demonstrates that mice exhibit greater alcohol-induced conditioned place preference and alcohol two-bottle choice preference during the dark cycle. This effect overlapped with elevations in reward-, thirst- and immune-related genes. Administration of (+)-Naltrexone, a TLR4 antagonist, reduced immune-related gene mRNA expression and alcohol preference with its effects most pronounced during the dark cycle. However, (+)-Naltrexone, like other TLR4 antagonists exhibited off-target side effects, with a significant reduction in overall saccharin intake - an effect likely attributable to a reduction in tyrosine hydroxylase (Th) mRNA expression levels. Collectively, the study highlights a link between a time-of-day dependent influence of TLR4 on natural and alcohol reward-like behaviour in mice. Copyright © 2017 Elsevier Inc. All rights reserved.

Eutectic, monotectic and immiscibility systems of nimesulide with water-soluble carriers: phase equilibria, solid-state characterisation and in-vivo/pharmacodynamic evaluation.

PubMed

Abdelkader, Hamdy; Abdallah, Ossama Y; Salem, Hesham; Alani, Adam W G; Alany, Raid G

2014-10-01

The solid-state interactions of fused mixtures nimesulide (ND) with polyethylene glycol (PEG) 4000, urea or mannitol were studied through constructing thaw-melt phase equilibrium diagrams. The solid-state characteristics were investigated using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Various types of interactions were identified such as the formation of a eutectic system of ND-PEG 4000, monotectic system of ND-urea and complete solid immiscibility of ND with mannitol. The effects of carrier concentrations on the equilibrium solubility and in-vitro dissolution characteristics were studied. Linear increases (R(2)  > 0.99) in the aqueous solubility of ND in various concentrations of PEG 4000 and urea were obtained, whereas mannitol did not exhibit any effect on the solubility of ND. Similar trends were obtained with the dissolution efficiency of the fused mixtures of ND with PEG 4000 and urea compared with the corresponding physical mixtures and untreated drug. The analgesic effects of untreated ND and the selected formulations were investigated by evaluating the drug's ability to inhibit the acetic acid-induced writhing response. The analgesic effect of ND in a eutectic mixture with PEG 4000 and a monotectic mixture with urea was potentiated by 3.2 and 2.7-fold respectively compared with the untreated drug. © 2014 Royal Pharmaceutical Society.

Enhanced antioxidant effect of trans-resveratrol: potential of binary systems with polyethylene glycol and cyclodextrin.

PubMed

Moyano-Mendez, Josè Ramon; Fabbrocini, Gabriella; De Stefano, Daniela; Mazzella, Caterina; Mayol, Laura; Scognamiglio, Immacolata; Carnuccio, Rosa; Ayala, Fabio; La Rotonda, Maria Immacolata; De Rosa, Giuseppe

2014-10-01

Trans-resveratrol, a polyphenol extracted from Vitis vinifera, has different beneficial effects following its administration on the skin. Here the potential use of binary systems to enhance in vitro and in vivo activity of trans-resveratrol was investigated. Thus the aqueous solubility of trans-resveratrol was investigated in the presence of growing concentrations of polyethylene glycol (PEG) or β-cyclodextrin (βCD) as solubilizing excipients. Then, the solid dispersion of trans-resveratrol with PEG or inclusion complexes trans-resveratrol/βCD were prepared and characterised by different methods. Cytotoxicity and inhibition of reactive oxygen species (ROS) following H2O2 challenge in the presence of trans-resveratrol, alone or associated to the excipients, was evaluated on human keratinocyte HaCaT cell line. Both the trans-resveratrol-containing binary systems induced significant reduction of H2O2-induced ROS production, especially in the case of βCD that was selected for the following phase of the study. Thus, the effect of a cream containing trans-resveratrol, alone or associated to βCD, on different skin parameters such as corneometry, colorimetry and elastometry, was evaluated on human volunteers. All patients showed a visible improvement of clinical conditions with a remarkable decrease of aging signs, but this effect was higher of the hemi face treated with the βCD-containing formulation versus formulation containing trans-resveratrol alone.

Characterisation of the selective binding of antibiotics vancomycin and teicoplanin by the VanS receptor regulating type A vancomycin resistance in the enterococci.

PubMed

Hughes, C S; Longo, E; Phillips-Jones, M K; Hussain, R

2017-08-01

A-type resistance towards "last-line" glycopeptide antibiotic vancomycin in the leading hospital acquired infectious agent, the enterococci, is the most common in the UK. Resistance is regulated by the VanR A S A two-component system, comprising the histidine sensor kinase VanS A and the partner response regulator VanR A . The nature of the activating ligand for VanS A has not been identified, therefore this work sought to identify and characterise ligand(s) for VanS A . In vitro approaches were used to screen the structural and activity effects of a range of potential ligands with purified VanS A protein. Of the screened ligands (glycopeptide antibiotics vancomycin and teicoplanin, and peptidoglycan components N-acetylmuramic acid, D-Ala-D-Ala and Ala-D-y-Glu-Lys-D-Ala-D-Ala) only glycopeptide antibiotics vancomycin and teicoplanin were found to bind VanS A with different affinities (vancomycin 70μM; teicoplanin 30 and 170μM), and were proposed to bind via exposed aromatic residues tryptophan and tyrosine. Furthermore, binding of the antibiotics induced quicker, longer-lived phosphorylation states for VanS A , proposing them as activators of type A vancomycin resistance in the enterococci. Copyright © 2017 Diamond Light Source Ltd. Published by Elsevier B.V. All rights reserved.

Crystallisation of Ba1-xSrxZn2Si2O7 from BaO/SrO/ZnO/SiO2 glass with different ZrO2 and TiO2 concentrations

NASA Astrophysics Data System (ADS)

Vladislavova, Liliya; Kracker, Michael; Zscheckel, Tilman; Thieme, Christian; Rüssel, Christian

2018-04-01

The effect of different nucleation agents such as ZrO2 and TiO2 was investigated for a first time with respect to their crystallisation behaviour in the glass system BaO-SrO-ZnO-SiO2. In all studied glasses, a Ba1-xSrxZn2Si2O7 (0.1 ≤ x ≤ 0.9) solid solution crystallized. This phase was first described in 2015 to possess a similar structure as the high temperature phase of BaZn2Si2O7 and a thermal expansion close to zero or even negative. It may find applications e.g. as cook panels, telescope mirrors, and furnace windows. Kinetic parameters of the crystallisation process were determined by supplying different heating rates in a differential scanning calorimeter (DSC). The results were evaluated using the equations of Ozawa and Kissinger with respect to the activation energies. Furthermore, the Ozawa method was used for the determination of Avrami parameters, which provides further information on the nucleation and crystallisation processes. Scanning electron microscopy including electron backscatter diffraction (EBSD) was used to characterise the microstructure, to determine the crystallite size and the crystal orientation. For the characterisation of the occurring crystalline phases, X-ray diffraction was used.

Ellipsometric porosimetry on pore-controlled TiO2 layers

NASA Astrophysics Data System (ADS)

Rosu, Dana-Maria; Ortel, Erik; Hodoroaba, Vasile-Dan; Kraehnert, Ralph; Hertwig, Andreas

2017-11-01

The practical performance of surface coatings in applications like catalysis, water splitting or batteries depends critically on the coating materials' porosity. Determining the porosity in a fast and non-destructive way is still an unsolved problem for industrial thin-films technology. As a contribution to calibrated, non-destructive, optical layer characterisation, we present a multi-method comparison study on porous TiO2 films deposited by sol-gel synthesis on Si wafers. The ellipsometric data were collected on a range of samples with different TiO2 layer thickness and different porosity values. These samples were produced by templated sol-gel synthesis resulting in layers with a well-defined pore size and pore density. The ellipsometry measurement data were analysed by means of a Bruggeman effective medium approximation (BEMA), with the aim to determine the mixture ratio of void and matrix material by a multi-sample analysis strategy. This analysis yielded porosities and layer thicknesses for all samples as well as the dielectric function for the matrix material. Following the idea of multi-method techniques in metrology, the data was referenced to imaging by electron microscopy (SEM) and to a new EPMA (electron probe microanalysis) porosity approach for thin film analysis. This work might lead to a better metrological understanding of optical porosimetry and also to better-qualified characterisation methods for nano-porous layer systems.

Impact of low-trans fat compositions on the quality of conventional and fat-reduced puff pastry.

PubMed

Silow, Christoph; Zannini, Emanuele; Arendt, Elke K

2016-04-01

Four vegetable fat blends (FBs) with low trans-fatty acid (TFA ≤ 0.6 %) content with various ratios of palm stearin (PS) and rapeseed oil (RO) were characterised and examined for their application in puff pastry production. The amount of PS decreased from FB1 to FB4 and simultaneously the RO content increased. A range of analytical methods were used to characterise the FBs, including solid fat content (SFC), differential scanning calorimetry (DSC), cone penetrometry and rheological measurements. The internal and external structural quality parameters of baked puff pastry were investigated using texture analyser equipped with an Extended Craft Knife (ECK), VolScan and C-Cell image system. Puff pastry containing FB1 and FB2 achieved excellent baking results for full fat and fat-reduced puff pastry; hence these FBs contained adequate shortening properties. A fat reduction by 40 % using FB2 and a reduction of saturated fatty acids (SAFA) by 49 %, compared to the control, did not lead to adverse effects in lift and specific volume. The higher amount of RO and the lower SAFA content compared to FB1 coupled with the satisfying baking results makes FB2 the fat of choice in this study. FB3 and FB4 were found to be unsuitable for puff pastry production because of their melting behaviour.

Characterising an implementation intervention in terms of behaviour change techniques and theory: the 'Sepsis Six' clinical care bundle.

PubMed

Steinmo, Siri; Fuller, Christopher; Stone, Sheldon P; Michie, Susan

2015-08-08

Sepsis is a major cause of death from infection, with a mortality rate of 36 %. This can be halved by implementing the 'Sepsis Six' evidence-based care bundle within 1 h of presentation. A UK audit has shown that median implementation rates are 27-47 % and interventions to improve this have demonstrated minimal effects. In order to develop more effective implementation interventions, it is helpful to obtain detailed characterisations of current interventions and to draw on behavioural theory to identify mechanisms of change. The aim of this study was to illustrate this process by using the Behaviour Change Wheel; Behaviour Change Technique (BCT) Taxonomy; Capability, Opportunity, Motivation model of behaviour; and Theoretical Domains Framework to characterise the content and theoretical mechanisms of action of an existing intervention to implement Sepsis Six. Data came from documentary, interview and observational analyses of intervention delivery in several wards of a UK hospital. A broad description of the intervention was created using the Template for Intervention Description and Replication framework. Content was specified in terms of (i) component BCTs using the BCT Taxonomy and (ii) intervention functions using the Behaviour Change Wheel. Mechanisms of action were specified using the Capability, Opportunity, Motivation model and the Theoretical Domains Framework. The intervention consisted of 19 BCTs, with eight identified using all three data sources. The BCTs were delivered via seven functions of the Behaviour Change Wheel, with four ('education', 'enablement', 'training' and 'environmental restructuring') supported by the three data sources. The most frequent mechanisms of action were reflective motivation (especially 'beliefs about consequences' and 'beliefs about capabilities') and psychological capability (especially 'knowledge'). The intervention consisted of a wide range of BCTs targeting a wide range of mechanisms of action. This study demonstrates the utility of the Behaviour Change Wheel, the BCT Taxonomy and the Theoretical Domains Framework, tools recognised for providing guidance for intervention design, for characterising an existing intervention to implement evidence-based care.

Mechanical DT and NDT: characterisation of building stones and research of correlation for in situ analysis of ancient masonries

NASA Astrophysics Data System (ADS)

Vasanelli, E.; Calia, A.; Aiello, M. A.; Sileo, M.; Leucci, G.

2012-04-01

Restoration works of the historical-architectural built heritage move from the typological and mechanical qualification of the buildings. Minimum destructive impact is required in preliminary diagnostic studies for the interventions, as it is possible. The use of the undestructive and non-invasive diagnostic techniques has always advantages in the activities on pre-existing buildings, in terms of sustainability; moreover, it is a need with respect to the conservation constraints when we act on the historical-architectural heritage. This work deals with destructive and non-destructive tests for the mechanical characterisation of some traditional soft stones, used as building materials in the Southern Italy; it is a part of a larger activity devoted to set up non-invasive diagnostic procedures for the mechanical analysis and qualification of ancient masonries. The laboratory experimental activity is based on the use of mechanical compressive tests, ultrasonic and Schmidt-Hammer tests, and the research of correlation between the results obtained by these crossed tests. It is aimed to verify the effectiveness and/or to point out critical aspects and limits of the above mentioned non-destructive tests - already applied in the field of the concrete and compact stones - with reference to the characterisation of the soft stones. The research of correlations between the results of destructive and non destructive tests has the final aim to reduce the use of destructive analyses on the masonries, by acquiring substitutive information derivable from performing NDT in laboratory, as well as in situ conditions. Finally, data gathered by the mechanical characterisation give reference values for the evaluation and control of the effectiveness of restoration interventions and their monitoring. This activity is carried out in an interdisciplinary way within the AITECH network (Applied Innovation Technologies for Diagnosis and Conservation of Built Heritage), a regional research laboratory infrastructure (Apulian region, Southern Italy) funded within the FSE and FESR programs and realised by the contribution of the Italian CNR and Salento University.

Detection and characterisation of anthropogenic pieces by magnetic method

NASA Astrophysics Data System (ADS)

Nodot, Emilie; Munschy, Marc; Benevent, Pierre

2013-04-01

Human activities have let many anthropogenic objects buried under our feet. Some of these like explosive devices left after the World Wars turn out to be a threat to safety or environment. Others must be perfectly localised in case of construction work, for example gas pipe. Geophysics and more specifically magnetic cartography (many of these items are magnetic) can obviously help to locate them. We already use this method on daily basis to detect UXO (unexploded ordnance) but less than 10% of the unearthed objects are actually bombs or shells. Detection and mostly characterisation methods must be improved in order to reduce this proportion. On the field there are a few things we can do to increase data qualities. Characterisation may be improved by multiple scale prospections. We search a large area with our usual and rather fast method then we achieve high definition cartographies of small interesting areas (upon the object to characterise). In the case of measurements in an urban environment for example, data are distorted. The traffic (train, tramway, cars…) produces temporal variations of the magnetic field. This effect can be lessened, sometimes even removed by the use of a fixed scalar magnetic sensor. Data treatment is another key as regards the characterisation. Tools such as analytic signal or derivative are frequently used at the first degree. We will see that in a synthetic case the second and third degree bring even more information. A new issue appeared recently about pipes. Can we localise very precisely (less than 10 cm uncertainty) a gas pipe? Horizontally we can but due to our inversion method we still have troubles with the depth accuracy. Our final concern is about the amplitude of some anomalies. Potential methods equations are based on the fact that the anomaly norm must be minor to magnetic field norm. Sometimes this is not the case but vector magnetometry is a lead to solve this problem.

Quantifying bioalbedo: a new physically based model and discussion of empirical methods for characterising biological influence on ice and snow albedo

NASA Astrophysics Data System (ADS)

Cook, Joseph M.; Hodson, Andrew J.; Gardner, Alex S.; Flanner, Mark; Tedstone, Andrew J.; Williamson, Christopher; Irvine-Fynn, Tristram D. L.; Nilsson, Johan; Bryant, Robert; Tranter, Martyn

2017-11-01

The darkening effects of biological impurities on ice and snow have been recognised as a control on the surface energy balance of terrestrial snow, sea ice, glaciers and ice sheets. With a heightened interest in understanding the impacts of a changing climate on snow and ice processes, quantifying the impact of biological impurities on ice and snow albedo (bioalbedo) and its evolution through time is a rapidly growing field of research. However, rigorous quantification of bioalbedo has remained elusive because of difficulties in isolating the biological contribution to ice albedo from that of inorganic impurities and the variable optical properties of the ice itself. For this reason, isolation of the biological signature in reflectance data obtained from aerial/orbital platforms has not been achieved, even when ground-based biological measurements have been available. This paper provides the cell-specific optical properties that are required to model the spectral signatures and broadband darkening of ice. Applying radiative transfer theory, these properties provide the physical basis needed to link biological and glaciological ground measurements with remotely sensed reflectance data. Using these new capabilities we confirm that biological impurities can influence ice albedo, then we identify 10 challenges to the measurement of bioalbedo in the field with the aim of improving future experimental designs to better quantify bioalbedo feedbacks. These challenges are (1) ambiguity in terminology, (2) characterising snow or ice optical properties, (3) characterising solar irradiance, (4) determining optical properties of cells, (5) measuring biomass, (6) characterising vertical distribution of cells, (7) characterising abiotic impurities, (8) surface anisotropy, (9) measuring indirect albedo feedbacks, and (10) measurement and instrument configurations. This paper aims to provide a broad audience of glaciologists and biologists with an overview of radiative transfer and albedo that could support future experimental design.

Multifunctional energy landscape for a DNA G-quadruplex: An evolved molecular switch

NASA Astrophysics Data System (ADS)

Cragnolini, Tristan; Chakraborty, Debayan; Šponer, Jiří; Derreumaux, Philippe; Pasquali, Samuela; Wales, David J.

2017-10-01

We explore the energy landscape for a four-fold telomere repeat, obtaining interconversion pathways between six experimentally characterised G-quadruplex topologies. The results reveal a multi-funnel system, with a variety of intermediate configurations and misfolded states. This organisation is identified with the intrinsically multi-functional nature of the system, suggesting a new paradigm for the classification of such biomolecules and clarifying issues regarding apparently conflicting experimental results.

Impact resistance performance of diamond film on a curved molybdenum substrate

NASA Astrophysics Data System (ADS)

Chen, Yang; Gou, Li

2017-08-01

Diamond films with different thicknesses were deposited on flat and curved molybdenum substrate by the microwave plasma chemical vapour deposition (MPCVD) method. Scanning electronic microscopy, atomic force microscopy and Raman spectroscopy were employed to characterise the morphology, the surface roughness and the composition of the films, respectively. A NanoTest system was used for hardness, elastic modulus and nanoimpact tests. The curved surface and ductility of the molybdenum substrate allow large deformation for the thinner films. The substrate has less effect on impact for the thicker film, the deformation of which is mainly determined by the film composition. Under a load of 50 mN and 75 cycles, less deformation occurred for the 22 μm thick film on the curved molybdenum substrate.

Finite-time stability of neutral-type neural networks with random time-varying delays

NASA Astrophysics Data System (ADS)

Ali, M. Syed; Saravanan, S.; Zhu, Quanxin

2017-11-01

This paper is devoted to the finite-time stability analysis of neutral-type neural networks with random time-varying delays. The randomly time-varying delays are characterised by Bernoulli stochastic variable. This result can be extended to analysis and design for neutral-type neural networks with random time-varying delays. On the basis of this paper, we constructed suitable Lyapunov-Krasovskii functional together and established a set of sufficient linear matrix inequalities approach to guarantee the finite-time stability of the system concerned. By employing the Jensen's inequality, free-weighting matrix method and Wirtinger's double integral inequality, the proposed conditions are derived and two numerical examples are addressed for the effectiveness of the developed techniques.

Burning Mouth Syndrome: Aetiopathogenesis and Principles of Management

PubMed Central

Fourie, J.; Bouckaert, M.; Ballyram, R.; Lemmer, J.

2017-01-01

Burning mouth syndrome (BMS) is a chronic debilitating oral condition characterised by a burning sensation of the oral mucosa in an otherwise apparently normal person. Its aetiology and pathogenesis are obscure, but both psychogenic factors and peripheral and central neuropathies appear to be implicated. There is no cure for BMS, and treatment with either local or systemic medications focuses on the relief of symptoms and on improving quality of life. In recalcitrant cases, psychological/psychiatric intervention may be helpful. In order to improve treatment outcomes, a better understanding of the pathogenesis of this syndrome might provide a basis for the development of more effective management strategies. In this short review, we discuss current knowledge of the diagnosis, aetiopathogenesis, and management of BMS. PMID:29180911

Burning Mouth Syndrome: Aetiopathogenesis and Principles of Management.

PubMed

Feller, L; Fourie, J; Bouckaert, M; Khammissa, R A G; Ballyram, R; Lemmer, J

2017-01-01

Burning mouth syndrome (BMS) is a chronic debilitating oral condition characterised by a burning sensation of the oral mucosa in an otherwise apparently normal person. Its aetiology and pathogenesis are obscure, but both psychogenic factors and peripheral and central neuropathies appear to be implicated. There is no cure for BMS, and treatment with either local or systemic medications focuses on the relief of symptoms and on improving quality of life. In recalcitrant cases, psychological/psychiatric intervention may be helpful. In order to improve treatment outcomes, a better understanding of the pathogenesis of this syndrome might provide a basis for the development of more effective management strategies. In this short review, we discuss current knowledge of the diagnosis, aetiopathogenesis, and management of BMS.

Energy characterisation of ultrasonic systems for industrial processes.

PubMed

Al-Juboori, Raed A; Yusaf, Talal; Bowtell, Leslie; Aravinthan, Vasantha

2015-03-01

Obtaining accurate power characteristics of ultrasonic treatment systems is an important step towards their industrial scalability. Calorimetric measurements are most commonly used for quantifying the dissipated ultrasonic power. However, accuracy of these measurements is affected by various heat losses, especially when working at high power densities. In this work, electrical power measurements were conducted at all locations in the piezoelectric ultrasonic system equipped with ½″ and ¾″ probes. A set of heat transfer calculations were developed to estimate the convection heat losses from the reaction solution. Chemical dosimeters represented by the oxidation of potassium iodide, Fricke solution and 4-nitrophenol were used to chemically correlate the effect of various electrical amplitudes and treatment regimes. This allowed estimation of sonochemical-efficiency (SE) and energy conversion (XUS) of the ultrasonic system. Results of this study showed overall conversion efficiencies of 60-70%. This correlated well with the chemical dosimeter yield curves of both organic and inorganic aqueous solutions. All dosimeters showed bubble shielding and coalescence effects at higher ultrasonic power levels, less pronounced for the ½″ probe case. SE and XUS values in the range of 10(-10) mol/J and 10(-3) J/J respectively confirmed that conversion of ultrasonic power to chemical yield declined with amplitude. Copyright © 2014 Elsevier B.V. All rights reserved.

The Bright Elusive Butterfly of Value in Health Technology Development

PubMed Central

Greenhalgh, Trisha; Fahy, Nick; Shaw, Sara

2018-01-01

The current system of health technology development is characterised by multiple misalignments. The "supply" side (innovation policy-makers, entrepreneurs, investors) and the "demand" side (health policy-makers, regulators, health technology assessment, purchasers) operate under different – and conflicting – logics. The system is less a "pathway" than an unstable ecosystem of multiple interacting sub-systems. "Value" means different things to each of the numerous actors involved. Supply-side dynamics are built on fictions; regulatory checks and balances are designed to assure quality, safety and efficacy, not to ensure that technologies entering the market are either desirable or cost-effective. Assessment of comparative and cost-effectiveness usually comes too late in the process to shape an innovation’s development. We offer no simple solutions to these problems, but in the spirit of commencing a much-needed public debate, we suggest some tentative ways forward. First, universities and public research funders should play a more proactive role in shaping the system. Second, the role of industry in forging long-term strategic partnerships for public benefit should be acknowledged (though not uncritically). Third, models of "responsible innovation" and public input to research priority-setting should be explored. Finally, the evidence base on how best to govern inter-sectoral health research partnerships should be developed and applied. PMID:29325407

Epidermal skin grafting in vitiligo: a pilot study.

PubMed

Janowska, Agata; Dini, Valentina; Panduri, Salvatore; Macchia, Michela; Oranges, Teresa; Romanelli, Marco

2016-09-01

Vitiligo is a multifactorial acquired dermatosis characterised by achromic or hypochromic macules and by the absence of functioning melanocytes. Treatment depends on the extent of the affected areas and on disease activity. Surgical techniques have proven to be effective in stable cases but can be time-consuming and, in some cases, aesthetically unsatisfying or painful for the patients. The aim of the study was to assess the clinical safety and effectiveness of a new automatic epidermal skin harvesting device in patients with stable localised vitiligo over a minimum 12-month period. This new system (CELLUTOME™ Epidermal Harvesting System, KCI, an ACELITY Company, San Antonio, TX) is a commercially available epidermal skin harvesting system that can be used without local anaesthesia or other pre-treatments and has been shown to have low rates of donor site morbidity. Epidermal skin grafts can used in patients with acute and hard to heal chronic wounds, burns and stable vitiligo. The use of advanced therapies may improve the quality of life, have cost benefits and accelerate re-pigmentation of patients with vitiligo. In our preliminary study, this system was seen to be a safe and efficacious means of harvesting epidermal micrografts containing melanocytes for use in patients with stable vitiligo unresponsive to standard therapies. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Inflation with a massive vector field nonminimally coupled to gravity

NASA Astrophysics Data System (ADS)

Páramos, J.

2018-01-01

The possibility that inflation is driven by a massive vector field with SO(3) global symmetry nonminimally coupled to gravity is presented. Through an appropriate Ansatz for the vector field, the behaviour of the equations of motion is studied through the ensuing dynamical system, focusing on the characterisation of the ensuing fixed points.

Is the University System in Australia Producing Deep Thinkers?

ERIC Educational Resources Information Center

Lake, Warren W.; Boyd, William E.

2015-01-01

Teaching and learning research since the 1980s has established a trend in students' learning approach tendencies, characterised by decreasing surface learning and increasing deep learning with increasing age. This is an important trend in higher education, especially at a time of increasing numbers of older students: are we graduating more deep…

Canola integration into semi-arid wheat cropping systems of the inland Pacific Northwestern USA

USDA-ARS?s Scientific Manuscript database

The inland Pacific Northwestern USA (iPNW) wheat-producing region has a diversity of environments and soils, yet it lacks crop diversity and is one of the few semi-arid wheat-growing regions without significant integration of oilseeds. Four major agroecological zones, primarily characterised by wate...

NCEP-ECPC monthly to seasonal US fire danger forecasts

Treesearch

J. Roads; P. Tripp; H. Juang; J. Wang; F. Fujioka; S. Chen

2010-01-01

Five National Fire Danger Rating System indices (including the Ignition Component, Energy Release Component, Burning Index, Spread Component, and the Keetch–Byram Drought Index) and the Fosberg Fire Weather Index are used to characterise US fire danger. These fire danger indices and input meteorological variables, including temperature, relative humidity, precipitation...

The Professional Learning of Teachers in Higher Education

ERIC Educational Resources Information Center

Knight, Peter; Tait, Jo; Yorke, Mantz

2006-01-01

Educational professional development is a global concern. It is often characterised by event-delivery methods, though there are signs that other approaches are gaining favour. The authors stress the significance of non-formal learning, and the ways in which it can be promoted and enhanced within the activity systems within which teachers in higher…

Teacher Education in TVET: Developing a New Paradigm

ERIC Educational Resources Information Center

Majumdar, Shyamal

2011-01-01

The 21st century has been characterised by changes in the economy, the nature of society and situations in the ecological environment. Teaching and learning processes have never been the same since the demand for work-related competencies, the type of information available and the way that education and training systems must be implemented must…

UMTS signal measurements with digital spectrum analysers.

PubMed

Licitra, G; Palazzuoli, D; Ricci, A S; Silvi, A M

2004-01-01

The launch of the Universal Mobile Telecommunications System (UMTS), the most recent mobile telecommunications standard has imposed the requirement of updating measurement instrumentation and methodologies. In order to define the most reliable measurement procedure, which is aimed at assessing the exposure to electromagnetic fields, modern spectrum analysers' features for correct signal characterisation has been reviewed.

Lecture-Recording Technology in Higher Education: Exploring Lecturer and Student Views across the Disciplines

ERIC Educational Resources Information Center

Dona, Kulari Lokuge; Gregory, Janet; Pechenkina, Ekaterina

2017-01-01

This paper presents findings of an institutional case study investigating how students and lecturers experienced a new opt-out, fully integrated lecture-recording system which enabled audio and presentation screen capture. The study's focus is on how "traditional" students (generally characterised as young, enrolled full-time and…

The Process and Product: Crafting Community Portraits with Young People in Flexible Learning Settings

ERIC Educational Resources Information Center

Baker, Alison M.

2016-01-01

Community-based alternative education is situated on the margins in relation to mainstream education. Young people attending these learning sites are often characterised as "disengaged learners", who have fallen through the cracks of the traditional schooling system. The aim of this project was to use participatory visual methods with…

Education and Education Research: Moribund Fields or Dynamic Interacting Systems?

ERIC Educational Resources Information Center

Reddy, C.

2011-01-01

The complex field of education is often depicted as a static field governed by technocratic approaches to activities that characterise the field. Education change is equally viewed in such limited and positivistic ways and linear means-end processes (Hoban 2002). In such orientations to the field, educational research therefore, is about finding…

Family Background and University Dropouts during the Crisis: The Case of Italy

ERIC Educational Resources Information Center

Ghignoni, Emanuela

2017-01-01

The Italian university system has long been characterised by high non-completion rates, though aggregate data show a slight reduction of dropouts in recent years. The most straightforward theoretical explanation for this lies in the lowering opportunity cost of studying due to the financial and economic crisis. Nonetheless, this interpretation is…

Reinventing "Inclusion": New Labour and the Cultural Politics of Special Education

ERIC Educational Resources Information Center

Armstrong, Derrick

2005-01-01

New Labour has placed inclusion at the centre of its educational agenda. Its policies have been characterised by an attempt to include disabled children, together with others identified as having "special educational needs", within the ordinary school system and the shifting of responsibility for meeting their needs to teachers in the…

Child Well-Being in Flanders: A Multidimensional Account

ERIC Educational Resources Information Center

Ghysels, Joris; Van Vlasselaer, Evelien

2008-01-01

In this article we characterise the well-being of young children in the Belgian region of Flanders. We focus on three commonly used indicators: educational attainment, the existence of special needs and the occurrence of problematic behaviour. The former derives from a relatively impartial source, the schooling system, while the latter two…

Variability and Reliabiltiy in Axon Growth Cone Navigation Decision Making

NASA Astrophysics Data System (ADS)

Garnelo, Marta; Ricoult, Sébastien G.; Juncker, David; Kennedy, Timothy E.; Faisal, Aldo A.

2015-03-01

The nervous system's wiring is a result of axon growth cones navigating through specific molecular environments during development. In order to reach their target, growth cones need to make decisions under uncertainty as they are faced with stochastic sensory information and probabilistic movements. The overall system therefore exhibits features of whole organisms (perception, decision making, action) in the subset of a single cell. We aim to characterise growth cone navigation in defined nano-dot guidance cue environments, by using the tools of computational neuroscience to conduct ``molecular psychophysics.'' We start with a generative model of growth cone behaviour and we 1. characterise sensory and internal sources of noise contributing to behavioural variables, by combining knowledge of the underlying stochastic dynamics in cue sensing and the growth of the cytoskeleton. This enables us to 2. produce bottom-up lower limit estimates of behavioural response reliability and visualise it as probability distributions over axon growth trajectories. Given this information we can match our in silico model's ``psychometric'' decision curves with empirical data. Finally we use a Monte-Carlo approach to predict response distributions of axon trajectories from our model.

Comparative study of the bioconversion process using R-(+)- and S-(-)-limonene as substrates for Fusarium oxysporum 152B.

PubMed

Molina, Gustavo; Bution, Murillo L; Bicas, Juliano L; Dolder, Mary Anne Heidi; Pastore, Gláucia M

2015-05-01

This study compared the bioconversion process of S-(-)-limonene into limonene-1,2-diol with the already established biotransformation of R-(+)-limonene into α-terpineol using the same biocatalyst in both processes, Fusarium oxysporum 152B. The bioconversion of the S-(-)-isomer was tested on cell permeabilisation under anaerobic conditions and using a biphasic system. When submitted to permeabilisation trials, this biocatalyst has shown a relatively high resistance; still, no production of limonene-1,2-diol and a loss of activity of the biocatalyst were observed after intense cell treatment, indicating a complete loss of cell viability. Furthermore, the results showed that this process can be characterised as an aerobic system that was catalysed by limonene-1,2-epoxide hydrolase, had an intracellular nature and was cofactor-dependent because the final product was not detected by an anaerobic process. Finally, this is the first report to characterise the bioconversion of R-(+)- and S-(-)-limonene by cellular detoxification using ultra-structural analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dependence of Impedance of Embedded Single Cells on Cellular Behaviour

PubMed Central

Cho, Sungbo; Castellarnau, Marc; Samitier, Josep; Thielecke, Hagen

2008-01-01

Non-invasive single cell analyses are increasingly required for the medical diagnostics of test substances or the development of drugs and therapies on the single cell level. For the non-invasive characterisation of cells, impedance spectroscopy which provides the frequency dependent electrical properties has been used. Recently, microfludic systems have been investigated to manipulate the single cells and to characterise the electrical properties of embedded cells. In this article, the impedance of partially embedded single cells dependent on the cellular behaviour was investigated by using the microcapillary. An analytical equation was derived to relate the impedance of embedded cells with respect to the morphological and physiological change of extracellular interface. The capillary system with impedance measurement showed a feasibility to monitor the impedance change of embedded single cells caused by morphological and physiological change of cell during the addition of DMSO. By fitting the derived equation to the measured impedance of cell embedded at different negative pressure levels, it was able to extrapolate the equivalent gap and gap conductivity between the cell and capillary wall representing the cellular behaviour. PMID:27879760

An experimental evaluation of an effective medium based compaction equation.

PubMed

Mahmoodi, Foad; Alderborn, Göran; Frenning, Göran

2012-05-12

Tablet production involves compression of free flowing powder in an enclosed cavity of defined geometry. The complexity of the powder bed system necessitates that a way be found to better understand what occurs during compression. One such approach is by means of compaction equations, of which, the Heckel and Kawakita equations are the best known. This work attempts to experimentally evaluate the applicability of the effective medium (EM) equation introduced by Frenning et al. (2009) to powder systems. Two powder types (sodium chloride and lactose monohydrate), each consisting of three size fractions (<40, 125-212 and 212-300μm) were characterised and compressed to a pressure of 500MPa. These powders were chosen because of their differing mechanical properties. An invariance which is inherent in the EM equation is exposed by varying the starting points of compression, and can yield insights into compression mechanisms. Such invariant regions were observed once plastic particle deformation started to dominate the compression behaviour, and enabled the determination of the point where particle rearrangement stops. Copyright © 2012 Elsevier B.V. All rights reserved.

Monitoring of diesel engine combustions based on the acoustic source characterisation of the exhaust system

NASA Astrophysics Data System (ADS)

Jiang, J.; Gu, F.; Gennish, R.; Moore, D. J.; Harris, G.; Ball, A. D.

2008-08-01

Acoustic methods are among the most useful techniques for monitoring the condition of machines. However, the influence of background noise is a major issue in implementing this method. This paper introduces an effective monitoring approach to diesel engine combustion based on acoustic one-port source theory and exhaust acoustic measurements. It has been found that the strength, in terms of pressure, of the engine acoustic source is able to provide a more accurate representation of the engine combustion because it is obtained by minimising the reflection effects in the exhaust system. A multi-load acoustic method was then developed to determine the pressure signal when a four-cylinder diesel engine was tested with faults in the fuel injector and exhaust valve. From the experimental results, it is shown that a two-load acoustic method is sufficient to permit the detection and diagnosis of abnormalities in the pressure signal, caused by the faults. This then provides a novel and yet reliable method to achieve condition monitoring of diesel engines even if they operate in high noise environments such as standby power stations and vessel chambers.

Effect of management (organic vs conventional) on volatile profiles of six plum cultivars (Prunus salicina Lindl.). A chemometric approach for varietal classification and determination of potential markers.

PubMed

Cuevas, F J; Moreno-Rojas, J M; Arroyo, F; Daza, A; Ruiz-Moreno, M J

2016-05-15

The volatile profiles of six plum cultivars ('Laetitia', 'Primetime', 'Sapphire', 'Showtime', 'Songold' and 'Souvenir') produced under two management systems (conventional and organic) and harvested in two consecutive years were obtained by HS-SPME-GC-MS. Twenty-five metabolites were determined, five of which (pentanal, (E)-2-heptenal, 1-octanol, eucalyptol and 2-pentylfuran) are reported for the first time in Prunus salicina Lindl. Hexanal stood out as a major volatile compound affected by the management system. In addition, partial least square discriminant analysis (PLS-DA) achieved an effective classification of genotypes based on their volatile profiles. A high classification accuracy model was obtained with a sensitivity of 97.9% and a specificity of 99.6%. Furthermore, the application of a dual criterion, based on a method of variable selection, VIP (variable importance in projection) and the results of a univariate analysis (ANOVA), allowed the identification of potential volatile markers in 'Primetime', 'Showtime' and 'Souvenir' genotypes (cultivars not characterised to date). Copyright © 2015 Elsevier Ltd. All rights reserved.

Microbial Community Dynamics and Response to Plant Growth-Promoting Microorganisms in the Rhizosphere of Four Common Food Crops Cultivated in Hydroponics.

PubMed

Sheridan, C; Depuydt, P; De Ro, M; Petit, C; Van Gysegem, E; Delaere, P; Dixon, M; Stasiak, M; Aciksöz, S B; Frossard, E; Paradiso, R; De Pascale, S; Ventorino, V; De Meyer, T; Sas, B; Geelen, D

2017-02-01

Plant growth promoting microorganisms (PGPMs) of the plant root zone microbiome have received limited attention in hydroponic cultivation systems. In the framework of a project aimed at the development of a biological life support system for manned missions in space, we investigated the effects of PGPMs on four common food crops (durum and bread wheat, potato and soybean) cultivated in recirculating hydroponic systems for a whole life cycle. Each crop was inoculated with a commercial PGPM mixture and the composition of the microbial communities associated with their root rhizosphere, rhizoplane/endosphere and with the recirculating nutrient solution was characterised through 16S- and ITS-targeted Illumina MiSeq sequencing. PGPM addition was shown to induce changes in the composition of these communities, though these changes varied both between crops and over time. Microbial communities of PGPM-treated plants were shown to be more stable over time. Though additional development is required, this study highlights the potential benefits that PGPMs may confer to plants grown in hydroponic systems, particularly when cultivated in extreme environments such as space.

Characterisation and calculation of nonlinear vibrations in gas foil bearing systems-An experimental and numerical investigation

NASA Astrophysics Data System (ADS)

Hoffmann, Robert; Liebich, Robert

2018-01-01

This paper states a unique classification to understand the source of the subharmonic vibrations of gas foil bearing (GFB) systems, which will experimentally and numerically tested. The classification is based on two cases, where an isolated system is assumed: Case 1 considers a poorly balance rotor, which results in increased displacement during operation and interacts with the nonlinear progressive structure. It is comparable to a Duffing-Oscillator. In contrast, for case 2 a well/perfectly balanced rotor is assumed. Hence, the only source of nonlinear subharmonic whirling results from the fluid film self-excitation. Experimental tests with different unbalance levels and GFB modifications confirm these assumptions. Furthermore, simulations are able to predict the self-excitations and synchronous and subharmonic resonances of the experimental test. The numerical model is based on a linearised eigenvalue problem. The GFB system uses linearised stiffness and damping parameters by applying a perturbation method on the Reynolds Equation. The nonlinear bump structure is simplified by a link-spring model. It includes Coulomb friction effects inside the elastic corrugated structure and captures the interaction between single bumps.

Channel characterisation for future Ka-band Mobile Satellite Systems and preliminary results

NASA Technical Reports Server (NTRS)

Sforza, Mario; Buonomo, Sergio; Arbesser-Rastburg, Bertram

1994-01-01

Mobile satellite systems (MSS) are presently designed or planned to operate, with the exception of OMNITRACKS, in the lower part of the frequency spectrum (UHF to S-bands). The decisions taken at the last World Administrative Radio Conference in 1992 to increase the allocated L- and S-bands for MSS services will only partly alleviate the problem of system capacity. In addition the use of L-and S-band frequencies generally requires large antenna apertures on board the satellite terminal side. The idea of exploiting the large spectrum resources available at higher frequencies (20-30 GHz) and the perspective of reducing user terminal size (and possibly price too) have spurred the interest of systems designers and planners. On the other hand, Ka-band frequencies suffer from increased slant path losses due to atmospheric attenuation phenomena. The European Space Agency (ESA) has recently embarked on a number of activities aimed at studying the effect of the typical mobile propagation impairments at Ka-band. This paper briefly summarizes ESA efforts in this field of research and presents preliminary experimental results.

Non-destructive analysis of flake properties in automotive paints with full-field optical coherence tomography and 3D segmentation.

PubMed

Zhang, Jinke; Williams, Bryan M; Lawman, Samuel; Atkinson, David; Zhang, Zijian; Shen, Yaochun; Zheng, Yalin

2017-08-07

Automotive coating systems are designed to protect vehicle bodies from corrosion and enhance their aesthetic value. The number, size and orientation of small metallic flakes in the base coat of the paint has a significant effect on the appearance of automotive bodies. It is important for quality assurance (QA) to be able to measure the properties of these small flakes, which are approximately 10μm in radius, yet current QA techniques are limited to measuring layer thickness. We design and develop a time-domain (TD) full-field (FF) optical coherence tomography (OCT) system to scan automotive panels volumetrically, non-destructively and without contact. We develop and integrate a segmentation method to automatically distinguish flakes and allow measurement of their properties. We test our integrated system on nine sections of five panels and demonstrate that this integrated approach can characterise small flakes in automotive coating systems in 3D, calculating the number, size and orientation accurately and consistently. This has the potential to significantly impact QA testing in the automotive industry.

Highlights from the HIV Cure and Reservoir Symposium, 11-12 September 2017, Ghent, Belgium.

PubMed

Kint, Sam; Van Hecke, Clarissa; Cole, Basiel; Vandekerckhove, Linos; Sips, Magdalena

2018-01-01

For the second time, the HIV Cure Research Center (HCRC) at Ghent University organised the HIV Cure and Reservoir Symposium, in Ghent, Belgium, where in this two-day conference, virologists, molecular biologists, immunologists and clinicians presented the most recent achievements in the field of HIV cure, including data on therapeutic vaccines, HIV remission strategies such as 'shock and kill' or 'block and lock', benefits of early ART and potential of haematopoietic stem cell transplant in achieving cure. Furthermore, methods to characterise and quantify the HIV reservoir were discussed along with HIV reservoir characterisation in different body parts, including the central nervous system. An HIV activist and representative of a patients' agency also presented the patients' perspective on HIV cure. This report is a summary of all topics discussed during this symposium.

Experimentelles FMCW-Radar zur hochfrequenten Charakterisierung von Windenergieanlagen

NASA Astrophysics Data System (ADS)

Schubert, Karsten; Werner, Jens; Schwartau, Fabian

2017-09-01

During the increasing dissemination of renewable energy sources the potential and actual interference effects of wind turbine plants became obvious. Turbines reflect the signals of weather radar and other radar systems. In addition to the static radar echoes, in particular the Doppler echoes are to be mentioned as an undesirable impairment Keränen (2014). As a result, building permit is refused for numerous new wind turbines, as the potential interference can not be reliably predicted. As a contribution to the improvement of this predictability, measurements are planned which aim at the high-frequency characterisation of wind energy installations. In this paper, a cost-effective FMCW radar is presented, which is operated in the same frequency band (C-band) as the weather radars of the German weather service. Here, the focus is on the description of the hardware design including the considerations used for its dimensioning.

The contribution of a gender perspective to the understanding of migrants' health

PubMed Central

Llácer, Alicia; Zunzunegui, María Victoria; del Amo, Julia; Mazarrasa, Lucía; Bolůmar, Francisco

2007-01-01

In 2005 women represented approximately half of all 190 million international migrants worldwide. This paper addresses the need to integrate a gender perspective into epidemiological studies on migration and health, outlines conceptual gaps and discusses some methodological problems. We mainly consider the international voluntary migrant. Women may emigrate as wives or as workers in a labour market in which they face double segregation, both as migrants and as women. We highlight migrant women's heightened vulnerability to situations of violence, as well as important gaps in our knowledge of the possible differential health effects of factors such as poverty, unemployment, social networks and support, discrimination, health behaviours and use of services. We provide an overview of the problems of characterising migrant populations in the health information systems, and of possible biases in the health effects caused by failure to take the triple dimension of gender, social class and ethnicity into account. PMID:18000117

Fretting corrosion of CoCr alloy: Effect of load and displacement on the degradation mechanisms.

PubMed

Bryant, Michael; Neville, Anne

2017-02-01

Fretting corrosion of medical devices is of growing concern, yet, the interactions between tribological and electrochemical parameters are not fully understood. Fretting corrosion of CoCr alloy was simulated, and the components of damage were monitored as a function of displacement and contact pressure. Free corrosion potential (E corr ), intermittent linear polarisation resistance and cathodic potentiostatic methods were used to characterise the system. Interferometry was used to estimate material loss post rubbing. The fretting regime influenced the total material lost and the dominant degradation mechanism. At high contact pressures and low displacements, pure corrosion was dominant with wear and its synergies becoming more important as the contact pressure and displacement decreased and increased, respectively. In some cases, an antagonistic effect from the corrosion-enhanced wear contributor was observed suggesting that film formation and removal may be present. The relationship between slip mechanism and the contributors to tribocorrosion degradation is presented.

Benefits of Exercise in Rheumatoid Arthritis

PubMed Central

Cooney, Jennifer K.; Law, Rebecca-Jane; Matschke, Verena; Lemmey, Andrew B.; Moore, Jonathan P.; Ahmad, Yasmeen; Jones, Jeremy G.; Maddison, Peter; Thom, Jeanette M.

2011-01-01

This paper aims to highlight the importance of exercise in patients with rheumatoid arthritis (RA) and to demonstrate the multitude of beneficial effects that properly designed exercise training has in this population. RA is a chronic, systemic, autoimmune disease characterised by decrements to joint health including joint pain and inflammation, fatigue, increased incidence and progression of cardiovascular disease, and accelerated loss of muscle mass, that is, “rheumatoid cachexia”. These factors contribute to functional limitation, disability, comorbidities, and reduced quality of life. Exercise training for RA patients has been shown to be efficacious in reversing cachexia and substantially improving function without exacerbating disease activity and is likely to reduce cardiovascular risk. Thus, all RA patients should be encouraged to include aerobic and resistance exercise training as part of routine care. Understanding the perceptions of RA patients and health professionals to exercise is key to patients initiating and adhering to effective exercise training. PMID:21403833

Development of a Methodology for the Characterisation of Air-coupled Ultrasound Probes

NASA Astrophysics Data System (ADS)

Pietroni, Paolo; Marco Revel, Gian

2010-05-01

This study is aimed at developing a technique for the characterisation of air-coupled ultrasound probes, starting from the analysis of the mechanical behaviour of the probe membrane. The vibratory behaviour of the emission membrane is studied using laser-Doppler vibrometry techniques with high frequency demodulation system (20 MHz). The determination of the vibration provides information which are useful for the assessment of the performance of the probe, in particular concerning the Quality factor and the portion of the membrane which really contributes to the emission. During the second step the results of the vibration measurements are used to calculate, by means of numerical boundary element method, the ultrasound beam emitted in terms of intensity in space. The obtained field is compared with the direct measurements carried out by scanning with the receiver probe and a pinhole plate. This comparison allows the potential and the problems of the two different characterisation techniques to be determined, even if the pinhole technique (which is currently considered the state of the art) cannot be used as an absolute reference. This study appears to be useful for paving the way for a new methodology for the calibration of air-coupled ultrasound probes, which potentially could be used not only to improve the probe manufacturing process, but also to control conformity to specifications.

Diagnostic accuracy of translucency rendering to differentiate polyps from pseudopolyps at 3D endoluminal CT colonography: a feasibility study.

PubMed

Guerrisi, A; Marin, D; Laghi, A; Di Martino, M; Iafrate, F; Iannaccone, R; Catalano, C; Passariello, R

2010-08-01

The aim of this study was to assess the accuracy of translucency rendering (TR) in computed tomographic (CT) colonography without cathartic preparation using primary 3D reading. From 350 patients with 482 endoscopically verified polyps, 50 pathologically proven polyps and 50 pseudopolyps were retrospectively examined. For faecal tagging, all patients ingested 140 ml of orally administered iodinated contrast agent (diatrizoate meglumine and diatrizoate sodium) at meals 48 h prior to CT colonography examination and two h prior to scanning. CT colonography was performed using a 64-section CT scanner. Colonoscopy with segmental unblinding was performed within 2 weeks after CT. Three independent radiologists retrospectively evaluated TRCT clonographic images using a dedicated software package (V3D-Colon System). To enable size-dependent statistical analysis, lesions were stratified into the following size categories: small (< or =5 mm), intermediate (6-9 mm), and large (> or =10 mm). Overall average TR sensitivity for polyp characterisation was 96.6%, and overall average specificity for pseudopolyp characterisation was 91.3%. Overall average diagnostic accuracy (area under the curve) of TR for characterising colonic lesions was 0.97. TR is an accurate tool that facilitates interpretation of images obtained with a primary 3D analysis, thus enabling easy differentiation of polyps from pseudopolyps.

Molecular characterisation of measles virus strains among refugees from Central African Republic in Cameroon in 2014.

PubMed

Ndombo, P K; Ndze, V N; Mbarga, F D; Anderson, R; Acho, A; Ebua Chia, J; Njamnshi, A K; Rota, P A; Waku-Kouomou, D

2018-02-01

Measles is a highly infectious human viral disease caused by measles virus (MeV). An estimated 114 900 measles deaths occurred worldwide in 2014. There are currently eight clades (A-H) comprised 24 MeV genotypes. We sought to characterise MeVs among Central African Republic (CAR) refugees during the 2014 measles epidemic in Cameroon. Samples were collected from children <15 years with suspected measles infections in two refugee camps in the east region of Cameroon. Viral RNA was extracted directly from urine samples. RNA detection of MeV RNA was performed with real-time reverse transcription polymerase chain reaction (PCR) to amplify a 634 bp nucleotide fragment of the N gene. The sequence of the PCR product was obtained to determine the genotype. MeV RNA was detected in 25 out of 30 samples from suspected cases, and among the 25 positive samples, MeV sequences were obtained from 20. The MeV strains characterised were all genotype B3. The MeV strains from genotype B3 found in this outbreak were more similar to those circulating in Northern Cameroon in 2010-2011 than to MeV strains circulating in the CAR in 2011. Surveillance system should be improved to focus on refugees for early detection of and response to outbreaks.

Influence of protein expression system on elicitation of IgE antibody responses: experience with lactoferrin.

PubMed

Almond, Rachael J; Flanagan, Brian F; Kimber, Ian; Dearman, Rebecca J

2012-11-15

With increased interest in genetically modified (GM) crop plants there is an important need to understand the properties that contribute to the ability of such novel proteins to provoke immune and/or allergic responses. One characteristic that may be relevant is glycosylation, particularly as novel expression systems (e.g. bacterial to plant) will impact on the protein glycoprofile. The allergenicity (IgE inducing) and immunogenicity (IgG inducing) properties of wild type native human lactoferrin (NLF) from human milk (hm) and neutrophil granules (n) and a recombinant molecule produced in rice (RLF) have been assessed. These forms of lactoferrin have identical amino acid sequences, but different glycosylation patterns: hmNLF and nNLF have complex glycoprofiles including Lewis (Le)(x) structures, with particularly high levels of Le(x) expressed by nNLF, whereas RLF is simpler and rich in mannose residues. Antibody responses induced in BALB/c strain mice by intraperitoneal exposure to the different forms of lactoferrin were characterised. Immunisation with both forms of NLF stimulated substantial IgG and IgE antibody responses. In contrast, the recombinant molecule was considerably less immunogenic and failed to stimulate detectable IgE, irrespective of endotoxin and iron content. The glycans did not contribute to epitope formation, with equivalent IgE and IgG binding recorded for high titre anti-NLF antisera regardless of whether the immunising NLF or the recombinant molecule were used substrates in the analyses. These data demonstrate that differential glycosylation profiles can have a profound impact on protein allergenicity and immunogenicity, with mannose and Le(x) exhibiting opposing effects. These results have clear relevance for characterising the allergenic hazards of novel proteins in GM crops. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Social influence on associative learning: double dissociation in high-functioning autism, early-stage behavioural variant frontotemporal dementia and Alzheimer's disease.

PubMed

Kéri, Szabolcs

2014-05-01

Most of our learning activity takes place in a social context. I examined how social interactions influence associative learning in neurodegenerative diseases and atypical neurodevelopmental conditions primarily characterised by social cognitive and memory dysfunctions. Participants were individuals with high-functioning autism (HFA, n = 18), early-stage behavioural variant frontotemporal dementia (bvFTD, n = 16) and Alzheimer's disease (AD, n = 20). The leading symptoms in HFA and bvFTD were social and behavioural dysfunctions, whereas AD was characterised by memory deficits. Participants received three versions of a paired associates learning task. In the game with boxes test, objects were hidden in six candy boxes placed in different locations on the computer screen. In the game with faces, each box was labelled by a photo of a person. In the real-life version of the game, participants played with real persons. Individuals with HFA and bvFTD performed well in the computer games, but failed on the task including real persons. In contrast, in patients with early-stage AD, social interactions boosted paired associates learning up to the level of healthy control volunteers. Worse performance in the real life game was associated with less successful recognition of complex emotions and mental states in the Reading the Mind in the Eyes Test. Spatial span did not affect the results. When social cognition is impaired, but memory systems are less compromised (HFA and bvFTD), real-life interactions disrupt associative learning; when disease process impairs memory systems but social cognition is relatively intact (early-stage AD), social interactions have a beneficial effect on learning and memory. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantifying the influence of previously burned areas on suppression effectiveness and avoided exposure: A case study of the Las Conchas Fire

Treesearch

Matthew P. Thompson; Patrick Freeborn; Jon D. Rieck; Dave Calkin; Julie W. Gilbertson-Day; Mark A. Cochrane; Michael S. Hand

2016-01-01

We present a case study of the Las Conchas Fire (2011) to explore the role of previously burned areas (wildfires and prescribed fires) on suppression effectiveness and avoided exposure. Methodological innovations include characterisation of the joint dynamics of fire growth and suppression activities, development of a fire line effectiveness framework, and...

Studying relationships between environment and malaria incidence in Camopi (French Guiana) through the objective selection of buffer-based landscape characterisations

PubMed Central

2011-01-01

Background Malaria remains a major health problem in French Guiana, with a mean of 3800 cases each year. A previous study in Camopi, an Amerindian village on the Oyapock River, highlighted the major contribution of environmental features to the incidence of malaria attacks. We propose a method for the objective selection of the best multivariate peridomestic landscape characterisation that maximises the chances of identifying relationships between environmental features and malaria incidence, statistically significant and meaningful from an epidemiological point of view. Methods A land-cover map, the hydrological network and the geolocalised inhabited houses were used to characterise the peridomestic landscape in eleven discoid buffers with radii of 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 metres. Buffer-based landscape characterisations were first compared in terms of their capacity to discriminate between sites within the geographic space and of their effective multidimensionality in variable space. The Akaike information criterion (AIC) was then used to select the landscape model best explaining the incidences of P. vivax and P. falciparum malaria. Finally, we calculated Pearson correlation coefficients for the relationships between environmental variables and malaria incidence, by species, for the more relevant buffers. Results The optimal buffers for environmental characterisation had radii of 100 m around houses for P. vivax and 400 m around houses for P. falciparum. The incidence of P. falciparum malaria seemed to be more strongly linked to environmental features than that of P. vivax malaria, within these buffers. The incidence of P. falciparum malaria in children was strongly correlated with proportions of bare soil (r = -0.69), land under high vegetation (r = 0.68) and primary forest (r = 0.54), landscape division (r = 0.48) and the number of inhabited houses (r = -0.60). The incidence of P. vivax malaria was associated only with landscape division (r = 0.49). Conclusions The proposed methodology provides a simple and general framework for objective characterisation of the landscape to account for field observations. The use of this method enabled us to identify different optimal observation horizons around houses, depending on the Plasmodium species considered, and to demonstrate significant correlations between environmental features and the incidence of malaria. PMID:22151738

Studying relationships between environment and malaria incidence in Camopi (French Guiana) through the objective selection of buffer-based landscape characterisations.

PubMed

Stefani, Aurélia; Roux, Emmanuel; Fotsing, Jean-Marie; Carme, Bernard

2011-12-13

Malaria remains a major health problem in French Guiana, with a mean of 3800 cases each year. A previous study in Camopi, an Amerindian village on the Oyapock River, highlighted the major contribution of environmental features to the incidence of malaria attacks. We propose a method for the objective selection of the best multivariate peridomestic landscape characterisation that maximises the chances of identifying relationships between environmental features and malaria incidence, statistically significant and meaningful from an epidemiological point of view. A land-cover map, the hydrological network and the geolocalised inhabited houses were used to characterise the peridomestic landscape in eleven discoid buffers with radii of 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 metres. Buffer-based landscape characterisations were first compared in terms of their capacity to discriminate between sites within the geographic space and of their effective multidimensionality in variable space. The Akaike information criterion (AIC) was then used to select the landscape model best explaining the incidences of P. vivax and P. falciparum malaria. Finally, we calculated Pearson correlation coefficients for the relationships between environmental variables and malaria incidence, by species, for the more relevant buffers. The optimal buffers for environmental characterisation had radii of 100 m around houses for P. vivax and 400 m around houses for P. falciparum. The incidence of P. falciparum malaria seemed to be more strongly linked to environmental features than that of P. vivax malaria, within these buffers. The incidence of P. falciparum malaria in children was strongly correlated with proportions of bare soil (r = -0.69), land under high vegetation (r = 0.68) and primary forest (r = 0.54), landscape division (r = 0.48) and the number of inhabited houses (r = -0.60). The incidence of P. vivax malaria was associated only with landscape division (r = 0.49). The proposed methodology provides a simple and general framework for objective characterisation of the landscape to account for field observations. The use of this method enabled us to identify different optimal observation horizons around houses, depending on the Plasmodium species considered, and to demonstrate significant correlations between environmental features and the incidence of malaria. © 2011 Stefani et al; licensee BioMed Central Ltd.

Potential of Sr isotopic analysis in ceramic provenance studies: Characterisation of Chinese stonewares

NASA Astrophysics Data System (ADS)

Li, Bao-Ping; Zhao, Jian-Xin; Greig, Alan; Collerson, Kenneth D.; Zhuo, Zhen-Xi; Feng, Yue-Xin

2005-11-01

We compare the trace element and Sr isotopic compositions of stoneware bodies made in Yaozhou and Jizhou to characterise these Chinese archaeological ceramics and examine the potential of Sr isotopes in provenance studies. Element concentrations determined by ICP-MS achieve distinct characterisation for Jizhou samples due to their restricted variation, yet had limited success with Yaozhou wares because of their large variability. In contrast, 87Sr/86Sr ratios in Yaozhou samples have a very small variation and are all significantly lower than those of Jizhou samples, which show a large variation and cannot be well characterised with Sr isotopes. Geochemical interpretation reveals that 87Sr/86Sr ratios will have greater potential to characterise ceramics made of low Rb/Sr materials such as kaolin clay, yet will show larger variations in ceramics made of high Rb/Sr materials such as porcelain stone.

The Effects of Different Drawing Materials on Children's Drawings of Positive and Negative Human Figures

ERIC Educational Resources Information Center

Burkitt, Esther; Barrett, Martyn

2011-01-01

Children tend to use certain drawing strategies differentially when asked to draw topics with positive and negative emotional characterisations. These effects have however only been established when children are asked to use standard drawing materials. The present study was designed to investigate whether the above pattern of children's response…

Detection and characterisation of Complement protein activity in bovine milk by bactericidal sequestration assay.

PubMed

Maye, Susan; Stanton, Catherine; Fitzgerald, Gerald F; Kelly, Philip M

2015-08-01

While the Complement protein system in human milk is well characterised, there is little information on its presence and activity in bovine milk. Complement forms part of the innate immune system, hence the importance of its contribution during milk ingestion to the overall defences of the neonate. A bactericidal sequestration assay, featuring a Complement sensitive strain, Escherichia coli 0111, originally used to characterise Complement activity in human milk was successfully applied to freshly drawn bovine milk samples, thus, providing an opportunity to compare Complement activities in both human and bovine milks. Although not identical in response, the levels of Complement activity in bovine milk were found to be closely comparable with that of human milk. Differential counts of Esch. coli 0111 after 2 h incubation were 6.20 and 6.06 log CFU/ml, for raw bovine and human milks, respectively - the lower value representing a stronger Complement response. Exposing bovine milk to a range of thermal treatments e.g. 42, 45, 65, 72, 85 or 95 °C for 10 min, progressively inhibited Complement activity by increasing temperature, thus confirming the heat labile nature of this immune protein system. Low level Complement activity was found, however, in 65 and 72 °C heat treated samples and in retailed pasteurised milk which highlights the outer limit to which high temperature, short time (HTST) industrial thermal processes should be applied if retention of activity is a priority. Concentration of Complement in the fat phase was evident following cream separation, and this was also reflected in the further loss of activity recorded in low fat variants of retailed pasteurised milk. Laboratory-based churning of the cream during simulated buttermaking generated an aqueous (buttermilk) phase with higher levels of Complement activity than the fat phase, thus pointing to a likely association with the milk fat globule membrane (MFGM) layer.

Investigating the internal structure of galaxies and clusters through strong gravitational lensing

NASA Astrophysics Data System (ADS)

Jigish Gandhi, Pratik; Grillo, Claudio; Bonamigo, Mario

2018-01-01

Gravitational lensing studies have radically improved our understanding of the internal structure of galaxies and cluster-scale systems. In particular, the combination of strong lensing and stellar dynamics or stellar population synthesis models have made it possible to characterize numerous fundamental properties of the galaxies as well as dark matter halos and subhalos with unprecedented robustness and accuracy. Here we demonstrate the usefulness and accuracy of strong lensing as a probe for characterising the properties of cluster members as well as dark matter halos, to show that such characterisation carried out via lensing analyses alone is as viable as those carried out through a combination of spectroscopy and lensing analyses.Our study uses focuses on the early-type galaxy cluster MACS J1149.5+2223 at redshift 0.54 in the Hubble Frontier Fields (HFF) program, where the first magnified and spatially resolved multiple images of supernova (SN) “Refsdal” and its late-type host galaxy at redshift 1.489 were detected. The Refsdal system is unique in being the first ever multiply-imaged supernova, with it’s first four images appearing in an Einstein Cross configuration around one of the cluster members in 2015. In our lensing analyses we use HST data of the multiply-imaged SN Refsdal to constrain the dynamical masses, velocity dispersions, and virial radii of individual galaxies and dark matter halos in the MACS J1149.5+2223 cluster. For our lensing models we select a sample of 300 cluster members within approximately 500 kpc from the BCG, and a set of reliable multiple images associated with 18 distinct knots in the SN host spiral galaxy, as well as multiple images of the supernova itself. Our results provide accurate measurements of the masses, velocity dispersions, and radii of the cluster’s dark matter halo as well as three chosen members galaxies, in strong agreement with those obtained by Grillo et al 2015, demonstrating the usefulness of strong lensing in characterising the properties of cluster-scale systems.

Characterising the perceived value of mathematics educational apps in preservice teachers

NASA Astrophysics Data System (ADS)

Handal, Boris; Campbell, Chris; Cavanagh, Michael; Petocz, Peter

2016-03-01

This study validated the semantic items of three related scales aimed at characterising the perceived worth of mathematics-education-related mobile applications (apps). The technological pedagogical content knowledge (TPACK) model was used as the conceptual framework for the analysis. Three hundred and seventy-three preservice students studying primary school education from two public and one private Australian universities participated in the study. The respondents examined three different apps using a purposively designed instrument in regard to either their explorative, productive or instructive instructional role. While construct validity could not be established due to a broad range of variability in responses implying a high degree of subjectivity in respondents' judgments, the qualitative analysis was effective in establishing content validity.

3D imaging of cells in scaffolds: direct labelling for micro CT.

PubMed

Shepherd, David V; Shepherd, Jennifer H; Best, Serena M; Cameron, Ruth E

2018-06-12

The development of in-vitro techniques to characterise the behaviour of cells in biomedical scaffolds is a rapidly developing field. However, until now it has not been possible to visualise, directly in 3D, the extent of cell migration using a desktop X-ray microCT. This paper describes a new technique based on cell labelling with a radio opacifier (barium sulphate), which permits cell tracking without the need for destructive sample preparation. The ability to track cells is highlighted via a comparison of cell migration through demonstrator lyophilised collagen scaffolds with contrasting pore size and interconnectivity. The results demonstrate the ease with which the technique can be used to characterise the effects of scaffold architecture on cell infiltration.

The Tanzanian trauma patients' prehospital experience: a qualitative interview-based study.

PubMed

Kuzma, Kristin; Lim, Andrew George; Kepha, Bernard; Nalitolela, Neema Evelyne; Reynolds, Teri A

2015-04-27

We sought to characterise the prehospital experience of Tanzanian trauma patients, and identify barriers and facilitators to implement community-based emergency medical systems (EMS). Our study was conducted in the emergency department of an urban national referral hospital in Tanzania. A convenience sample of 34 adult trauma patients, or surrogate family members, presenting or referred to an urban referral emergency department in Tanzania for treatment of injury, participated in the study. Participation in semistructured, iteratively developed interviews until saturation of responses was reached. A grounded theory-based approach to qualitative analysis was used to identify recurrent themes. We characterised numerous deficiencies within the existing clinic-to-hospital referral network, including missed/delayed diagnoses, limited management capabilities at pre-referral facilities and interfacility transfer delays. Potential barriers to EMS implementation include patient financial limitations and lack of insurance, limited public infrastructure and resources, and the credibility of potential first aid responders. Potential facilitators of EMS include communities' tendency to pool resources, individuals' trust of other community members to be first aid responders, and faith in community leaders to organise EMS response. Participants expressed a strong desire to learn first aid. The composite themes generated by the data suggest that there are myriad structural, financial, institutional and cultural barriers to the implementation of a formal prehospital system. However, our analysis also revealed potential facilitators to a first-responder system that takes advantage of close-knit local communities and the trust of recognised leaders in society. The results suggest favourable acceptability for community-based response by trained lay people. There is significant opportunity for care improvements with short trainings and low-cost supply planning. Further research looking at the effects of delay on outcomes in this population is needed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Slugtests in fractured aquifers - advantages and caveats

NASA Astrophysics Data System (ADS)

Sauter, Martin

2017-04-01

The hydraulic characterisation of fractured aquifers is a challenge due to the large contrast between conductive fractures and a relative low conductive rock matrix. Depending on the type of problem, spanning from water resources issues at catchment scale to contaminant transport at local, borehole scale, different methodological approaches are required. The employment of slugtests as a characterisation method has a major advantage above classical pumping tests since they provide information also for the lower end of the permeability spectrum and are less logistically demanding. However, the volume of investigation of slugtests is generally small and limited to the immediate borehole area. The application of slug tests to fractured systems was investigated by Barker and Black (1983); Dougherty and Babu (1984) and Karasaki et al. (1988). Barker and Black (1983) pointed out the non-uniqueness of type curves with re¬spect to determining reservoir parameters, apart from hydraulic conductivity and sto¬rage coefficients. The unknowns in¬clude fissure densities, apertures and the hy¬draulic parameters of the rock matrix. They found that the Cooper method syste¬matically overestimates aquifer transmis-sivities by a factor of up to three. This figure however applies to a fairly homogeneously fissured aquifer such as the English Chalk. Dougherty and Babu (1984) examined in detail the effects of partial penetration, dif¬ferent skin factors and mass exchange coef-ficients in a double porosity system. They did however not present any parameter estimation solu¬tion. Karasaki et al. (1988) developed type curves for heterogeneous aquifer systems and came to the conclusion that "slug tests suffer problems of non-uniqueness to a greater ex¬tent than other well tests". In this paper, this aspect of non-uniqueness is addressed in detail, based on slugtest data in a fractured and karstified aquifer from the Swabian Alb in the SW of Germany, explanations and models of interpretation are provided and assessed with respect to their relative importance.

Nanoparticle-mediated siRNA delivery assessed in a 3D co-culture model simulating prostate cancer bone metastasis.

PubMed

Fitzgerald, Kathleen A; Guo, Jianfeng; Raftery, Rosanne M; Castaño, Irene Mencía; Curtin, Caroline M; Gooding, Matt; Darcy, Raphael; O' Brien, Fergal J; O' Driscoll, Caitriona M

2016-09-25

siRNA has emerged as a potential therapeutic for the treatment of prostate cancer but effective delivery remains a major barrier to its clinical application. This study aimed to develop and characterise a 3D in vitro co-culture model to simulate prostate cancer bone metastasis and to assess the ability of the model to investigate nanoparticle-mediated siRNA delivery and gene knockdown. PC3 or LNCaP prostate cancer cells were co-cultured with hFOB 1.19 osteoblast cells in 2D on plastic tissue culture plates and in 3D on collagen scaffolds mimicking the bone microenvironment. To characterise the co-culture model, cell proliferation, enzyme secretion and the utility of two different gene delivery vectors to mediate siRNA uptake and gene knockdown were assessed. Cell proliferation was reduced by∼50% by day 7 in the co-culture system relative to monoculture (PC3 and LNCaP co-cultures, in 2D and 3D) and an enhanced level of MMP9 (a marker of bone metastasis) was secreted into the media (1.2-4-fold increase depending on the co-culture system). A cationic cyclodextrin gene delivery vector proved significantly less toxic in the co-culture system relative to the commercially available vector Lipofectamine 2000(®). In addition, knockdown of both the GAPDH gene (minimum 15%) and RelA subunit of the NF-κB transcription factor (minimum 20%) was achieved in 2D and 3D cell co-cultures. Results indicate that the prostate cancer-osteoblast in vitro co-culture model was more physiologically relevant vs the monoculture. This model has the potential to help improve the design and efficacy of gene delivery formulations, to more accurately predict in vivo performance and, therefore, to reduce the risk of product failure in late-stage clinical development. Copyright © 2016 Elsevier B.V. All rights reserved.

The embodied embedded character of system 1 processing.

PubMed

Bellini-Leite, Samuel de Castro

2013-01-01

In the last thirty years, a relatively large group of cognitive scientists have begun characterising the mind in terms of two distinct, relatively autonomous systems. To account for paradoxes in empirical results of studies mainly on reasoning, Dual Process Theories were developed. Such Dual Process Theories generally agree that System 1 is rapid, automatic, parallel, and heuristic-based and System 2 is slow, capacity-demanding, sequential, and related to consciousness. While System 2 can still be decently understood from a traditional cognitivist approach, I will argue that it is essential for System 1 processing to be comprehended in an Embodied Embedded approach to Cognition.

The Embodied Embedded Character of System 1 Processing

PubMed Central

Bellini-Leite, Samuel de Castro

2013-01-01

In the last thirty years, a relatively large group of cognitive scientists have begun characterising the mind in terms of two distinct, relatively autonomous systems. To account for paradoxes in empirical results of studies mainly on reasoning, Dual Process Theories were developed. Such Dual Process Theories generally agree that System 1 is rapid, automatic, parallel, and heuristic-based and System 2 is slow, capacity-demanding, sequential, and related to consciousness. While System 2 can still be decently understood from a traditional cognitivist approach, I will argue that it is essential for System 1 processing to be comprehended in an Embodied Embedded approach to Cognition. PMID:23678245

ADM1-based methodology for the characterisation of the influent sludge in anaerobic reactors.

PubMed

Huete, E; de Gracia, M; Ayesa, E; Garcia-Heras, J L

2006-01-01

This paper presents a systematic methodology to characterise the influent sludge in terms of the ADM1 components from the experimental measurements traditionally used in wastewater engineering. For this purpose, a complete characterisation of the model components in their elemental mass fractions and charge has been used, making a rigorous mass balance for all the process transformations and enabling the future connection with other unit-process models. It also makes possible the application of mathematical algorithms for the optimal characterisation of several components poorly defined in the ADM1 report. Additionally, decay and disintegration have been necessarily uncoupled so that the decay proceeds directly to hydrolysis instead of producing intermediate composites. The proposed methodology has been applied to the particular experimental work of a pilot-scale CSTR treating real sewage sludge, a mixture of primary and secondary sludge. The results obtained have shown a good characterisation of the influent reflected in good model predictions. However, its limitations for an appropriate prediction of alkalinity and carbon percentages in biogas suggest the convenience of including the elemental characterisation of the process in terms of carbon in the analytical program.

Effect of image scaling and segmentation in digital rock characterisation

NASA Astrophysics Data System (ADS)

Jones, B. D.; Feng, Y. T.

2016-04-01

Digital material characterisation from microstructural geometry is an emerging field in computer simulation. For permeability characterisation, a variety of studies exist where the lattice Boltzmann method (LBM) has been used in conjunction with computed tomography (CT) imaging to simulate fluid flow through microscopic rock pores. While these previous works show that the technique is applicable, the use of binary image segmentation and the bounceback boundary condition results in a loss of grain surface definition when the modelled geometry is compared to the original CT image. We apply the immersed moving boundary (IMB) condition of Noble and Torczynski as a partial bounceback boundary condition which may be used to better represent the geometric definition provided by a CT image. The IMB condition is validated against published work on idealised porous geometries in both 2D and 3D. Following this, greyscale image segmentation is applied to a CT image of Diemelstadt sandstone. By varying the mapping of CT voxel densities to lattice sites, it is shown that binary image segmentation may underestimate the true permeability of the sample. A CUDA-C-based code, LBM-C, was developed specifically for this work and leverages GPU hardware in order to carry out computations.

Characterisation of transition state structures for protein folding using 'high', 'medium' and 'low' {Phi}-values.

PubMed

Geierhaas, Christian D; Salvatella, Xavier; Clarke, Jane; Vendruscolo, Michele

2008-03-01

It has been suggested that Phi-values, which allow structural information about transition states (TSs) for protein folding to be obtained, are most reliably interpreted when divided into three classes (high, medium and low). High Phi-values indicate almost completely folded regions in the TS, intermediate Phi-values regions with a detectable amount of structure and low Phi-values indicate mostly unstructured regions. To explore the extent to which this classification can be used to characterise in detail the structure of TSs for protein folding, we used Phi-values divided into these classes as restraints in molecular dynamics simulations. This type of procedure is related to that used in NMR spectroscopy to define the structure of native proteins from the measurement of inter-proton distances derived from nuclear Overhauser effects. We illustrate this approach by determining the TS ensembles of five proteins and by showing that the results are similar to those obtained by using as restraints the actual numerical Phi-values measured experimentally. Our results indicate that the simultaneous consideration of a set of low-resolution Phi-values can provide sufficient information for characterising the architecture of a TS for folding of a protein.

Characterisation of transition state structures for protein folding using ‘high’, ‘medium’ and ‘low’ Φ-values

PubMed Central

Geierhaas, Christian D.; Salvatella, Xavier; Clarke, Jane; Vendruscolo, Michele

2008-01-01

It has been suggested that Φ-values, which allow structural information about transition states (TSs) for protein folding to be obtained, are most reliably interpreted when divided into three classes (high, medium and low). High Φ-values indicate almost completely folded regions in the TS, intermediate Φ-values regions with a detectable amount of structure and low Φ-values indicate mostly unstructured regions. To explore the extent to which this classification can be used to characterise in detail the structure of TSs for protein folding, we used Φ-values divided into these classes as restraints in molecular dynamics simulations. This type of procedure is related to that used in NMR spectroscopy to define the structure of native proteins from the measurement of inter-proton distances derived from nuclear Overhauser effects. We illustrate this approach by determining the TS ensembles of five proteins and by showing that the results are similar to those obtained by using as restraints the actual numerical Φ-values measured experimentally. Our results indicate that the simultaneous consideration of a set of low-resolution Φ-values can provide sufficient information for characterising the architecture of a TS for folding of a protein. PMID:18299294

Dendrimers

NASA Astrophysics Data System (ADS)

Bryant, L. Henry; Bulte, Jeff W. M.

Dendrimers have received an enormous amount of attention in the last ten years and several recent review articles have appeared in the literature that address their potential applications [1-3]. Stoddart et al [1] have stated that: "We are now approaching a time when the study of dendriniers bec omes inextricably linked with many other fields, leaving the comprehensive reviewer of the subject a near-impossible task to fulfil". On that note, this review provides a brief introduction to the chemical principles of dendrimers by highlighting main synthetic strategies and methods for characterisation. p]Dendrimers containing heteroatoms will not be reviewed per se since these have recently been reviewed [4]. The major thrust of this review is the potential applications of dendrimers in such areas as boron neutron capture therapy, as contrast agents in magnetic resonance imaging, as vaccines, as cellular transfection agents and as bioconjugate dendrimers, i.e., in-vitro immunoassays for antigens. The outline used in this review proved to be effective in classifying most published papers about dendrimers, but it must be kept in mind that some articles not only transcended two different classifications, such as synthesis and characterisation, but several classifications such as synthesis, characterisation and at least one potential application covered in this review.

Seeking a fingerprint: analysis of point processes in actigraphy recording

NASA Astrophysics Data System (ADS)

Gudowska-Nowak, Ewa; Ochab, Jeremi K.; Oleś, Katarzyna; Beldzik, Ewa; Chialvo, Dante R.; Domagalik, Aleksandra; Fąfrowicz, Magdalena; Marek, Tadeusz; Nowak, Maciej A.; Ogińska, Halszka; Szwed, Jerzy; Tyburczyk, Jacek

2016-05-01

Motor activity of humans displays complex temporal fluctuations which can be characterised by scale-invariant statistics, thus demonstrating that structure and fluctuations of such kinetics remain similar over a broad range of time scales. Previous studies on humans regularly deprived of sleep or suffering from sleep disorders predicted a change in the invariant scale parameters with respect to those for healthy subjects. In this study we investigate the signal patterns from actigraphy recordings by means of characteristic measures of fractional point processes. We analyse spontaneous locomotor activity of healthy individuals recorded during a week of regular sleep and a week of chronic partial sleep deprivation. Behavioural symptoms of lack of sleep can be evaluated by analysing statistics of duration times during active and resting states, and alteration of behavioural organisation can be assessed by analysis of power laws detected in the event count distribution, distribution of waiting times between consecutive movements and detrended fluctuation analysis of recorded time series. We claim that among different measures characterising complexity of the actigraphy recordings and their variations implied by chronic sleep distress, the exponents characterising slopes of survival functions in resting states are the most effective biomarkers distinguishing between healthy and sleep-deprived groups.

A method to reduce patient's eye lens dose in neuro-interventional radiology procedures

NASA Astrophysics Data System (ADS)

Safari, M. J.; Wong, J. H. D.; Kadir, K. A. A.; Sani, F. M.; Ng, K. H.

2016-08-01

Complex and prolonged neuro-interventional radiology procedures using the biplane angiography system increase the patient's risk of radiation-induced cataract. Physical collimation is the most effective way of reducing the radiation dose to the patient's eye lens, but in instances where collimation is not possible, an attenuator may be useful in protecting the eyes. In this study, an eye lens protector was designed and fabricated to reduce the radiation dose to the patients' eye lens during neuro-interventional procedures. The eye protector was characterised before being tested on its effectiveness in a simulated aneurysm procedure on an anthropomorphic phantom. Effects on the automatic dose rate control (ADRC) and image quality are also evaluated. The eye protector reduced the radiation dose by up to 62.1% at the eye lens. The eye protector is faintly visible in the fluoroscopy images and increased the tube current by a maximum of 3.7%. It is completely invisible in the acquisition mode and does not interfere with the clinical procedure. The eye protector placed within the radiation field of view was able to reduce the radiation dose to the eye lens by direct radiation beam of the lateral x-ray tube with minimal effect on the ADRC system.

Characterising Wildlife Trade Market Supply-Demand Dynamics

PubMed Central

Rowcliffe, M.; Cowlishaw, G.; Alexander, J. S.; Ntiamoa-Baidu, Y.; Brenya, A.; Milner-Gulland, E. J.

2016-01-01

The trade in wildlife products can represent an important source of income for poor people, but also threaten wildlife locally, regionally and internationally. Bushmeat provides livelihoods for hunters, traders and sellers, protein to rural and urban consumers, and has depleted the populations of many tropical forest species. Management interventions can be targeted towards the consumers or suppliers of wildlife products. There has been a general assumption in the bushmeat literature that the urban trade is driven by consumer demand with hunters simply fulfilling this demand. Using the urban bushmeat trade in the city of Kumasi, Ghana, as a case study, we use a range of datasets to explore the processes driving the urban bushmeat trade. We characterise the nature of supply and demand by explicitly considering three market attributes: resource condition, hunter behaviour, and consumer behaviour. Our results suggest that bushmeat resources around Kumasi are becoming increasingly depleted and are unable to meet demand, that hunters move in and out of the trade independently of price signals generated by the market, and that, for the Kumasi bushmeat system, consumption levels are driven not by consumer choice but by shortfalls in supply and consequent price responses. Together, these results indicate that supply-side processes dominate the urban bushmeat trade in Kumasi. This suggests that future management interventions should focus on changing hunter behaviour, although complementary interventions targeting consumer demand are also likely to be necessary in the long term. Our approach represents a structured and repeatable method to assessing market dynamics in information-poor systems. The findings serve as a caution against assuming that wildlife markets are demand driven, and highlight the value of characterising market dynamics to inform appropriate management. PMID:27632169

Pollen and stigma size changes during the transition from tristyly to distyly in Oxalis alpina (Oxalidaceae).

PubMed

Baena-Díaz, F; Fornoni, J; Sosenski, P; Weller, S G; Domínguez, C A

2017-11-01

Pollen and stigma size have the potential to influence male fitness of hermaphroditic plants, particularly in species presenting floral polymorphisms characterised by marked differences in these traits among floral morphs. In this study, we take advantage of the evolutionary transition from tristyly to distyly experienced by Oxalis alpina (Oxalidaceae), and examined whether modifications in the ancillary traits (pollen and stigma size) respond to allometric changes in other floral traits. Also, we tested whether these modifications are in accordance with what would be expected under the hypothesis that novel competitive scenarios (as in distylous-derived reproductive system) exert morph- and whorl-specific selective pressures to match the available stigmas. We measure pollen and stigma size in five populations of O. alpina representing the tristyly-distyly transition. A general reduction in pollen and stigma size occurred along the tristyly-distyly transition, and pollen size from the two anther levels within each morph converged to a similar size that was characterised by whorl-specific changes (increases or decreases) in pollen size of different anthers in each floral type. Overall, results from this study show that the evolution of distyly in this species is characterised not only by changes in sexual organ position and flower size, but also by morph-specific changes in pollen and stigma size. This evidence supports the importance of selection on pollen and stigma size, which increase fitness of remaining morphs following the evolution of distyly, and raises questions to explore on the functional value of pollen size in heterostylous systems under pollen competition. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

Relationships between electron transport system (ETS) activity and particulate organic matter features in three areas of the Ross Sea (Antarctica)

NASA Astrophysics Data System (ADS)

Misic, C.; Covazzi Harriague, A.; Giglio, F.; La Ferla, R.; Rappazzo, A. C.; Azzaro, M.

2017-11-01

Electron transport system activity (ETSa) and particulate organic matter (POM) concentrations and composition were measured in three areas of the continental shelf of the Ross Sea during summer 2014, in the framework of the Ross Sea Mesoscale Experiment (ROME) project. We aimed at testing whether in the epipelagic layer (0-200 m) ETS showed different activity depending on the geographical position and on the different hydrological structures that characterised each area, as eddy and fronts, and whether the ETSa of the microplanktonic fraction depended on POM quantitative and qualitative features. ETSa showed differences between the three areas, but within each of them the different hydrological conditions did not influence significantly the respiration activity. ETSa displayed significant correlations with POM, especially in the offshore areas characterised by residual ice influence and by a mesoscale eddy structure. In these zones ETSa was enhanced by good trophic value of POM, i.e. showing dominance of proteins and PON over structural carbohydrates and POC, respectively. The role of the phytoplanktonic fraction in ETSa was higher in the eddy-influenced area, that showed significantly higher chlorophyll-a concentrations. On the other hand, in the area placed coastward, the relationships between ETSa and POM changed. High ETSa were found in the subsurface layer and down to 100 m depth and were related to more refractory POM, whose utilization would require higher energy. Different ETSa-POM relationships were consistent with the anomalous phytoplanktonic bloom detected in the coastward area, characterised by Phaeocystis. Thus, the anomalies of the primary producers are reflected by changes in POM respiration and potential C utilization.

Characterising Wildlife Trade Market Supply-Demand Dynamics.

PubMed

McNamara, J; Rowcliffe, M; Cowlishaw, G; Alexander, J S; Ntiamoa-Baidu, Y; Brenya, A; Milner-Gulland, E J

2016-01-01

The trade in wildlife products can represent an important source of income for poor people, but also threaten wildlife locally, regionally and internationally. Bushmeat provides livelihoods for hunters, traders and sellers, protein to rural and urban consumers, and has depleted the populations of many tropical forest species. Management interventions can be targeted towards the consumers or suppliers of wildlife products. There has been a general assumption in the bushmeat literature that the urban trade is driven by consumer demand with hunters simply fulfilling this demand. Using the urban bushmeat trade in the city of Kumasi, Ghana, as a case study, we use a range of datasets to explore the processes driving the urban bushmeat trade. We characterise the nature of supply and demand by explicitly considering three market attributes: resource condition, hunter behaviour, and consumer behaviour. Our results suggest that bushmeat resources around Kumasi are becoming increasingly depleted and are unable to meet demand, that hunters move in and out of the trade independently of price signals generated by the market, and that, for the Kumasi bushmeat system, consumption levels are driven not by consumer choice but by shortfalls in supply and consequent price responses. Together, these results indicate that supply-side processes dominate the urban bushmeat trade in Kumasi. This suggests that future management interventions should focus on changing hunter behaviour, although complementary interventions targeting consumer demand are also likely to be necessary in the long term. Our approach represents a structured and repeatable method to assessing market dynamics in information-poor systems. The findings serve as a caution against assuming that wildlife markets are demand driven, and highlight the value of characterising market dynamics to inform appropriate management.

Geochemical characterisation of gases along the dead sea rift: Evidences of mantle-co2 degassing

NASA Astrophysics Data System (ADS)

Inguaggiato, C.; Censi, P.; D'Alessandro, W.; Zuddas, P.

2016-06-01

The Dead Sea Transform (DST) fault system, where a lateral displacement between the African and Arabian plates occurs, is characterised by anomalous heat flux in the Israeli area close to the border with Syria and Jordan. The concentration of He and CO2, and isotopic composition of He and total dissolved inorganic carbon were studied in cold and thermal waters collected along the DST, in order to investigate the source of volatiles and their relationship with the tectonic framework of the DST. The waters with higher temperature (up to 57.2 °C) are characterised by higher amounts of CO2 and helium (up to 55.72 and 1.91 ∗ 10- 2 cc l- 1, respectively). Helium isotopic data (R/Ra from 0.11 to 2.14) and 4He/20Ne ratios (0.41-106.86) show the presence of deep-deriving fluids consisting of a variable mixture of mantle and crust end-members, with the former reaching up to 35%. Carbon isotope signature of total dissolved carbon from hot waters falls within the range of magmatic values, suggesting the delivery of deep-seated CO2. The geographical distribution of helium isotopic data and isotopic carbon (CO2) values coupled with (CO2/3He ratios) indicate a larger contribution of mantle-derived fluids affecting the northern part of the investigated area, where the waters reach the highest temperature. These evidences suggest the occurrence of a favourable tectonic framework, including a Moho discontinuity up-rise and/or the presence of a deep fault system coupled with the recent magmatic activity recognised in the northern part of Israel.

Partial characterisation of digestive proteases of the Mayan cichlid Cichlasoma urophthalmus.

PubMed

Cuenca-Soria, C A; Álvarez-González, C A; Ortiz-Galindo, J L; Nolasco-Soria, H; Tovar-Ramírez, D; Guerrero-Zárate, R; Castillo-Domínguez, A; Perera-García, M A; Hernández-Gómez, R; Gisbert, E

2014-06-01

The characterisation of digestive proteases in native freshwater fish such as the Mayan cichlid Cichlasoma urophthalmus provides scientific elements that may be used to design balanced feed that matches with the digestive capacity of the fish. The purpose of this study was to characterise the digestive proteases, including the effect of the pH and the temperature on enzyme activity and stability, as well as the effect of inhibitors using multienzymatic extracts of the stomach and intestine of C. urophthalmus juveniles. Results showed that the optimum activities of the acid and alkaline proteases occurred at pH values of 3 and 9, respectively, whereas their optimum temperatures were 55 and 65 °C, respectively. The acid proteases were most stable at pH values of 2–3 and at temperatures of 35–45 °C, whereas the alkaline proteases were most stable at pH values of 6–9 and at 25–55 °C. The inhibition assays recorded a residual activity of 4% with pepstatin A for the acid proteases. The inhibition of the alkaline proteases was greater than 80% with TPCK, TLCK, EDTA and ovalbumin, and of 60 and 43.8% with PMSF and SBT1, respectively. The results obtained in this study make it possible to state that C. urophthalmus has a sufficiently complete digestive enzyme machinery to degrade food items characteristic of an omnivorous fish species, although specimens showed a tendency to carnivory.

SBSS Demonstrator: A design for efficient demonstration of Space-based Space Surveillance end-to-end capabilities

NASA Astrophysics Data System (ADS)

Utzmann, Jens; Flohrer, Tim; Schildknecht, Thomas; Wagner, Axel; Silha, Jiri; Willemsen, Philip; Teston, Frederic

This paper presents the capabilities of a Space-Based Space Surveillance (SBSS) demonstration mission for Space Surveillance and Tracking (SST) based on a micro-satellite platform. The results have been produced in the frame of ESA’s "Assessment Study for Space Based Space Surveillance Demonstration Mission" performed by the Airbus Defence and Space consortium. Space Surveillance and Tracking is part of Space Situational Awareness (SSA) and covers the detection, tracking and cataloguing of space debris and satellites. Derived SST services comprise a catalogue of these man-made objects, collision warning, detection and characterisation of in-orbit fragmentations, sub-catalogue debris characterisation, etc. The assessment of SBSS in a SST system architecture has shown that both an operational SBSS and also already a well-designed space-based demonstrator can provide substantial performance in terms of surveillance and tracking of beyond-LEO objects. Especially the early deployment of a demonstrator, possible by using standard equipment, could boost initial operating capability and create a self-maintained object catalogue. Furthermore, unique statistical information about small-size LEO debris (mm size) can be collected in-situ. Unlike classical technology demonstration missions, the primary goal is the demonstration and optimisation of the functional elements in a complex end-to-end chain (mission planning, observation strategies, data acquisition, processing and fusion, etc.) until the final products can be offered to the users. Also past and current missions by the US (SBV, SBSS) and Canada (Sapphire, NEOSSat) underline the advantages of space-based space surveillance. The presented SBSS system concept takes the ESA SST System Requirements (derived within the ESA SSA Preparatory Program) into account and aims at fulfilling SST core requirements in a stand-alone manner. Additionally, requirments for detection and characterisation of small-sized LEO debris are considered. The evaluation of the concept has shown that an according solution can be implemented with low technological effort and risk. The paper presents details of the system concept, candidate micro-satellite platforms, the observation strategy and the results of performance simulations for space debris coverage and cataloguing accuracy.

Characterizing ocean gyres formation within a bay using vorticity and HF radar measurements

NASA Astrophysics Data System (ADS)

Ragnoli, E.; Donncha, F. O.; Hartnett, M.

2012-04-01

In situations in which wind forcing plays a dominant role in surface currents it becomes important to understand its correlation with parameters that can be used to characterise circulation patterns within a bay. These datasets can then be used in the detection and characterisation of ocean gyres. A network of high frequency radars (NUIG CODAR) is deployed within Galway Bay, on the West Coast of Ireland as a backbone system within an integrated coastal ocean observation system. This system provides real-time synoptic measurements of both ocean surface currents and surface waves across the entire bay. In this work, vorticity is identified as a defining quantity for the characterisation of circulating flow patterns (in particular for the detection of ocean gyres) and it is directly calculated from the measured velocity vectors of NUIG CODAR. A correlation study with wind and tide measurements is then undertaken in order to investigate the dependencies between vorticity and those parameters. A comprehensive NUIG CODAR, weather station and tide gauge monitoring program was conducted over a 30 days period and the data collected analysed for the correlation with the computed vorticity. Tidal information from the FES2004 Global tidal atlas defined surface elevations at the open sea boundaries in the west and in the south. Data from a tide gauge deployed within the bay, which provided real-time tidal data at 6 minute intervals, was used to fine-tune model elevations. A weather station located at National University of Ireland, Galway provided measured wind data for the model. The NUIG CODAR coastal observation system detects strong, non-persistent, gyre formation within Galway Bay. During periods of relatively large tidal ranges (order 4m) and light wind conditions well defined, cyclonic circulation is developed within the bay. The correlation analysis shows that the gyres tend to form soon after high tide and last until the next low water; the gyre structure is transported about the bay with the bulk advection of tidal motion. This is the first time this feature has been observed and the significance of its consequences on water circulation will be the subject of future research.

Characterization of a restriction modification system from the commensal Escherichia coli strain A0 34/86 (O83:K24:H31).

PubMed

Weiserová, Marie; Ryu, Junichi

2008-06-27

Type I restriction-modification (R-M) systems are the most complex restriction enzymes discovered to date. Recent years have witnessed a renaissance of interest in R-M enzymes Type I. The massive ongoing sequencing programmes leading to discovery of, so far, more than 1 000 putative enzymes in a broad range of microorganisms including pathogenic bacteria, revealed that these enzymes are widely represented in nature. The aim of this study was characterisation of a putative R-M system EcoA0ORF42P identified in the commensal Escherichia coli A0 34/86 (O83: K24: H31) strain, which is efficiently used at Czech paediatric clinics for prophylaxis and treatment of nosocomial infections and diarrhoea of preterm and newborn infants. We have characterised a restriction-modification system EcoA0ORF42P of the commensal Escherichia coli strain A0 34/86 (O83: K24: H31). This system, designated as EcoAO83I, is a new functional member of the Type IB family, whose specificity differs from those of known Type IB enzymes, as was demonstrated by an immunological cross-reactivity and a complementation assay. Using the plasmid transformation method and the RM search computer program, we identified the DNA recognition sequence of the EcoAO83I as GGA(8N)ATGC. In consistence with the amino acids alignment data, the 3' TRD component of the recognition sequence is identical to the sequence recognized by the EcoEI enzyme. The A-T (modified adenine) distance is identical to that in the EcoAI and EcoEI recognition sites, which also indicates that this system is a Type IB member. Interestingly, the recognition sequence we determined here is identical to the previously reported prototype sequence for Eco377I and its isoschizomers. Putative restriction-modification system EcoA0ORF42P in the commensal Escherichia coli strain A0 34/86 (O83: K24: H31) was found to be a member of the Type IB family and was designated as EcoAO83I. Combination of the classical biochemical and bacterial genetics approaches with comparative genomics might contribute effectively to further classification of many other putative Type-I enzymes, especially in clinical samples.

Vegetation in drylands: Effects on wind flow and aeolian sediment transport

USDA-ARS?s Scientific Manuscript database

Drylands are characterised by patchy vegetation, erodible surfaces and erosive aeolian processes. Empirical and modelling studies have shown that vegetation elements provide drag on the overlying airflow, thus affecting wind velocity profiles and altering erosive dynamics on desert surfaces. However...

Theoretical Studies of Strongly Interacting Fine Particle Systems

NASA Astrophysics Data System (ADS)

Fearon, Michael

Available from UMI in association with The British Library. A theoretical analysis of the time dependent behaviour of a system of fine magnetic particles as a function of applied field and temperature was carried out. The model used was based on a theory assuming Neel relaxation with a distribution of particle sizes. This theory predicted a linear variation of S_{max} with temperature and a finite intercept, which is not reflected by experimental observations. The remanence curves of strongly interacting fine-particle systems were also investigated theoretically. It was shown that the Henkel plot of the dc demagnetisation remanence vs the isothermal remanence is a useful representation of interactions. The form of the plot was found to be a reflection of the magnetic and physical microstructure of the material, which is consistent with experimental data. The relationship between the Henkel plot and the noise of a particulate recording medium, another property dependent on the microstructure, is also considered. The Interaction Field Factor (IFF), a single parameter characterising the non-linearity of the Henkel plot, is investigated. These results are consistent with a previous experimental study. Finally the results of the noise power spectral density for erased and saturated recording media are presented, so that characterisation of interparticle interactions may be carried out with greater accuracy.

Layered acoustofluidic resonators for the simultaneous optical and acoustic characterisation of cavitation dynamics, microstreaming, and biological effects.

PubMed

Pereno, V; Aron, M; Vince, O; Mannaris, C; Seth, A; de Saint Victor, M; Lajoinie, G; Versluis, M; Coussios, C; Carugo, D; Stride, E

2018-05-01

The study of the effects of ultrasound-induced acoustic cavitation on biological structures is an active field in biomedical research. Of particular interest for therapeutic applications is the ability of oscillating microbubbles to promote both cellular and tissue membrane permeabilisation and to improve the distribution of therapeutic agents in tissue through extravasation and convective transport. The mechanisms that underpin the interaction between cavitating agents and tissues are, however, still poorly understood. One challenge is the practical difficulty involved in performing optical microscopy and acoustic emissions monitoring simultaneously in a biologically compatible environment. Here we present and characterise a microfluidic layered acoustic resonator ( μ LAR) developed for simultaneous ultrasound exposure, acoustic emissions monitoring, and microscopy of biological samples. The μ LAR facilitates in vitro ultrasound experiments in which measurements of microbubble dynamics, microstreaming velocity fields, acoustic emissions, and cell-microbubble interactions can be performed simultaneously. The device and analyses presented provide a means of performing mechanistic in vitro studies that may benefit the design of predictable and effective cavitation-based ultrasound treatments.

Reaction mechanism interplay in determining the biological effectiveness of neutrons as a function of energy.

PubMed

Baiocco, G; Alloni, D; Babini, G; Mariotti, L; Ottolenghi, A

2015-09-01

Neutron relative biological effectiveness (RBE) is found to be energy dependent, being maximal for energies ∼1 MeV. This is reflected in the choice of radiation weighting factors wR for radiation protection purposes. In order to trace back the physical origin of this behaviour, a detailed study of energy deposition processes with their full dependences is necessary. In this work, the Monte Carlo transport code PHITS was used to characterise main secondary products responsible for energy deposition in a 'human-sized' soft tissue spherical phantom, irradiated by monoenergetic neutrons with energies around the maximal RBE/wR. Thereafter, results on the microdosimetric characterisation of secondary protons were used as an input to track structure calculations performed with PARTRAC, thus evaluating the corresponding DNA damage induction. Within the proposed simplified approach, evidence is suggested for a relevant role of secondary protons in inducing the maximal biological effectiveness for 1 MeV neutrons. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hard ceramic coatings: an experimental study on a novel damping treatment

NASA Astrophysics Data System (ADS)

Patsias, Sophoclis; Tassini, Nicola; Stanway, Roger

2004-07-01

This paper describes a novel damping treatment, namely hard ceramic coatings. These materials can be applied on almost any surface (internal or external) of a component. Their effect is the significant reduction of vibration levels and hence the extension of life expectancy of the component. The damping features of air-plasma-sprayed ceramic coatings (for example amplitude dependence, influence of initial amplitude) are discussed and the experimental procedure employed for testing and characterising such materials is also described. This test procedure is based around a custom-developed rig that allows one to measure the damping (internal friction) of specimens at controlled frequencies, strain amplitudes and, if required, various temperatures. A commonly used Thermal Barrier Coating, Yttria Stabilised Zirconia (8%), is used to demonstrate the above mentioned features. The damping effectiveness of this coating is then compared against two established damping treatments: polymer Free Layer Damping (FLD) and Constrained Layer Damping (CLD). The paper discusses the major issues in characterising ceramic damping coatings and their damping effectiveness when compared against the "traditional" approaches. Finally, the paper concludes with suggestions for further research.

Accuracy and cost-effectiveness of dynamic contrast-enhanced CT in the characterisation of solitary pulmonary nodules-the SPUtNIk study.

PubMed

Qureshi, N R; Rintoul, R C; Miles, K A; George, S; Harris, S; Madden, J; Cozens, K; Little, L A; Eichhorst, K; Jones, J; Moate, P; McClement, C; Pike, L; Sinclair, D; Wong, W L; Shekhdar, J; Eaton, R; Shah, A; Brindle, L; Peebles, C; Banerjee, A; Dizdarevic, S; Han, S; Poon, F W; Groves, A M; Kurban, L; Frew, A J; Callister, M E; Crosbie, P; Gleeson, F V; Karunasaagarar, K; Kankam, O; Gilbert, F J

2016-01-01

Solitary pulmonary nodules (SPNs) are common on CT. The most cost-effective investigation algorithm is still to be determined. Dynamic contrast-enhanced CT (DCE-CT) is an established diagnostic test not widely available in the UK currently. The SPUtNIk study will assess the diagnostic accuracy, clinical utility and cost-effectiveness of DCE-CT, alongside the current CT and 18-flurodeoxyglucose-positron emission tomography) ( 18 FDG-PET)-CT nodule characterisation strategies in the National Health Service (NHS). Image acquisition and data analysis for 18 FDG-PET-CT and DCE-CT will follow a standardised protocol with central review of 10% to ensure quality assurance. Decision analytic modelling will assess the likely costs and health outcomes resulting from incorporation of DCE-CT into management strategies for patients with SPNs. Approval has been granted by the South West Research Ethics Committee. Ethics reference number 12/SW/0206. The results of the trial will be presented at national and international meetings and published in an Health Technology Assessment (HTA) Monograph and in peer-reviewed journals. ISRCTN30784948; Pre-results.

Synthesis and Characterisation of Photocrosslinked poly(ethylene glycol) diacrylate Implants for Sustained Ocular Drug Delivery.

PubMed

McAvoy, Kathryn; Jones, David; Thakur, Raghu Raj Singh

2018-01-16

To investigate the sustained ocular delivery of small and large drug molecules from photocrosslinked poly(ethylene glycol) diacrylate (PEGDA) implants with varying pore forming agents. Triamcinolone acetonide and ovalbumin loaded photocrosslinked PEGDA implants, with or without pore-forming agents, were fabricated and characterised for chemical, mechanical, swelling, network parameters, as well as drug release and biocompatibility. HPLC-based analytical methods were employed for analysis of two molecules; ELISA was used to demonstrate bioactivity of ovalbumin. Regardless of PEGDA molecular weight or pore former composition all implants loaded with triamcinolone acetonide released significantly faster than those loaded with ovalbumin. Higher molecular weight PEGDA systems (700 Da) resulted in faster drug release of triamcinolone acetonide than their 250 Da counterpart. All ovalbumin released over the 56-day time period was found to be bioactive. Increasing PEGDA molecular weight resulted in increased system swelling, decreased crosslink density (Ve), increased polymer-water interaction parameter (χ), increased average molecular weight between crosslinks (Mc) and increased mesh size (ε). SEM studies showed the porosity of implants increased with increasing PEGDA molecular weight. Biocompatibility showed both PEGDA molecular weight implants were non-toxic when exposed to retinal epithelial cells over a 7-day period. Photocrosslinked PEGDA implant based systems are capable of controlled drug release of both small and large drug molecules through adaptations in the polymer system network. We are currently continuing evaluation of these systems as potential sustained drug delivery devices.

Student Engagement: Stakeholder Perspectives on Course Representation in University Governance

ERIC Educational Resources Information Center

Carey, Philip

2013-01-01

Student engagement has become a key feature of UK higher education policy and analysis. At the core of this is a notion of engagement characterised by dialogue and joint venture. The article explores this by considering the role of student representation in university governance. It focuses on the system of course representation that is a feature…

Adapting the Bilingual Aphasia Test to Rarotongan (Cook Islands Maori): Linguistic and Clinical Considerations

ERIC Educational Resources Information Center

Amberber, Amanda Miller

2011-01-01

This article describes the adaptation of the Bilingual Aphasia Test (BAT) to the Rarotongan dialect of Cook Islands Maori, a Polynesian language spoken in the Cook Islands and expatriate communities. A brief linguistic sketch of Rarotongan is presented. As Rarotongan is characterised by a complex pronominal system, "a" versus "o" possession and…

Empirical Validation of the Importance of Employees' Learning Motivation for Workplace E-Learning in Taiwanese Organisations

ERIC Educational Resources Information Center

Chen, Hsiu-Ju; Kao, Chia-Hung

2012-01-01

E-learning systems, adopted by organisations for employee training to enhance employees' performance, are characterised by self-directed, autonomous learning. Learning motivation is then of importance in the design of e-learning practices in workplace. However, empirical study of the alignment of e-learning with individual learning needs and…

Complex Contexts: Women and Community-Higher-Education in Ireland

ERIC Educational Resources Information Center

Quilty, Aideen; McAuliffe, Mary; Barry, Ursula

2016-01-01

Education is not a neutral process, it can be used to establish and maintain conformity or be part of a process of liberation and social change (Freire, 1979; hooks, 1994). The Irish State's failure to acknowledge this lack of neutrality has characterised the formal education system in Ireland since its inception. From the introduction of the…

Red flags: a case series of clinician-family communication challenges in the context of CHD.

PubMed

Sekar, Priya; Marcus, Katie L; Williams, Erin P; Boss, Renee D

2017-07-01

We describe three cases of newborns with complex CHD characterised by communication challenges. These communication challenges were categorised as patient, family, or system-related red flags. Strategies for addressing these red flags were proposed, for the goal of optimising care and improving quality of life in this vulnerable population.

Teacher Education in France under the Hollande Government: Reconstructing and Reinforcing the Republic

ERIC Educational Resources Information Center

Hyatt, David; Meraud, Julie

2015-01-01

Successive republican governments in France have constructed a complex educational context, which is rhetorically committed to a myth of provision of educational equality of opportunity whilst in practical terms it is characterised by a system focused on the production and reproduction of elites. This article aims to consider the political drivers…

Transition Systems and Non-Standard Employment in Early Career: Comparing Japan and Switzerland

ERIC Educational Resources Information Center

Imdorf, Christian; Helbling, Laura Alexandra; Inui, Akio

2017-01-01

Even though Japan and Switzerland are characterised by comparatively low youth unemployment rates, non-standard forms of employment are on the rise, posing a risk to the stable integration of young labour market entrants. Drawing on the French approach of societal analysis, this paper investigates how country-specific school-to-work transition…

Processes and Stages of Differentiation in European Higher Education

ERIC Educational Resources Information Center

Goglio, Valentina; Regini, Marino

2017-01-01

In this article we discuss processes of internal differentiation that have characterised European higher education systems in the last 50 years. We argue that these processes have gone through two main stages and in two different directions, each of which is showing its limits in the long run. Therefore, we expect a third stage of differentiation,…

Lessons Learnt from Teachers' Perspectives on Mobile Learning in South Africa with Cultural and Linguistic Constraints

ERIC Educational Resources Information Center

Jantjies, Mmaki; Joy, Mike

2016-01-01

South Africa's classrooms are characterised by a wide variety of cultural and linguistic differences, providing teachers with educational challenges, particularly in mathematics and science subjects. In response, various mobile learning systems have been developed and piloted in the North West and Gauteng Provinces of South Africa. A framework has…

Brillouin characterisation of optical microfibers

NASA Astrophysics Data System (ADS)

Farhan, Kazi Tasneem

The sleek shape of microfiber helps it to confine the light tightly and generate high nonlinear effect, which is 1000 times higher than the standard fiber. This project focuses on fabricating microfiber samples with different taper lengths and different waist diameter from three different kinds of fiber, single mode fiber (SMF), Gedoped and Ga-doped. All the samples were characterised in terms of Brillouin scattering and Brillouin gain and Brillouin lasing, and compared to each other and to the SMF fiber. Stimulated Brillouin scattering (SBS) has been demonstrated for short microfibers of length less than 10cm. The nonlinear effects of long tapers have not been reported yet. The theoretical perspective related to microfibers indicate the possibility of generation of stronger signals and newer frequencies. Among the many nonlinear effects Brillouin scattering is the easiest to observe and has not been studied using long microfibers until now. In this project microfibers of different lengths and waist diameter are fabricated. The microfibers were made from three different kinds of fiber: SMF, Germanium doped (Ge-doped) and Gallium doped (Ga-doped). The shapes of the fabricated samples are profiled to match the shape with the numerically simulated shape. The power performances are studied so that samples with minimum losses are used for Brillouin characterisation. The first experiment uses the microfiber samples for testing and recording the changes in Stokes generation for the different dimensions of each sample in a Brillouin scattering setup. These microfibers are tested in s second experiment of Brillouin laser setup to explore their possibilities of lasing. In the third experiment the microfibers are used in a pump probe technique setup to spatially measure the Brillouin gain along the length of each sample.

DNA damage protection by bulk and nano forms of quercetin in lymphocytes of patients with chronic obstructive pulmonary disease exposed to the food mutagen 2-amino-3-methylimidazo [4,5-f]quinolone (IQ).

PubMed

Habas, Khaled; Abdulmwli, Mhamoued; Demir, Eşref; Jacob, Badie K; Najafzadeh, Mojgan; Anderson, Diana

2018-05-25

Chronic obstructive pulmonary disease (COPD) in humans, describes a group of lung conditions characterised by airflow limitation that is poorly reversible. The airflow limitation usually progresses slowly and is related to an abnormal inflammatory response of the lung to toxic particles. COPD is characterised by oxidative stress and an increased risk of lung carcinoma. The 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) is one of a number of mutagenic/carcinogenic heterocyclic amines found mainly in well-cooked meats which are thus part of the regular diet. Antioxidants are very important in order to protect the cells against oxidative damage. The aim of the present study was to assess the effects of IQ on the level of DNA damage and susceptibility to a potent mutagen in peripheral blood cells of COPD patients. DNA damage and the frequency of micronuclei (MNi) were evaluated using the Comet and micronucleus assays, respectively. Differential expressions of both mRNA and protein of the endogenous antioxidant enzyme catalase were evaluated with quantitative polymerase chain reaction (qPCR) and Western blot analysis, respectively. Furthermore, the effect of bulk and nano forms of quercetin and their combination with IQ were examined. Results of the present study clearly demonstrated that MNi frequency in the peripheral blood lymphocytes exhibited a positive correlation with the DNA damage as evident from the different Comet assay parameters. Increase of the endogenous antioxidant catalase also showed there was a stimulation of this enzyme system by IQ. Whereas, the endogenous antioxidant quercetin significantly reduced oxidative stress in COPD patients and healthy individuals. Copyright © 2018 Elsevier Inc. All rights reserved.

Characterisation results of the CMOS VISNIR spectral band detector for the METimage instrument

NASA Astrophysics Data System (ADS)

Pratlong, Jérôme; Schmuelling, Frank; Benitez, Victor; Breart De Boisanger, Michel; Skegg, Michael; Simpson, Robert; Bowring, Steve; Krzizok, Natalie

2017-09-01

The METimage instrument is part of the EPS-SG (EUMETSAT Polar System Second Generation) program. It will be situated on the MetOp-SG platform which in operation has an objective of collecting data for meteorology and climate monitoring as well as their forecasting. Teledyne e2v has developed and characterised the CMOS VISNIR detector flight module part of the METimage instrument. This paper will focus on the silicon results obtained from the CMOS VISNIR detector flight model. The detector is a large multi-linear device composed of 7 spectral bands covering a wavelength range from 428 nm to 923 nm (some bands are placed twice and added together to enhance the signal-to-noise performance). This detector uses a 4T pixel, with a size of 250μm square, presenting challenges to achieve good charge transfer efficiency with high conversion factor and good linearity for signal levels up to 2M electrons and with high line rates. Low noise has been achieved using correlated double sampling to suppress the read-out noise and give a maximum dynamic range that is significantly larger than in standard commercial devices. The photodiode occupies a significant fraction of the large pixel area. This makes it possible to meet the detection efficiency when front illuminated. A thicker than standard epitaxial silicon is used to improve NIR response. However, the dielectric stack on top of the sensor produces Fabry-Perot étalon effects, which are problematic for narrow band illumination as this causes the detection efficiency to vary significantly over a small wavelength range. In order to reduce this effect and to meet the specification, the silicon manufacturing process has been modified. The flight model will have black coating deposited between each spectral channel, onto the active silicon regions.

Early Potent Protection against Heterologous SIVsmE660 Challenge Following Live Attenuated SIV Vaccination in Mauritian Cynomolgus Macaques

PubMed Central

Berry, Neil; Ham, Claire; Mee, Edward T.; Rose, Nicola J.; Mattiuzzo, Giada; Jenkins, Adrian; Page, Mark; Elsley, William; Robinson, Mark; Smith, Deborah; Ferguson, Deborah; Towers, Greg; Almond, Neil; Stebbings, Richard

2011-01-01

Background Live attenuated simian immunodeficiency virus (SIV) vaccines represent the most effective means of vaccinating macaques against pathogenic SIV challenge. However, thus far, protection has been demonstrated to be more effective against homologous than heterologous strains. Immune correlates of vaccine-induced protection have also been difficult to identify, particularly those measurable in the peripheral circulation. Methodology/Principal Findings Here we describe potent protection in 6 out of 8 Mauritian-derived cynomolgus macaques (MCM) against heterologous virus challenge with the pathogenic, uncloned SIVsmE660 viral stock following vaccination with live attenuated SIVmac251/C8. MCM provided a characterised host genetic background with limited Major Histocompatibility Complex (MHC) and TRIM5α allelic diversity. Early protection, observed as soon as 3 weeks post-vaccination, was comparable to that of 20 weeks vaccination. Recrudescence of vaccine virus was most pronounced in breakthrough cases where simultaneous identification of vaccine and challenge viruses by virus-specific PCR was indicative of active co-infection. Persistence of the vaccine virus in a range of lymphoid tissues was typified by a consistent level of SIV RNA positive cells in protected vaccinates. However, no association between MHC class I /II haplotype or TRIM5α polymorphism and study outcome was identified. Conclusion/Significance This SIV vaccine study, conducted in MHC-characterised MCM, demonstrated potent protection against the pathogenic, heterologous SIVsmE660 challenge stock after only 3 weeks vaccination. This level of protection against this viral stock by intravenous challenge has not been hitherto observed. The mechanism(s) of protection by vaccination with live attenuated SIV must account for the heterologous and early protection data described in this study, including those which relate to the innate immune system. PMID:21853072

Spatio-temporal dynamics in phytobenthos structural properties reveal insights into agricultural catchment dynamics and nutrient fluxes

NASA Astrophysics Data System (ADS)

Reaney, S. M.; Snell, M. A.; Barker, P. A.; Aftab, A.; Barber, N. J.; Benskin, C.; Burke, S.; Cleasby, W.; Haygarth, P.; Jonczyk, J. C.; Owen, G. J.; Perks, M. T.; Quinn, P. F.; Surridge, B.

2016-12-01

Low order streams are spatially extensive, temporally dynamic, systems within the agricultural landscape. This dynamism extends to the aquatic communities within these streams, including the phytobentos, which demonstrates considerable resilience to diffuse anthropogenic nutrient pressures and changing climate dynamics. The phytobenthos community can substantially contribute to the food web, in particular diatoms, which dominate photo-autotrophic assemblages in low order streams. Diatoms are widely used in ecological monitoring because of their high sensitivity to environmental condition, but knowledge is limited on the ecological effects of winter disturbances and variance introduced by multiple and interacting pressures (N, P, sediment), introducing bias in understanding temporal dynamics in benthic diatom communities. Using the environmental time series data from long term monitoring within the River Eden Demonstration Test Catchment programme, we assess the impact of multiple hydro-chemical stressors on phytobenthic community resilience, and synthesize the impact of an extreme winter event. Monthly data from diatom communities collected in the Eden DTC from March 2011 to present show that river flow, strongly coupled to precipitation, is a key driver of these communities. Discharge has a direct effect on communities through scouring, but is also tightly correlated to nutrient delivery, such that 80% of the annual TP load arrives in 10% of the time. Trophic Diatom Index (TDI) values demonstrated considerable resilience by the stability of inter-monthly TDI scores over 5 seasonal cycles against the characterised highly variable hydrological regime. This research demonstrates that well characterised winter disturbances are critical to understanding drivers of aquatic dynamics. This has implications for catchment diffuse pollution policy, farm management and economics, given the climate projections of increases in frequency and intensity of extreme winter events, which may alter instream nutrient fluxes.

Effective and Inclusive Schools? Attention to Diversity in Highly Effective Schools in the Autonomous Region of the Basque Country

ERIC Educational Resources Information Center

Intxausti, Nahia; Etxeberria, Feli; Bartau, Isabel

2017-01-01

This paper forms part of a research project that aims to characterise best practices in highly effective schools in the Autonomous Region of the Basque Country (ARBC). The aim is for the best practices identified to serve as points of reference when designing improvement plans to be implemented in all schools in the ARBC, with the advice and…

The design and realisation of the IXV Mission Analysis and Flight Mechanics

NASA Astrophysics Data System (ADS)

Haya-Ramos, Rodrigo; Blanco, Gonzalo; Pontijas, Irene; Bonetti, Davide; Freixa, Jordi; Parigini, Cristina; Bassano, Edmondo; Carducci, Riccardo; Sudars, Martins; Denaro, Angelo; Angelini, Roberto; Mancuso, Salvatore

2016-07-01

The Intermediate eXperimental Vehicle (IXV) is a suborbital re-entry demonstrator successfully launched in February 2015 focusing on the in-flight demonstration of a lifting body system with active aerodynamic control surfaces. This paper presents an overview of the Mission Analysis and Flight Mechanics of the IXV vehicle, which comprises computation of the End-to-End (launch to splashdown) design trajectories, characterisation of the Entry Corridor, assessment of the Mission Performances through Monte Carlo campaigns, contribution to the aerodynamic database, analysis of the Visibility and link budget from Ground Stations and GPS, support to safety analyses (off nominal footprints), specification of the Centre of Gravity box, selection of the Angle of Attack trim line to be flown and characterisation of the Flying Qualities performances. An initial analysis and comparison with the raw flight data obtained during the flight will be discussed and first lessons learned derived.

(60)Co in cast steel matrix: A European interlaboratory comparison for the characterisation of new activity standards for calibration of gamma-ray spectrometers in metallurgy.

PubMed

Tzika, Faidra; Burda, Oleksiy; Hult, Mikael; Arnold, Dirk; Marroyo, Belén Caro; Dryák, Pavel; Fazio, Aldo; Ferreux, Laurent; García-Toraño, Eduardo; Javornik, Andrej; Klemola, Seppo; Luca, Aurelian; Moser, Hannah; Nečemer, Marijan; Peyrés, Virginia; Reis, Mario; Silva, Lidia; Šolc, Jaroslav; Svec, Anton; Tyminski, Zbigniew; Vodenik, Branko; Wätjen, Uwe

2016-08-01

Two series of activity standards of (60)Co in cast steel matrix, developed for the calibration of gamma-ray spectrometry systems in the metallurgical sector, were characterised using a European interlaboratory comparison among twelve National Metrology Institutes and one international organisation. The first standard, consisting of 14 disc shaped samples, was cast from steel contaminated during production ("originally"), and the second, consisting of 15 similar discs, from artificially-contaminated ("spiked") steel. The reference activity concentrations of (60)Co in the cast steel standards were (1.077±0.019) Bqg(-1) on 1 January 2013 12h00 UT and (1.483±0.022) Bqg(-1) on 1 June 2013 12h00 UT, respectively. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characterisation of medical-waste sterilisation-plant wastewater and a preliminary study of coagulation-flocculation treatment options.

PubMed

Ozkan, O; Mihçiokur, H; Azgin, S T; Ozdemir, O

2010-01-01

Wastewater from a medical-waste sterilisation plant (MWSP) contains unique pollutants and requires on-site treatment to prevent contamination of the municipal sewage system and receiving water bodies. Therefore, to meet the prescribed discharge standards and comply with the legal regulations, pre-treatment must be applied to MWSP wastewater. In this study, the capabilities of coagulation-flocculation processes were investigated for MWSP wastewater treatment. Processes using ferric chloride, ferrous sulfate and aluminium sulfate as coagulants were characterised. During the coagulation experiments, seven different coagulant dosages and four different pH values were evaluated to determine the optimum coagulant dosage and pH value. The highest removal efficiency of chemical oxygen demand (COD) was obtained using 300 mg/L of ferric chloride at pH 10. A COD removal of about 60% as well as considerable reductions in the amounts of suspended solids, nitrogen and phosphorus were realised.

Modification of semiconductor materials with the use of plasma produced by low intensity repetitive laser pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolowski, J.; Rosinski, M.; Badziak, J.

2008-03-19

This work reports experiments concerning specific application of laser-produced plasma at IPPLM in Warsaw. A repetitive pulse laser system of parameters: energy up to 0.8 J in a 3.5 ns-pulse, wavelength of 1.06 {mu}m, repetition rate of up to 10 Hz, has been employed in these investigations. The characterisation of laser-produced plasma was performed with the use of 'time-of-flight' ion diagnostics simultaneously with other diagnostic methods. The results of laser-matter interaction were obtained in dependence on laser pulse parameters, illumination geometry and target material. The modified SiO{sub 2} layers and sample surface properties were characterised with the use of differentmore » methods at the Middle-East Technological University in Ankara and at the Warsaw University of technology. The production of the Ge nanocrystallites has been demonstrated for annealed samples prepared in different experimental conditions.« less

Sheet metals characterization using the virtual fields method

NASA Astrophysics Data System (ADS)

Marek, Aleksander; Davis, Frances M.; Pierron, Fabrice

2018-05-01

In this work, a characterisation method involving a deep-notched specimen subjected to a tensile loading is introduced. This specimen leads to heterogeneous states of stress and strain, the latter being measured using a stereo DIC system (MatchID). This heterogeneity enables the identification of multiple material parameters in a single test. In order to identify material parameters from the DIC data, an inverse method called the Virtual Fields Method is employed. The method combined with recently developed sensitivity-based virtual fields allows to optimally locate areas in the test where information about each material parameter is encoded, improving accuracy of the identification over the traditional user-defined virtual fields. It is shown that a single test performed at 45° to the rolling direction is sufficient to obtain all anisotropic plastic parameters, thus reducing experimental effort involved in characterisation. The paper presents the methodology and some numerical validation.

Effects of Related and Unrelated Context on Recall and Recognition by Adults with High-Functioning Autism Spectrum Disorder

ERIC Educational Resources Information Center

Bowler, Dermot M.; Gaigg, Sebastian B.; Gardiner, John M.

2008-01-01

Memory in autism spectrum disorder (ASD) is characterised by greater difficulties with recall rather than recognition and with a diminished use of semantic or associative relatedness in the aid of recall. Two experiments are reported that test the effects of item-context relatedness on recall and recognition in adults with high-functioning ASD…

Production, characterisation, and cytocompatibility of porous titanium-based particulate scaffolds.

PubMed

Luthringer, B J C; Ali, F; Akaichi, H; Feyerabend, F; Ebel, T; Willumeit, R

2013-10-01

Despite its non-matching mechanical properties titanium remains the preferred metal implant material in orthopaedics. As a consequence in some cases stress shielding effect occurs, leading to implant loosening, osteopenia, and finally revision surgery. Porous metal scaffolds to allow easier specialised cells ingrowth with mechanical properties closer to the ones of bone can overcome this problem. This should improve healing processes, implant integration, and dynamic strength of implants retaining. Three Ti-6Al-4V materials were metal injection moulded and tailored porosities were effectively achieved. After microstructural and mechanical characterisation, two different primary cells of mesenchymal origin (human umbilical cord perivascular cells and human bone derived cells which revealed to be two pertinent models) as well as one cell line originated from primary osteogenic sarcoma, Saos-2, were bestowed to investigate cell-material interaction on genomic and proteome levels. Biological examinations disclosed that no material has negative impact on early adhesion, proliferation or cell viability. An efficient cell ingrowth into material with an average porosity of 25-50 μm was proved.

The importance of chill rate when characterising colour change of lamb meat during retail display.

PubMed

Jacob, R H; Thomson, K L

2012-02-01

An experiment was conducted to compare the effect of two chilling rates (Con and Fast) on colour change of lamb meat during simulated retail display. Measurements were made on 3 muscles; LD (m. longisimuss dorsi), SM (m semimembranosus) and ST (m. semitendinous). Meat samples from 32 Merino crossbred lambs were vacuum packed and stored for 5 days at 2 °C, then cut and overwrapped in polyvinyl chloride film on black polystyrene trays, stored in a display cabinet at 4 °C with lights on and measured twice daily for 4 days, using a Hunterlab minilab 45/20L D65, aperture 10°. Sarcomere length was shorter, shear force higher and colour change greater in meat from the Fast treatment compared to the Con treatment. Colour differences between treatments were likely due to oxygenation (bloom) as well as oxidation effects. Chill rate is important when characterising colour change during display and should be considered in measurement protocols. Copyright © 2011 Elsevier Ltd. All rights reserved.

Controllably annealed CuO-nanoparticle modified ITO electrodes: Characterisation and electrochemical studies

NASA Astrophysics Data System (ADS)

Wang, Tong; Su, Wen; Fu, Yingyi; Hu, Jingbo

2016-12-01

In this paper, we report a facile and controllable two-step approach to produce indium tin oxide electrodes modified by copper(II) oxide nanoparticles (CuO/ITO) through ion implantation and annealing methods. After annealing treatment, the surface morphology of the CuO/ITO substrate changed remarkably and exhibited highly electroactive sites and a high specific surface area. The effects of annealing treatment on the synthesis of CuO/ITO were discussed based on various instruments' characterisations, and the possible mechanism by which CuO nanoparticles were generated was also proposed in this work. Cyclic voltammetric results indicated that CuO/ITO electrodes exhibited effective catalytic responses toward glucose in alkaline solution. Under optimal experimental conditions, the proposed CuO/ITO electrode showed sensitivity of 450.2 μA cm-2 mM-1 with a linear range of up to ∼4.4 mM and a detection limit of 0.7 μM (S/N = 3). Moreover, CuO/ITO exhibited good poison resistance, reproducibility, and stability properties.

Fabrication and characterisation of phantom material made of Tannin-added Rhizophora spp. particleboards for photon and electron beams

NASA Astrophysics Data System (ADS)

Yusof, M. F. Mohd; Hamid, P. N. K. Abd; Tajuddin, A. A.; Hashim, R.; Bauk, S.; Isa, N. Mohd; Isa, M. J. Md

2017-05-01

Particleboards made of Rhizophora spp. with addition of tannin adhesive were fabricated at target density of 1.0 g/cm3. The physical and mechanical properties of the particleboards including internal bond strength (IB) and modulus of rupture (MOR) were measured based on Japanese Industrial Standards (JIS A-5908). The characterisation of the particleboards including the effective atomic number, CT number and relative electron density were determined and compared to water. The mass attenuation coefficient of the particleboards were measured and compared to the calculated value of water using photon cross-section database (XCOM). The results showed that the physical and mechanical properties of the particleboards complied with Type 13 and 18 of JIS A-5908. The values of effective atomic number, CT number and relative electron density were also close to the value of water. The value of mass attenuation coefficients of the particleboards showed good agreement with water (XCOM) at low and high energy photon indicated by the χ2 values.

Characteristics of women with nausea and vomiting of pregnancy who chose to continue compassionate use of placebo after a randomised trial.

PubMed

Matok, I; Umans, J; Feghali, M N; Clark, S; Caritis, S; Miodovnik, M; Hankins, G; Mattison, D R; Nordeng, H; Koren, G

2013-08-01

The placebo effect has not been characterised in pregnant women suffering from nausea and vomiting of pregnancy (NVP). Our aim was to characterise determinants of the placebo effect in women treated with placebo for NVP. We analysed data from a multicentre, double blind randomised controlled trial of Diclectin (delayed release doxylamine and pyridoxine) vs placebo for the treatment of NVP. A total of 127 women in the placebo arm and 130 in the active arm provided evaluable data for this analysis. Women who chose to continue placebo on a compassionate basis (n = 41) had significantly better improvement in symptoms of NVP and higher Wellbeing scores than those who did not ask to continue compassionate use. Results were similar in the active drug arm. The request to continue compassionate use of either placebo or active drug could be predicted by greater improvement in symptoms of NVP during the trial period.

Visual texture for automated characterisation of geological features in borehole televiewer imagery

NASA Astrophysics Data System (ADS)

Al-Sit, Waleed; Al-Nuaimy, Waleed; Marelli, Matteo; Al-Ataby, Ali

2015-08-01

Detailed characterisation of the structure of subsurface fractures is greatly facilitated by digital borehole logging instruments, the interpretation of which is typically time-consuming and labour-intensive. Despite recent advances towards autonomy and automation, the final interpretation remains heavily dependent on the skill, experience, alertness and consistency of a human operator. Existing computational tools fail to detect layers between rocks that do not exhibit distinct fracture boundaries, and often struggle characterising cross-cutting layers and partial fractures. This paper presents a novel approach to the characterisation of planar rock discontinuities from digital images of borehole logs. Multi-resolution texture segmentation and pattern recognition techniques utilising Gabor filters are combined with an iterative adaptation of the Hough transform to enable non-distinct, partial, distorted and steep fractures and layers to be accurately identified and characterised in a fully automated fashion. This approach has successfully detected fractures and layers with high detection accuracy and at a relatively low computational cost.

The nitrogen cycle in highly urbanized tropical regions and the effect of river-aquifer interactions: The case of Jakarta and the Ciliwung River

NASA Astrophysics Data System (ADS)

Costa, Diogo; Burlando, Paolo; Priadi, Cindy; Shie-Yui, Liong

2016-09-01

Groundwater is extensively used in Jakarta to compensate for the limited public water supply network. Recent observations show a rise in nitrate (NO3-) levels in the shallow aquifer, thus pointing at a potential risk for public health. The detected levels are still below national and international regulatory limits for drinking water but a strategy is necessary to contain the growing problem. We combine 3 years of available data in the Ciliwung River, the major river flowing through Jakarta, with a distributed river-aquifer interaction model to characterise the impact of urbanisation on the N-cycle of both surface and groundwater systems. Results show that the N-cycle in the river-aquifer system is heterogeneous in space, seasonal dependent (i.e. flow regime) and strongly affected by urban pollution. Results suggest also that although the main sources of N related groundwater pollution are leaking septic tanks, the aquifer interaction with the Ciliwung River may locally have a strong effect on the concentrations. In the general context of pollution control in urban areas, this study demonstrates how advanced process-based models can be efficiently used in combination with field measurements to bring new insights into complex contamination problems. These are essential for more effective and integrated management of water quality in river-aquifer systems.

The nitrogen cycle in highly urbanized tropical regions and the effect of river-aquifer interactions: The case of Jakarta and the Ciliwung River.

PubMed

Costa, Diogo; Burlando, Paolo; Priadi, Cindy; Shie-Yui, Liong

2016-09-01

Groundwater is extensively used in Jakarta to compensate for the limited public water supply network. Recent observations show a rise in nitrate (NO3(-)) levels in the shallow aquifer, thus pointing at a potential risk for public health. The detected levels are still below national and international regulatory limits for drinking water but a strategy is necessary to contain the growing problem. We combine 3years of available data in the Ciliwung River, the major river flowing through Jakarta, with a distributed river-aquifer interaction model to characterise the impact of urbanisation on the N-cycle of both surface and groundwater systems. Results show that the N-cycle in the river-aquifer system is heterogeneous in space, seasonal dependent (i.e. flow regime) and strongly affected by urban pollution. Results suggest also that although the main sources of N related groundwater pollution are leaking septic tanks, the aquifer interaction with the Ciliwung River may locally have a strong effect on the concentrations. In the general context of pollution control in urban areas, this study demonstrates how advanced process-based models can be efficiently used in combination with field measurements to bring new insights into complex contamination problems. These are essential for more effective and integrated management of water quality in river-aquifer systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Diversity in livestock resources in pastoral systems in Africa.

PubMed

Kaufmann, B A; Lelea, M A; Hulsebusch, C G

2016-11-01

Pastoral systems are important producers and repositories of livestock diversity. Pastoralists use variability in their livestock resources to manage high levels of environmental variability in economically advantageous ways. In pastoral systems, human-animal-environment interactions are the basis of production and the key to higher productivity and efficiency. In other words, pastoralists manage a production system that exploits variability and keeps production costs low. When differentiating, characterising and evaluating pastoral breeds, this context-specific, functional dimension of diversity in livestock resources needs to be considered. The interaction of animals with their environment is determined not only by morphological and physiological traits but also by experience and socially learned behaviour. This high proportion of non-genetic components determining the performance of livestock means that current models for analysing livestock diversity and performance, which are based on genetic inheritance, have limited ability to describe pastoral performance. There is a need for methodological innovations to evaluate pastoral breeds and animals, since comparisons based on performance 'under optimal conditions' are irrelevant within this production system. Such innovations must acknowledge that livestock or breed performance is governed by complex human-animal-environment interactions, and varies through time and space due to the mobile and seasonal nature of the pastoral system. Pastoralists' breeding concepts and selection strategies seem to be geared towards improving their animals' capability to exploit variability, by - among other things - enhancing within-breed diversity. In-depth studies of these concepts and strategies could contribute considerably towards developing methodological innovations for the characterisation and evaluation of pastoral livestock resources.

A model of economic growth with physical and human capital: The role of time delays.

PubMed

Gori, Luca; Guerrini, Luca; Sodini, Mauro

2016-09-01

This article aims at analysing a two-sector economic growth model with discrete delays. The focus is on the dynamic properties of the emerging system. In particular, this study concentrates on the stability properties of the stationary solution, characterised by analytical results and geometrical techniques (stability crossing curves), and the conditions under which oscillatory dynamics emerge (through Hopf bifurcations). In addition, this article proposes some numerical simulations to illustrate the behaviour of the system when the stationary equilibrium is unstable.

Mycobacterium tuberculosis infection in grazing cattle in central Ethiopia.

PubMed

Ameni, Gobena; Vordermeier, Martin; Firdessa, Rebuma; Aseffa, Abraham; Hewinson, Glyn; Gordon, Stephen V; Berg, Stefan

2011-06-01

A preliminary study to characterise mycobacteria infecting tuberculous cattle from two different management systems in central Ethiopia was carried out. Approximately 27% of isolates from grazing cattle were Mycobacterium tuberculosis, while cattle in a more intensive-production system were exclusively infected with M. bovis. The practice of local farmers discharging chewed tobacco directly into the mouths of pastured cattle was identified as a potential route of human-to-cattle transmission of M. tuberculosis. Copyright © 2010 Elsevier Ltd. All rights reserved.

Characterisation of anti-erosive properties of nanocomposite coatings by the methods of sclerometry

NASA Astrophysics Data System (ADS)

Kudryakov, O. V.; Varavka, V. N.; Ilyasov, V. V.

2017-05-01

Results of research of coatings of the different metal-ceramics systems are given. Coatings were received by ion-plasma sedimentation in vacuum in the form of multilayered composite material, which had a thickness of layers within nanometric range. Selection of composite systems is determined by applied research problem - namely designing of the anti-erosive coatings durable in the condition of drop impingement impacts. For this purpose the sclerometric studies, the bench erosive tests and optimization of the obtained data were done.

Pressure changes of volcanic systems derived from seismic signals

NASA Astrophysics Data System (ADS)

Neuberg, J. W.; Sturton, S.

2002-12-01

Seismic low-frequency events from Soufriere Hills volcano in Montserrat are a superposition of single interface waves travelling along the conduit and leaking into teh volcanic edifice at the upper end of a conduit section where magma properties change rapidly. These low-frequency signals are largely characterised by the intermittency of the interface waves, as well as by the dispersion effects they encounter. Using finite difference modelling of the seismic wavefield together with simultaneous modelling of magma properties in time and at depth, allows us to link the seismic signature directly to magma and conduit parameters. We retrieve a relationship between frequency content of seismic signals and governing pressure in the magma which enables us to determine the pressure changes in the magma from spectral characteristics and their temporal changes.

Studies of LSO:Tb radio-luminescence properties using white beam hard X-ray synchrotron irradiation

NASA Astrophysics Data System (ADS)

Cecilia, A.; Rack, A.; Pelliccia, D.; Douissard, P.-A.; Martin, T.; Couchaud, M.; Dupré, K.; Baumbach, T.

A radio-luminescence set-up was installed at the synchrotron light source ANKA to characterise scintillators under the high X-ray photon flux density of white beam synchrotron radiation. The system allows for investigating the radio-luminescence spectrum of the material under study as well as analysing in situ changes of its scintillation behaviour (e.g. under heat load and/or intensive ionising radiation). In this work we applied the radio-luminescence set-up for investigating the radiation damage effects on the luminescence properties of a new kind of thin single crystal scintillator for high resolution X-ray imaging based on a layer of modified Lu2SiO5 grown by liquid phase epitaxy on a dedicated substrate within the framework of an EC project (SCINTAX).

Integration of community structure data reveals observable effects below sediment guideline thresholds in a large estuary.

PubMed

Tremblay, Louis A; Clark, Dana; Sinner, Jim; Ellis, Joanne I

2017-09-20

The sustainable management of estuarine and coastal ecosystems requires robust frameworks due to the presence of multiple physical and chemical stressors. In this study, we assessed whether ecological health decline, based on community structure composition changes along a pollution gradient, occurred at levels below guideline threshold values for copper, zinc and lead. Canonical analysis of principal coordinates (CAP) was used to characterise benthic communities along a metal contamination gradient. The analysis revealed changes in benthic community distribution at levels below the individual guideline values for the three metals. These results suggest that field-based measures of ecological health analysed with multivariate tools can provide additional information to single metal guideline threshold values to monitor large systems exposed to multiple stressors.

RETENTION OF POLYURETHANE FOAM FRAGMENTS DURING VAC-THERAPY, A COMPLICATION TO BE CONSIDERED

PubMed Central

Dessy, L.A.; Serratore, F.; Corrias, F.; Parisi, P.; Mazzocchi, M.; Carlesimo, B.

2013-01-01

VAC-therapy is a closed-loop, non-invasive active system, characterised by a controlled and localized negative pressure applied on porous polyurethane absorbent foams. It promotes healing of acute and chronic wounds. Therapeutic effects of VAC-therapy have been proved and demonstrated, however this method can have some disadvantages. Even if it is a quite versatile device, only qualified medical/paramedical personnel should use it in order to avoid possible complications that can occur after an improper application. In this report, 11 cases of foam fragment retention within the wound are presented. This rare complication did not promote healing, but further hindered it. On the basis of our experience, it is mandatory to define indications, benefits and limitations of the VAC-therapy. PMID:23590296

Using kites for 3-D mapping of gullies at decimetre-resolution over several square kilometres: a case study on the Kamech catchment, Tunisia

NASA Astrophysics Data System (ADS)

Feurer, Denis; Planchon, Olivier; Amine El Maaoui, Mohamed; Ben Slimane, Abir; Rached Boussema, Mohamed; Pierrot-Deseilligny, Marc; Raclot, Damien

2018-06-01

Monitoring agricultural areas threatened by soil erosion often requires decimetre topographic information over areas of several square kilometres. Airborne lidar and remotely piloted aircraft system (RPAS) imagery have the ability to provide repeated decimetre-resolution and -accuracy digital elevation models (DEMs) covering these extents, which is unrealistic with ground surveys. However, various factors hamper the dissemination of these technologies in a wide range of situations, including local regulations for RPAS and the cost for airborne laser systems and medium-format RPAS imagery. The goal of this study is to investigate the ability of low-tech kite aerial photography to obtain DEMs with decimetre resolution and accuracy that permit 3-D descriptions of active gullying in cultivated areas of several square kilometres. To this end, we developed and assessed a two-step workflow. First, we used both heuristic experimental approaches in field and numerical simulations to determine the conditions that make a photogrammetric flight possible and effective over several square kilometres with a kite and a consumer-grade camera. Second, we mapped and characterised the entire gully system of a test catchment in 3-D. We showed numerically and experimentally that using a thin and light line for the kite is key for a complete 3-D coverage over several square kilometres. We thus obtained a decimetre-resolution DEM covering 3.18 km2 with a mean error and standard deviation of the error of +7 and 22 cm respectively, hence achieving decimetre accuracy. With this data set, we showed that high-resolution topographic data permit both the detection and characterisation of an entire gully system with a high level of detail and an overall accuracy of 74 % compared to an independent field survey. Kite aerial photography with simple but appropriate equipment is hence an alternative tool that has been proven to be valuable for surveying gullies with sub-metric details in a square-kilometre-scale catchment. This case study suggests that access to high-resolution topographic data on these scales can be given to the community, which may help facilitate a better understanding of gullying processes within a broader spectrum of conditions.

Geochemical characterisation of Taal volcano-hydrothermal system and temporal evolution during continued phases of unrest (1991-2017)

NASA Astrophysics Data System (ADS)

Maussen, Katharine; Villacorte, Edgardo; Rebadulla, Ryan R.; Maximo, Raymond Patrick; Debaille, Vinciane; Bornas, Ma. Antonia; Bernard, Alain

2018-02-01

Taal volcano (Luzon Island, Philippines) has last erupted in 1977 but has known some periods of increased activity, characterised by seismic swarms, ground deformation, increased carbon dioxide flux and in some cases temperature anomalies and the opening of fissures. We studied major, trace element and sulphur and strontium isotopic composition of Taal lake waters and hot springs over a period of 25 years to investigate the geochemical evolution of Taal volcano's hydrothermal system and its response to volcanic unrest. Long-term evolution of Main Crater Lake (MCL) composition shows a slow but consistent decrease of acidity, SO4, Mg, Fe and Al concentrations and a trend from light to heavy sulphate, consistent with a general decrease of volcanic gases dissolving in the hydrothermal system. Na, K and Cl concentrations remain constant indicating a non-volcanic origin for these elements. Sulphate and strontium isotopic data suggest this neutral chloride-rich component represents input of geothermal water into Taal hydrothermal system. A significant deviation from the long-term baseline can be seen in two samples from 1995. That year, pH dropped from 2.6 to 2.2, F, Si and Fe concentrations increased and Na, K and Cl concentrations decreased. Sulphate was depleted in 34S and temperature was 4 °C above baseline level at the time of sampling. We attribute these changes to the shallow intrusion of a degassing magma body during the unrest in 1991-1994. More recent unrest periods have not caused significant changes in the geochemistry of Taal hydrothermal waters and are therefore unlikely to have been triggered by shallow magma intrusion. A more likely cause for these events is thus pressurisation of the hydrothermal reservoir by increasing degassing from a stagnant magma reservoir. Our study indicates that new magmatic intrusions that might lead to the next eruption of Taal volcano are expected to change the geochemistry of MCL in the same way as in 1994-1995, with the most notable effects being changes in temperature, pH, F and Si concentrations.

The separated electric and magnetic field responses of luminescent bacteria exposed to pulsed microwave irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Catrin F., E-mail: williamscf@cardiff.ac.uk; School of Biosciences, Cardiff University, Main Building, Cathays Park, Cardiff, CF10 3AT Wales; Geroni, Gilles M.

Electromagnetic fields (EMFs) are ubiquitous in the digital world we inhabit, with microwave and millimetre wave sources of non-ionizing radiation employed extensively in electronics and communications, e.g., in mobile phones and Wi-Fi. Indeed, the advent of 5G systems and the “internet of things” is likely to lead to massive densification of wireless networks. Whilst the thermal effects of EMFs on biological systems are well characterised, their putative non-thermal effects remain a controversial subject. Here, we use the bioluminescent marine bacterium, Vibrio fischeri, to monitor the effects of pulsed microwave electromagnetic fields, of nominal frequency 2.5 GHz, on light emission. Separatedmore » electric and magnetic field effects were investigated using a resonant microwave cavity, within which the maxima of each field are separated. For pulsed electric field exposure, the bacteria gave reproducible responses and recovery in light emission. At the lowest pulsed duty cycle (1.25%) and after short durations (100 ms) of exposure to the electric field at power levels of 4.5 W rms, we observed an initial stimulation of bioluminescence, whereas successive microwave pulses became inhibitory. Much of this behaviour is due to thermal effects, as the bacterial light output is very sensitive to the local temperature. Conversely, magnetic field exposure gave no measurable short-term responses even at the highest power levels of 32 W rms. Thus, we were able to detect, de-convolute, and evaluate independently the effects of separated electric and magnetic fields on exposure of a luminescent biological system to microwave irradiation.« less

The separated electric and magnetic field responses of luminescent bacteria exposed to pulsed microwave irradiation

NASA Astrophysics Data System (ADS)

Williams, Catrin F.; Geroni, Gilles M.; Pirog, Antoine; Lloyd, David; Lees, Jonathan; Porch, Adrian

2016-08-01

Electromagnetic fields (EMFs) are ubiquitous in the digital world we inhabit, with microwave and millimetre wave sources of non-ionizing radiation employed extensively in electronics and communications, e.g., in mobile phones and Wi-Fi. Indeed, the advent of 5G systems and the "internet of things" is likely to lead to massive densification of wireless networks. Whilst the thermal effects of EMFs on biological systems are well characterised, their putative non-thermal effects remain a controversial subject. Here, we use the bioluminescent marine bacterium, Vibrio fischeri, to monitor the effects of pulsed microwave electromagnetic fields, of nominal frequency 2.5 GHz, on light emission. Separated electric and magnetic field effects were investigated using a resonant microwave cavity, within which the maxima of each field are separated. For pulsed electric field exposure, the bacteria gave reproducible responses and recovery in light emission. At the lowest pulsed duty cycle (1.25%) and after short durations (100 ms) of exposure to the electric field at power levels of 4.5 W rms, we observed an initial stimulation of bioluminescence, whereas successive microwave pulses became inhibitory. Much of this behaviour is due to thermal effects, as the bacterial light output is very sensitive to the local temperature. Conversely, magnetic field exposure gave no measurable short-term responses even at the highest power levels of 32 W rms. Thus, we were able to detect, de-convolute, and evaluate independently the effects of separated electric and magnetic fields on exposure of a luminescent biological system to microwave irradiation.

Engineering Geodesy - Definition and Core Competencies

NASA Astrophysics Data System (ADS)

Kuhlmann, Heiner; Schwieger, Volker; Wieser, Andreas; Niemeier, Wolfgang

2014-11-01

This article summarises discussions concerning the definition of "engineering geodesy" within the German Geodetic Commission. It is noted that engineering geodesy by means of its tasks, methods and characteristics is an application-oriented science whose research questions often arise from observed phenomena or from unsolved practical problems. In particular it is characterised by the professional handling of geometry-related problems in a cost-effective manner that includes comprehensive quality assessment at all phases of the problem solution - from planning through measurement to data processing and interpretation. The current methodical developments are primarily characterised by the increasing integration of the measurement and analysis into challenging construction, production and monitoring processes as well as by the transition to spatially continuous methods. A modern definition of engineering geodesy is proposed at the end of this article.

The endocannabinoid system and multiple sclerosis.

PubMed

Baker, David; Pryce, Gareth

2008-01-01

Multiple sclerosis (MS) is a neurodegenerative disease that is characterised by repeated inflammatory/demyelinating events within the central nervous system (CNS). In addition to relapsing-remitting neurological insults, leading to loss of function, patients are often left with residual, troublesome symptoms such as spasticity and pain. These greatly diminish "quality of life" and have prompted some patients to self-medicate with and perceive benefit from cannabis. Recent advances in cannabinoid biology are beginning to support these anecdotal observations, notably the demonstration that spasticity is tonically regulated by the endogenous cannabinoid system. Recent clinical trials may indeed suggest that cannabis has some potential to relieve, pain, spasms and spasticity in MS. However, because the CB(1) cannabinoid receptor mediates both the positive and adverse effects of cannabis, therapy will invariably be associated with some unwanted, psychoactive effects. In an experimental model of MS, and in MS tissue, there are local perturbations of the endocannabinoid system in lesional areas. Stimulation of endocannabinoid activity in these areas either through increase of synthesis or inhibition of endocannabinoid degradation offers the positive therapeutic potential of the cannabinoid system whilst limiting adverse events by locally targeting the lesion. In addition, CB(1) and CB(2) cannabinoid receptor stimulation may also have anti-inflammatory and neuroprotective potential as the endocannabinoid system controls the level of neurodegeneration that occurs as a result of the inflammatory insults. Therefore cannabinoids may not only offer symptom control but may also slow the neurodegenerative disease progression that ultimately leads to the accumulation of disability.

Exploiting Continuous Scanning Laser Doppler Vibrometry in timing belt dynamic characterisation

NASA Astrophysics Data System (ADS)

Chiariotti, P.; Martarelli, M.; Castellini, P.

2017-03-01

Dynamic behaviour of timing belts has always interested the engineering community over the years. Nowadays, there are several numerical methods to predict the dynamics of these systems. However, the tuning of such models by experimental approaches still represents an issue: an accurate characterisation does require a measurement in operating conditions since the belt mounting condition might severely affect its dynamic behaviour. Moreover, since the belt is constantly moving during running conditions, non-contact measurement methods are needed. Laser Doppler Vibrometry (LDV) and imaging techniques do represent valid candidates for this purpose. This paper aims at describing the use of Continuous Scanning LDV (CSLDV) as a tool for the dynamic characterisation of timing belts in IC (Internal Combustion) engines (cylinder head). The high-spatial resolution data that can be collected in short testing time makes CSLDV highly suitable for such application. The measurement on a moving surface, however, represents a challenge for CSLDV. The paper discusses how the belt in-plane speed influences CSLDV signal and how an order-based multi-harmonic excitation might affect the recovery of Operational Deflection Shapes in a CSLDV test. A comparison with a standard Discrete Scanning LDV measurement is also given in order to show that a CSLDV test, if well designed, can indeed provide the same amount of information in a drastically reduced amount of time.

Development of a Methodology for the Characterisation of Air-coupled Ultrasound Probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pietroni, Paolo; Marco Revel, Gian

2010-05-28

This study is aimed at developing a technique for the characterisation of air-coupled ultrasound probes, starting from the analysis of the mechanical behaviour of the probe membrane. The vibratory behaviour of the emission membrane is studied using laser-Doppler vibrometry techniques with high frequency demodulation system (20 MHz). The determination of the vibration provides information which are useful for the assessment of the performance of the probe, in particular concerning the Quality factor and the portion of the membrane which really contributes to the emission. During the second step the results of the vibration measurements are used to calculate, by meansmore » of numerical boundary element method, the ultrasound beam emitted in terms of intensity in space. The obtained field is compared with the direct measurements carried out by scanning with the receiver probe and a pinhole plate. This comparison allows the potential and the problems of the two different characterisation techniques to be determined, even if the pinhole technique (which is currently considered the state of the art) cannot be used as an absolute reference. This study appears to be useful for paving the way for a new methodology for the calibration of air-coupled ultrasound probes, which potentially could be used not only to improve the probe manufacturing process, but also to control conformity to specifications.« less

Wastewater characterisation by combining size fractionation, chemical composition and biodegradability.

PubMed

Ravndal, Kristin T; Opsahl, Eystein; Bagi, Andrea; Kommedal, Roald

2017-12-18

The potential for resource recovery from wastewater can be evaluated based on a detailed characterisation of wastewater. In this paper, results from fractionation and characterisation of two distinct wastewaters are reported. Using tangential flow filtration, the wastewater was fractionated into 10 size fractions ranging from 1 kDa to 1 mm, wherein the chemical composition and biodegradability were determined. Carbohydrates were dominant in particulate size fractions larger than 100 μm, indicating a potential of cellulose recovery from these fractions. While the particulate size fractions between 0.65 and 100 μm show a potential as a source for biofuel production due to an abundance of saturated C16 and C18 lipids. Both wastewaters were dominated by particulate (>0.65 μm), and oligo- and monomeric (<1 kDa) COD. Polymeric (1-1000 kDa) and colloidal (1000 kDa-0.65 μm) fractions had a low COD content, expected due to degradation in the sewer system upstream of the wastewater treatment plant. Biodegradation rates of particulate fractions increase with decreasing size. However, this was not seen in polymeric fractions where degradation rate was governed by chemical composition. Analytical validation of molecular weight and particle size distribution showed below filter cut-off retention of particles and polymers close to nominal cut-off, shifting the actual size distribution. Copyright © 2017. Published by Elsevier Ltd.

Ultrasonic sensor based defect detection and characterisation of ceramics.

PubMed

Kesharaju, Manasa; Nagarajah, Romesh; Zhang, Tonzhua; Crouch, Ian

2014-01-01

Ceramic tiles, used in body armour systems, are currently inspected visually offline using an X-ray technique that is both time consuming and very expensive. The aim of this research is to develop a methodology to detect, locate and classify various manufacturing defects in Reaction Sintered Silicon Carbide (RSSC) ceramic tiles, using an ultrasonic sensing technique. Defects such as free silicon, un-sintered silicon carbide material and conventional porosity are often difficult to detect using conventional X-radiography. An alternative inspection system was developed to detect defects in ceramic components using an Artificial Neural Network (ANN) based signal processing technique. The inspection methodology proposed focuses on pre-processing of signals, de-noising, wavelet decomposition, feature extraction and post-processing of the signals for classification purposes. This research contributes to developing an on-line inspection system that would be far more cost effective than present methods and, moreover, assist manufacturers in checking the location of high density areas, defects and enable real time quality control, including the implementation of accept/reject criteria. Copyright © 2013 Elsevier B.V. All rights reserved.

Random telegraph signal (RTS) noise and other anomalies in the near-infrared detector systems for the Euclid mission

NASA Astrophysics Data System (ADS)

Kohley, Ralf; Barbier, Rémi; Kubik, Bogna; Ferriol, Sylvain; Clemens, Jean-Claude; Ealet, Anne; Secroun, Aurélia; Conversi, Luca; Strada, Paolo

2016-08-01

Euclid is an ESA mission to map the geometry of the dark Universe with a planned launch date in 2020. Euclid is optimised for two primary cosmological probes, weak gravitational lensing and galaxy clustering. They are implemented through two science instruments on-board Euclid, a visible imager (VIS) and a near-infrared spectro-photometer (NISP), which are being developed and built by the Euclid Consortium instrument development teams. The NISP instrument contains a large focal plane assembly of 16 Teledyne HgCdTe H2RG detectors with 2.3μm cut-off wavelength and SIDECAR readout electronics. The performance of the detector systems is critical to the science return of the mission and extended on-ground tests are being performed for characterisation and calibration purposes. Special attention is given also to effects even on the scale of individual pixels, which are difficult to model and calibrate, and to identify any possible impact on science performance. This paper discusses a variety of undesired pixel behaviour including the known effect of random telegraph signal (RTS) noise based on initial on-ground test results from demonstrator model detector systems. Some stability aspects of the RTS pixel populations are addressed as well.

“Docs 'n Drugs” - A System for Case-Oriented and Web-based Training in Medicine

PubMed Central

Martens, A.; Bernauer, J.

1999-01-01

The tutoring process of conventional case-oriented medical training systems can be characterised as either guided or unguided. In contrast to that, the aim of the system “Docs'n Drugs” is to distinguish between different levels of guidance. The author can realise the tutoring case either as a guided, a half guided or a unguided tutoring process. The system architecture distinguishes between an authoring system and a tutoring system. Fundaments of these are the tutoring process model and the case-based knowledge model. This structure allows the reuse of elements of existing tutoring cases. The tutoring cases can be realised in German and English.

Integrating Technology, Pedagogy and Content in Mathematics Education

ERIC Educational Resources Information Center

Handal, Boris; Campbell, Chris; Cavanagh, Michael; Petocz, Peter; Kelly, Nick

2012-01-01

The need for appraising the effective integration of technologies into teaching and learning within a disciplinary context is crucial for upholding quality teaching standards in schools and formulating professional development programs. This paper describes the development and validation of an instrument aimed at characterising the integration of…

Tactile Behaviour of Greek Preschool Teachers

ERIC Educational Resources Information Center

Stamatis, Panagiotis J.; Kontakos, Anastasios Th.

2008-01-01

Introduction: The sense of touching is positively related to a number of environmental stimuli and forms an effective way of non verbal communication. More specifically, it can produce and transmit various personal experiences in the context of what we call "beneficial touching behaviours", which characterise the ongoing pedagogical…

Metabolite profiling of Listeria innocua for unravelling the inactivation mechanism of electrolysed water by nuclear magnetic resonance spectroscopy.

PubMed

Liu, Qin; Wu, Ji'en; Lim, Zhi Yang; Lai, Shaojuan; Lee, Norman; Yang, Hongshun

2018-04-20

Bactericidal effects of low concentration electrolysed water (LcEW) on microorganisms are previously well reported; however, the inactivation mechanism of EW is not understood. The lethal and sublethal injuries of L. monocytogenes and L. innocua by EW treatments were determined and the metabolic profile changes for L. innocua were characterised using nuclear magnetic resonance (NMR). Microbial metabolomics approach combined with multivariate data analyses was used to interpret the cellular chemical fingerprints of L. innocua. The relative amount of intracellular reactive oxygen species (ROS) was assayed using 2',7-dichlorodihydrofluorescein diacetate (H 2 DCFDA). The results showed that the proportion of the sublethally injured microbial cells L. monocytogenes and L. innocua increased from 40% to 70% and from 35% to 65%, respectively, when the free available chlorine (FAC) of LcEW increased from 2 to 8 mg/L. Overall, 36 low-molecular-weight metabolic compounds in L. innocua extracts were characterised by NMR spectroscopy. EW perturbation resulted in a drastic and multitude disruption across a wide range of biochemical process including peptidoglycan synthesis, nucleotides biosynthesis and amino acid metabolism. Elevated levels of α-ketoglutarate and succinate implicated the enhanced glutamate decarboxylase (GAD) system and γ-aminobutyric acid (GABA) shunt for the protection against oxidative stress. These findings provided the comprehensive insights into the metabolic response of Listeria to EW oxidative stress and can serve as a basis for better utilisation for sanitisation. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessing the depth of hypnosis of xenon anaesthesia with the EEG.

PubMed

Stuttmann, Ralph; Schultz, Arthur; Kneif, Thomas; Krauss, Terence; Schultz, Barbara

2010-04-01

Xenon was approved as an inhaled anaesthetic in Germany in 2005 and in other countries of the European Union in 2007. Owing to its low blood/gas partition coefficient, xenons effects on the central nervous system show a fast onset and offset and, even after long xenon anaesthetics, the wake-up times are very short. The aim of this study was to examine which electroencephalogram (EEG) stages are reached during xenon application and whether these stages can be identified by an automatic EEG classification. Therefore, EEG recordings were performed during xenon anaesthetics (EEG monitor: Narcotrend®). A total of 300 EEG epochs were assessed visually with regard to the EEG stages. These epochs were also classified automatically by the EEG monitor Narcotrend® using multivariate algorithms. There was a high correlation between visual and automatic classification (Spearman's rank correlation coefficient r=0.957, prediction probability Pk=0.949). Furthermore, it was observed that very deep stages of hypnosis were reached which are characterised by EEG activity in the low frequency range (delta waves). The burst suppression pattern was not seen. In deep hypnosis, in contrast to the xenon EEG, the propofol EEG was characterised by a marked superimposed higher frequency activity. To ensure an optimised dosage for the single patient, anaesthetic machines for xenon should be combined with EEG monitoring. To date, only a few anaesthetic machines for xenon are available. Because of the high price of xenon, new and further developments of machines focus on optimizing xenon consumption.

THE IMPACT OF KINSHIP NETWORKS ON OLD-AGE VULNERABILITY IN INDONESIA

PubMed Central

Schröder-Butterfill, Elisabeth

2007-01-01

SUMMARY This article examines the problem of care provision for elderly people in Java, a contemporary developing society characterised by lack of formal welfare services, nuclear family organisation and high levels of childlessness. A similar socio-demographic, cultural and economic regime existed in historical Northwest Europe, where it has been seen as having contributed to the early emergence of community based old-age care and low involvement of wider kin networks. Here the role of kin in providing old-age care in a nuclear family system is re-examined by drawing on longitudinal data of elderly people's life histories and support networks in a village in East Java. The central argument is that the identification of elders most vulnerable to a lack of care and support in old age requires understanding the nature and functioning of kin networks over time. The paper discusses three key aspects of networks—network membership, exchanges within networks and network dynamics—and arrives at a characterisation of different kin networks on the basis of size, composition, location and social status. By focusing on the effects of a specific crisis, namely the loss of a wife, on care outcomes in old age, it is possible to determine what kinds of kin networks are best able to adjust to a sudden change in older people's circumstances and protect them from declines in welfare. This reveals the importance, especially for childless elderly people, of extended, heterogeneous and well-connected kin networks. PMID:23750056

Current Advances in Developing Inhibitors of Bacterial Multidrug 
Efflux Pumps

PubMed Central

Mahmood, Hannah Y.; Jamshidi, Shirin; Sutton, J. Mark; Rahman, Khondaker M.

2016-01-01

Antimicrobial resistance represents a significant challenge to future healthcare provision. An acronym ESKAPEE has been derived from the names of the organisms recognised as the major threats although there are a number of other organisms, notably Neisseria gonorrhoeae, that have become equally challenging to treat in the clinic. These pathogens are characterised by the ability to rapidly develop and/or acquire resistance mechanisms in response to exposure to different antimicrobial agents. A key part of the armoury of these pathogens is a series of efflux pumps, which effectively exclude or reduce the intracellular concentration of a large number of antibiotics, making the pathogens significantly more resistant. These efflux pumps are the topic of considerable interest, both from the perspective of basic understanding of efflux pump function, and its role in drug resistance but also as targets for the development of novel adjunct therapies. The necessity to overcome antimicrobial resistance has encouraged investigations into the characterisation of resistance-modifying efflux pump inhibitors to block the mechanisms of drug extrusion, thereby restoring antibacterial susceptibility and returning existing antibiotics into the clinic. A greater understanding of drug recognition and transport by multidrug efflux pumps is needed to develop clinically useful inhibitors, given the breadth of molecules that can be effluxed by these systems. This review discusses different bacterial EPIs originating from both natural source and chemical synthesis and examines the challenges to designing successful EPIs that can be useful against multidrug resistant bacteria. PMID:26947776

Effects of realistic force feedback in a robotic assisted minimally invasive surgery system.

PubMed

Moradi Dalvand, Mohsen; Shirinzadeh, Bijan; Nahavandi, Saeid; Smith, Julian

2014-06-01

Robotic assisted minimally invasive surgery systems not only have the advantages of traditional laparoscopic procedures but also restore the surgeon's hand-eye coordination and improve the surgeon's precision by filtering hand tremors. Unfortunately, these benefits have come at the expense of the surgeon's ability to feel. Several research efforts have already attempted to restore this feature and study the effects of force feedback in robotic systems. The proposed methods and studies have some shortcomings. The main focus of this research is to overcome some of these limitations and to study the effects of force feedback in palpation in a more realistic fashion. A parallel robot assisted minimally invasive surgery system (PRAMiSS) with force feedback capabilities was employed to study the effects of realistic force feedback in palpation of artificial tissue samples. PRAMiSS is capable of actually measuring the tip/tissue interaction forces directly from the surgery site. Four sets of experiments using only vision feedback, only force feedback, simultaneous force and vision feedback and direct manipulation were conducted to evaluate the role of sensory feedback from sideways tip/tissue interaction forces with a scale factor of 100% in characterising tissues of varying stiffness. Twenty human subjects were involved in the experiments for at least 1440 trials. Friedman and Wilcoxon signed-rank tests were employed to statistically analyse the experimental results. Providing realistic force feedback in robotic assisted surgery systems improves the quality of tissue characterization procedures. Force feedback capability also increases the certainty of characterizing soft tissues compared with direct palpation using the lateral sides of index fingers. The force feedback capability can improve the quality of palpation and characterization of soft tissues of varying stiffness by restoring sense of touch in robotic assisted minimally invasive surgery operations.

Using a Laboratory Simulator in the Teaching and Study of Chemical Processes in Estuarine Systems

ERIC Educational Resources Information Center

Garcia-Luque, E.; Ortega, T.; Forja, J. M.; Gomez-Parra, A.

2004-01-01

The teaching of Chemical Oceanography in the Faculty of Marine and Environmental Sciences of the University of Cadiz (Spain) has been improved since 1994 by the employment of a device for the laboratory simulation of estuarine mixing processes and the characterisation of the chemical behaviour of many substances that pass through an estuary. The…

Developing Generic Competences in the European Higher Education Area: A Proposal for Teaching the Principles of Economics

ERIC Educational Resources Information Center

Velasco, Manuel Salas; Sanchez Martinez, Maria Teresa; Ferrero, Noelina Rodriguez

2012-01-01

The participation of Spain in the European Higher Education Area (EHEA) involves a number of important challenges for academics. Adapting to an educational model that is characterised by competence-based teaching is a difficult task, yet it is of paramount importance in the context of current reforms. In an educational system in which the…

Liberalisation and Privatisation of Higher Education in Flanders: Passing the Point of No Return? A Case Study

ERIC Educational Resources Information Center

Broucker, Bruno; De Wit, Kurt

2013-01-01

The higher education system in Flanders is characterised by tight regulation and a tradition of excluding private providers from the sector. However, as in other European countries, the Belgian public sector has been confronted with the principles of New Public Management (NPM) and trends of liberalisation and privatisation. The same goes for the…

Languages, Script and National Identity: Struggles over Linguistic Heterogeneity in Switzerland in the Nineteenth and Twentieth Centuries

ERIC Educational Resources Information Center

Boser, Lukas; Brühwiler, Ingrid

2017-01-01

For centuries, Switzerland has been a multilingual country (which currently has no less than four official languages.) Furthermore, one of those languages, German, is characterised by bigraphism (i.e. the coexistence of two different type styles). This article discusses the role played by language and writing systems in the great educational…