Status and future application of pilot lead-bismuth target circuit TC-1 for ADS

Energy Technology Data Exchange (ETDEWEB)

Ignatiev, S.; Leonchuk, M.; Orlov, Y.; Pankratov, D.; Reshetnikova, O.; Suvorov, G.; Zabudko, A. [Institute for Physics and Power Engineering, Obninsk (Russian Federation); Stepanov, V.; Klimov, N. [Experimental and Design Organization, Gidropress, Podolsk (Russian Federation); Hechanova, A.; Ma, J. [Nevada Univ., Las Vegas, NV (United States); Li, N. [Los Alamos National Lab., NM (United States); Gudowski, W. [International Science and Technology Center, Moscow (Russian Federation)

2007-07-01

A complicated evolution, status and future application of the pilot molten lead-bismuth target circuit of 1 MW proton beam power (TC-1) as an important part of a target-blanket accelerator driven system (ADS), that has been developed, created and twice tested under the auspice of the International Science and Technology Center (ISTC), is analyzed. The target complex TC-1 is a circulation lead-bismuth loop whose beam window is made of ferritic steel EP-823 (this steel was used in the past as material of fuel rods cladding in reactors cooled with lead-bismuth). At present TC-1 is operating at coolant temperature up to 300 C degrees and will be used to study different issues linked to the use of lead-bismuth: -) interaction with air, water and hydrogen, -) different regimes of flow, -) corrosion, -) filtering, or -) slag formation.

Cortical Surround Interactions and Perceptual Salience via Natural Scene Statistics.

Directory of Open Access Journals (Sweden)

Ruben Coen-Cagli

Full Text Available Spatial context in images induces perceptual phenomena associated with salience and modulates the responses of neurons in primary visual cortex (V1. However, the computational and ecological principles underlying contextual effects are incompletely understood. We introduce a model of natural images that includes grouping and segmentation of neighboring features based on their joint statistics, and we interpret the firing rates of V1 neurons as performing optimal recognition in this model. We show that this leads to a substantial generalization of divisive normalization, a computation that is ubiquitous in many neural areas and systems. A main novelty in our model is that the influence of the context on a target stimulus is determined by their degree of statistical dependence. We optimized the parameters of the model on natural image patches, and then simulated neural and perceptual responses on stimuli used in classical experiments. The model reproduces some rich and complex response patterns observed in V1, such as the contrast dependence, orientation tuning and spatial asymmetry of surround suppression, while also allowing for surround facilitation under conditions of weak stimulation. It also mimics the perceptual salience produced by simple displays, and leads to readily testable predictions. Our results provide a principled account of orientation-based contextual modulation in early vision and its sensitivity to the homogeneity and spatial arrangement of inputs, and lends statistical support to the theory that V1 computes visual salience.

The importance of surrounding tissues and window settings for contouring of moving targets

Energy Technology Data Exchange (ETDEWEB)

Borm, Kai Joachim [Technische Universitaet Muenchen, Medical School, Munich (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany); Oechsner, Markus; Berndt, Johannes; Combs, Stephanie Elisabeth; Molls, Michael; Duma, Marciana Nona [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany)

2015-09-15

The aim of the study was to assess the importance of surrounding tissues for the delineation of moving targets in tissue-specific phantoms and to find optimal settings for lung, soft tissue, and liver tumors. Tumor movement was simulated by a water-filled table tennis ball (target volume, TV). Three phantoms were created: corkboards to simulate lung tissue (lung phantom, LunPh), animal fat as fatty soft tissue (fatty tissue phantom, FatPh), and water enhanced with contrast medium as the liver tissue (liver phantom, LivPh). Slow planning three-dimensional compute tomography images (3D-CTs) were acquired with and without phantom movements. One-dimensional tumor movement (1D), three-dimensional tumor movement (3D), as well as a real patient's tumor trajectories were simulated. The TV was contoured using two lung window settings, two soft-tissue window settings, and one liver window setting. The volumes were compared to mathematical calculated values. TVs were underestimated in all phantoms due to movement. The use of soft-tissue windows in the LivPh led to a significantunderestimation of the TV (70.8 % of calculated TV). When common window settings [LunPh + 200 HU/-1,000 HU (upper window/lower window threshold); FatPh: + 240 HU/-120 HU; LivPh: + 175 HU/+ 50 HU] were used, the contoured TVs were: LivPh, 84.0 %; LunPh, 93.2 %, and FatPh, 92.8 %. The lower window threshold had a significant impact on the size of the delineated TV, whereas changes of the upper threshold led only to small differences. The decisive factor for window settings is the lower window threshold (for adequate TV delineation in the lung and fatty-soft tissue it should be lower than density values of surrounding tissue). The use of a liver window should be considered. (orig.) [German] Das Ziel dieser Arbeit war es, den Einfluss des umgebenden Gewebes auf die Konturierung bewegter Objekte zu untersuchen. Um die optimalen CT-Fensterungen fuer Lungen-, Weichteil- und Lebertumoren zu bestimmen

Reduced visual surround suppression in schizophrenia shown by measuring contrast detection thresholds

Directory of Open Access Journals (Sweden)

Ignacio eSerrano-Pedraza

2014-12-01

Full Text Available Visual perception in schizophrenia is attracting a broad interest given the deep knowledge that we have about the visual system in healthy population. In visual science it is known that the visibility of a grating located in the visual periphery is impaired by the presence of a surrounding grating of the same spatial frequency and orientation. Previous studies have suggested abnormal visual surround suppression in patients with schizophrenia. Given that schizophrenia patients have cortical alterations including hypofunction of NMDA receptors and reduced concentration of GABA neurotransmitter, which affect lateral inhibitory connections, then they should perform better than controls in visual suppression tasks. We tested this hypothesis by measuring contrast detection thresholds using a new stimulus configuration. We tested two groups: 21 schizophrenia patients and 24 healthy subjects. Thresholds were obtained using Bayesian staircases in a 4AFC detection task where the target was a grating within a 3 deg Butterworth window that appeared in one of four possible positions at 5 deg eccentricity. We compared three conditions, a target with no surround (NS, b target on top of a surrounding grating of 20 deg diameter and 25% contrast with same spatial frequency and orthogonal orientation (OS, and c target on top of a surrounding grating with parallel (same orientation (PS. Our results show significantly lower thresholds for controls than for patients in NS and OS conditions. We also found significant lower suppression ratios PS/NS in patients. Our results support the hypothesis that inhibitory lateral connections in early visual cortex are impaired in schizophrenia patients.

Neutron production from 158 GeV/c per nucleon lead ions on thin copper and lead targets in the angular range 30-135 deg

CERN Document Server

Agosteo, S; Foglio-Para, A; Gini, L; Mitaroff, W A; Silari, Marco; Ulrici, L

2002-01-01

The neutron emission from 5, 10 and 20 mm thick lead and 10 and 20 mm thick copper targets bombarded by a lead ion beam with momentum of 158 GeV/c per nucleon were measured at the CERN Super Proton Synchrotron. The neutron yield and spectral fluence per incident ion on target were measured with an extended range Bonner sphere spectrometer in the angular range 30-135 deg. with respect to beam direction. Monte Carlo simulations with the FLUKA code were performed to establish a guess spectrum for the unfolding of the experimental data. The results have shown that, lacking Monte Carlo radiation transport codes dealing with ions with masses larger than 1 amu, a reasonable prediction can be carried out by scaling the result of a Monte Carlo calculation for protons by the projectile mass number to the power of 0.85-0.95 for a lead target and 0.88-1.03 for a copper target.

MicroRNA-target gene responses to lead-induced stress in cotton (Gossypium hirsutum L.).

Science.gov (United States)

He, Qiuling; Zhu, Shuijin; Zhang, Baohong

2014-09-01

MicroRNAs (miRNAs) play key roles in plant responses to various metal stresses. To investigate the miRNA-mediated plant response to heavy metals, cotton (Gossypium hirsutum L.), the most important fiber crop in the world, was exposed to different concentrations (0, 25, 50, 100, and 200 µM) of lead (Pb) and then the toxicological effects were investigated. The expression patterns of 16 stress-responsive miRNAs and 10 target genes were monitored in cotton leaves and roots by quantitative real-time PCR (qRT-PCR); of these selected genes, several miRNAs and their target genes are involved in root development. The results show a reciprocal regulation of cotton response to lead stress by miRNAs. The characterization of the miRNAs and the associated target genes in response to lead exposure would help in defining the potential roles of miRNAs in plant adaptation to heavy metal stress and further understanding miRNA regulation in response to abiotic stress.

Lead contamination in soil and vegetation of areas surrounding ...

African Journals Online (AJOL)

H

2012-09-25

Sep 25, 2012 ... mine, Tarz lead mine, Shahid Bahonar Copper Industries Company (CSP), Industrial zone No.1 and ... world-wide, mining remains one of the main sources of heavy metal pollution. ..... 24-26 November Bangkok, Thailand.

Lead contamination in soil and vegetation of areas surrounding ...

African Journals Online (AJOL)

The results show significant negative correlation between waste pH and Pb in industrial waste, plant and soil. Also the results show that Acantholimon sp. and Astragalus glancanthus were dominant plant in two mines upon floristic quantities assay. Lead concentration was 15.8 mg/kg DW and 1.61 mg/kg DW in Ghanat ...

MEGAPIE analytical support task : characterization of lead-bismuth eutectic and sodium-cooled tungsten target materials for accelerator driven systems

International Nuclear Information System (INIS)

Gohar, Y.

2002-01-01

Lead-Bismuth Eutectic and Tungsten are under consideration as target materials with high-energy protons for generating neutrons to drive actinide and fission product transmuters. A detailed characterization has been performed to study the performance of these target materials as a function of the main variables and the design selections. The characterization includes the neutron yield, the spatial energy deposition, the neutron spectrum, the beam window performance, and the target buffer impact on the target performance. The characterization has also considered high-energy deuteron particles to study the impact on the target neutronic performance. The obtained results quantify the performance of the Lead-Bismuth Eutectic and Tungsten target materials as a function of the target variables and design selections

A role for fragment-based drug design in developing novel lead compounds for central nervous system targets

Directory of Open Access Journals (Sweden)

Michael J. Wasko

2015-09-01

Full Text Available Hundreds of millions of U.S. dollars are invested in the research and development of a single drug. Lead compound development is an area ripe for new design strategies. Therapeutic lead candidates have been traditionally found using high-throughput in vitro pharmacologic screening, a costly method for assaying thousands of compounds. This approach has recently been augmented by virtual screening, which employs computer models of the target protein to narrow the search for possible leads. A variant of virtual screening is fragment-based drug design, an emerging in silico lead discovery method that introduces low molecular weight fragments, rather than intact compounds, into the binding pocket of the receptor model. These fragments serve as starting points for growing the lead candidate. Current efforts in virtual fragment-based drug design within central nervous system (CNS targets are reviewed, as is a recent rule-based optimization strategy in which new molecules are generated within a 3D receptor binding pocket using the fragment as a scaffold. This process places special emphasis on creating synthesizable molecules but also exposes computational questions worth addressing. Fragment-based methods provide a viable, relatively low-cost alternative for therapeutic lead discovery and optimization that can be applied to CNS targets to augment current design strategies.

A Role for Fragment-Based Drug Design in Developing Novel Lead Compounds for Central Nervous System Targets.

Science.gov (United States)

Wasko, Michael J; Pellegrene, Kendy A; Madura, Jeffry D; Surratt, Christopher K

2015-01-01

Hundreds of millions of U.S. dollars are invested in the research and development of a single drug. Lead compound development is an area ripe for new design strategies. Therapeutic lead candidates have been traditionally found using high-throughput in vitro pharmacological screening, a costly method for assaying thousands of compounds. This approach has recently been augmented by virtual screening (VS), which employs computer models of the target protein to narrow the search for possible leads. A variant of VS is fragment-based drug design (FBDD), an emerging in silico lead discovery method that introduces low-molecular weight fragments, rather than intact compounds, into the binding pocket of the receptor model. These fragments serve as starting points for "growing" the lead candidate. Current efforts in virtual FBDD within central nervous system (CNS) targets are reviewed, as is a recent rule-based optimization strategy in which new molecules are generated within a 3D receptor-binding pocket using the fragment as a scaffold. This process not only places special emphasis on creating synthesizable molecules but also exposes computational questions worth addressing. Fragment-based methods provide a viable, relatively low-cost alternative for therapeutic lead discovery and optimization that can be applied to CNS targets to augment current design strategies.

Targeting Alzheimer's disease by investigating previously unexplored chemical space surrounding the cholinesterase inhibitor donepezil

CSIR Research Space (South Africa)

Van Greunen, DG

2017-02-01

Full Text Available A series of twenty seven acetylcholinesterase inhibitors, as potential agents for the treatment of Alzheimer's disease, were designed and synthesised based upon previously unexplored chemical space surrounding the molecular skeleton of the drug...

Identification of β-SiC surrounded by relatable surrounding diamond ...

Indian Academy of Sciences (India)

β-SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman ... Change in the nature of the surrounding material structure and its .... intensity implies very low graphite content in thin film. In.

Neutron production in lead targets by high-energy light-mass heavy ions

International Nuclear Information System (INIS)

Daniehl', A.V.; Lyapin, V.S.; Tsvetkov, I.O.

1992-01-01

The characteristics of the time-of-flight spectrometer and the double different distributions of neutrons and secondary charged particles produced by 2 GeV protons and 1 GeVXA d,α, 6 Li and 12 C ions bombarding lead targets are described. Experimental data are compared with the results of calculations by codes SITHA. 17 refs.; 10 figs.; 1 tab

Elemental Technologies for Lead-Bismuth Spallation Target System in J-PARC

International Nuclear Information System (INIS)

Obayashi, H.; Yamaguchi, K.; Saito, S.; Sugawara, T.; Takei, H.; Sasa, T.

2015-01-01

Japan Atomic Energy Agency (JAEA) has been researching and developing an Accelerator-Driven System (ADS) as a dedicated system for the transmutation of long-lived radioactive nuclides. The ADS proposed by JAEA uses the lead-bismuth eutectic (LBE) alloy as a spallation target material and a coolant. In the various R and D for ADS, construction of the Transmutation Experimental Facility (TEF) is planned under the framework of the J-PARC project as a preceding step before the construction of demonstrative ADS. In this R and D, TEF is considered for the experimental investigation of the feasibility of the beam window, the structural materials, and to investigate the operation properties of the target system by using 400 MeV-250 kW proton beam. This target system is consisted of various elements and must be able to operate without troubles during an operation period of TEF facility. Furthermore, in the maintenance period after the operation, because the inside of a hot cell storing a target is exposed to strong radiations, all elements must be designed as remote control devices. In this study, the present conditions of the design and the result of performance test of each important elements were confirmed in the realisation of the LBE target system, such as the monitoring system of flow rate by using the ultrasonic method, the heater system with the metallic heat insulator joined to a flow channel of LBE, and the operability of remote handing. (authors)

Scheduling rules to achieve lead-time targets in outpatient appointment systems

OpenAIRE

Sivakumar, Appa Iyer; Nguyen, Thu Ba Thi; Graves, Stephen C

2015-01-01

This paper considers how to schedule appointments for outpatients, for a clinic that is subject to appointment lead-time targets for both new and returning patients. We develop heuristic rules, which are the exact and relaxed appointment scheduling rules, to schedule each new patient appointment (only) in light of uncertainty about future arrivals. The scheduling rules entail two decisions. First, the rules need to determine whether or not a patient's request can be accepted; then, if the req...

Proton-beam window design for a transmutation facility operating with a liquid lead target

Energy Technology Data Exchange (ETDEWEB)

Jansen, C.; Lypsch, F.; Lizana, P. [Institute for Safety Research and Reactor Technology, Juelich (Germany)] [and others

1995-10-01

The proton beam target of an accelerator-driven transmutation facility can be designed as a vertical liquid lead column. To prevent lead vapor from entering the accelerator vacuum, a proton-beam window has to separate the area above the lead surface from the accelerator tube. Two radiation-cooled design alternatives have been investigated which should withstand a proton beam of 1.6 GeV and 25 mA. Temperature calculations based on energy deposition calculations with the Monte Carlo code HETC, stability analysis and spallation-induced damage calculations have been performed showing the applicability of both designs.

Neutron yield from thick lead target by the action of high-energy electrons

International Nuclear Information System (INIS)

Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.; Sorokin, P.V.

1978-01-01

The results are presented of studying the complete neutron yield from a lead target bombarded by high-energy electrons. Neutrons were recorded by the method of radio-active indicators. The dependence of the neutron yield on the target thickness varying from 0.2 to 8 cm was obtained at the energies of electrons of 230 and 1200 MeV. The neutron yield for the given energies with the target of 6 cm in thickness is in the range of saturation and is 0.1 +-0.03 and 0.65+-0.22 (neutr./MeV.el.), respectively. The neutron angular distributions were measured for different thicknesses of targets at the 201, 230 and 1200 MeV electrons. Within the error limits the angular distributions are isotropic. The dependence of neutron yield on the electron energy was examined for a 3 cm thick target. In the energy range of 100-1200 MeV these values are related by a linear dependence with the proportionality coefficient C=3x10 -4 (neutr./MeV.el.)

Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

Directory of Open Access Journals (Sweden)

Anna A. Kosovicheva

2012-09-01

Full Text Available Acetylcholine (ACh reduces the spatial spread of excitatory fMRI responses in early visual cortex and the receptive field sizes of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two tasks that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Exp. 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: 1 surround grating with the same orientation as the center (parallel, 2 surround orthogonal to the center, or 3 no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS. Cholinergic enhancement reduced thresholds only in the parallel condition, thereby reducing OSSS. In Exp. 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the target and flanking letters that allowed reliable identification. Cholinergic enhancement had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early visual cortical

Challenges Surrounding the Injection and Arrival of Targets at LIFE Fusion Chamber Center

Energy Technology Data Exchange (ETDEWEB)

Miles, R; Spaeth, M; Manes, K; Amendt, P; Tabak, M; Bond, T; Kucheyev, S; Latkowski, J; Loosmore, G; Bliss, E; Baker, K; Bhandarkar, S; Petzoldt, R; Alexander, N; Tillack, M; Holdener, D

2010-12-01

IFE target designers must consider several engineering requirements in addition to the physics requirements for successful target implosion. These considerations include low target cost, high manufacturing throughput, the ability of the target to survive the injection into the fusion chamber and arrive in a condition and physical position consistent with proper laser-target interaction and ease of post-implosion debris removal. This article briefly describes these considerations for the Laser Inertial Fusion-based Energy (LIFE) targets currently being designed.

Measurements of gas and volatile element production rates from an irradiated molten lead and lead-bismuth spallation target with proton beams of 1 and 1.4 GeV

International Nuclear Information System (INIS)

Tall, Y.

2008-03-01

The integrated project EUROTRANS (European Research Programme for the Transmutation of High Level Nuclear Waste in an Accelerator Driven System) of the 6. EURATOM Framework Programme aims to demonstrate the transmutation of radioactive waste in ADS (Accelerator Driven Sub-critical system). It will carry out a first advanced design of an experimental facility to demonstrate the technical feasibility of transmutation, and will produce a conceptual design of an industrial facility dedicated to transmutation. An ADS consists of three fundamental elements: the accelerator of protons, the sub-critical core and the spallation target. SUBATECH (physique Sub-Atomique et des Technologies associees) laboratory is involved to the study of the chosen liquid lead-bismuth as a spallation ADS target. The irradiation of liquid lead-bismuth target with energetic proton beam generates in addition to neutrons, volatile and radioactive residues. In order to determine experimentally the production rates of gas and volatile elements following a spallation reaction in a lead-bismuth target, the experiment IS419 was performed at the ISOLDE facility at CERN (Centre Europeen de la Recherche Nucleaire). This experiment constitutes the frame of the thesis whose main objective is to assess and study the production and release rates of many gas and volatile element from the irradiated lead-bismuth target with an energetic proton beam. The obtained data are compared to Monte Carlo simulation code (MCNPX) results in order to test the intranuclear cascade model of Bertini and of Cugnon, and the evaporation options of Dresner and Schmidt. (author)

40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...

Science.gov (United States)

2010-07-01

... of experience in a related field (e.g., lead, asbestos, environmental remediation work, or... at least 3 years of experience in a related field (e.g., lead, asbestos, environmental remediation... engaged in lead-based paint activities: target housing and child-occupied facilities. 745.226 Section 745...

The surrounding concrete structure of the containment as a safety component

International Nuclear Information System (INIS)

Alex, H.; Kuntze, W.M.

1978-01-01

This paper will briefly discuss the containments of the various types of reactors in the Federal Republic of Germany and will try to show the importance of the surrounding concrete structures with respect to safety. It will be seen that the surrounding concrete structures serve in any case - as protection against external events - as secondary shielding and must therefore be considered as a passive safety feature. The design requirements for the surrounding concrete structures with respect to protection against external events and to physical protection generally supplement each other. Reference will be made to possible alternatives, which might result from studies of underground siting of nuclear power plants. Whether or not this type of construction can lead to additional safety can only be judged when the results of all these studies - some of which are still under way - are evaluated. The concluding part of this paper will deal with the responsibilities of the civil engineering supervisory authorities and the nuclear licensing authorities with respect to the surrounding concrete structures. (orig.) [de

In Situ Observation of Hard Surrounding Rock Displacement at 2400-m-Deep Tunnels

Science.gov (United States)

Feng, Xia-Ting; Yao, Zhi-Bin; Li, Shao-Jun; Wu, Shi-Yong; Yang, Cheng-Xiang; Guo, Hao-Sen; Zhong, Shan

2018-03-01

This paper presents the results of in situ investigation of the internal displacement of hard surrounding rock masses within deep tunnels at China's Jinping Underground Laboratory Phase II. The displacement evolution of the surrounding rock during the entire excavation processes was monitored continuously using pre-installed continuous-recording multi-point extensometers. The evolution of excavation-damaged zones and fractures in rock masses were also observed using acoustic velocity testing and digital borehole cameras, respectively. The results show four kinds of displacement behaviours of the hard surrounding rock masses during the excavation process. The displacement in the inner region of the surrounding rock was found to be greater than that of the rock masses near the tunnel's side walls in some excavation stages. This leads to a multi-modal distribution characteristic of internal displacement for hard surrounding rock masses within deep tunnels. A further analysis of the evolution information on the damages and fractures inside the surrounding rock masses reveals the effects of excavation disturbances and local geological conditions. This recognition can be used as the reference for excavation and supporting design and stability evaluations of hard-rock tunnels under high-stress conditions.

Consistent and robust determination of border ownership based on asymmetric surrounding contrast.

Science.gov (United States)

Sakai, Ko; Nishimura, Haruka; Shimizu, Ryohei; Kondo, Keiichi

2012-09-01

Determination of the figure region in an image is a fundamental step toward surface construction, shape coding, and object representation. Localized, asymmetric surround modulation, reported neurophysiologically in early-to-intermediate-level visual areas, has been proposed as a mechanism for figure-ground segregation. We investigated, computationally, whether such surround modulation is capable of yielding consistent and robust determination of figure side for various stimuli. Our surround modulation model showed a surprisingly high consistency among pseudorandom block stimuli, with greater consistency for stimuli that yielded higher accuracy of, and shorter reaction times in, human perception. Our analyses revealed that the localized, asymmetric organization of surrounds is crucial in the detection of the contrast imbalance that leads to the determination of the direction of figure with respect to the border. The model also exhibited robustness for gray-scaled natural images, with a mean correct rate of 67%, which was similar to that of figure-side determination in human perception through a small window and of machine-vision algorithms based on local processing. These results suggest a crucial role of surround modulation in the local processing of figure-ground segregation. Copyright © 2012 Elsevier Ltd. All rights reserved.

On the use of lead/tin alloys as target material for the production of spallation neutrons

International Nuclear Information System (INIS)

Atchison, F.; Baumann, P.; Brys, T.; Daum, M.; Egorov, A.; Fierlinger, P.; Fuchs, P.; Henneck, R.; Joray, St.; Keil, R.; Kirch, K.; Krutova, R.; Kuehne, G.; Lebedev, V.T.; Obermeier, H.; Orlova, D.N.; Perret, Ch.; Pichlmaier, A.; Richard, Ph.; Serebrov, A.; Thies, S.

2005-01-01

We have examined the suitability of lead (Pb)/tin (Sn) alloys with atomic ratios between 4:1 and 12:1 for use as a spallation target material for the PSI spallation ultracold neutron source. The measured corrosion rate with distilled water, R c -5 cm/year, is more than a factor of 80, less than for normal Pb; this corrosion rate is satisfactory. Microscopic investigations of the surface after the exposure to water revealed no visual changes. Small angle neutron scattering showed that the alloy is mechanically stable under thermal cycling. An experimental simulation of a water-cooled spallation neutron target made of Pb/Sn pebbles with a filling factor of 60% was investigated; the pulsed proton beam was simulated using hot and cold water in the target 'cooling' circuit. With realistic operational parameters for the cooling circuit, serious deformation of the PbSn pebbles occurred which finally blocked the cooling circuit. The Pb/Sn alloys solve the corrosion problem but its mechanical properties are inadequate leading to too short a lifetime to be practical in the PSI spallation source

Naturally Inspired Peptide Leads: Alanine Scanning Reveals an Actin-Targeting Thiazole Analogue of Bisebromoamide.

Science.gov (United States)

Johnston, Heather J; Boys, Sarah K; Makda, Ashraff; Carragher, Neil O; Hulme, Alison N

2016-09-02

Systematic alanine scanning of the linear peptide bisebromoamide (BBA), isolated from a marine cyanobacterium, was enabled by solid-phase peptide synthesis of thiazole analogues. The analogues have comparable cytotoxicity (nanomolar) to that of BBA, and cellular morphology assays indicated that they target the actin cytoskeleton. Pathway inhibition in human colon tumour (HCT116) cells was explored by reverse phase protein array (RPPA) analysis, which showed a dose-dependent response in IRS-1 expression. Alanine scanning reveals a structural dependence to the cytotoxicity, actin targeting and pathway inhibition, and allows a new readily synthesised lead to be proposed. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Effectively Communicating the Uncertainties Surrounding Ebola Virus Transmission.

Directory of Open Access Journals (Sweden)

Andy Kilianski

2015-10-01

Full Text Available The current Ebola virus outbreak has highlighted the uncertainties surrounding many aspects of Ebola virus virology, including routes of transmission. The scientific community played a leading role during the outbreak-potentially, the largest of its kind-as many of the questions surrounding ebolaviruses have only been interrogated in the laboratory. Scientists provided an invaluable resource for clinicians, public health officials, policy makers, and the lay public in understanding the progress of Ebola virus disease and the continuing outbreak. Not all of the scientific communication, however, was accurate or effective. There were multiple instances of published articles during the height of the outbreak containing potentially misleading scientific language that spurred media overreaction and potentially jeopardized preparedness and policy decisions at critical points. Here, we use articles declaring the potential for airborne transmission of Ebola virus as a case study in the inaccurate reporting of basic science, and we provide recommendations for improving the communication about unknown aspects of disease during public health crises.

Effectively Communicating the Uncertainties Surrounding Ebola Virus Transmission.

Science.gov (United States)

Kilianski, Andy; Evans, Nicholas G

2015-10-01

The current Ebola virus outbreak has highlighted the uncertainties surrounding many aspects of Ebola virus virology, including routes of transmission. The scientific community played a leading role during the outbreak-potentially, the largest of its kind-as many of the questions surrounding ebolaviruses have only been interrogated in the laboratory. Scientists provided an invaluable resource for clinicians, public health officials, policy makers, and the lay public in understanding the progress of Ebola virus disease and the continuing outbreak. Not all of the scientific communication, however, was accurate or effective. There were multiple instances of published articles during the height of the outbreak containing potentially misleading scientific language that spurred media overreaction and potentially jeopardized preparedness and policy decisions at critical points. Here, we use articles declaring the potential for airborne transmission of Ebola virus as a case study in the inaccurate reporting of basic science, and we provide recommendations for improving the communication about unknown aspects of disease during public health crises.

Do surrounding figures' emotions affect judgment of the target figure's emotion? Comparing the eye-movement patterns of European Canadians, Asian Canadians, Asian international students, and Japanese.

Science.gov (United States)

Masuda, Takahiko; Wang, Huaitang; Ishii, Keiko; Ito, Kenichi

2012-01-01

Although the effect of context on cognition is observable across cultures, preliminary findings suggest that when asked to judge the emotion of a target model's facial expression, East Asians are more likely than their North American counterparts to be influenced by the facial expressions of surrounding others (Masuda et al., 2008b). Cultural psychologists discuss this cultural variation in affective emotional context under the rubric of holistic vs. analytic thought, independent vs. interdependent self-construals, and socially disengaged vs. socially engaged emotion (e.g., Mesquita and Markus, 2004). We demonstrate that this effect is generalizable even when (1) photos of real facial emotions are used, (2) the saliency of the target model's emotion is attenuated, and (3) a specific amount of observation time is allocated. We further demonstrate that the experience plays an important role in producing cultural variations in the affective context effect on cognition.

Measurement of the Neutron Component in a Shower Generated in a Lead Target by Relativistic Nuclear Beam

International Nuclear Information System (INIS)

Chultehm, D.; Damdinsurehn, Ts.; D'yachenko, V.M.; Ehnkhzhin, L.; Lomova, L.A.; Perelygin, V.P.; Tolstov, K.D.

1994-01-01

The present paper describes a method of determining the total number of neutrons generated in an extended lead target by relativistic nuclei and protons. It is shown that 101±20 neutrons per proton are produced in the target with the volume of 50x50x80 cm 3 at 3.65 GeV energy of protons. 11 refs., 14 figs., 1 tab

Dual-acting of Hybrid Compounds - A New Dawn in the Discovery of Multi-target Drugs: Lead Generation Approaches.

Science.gov (United States)

Abdolmaleki, Azizeh; Ghasemi, Jahan B

2017-01-01

Finding high quality beginning compounds is a critical job at the start of the lead generation stage for multi-target drug discovery (MTDD). Designing hybrid compounds as selective multitarget chemical entity is a challenge, opportunity, and new idea to better act against specific multiple targets. One hybrid molecule is formed by two (or more) pharmacophore group's participation. So, these new compounds often exhibit two or more activities going about as multi-target drugs (mtdrugs) and may have superior safety or efficacy. Application of integrating a range of information and sophisticated new in silico, bioinformatics, structural biology, pharmacogenomics methods may be useful to discover/design, and synthesis of the new hybrid molecules. In this regard, many rational and screening approaches have followed by medicinal chemists for the lead generation in MTDD. Here, we review some popular lead generation approaches that have been used for designing multiple ligands (DMLs). This paper focuses on dual- acting chemical entities that incorporate a part of two drugs or bioactive compounds to compose hybrid molecules. Also, it presents some of key concepts and limitations/strengths of lead generation methods by comparing combination framework method with screening approaches. Besides, a number of examples to represent applications of hybrid molecules in the drug discovery are included. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Methods of Assessing Noise Nuisance of Real Estate Surroundings

Directory of Open Access Journals (Sweden)

Szopińska Kinga

2016-03-01

Full Text Available Testing what factors create the market value of real estate is key information when preparing property valuations as well as other opinions and professional evaluations on the basis of which court verdicts or administrative decisions are made. One of the factors influencing the value of some real estate is the level of noise present in the surroundings, which can lead to the occurrence of noise nuisance negatively affecting social relations.

Comparison of Deep Brain Stimulation Lead Targeting Accuracy and Procedure Duration between 1.5- and 3-Tesla Interventional Magnetic Resonance Imaging Systems: An Initial 12-Month Experience.

Science.gov (United States)

Southwell, Derek G; Narvid, Jared A; Martin, Alastair J; Qasim, Salman E; Starr, Philip A; Larson, Paul S

2016-01-01

Interventional magnetic resonance imaging (iMRI) allows deep brain stimulator lead placement under general anesthesia. While the accuracy of lead targeting has been described for iMRI systems utilizing 1.5-tesla magnets, a similar assessment of 3-tesla iMRI procedures has not been performed. To compare targeting accuracy, the number of lead targeting attempts, and surgical duration between procedures performed on 1.5- and 3-tesla iMRI systems. Radial targeting error, the number of targeting attempts, and procedure duration were compared between surgeries performed on 1.5- and 3-tesla iMRI systems (SmartFrame and ClearPoint systems). During the first year of operation of each system, 26 consecutive leads were implanted using the 1.5-tesla system, and 23 consecutive leads were implanted using the 3-tesla system. There was no significant difference in radial error (Mann-Whitney test, p = 0.26), number of lead placements that required multiple targeting attempts (Fisher's exact test, p = 0.59), or bilateral procedure durations between surgeries performed with the two systems (p = 0.15). Accurate DBS lead targeting can be achieved with iMRI systems utilizing either 1.5- or 3-tesla magnets. The use of a 3-tesla magnet, however, offers improved visualization of the target structures and allows comparable accuracy and efficiency of placement at the selected targets. © 2016 S. Karger AG, Basel.

The relation between residential property and its surroundings and day- and night-time residential burglary

NARCIS (Netherlands)

Montoya, Lorena; Junger, Marianne; Ongena, Yfke

This article examines how residential property and its surroundings influence day- and night-time residential burglary. Crime Prevention Through Environmental Design (CPTED) principles of territoriality, surveillance, access control, target hardening, image maintenance, and activity support underpin

The Relation Between Residential Property and its Surroundings and Day- and Night-Time Residential Burglary

NARCIS (Netherlands)

Montoya, L.; Junger, Marianne; Ongena, Yfke

This article examines how residential property and its surroundings influence day- and night-time residential burglary. Crime Prevention Through Environmental Design (CPTED) principles of territoriality, surveillance, access control, target hardening, image maintenance, and activity support underpin

A cylindrical multiwire high-pressure gas proportional chamber surrounding a gaseous $_{2} target with a mylar separation foil $6 \\mu m thick

CERN Document Server

Gastaldi, Ugo; Averdung, H; Bailey, J; Beer, G A; Dreher, B; Erdman, K L; Klempt, E; Merle, K; Neubecker, K; Sabev, C; Schwenk, H; Wendling, R D; White, B L; Wodrich, R

1978-01-01

The characteristics and performances of a cylindrical multiwire proportional chamber built and used at CERN in experiment S142 for the study of the pp atom spectroscopy are presented. The chamber surrounds a high-pressure gaseous H/sub 2/ target, from which it is separated by a very thin window (6 mu m mylar foil). The active volume (90 cm long; 2 cm thick, internal diameter=30 cm) is divided into 36 equal and independent cells each covering 10 degrees in azimuth. At 4 abs. atm the detection efficiency for X-rays is higher than 20% in the whole energy range 1.5-15 keV. Typical resolutions are 35% fwhm for the 3 ke V Ar fluorescence line and 25% fwhm for the 5.5 keV /sup 54/Mn line. Working pressures from 0.5 to 16 abs. atm have been used. (8 refs).

Evaluating the effect of the space surrounding the condenser of a household refrigerator

Energy Technology Data Exchange (ETDEWEB)

Bassiouny, Ramadan [Dept. of Mech. Power Eng. and Energy, Faculty of Engineering, Minia University, Minia 61111 (Egypt)

2009-11-15

The paper presents an analytical and computational modeling of the effect of the space surrounding the condenser of a household refrigerator on the rejected heat. The driving force for rejecting the heat carried by the refrigerant from the interior of a refrigerator is the temperature difference between the condenser outer surface and surrounding air. The variation of this difference, because of having an insufficient space, increasing the room air temperature, or blocking this space, is of interest to quantify its effect The results showed that having an enough surrounding space width (s > 200 mm) leads to a decrease in the temperature of the air flowing vertically around the condenser coil. Accordingly, this would significantly increase the amount of heat rejected. Moreover, blocking this space retards the buoyant flow up the condenser surface, and hence increases the air temperature around the condenser. This would also decrease the heat rejected from the condenser. Predicted temperature contours are displayed to visualize the air plumes' variation surrounding the condenser in all cases. (author)

Smart Surroundings

NARCIS (Netherlands)

Havinga, Paul J.M.; Jansen, P.G.; Lijding, M.E.M.; Scholten, Johan

2004-01-01

Ambient systems are networked embedded systems integrated with everyday environments and supporting people in their activities. These systems will create a Smart Surrounding for people to facilitate and enrich daily life and increase productivity at work. Such systems will be quite different from

Perceptual Color Space Representations in the Oculomotor System Are Modulated by Surround Suppression and Biased Selection

OpenAIRE

Kehoe, Devin H.; Rahimi, Maryam; Fallah, Mazyar

2018-01-01

The oculomotor system utilizes color extensively for planning saccades. Therefore, we examined how the oculomotor system actually encodes color and several factors that modulate these representations: attention-based surround suppression and inherent biases in selecting and encoding color categories. We measured saccade trajectories while human participants performed a memory-guided saccade task with color targets and distractors and examined whether oculomotor target selection processing was...

Analysis of the geomorphology surrounding the Chang'e-3 landing site

Science.gov (United States)

Li, Chun-Lai; Mu, Ling-Li; Zou, Xiao-Duan; Liu, Jian-Jun; Ren, Xin; Zeng, Xing-Guo; Yang, Yi-Man; Zhang, Zhou-Bin; Liu, Yu-Xuan; Zuo, Wei; Li, Han

2014-12-01

Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surface environment. To better understand the environment of this region, this paper utilizes the available high-resolution topography data, image data and geological data to carry out a detailed analysis and research on the area surrounding the landing site (Sinus Iridum and 45 km×70 km of the landing area) as well as on the topography, landform, geology and lunar dust of the area surrounding the landing site. A general topographic analysis of the surrounding area is based on a digital elevation model and digital elevation model data acquired by Chang'e-2 that have high resolution; the geology analysis is based on lunar geological data published by USGS; the study on topographic factors and distribution of craters and rocks in the surrounding area covering 4 km×4 km or even smaller is based on images from the CE-3 landing camera and images from the topographic camera; an analysis is done of the effect of the CE-3 engine plume on the lunar surface by comparing images before and after the landing using data from the landing camera. A comprehensive analysis of the results shows that the landing site and its surrounding area are identified as typical lunar mare with flat topography. They are suitable for maneuvers by the rover, and are rich in geological phenomena and scientific targets, making it an ideal site for exploration.

Do Surrounding Figures’ Emotions Affect Judgment of the Target Figure’s Emotion? Comparing the Eye-Movement Patterns of European Canadians, Asian Canadians, Asian International Students, and Japanese

Directory of Open Access Journals (Sweden)

Taka eMasuda

2012-09-01

Full Text Available Although the effect of context on cognition is observable across cultures, preliminary findings suggest that when asked to judge the emotion of a target model’s facial expression, East Asians are more likely than their North American counterparts to be influenced by the facial expressions of surrounding others (Masuda, Ellsworth, Mesquita, Leu, Tanida, & van de Veerdonk, 2008. Cultural psychologists discuss this cultural variation in affective emotional context under the rubric of holistic vs. analytic thought, independent vs. interdependent self-construals, and socially disengaged vs. socially engaged emotion (e.g., Mesquita & Markus, 2004. We demonstrate that this effect is generalizable even when (a photos of real facial emotions are used, (b the saliency of the target model’s emotion is attenuated, and (c a specific amount of observation time is allocated. We further demonstrate that the socialization factor plays an important role in producing cultural variations in the affective context effect on cognition.

Determining tissue-lead levels in large game mammals harvested with lead bullets: human health concerns.

Science.gov (United States)

Tsuji, L J S; Wainman, B C; Jayasinghe, R K; VanSpronsen, E P; Liberda, E N

2009-04-01

Recently, the use of lead isotope ratios has definitively identified lead ammunition as a source of lead exposure for First Nations people, but the isotope ratios for lead pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden; however, few studies have determined if lead bullet fragments are present in big game carcasses. We found elevated tissue-lead concentrations (up to 5,726.0 microg/g ww) in liver (5/9) and muscle (6/7) samples of big game harvested with lead bullets and radiographic evidence of lead fragments. Thus, we would advise that the tissue surrounding the wound channel be removed and discarded, as this tissue may be contaminated by lead bullet fragments.

Introduction to the ultrasound targeted microbubble destruction technique.

Science.gov (United States)

Walton, Chad B; Anderson, Cynthia D; Boulay, Rachel; Shohet, Ralph V

2011-06-12

In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid microbubble contrast agents. In mice these vector-carrying microbubbles can be administered intravenously or directly to the left ventricle of the heart. In larger animals they can also be infused through an intracoronary catheter. The subsequent delivery from the circulation to a target organ occurs by acoustic cavitation at a resonant frequency of the microbubbles. It seems likely that the mechanical energy generated by the microbubble destruction results in transient pore formation in or between the endothelial cells of the microvasculature of the targeted region. As a result of this sonoporation effect, the transfection efficiency into and across the endothelial cells is enhanced, and transgene-encoding vectors are deposited into the surrounding tissue. Plasmid DNA remaining in the circulation is rapidly degraded by nucleases in the blood, which further reduces the likelihood of delivery to non-sonicated tissues and leads to highly specific target-organ transfection.

NMR approaches in structure-based lead discovery: recent developments and new frontiers for targeting multi-protein complexes.

Science.gov (United States)

Dias, David M; Ciulli, Alessio

2014-01-01

Nuclear magnetic resonance (NMR) spectroscopy is a pivotal method for structure-based and fragment-based lead discovery because it is one of the most robust techniques to provide information on protein structure, dynamics and interaction at an atomic level in solution. Nowadays, in most ligand screening cascades, NMR-based methods are applied to identify and structurally validate small molecule binding. These can be high-throughput and are often used synergistically with other biophysical assays. Here, we describe current state-of-the-art in the portfolio of available NMR-based experiments that are used to aid early-stage lead discovery. We then focus on multi-protein complexes as targets and how NMR spectroscopy allows studying of interactions within the high molecular weight assemblies that make up a vast fraction of the yet untargeted proteome. Finally, we give our perspective on how currently available methods could build an improved strategy for drug discovery against such challenging targets. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Analysis of the geomorphology surrounding the Chang'e-3 landing site

International Nuclear Information System (INIS)

Li Chun-Lai; Mu Ling-Li; Zou Xiao-Duan; Liu Jian-Jun; Ren Xin; Zeng Xing-Guo; Yang Yi-Man; Zhang Zhou-Bin; Liu Yu-Xuan; Zuo Wei; Li Han

2014-01-01

Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surface environment. To better understand the environment of this region, this paper utilizes the available high-resolution topography data, image data and geological data to carry out a detailed analysis and research on the area surrounding the landing site (Sinus Iridum and 45 km×70 km of the landing area) as well as on the topography, landform, geology and lunar dust of the area surrounding the landing site. A general topographic analysis of the surrounding area is based on a digital elevation model and digital elevation model data acquired by Chang'e-2 that have high resolution; the geology analysis is based on lunar geological data published by USGS; the study on topographic factors and distribution of craters and rocks in the surrounding area covering 4 km×4 km or even smaller is based on images from the CE-3 landing camera and images from the topographic camera; an analysis is done of the effect of the CE-3 engine plume on the lunar surface by comparing images before and after the landing using data from the landing camera. A comprehensive analysis of the results shows that the landing site and its surrounding area are identified as typical lunar mare with flat topography. They are suitable for maneuvers by the rover, and are rich in geological phenomena and scientific targets, making it an ideal site for exploration

Topical report on a preconceptual design for the Spallation-Induced Lithium Conversion (SILC) target for the accelerator production of tritium (APT)

International Nuclear Information System (INIS)

Van Tuyle, G.J.; Cokinos, D.M.; Czajkowski, C.; Franz, E.M.; Kroeger, P.; Todosow, M.; Youngblood, R.; Zucker, M.

1993-01-01

The preconceptual design of the APT Li-Al target system, also referred to as the Spallation-Induced Lithium Conversion (SILC), target system, is summarized in this report. The system has been designed to produce a ''3/8 Goal'' quantity of tritium using the 200-mA, 1.0 GeV proton beam emerging from the LANL-designed LINAC. The SILC target system consists of a beam expander, a heavy-water-cooled lead spallation neutron source assembly surrounded by light-water-cooled Li-Al blankets, a target window, heat removal systems, and related safety systems. The preconceptual design of each of these major components is described. Descriptions are also provided for the target fabrication, tritium extraction, and waste-steam processes. Performance characteristics are presented and discussed

Topical report on a preconceptual design for the Spallation-Induced Lithium Conversion (SILC) target for the accelerator production of tritium (APT)

Energy Technology Data Exchange (ETDEWEB)

Van Tuyle, G.J.; Cokinos, D.M.; Czajkowski, C.; Franz, E.M.; Kroeger, P.; Todosow, M.; Youngblood, R.; Zucker, M.

1993-09-30

The preconceptual design of the APT Li-Al target system, also referred to as the Spallation-Induced Lithium Conversion (SILC), target system, is summarized in this report. The system has been designed to produce a ``3/8 Goal`` quantity of tritium using the 200-mA, 1.0 GeV proton beam emerging from the LANL-designed LINAC. The SILC target system consists of a beam expander, a heavy-water-cooled lead spallation neutron source assembly surrounded by light-water-cooled Li-Al blankets, a target window, heat removal systems, and related safety systems. The preconceptual design of each of these major components is described. Descriptions are also provided for the target fabrication, tritium extraction, and waste-steam processes. Performance characteristics are presented and discussed.

Fragile X and autism: Intertwined at the molecular level leading to targeted treatments

Directory of Open Access Journals (Sweden)

Hagerman Randi

2010-09-01

Full Text Available Abstract Fragile X syndrome (FXS is caused by an expanded CGG repeat (> 200 repeats in the 5' untranslated portion of the fragile mental retardation 1 gene (FMR1, leading to deficiency or absence of the FMR1 protein (FMRP. FMRP is an RNA carrier protein that controls the translation of several other genes that regulate synaptic development and plasticity. Autism occurs in approximately 30% of FXS cases, and pervasive developmental disorder, not otherwise specified (PDD-NOS occurs in an additional 30% of cases. Premutation repeat expansions (55 to 200 CGG repeats may also give rise to autism spectrum disorders (ASD, including both autism and PDD-NOS, through a different molecular mechanism that involves a direct toxic effect of the expanded CGG repeat FMR1 mRNA. RNA toxicity can also lead to aging effects including tremor, ataxia and cognitive decline, termed fragile X-associated tremor ataxia syndrome (FXTAS, in premutation carriers in late life. In studies of mice bearing premutation expansions, there is evidence of early postnatal neuronal cell toxicity, presenting as reduced cell longevity, decreased dendritic arborization and altered synaptic morphology. There is also evidence of mitochondrial dysfunction in premutation carriers. Many of the problems with cellular dysregulation in both premutation and full mutation neurons also parallel the cellular abnormalities that have been documented in autism without fragile X mutations. Research regarding dysregulation of neurotransmitter systems in FXS, including the metabotropic glutamate receptor (mGluR1/5 pathway and γ aminobutyric acid (GABAA pathways, have led to new targeted treatments for FXS. Preliminary evidence suggests that these new targeted treatments will also be beneficial in non-fragile X forms of autism.

Improved spatial targeting with directionally segmented deep brain stimulation leads for treating essential tremor

Science.gov (United States)

Keane, Maureen; Deyo, Steve; Abosch, Aviva; Bajwa, Jawad A.; Johnson, Matthew D.

2012-08-01

Deep brain stimulation (DBS) in the ventral intermediate nucleus of thalamus (Vim) is known to exert a therapeutic effect on postural and kinetic tremor in patients with essential tremor (ET). For DBS leads implanted near the caudal border of Vim, however, there is an increased likelihood that one will also induce paresthesia side-effects by stimulating neurons within the sensory pathway of the ventral caudal (Vc) nucleus of thalamus. The aim of this computational study was to (1) investigate the neuronal pathways modulated by therapeutic, sub-therapeutic and paresthesia-inducing DBS settings in three patients with ET and (2) determine how much better an outcome could have been achieved had these patients been implanted with a DBS lead containing directionally segmented electrodes (dDBS). Multi-compartment neuron models of the thalamocortical, cerebellothalamic and medial lemniscal pathways were first simulated in the context of patient-specific anatomies, lead placements and programming parameters from three ET patients who had been implanted with Medtronic 3389 DBS leads. The models showed that in these patients, complete suppression of tremor was associated most closely with activating an average of 62% of the cerebellothalamic afferent input into Vim (n = 10), while persistent paresthesias were associated with activating 35% of the medial lemniscal tract input into Vc thalamus (n = 12). The dDBS lead design demonstrated superior targeting of the cerebello-thalamo-cortical pathway, especially in cases of misaligned DBS leads. Given the close proximity of Vim to Vc thalamus, the models suggest that dDBS will enable clinicians to more effectively sculpt current through and around thalamus in order to achieve a more consistent therapeutic effect without inducing side-effects.

Measurement of neutron energy spectra of PuO[sub 2]-UO[sub 2] mixed oxide fuel and penetrated through surrounding lead-acryl shield

Energy Technology Data Exchange (ETDEWEB)

Nakao, Noriaki; Tsujimura, Norio; Nakamura, Takashi (Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center); Momose, Takumaro; Ninomiya, Kazushige; Ishiguro; Hideharu

1993-12-01

The energy spectra of neutrons emitted from an aluminum can containing PuO[sub 2]-UO[sub 2] mixed oxide fuel and penetrated through a 35mm thick lead-acryl shield surrounding the can, were measured with the NE-213 organic liquid scintillator, the proton recoil proportional counter and the multi-moderator [sup 3]He spectrometer (Bonner Ball). The measured results were compared with the results calculated by the MORSE-CG Monte Carlo code on the basis of source neutron yields obtained by the ORIGEN-2 code and the source energy spectrum cited from the reference data. The agreement between these two was pretty good. The dose equivalents were then calculated from thus-obtained energy spectra and the flux-to-dose conversion factor and showed good agreement with the data measured with the neutron dose-equivalent counters (rem counters). Since the published data on energy spectrum of mixed oxide fuel are very scarce, these results can be useful as basic data for shielding design study and radiation control of nuclear fuel facilities. (author).

3D Room Visualization on Android Based Mobile Device (with Philips™’ Surround Sound Music Player

Directory of Open Access Journals (Sweden)

Durio Etgar

2012-12-01

Full Text Available This project’s specifically purposed as a demo application, so anyone can get the experience of a surround audio room without having to physically involved to it, with a main idea of generating a 3D surround sound room scenery coupled with surround sound in a handier package, namely, a “Virtual Listen Room”. Virtual Listen Room set a foundation of an innovative visualization that later will be developed and released as one of way of portable advertisement. This application was built inside of Android environment. Android device had been chosen as the implementation target, since it leaves massive development spaces and mostly contains essential components needed on this project, including graphic processor unit (GPU.  Graphic manipulation can be done using an embedded programming interface called OpenGL ES, which is planted in all Android devices generally. Further, Android has a Accelerometer Sensor that is needed to be coupled with scene to produce a dynamic movement of the camera. Surround sound effect can be reached with a decoder from Phillips called MPEG Surround Sound Decoder. To sum the whole project, we got an application with sensor-dynamic 3D room visualization coupled with Philips’ Surround Sound Music Player. We can manipulate several room’s properties; Subwoofer location, Room light, and how many speakers inside it, the application itself works well despite facing several performance problems before, later to be solved. [Keywords : Android,Visualization,Open GL; ES; 3D; Surround Sensor

Radiation shielding lead shield

International Nuclear Information System (INIS)

Dei, Shoichi.

1991-01-01

The present invention concerns lead shields for radiation shielding. Shield boxes are disposed so as to surround a pipeline through which radioactive liquids, mists or like other objects are passed. Flanges are formed to each of the end edges of the shield boxes and the shield boxes are connected to each other by the flanges. Upon installation, empty shield boxes not charged with lead particles and iron plate shields are secured at first at the periphery of the pipeline. Then, lead particles are charged into the shield boxes. This attains a state as if lead plate corresponding to the depth of the box is disposed. Accordingly, operations for installation, dismantling and restoration can be conducted in an empty state with reduced weight to facilitate the operations. (I.S.)

Targeting the tumor microenvironment

Energy Technology Data Exchange (ETDEWEB)

Kenny, P.A.; Lee, G.Y.; Bissell, M.J.

2006-11-07

Despite some notable successes cancer remains, for the most part, a seemingly intractable problem. There is, however, a growing appreciation that targeting the tumor epithelium in isolation is not sufficient as there is an intricate mutually sustaining synergy between the tumor epithelial cells and their surrounding stroma. As the details of this dialogue emerge, new therapeutic targets have been proposed. The FDA has already approved drugs targeting microenvironmental components such as VEGF and aromatase and many more agents are in the pipeline. In this article, we describe some of the 'druggable' targets and processes within the tumor microenvironment and review the approaches being taken to disrupt these interactions.

EXPERIMENTAL STUDY ON THE STABILITY OF SURROUNDING ROCK IN TUNNEL BLASTING CONSTRUCTION

Directory of Open Access Journals (Sweden)

Hongxian Fu

2018-04-01

Full Text Available In this study, criteria and blasting technologies are introduced in order to control the stability of surrounding rock of tunnel built using drill-and-blast safety. The paper is composed of three parts, namely, a blast vibration propagation law in roof surrounding rock in close proximity to tunnel face, two formulae to calculate particle critical vibration velocity of shotcrete and key structural element at the roof of tunnel, and innovative technologies of tunnel blasting. The blast vibration propagation law is the base to control the stability of surrounding rock during tunnel blasting. Based on Morhr-Coulomb criterion and the dynamic analysis, two formulae to calculate the critical particle vibration velocity are proposed. Based on a series of trial blasts using electronic detonators, two innovative blasting technologies are derived. One is the blast holes detonated one by one by using electronic detonator, and another is the blast holes detonated by combining initiation system of electronic detonators and nonel detonators. The use of electronic detonators in tunnel blasting not only leads to a smaller blast vibration but also to a smaller extent of the EDZ (excavation damaged zone.

Potential containment materials for liquid-lead and lead-bismuth eutectic spallation neutron source

International Nuclear Information System (INIS)

Park, J.J.; Butt, D.P.; Beard, C.A.

1997-11-01

Lead (Pb) and lead-bismuth eutectic (44Pb-56Bi) have been the two primary candidate liquid-metal target materials for the production of spallation neutrons. Selection of a container material for the liquid-metal target will greatly affect the lifetime and safety of the target subsystem. For the lead target, niobium-1 (wt%) zirconium (Nb-1Zr) is a candidate containment material for liquid lead, but its poor oxidation resistance has been a major concern. The oxidation rate of Nb-1Zr was studied based on the calculations of thickness loss due to oxidation. According to these calculations, it appeared that uncoated Nb-1Zr may be used for a one-year operation at 900 C at P O 2 = 1 x 10 -6 torr, but the same material may not be used in argon with 5-ppm oxygen. Coating technologies to reduce the oxidation of Nb-1Zr are reviewed, as are other candidate refractory metals such as molybdenum, tantalum, and tungsten. For the Pb-Bi target, three candidate containment materials are suggested based on a literature survey of the materials compatibility and proton irradiation tests: Croloy 2-1/4, modified 9Cr-1Mo, and 12Cr-1Mo (HT-9) steel. These materials seem to be used only if the lead-bismuth is thoroughly deoxidized and treated with zirconium and magnesium

Fragmentation cross sections of relativistic 8436Kr and 10947Ag nuclei in targets from hydrogen to lead

International Nuclear Information System (INIS)

Nilsen, B.S.; Waddington, C.J.; Cummings, J.R.; Garrard, T.L.; Klarmann, J.

1995-01-01

With the addition of krypton and silver projectiles we have extended our previous studies of the fragmentation of heavy relativistic nuclei in targets ranging in mass from hydrogen to lead. These projectiles were studied at a number of discrete energies between 450 and 1500A MeV. The total and partial charge-changing cross sections were determined for each energy, target, and projectile, and the values compared with previous predictions. A new parametrization of the dependence of the total charge-changing cross sections on the target and projectile is introduced, based on nuclear charge radii derived from electron scattering. We have also parametrized the energy dependence of the total cross sections over the range of energies studied. New parameters were found for a previous representation of the partial charge-changing cross sections in hydrogen and a new parametrization has been introduced for the nonhydrogen targets. The evidence that limiting fragmentation has been attained for these relatively light projectile nuclei at Bevalac energies is shown to be inconclusive, and further measurements at higher energies will be needed to address this question

3D Room Visualization on Android Based Mobile Device (with Philips™’ Surround Sound Music Player

Directory of Open Access Journals (Sweden)

Durio Etgar

2013-01-01

Full Text Available This project’s specifically purposed as a demo application, so anyone can get the experience of a surround audio room without having to physically involved to it, with a main idea of generating a 3D surround sound room scenery coupled with surround sound in a handier package, namely, a “Virtual Listen Room”. Virtual Listen Room set a foundation of an innovative visualization that later will be developed and released as one of way of portable advertisement. This application was built inside of Android environment. Android device had been chosen as the implementation target, since it leaves massive development spaces and mostly contains essential components needed on this project, including graphic processor unit (GPU. Graphic manipulation can be done using an embedded programming interface called OpenGL ES, which is planted in all Android devices generally. Further, Android has a Accelerometer Sensor that is needed to be coupled with scene to produce a dynamic movement of the camera. Surround sound effect can be reached with a decoder from Phillips called MPEG Surround Sound Decoder. To sum the whole project, we got an application with sensor-dynamic 3D room visualization coupled with Philips’ Surround Sound Music Player. We can manipulate several room’s properties; Subwoofer location, Room light, and how many speakers inside it, the application itself works well despite facing several performance problems before, later to be solved.

Changes in unique hues induced by chromatic surrounds.

Science.gov (United States)

Klauke, Susanne; Wachtler, Thomas

2016-03-01

A chromatic surround can have a strong influence on the perceived hue of a stimulus. We investigated whether chromatic induction has similar effects on the perception of colors that appear pure and unmixed (unique red, green, blue, and yellow) as on other colors. Subjects performed unique hue settings of stimuli in isoluminant surrounds of different chromaticities. Compared with the settings in a neutral gray surround, unique hue settings altered systematically with chromatic surrounds. The amount of induced hue shift depended on the difference between stimulus and surround hues, and was similar for unique hue settings as for settings of nonunique hues. Intraindividual variability in unique hue settings was roughly twice as high as for settings obtained in asymmetric matching experiments, which may reflect the presence of a reference stimulus in the matching task. Variabilities were also larger with chromatic surrounds than with neutral gray surrounds, for both unique hue settings and matching of nonunique hues. The results suggest that the neural representations underlying unique hue percepts are influenced by the same neural processing mechanisms as the percepts of other colors.

Lead-Bismuth Eutectic cooled experimental Accelerator Driven System. Windowless target unit thermal-hydraulic analysis

International Nuclear Information System (INIS)

Bianchi, F.; Ferri, R.; Moreau, V.

2004-01-01

A main concern related to the peaceful use of nuclear energy is the safe management of nuclear wastes, with particular attention to long-lived fission products. An increasing attention has recently been addressed to transmutation systems (Accelerator Driven System: ADS) able to 'burn' the actinides and some of the long-lived fission products (High-Level Waste: HLW), transforming them in short or medium-lived wastes that may be easier managed and stored in the geological disposal, with the consequent easier acceptability by population. An ADS consists of a subcritical-core coupled with an accelerator by means of a target. This paper deals with the thermal-hydraulic analysis, performed with STAR-CD and RELAP5 codes for the windowless target unit of Lead-Bismuth Eutectic (LBE) cooled experimental ADS (XADS), both to assess its behaviour during operational and accident sequences and to provide input data for the thermal-mechanical analyses. It also reports a description of modifications properly implemented in the codes used for the assessment of this kind of plants. (author)

A potential target for organophosphate insecticides leading to spermatotoxicity.

Science.gov (United States)

Suzuki, Himiko; Tomizawa, Motohiro; Ito, Yuki; Abe, Keisuke; Noro, Yuki; Kamijima, Michihiro

2013-10-16

Organophosphate (OP) insecticides as an anticholinesterase also act on the diverse serine hydrolase targets, thereby revealing secondary or unexpected toxic effects including male reproductive toxicity. The present investigation detects a possible target molecule(s) for OP-induced spermatotoxicity (sperm deformity, underdevelopment, and reduced motility) from a chemical standpoint. The activity-based protein profiling (ABPP) approach with a phosphonofluoridate fluorescent probe pinpointed the molecular target for fenitrothion (FNT, a major OP insecticide) oxon (bioactive metabolite of FNT) in the mouse testicular membrane proteome, i.e., FNT oxon phosphorylates the fatty acid amide hydrolase (FAAH), which plays pivotal roles in spermatogenesis and sperm motility acquirement. Subsequently, mice were treated orally with vehicle or FNT for 10 days, and FAAH activity in testis or epididymis cauda was markedly reduced by the subacute exposure. ABPP analysis revealed that FAAH was selectively inhibited among the FNT-treated testicular membrane proteome. Accordingly, FAAH is a potential target for OP-elicited spermatotoxicity.

Electrophysiological evidence for the action of a center-surround mechanism on semantic processing in the left hemisphere

Directory of Open Access Journals (Sweden)

Diana eDeacon

2013-12-01

Full Text Available Physiological evidence was sought for a center-surround attentional mechanism (CSM, which has been proposed to assist in the retrieval of weakly activated items from semantic memory. The CSM operates by facilitating strongly related items in the center of the weakly activated area of semantic memory, and inhibiting less strongly related items in its surround. In this study weak activation was created by having subjects acquire the meanings of new words to a recall criterion of only 50%. Subjects who attained this approximate criterion level of performance were subsequently included in a semantic priming task, during which ERPs were recorded. Primes were newly learned rare words, and targets were either synonyms, nonsynonymously related words, or unrelated words. All stimuli were presented to the RVF/LH (right visual field/left hemisphere or the LVF/RH (left visual field/right hemisphere. Under RVF/LH stimulation the newly learned word primes produced facilitation on N400 for synonym targets, and inhibition for related targets. No differences were observed under LVF/RH stimulation. The LH thus, supports a CSM, whereby a synonym in the center of attention focused on the newly learned word is facilitated, whereas a related word in the surround is inhibited. The data are consistent with the view of this laboratory that semantic memory is subserved by a spreading activation system in the LH. Also consistent with our view, there was no evidence of spreading activation in the RH. The findings are discussed in the context of additional recent theories of semantic memory. Finally, the adult right hemisphere may require more learning than the LH in order to demonstrate evidence of meaning acquisition.

Next-to leading order analysis of target mass corrections to structure functions and asymmetries

International Nuclear Information System (INIS)

Brady, L.T.; Accardi, A.; Hobbs, T.J.; Melnitchouk, W.

2011-01-01

We perform a comprehensive analysis of target mass corrections (TMCs) to spin-averaged structure functions and asymmetries at next-to-leading order. Several different prescriptions for TMCs are considered, including the operator product expansion, and various approximations to it, collinear factorization, and xi-scaling. We assess the impact of each of these on a number of observables, such as the neutron to proton F 2 structure function ratio, and parity-violating electron scattering asymmetries for protons and deuterons which are sensitive to gamma-Z interference effects. The corrections from higher order radiative and nuclear effects on the parity-violating deuteron asymmetry are also quantified.

Perceptual Color Space Representations in the Oculomotor System Are Modulated by Surround Suppression and Biased Selection

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Devin H. Kehoe

2018-01-01

Full Text Available The oculomotor system utilizes color extensively for planning saccades. Therefore, we examined how the oculomotor system actually encodes color and several factors that modulate these representations: attention-based surround suppression and inherent biases in selecting and encoding color categories. We measured saccade trajectories while human participants performed a memory-guided saccade task with color targets and distractors and examined whether oculomotor target selection processing was functionally related to the CIE (x,y color space distances between color stimuli and whether there were hierarchical differences between color categories in the strength and speed of encoding potential saccade goals. We observed that saccade planning was modulated by the CIE (x,y distances between stimuli thus demonstrating that color is encoded in perceptual color space by the oculomotor system. Furthermore, these representations were modulated by (1 cueing attention to a particular color thereby eliciting surround suppression in oculomotor color space and (2 inherent selection and encoding biases based on color category independent of cueing and perceptual discriminability. Since surround suppression emerges from recurrent feedback attenuation of sensory projections, observing oculomotor surround suppression suggested that oculomotor encoding of behavioral relevance results from integrating sensory and cognitive signals that are pre-attenuated based on task demands and that the oculomotor system therefore does not functionally contribute to this process. Second, although perceptual discriminability did partially account for oculomotor processing differences between color categories, we also observed preferential processing of the red color category across various behavioral metrics. This is consistent with numerous previous studies and could not be simply explained by perceptual discriminability. Since we utilized a memory-guided saccade task, this

Perceptual Color Space Representations in the Oculomotor System Are Modulated by Surround Suppression and Biased Selection.

Science.gov (United States)

Kehoe, Devin H; Rahimi, Maryam; Fallah, Mazyar

2018-01-01

The oculomotor system utilizes color extensively for planning saccades. Therefore, we examined how the oculomotor system actually encodes color and several factors that modulate these representations: attention-based surround suppression and inherent biases in selecting and encoding color categories. We measured saccade trajectories while human participants performed a memory-guided saccade task with color targets and distractors and examined whether oculomotor target selection processing was functionally related to the CIE ( x , y ) color space distances between color stimuli and whether there were hierarchical differences between color categories in the strength and speed of encoding potential saccade goals. We observed that saccade planning was modulated by the CIE ( x , y ) distances between stimuli thus demonstrating that color is encoded in perceptual color space by the oculomotor system. Furthermore, these representations were modulated by (1) cueing attention to a particular color thereby eliciting surround suppression in oculomotor color space and (2) inherent selection and encoding biases based on color category independent of cueing and perceptual discriminability. Since surround suppression emerges from recurrent feedback attenuation of sensory projections, observing oculomotor surround suppression suggested that oculomotor encoding of behavioral relevance results from integrating sensory and cognitive signals that are pre-attenuated based on task demands and that the oculomotor system therefore does not functionally contribute to this process. Second, although perceptual discriminability did partially account for oculomotor processing differences between color categories, we also observed preferential processing of the red color category across various behavioral metrics. This is consistent with numerous previous studies and could not be simply explained by perceptual discriminability. Since we utilized a memory-guided saccade task, this indicates that

Blacklisting and the ban: contesting targeted sanctions in Europe

NARCIS (Netherlands)

de Goede, M.

2011-01-01

This article examines the practice of targeted sanctions as they are deployed against individuals and groups suspected of financing and facilitating terrorism in Europe. Substantial academic attention and critique has surrounded targeted sanctions and blacklists, as these practices challenge

Process for manufacture of inertial confinement fusion targets and resulting product

International Nuclear Information System (INIS)

Solomon, D.E.; Wise, K.D.; Wuttke, G.H.; Masnari, N.A.; Rensel, W.B.; Robinson, M.G.

1980-01-01

A method of manufacturing inertial confinement fusion targets is described which is adaptable for high volume production of low cost targets in a wide variety of sizes. The targets include a spherical pellet of fusion fuel surrounded by a protective concentric shell. (UK)

Gas cooled leads

International Nuclear Information System (INIS)

Shutt, R.P.; Rehak, M.L.; Hornik, K.E.

1993-01-01

The intent of this paper is to cover as completely as possible and in sufficient detail the topics relevant to lead design. The first part identifies the problems associated with lead design, states the mathematical formulation, and shows the results of numerical and analytical solutions. The second part presents the results of a parametric study whose object is to determine the best choice for cooling method, material, and geometry. These findings axe applied in a third part to the design of high-current leads whose end temperatures are determined from the surrounding equipment. It is found that cooling method or improved heat transfer are not critical once good heat exchange is established. The range 5 5 but extends over a large of values. Mass flow needed to prevent thermal runaway varies linearly with current above a given threshold. Below that value, the mass flow is constant with current. Transient analysis shows no evidence of hysteresis. If cooling is interrupted, the mass flow needed to restore the lead to its initially cooled state grows exponentially with the time that the lead was left without cooling

Power reactors and sub-critical blanket systems with lead and lead-bismuth as coolant and/or target material. Utilization and transmutation of actinides and long lived fission products

International Nuclear Information System (INIS)

2003-05-01

High level radioactive waste disposal is an issue of great importance in the discussion of the sustainability of nuclear power generation. The main contributors to the high radioactivity are the fission products and the minor actinides. The long lived fission products and minor actinides set severe demands on the arrangements for safe waste disposal. Fast reactors and accelerator driven systems (ADS) are under development in Member States to reduce the long term hazard of spent fuel and radioactive waste, taking advantage of their incineration and transmutation capability. Important R and D programmes are being undertaken in many Member States to substantiate this option and advance the basic knowledge in this innovative area of nuclear energy development. The conceptual design of the lead cooled fast reactor concept BREST-OD-300, as well as various other conceptual designs of lead/lead-bismuth cooled fast reactors have been developed to meet enhanced safety and non-proliferation requirements, aiming at both energy production and transmutation of nuclear waste. Some R and D studies indicate that the use of lead and lead-bismuth coolant has some advantages in comparison with existing sodium cooled fast reactor systems, e.g.: simplified design of fast reactor core and BOP, enhanced inherent safety, and easier radwaste management in related fuel cycles. Moreover, various ADS conceptual designs with lead and lead-bismuth as target material and coolant also have been pursued. The results to date are encouraging, indicating that the ADS has the potential to offer an option for meeting the challenges of the back end fuel cycle. During the last decade, there have been substantial advances in several countries with their own R and D programme in the fields of lead/lead-bismuth cooled critical and sub-critical concepts. coolant technology, and experimental validation. In this context, international exchange of information and experience, as well as international

Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

Directory of Open Access Journals (Sweden)

Paula Eveline Ribeiro D’Anunciação

2013-01-01

Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

Pacemaker lead fracture without an increase in lead impedance caused by cardiac fibroma

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Daisuke Sato

2013-12-01

Full Text Available We report the case of a 64-year-old man who had a permanent pacemaker with a unipolar silicone electrode positioned in the right ventricle in 1989 for sinus node dysfunction. On a routine checkup in June 2011, a 28-mm-diameter mass was discovered, which appeared to adhere to the tricuspid valve and the ventricular lead. The size of the mass did not change for the next 6 months, and the lead impedance was maintained at around 500–600 Ω. Because pacing failure was observed in January 2012, he underwent an urgent pacemaker check; however, the lead impedance was found not to have increased greatly (689 Ω. Nevertheless, the pacemaker lead was noted to be fractured at the tricuspid level. His echocardiogram showed new severe tricuspid regurgitation and a floating mass around the lead. We extracted the fractured lead, enucleated the tumor, replaced the tricuspid valve, and placed an epicardial lead. Macroscopic examination revealed that the tumor surrounded the fractured lead and covered the stump. Pathological examination revealed that the tumor was composed of fibrous connective tissue. We presumed that electric current continued to flow through the stump of the fractured unipolar lead to the generator, and this might have caused the limited increase in lead impedance.

Hydrogen isotope double differential production cross sections induced by 62.7 MeV neutrons on a lead target

International Nuclear Information System (INIS)

Kerveno, M.; Haddad, F.; Eudes, Ph.; Kirchner, T.; Lebrun, C.; Slypen, I.; Meulders, J.P.; Le Brun, C.; Lecolley, F.R.; Lecolley, J.F.; Louvel, M.; Lefebvres, F.; Hilaire, S.; Koning, A.J.

2002-01-01

Double differential hydrogen isotope production cross sections have been extracted in 62.7 MeV neutron induced reactions on a lead target. The angular distribution was measured at eight angles from 20 deg. to 160 deg. allowing the extraction of angle-differential, energy differential, and total production cross sections. A first set of comparisons with several theoretical calculations is also presented

Influence of different moderator materials on characteristics of neutron fluxes generated under irradiation of lead target with proton beams

International Nuclear Information System (INIS)

Sosnin, A.N.; Polanski, A.; Petrochenkov, S.A.

2002-01-01

Neutron fields generated in extended heavy (Z ≥ 82) targets under irradiation with proton beams at energies in the range of 1 GeV are investigated. Influence of different moderators on the spectra and multiplicities of neutrons escaping the surface of the assembly consisting of a lead target (diam. 8 cm x 20 cm or diam. 8 cm x 50 cm) screened by variable thickness of polyethylene or graphite, respectively, was compared. It is shown that the effectiveness of graphite as a material used in such assemblies to moderate spallation neutrons down to thermal energies is significantly lower than that of paraffin

Examining the fragmentation of 158 A GeV lead ions on copper target: Charge-changing cross sections

International Nuclear Information System (INIS)

Rana, Mukhtar Ahmed; Manzoor, Shahid

2008-01-01

A stack of plastic CR-39 Track Detectors were exposed to 158 A GeV 207 Pb ions at the CERN-SPS beam facility. The exposure of stack was performed at normal incidence with a fluence of about 1500ions/cm 2 . The total number of lead ions in each spill was about 7.8x10 4 with eight spills on each stack. For the stack with the Cu target, the lengths of etched cones on one face of the CR-39 detectors (before and after the target) were measured. Using these measurements and charge identification methodology in CR-39 track detectors, total and partial charge changing cross sections of 158 A GeV Pb 82+ ions on Cu and CR-39 targets are determined in the charge region 63≤Z≤82. The possibilities of presence and absence of odd-even effect in measured partial charge changing cross sections of 158 A GeV Pb ions for Cu and CR-39 targets are described. The charge resolution (σ Z ) achieved in the present experiment is ∼0.18e-0.21e. The analysis of discrepancies between our experimental results and other published results for the identical reaction is also presented

Examining the fragmentation of 158 A GeV lead ions on copper target: Charge-changing cross sections

Energy Technology Data Exchange (ETDEWEB)

Rana, Mukhtar Ahmed [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)], E-mail: marana@alumni.nus.edu.sg; Manzoor, Shahid [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

2008-09-15

A stack of plastic CR-39 Track Detectors were exposed to 158 A GeV {sup 207}Pb ions at the CERN-SPS beam facility. The exposure of stack was performed at normal incidence with a fluence of about 1500ions/cm{sup 2}. The total number of lead ions in each spill was about 7.8x10{sup 4} with eight spills on each stack. For the stack with the Cu target, the lengths of etched cones on one face of the CR-39 detectors (before and after the target) were measured. Using these measurements and charge identification methodology in CR-39 track detectors, total and partial charge changing cross sections of 158 A GeV Pb{sup 82+} ions on Cu and CR-39 targets are determined in the charge region 63{<=}Z{<=}82. The possibilities of presence and absence of odd-even effect in measured partial charge changing cross sections of 158 A GeV Pb ions for Cu and CR-39 targets are described. The charge resolution ({sigma}{sub Z}) achieved in the present experiment is {approx}0.18e-0.21e. The analysis of discrepancies between our experimental results and other published results for the identical reaction is also presented.

Enhancement of Afterimage Colors by Surrounding Contours

Directory of Open Access Journals (Sweden)

Takao Sato

2011-05-01

Full Text Available Presenting luminance contours surrounding the adapted areas in test phase enhances color afterimages in both duration and color appearance. The presence of surrounding contour is crucial to some color phenomenon such as van Lier's afterimage, but the contour-effect itself has not been seriously examined. In this paper, we compared the contour-effect to color afterimages and to actually colored patches to examine the nature of color information subserving color-aftereffect. In the experiment, observers were adapted for 1 sec to a small colored square (red, green, yellow, or blue presented on a gray background. Then, a test field either with or without surrounding contour was presented. Observers matched the color of a test-patch located near the afterimage to the color of afterimage. It was found that the saturation of negative afterimage was almost doubled by the presence of surrounding contours. There was no effect of luminance contrast or polarity of contours. In contrast, no enhancement of saturation by surrounding contours was observed for actually colored patches even though the colors of patches were equalized to that of afterimage without contours. This dissociation in the contour-effect demonstrates the crucial difference between the color information for aftereffects and for ordinary bottom-up color perception.

Chromatic induction from surrounding stimuli under perceptual suppression.

Science.gov (United States)

Horiuchi, Koji; Kuriki, Ichiro; Tokunaga, Rumi; Matsumiya, Kazumichi; Shioiri, Satoshi

2014-11-01

The appearance of colors can be affected by their spatiotemporal context. The shift in color appearance according to the surrounding colors is called color induction or chromatic induction; in particular, the shift in opponent color of the surround is called chromatic contrast. To investigate whether chromatic induction occurs even when the chromatic surround is imperceptible, we measured chromatic induction during interocular suppression. A multicolor or uniform color field was presented as the surround stimulus, and a colored continuous flash suppression (CFS) stimulus was presented to the dominant eye of each subject. The subjects were asked to report the appearance of the test field only when the stationary surround stimulus is invisible by interocular suppression with CFS. The resulting shifts in color appearance due to chromatic induction were significant even under the conditions of interocular suppression for all surround stimuli. The magnitude of chromatic induction differed with the surround conditions, and this difference was preserved regardless of the viewing conditions. The chromatic induction effect was reduced by CFS, in proportion to the magnitude of chromatic induction under natural (i.e., no-CFS) viewing conditions. According to an analysis with linear model fitting, we revealed the presence of at least two kinds of subprocesses for chromatic induction that reside at higher and lower levels than the site of interocular suppression. One mechanism yields different degrees of chromatic induction based on the complexity of the surround, which is unaffected by interocular suppression, while the other mechanism changes its output with interocular suppression acting as a gain control. Our results imply that the total chromatic induction effect is achieved via a linear summation of outputs from mechanisms that reside at different levels of visual processing.

Content Is King: An Analysis of How the Twitter Discourse Surrounding Open Education Unfolded from 2009 to 2016

Science.gov (United States)

Paskevicius, Michael; Veletsianos, George; Kimmons, Royce

2018-01-01

Inspired by open educational resources, open pedagogy, and open source software, the openness movement in education has different meanings for different people. In this study, we use Twitter data to examine the discourses surrounding openness as well as the people who participate in discourse around openness. By targeting hashtags related to open…

Track reconstruction in the emulsion-lead target of the OPERA experiment using the ESS microscope

Science.gov (United States)

Arrabito, L.; Bozza, C.; Buontempo, S.; Consiglio, L.; Cozzi, M.; D'Ambrosio, N.; DeLellis, G.; DeSerio, M.; Di Capua, F.; Di Ferdinando, D.; Di Marco, N.; Ereditato, A.; Esposito, L. S.; Fini, R. A.; Giacomelli, G.; Giorgini, M.; Grella, G.; Ieva, M.; Janicsko Csathy, J.; Juget, F.; Kreslo, I.; Laktineh, I.; Manai, K.; Mandrioli, G.; Marotta, A.; Migliozzi, P.; Monacelli, P.; Moser, U.; Muciaccia, M. T.; Pastore, A.; Patrizii, L.; Petukhov, Y.; Pistillo, C.; Pozzato, M.; Romano, G.; Rosa, G.; Russo, A.; Savvinov, N.; Schembri, A.; Scotto Lavina, L.; Simone, S.; Sioli, M.; Sirignano, C.; Sirri, G.; Strolin, P.; Tioukov, V.; Waelchli, T.

2007-05-01

The OPERA experiment, designed to conclusively prove the existence of νμ→ντ oscillations in the atmospheric sector, makes use of a massive lead-nuclear emulsion target to observe the appearance of ντ's in the CNGS νμ beam. The location and analysis of the neutrino interactions in quasi real-time required the development of fast computer-controlled microscopes able to reconstruct particle tracks with sub-micron precision and high efficiency at a speed of ~20 cm2/h. This paper describes the performance in particle track reconstruction of the European Scanning System, a novel automatic microscope for the measurement of emulsion films developed for OPERA.

Track reconstruction in the emulsion-lead target of the OPERA experiment using the ESS microscope

International Nuclear Information System (INIS)

Arrabito, L; Bozza, C; Buontempo, S

2007-01-01

The OPERA experiment, designed to conclusively prove the existence of ν μ →ν τ oscillations in the atmospheric sector, makes use of a massive lead-nuclear emulsion target to observe the appearance of ν τ 's in the CNGS ν μ beam. The location and analysis of the neutrino interactions in quasi real-time required the development of fast computer-controlled microscopes able to reconstruct particle tracks with sub-micron precision and high efficiency at a speed of ∼20 cm 2 /h. This paper describes the performance in particle track reconstruction of the European Scanning System, a novel automatic microscope for the measurement of emulsion films developed for OPERA

Influence of Different Moderator Materials on Characteristics of Neutron Fluxes Generated under Irradiation of Lead Target with Proton Beams

CERN Document Server

Sosnin, A N; Polanski, A; Petrochenkov, S A; Golovatyuk, V M; Krivopustov, M I; Bamblevski, V P; Westmeier, W; Odoj, R; Brandt, R; Robotham, H; Hashemi-Nezhad, S R; Zamani-Valassiadou, M

2002-01-01

Neutron fields generated in extended heavy (Z\\geq 82) targets under irradiation with proton beams at energies in the range of 1 GeV are investigated. Influence of different moderators on the spectra and multiplicities of neutrons escaping the surface of the assembly consisting of a lead target (\\varnothing 8 cm\\times 20 cm or \\varnothing 8cm\\times 50 cm) screened by variable thickness of polyethylene or graphite, respectively, was compared in the present work. It is shown that the effectiveness of graphite as a material used in such assemblies to moderate spallation neutrons down to thermal energies is significantly lower than that of paraffin.

Comparison of Socioeconomic Factors between Surrounding and Non-Surrounding Areas of the Qinghai–Tibet Railway before and after Its Construction

Directory of Open Access Journals (Sweden)

Shicheng Li

2016-08-01

Full Text Available As the world’s highest railway, and the longest highland railway, the Qinghai–Tibet Railway (QTR has been paid considerable attention by researchers. However, most attention has been paid to the ecological and environmental issues affecting it, and sustainable ecological, social, and economic development-related studies of the QTR are rare. In this study, by analyzing the passenger traffic, freight traffic, passenger-kilometers, and freight-kilometers of the QTR for the period 1982–2013 and the transport structure of the Tibetan Plateau (TP for 1990–2013, the evolutionary process of the transport system in the TP following the construction of the QTR has been revealed. Subsequently, by comparing Gross Domestic Product (GDP, population, industrial structure, and urbanization level at the county and 1 km scales between surrounding and non-surrounding areas of the QTR, the differences in socioeconomic performance before and after its construction were detected. The results show that (1 in the TP, the highway-dominated transport system will break up and an integrated and sustainable transport system will form; (2 at the county scale, the annual growth rates of GDP of counties surrounding the QTR were greater than those of non-surrounding counties for the period 2000–2010. At the 1 km scale, following the opening of the completed line, the GDP of surrounding areas had a greater growth rate than before; (3 analysis at the county and 1 km scales indicated that population was not aggregated into the surrounding areas of the QTR in the period 2000–2010; (4 in terms of industrial structure, the proportion of primary industry decreased continuously, while the proportion of secondary and tertiary industries increased overall in the period 1984–2012. The QTR had no obvious impact on changes in the urbanization level of its surrounding areas.

Signaling-sensitive amino acids surround the allosteric ligand binding site of the thyrotropin receptor.

Science.gov (United States)

Kleinau, Gunnar; Haas, Ann-Karin; Neumann, Susanne; Worth, Catherine L; Hoyer, Inna; Furkert, Jens; Rutz, Claudia; Gershengorn, Marvin C; Schülein, Ralf; Krause, Gerd

2010-07-01

The thyrotropin receptor [thyroid-stimulating hormone receptor (TSHR)], a G-protein-coupled receptor (GPCR), is endogenously activated by thyrotropin, which binds to the extracellular region of the receptor. We previously identified a low-molecular-weight (LMW) agonist of the TSHR and predicted its allosteric binding pocket within the receptor's transmembrane domain. Because binding of the LMW agonist probably disrupts interactions or leads to formation of new interactions among amino acid residues surrounding the pocket, we tested whether mutation of residues at these positions would lead to constitutive signaling activity. Guided by molecular modeling, we performed site-directed mutagenesis of 24 amino acids in this spatial region, followed by functional characterization of the mutant receptors in terms of expression and signaling, measured as cAMP accumulation. We found that mutations V421I, Y466A, T501A, L587V, M637C, M637W, S641A, Y643F, L645V, and Y667A located in several helices exhibit constitutive activity. Of note is mutation M637W at position 6.48 in transmembrane helix 6, which has a significant effect on the interaction of the receptor with the LMW agonist. In summary, we found that a high proportion of residues in several helices surrounding the allosteric binding site of LMW ligands in the TSHR when mutated lead to constitutively active receptors. Our findings of signaling-sensitive residues in this region of the transmembrane bundle may be of general importance as this domain appears to be evolutionarily retained among GPCRs.

Radiological considerations on multi-MW targets Part I Induced radioactivity

CERN Document Server

Agosteo, S; Silari, M

2005-01-01

CERN is designing a Superconducting Proton Linac (SPL) to provide a 2.2GeV, 4MW proton beam to feed facilities like, for example, a future Neutrino Factory or a Neutrino SuperBeam. The material activation in such facilities is an important aspect that has to be taken into account at an early design stage. In particular, the choice of the target has consequences on the induced radioactivity and dose rates in the target itself and in its surroundings. In the present work, the radiological aspects of a stationary target made up of small tantalum pellets are compared to those of a free-surface jet of mercury. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump were performed for both targets by the Monte Carlo hadronic cascade code FLUKA. The aim was to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which...

Insights into Integrated Lead Generation and Target Identification in Malaria and Tuberculosis Drug Discovery.

Science.gov (United States)

Okombo, John; Chibale, Kelly

2017-07-18

New, safe and effective drugs are urgently needed to treat and control malaria and tuberculosis, which affect millions of people annually. However, financial return on investment in the poor settings where these diseases are mostly prevalent is very minimal to support market-driven drug discovery and development. Moreover, the imminent loss of therapeutic lifespan of existing therapies due to evolution and spread of drug resistance further compounds the urgency to identify novel effective drugs. However, the advent of new public-private partnerships focused on tropical diseases and the recent release of large data sets by pharmaceutical companies on antimalarial and antituberculosis compounds derived from phenotypic whole cell high throughput screening have spurred renewed interest and opened new frontiers in malaria and tuberculosis drug discovery. This Account recaps the existing challenges facing antimalarial and antituberculosis drug discovery, including limitations associated with experimental animal models as well as biological complexities intrinsic to the causative pathogens. We enlist various highlights from a body of work within our research group aimed at identifying and characterizing new chemical leads, and navigating these challenges to contribute toward the global drug discovery and development pipeline in malaria and tuberculosis. We describe a catalogue of in-house efforts toward deriving safe and efficacious preclinical drug development candidates via cell-based medicinal chemistry optimization of phenotypic whole-cell medium and high throughput screening hits sourced from various small molecule chemical libraries. We also provide an appraisal of target-based screening, as invoked in our laboratory for mechanistic evaluation of the hits generated, with particular focus on the enzymes within the de novo pyrimidine biosynthetic and hemoglobin degradation pathways, the latter constituting a heme detoxification process and an associated cysteine

Rhabdomyosarcoma associated with the lead wire of a pacemaker generator implant.

Science.gov (United States)

Thieman Mankin, Kelley M; Dunbar, Mark D; Toplon, David; Ginn, Pamela; Maisenbacher, Herbert W; Risselada, Marije

2014-06-01

An 11-year-old female spayed Labrador Retriever was presented for a draining, painful subcutaneous mass palpated over a previously implanted pacemaker generator. Infection was suspected and the mass was removed surgically. On cut surface, the mass was friable and mottled tan to brown with firm pale tan nodules, surrounding the pacemaker lead wire adjacent to the pacemaker generator. Cytologic interpretation of impression smears was consistent with a sarcoma, and suggestive of a rhabdomyosarcoma due to the presence of strap-like cells. On histopathologic examination, a highly invasive nodular mass surrounded the pacemaker lead, composed of pleomorphic round, spindle and strap cells, and multinucleated giant cells. The population exhibited microscopic invasion into the deep portion of the fibrous capsule surrounding the pacemaker generator. There were tumor emboli within small to medium subcutaneous veins adjacent to the mass. Immunohistochemically, the neoplastic cells stained positive for α-sarcomeric actin and vimentin, and negative for α-smooth muscle actin, consistent with a rhabdomyosarcoma arising at the site of the pacemaker generator. To our knowledge, this is the first report of a rhabdomyosarcoma associated with the lead wire of a pacemaker generator in a dog. © 2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.

Effect of lead nitrate on the liver of the cichlid fish (Oreochromis niloticus): a light microscope study.

Science.gov (United States)

Khidr, Bothaina M; Mekkawy, Imam A A; Harabawy, Ahmed S A; Ohaida, Abdel Salam M I

2012-09-15

The adverse impacts of heavy metals on fish liver were evident with great variability among organs and species. The present study deals with the histological changes of the hepatocytes of the Nile tilapia, Oreochromis niloticus, following exposure to 2.5, 5, 10 ppm of lead nitrate for 1, 2, 3, 4 weeks. The present results revealed that lead nitrate exerts some histological effects on the hepatic tissue after exposure to the first concentration in the form of dilatation and congestion of the blood vessels, vacuolation of hepatic cells, proliferation of connective tissue and hepatic necrosis. Leucocyte aggregation-mostly lymphatic in nature-was seen infiltrating hepatic tissue. These alterations became more pronounced in liver of fishes exposed to second concentrations indicating more progressive signs of necrosis. The presence of eosinophilic oedematous areas surrounding some blood vessels was also observed. Finally, at the third concentration, in addition to the above alterations, melanomacrophages, which store lipofuscin at the site of necrosis, were observed. These histological results imply that the fish liver may serve as a target organ for the toxicity of sublethal concentrations of lead nitrate.

Monitoring program of surrounding of the NPP SE-EBO

International Nuclear Information System (INIS)

Dobis, L.; Kostial, J.

1997-01-01

The paper dealt with monitoring program of radiation control of surrounding of the NPP Bohunice, which has the aim: (1) to ensure the control of influence of work of the NPP Bohunice on the environment in their surrounding; (2) to ensure the back-ground for regular brief of control and supervisory organs about condition of the environment in surrounding of the NPP Bohunice; (3) to maintain the expected technical level of control of the NPP Bohunice and to exploit optimally the technical means; (4) to solicit permanently the data about the radioactivity of environment in surrounding of the NPP Bohunice for forming of files of the data; (5) to exploit purposefully the technical equipment, technical workers and to maintain their in permanent emergency and technical eligibility for the case of the breakdown; (6) to obtain permanently the files of the values for qualification of the reference levels. This program of monitoring includes the radiation control of surrounding of the NPP Bohunice, in the time of normal work of power-station's blocks, inclusively of all types of trouble-shooting and repairer works in surrounding of the NPP Bohunice, up to distance 20 km from power-station. The monitoring includes: outlets from the NPP Bohunice, monitoring of radiation characteristics in surrounding of the NPP Bohunice, (aerosols, fall-outs, soil), the links of food chains: (grass and fodder, milk, agriculture products), hydrosphere in surrounding (surface waters, drink water, bores of radiation control in complex of the NPP Bohunice, components of the hydrosphere), measurement of radiation from external sources (measurement of the dose rates, measurement of the doses [sk

Simulation of electron, positron and Bremsstrahlung spectrum generated due to electromagnetic cascade by 2.5 GeV electron hitting lead target using FLUKA code

International Nuclear Information System (INIS)

Sahani, P.K.; Dev, Vipin; Haridas, G.; Thakkar, K.K.; Singh, Gurnam; Sarkar, P.K.; Sharma, D.N.

2009-01-01

INDUS-2 is a high energy electron accelerator facility where electrons are accelerated in circular ring up to maximum energy 2.5 GeV, to generate synchrotron radiation. During normal operation of the machine a fraction of these electrons is lost, which interact with the accelerator structures and components like vacuum chamber and residual gases in the cavity and hence generates significant amount of Bremsstrahlung radiation. The Bremsstrahlung radiation is highly dependent on the incident electron energy, target material and its thickness. The Bremsstrahlung radiation dominates the radiation environment in such electron storage rings. Because of its broad spectrum extending up to incident electron energy and pulsed nature, it is very difficult to segregate the Bremsstrahlung component from the mixed field environment in accelerators. With the help of FLUKA Monte Carlo code, Bremsstrahlung spectrum generated from 2.5 GeV electron on bombardment of high Z lead target is simulated. To study the variation in Bremsstrahlung spectrum on target thickness, lead targets of 3, 6, 9, 12, 15, 18 mm thickness was used. The energy spectrum of emerging electron and positron is also simulated. The study suggests that as the target thickness increases, the emergent Bremsstrahlung photon fluence increases. With increase in the target thickness Bremsstrahlung photons in the spectrum dominate the low energy part and degrade in high energy part. The electron and positron spectra also extend up to incident electron energy. (author)

Stimulus size dependence of hue changes induced by chromatic surrounds.

Science.gov (United States)

Kellner, Christian Johannes; Wachtler, Thomas

2016-03-01

A chromatic surround induces a change in the perceived hue of a stimulus. This shift in hue depends on the chromatic difference between the stimulus and the surround. We investigated how chromatic induction varies with stimulus size and whether the size dependence depends on the surround hue. Subjects performed asymmetric matching of color stimuli with different sizes in surrounds of different chromaticities. Generally, induced hue shifts decreased with increasing stimulus size. This decrease was quantitatively different for different surround hues. However, when size effects were normalized to an overall induction strength, the chromatic specificity was largely reduced. The separability of inducer chromaticity and stimulus size suggests that these effects are mediated by different neural mechanisms.

Explaining preferences for home surroundings and locations

DEFF Research Database (Denmark)

Andersen, Hans Skifter

2011-01-01

This article is based on a survey carried out in Denmark that asked a random sample of the population about their preferences for home surroundings and locations. It shows that the characteristics of social surroundings are very important and can be divided into three independent dimensions......: avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places...... with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific...

HIV behavioural surveillance among refugees and surrounding host ...

African Journals Online (AJOL)

We used a standardised behavioural surveillance survey (BSS), modified to be directly relevant to populations in conflict and post-conflict settings as well as to their surrounding host populations, to survey the populations of a refugee settlement in south-western Uganda and its surrounding area. Two-stage probability ...

Development of the urban space surrounding selected railway stations in Poland

Directory of Open Access Journals (Sweden)

Dragan Weronika

2017-12-01

Full Text Available At present, many railway stations, in spite of being architecturally valuable, are subject to de-capitalization and degradation, which increasingly leads to demolition including elements or even entire railway stations of historical importance. Therefore, there arises a need to transform these facilities – as well as their nearby surroundings – into service areas not only for railway passengers but also for the consumer or tourist. This article presents an overview of the types of development of functional and spatial areas around a railway station, as well as the building itself, on selected examples in cities of Poland. In past historical periods, the surroundings of railway stations often became the new core of the studied centres, creating new urban structures. Train station forecourts, as well as access roads leading to railway stations, became specific links of railway infrastructure, the main points of which were railway stations, with the original urban layout. Unfortunately, the decline in the importance of rail transport has contributed to the recession and degradation of these spaces, and often to changes in their functions. This article refers to the concept of redevelopment of the railway station area, which emphasizes the creation of hubs integrating various modes of transport on the one hand, and transforming the area around the stations into an area of development of new business activities, on the other. Some of the discussed train stations have undergone a thorough renovation (e.g. Kraków Główny, Katowice and Poznań Główny, frequently in an attempt to allude to global trends in the commercialization of space and transport integration within station squares. However, this poses a problem and a challenge for decision-makers attempting to redevelop such facilities and the spaces associated with them.

The surrounding tissue modifies the placental stem villous vascular responses

DEFF Research Database (Denmark)

Brøgger, Torbjørn; Forman, Axel; Aalkjær, Christian

2014-01-01

is available. In-depth understanding of the mechanisms involved in control of placental vascular tone are needed to develop new tissue targets for therapeutic intervention. Method: From fresh born placentas segments of stem villous arteries were carefully dissected. The artery branches were divided....... The surrounding trophoblast was removed from one end and left intact in the other, and the segment was divided to give two ring preparations, with or without trophoblast. The preparations were mounted in wire myographs and responses to vasoactive agents were compared. Results: pD2values for PGF2α, Tx-analog U...... or endotheline-1. These differences partly disappeared in the presence of L-NAME. Conclusion: The perivascular tissue significantly reduces sensitivity and force development of stem villous arteries, partly due to release of NO This represents a new mechanism for control of human stem villous artery tone....

Spectrum analysis in lead spectrometer for isotopic fissile assay in used fuel

International Nuclear Information System (INIS)

Lee, Y.D.; Park, C.J.; Kim, H.D.; Song, K.C.

2014-01-01

The LSDS system is under development for analyzing isotopic fissile content applicable in a hot cell for the pyro process. The fuel assay area and nuclear material composition were selected for simulation. The source mechanism for efficient neutron generation was also determined. A neutron is produced at the Ta target by hitting it from accelerated electron. The parameters for an electron accelerator are being researched for cost effectiveness, easy maintenance, and compact size. The basic principle of LSDS is that isotopic fissile has its own fission structure below the unresolved resonance region. The source neutron interacts with a lead medium and produces continuous neutron energy, which generates dominant fission at each fissile. Therefore, a spectrum analysis is very important at a lead medium and fuel area for system working. The energy spectrum with respect to slowing down energy and the energy resolution were investigated in lead. A spectrum analysis was done by the existence of surrounding detectors. In particular, high resonance energy was considered. The spectrum was well organized at each slowing down energy and the energy resolution was acceptable to distinguish isotopic fissile fissions. Additionally, LSDS is applicable for the optimum design of spent fuel storage and management.The isotopic fissile content assay will increase the transparency and credibility for spent fuel storage and its re-utilization, as demanded internationally. (author)

Circumstances surrounding aneurysmal subarachnoid hemorrhage

NARCIS (Netherlands)

Schievink, W. I.; Karemaker, J. M.; Hageman, L. M.; van der Werf, D. J.

1989-01-01

The circumstances surrounding aneurysmal subarachnoid hemorrhage were investigated in a group of 500 consecutive patients admitted to a neurosurgical center. Subarachnoid hemorrhage occurred during stressful events in 42.8% of the patients, during nonstrenuous activities in 34.4%, and during rest or

A Study of the Flow Field Surrounding Interacting Line Fires

Directory of Open Access Journals (Sweden)

Trevor Maynard

2016-01-01

Full Text Available The interaction of converging fires often leads to significant changes in fire behavior, including increased flame length, angle, and intensity. In this paper, the fluid mechanics of two adjacent line fires are studied both theoretically and experimentally. A simple potential flow model is used to explain the tilting of interacting flames towards each other, which results from a momentum imbalance triggered by fire geometry. The model was validated by measuring the velocity field surrounding stationary alcohol pool fires. The flow field was seeded with high-contrast colored smoke, and the motion of smoke structures was analyzed using a cross-correlation optical flow technique. The measured velocities and flame angles are found to compare reasonably with the predicted values, and an analogy between merging fires and wind-blown flames is proposed.

Diagnostic radiopharmaceuticals for localization in target tissues exhibiting a regional pH shift relative to surrounding tissues

International Nuclear Information System (INIS)

Blau, M.; Kung, H.F.

1985-01-01

Diagnostic radiopharmaceutical compounds are provided which are capable of entering a target tissue or a target organ by passive diffusion through cell walls and which are effectively accumulated and retained within the target tissue or organ due to a regional pH shift. Such compounds are desirably readily accessible synthetically using readily available radionuclides. The compound comprises a radioactive isotope of an element in chemical combination with at least one amine group and preferably with at least two secondary or tertiary amine groups. The radioactive element is an element other than iodine emitting gamma ray, x-ray or positron radiation. When the element is a gamma ray emitting isotope, at least 75 percent of the number of emissions is emitted at energies of between 80 and 400 keV. The half-life of the isotope is usually between two minutes and 15 days. The compound has acid-base characteristics such that the state of ionization of the compound at the pH of the body is significantly different and usually less than its state of ionization at the intracellular pH of the target tissue. The compound has such lipid solubility characteristics that it is capable of ready penetration through cell walls, but within cells its lipid solubility is substantially decreased, whereby the ability of the compound to leave the target tissue is substantially diminished. Specific data relevant to di-beta-(piperidinoethyl)-selenide and di-beta-(morpholinoethyl)-selenide in rat brains are presented

Radiopharmaceuticals for localization in target tissues exhibiting a regional pH shift relative to surrounding tissues

International Nuclear Information System (INIS)

Blau, M.; Kung, H.F.

1981-01-01

This patent relates to the preparation and use of radiopharmaceutical chemical compounds comprising a radioactive isotope, other than an isotope of iodine, in chemical combination with at least one primary, secondary or tertiary amino group. The compounds have a lipophilicity sufficiently high at a pH of 7.6 to permit passage of the compound from the blood of a mammal into a target organ or tissue and sufficiently low at a pH of 6.6 to prevent rapid return of the compound from the target organ or tissue to the blood. The compounds have a percent protein binding of less than ninety percent. These compounds may be selectively deposited in at least one target tissue or organ of a mammal, the tissue or organ of which has a significantly different intracellular pH than the blood of the mammal, by introducing the compound of the invention into the bloodstream of the mammal. A plurality of selenide compounds containing Se-75 isotope are claimed in relation to the patent. (U.K.)

Ecotoxicology: Lead

Science.gov (United States)

Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

2008-01-01

Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

Monte Carlo simulations and experimental results on neutron production in the spallation target QUINTA irradiated with 660 MeV protons

International Nuclear Information System (INIS)

Khushvaktov, J.H.; Yuldashev, B.S.; Adam, J.; Vrzalova, J.; Baldin, A.A.; Furman, W.I.; Gustov, S.A.; Kish, Yu.V.; Solnyshkin, A.A.; Stegailov, V.I.; Tichy, P.; Tsoupko-Sitnikov, V.M.; Tyutyunnikov, S.I.; Zavorka, L.; Svoboda, J.; Zeman, M.; Vespalec, R.; Wagner, V.

2017-01-01

The activation experiment was performed using the accelerated beam of the Phasotron accelerator at the Joint Institute for Nuclear Research (JINR). The natural uranium spallation target QUINTA was irradiated with protons of energy 660 MeV. Monte Carlo simulations were performed using the FLUKA and Geant4 codes. The number of leakage neutrons from the sections of the uranium target surrounded by the lead shielding and the number of leakage neutrons from the lead shield were determined. The total number of fissions in the setup QUINTA were determined. Experimental values of reaction rates for the produced nuclei in the "1"2"7I sample were obtained, and several values of the reaction rates were compared with the results of simulations by the FLUKA and Geant4 codes. The experimentally determined fluence of neutrons in the energy range of 10-200 MeV using the (n, xn) reactions in the "1"2"7I(NaI) sample was compared with the results of simulations. Possibility of transmutation of the long-lived radionuclide "1"2"9I in the QUINTA setup was estimated. [ru

Factors leading to inflation targeting : The impact of adoption

NARCIS (Netherlands)

Samarina, Anna; Sturm, Jan-Egbert

2013-01-01

This paper examines how the analysis of inflation targeting (IT) adoption is affected by allowing for a structural change after adoption, using panel probit models for 60 countries over the period 1985-2008. Our findings suggest that there is a structural change after IT adoption. Including the

Factors leading to inflation targeting - the impact of adoption

NARCIS (Netherlands)

Samarina, Anna; Sturm, Jan-Egbert

2013-01-01

This paper examines how the analysis of inflation targeting (IT) adoption is affected by the choice of the analyzed period. We test whether country characteristics influence the decision to apply IT differently before and after its adoption, using panel probit models for 60 countries over the period

Measurements of spallation neutrons from a thick lead target bombarded with 0.5 and 1.5 GeV protons

Energy Technology Data Exchange (ETDEWEB)

Meigo, Shin-ichiro; Takada, Hiroshi; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

1997-03-01

Double differential neutron spectra from a thick lead target bombarded with 0.5 and 1.5 GeV protons have been measured with the time-of-flight technique. In order to obtain the neutron spectra without the effect of the flight time fluctuation by neutron scattering in the target, an unfolding technique has also been employed in the low energy region below 3 MeV. The measured data have been compared with the calculated results of NMTC/JAERI-MCNP-4A code system. It has been found that the code system gives about 50 % lower neutron yield than the experimental ones in the energy region between 20 and 80 MeV for both incident energies. The disagreements, however, have been improved well by taking account of the inmedium nucleon-nucleon scattering cross sections in the NMTC/JAERI code. (author)

Spallation neutron source target station design, development, and commissioning

Energy Technology Data Exchange (ETDEWEB)

Haines, J.R., E-mail: hainesjr@ornl.gov; McManamy, T.J.; Gabriel, T.A.; Battle, R.E.; Chipley, K.K.; Crabtree, J.A.; Jacobs, L.L.; Lousteau, D.C.; Rennich, M.J.; Riemer, B.W.

2014-11-11

The spallation neutron source target station is designed to safely, reliably, and efficiently convert a 1 GeV beam of protons to a high flux of about 1 meV neutrons that are available at 24 neutron scattering instrument beam lines. Research and development findings, design requirements, design description, initial checkout testing, and results from early operation with beam are discussed for each of the primary target subsystems, including the mercury target, neutron moderators and reflector, surrounding vessels and shielding, utilities, remote handling equipment, and instrumentation and controls. Future plans for the mercury target development program are also briefly discussed.

Tomatidine Is a Lead Antibiotic Molecule That Targets Staphylococcus aureus ATP Synthase Subunit C.

Science.gov (United States)

Lamontagne Boulet, Maxime; Isabelle, Charles; Guay, Isabelle; Brouillette, Eric; Langlois, Jean-Philippe; Jacques, Pierre-Étienne; Rodrigue, Sébastien; Brzezinski, Ryszard; Beauregard, Pascale B; Bouarab, Kamal; Boyapelly, Kumaraswamy; Boudreault, Pierre-Luc; Marsault, Éric; Malouin, François

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of deadly hospital-acquired infections. The discovery of anti- Staphylococcus antibiotics and new classes of drugs not susceptible to the mechanisms of resistance shared among bacteria is imperative. We recently showed that tomatidine (TO), a steroidal alkaloid from solanaceous plants, possesses potent antibacterial activity against S. aureus small-colony variants (SCVs), the notoriously persistent form of this bacterium that has been associated with recurrence of infections. Here, using genomic analysis of in vitro -generated TO-resistant S. aureus strains to identify mutations in genes involved in resistance, we identified the bacterial ATP synthase as the cellular target. Sequence alignments were performed to highlight the modified sequences, and the structural consequences of the mutations were evaluated in structural models. Overexpression of the atpE gene in S. aureus SCVs or introducing the mutation found in the atpE gene of one of the high-level TO-resistant S. aureus mutants into the Bacillus subtilis atpE gene provided resistance to TO and further validated the identity of the cellular target. FC04-100, a TO derivative which also possesses activity against non-SCV strains, prevents high-level resistance development in prototypic strains and limits the level of resistance observed in SCVs. An ATP synthesis assay allowed the observation of a correlation between antibiotic potency and ATP synthase inhibition. The selectivity index (inhibition of ATP production by mitochondria versus that of bacterial ATP synthase) is estimated to be >10 5 -fold for FC04-100. Copyright © 2018 American Society for Microbiology.

Pathways for the release of polonium from a lead-bismuth spallation target (thermochemical calculation); Verfluechtigungspfade des Poloniums aus einem Pb-Bi-Spallationstarget (Thermochemische Kalkulation)

Energy Technology Data Exchange (ETDEWEB)

Eichler, B.; Neuhausen, J

2004-06-01

An analysis of literature data for the thermochemical constants of polonium reveals considerable discrepancies in the relations of these data among each other as well as in their expected trends within the chalcogen group. This fact hinders a reliable assessment of possible reaction paths for the release of polonium from a liquid lead-bismuth spallation target. In this work an attempt is made to construct a coherent data set for the thermochemical properties of polonium and some of its compounds that are of particular importance with respect to the behaviour of polonium in a liquid Pb-Bi target. This data set is based on extrapolations using general trends throughout the periodic table and, in particular, within the chalcogen group. Consequently, no high accuracy should be attributed to the derived data set. However, the data set derived in this work is consistent with definitely known experimental data. Furthermore, it complies with the general trends of physicochemical properties within the chalcogen group. Finally, well known relations between thermochemical quantities are fulfilled by the data derived in this work. Thus, given the lack of accurate experimental data it can be regarded as best available data. Thermochemical constants of polonium hydride, lead polonide and polonium dioxide are derived based on extrapolative procedures. Furthermore, the possibility of formation of the gaseous intermetallic molecule BiPo, which has been omitted from discussion up to now, is investigated. From the derived thermochemical data the equilibrium constants of formation, release and dissociation reactions are calculated for different polonium containing species. Furthermore equilibrium constants are determined for the reaction of lead polonide and polonium dioxide with hydrogen, water vapour and the target components lead and bismuth. The most probable release pathways are discussed. From thermochemical evaluations polonium is expected to be released from liquid lead

Selective targeting of the mTORC1/2 protein kinase complexes leads to antileukemic effects in vitro and in vivo

International Nuclear Information System (INIS)

Schuster, K; Zheng, J; Arbini, A A; Zhang, C C; Scaglioni, P P

2011-01-01

The BCR/ABL tyrosine kinase promotes leukemogenesis through activation of several targets that include the phosphoinositide 3-kinase (PI3K). Tyrosine kinase inhibitors (TKIs), which target BCR/ABL, induce striking clinical responses. However, therapy with TKIs is associated with limitations such as drug intolerance, inability to universally eradicate the disease and emergence of BCR/ABL drug-resistant mutants. To overcome these limitations, we tested whether inhibition of the PI3K/target of rapamycin (mTOR) signaling pathway has antileukemic effect in primary hematopoietic stem cells and BA/F3 cells expressing the BCR/ABL oncoprotein. We determined that dual inhibition of PI3K/mTOR causes growth arrest and apoptosis leading to profound antileukemic effects both in vitro and in vivo. We also established that pharmacologic inhibition of the mTORC1/mTORC2 complexes is sufficient to cause these antileukemic effects. Our results support the development of inhibitors of the mTORC1/2 complexes for the therapy of leukemias that either express BCR/ABL or display deregulation of the PI3K/mTOR signaling pathway

Placental vascular responses are dependent on surrounding tissue

DEFF Research Database (Denmark)

Brøgger, Torbjørn Halle

-depth understanding of the mechanism regulating blood flow and perfusion is necessary if we are to come up with new ideas for intervention and treatment. Method: From fresh born placentas stem villi arteries were carefully dissected. The artery branches were divided. The surrounding tissue was removed from one end...... and was left untouched in the other end. Then using wire myography they were investigated in terms of contractility and sensitivity to physiological relevant human-like agonists. Results: Sensitivity to PGF2α, Tx-analog, 5-HT and endothelin-1 was significantly lower in arteries with intact surrounding tissue...... compared to arteries stripped of the tissue. The maximal force development was also significantly lower in arteries with surrounding tissue, when they were depolarized high extracellular [K+] or stimulated with PGF2α or endotheline-1. Conclusion: The perivascular tissue significantly alters stem villi...

Placental vascular responses are dependent on surrounding tissue

DEFF Research Database (Denmark)

Brøgger, Torbjørn Halle

. Materials and methods. From fresh born placentas, stem villi arteries were carefully dissected. The artery branches were divided. The surrounding tissue was removed from one end and was left untouched in the other end.Then, using wire myography, they were investigated in terms of contractility...... and sensitivity to physiological relevant human-like agonists. Results. Sensitivity to PGF2α, Tx-analog, 5-HT and endothelin-1 was significantly lower in arteries with intact surrounding tissue compared to arteries stripped of the tissue. The maximal force development was also significantly lower in arteries...... with surrounding tissue when they were depolarized high extracellular [K+] or stimulated with PGF2α or endotheline-1. Conclusion. The perivascular tissue significantly alters stem villi arteries' sensitivity and force development in a suppressive way. This implicates a new aspect of blood flow regulation...

A synchronous surround increases the motion strength gain of motion.

Science.gov (United States)

Linares, Daniel; Nishida, Shin'ya

2013-11-12

Coherent motion detection is greatly enhanced by the synchronous presentation of a static surround (Linares, Motoyoshi, & Nishida, 2012). To further understand this contextual enhancement, here we measured the sensitivity to discriminate motion strength for several pedestal strengths with and without a surround. We found that the surround improved discrimination of low and medium motion strengths, but did not improve or even impaired discrimination of high motion strengths. We used motion strength discriminability to estimate the perceptual response function assuming additive noise and found that the surround increased the motion strength gain, rather than the response gain. Given that eye and body movements continuously introduce transients in the retinal image, it is possible that this strength gain occurs in natural vision.

The design of a lead-bismuth target system with a dual injection tube

International Nuclear Information System (INIS)

Cho, C.H.; Kim, Y.; Song, T.Y.; Park, W.S.

2005-01-01

A spallation target system is a key component to be developed for an accelerator driven system (ADS). It is known that a 15 ∼ 25 MW spallation target is required for a practical 1000 MWth ADS. The design of a 20 MW spallation target is very challenging because more than 60% of the beam power is deposited as heat in a small volume of the target system. In the present work, a numerical design study was performed to obtain the optimal design parameters for a 20 MW spallation target for a 1000 MW ADS. A dual injection tube was proposed for the reduction of the LBE flow rate at the target channel. The results of the present study show that a 30 cm wide proton beam with a uniform beam distribution should be adopted for the spallation target of a 20 MW power. When the dual LBE injection tube is employed, the LBE flow rate could be reduced by a factor of 4 without reducing the maximum allowable beam current. (authors)

Energy deposition in a thin copper target downstream and off-axis of a proton-radiography target

International Nuclear Information System (INIS)

Greene, G.A.; Finfrock, C.C.; Snead, C.L.; Hanson, A.L.; Murray, M.M.

2002-01-01

A series of proton energy-deposition experiments was conducted to measure the energy deposited in a copper target located downstream and off-axis of a high-energy proton-radiography target. The proton/target interactions involved low-intensity bunches of protons at 24 GeV/c onto a spherical target consisting of concentric shells of tungsten and copper. The energy-deposition target was placed at five locations downstream of the proton-radiography target, off-axis of the primary beam transport, and was either unshielded or shielded by 5 or 10 cm of lead. Maximum temperature rises measured in the energy-deposition target due to single bunches of 5x10 10 protons on the proton-radiography target were approximately 20 mK per bunch. The data indicated that the scattered radiation was concentrated close to the primary transport axis of the beam line. The energy deposited in the energy-deposition target was reduced by moving the target radially away from the primary transport axis. Placing lead shielding in front of the target further reduced the energy deposition. The measured temperature rises of the energy-deposition target were empirically correlated with the distance from the source, the number of protons incident on the proton-radiography target, the thickness of the lead shielding, and the angle of the energy-deposition target off-axis of the beam line from the proton-radiography target. The correlation of the experimental data that was developed provides a starting point for the evaluation of the shielding requirements for devices downstream of proton-radiography targets such as superconducting magnets

Genomes2Drugs: identifies target proteins and lead drugs from proteome data.

LENUS (Irish Health Repository)

Toomey, David

2009-01-01

BACKGROUND: Genome sequencing and bioinformatics have provided the full hypothetical proteome of many pathogenic organisms. Advances in microarray and mass spectrometry have also yielded large output datasets of possible target proteins\\/genes. However, the challenge remains to identify new targets for drug discovery from this wealth of information. Further analysis includes bioinformatics and\\/or molecular biology tools to validate the findings. This is time consuming and expensive, and could fail to yield novel drugs if protein purification and crystallography is impossible. To pre-empt this, a researcher may want to rapidly filter the output datasets for proteins that show good homology to proteins that have already been structurally characterised or proteins that are already targets for known drugs. Critically, those researchers developing novel antibiotics need to select out the proteins that show close homology to any human proteins, as future inhibitors are likely to cross-react with the host protein, causing off-target toxicity effects later in clinical trials. METHODOLOGY\\/PRINCIPAL FINDINGS: To solve many of these issues, we have developed a free online resource called Genomes2Drugs which ranks sequences to identify proteins that are (i) homologous to previously crystallized proteins or (ii) targets of known drugs, but are (iii) not homologous to human proteins. When tested using the Plasmodium falciparum malarial genome the program correctly enriched the ranked list of proteins with known drug target proteins. CONCLUSIONS\\/SIGNIFICANCE: Genomes2Drugs rapidly identifies proteins that are likely to succeed in drug discovery pipelines. This free online resource helps in the identification of potential drug targets. Importantly, the program further highlights proteins that are likely to be inhibited by FDA-approved drugs. These drugs can then be rapidly moved into Phase IV clinical studies under \\'change-of-application\\' patents.

Genomes2Drugs: identifies target proteins and lead drugs from proteome data.

Directory of Open Access Journals (Sweden)

David Toomey

Full Text Available BACKGROUND: Genome sequencing and bioinformatics have provided the full hypothetical proteome of many pathogenic organisms. Advances in microarray and mass spectrometry have also yielded large output datasets of possible target proteins/genes. However, the challenge remains to identify new targets for drug discovery from this wealth of information. Further analysis includes bioinformatics and/or molecular biology tools to validate the findings. This is time consuming and expensive, and could fail to yield novel drugs if protein purification and crystallography is impossible. To pre-empt this, a researcher may want to rapidly filter the output datasets for proteins that show good homology to proteins that have already been structurally characterised or proteins that are already targets for known drugs. Critically, those researchers developing novel antibiotics need to select out the proteins that show close homology to any human proteins, as future inhibitors are likely to cross-react with the host protein, causing off-target toxicity effects later in clinical trials. METHODOLOGY/PRINCIPAL FINDINGS: To solve many of these issues, we have developed a free online resource called Genomes2Drugs which ranks sequences to identify proteins that are (i homologous to previously crystallized proteins or (ii targets of known drugs, but are (iii not homologous to human proteins. When tested using the Plasmodium falciparum malarial genome the program correctly enriched the ranked list of proteins with known drug target proteins. CONCLUSIONS/SIGNIFICANCE: Genomes2Drugs rapidly identifies proteins that are likely to succeed in drug discovery pipelines. This free online resource helps in the identification of potential drug targets. Importantly, the program further highlights proteins that are likely to be inhibited by FDA-approved drugs. These drugs can then be rapidly moved into Phase IV clinical studies under 'change-of-application' patents.

Cytoplasmic movement profiles of mouse surrounding nucleolus and not-surrounding nucleolus antral oocytes during meiotic resumption.

Science.gov (United States)

Bui, Thi Thu Hien; Belli, Martina; Fassina, Lorenzo; Vigone, Giulia; Merico, Valeria; Garagna, Silvia; Zuccotti, Maurizio

2017-05-01

Full-grown mouse antral oocytes are classified as surrounding nucleolus (SN) or not-surrounding nucleolus (NSN), depending on the respective presence or absence of a ring of Hoechst-positive chromatin surrounding the nucleolus. In culture, both types of oocytes resume meiosis and reach the metaphase II (MII) stage, but following insemination, NSN oocytes arrest at the two-cell stage whereas SN oocytes may develop to term. By coupling time-lapse bright-field microscopy with image analysis based on particle image velocimetry, we provide the first systematic measure of the changes to the cytoplasmic movement velocity (CMV) occurring during the germinal vesicle-to-MII (GV-to-MII) transition of these two types of oocytes. Compared to SN oocytes, NSN oocytes display a delayed GV-to-MII transition, which can be mostly explained by retarded germinal vesicle break down and first polar body extrusion. SN and NSN oocytes also exhibit significantly different CMV profiles at four main time-lapse intervals, although this difference was not predictive of SN or NSN oocyte origin because of the high variability in CMV. When CMV profile was analyzed through a trained artificial neural network, however, each single SN or NSN oocyte was blindly identified with a probability of 92.2% and 88.7%, respectively. Thus, the CMV profile recorded during meiotic resumption may be exploited as a cytological signature for the non-invasive assessment of the oocyte developmental potential, and could be informative for the analysis of the GV-to-MII transition of oocytes of other species. © 2017 Wiley Periodicals, Inc.

Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

Directory of Open Access Journals (Sweden)

Hao Sun

2013-06-01

Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real-world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

MRI-induced heating of deep brain stimulation leads

International Nuclear Information System (INIS)

Mohsin, Syed A; Sheikh, Noor M; Saeed, Usman

2008-01-01

The radiofrequency (RF) field used in magnetic resonance imaging is scattered by medical implants. The scattered field of a deep brain stimulation lead can be very intense near the electrodes stimulating the brain. The effect is more pronounced if the lead behaves as a resonant antenna. In this paper, we examine the resonant length effect. We also use the finite element method to compute the near field for (i) the lead immersed in inhomogeneous tissue (fat, muscle, and brain tissues) and (ii) the lead connected to an implantable pulse generator. Electric field, specific absorption rate and induced temperature rise distributions have been obtained in the brain tissue surrounding the electrodes. The worst-case scenario has been evaluated by neglecting the effect of blood perfusion. The computed values are in good agreement with in vitro measurements made in the laboratory.

Biological characterization of lead-enhanced exopolysaccharide produced by a lead resistant Enterobacter cloacae strain P2B.

Science.gov (United States)

Naik, Milind Mohan; Pandey, Anju; Dubey, Santosh Kumar

2012-09-01

A lead resistant bacterial strain isolated from effluent of lead battery manufacturing company of Goa, India has been identified as Enterobacter cloacae strain P2B based on morphological, biochemical characters, FAME profile and 16S rDNA sequence data. This bacterial strain could resist lead nitrate up to 1.6 mM. Significant increase in exopolysaccharide (EPS) production was observed as the production increased from 28 to 108 mg/L dry weight when exposed to 1.6 mM lead nitrate in Tris buffered minimal medium. Fourier-transformed infrared spectroscopy of this EPS revealed presence of several functional groups involved in metal binding viz. carboxyl, hydroxyl and amide groups along with glucuronic acid. Gas chromatography coupled with mass spectrometry analysis of alditol-acetate derivatives of acid hydrolysed EPS produced in presence of 1.6 mM lead nitrate demonstrated presence of several neutral sugars such as rhamnose, arabinose, xylose, mannose, galactose and glucose, which contribute to lead binding hydroxyl groups. Scanning electron microscope coupled with energy dispersive X-ray spectrometric analysis of this lead resistant strain exposed to 1.6 mM lead nitrate interestingly revealed mucous EPS surrounding bacterial cells which sequestered 17 % lead (as weight %) extracellularly and protected the bacterial cells from toxic effects of lead. This lead resistant strain also showed multidrug resistance. Thus these results significantly contribute to better understanding of structure, function and environmental application of lead-enhanced EPSs produced by bacteria. This lead-enhanced biopolymer can play a very important role in bioremediation of several heavy metals including lead.

Influence of Surrounding Colors in the Illuminant-Color Mode on Color Constancy

Directory of Open Access Journals (Sweden)

Kazuho Fukuda

2011-05-01

Full Text Available On color constancy, we showed that brighter surrounding colors had greater influence than dim colors (Uchikawa, Kitazawa, MacLeod, Fukuda, 2010 APCV. Increasing luminance of a stimulus causes the change in appearance from the surface-color to the illuminant-color mode. However it is unknown whether the visual system considers such color appearance mode of surrounding colors to achieve color constancy. We investigated the influence of surrounding colors that appeared illuminant on color constancy. The stimulus was composed of a central test stimulus and surrounding six colors: bright and dim red, green and blue. The observers adjusted the chromaticity of the test stimulus to be appeared as an achromatic surface. The luminance balance of three bright surrounding colors was equalized with that of the optimal colors in three illuminant conditions, then, the luminance of one of the three bright colors was varied in the range beyond the critical luminance of color appearance mode transition. The results showed that increasing luminance of a bright surrounding color shifted the observers' achromatic setting toward its chromaticity, but this effect diminished for the surrounding color in the illuminant-color mode. These results suggest that the visual system considers color appearance mode of surrounding colors to accomplish color constancy.

P1-13: Color Induction from Surround Color under Interocular Suppression

Directory of Open Access Journals (Sweden)

Ichiro Kuriki

2012-10-01

Full Text Available The effect of surround colors on color appearance is known to subserve color constancy in humans, but how multiple mechanisms in the visual system are involved in this effect is controversial. We used an interocular-suppression technique to examine how the effect occurs at the level higher than the interaction of binocular information. A test color chip (1.7 × 1.7 deg visual angle was presented in a static surround either with continuous-flash suppression in the dominant eye (CFS condition to make the surround inperceptible or without the suppression (no-CFS condition. The surround stimulus was either a Mondrian or a uniform field of the same mean chromaticity. Stimuli were simulated OSA color chips under red, white (D65, or green illuminant color and were presented on a CRT display. Unique yellows were measured by asking the subjects to judge whether the test stimulus appeared reddish or greenish. Two sizes of the surround stimuli (widths of 1 deg and 4 deg were used. Results showed significant shifts in unique yellow even under the CFS conditions, except for the 1 deg uniform-surround condition. Under the no-CFS condition, the shifts showed remarkable difference between subjects, except for the 4 deg Mondrian-surround condition. Interestingly, trends of the shifts showed high consistency within each subject, across conditions. These results indicate that mechanisms at both higher and lower levels than the neuronal site of interocular suppression are involved, and that the color shifts follow each subject's strategy in the higher-order mechanisms when only insufficient clues are available in the surround to estimate illuminant color.

Confronting, Confirming, and Dispelling Myths Surrounding ERP-in-the-Cloud

DEFF Research Database (Denmark)

Beaulieu, Tanya; C. Martin, Todd; Sarker, Saonee

2015-01-01

on the topic, there is substantial uncertainty surrounding the benefits and challenges of ERP cloud computing. Consequently, as often is the case with new technologies, popular myths surrounding the technology are used to make adoption and implementation decisions. As a first step toward providing an informed...... with stakeholders related to an ERP cloud-based solution. Our results dispel some of the myths, while supporting others, and highlight how ERP vendors work around the different types of challenges surrounding this technology. Our study also helps understand the benefits of ERP cloud computing, and informs about how...

Mass lead intoxication from informal used lead-acid battery recycling in dakar, senegal.

Science.gov (United States)

Haefliger, Pascal; Mathieu-Nolf, Monique; Lociciro, Stephanie; Ndiaye, Cheikh; Coly, Malang; Diouf, Amadou; Faye, Absa Lam; Sow, Aminata; Tempowski, Joanna; Pronczuk, Jenny; Filipe Junior, Antonio Pedro; Bertollini, Roberto; Neira, Maria

2009-10-01

Between November 2007 and March 2008, 18 children died from a rapidly progressive central nervous system disease of unexplained origin in a community involved in the recycling of used lead-acid batteries (ULAB) in the suburbs of Dakar, Senegal. We investigated the cause of these deaths. Because autopsies were not possible, the investigation centered on clinical and laboratory assessments performed on 32 siblings of deceased children and 23 mothers and on 18 children and 8 adults living in the same area, complemented by environmental health investigations. All 81 individuals investigated were poisoned with lead, some of them severely. The blood lead level of the 50 children tested ranged from 39.8 to 613.9 microg/dL with a mean of 129.5 microg/dL. Seventeen children showed severe neurologic features of toxicity. Homes and soil in surrounding areas were heavily contaminated with lead (indoors, up to 14,000 mg/kg; outdoors, up to 302,000 mg/kg) as a result of informal ULAB recycling. Our investigations revealed a mass lead intoxication that occurred through inhalation and ingestion of soil and dust heavily contaminated with lead as a result of informal and unsafe ULAB recycling. Circumstantial evidence suggested that most or all of the 18 deaths were due to encephalopathy resulting from severe lead intoxication. Findings also suggest that most habitants of the contaminated area, estimated at 950, are also likely to be poisoned. This highlights the severe health risks posed by informal ULAB recycling, in particular in developing countries, and emphasizes the need to strengthen national and international efforts to address this global public health problem.

Ecological mechanisms linking protected areas to surrounding lands.

Science.gov (United States)

Hansen, Andrew J; DeFries, Ruth

2007-06-01

Land use is expanding and intensifying in the unprotected lands surrounding many of the world's protected areas. The influence of this land use change on ecological processes is poorly understood. The goal of this paper is to draw on ecological theory to provide a synthetic framework for understanding how land use change around protected areas may alter ecological processes and biodiversity within protected areas and to provide a basis for identifying scientifically based management alternatives. We first present a conceptual model of protected areas embedded within larger ecosystems that often include surrounding human land use. Drawing on case studies in this Invited Feature, we then explore a comprehensive set of ecological mechanisms by which land use on surrounding lands may influence ecological processes and biodiversity within reserves. These mechanisms involve changes in ecosystem size, with implications for minimum dynamic area, species-area effect, and trophic structure; altered flows of materials and disturbances into and out of reserves; effects on crucial habitats for seasonal and migration movements and population source/sink dynamics; and exposure to humans through hunting, poaching, exotics species, and disease. These ecological mechanisms provide a basis for assessing the vulnerability of protected areas to land use. They also suggest criteria for designing regional management to sustain protected areas in the context of surrounding human land use. These design criteria include maximizing the area of functional habitats, identifying and maintaining ecological process zones, maintaining key migration and source habitats, and managing human proximity and edge effects.

Integral measurements of neutron production in spallation targets

International Nuclear Information System (INIS)

Frehaut, J.; Deneuville, D.; Ledoux, X.; Lochard, J.P.; Longuet, J.L.; Petibon, E.; Alrick, K.; Bownan, D.; Cverna, F.; King, N.S.P.; Morgan, G.L.; Greene, G.; Hanson, A.; Snead, L.; Thompson, R.; Ward, T.

1998-01-01

Measurements of neutron production for thick iron, tungsten and lead targets of different diameter prototypic for spallation systems have been made at SATURNE in an incident proton energy range from 400 MeV to 2 GeV. TIERCE code system calculations are in good agreement with experiment for iron and large diameter tungsten and lead targets. They overestimate the measured neutron production for tungsten and lead targets for diameter ≤20 cm. (author)

The nature of surround-induced depolarizing responses in goldfish cones

NARCIS (Netherlands)

Kraaij, D. A.; Spekreijse, H.; Kamermans, M.

2000-01-01

Cones in the vertebrate retina project to horizontal and bipolar cells and the horizontal cells feedback negatively to cones. This organization forms the basis for the center/surround organization of the bipolar cells, a fundamental step in the visual signal processing. Although the surround

Investigation of the readout electronics of DELPHI surround muon chamber

International Nuclear Information System (INIS)

Khovanskij, N.; Krumshtejn, Z.; Ol'shevskij, A.; Sadovskij, A.; Sedykh, Yu.; Molnar, J.; Sicho, P.; Tomsa, Z.

1995-01-01

The characteristics of the readout electronics of the DELPHI surround muon chambers with various AMPLEX chips (AMPLEX 16 and AMPLEX-SICAL) are presented. This electronics is studied in a cosmic rays test of the real surround muon chamber model. 4 refs., 6 figs., 1 tab

Lead accumulation by some plant species cultivated in the vicinity of a lead factory in Sfax; Accumulation du plomb par quelques especes vegetales cultivees au voisinage d'une fonderie de plomb a Sfax

Energy Technology Data Exchange (ETDEWEB)

Elloumi, N.; Ben Abdallah, F.; Mezghani, I.; Boukhris, M. [Faculte des Sciences de Sfax, Lab. d' Ecologie Vegetale, Unite de Recherche Biologie de la Vegetation en Milieu Aride, Sfax (Tunisia)

2003-06-01

Atmospheric emissions, particularly the particles containing high concentrations of heavy metals, have harmful effects on the environment. The aim of this work is to evaluate the accumulation of a lead factory emissions, on the vegetation near the factory in function of time, distance and climatic factors. Analyses results have showed an important lead accumulation by vegetation located in the vicinity of the factory. Plant species studied here (olive trees, palm trees, almond trees, pomegranate trees and vine) have shown high and variable lead accumulation. Highest concentrations (over than 400 {mu}g/g) were recorded in non-washed leaves of olive trees surrounding the factory. Rapid and considerable decrease of lead content was, however, recorded for the same species situated at a distance bigger than 1 km from the source. Interaction effects study of several factors, such as climatic factors and diversity of plant species on lead accumulation by plants, have shown that the degree of lead accumulation was related to wind direction and distance from pollution source. Lead concentrations in species planted in the NW of the factory and exposed to SE wind direction were higher than that of ones exposed to any other direction. High lead concentrations in the vicinity of the factory seem to indicate that particles and gaseous pollutants fallout in the surrounding of the factory are as much important as the chimney height is reduced. (authors)

Outside influence: The sense of agency takes into account what is in our surroundings.

Science.gov (United States)

Hon, Nicholas; Seow, Yin-Yi; Pereira, Don

2018-05-01

We are quite capable of distinguishing those outcomes we cause from those we do not. This ability to sense self-agency is thought to be produced by a comparison between a predictive representation of an outcome and the actual outcome that occurs. It is unclear, though, specifically what types of information can be entered into agency computations. Here, we demonstrate that information from non-target stimuli (stimuli that are not directly acted upon) incidentally present in our surroundings can influence predictions of outcomes, consequently modulating the sense of agency over clearly-defined target outcomes (those that occur to acted-upon stimuli). This provides the first evidence that our sense of agency is contextualized with respect to what is in our immediate visual environment. Furthermore, our data suggest that agency computations, instead of just a single comparison, may involve comparisons performed in stages, with different stages involving different types/classes of information. A model of such multi-stage comparisons is described. Copyright © 2018 Elsevier B.V. All rights reserved.

Measurement of activation reaction rate distribution on a mercury target with a lead-reflector and light-water-moderator for high energy proton bombardment using AGS accelerator

International Nuclear Information System (INIS)

Kasugai, Yoshimi; Takada, Hiroshi; Meigo, Shin-ichiro

2001-02-01

Characteristic of spallation neutrons driven by GeV protons from a mercury target with a lead-reflector and light-water-moderator was studied experimentally using the Alternating Gradient Synchrotron (AGS) facility of Brookhaven National Laboratory in a framework of the ASTE (AGS Spallation Target Experiment) collaboration. Several reaction rates along with the mercury target were measured with the activation method at incident proton energies of 1.94, 12 and 24 GeV. Indium, niobium, aluminum, cobalt, nickel and bismuth were used as activation detectors to cover the threshold energy of between 0.33 and 40.9 MeV. This report summarizes the experimental procedure with all the measured data. (author)

Battery lead recycling and environmental pollution hazards

Energy Technology Data Exchange (ETDEWEB)

Collivignarelli, C; Urbini, G; Riganti, V

1986-01-01

In Italy, lead recycling from discarded electric storage batteries has been developing on an industrial scale, with a yield of approximately 98% and a saving of 37% on lead imports. Moreover, battery plastic coverings can also be profitably recycled. However, the recovery industry has proved to be very polluting, as shown by the recent example of a factory sited in a vast agricultural area south of Milan, Italy. Lead in the atmosphere affects workers exposed to lead concentrations above A.C.G.I.H. standards while lead in wastewaters and fumes from smelting furnaces is the cause of environmental pollution. In particular, pollution over large tracts of cultivated lands surrounding such factories is shown by the considerable quantity of lead in forage which is harmful to cattle fed on it. Tests on dead oxen have revealed lead concentrations in kidneys and liver ranging from 9.1 to 17.4 mg/kg and 6 to 7 mg/kg respectively. Quantities exceeding safety limits have been found also in cattle blood and milk, with maximum values of 51 ..mu..g/100 ml and 0.072 mg/1 respectively. These results prove the need for extremely efficient control systems in this particular recovery industry. (author).

Process of Fragment-Based Lead Discovery—A Perspective from NMR

Directory of Open Access Journals (Sweden)

Rongsheng Ma

2016-07-01

Full Text Available Fragment-based lead discovery (FBLD has proven fruitful during the past two decades for a variety of targets, even challenging protein–protein interaction (PPI systems. Nuclear magnetic resonance (NMR spectroscopy plays a vital role, from initial fragment-based screening to lead generation, because of its power to probe the intrinsically weak interactions between targets and low-molecular-weight fragments. Here, we review the NMR FBLD process from initial library construction to lead generation. We describe technical aspects regarding fragment library design, ligand- and protein-observed screening, and protein–ligand structure model generation. For weak binders, the initial hit-to-lead evolution can be guided by structural information retrieved from NMR spectroscopy, including chemical shift perturbation, transferred pseudocontact shifts, and paramagnetic relaxation enhancement. This perspective examines structure-guided optimization from weak fragment screening hits to potent leads for challenging PPI targets.

CMG helicase and DNA polymerase ε form a functional 15-subunit holoenzyme for eukaryotic leading-strand DNA replication.

Science.gov (United States)

Langston, Lance D; Zhang, Dan; Yurieva, Olga; Georgescu, Roxana E; Finkelstein, Jeff; Yao, Nina Y; Indiani, Chiara; O'Donnell, Mike E

2014-10-28

DNA replication in eukaryotes is asymmetric, with separate DNA polymerases (Pol) dedicated to bulk synthesis of the leading and lagging strands. Pol α/primase initiates primers on both strands that are extended by Pol ε on the leading strand and by Pol δ on the lagging strand. The CMG (Cdc45-MCM-GINS) helicase surrounds the leading strand and is proposed to recruit Pol ε for leading-strand synthesis, but to date a direct interaction between CMG and Pol ε has not been demonstrated. While purifying CMG helicase overexpressed in yeast, we detected a functional complex between CMG and native Pol ε. Using pure CMG and Pol ε, we reconstituted a stable 15-subunit CMG-Pol ε complex and showed that it is a functional polymerase-helicase on a model replication fork in vitro. On its own, the Pol2 catalytic subunit of Pol ε is inefficient in CMG-dependent replication, but addition of the Dpb2 protein subunit of Pol ε, known to bind the Psf1 protein subunit of CMG, allows stable synthesis with CMG. Dpb2 does not affect Pol δ function with CMG, and thus we propose that the connection between Dpb2 and CMG helps to stabilize Pol ε on the leading strand as part of a 15-subunit leading-strand holoenzyme we refer to as CMGE. Direct binding between Pol ε and CMG provides an explanation for specific targeting of Pol ε to the leading strand and provides clear mechanistic evidence for how strand asymmetry is maintained in eukaryotes.

Religion's relationship with social boundaries surrounding gender ...

African Journals Online (AJOL)

Religion's relationship with social boundaries surrounding gender. ... is associated with segregation, marginalization and differentiation between men and women. ... are necessary in the society it should not be mistaken for gender inequality.

Vasculature surrounding a nodule: A novel lung cancer biomarker.

Science.gov (United States)

Wang, Xiaohua; Leader, Joseph K; Wang, Renwei; Wilson, David; Herman, James; Yuan, Jian-Min; Pu, Jiantao

2017-12-01

To investigate whether the vessels surrounding a nodule depicted on non-contrast, low-dose computed tomography (LDCT) can discriminate benign and malignant screen detected nodules. We collected a dataset consisting of LDCT scans acquired on 100 subjects from the Pittsburgh Lung Screening study (PLuSS). Fifty subjects were diagnosed with lung cancer and 50 subjects had suspicious nodules later proven benign. For the lung cancer cases, the location of the malignant nodule in the LDCT scans was known; while for the benign cases, the largest nodule in the LDCT scan was used in the analysis. A computer algorithm was developed to identify surrounding vessels and quantify the number and volume of vessels that were connected or near the nodule. A nonparametric receiver operating characteristic (ROC) analysis was performed based on a single nodule per subject to assess the discriminability of the surrounding vessels to provide a lung cancer diagnosis. Odds ratio (OR) were computed to determine the probability of a nodule being lung cancer based on the vessel features. The areas under the ROC curves (AUCs) for vessel count and vessel volume were 0.722 (95% CI=0.616-0.811, plung cancer group 9.7 (±9.6) compared to the non-lung cancer group 4.0 (±4.3) CONCLUSION: Our preliminary results showed that malignant nodules are often surrounded by more vessels compared to benign nodules, suggesting that the surrounding vessel characteristics could serve as lung cancer biomarker for indeterminate nodules detected during LDCT lung cancer screening using only the information collected during the initial visit. Copyright © 2017 Elsevier B.V. All rights reserved.

Spectrometric gamma investigations concerning zinc-lead ores and the products of their processing

International Nuclear Information System (INIS)

Girczys, J.; Skowronek, J.; Zrodlowski, B.

1983-01-01

Zinc-lead ore and products of its enrichment were investigated using gamma spectrometry for the content of uranium, thorium and potassium 40. It was stated that the mean content of these elements in a deposit does not diverge from their mean concentration in the lithosphere. They also accompany the surrounding rocks. As a result of mechanical processing of this ore radionuclides pass discards in which they do not form concentrations dangerous for life, either. In the exploitation areas and in the surroundings there is no state of ecological hazard. (author)

Assessing Leading ERP-SAP Implementation in Leading Firms in Indonesia

Science.gov (United States)

Syaiful, B.; Gunawan, W.

2017-01-01

Enterprise resource planning (ERP) enables to bring critical capabilities to an organisation, however, the implementation of such capabilities is often surrounded with problems. The implementing ERP-SAP in Indonesian enterprises are still facing tremendous challenges with the failure rate can reach more than 80% of the cases. The article examines the common problems faced by the consultants whenever they deal with their clients, from the practical perspectives. The article takes the multiple case studies of the leading enterprises in Indonesia, such as: KS (largest steel producer), GEM (large mining producer), and HS (large retailer), with the aim to identify the root of problems of SAP implementation. The outcome of the study is expected to provide the consultants with the guideline to understand the ERP implementation process in their clients and effective solutions to cope with it.

Post-irradiation analysis of an ISOLDE lead-bismuth target: Stable and long-lived noble gas nuclides

Energy Technology Data Exchange (ETDEWEB)

Leya, I., E-mail: Ingo.Leya@space.unibe.ch [University of Bern, Space Science and Planetology, Bern (Switzerland); Grimberg, A. [University of Bern, Space Science and Planetology, Bern (Switzerland); Isotope Geochemistry, ETH Zürich, Zürich (Switzerland); David, J.-C. [CEA/Saclay, Irfu/SPhN, 91191 Gif-sur-Yvette, Cedex (France); Schumann, D.; Neuhausen, J. [Paul Scherrer Institut, Villigen (Switzerland); Zanini, L. [Paul Scherrer Institut, Villigen (Switzerland); European Spallation Source ESS AB, P.O. Box 117, SE-22100 Lund (Sweden); Noah, E. [University of Geneva, Département de Physique Nucléaire et Corpusculaire, Geneve (Switzerland)

2016-07-15

We measured the isotopic concentrations of long-lived and stable He, Ne, Ar, Kr, and Xe isotopes in a sample from a lead-bismuth eutectic target irradiated with 1.0 and 1.4 GeV protons. Our data indicate for most noble gases nearly complete release with retention fractions in the range of percent or less. Higher retention fractions result from the decay of long-lived radioactive progenitors from groups 1, 2, or 7 of the periodic table. From the data we can calculate a retention fraction for {sup 3}H of 2–3%. For alkaline metals we find retention fractions of about 10%, 30%, and 50% for Na, Rb, and Cs, respectively. For the alkaline earth metal Ba we found complete retention. Finally, the measured Kr and Xe concentrations indicate that there was some release of the halogens Br and I during and/or after the irradiation.

Numerical investigation of heating of a gold nanoparticle and the surrounding microenvironment by nanosecond laser pulses for nanomedicine applications

International Nuclear Information System (INIS)

Sassaroli, E; Li, K C P; O'Neill, B E

2009-01-01

We have modeled, by finite element analysis, the process of heating of a spherical gold nanoparticle by nanosecond laser pulses and of heat transfer between the particle and the surrounding medium, with no mass transfer. In our analysis, we have included thermal conductivity changes, vapor formation, and changes of the dielectric properties as a function of temperature. We have shown that such changes significantly affect the temperature reached by the particle and surrounding microenvironment and therefore the thermal and dielectric properties of the medium need to be known for a correct determination of the temperature elevation. We have shown that for sufficiently low intensity and long pulses, it is possible to establish a quasi-steady temperature profile in the medium with no vapor formation. As the intensity is increased, a phase-change with vapor formation takes place around the gold nanoparticle. As phase-transition starts, an additional increase in the intensity does not significantly increase the temperature of the gold nanoparticle and surrounding environment. The temperature starts to rise again above a given intensity threshold which is particle and environment dependent. The aim of this study is to provide useful insights for the development of molecular targeting of gold nanoparticles for applications such as remote drug release of therapeutics and photothermal cancer therapy.

Numerical investigation of heating of a gold nanoparticle and the surrounding microenvironment by nanosecond laser pulses for nanomedicine applications

Energy Technology Data Exchange (ETDEWEB)

Sassaroli, E; Li, K C P; O' Neill, B E [Department of Radiology, Methodist Hospital Research Institute, Houston, TX, 77030 (United States)], E-mail: beoneill@tmhs.org

2009-09-21

We have modeled, by finite element analysis, the process of heating of a spherical gold nanoparticle by nanosecond laser pulses and of heat transfer between the particle and the surrounding medium, with no mass transfer. In our analysis, we have included thermal conductivity changes, vapor formation, and changes of the dielectric properties as a function of temperature. We have shown that such changes significantly affect the temperature reached by the particle and surrounding microenvironment and therefore the thermal and dielectric properties of the medium need to be known for a correct determination of the temperature elevation. We have shown that for sufficiently low intensity and long pulses, it is possible to establish a quasi-steady temperature profile in the medium with no vapor formation. As the intensity is increased, a phase-change with vapor formation takes place around the gold nanoparticle. As phase-transition starts, an additional increase in the intensity does not significantly increase the temperature of the gold nanoparticle and surrounding environment. The temperature starts to rise again above a given intensity threshold which is particle and environment dependent. The aim of this study is to provide useful insights for the development of molecular targeting of gold nanoparticles for applications such as remote drug release of therapeutics and photothermal cancer therapy.

Childhood Suicide and Myths Surrounding It.

Science.gov (United States)

Greene, Dorothea B.

1994-01-01

Dispels five misconceptions surrounding the suicide of children: that children under the age of six do not commit suicide; that suicide in latency years is extremely rare; that psychodynamically and developmentally true depression is not possible in childhood; that child cannot understand finality of death; and that children are cognitively and…

Vaporization of elemental mercury from pools of molten lead at low concentrations

International Nuclear Information System (INIS)

Greene, G.A.; Finfrock, C.C.

2000-01-01

Should coolant accidentally be lost to the APT (Accelerator Production of Tritium) blanket and target, and the decay heat in the target be deposited in the surrounding blanket by thermal radiation, temperatures in the blanket modules could exceed structural limits and cause a physical collapse of the blanket modules into a non-coolable geometry. Such a sequence of unmitigated events could result in some melting of the APT blanket and create the potential for the release of mercury into the target-blanket cavity air space. Experiments were conducted which simulate such hypothetical accident conditions in order to measure the rate of vaporization of elemental mercury from pools of molten lead to quantify the possible severe accident source term for the APT blanket region. Molten pools of from 0.01% to 0.10% mercury in lead were prepared under inert conditions. Experiments were conducted, which varied in duration from several hours to as long as a month, to measure the mercury vaporization from the lead pools. The melt pools and gas atmospheres were held fixed at 340 C during the tests. Parameters which were varied in the tests included the mercury concentration, gas flow rate over the melt and agitation of the melt, gas atmosphere composition and the addition of aluminum to the melt. The vaporization of mercury was found to scale roughly linearly with the concentration of mercury in the pool. Variations in the gas flow rates were not found to have any effect on the mass transfer, however agitation of the melt by a submerged stirrer did enhance the mercury vaporization rate. The rate of mercury vaporization with an argon (inert) atmosphere was found to exceed that for an air (oxidizing) atmosphere by as much as a factor of from ten to 20; the causal factor in this variation was the formation of an oxide layer over the melt pool with the air atmosphere which served to retard mass transfer across the melt-atmosphere interface. Aluminum was introduced into the melt to

Blood Lead Levels in Children and Environmental Lead Contamination in Miami Inner City, Florida

Directory of Open Access Journals (Sweden)

Theophile Niyonsenga

2006-09-01

Full Text Available Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL as low as 10 μg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 μg /dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 μg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p < 0.05. However, the correlations between BLL and the soil, air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami.

Lead exposure and biological effects in pied flycatchers (Ficedula hypoleuca) before and after the closure of a lead mine in northern Sweden

International Nuclear Information System (INIS)

Berglund, A.M.M.; Ingvarsson, P.K.; Danielsson, H.; Nyholm, N.E.I.

2010-01-01

Mining activities affect the surrounding environment by increasing exposure to metals. In this study, metal accumulation and its effects on reproduction and health of pied flycatcher (Ficedula hypoleuca) nestlings were monitored before and up to five years after a lead mine and enrichment plant closed down. The lead concentration in moss, nestling blood, liver and feces all indicated decreased lead exposure by at least 31% after closure, although only blood lead decreased significantly. Although the birds responded fairly well to the changed atmospheric deposition (based on moss samples), concentrations were still higher compared with birds in a reference area, and breeding was affected at the mine (smaller clutches and higher mortality). Surviving nestlings suffered from lower hemoglobin levels, mean cell hemoglobin concentrations and inhibited δ-aminolevulinic acid dehydratase activity. Lead poisoning contributed to poor health and adverse reproductive effects, but other factors (e.g. increased parasitic load) probably also affected the birds. - Increased mortality and lower blood values in pied flycatcher (Ficedula hypoleuca) nestlings near a closed lead mine.

Lead pollution of road-side vegetation

Energy Technology Data Exchange (ETDEWEB)

Quinche, J P; Zuber, R; Bovay, E

1969-01-01

In Switzerland, investigations have been made in 1967/1968 concerning the distribution of lead issued from the antiknocking additive of petrol. Observations show that the deposits in meadows in the immediate surrounding (first meter) of roads and highways with high traffic density were especially high (50-100 ppm in dry matter). The pollution is still perceptible even as far as 50 meters from the road. Moreover, during the summer (July and August), a second zone of high lead accumulation (more than 100 ppm) was detected 50 to 100 m from the road, particularly along the highways. This probably is caused by certain climatic conditions and the increase of traffic volume. With regard to fruits, only the downy species (e.g. apricots, peaches) retain some quantities of lead on their skin. Vegetables with large leaves, e.g. lettuce, spinach, and particularly vegetables with definite dissected foliage, such as fennel and parsley, may accumulate relatively high quantities of lead. According to some authors, up to 50 percent of these deposits may be eliminated by washing with water. Conversely, root vegetables (e.g. carrots, onions) do not show a perceptible lead contamination. Likewise the flesh of fruits is not markedly polluted by lead. Trials with foddering milk cows using hay harvested along a highway are not yet analyzed. The results from these trials should permit determining the proportion of lead which remains in the tissues (meat etc.) or passes over into the milk.

Materials considerations in accelerator targets

International Nuclear Information System (INIS)

Peacock, H.B. Jr.; Iyer, N.C.; Louthan, M.R. Jr.

1994-01-01

Future nuclear materials production and/or the burn-up of long lived radioisotopes may be accomplished through the capture of spallation produced neutrons in accelerators. Aluminum clad-lead and/or lead alloys has been proposed as a spallation target. Aluminum was the cladding choice because of the low neutron absorption cross section, fast radioactivity decay, high thermal conductivity, and excellent fabricability. Metallic lead and lead oxide powders were considered for the target core with the fabrication options being casting or powder metallurgy (PM). Scoping tests to evaluate gravity casting, squeeze casting, and casting and swaging processes showed that, based on fabricability and heat transfer considerations, squeeze casting was the preferred option for manufacture of targets with initial core cladding contact. Thousands of aluminum clad aluminum-lithium alloy core targets and control rods for tritium production have been fabricated by coextrusion processes and successfully irradiated in the SRS reactors. Tritium retention in, and release from the coextruded product was modeled from experimental and operational data. Newly produced tritium atoms were trapped by lithium atoms to form a lithium tritide. The effective tritium pressure required for trap or tritide stability was the equilibrium decomposition pressure of tritium over a lithium tritide-aluminum mixture. The temperature dependence of tritium release was determined by the permeability of the cladding to tritium and the local equilibrium at the trap sites. The model can be used to calculate tritium release from aluminum clad, aluminum-lithium alloy targets during postulated accelerator operational and accident conditions. This paper describes the manufacturing technologies evaluated and presents the model for tritium retention in aluminum clad, aluminum-lithium alloy tritium production targets

Fabrication and characterization of cryogenic targets for inertial confinement fusion

International Nuclear Information System (INIS)

Rieger, H.; Kim, K.

1979-08-01

A new technique has been developed which is capable of fabricating uniform cryogenic targets for use in inertial confinement fusion. The essence of the technique is to directly wet a target with a cold helium gas jet, which results in freezing of the DT mixture contained in the target. A controlled amount of current is pulsed through a heater wire surrounding the target, giving rise to fast evaporation and refreezing of the DT-condensate into a uniform layer. Experiments, which have been performed with D 2 -filled glass microshells, successfully produce uniform layers of both liquid and solid D 2 inside the glass shells. A set of data illustrating the technique is presented and analyzed

Minimal invasive epicardial lead implantation: optimizing cardiac resynchronization with a new mapping device for epicardial lead placement.

Science.gov (United States)

Maessen, J G; Phelps, B; Dekker, A L A J; Dijkman, B

2004-05-01

To optimize resynchronization in biventricular pacing with epicardial leads, mapping to determine the best pacing site, is a prerequisite. A port access surgical mapping technique was developed that allowed multiple pace site selection and reproducible lead evaluation and implantation. Pressure-volume loops analysis was used for real time guidance in targeting epicardial lead placement. Even the smallest changes in lead position revealed significantly different functional results. Optimizing the pacing site with this technique allowed functional improvement up to 40% versus random pace site selection.

Transmutation of $^{239}$Pu and Other Nuclides Using Spallation Neutrons Produced by Relativistic Protons Reacting with Massive U- and Pb-Targets

CERN Document Server

Adam, J; Bamblevski, V P; Barabanov, M Yu; Bradnova, V; Chaloun, P; Hella, K M; Kalinnikov, V G; Krivopustov, M I; Kulakov, B A; Perelygin, V P; Pronskikh, V S; Pavliouk, A V; Solnyshkin, A A; Sosnin, A N; Stegailov, V I; Tsoupko-Sitnikov, V M; Zaverioukha, O S; Adloff, J C; Debeauvais, M; Brandt, R; Langrock, E J; Vater, P; Van, J S; Westmeier, W; Dwivedi, K K; Guo Shi Lun; Li Li Qiang; Hashemi-Nezhad, S R; Kievets, M K; Lomonosova, E M; Zhuk, I V; Modolo, G; Odoj, R; Zamani-Valassiadou, M

2001-01-01

Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as ^{129}I, ^{237}Np, and ^{239}Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory for High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV\\le E(p)\\le 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminum containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or "energy amplifier") using a 10 mA pr...

DETERMINATION OF ZINC AND LEAD IN SURROUNDING WATER ...

African Journals Online (AJOL)

userpc

Bayero Journal of Pure and Applied Sciences, 10(1): 107 - 111. ISSN 2006 – 6996 ... manage and preserve the pond as it serve as ecological “laboratory” for scientific research. Keywords: ..... Bhadra River, Karnataka International. Journal of ...

Modifications of center-surround, spot detection and dot-pattern selective operators

NARCIS (Netherlands)

Petkov, Nicolai; Visser, Wicher T.

2005-01-01

This paper describes modifications of the models of center-surround and dot-pattern selective cells proposed previously. These modifications concern mainly the normalization of the difference of Gaussians (DoG) function used to model center-surround receptive fields, the normalization of

Surrounding rock stress analysis of underground high level waste repository

International Nuclear Information System (INIS)

Liu Wengang; Wang Ju; Wang Guangdi

2006-01-01

During decay of nuclear waste, enormous energy was released, which results in temperature change of surrounding rock of depository. Thermal stress was produced because thermal expansion of rock was controlled. Internal structure of surrounding rock was damaged and strength of rock was weakened. So, variation of stress was a dynamic process with the variation of temperature. BeiShan region of Gansu province was determined to be the depository field in the future, it is essential to make research on granite in this region. In the process of experiment, basic physical parameters of granite were analyzed preliminary with MTS. Long range temperature and stress filed was simulated considering the damage effect of surrounding rock, and rules of temperature and stress was achieved. (authors)

Smart Chips for Smart Surroundings -- 4S

NARCIS (Netherlands)

Schuler, Eberhard; König, Ralf; Becker, Jürgen; Rauwerda, G.K.; van de Burgwal, M.D.; Smit, Gerardus Johannes Maria; Cardoso, João M.P.; Hübner, Michael

2011-01-01

The overall mission of the 4S project (Smart Chips for Smart Surroundings) was to define and develop efficient flexible, reconfigurable core building blocks, including the supporting tools, for future Ambient System Devices. Reconfigurability offers the needed flexibility and adaptability, it

Advisory group meeting on design and performance of reactor and subcritical blanket systems with lead and lead-bismuth as coolant and/or target material. Working material

International Nuclear Information System (INIS)

2001-01-01

The purpose of the IAEA Advisory Group Meeting (AGM) on Design and Performance of Reactor and Sub-critical Blanket Systems with Lead and Lead-Bismuth as Coolant and/or Target Material was to provide a forum for international information exchange on all the topics relevant to Pb and Pb/Bi cooled critical and sub-critical reactors. In addition, the AGM aimed at: (1) finding ways and means to improve international co-ordination efforts in this area; (2) obtaining advice from the Member States with regard to the activities to be implemented in this area by the IAEA, in order to best meet their needs; and (3) laying out the plans for an effective co-ordination and support of the R and D activities in this area. The AGM stressed that nuclear energy is a realistic solution to satisfy the energy demand, considering the limited resources of fossil fuel, its uneven distribution in the world and the impact of its use on the planet, and taking into account the expected doubling of the world population in the 21st century and tripling of the electricity demand (especially in the developing countries). However, the AGM concluded that the development of an innovative nuclear technology meeting the following requirements must be pursued: (a) deterministic exclusion of any severe accident; (b) proliferation resistance; (c) cost competitiveness with alternative energy sources; (d) sustainable fuel supply; and (e) solution of the radioactive waste management problem

Study of preshower in the PANDA target spectrometer

International Nuclear Information System (INIS)

Dutta, Kamal; Kalita, Kushal; Suzuki, K.; Steinschaden, D.; Roy, B.J.

2015-01-01

PANDA (antiProton ANnihilation at DArmstdt) is one of the major projects at FAIR, GSI, Germany. The main objective of this experiment is to study the fundamental questions of hadron physics and QCD in pp¯ annihilation using high intensity cooled anti-proton beams with momenta between 1.5 GeV/c and 15 GeV/c. To achieve high momentum resolution and full solid angle coverage, the PANDA detector is split in to two parts: target spectrometer and forward spectrometer. The target spectrometer is a complex detector consisting of several subsystems surrounding the interaction point. It is surrounded by a 2 T superconducting solenoid magnet. A Micro Vertex Detector (MVD), close to interaction point, detects secondary vertices of D and Hyperon decays. The Straw Tube Tracker (STT) is the central tracking system around the MVD. A cherenkov counter named DIRC (Detection of Internally Reflected Cherenkov light), provides π/K separation for particle momenta up to 3.5 GeV/c. The barrel Time-of-Flight (TOF) detector, consists of plastic scintillator tiles with a time resolution of 100 ps. It is used to identify particles of momentum below cherenkov threshold

Investigation and Evaluation of Children’s Blood Lead Levels around a Lead Battery Factory and Influencing Factors

Directory of Open Access Journals (Sweden)

Feng Zhang

2016-05-01

Full Text Available Lead pollution incidents have occurred frequently in mainland China, which has caused many lead poisoning incidents. This paper took a battery recycling factory as the subject, and focused on measuring the blood lead levels of environmental samples and all the children living around the factory, and analyzed the relationship between them. We collected blood samples from the surrounding residential area, as well as soil, water, vegetables. The atomic absorption method was applied to measure the lead content in these samples. The basic information of the generation procedure, operation type, habit and personal protect equipment was collected by an occupational hygiene investigation. Blood lead levels in 43.12% of the subjects exceeded 100 μg/L. The 50th and the 95th percentiles were 89 μg/L and 232 μg/L for blood lead levels in children, respectively, and the geometric mean was 94 μg/L. Children were stratified into groups by age, gender, parents’ occupation, distance and direction from the recycling plant. The difference of blood lead levels between groups was significant (p < 0.05. Four risk factors for elevated blood lead levels were found by logistic regression analysis, including younger age, male, shorter distance from the recycling plant, and parents with at least one working in the recycling plant. The rate of excess lead concentration in water was 6.25%, 6.06% in soil and 44.44% in leaf vegetables, which were all higher than the Chinese environment standards. The shorter the distance to the factory, the higher the value of BLL and lead levels in vegetable and environment samples. The lead level in the environmental samples was higher downwind of the recycling plant.

Engineering design of the EURISOL multi-MW spallation target

CERN Document Server

Herrera-Martínez, A; Ashrafi-Nik, M; Samec, K; Freibergs, J; Platacis, E

2007-01-01

The European Isotope Separation On-Line Radioactive Ion Beam project (EURISOL) is set to design the 'next-generation' European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, four target stations are foreseen, three direct targets of approximately 100 kW of beam power and one multi-MW target assembly, all driven by a high-power particle accelerator. In this high power target station, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source. This article summarises the work carried out within Task 2 of the EURISOL Design Study, with special attention to the coupled neutronics of the mercury proton-to-neutron converter and the fission targets. The overall performance of the facility, which will sustain fast neutron fluxes of the order of 1...

ENGINEERING DESIGN OF THE EURISOL MULTI-MW SPALLATION TARGET

CERN Document Server

Adonai Herrera-Martinez*, Yacine Kadi, Morteza Ashrafi-Nik, Karel Samec, Janis Freibergs, Ernests Platacis

The European Isotope Separation On-Line Radioactive Ion Beam project (EURISOL) is set to design the ‘next-generation’ European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, four target stations are foreseen, three direct targets of approximately 100 kW of beam power and one multi-MW target assembly, all driven by a high-power particle accelerator. In this high power target station, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source. This article summarises the work carried out within Task 2 of the EURISOL Design Study, with special attention to the coupled neutronics of the mercury proton-to-neutron converter and the fission targets. The overall performance of the facility, which will sustain fast neutron fluxes of the order ...

Improved laser-to-proton conversion efficiency in isolated reduced mass targets

Energy Technology Data Exchange (ETDEWEB)

Morace, A. [Center for Energy Research, University of California, 9500 Gilman Drive, La Jolla, California 92093 (United States); Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy); Bellei, C.; Patel, P. K. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Bartal, T.; Kim, J.; Beg, F. N. [Center for Energy Research, University of California, 9500 Gilman Drive, La Jolla, California 92093 (United States); Willingale, L.; Maksimchuk, A.; Krushelnick, K. [University of Michigan, 2200 Bonisteel Blvd. Ann Arbor, Michigan 48109 (United States); Wei, M. S. [Center for Energy Research, University of California, 9500 Gilman Drive, La Jolla, California 92093 (United States); General Atomics, 3550 General Atomics Court, San Diego, California 92121 (United States); Batani, D. [Univ. Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, F-33405 Talence (France); Piovella, N. [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy); Stephens, R. B. [General Atomics, 3550 General Atomics Court, San Diego, California 92121 (United States)

2013-07-29

We present experimental results of laser-to-proton conversion efficiency as a function of lateral confinement of the refluxing electrons. Experiments were carried out using the T-Cubed laser at the Center for Ultrafast Optical Science, University of Michigan. We demonstrate that the laser-to-proton conversion efficiency increases by 50% with increased confinement of the target from surroundings with respect to a flat target of the same thickness. Three-dimensional hybrid particle-in-cell simulations using LSP code agree with the experimental data. The adopted target design is suitable for high repetition rate operation as well as for Inertial Confinement Fusion applications.

Target Localization with a Single Antenna via Directional Multipath Exploitation

Directory of Open Access Journals (Sweden)

Ali H. Muqaibel

2015-01-01

Full Text Available Target localization in urban sensing can benefit from angle dependency of the pulse shape at a radar receiver antenna. We propose a localization approach that utilizes the embedded directivity in ultra-wideband (UWB antennas to estimate target positions. A single radar unit sensing operation of indoor targets surrounded by interior walls is considered, where interior wall multipaths are exploited to provide target cross-range. This exploitation assumes resolvability of the multipath components, which is made possible by the virtue of using UWB radar signals. The proposed approach is most attractive when only few multipaths are detectable due to propagation obstructions or owing to low signal-to-noise ratios. Both simulated and experimental data are used to demonstrate the effectiveness of the proposed approach.

Review and research analysis of computational target methods using BioRuby and in silico screening of herbal lead compounds against pancreatic cancer using R programming.

Science.gov (United States)

Jayadeepa, R M; Ray, Ankita; Naik, Dhaval; Sanyal, Debendra Nath; Shah, Disha

2014-01-01

Plants and their natural components sophisticated with the cornerstone of traditional conventional medicinal system throughout the globe for many years and extend to furnish mankind with latest remedies. Natural Products act as lead molecules for the synthesis of various potent drugs. In the current research a study is conducted on herbal small molecule and their potential binding chemical affinity to the effect or molecules of major diseases such as pancreatic cancer. Clinical studies demonstrate correlation between Cyclin- Dependent Kinase 4 (CDK4) and malignant progression of Pancreatic Cancer. Using Bioruby Gem's we were able to analyze better characteristics of the target protein. VegaZZ and NAMD were used to minimize the energy of the target protein. Therefore identification of effective, well- tolerated targets was analyzed. Further the target protein was subjected to docking with the anti cancer inhibitors which represents a rational chemo preventive strategy using AutoDock Vina. Later using the dock score top ranked phytochemicals were analyzed for Toxicity Analysis. Using the BioRuby gem we were able to measure the distance between the amino acid. Various R scripting libraries were used to hunt the best leads, as in this case the phytochemicals. Phytochemicals such as Wedelolactones and Catechin were analyzed computationally. This study has presented the various effects of naturally occurring anti pancreatic cancer compounds Catechin, Wedelolactones that inhibits Cyclin Dependent Kinase 4. The study results reveal that compounds use less binding energy to CDK4 and inhibit its activity. Future investigation of other various wet lab studies such as cell line studies will confirm results of these two herbal chemical formulations potential ones for treating Pancreatic Cancer.

Soil contamination from lead battery manufacturing and recycling in seven African countries.

Science.gov (United States)

Gottesfeld, Perry; Were, Faridah Hussein; Adogame, Leslie; Gharbi, Semia; San, Dalila; Nota, Manti Michael; Kuepouo, Gilbert

2018-02-01

Lead battery recycling is a growing hazardous industry throughout Africa. We investigated potential soil contamination inside and outside formal sector recycling plants in seven countries. We collected 118 soil samples at 15 recycling plants and one battery manufacturing site and analyzed them for total lead. Lead levels in soils ranged from battery industry in Africa continues to expand, it is expected that the number and size of lead battery recycling plants will grow to meet the forecasted demand. There is an immediate need to address ongoing exposures in surrounding communities, emissions from this industry and to regulate site closure financing procedures to ensure that we do not leave behind a legacy of lead contamination that will impact millions in communities throughout Africa. Copyright © 2017 Elsevier Inc. All rights reserved.

Targeted deletion of kidney glucose-6 phosphatase leads to nephropathy

NARCIS (Netherlands)

Clar, Julie; Gri, Blandine; Calderaro, Julien; Birling, Marie-Christine; Herault, Yann; Smit, G. Peter A.; Mithieux, Gilles; Rajas, Fabienne

2014-01-01

Renal failure is a major complication that arises with aging in glycogen storage disease type 1a and type 1b patients. In the kidneys, glucose-6 phosphatase catalytic subunit (encoded by G6pc) deficiency leads to the accumulation of glycogen, an effect resulting in marked nephromegaly and

Strategic Targeted Advertising and Market Fragmentation

OpenAIRE

Lola Esteban; Jose M. Hernandez

2007-01-01

This paper proves that oligopolistic price competition with both targeted advertising and targeted prices can lead to a permanent fragmentation of the market into a local monopoly. However, compared to mass advertising, targeting increases social welfare and turns out to be more beneficial for consumers than for firms.

Handbook on lead-bismuth eutectic alloy and lead properties, materials compatibility, thermal-hydraulics and technologies

International Nuclear Information System (INIS)

2007-01-01

As part of the development of advanced nuclear systems, including accelerator-driven systems (ADS) proposed for high-level radioactive waste transmutation and generation IV reactors, heavy liquid metals such as lead (Pb) or lead-bismuth eutectic (LBE) are under evaluation as reactor core coolant and ADS neutron target material. Heavy liquid metals are also being envisaged as target materials for high-power neutron spallation sources. The objective of this handbook is to collate and publish properties and experimental results on Pb and LBE in a consistent format in order to provide designers with a single source of qualified properties and data and to guide subsequent development efforts. The handbook covers liquid Pb and LBE properties, materials compatibility and testing issues, key aspects of the thermal-hydraulics and system technologies, existing test facilities, open issues and perspectives. (author)

Enhanced sources of acoustic power surrounding AR 11429

International Nuclear Information System (INIS)

Donea, Alina; Hanson, Christopher

2013-01-01

Multi-frequency power maps of the local acoustic oscillations show acoustic enhancements (''acoustic-power halos'') at high frequencies surrounding large active region. Computational seismic holography reveals a high-frequency ''acoustic-emission halo'', or ''seismic glory'' surrounding large active regions. In this study, we have applied computational seismic holography to map the seismic seismic source density surrounding AR 11429. Studies of HMI/SDO Doppler data, shows that the ''acoustic halos'' and the ''seismic glories'' are prominent at high frequencies 5–8 mHz. We investigate morphological properties of acoustic-power and acoustic emission halos around an active region to see if they are spatially correlated. Details about the local magnetic field from vectormagnetograms of AR 11429 are included. We identify a 15'' region of seismic deficit power (dark moat) shielding the white-light boundary of the active region. The size of the seismic moat is related to region of intermediate magnetic field strength. The acoustic moat is circled by the halo of enhanced seismic amplitude as well as enhanced seismic emission. Overall, the results suggest that features are related. However, if we narrow the frequency band to 5.5 – 6.5 mHz, we find that the seismic source density dominates over the local acoustic power, suggesting the existence of sources that emit more energy downward into the solar interior than upward toward the solar surface.

Design of the FMIT lithium target

International Nuclear Information System (INIS)

Hassberger, J.A.; Annese, C.E.; Greenwell, R.K.; Ingham, J.G.; Miles, R.R.; Miller, W.C.

1981-01-01

Development of the liquid lithium target for the Fusion Materials Irradiation Test (FMIT) Facility is described. The target concept, major design goals and design requirements are presented. Progress made in the research and development areas leading to detailed design of the target is discussed. This progress, including experimental and analytic results, demonstrates that the FMIT target design is capable of meeting its major design goals and requirements

Laser-assisted lead extraction: the European experience.

Science.gov (United States)

Kennergren, C; Bucknall, C A; Butter, C; Charles, R; Fuhrer, J; Grosfeld, M; Tavernier, R; Morgado, T B; Mortensen, P; Paul, V; Richter, P; Schwartz, T; Wellens, F

2007-08-01

The aim of this study is to investigate the safety and effectiveness of Excimer laser-assisted lead extraction in Europe. The final European multi-centre study experience is presented. The Excimer is a cool cutting laser (50 degrees C) with a wavelength of 308 nm. The energy is emitted from the tip of a flexible sheath and is absorbed by proteins and lipids, 64% of the energy is absorbed at a tissue depth of 0.06 mm. The sheath is positioned over the lead, and the fibrosis surrounding the lead is vaporized while advancing the sheath without damaging other leads. From August 1996 to March 2001, 383 leads (170 atrial, 213 ventricular) in 292 patients (mean age 61.6 years, range 13-96) were extracted at 14 European centres. Mean implantation time was 74 months (3-358). Most frequent indications were pocket infection (26%), non-functional leads (21%), patient morbidity (21%), septicaemia or endocarditis (14%), erosion (5%), and lead interference (8%). Median extraction time was 15 min (1-300). Complete extraction was achieved in 90.9% of the leads and partial extraction in 3.4%. Extraction failed in 5.7% of the leads. Major complications = perforations caused 10/22 (3.4/5.7%) of the failures. Most partially extracted patients were considered clinically successful, as only minor lead parts without clinical significance were left. Femoral non-laser technique was used to remove 8/12 of the non-complication failures. The total complication rate, including five minor complications (1.7%), was 5.1%. No in-hospital mortality occurred. Pacing and implantable cardioverter-defibrillator leads can safely, effectively, and predictably be extracted. Open-heart extractions can be limited to special cases. The results indicate that the traditional policy of abandoning redundant leads, instead of removing them, may be obsolete in many patients.

Protein Targeting: ER Leads the Way to the Inner Nuclear Envelope.

Science.gov (United States)

Blackstone, Craig

2017-12-04

Efficient targeting of newly synthesized membrane proteins from the endoplasmic reticulum to the inner nuclear membrane depends on nucleotide hydrolysis. A new study shows that this dependence reflects critical actions of the atlastin family of GTPases in maintaining the morphology of the endoplasmic reticulum network. Published by Elsevier Ltd.

[An epidemiological survey on saturnism among children due to lead pollution released from township enterprise].

Science.gov (United States)

Li, Heng-xin; Song, Ya-li; Li, Hong-guang; Yuan, Yong-xin; Xu, Qing; Liu, En-xu; Li, Jin-song

2008-03-01

To understand the current situations of saturnism and blood lead levels of children resided in village and circumjacent areas, and to know its relations with sex, age and other factors on children' s health as to providing some evidences for prevention and control. An epidemiological survey was conducted for finding out the pollution sources and for a better understanding of the surrounding environment. All 221 children under 14 years old, from the lead pollution villages and surrounding establishments were enrolled, and their blood lead levels were detected by graphite atomizer absorption spectrophotometer method. Symptoms of the saturnism were investigated through a standardized questionnaire. SPSS13.0 software was administrated for data analysis. High blood lead level identification rate was 66.06% (146/221), and saturnism rate 32.13% (71/221). The children's blood lead levels among group 1, group 2, group 3 in this village and jade factory were (161.20 +/- 32.94), (176.60 +/- 43.62), (258.00 +/-106.08) and (238.01 +/- 55.20) microg/L respectively and the significant differences were observed through Kruskal-Wallis test (chi2 = 51.84, df= 3, Plead levels of children from group 3 in this village and the jade factory were higher than those of other two groups. No correlation was found between children's age and blood lead level (r = 0.10, P = 0.13). There was a significant difference in blood lead levels between boys and girls (t' = 3.83, Plead levels rising, the occurrence rate of main saturnism symptoms was significantly increased. This survey suggested that the pollution source was a coarse lead smelter. The blood lead level should ke overwhelmingly increased among children who live nearby the higher level of lead blood, that living nearby the lead smeltery,might result in stautnism and negative effect on children's healthy.

Materials considerations in accelerator targets

International Nuclear Information System (INIS)

Peacock, H. B. Jr.; Iyer, N. C.; Louthan, M. R. Jr.

1995-01-01

Future nuclear materials production and/or the burn-up of long lived radioisotopes may be accomplished through the capture of spallation produced neutrons in accelerators. Aluminum clad-lead and/or lead alloys has been proposed as a spallation target. Aluminum was the cladding choice because of the low neutron absorption cross section, fast radioactivity decay, high thermal conductivity, and excellent fabricability. Metallic lead and lead oxide powders were considered for the target core with the fabrication options being casting or powder metallurgy (PM). Scoping tests to evaluate gravity casting, squeeze casting, and casting and swaging processes showed that, based on fabricability and heat transfer considerations, squeeze casting was the preferred option for manufacture of targets with initial core cladding contact. Thousands of aluminum clad aluminum-lithium alloy core targets and control rods for tritium production have been fabricated by coextrusion processes and successfully irradiated in the SRS reactors. Tritium retention in, and release from, the coextruded product was modeled from experimental and operational data. The model assumed that tritium atoms, formed by the 6Li(n,a)3He reaction, were produced in solid solution in the Al-Li alloy. Because of the low solubility of hydrogen isotopes in aluminum alloys, the irradiated Al-Li rapidly became supersaturated in tritium. Newly produced tritium atoms were trapped by lithium atoms to form a lithium tritide. The effective tritium pressure required for trap or tritide stability was the equilibrium decomposition pressure of tritium over a lithium tritide-aluminum mixture. The temperature dependence of tritium release was determined by the permeability of the cladding to tritium and the local equilibrium at the trap sites. The model can be used to calculate tritium release from aluminum clad, aluminum-lithium alloy targets during postulated accelerator operational and accident conditions. This paper describes

Community composition of target vs. non-target fungi in fungicide treated wheat

DEFF Research Database (Denmark)

Knorr, Kamilla; Jørgensen, Lise Nistrup; Justesen, Annemarie Fejer

2012-01-01

disease in wheat and within the last decade, new aggressive strains of yellow rust has caused severe epidemics that lead to substantial yield losses. This study explored the community composition of target versus non-target fungi in yellow rust infected wheat as affected by treatment timing and dose......Fungicide treatments are common control strategies used to manage fungal pathogens in agricultural fields, however, effects of treatments on the composition of total fungal communities, including non-target fungi, in the phyllosphere is not well known. Yellow rust (Puccinia striiformis) is a common...

High Burden of Subclinical Lead Toxicity after Phase Out of Lead from Petroleum in Pakistan.

Science.gov (United States)

Majid, Hafsa; Khan, Aysha Habib; Khan, Nadeem Ullah; Siddiqui, Imran; Ghani, Farooq; Jafri, Lena

2017-12-01

To evaluate the frequency of subclinical lead toxicity. Cross-sectional study. Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Karachi, from January 2011 to December 2014. Analysis of laboratory data for blood lead levels (BLL) was performed. Lead was tested by atomic absorption spectrometer. For all subjects, only initial test results were included while the results of repeated testing were excluded. Exemption was sought from institutional ethical review committee. BLL of 2-10 ug/dl and 10-70 ug/dl in children and adults, respectively were taken as subclinical lead toxicity. Amongst the total number of subjects tested (n=524), 26.5% (n=139) were children (lead level 16.9 ug/dl (36.1-4)] and lower level [4.2 ug/dl (6.8-2.6)] in children with lead levels while most had either subclinical (76%, n=106) or toxic lead levels (8%, n=11). In adults, (55%, n=212) subjects had desired lead levels, and 40% (n=154) and 4.99% (n=19) had subclinical and toxic lead levels. Presence of subclinical lead poisoning even after phasing out of lead petroleum in Pakistanis is alarming, especially in children. A national population-based study to determine the lead status and targeted intervention to identify potential sources is need of the time.

Leading practice water monitoring in northern Australia

International Nuclear Information System (INIS)

Bush, M.; Turner, K.

2010-01-01

Ranger Uranium Mine is undergoing an environmental impact statement assessment process to develop a Heap Leach facility to treat low grade ore on site. The facility is proposed to be located in the relatively unimpacted Gulungul catchment within the Ranger Project Area which itself is surrounded by, but excluded from, the World Heritage listed Kakadu National Park. The Supervising Scientist Division (SSD) acts to ensure the downstream environment is protected from mine-related impacts. To achieve this SSD will develop a leading practice monitoring program for Gulungul Creek to monitor potential impacts to this catchment from the Heap Leach facility. (author)

Opportunity's Surroundings on Sol 1818

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

Tunneling nanotubes: A versatile target for cancer therapy.

Science.gov (United States)

Sahoo, Pragyaparamita; Jena, Soumya Ranjan; Samanta, Luna

2017-11-29

Currently Cancer is the leading cause of death worldwide. Malignancy or cancer is a class of diseases characterized by uncontrolled cell growth that eventually invade other tissues and dvelop secondary malignant growth at other sites by metastasis. Intercellular communication plays a major in cancer, particularly in the process of cell proliferation and coordination which in turn leads to tumor invasion, metastasis and development of resistance to therapy. Cells communicate among themselves in a variety of ways, namely, i) via gap junctions with adjacent cells, ii) via exosomes with nearby cells and iii) via chemical messengers with distant cells. Besides, cell - cell connection by tunneling nanotubes (TnTs) is recently gaining importance where intercellular components are transferred between cells. In general cell organelles like Golgi vesicle and mitochondria; and biomolecules like nucleic acids and proteins are transferred through these TnTs. These TnTs are long cytoplasmic extensions made up of actin that function as intercellular bridge and connect a wide verity of cell types. Malignant cells form TnTs with either another malignant cells or cells of the surrounding tumor matrix. These TnTs help in the process of initiation of tumor formation, its organization and propagation. The current review focuses on the role of TnTs mediated cell – cell signaling in cancer micro-environment. Drugs that inhibit TnT-formation such as metformin and everolimus can be targeted towards TnTs in the management of cancer growth, proliferation, tumor invasion and metastasis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

CALCULATIONS FOR A MERCURY JET TARGET IN A SOLENOID MAGNET CAPTURE SYSTEM

International Nuclear Information System (INIS)

GALLARDO, J.; KAHN, S.; PALMER, R.B.; THIEBERGER, P.; WEGGEL, R.J.; MCDONALD, K.

2001-01-01

A mercury jet is being considered as the production target for a muon storage ring facility to produce an intense neutrino beam. A 20 T solenoid magnet that captures pions for muon production surrounds the mercury target. As the liquid metal jet enters or exits the field eddy currents are induced. We calculate the effects that a liquid metal jet experiences in entering and exiting the magnetic field for the magnetic configuration considered in the Neutrino Factory Feasibility Study II

Flow evaluation of the leaching hazardous materials from spent nickel-cadmium batteries discarded in different water surroundings.

Science.gov (United States)

Guo, Xingmei; Song, Yan; Nan, Junmin

2018-02-01

The leaching characteristics of hazardous materials from Ni-Cd batteries immersed in four typical water samples, i.e., water with NaCl, river water, tap water, and deionized water, were investigated to evaluate the potential environmental harm of spent Ni-Cd batteries in the water surroundings. It is shown that four water surroundings all could leach hazardous materials from the Ni-Cd batteries. The water with NaCl concentration of 66.7 mg L -1 had the highest leaching ability, the hazardous materials were leached after only approximately 50 days (average time, with a standard deviation of 4.1), while less than 100 days were needed in the others. An electrochemical corrosion is considered to be the main leaching mechanism leading to battery breakage, while the dissolution-deposition process and the powder route result in the leakage and transference of nickel and cadmium materials from the electrodes. The anions, i.e., SO 4 2- and Cl - , and dissolved oxygen in water were demonstrated to be the vital factors that influence the leaching processes. Thus, it is proposed that spent Ni-Cd batteries must be treated properly to avoid potential danger to the environment.

Water pollution and cyanobacteria's variation of rivers surrounding southern Taihu Lake, China.

Science.gov (United States)

Sun, Mingyang; Huang, Linglin; Tan, Lisha; Yang, Zhe; Baig, Shams Ali; Sheng, Tiantian; Zhu, Hong; Xu, Xinhua

2013-05-01

The water quality and cyanobacterial variation of rivers surrounding southern Taihu Lake, China were purposively monitored from 2008 to 2010. Trophic level index (TLI) was used to evaluate the trophic levels of southern Taihu Lake. Results showed a considerable decline in the monitored data compared with 2007, and the data showed downward trends year after year. The TLI decreased from 55.6 to 51.3, which implied that southern Taihu Lake was mildly eutrophic. The water quality and cyanobacterial variation indicated a positive response to the adopted control measures in the southern Taihu Lake basin, but the intra- and inter-annual variability was still quite varied. High concentrations of nitrogen and phosphorus typically lead to algae outbreaks, however, the cyanobacteria growth may result in a decline of the concentration of nitrogen and phosphorus. Temperature and other weather conditions are also important factors for algae outbreaks; the risk of blue-green algal blooms still persists.

Motor training reduces surround inhibition in the motor cortex.

Science.gov (United States)

Akkad, Haya; Di Stasio, Flavio; Tibold, Robert; Kassavetis, Panagiotis; Rothwell, John C; Edwards, Mark J

2016-06-01

Surround inhibition (SI) is thought to facilitate focal contraction of a hand muscle by keeping nearby muscles silent. Unexpectedly, SI is reduced in skilled pianists. We tested whether repeated practice of focal contraction in non-pianists could reduce SI. Motor-evoked potentials were elicited by transcranial magnetic stimulation in the relaxed abductor digiti minimi randomly at the onset and 5s after offset of a 2s focal contraction (10% maximum) of the first dorsal interosseous (FDI). Over 5 blocks of 40 trials participants obtained points for increasing contraction speed and stability in FDI. In a final block, the interval between contractions was varied randomly to increase attention to the task. Over the first 5 blocks, SI declined as performance (points scored) improved. In the final "attention" block SI increased towards baseline without affecting performance. Although SI may be useful during the early stages of learning, skilled focal finger movement does not require SI to prevent activity in non-involved muscles. This could be due to better targeting of the excitatory command to move. Results from the final block suggest that increased attention can re-engage SI when task parameters change. SI is not necessary for successful focal contraction, but may contribute during learning and during attention to task. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

HAMS: High-Affinity Mass Spectrometry Screening. A High-Throughput Screening Method for Identifying the Tightest-Binding Lead Compounds for Target Proteins with No False Positive Identifications.

Science.gov (United States)

Imaduwage, Kasun P; Go, Eden P; Zhu, Zhikai; Desaire, Heather

2016-11-01

A major challenge in drug discovery is the identification of high affinity lead compounds that bind a particular target protein; these leads are typically identified by high throughput screens. Mass spectrometry has become a detection method of choice in drug screening assays because the target and the ligand need not be modified. Label-free assays are advantageous because they can be developed more rapidly than assays requiring labels, and they eliminate the risk of the label interfering with the binding event. However, in commonly used MS-based screening methods, detection of false positives is a major challenge. Here, we describe a detection strategy designed to eliminate false positives. In this approach, the protein and the ligands are incubated together, and the non-binders are separated for detection. Hits (protein binders) are not detectable by MS after incubation with the protein, but readily identifiable by MS when the target protein is not present in the incubation media. The assay was demonstrated using three different proteins and hundreds of non-inhibitors; no false positive hits were identified in any experiment. The assay can be tuned to select for ligands of a particular binding affinity by varying the quantity of protein used and the immobilization method. As examples, the method selectively detected inhibitors that have K i values of 0.2 μM, 50 pM, and 700 pM. These findings demonstrate that the approach described here compares favorably with traditional MS-based screening methods. Graphical Abstract ᅟ.

Surface Laser Scanning Measurements for the n_TOF spallation target

CERN Document Server

Vlachoudis, V; Cennini, P; Lebbos, E; Lettry, J

2010-01-01

The n_TOF spallation target is made of pure lead immersed into cooling water. The target was operating normally from 2001 until august 2004, when an increased transfer of radioactive products from the spallation target to the cooling circuit has been observed. The target was considered damaged by the safety commission (SC/RP), and an investigation campaign started to verify the actual status of the target. According to FLUKA and Ansys calculations the target was working in the elastoplastic regime of the lead material, therefore a deformation might be expected. The present paper describes a laser photographic method and the results of a possible such deformation. The target had a surface activity of the order of 20 mSv/h, therefore we were forced to perform the measurement from distance. The used method, is based on a linelaser and a high resolution digital camera for retrieving the 3D position of the surface of the lead target. Similar methods are used in the film industry and animation studios for scanning ...

El enfoque de la mezcla surround en la música

OpenAIRE

Castro Gómez, Albert

2010-01-01

El método estandarizado de escuchar música es el conocido sistema estéreo. Únicamente con dos altavoces o dos auriculares se escucha cualquier tipo de sonido de la manera más cómoda, usándolo en la mayoría de reproductores, ordenadores, coches, etc… pero hay otras formas de escuchar música. Nuevas técnicas de sonido que amplían la respuesta auditiva. Este nuevo sonido se conoce como sonido envolvente, internacionalmente llamado sonido surround. El sonido surround trabaja con más canales audit...

Two (or three) is one too many : testing the flexibility of contextual cueing with multiple target locations

OpenAIRE

Zellin, Martina; Conci, Markus; von Mühlenen, Adrian; Müller, Hermann J.

2011-01-01

Visual search for a target object is facilitated when the object is repeatedly presented within an invariant context of surrounding items ("contextual cueing"; Chun & Jiang, Cognitive Psychology, 36, 28-71, 1998). The present study investigated whether such invariant contexts can cue more than one target location. In a series of three experiments, we showed that contextual cueing is significantly reduced when invariant contexts are paired with two rather than one possible target location, whe...

GABA concentration is reduced in visual cortex in schizophrenia and correlates with orientation-specific surround suppression.

Science.gov (United States)

Yoon, Jong H; Maddock, Richard J; Rokem, Ariel; Silver, Michael A; Minzenberg, Michael J; Ragland, J Daniel; Carter, Cameron S

2010-03-10

The neural mechanisms underlying cognitive deficits in schizophrenia remain essentially unknown. The GABA hypothesis proposes that reduced neuronal GABA concentration and neurotransmission results in cognitive impairments in schizophrenia. However, few in vivo studies have directly examined this hypothesis. We used magnetic resonance spectroscopy (MRS) at high field to measure visual cortical GABA levels in 13 subjects with schizophrenia and 13 demographically matched healthy control subjects. We found that the schizophrenia group had an approximately 10% reduction in GABA concentration. We further tested the GABA hypothesis by examining the relationship between visual cortical GABA levels and orientation-specific surround suppression (OSSS), a behavioral measure of visual inhibition thought to be dependent on GABAergic synaptic transmission. Previous work has shown that subjects with schizophrenia exhibit reduced OSSS of contrast discrimination (Yoon et al., 2009). For subjects with both MRS and OSSS data (n = 16), we found a highly significant positive correlation (r = 0.76) between these variables. GABA concentration was not correlated with overall contrast discrimination performance for stimuli without a surround (r = -0.10). These results suggest that a neocortical GABA deficit in subjects with schizophrenia leads to impaired cortical inhibition and that GABAergic synaptic transmission in visual cortex plays a critical role in OSSS.

Characterization studies of prototype ISOL targets for the RIA

International Nuclear Information System (INIS)

Greene, John P.; Burtseva, Tatiana; Neubauer, Janelle; Nolen, Jerry A.; Villari, Antonio C.C.; Gomes, Itacil C.

2005-01-01

Targets employing refractory compounds are being developed for the rare isotope accelerator (RIA) facility to produce ion species far from stability. With the 100 kW beams proposed for the production targets, dissipation of heat becomes a challenging issue. In our two-step target design, neutrons are generated in a refractory primary target, inducing fission in the surrounding uranium carbide. The interplay of density, grain size, thermal conductivity and diffusion properties of the UC 2 needs to be well understood before fabrication. Thin samples of uranium carbide were prepared for thermal conductivity measurements using an electron beam to heat the sample and an optical pyrometer to observe the thermal radiation. Release efficiencies and independent thermal analysis on these samples are being undertaken at Oak Ridge National Laboratory (ORNL). An alternate target concept for RIA, the tilted slab approach promises to be simple with fast ion release and capable of withstanding high beam intensities while providing considerable yields via spallation. A proposed small business innovative research (SBIR) project will design a prototype tilted target, exploring the materials needed for fabrication and testing at an irradiation facility to address issues of heat transfer and stresses within the target

Characterization studies of prototype ISOL targets for the RIA

Science.gov (United States)

Greene, John P.; Burtseva, Tatiana; Neubauer, Janelle; Nolen, Jerry A.; Villari, Antonio C. C.; Gomes, Itacil C.

2005-12-01

Targets employing refractory compounds are being developed for the rare isotope accelerator (RIA) facility to produce ion species far from stability. With the 100 kW beams proposed for the production targets, dissipation of heat becomes a challenging issue. In our two-step target design, neutrons are generated in a refractory primary target, inducing fission in the surrounding uranium carbide. The interplay of density, grain size, thermal conductivity and diffusion properties of the UC2 needs to be well understood before fabrication. Thin samples of uranium carbide were prepared for thermal conductivity measurements using an electron beam to heat the sample and an optical pyrometer to observe the thermal radiation. Release efficiencies and independent thermal analysis on these samples are being undertaken at Oak Ridge National Laboratory (ORNL). An alternate target concept for RIA, the tilted slab approach promises to be simple with fast ion release and capable of withstanding high beam intensities while providing considerable yields via spallation. A proposed small business innovative research (SBIR) project will design a prototype tilted target, exploring the materials needed for fabrication and testing at an irradiation facility to address issues of heat transfer and stresses within the target.

Targeted Therapy in Nonmelanoma Skin Cancers

International Nuclear Information System (INIS)

Spallone, Giulia; Botti, Elisabetta; Costanzo, Antonio

2011-01-01

Nonmelanoma skin cancer (NMSC) is the most prevalent cancer in light-skinned populations, and includes mainly Basal Cell Carcinomas (BCC), representing around 75% of NMSC and Squamous Cell Carcinomas (SCC). The incidence of these tumors is continuously growing. It was found that the overall number of procedures for NMSC in US rose by 76%, from 1,158,298 in 1992 to 2,048,517 in 2006. Although mortality from NMSC tends to be very low, clearly the morbidity related to these skin cancers is very high. Treatment options for NMSC include both surgical and nonsurgical interventions. Surgery was considered the gold standard therapy, however, advancements in the knowledge of pathogenic mechanisms of NMSCs led to the identification of key targets for drug intervention and to the consequent development of several targeted therapies. These represent the future in treatment of these common forms of cancer ensuring a high cure rate, preservation of the maximal amount of normal surrounding tissue and optimal cosmetic outcome. Here, we will review recent advancements in NMSC targeted therapies focusing on BCC and SCC

Targeted Therapy in Nonmelanoma Skin Cancers

Directory of Open Access Journals (Sweden)

Giulia Spallone

2011-05-01

Full Text Available Nonmelanoma skin cancer (NMSC is the most prevalent cancer in light-skinned populations, and includes mainly Basal Cell Carcinomas (BCC, representing around 75% of NMSC and Squamous Cell Carcinomas (SCC. The incidence of these tumors is continuously growing. It was found that the overall number of procedures for NMSC in US rose by 76%, from 1,158,298 in 1992 to 2,048,517 in 2006. Although mortality from NMSC tends to be very low, clearly the morbidity related to these skin cancers is very high. Treatment options for NMSC include both surgical and nonsurgical interventions. Surgery was considered the gold standard therapy, however, advancements in the knowledge of pathogenic mechanisms of NMSCs led to the identification of key targets for drug intervention and to the consequent development of several targeted therapies. These represent the future in treatment of these common forms of cancer ensuring a high cure rate, preservation of the maximal amount of normal surrounding tissue and optimal cosmetic outcome. Here, we will review recent advancements in NMSC targeted therapies focusing on BCC and SCC.

Study on the Optimal Equivalent Radius in Calculating the Heat Dissipation of Surrounding Rock

Directory of Open Access Journals (Sweden)

H. T. Song

2015-11-01

Full Text Available The heat dissipation of surrounding rock of a non-circular roadway is computed using an equivalent circular roadway approach under three circumstances when the area, perimeter, or hydraulic diameter of the circular roadway is equal to the non-circular roadway to obtain the optimal equivalent radius. The differential equations of heat conduction for unstable surrounding rock are established in cylindrical and rectangular coordinate systems using dimensionless analysis method. The calculation formulas of heat dissipation capacity and heat transfer resistance are derived from differential equations. Based on the method of equivalent radius, the similarities and differences between non-circular and circular roadways in calculating the heat dissipation of surrounding rock are discussed. Using the finite volume method, the calculation models for non-circular and circular roadways in the heat dissipation of surrounding rock are also established, among the non-circular roadways including three circumstances, namely, trapezoid, rectangle, and arch. The relation errors of heat dissipation of the surrounding rock of the three equivalent circular roadway methods are investigated for the three non-circular roadways. Results show that the calculation approach with equal perimeters is the best for the heat dissipation of surrounding rock of non-circular roadways.

Total fragmentation cross section of 158A GeV lead projectiles in Cu target

International Nuclear Information System (INIS)

Mukhtar Ahmed Rana; Shahid Manzoor

2008-01-01

Total fragmentation cross section for the reaction 158A Pb ions + Cu target is measured using the most sensitive track detector CR-39. Measured values are compared with calculations. Exposures of target-detector stack with 158A Pb projectiles are made at CERN-SPS beam facility. Results of calibration of CR-39 detector in a charge region (63≤Z≤83) are also reported, which can be used for high energy particle identification using CR-39 and in determination of partial charge changing cross sections. The charge resolution σ Z achieved by this technique is about 0.2e. A systematic dependence of total fragmentation cross section on target properties is revealed and the corresponding results are presented. (authors)

Ultrastructural relationship of the phagophore with surrounding organelles.

Science.gov (United States)

Biazik, Joanna; Ylä-Anttila, Päivi; Vihinen, Helena; Jokitalo, Eija; Eskelinen, Eeva-Liisa

2015-01-01

Phagophore nucleates from a subdomain of the endoplasmic reticulum (ER) termed the omegasome and also makes contact with other organelles such as mitochondria, Golgi complex, plasma membrane and recycling endosomes during its formation. We have used serial block face scanning electron microscopy (SB-EM) and electron tomography (ET) to image phagophore biogenesis in 3 dimensions and to determine the relationship between the phagophore and surrounding organelles at high resolution. ET was performed to confirm whether membrane contact sites (MCSs) are evident between the phagophore and those surrounding organelles. In addition to the known contacts with the ER, we identified MCSs between the phagophore and membranes from putative ER exit sites, late endosomes or lysosomes, the Golgi complex and mitochondria. We also show that one phagophore can have simultaneous MCSs with more than one organelle. Future membrane flux experiments are needed to determine whether membrane contacts also signify lipid translocation.

Corrector/quadrupole/sextupole power leads for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory

International Nuclear Information System (INIS)

Shutt, R.; Hornik, K.; Rehak, M.

1993-01-01

In RHIC (Relativistic Heavy Ion Collider), there are 492 CQS (Corrector/Quadrupole/Sextupole) assemblies which require leads to carry the current from the power supply to the magnet. The lead assemblies will contain these leads along with instrumentation voltage taps and current carrying wires that are used only for magnet warm-up. These lead assemblies are analyzed for two cooling schemes: (1) gas flow through the lead tube and (2) heat sinking the lead tube along a 40--70 K heat shield (without gas flow). The analysis was extended to include the modeling of the cold and warm ends and effects of superinsulation shielding the lead assembly against radiation (including heat conduction due to residual gas pressure in the surrounding vacuum). Extensive parametric studies of heat exchange areas, specific copper properties, length of the lead, etc. are also included in the analysis

Continuous activation of Nrf2 and its target antioxidant enzymes leads to arsenite-induced malignant transformation of human bronchial epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Yang, Xu [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Wang, Dapeng [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Department of Toxicology, School of Public Health, Guizhou Medical University, Guiyang, Guizhou (China); Ma, Yuan; Xu, Xiguo; Zhu, Zhen; Wang, Xiaojuan; Deng, Hanyi; Li, Chunchun; Chen, Min; Tong, Jian [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Yamanaka, Kenzo [Laboratory of Environmental Toxicology and Carcinogenesis, School of Pharmacy, Nihon University, Chiba (Japan); An, Yan, E-mail: dranyan@126.com [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China)

2015-12-01

Long-term exposure to arsenite leads to human lung cancer, but the underlying mechanisms of carcinogenesis remain obscure. The transcription factor of nuclear factor-erythroid-2 p45-related factor (Nrf2)-mediated antioxidant response represents a critical cellular defense mechanism and protection against various diseases. Paradoxically, emerging data suggest that the constitutive activation of Nrf2 is associated with cancer development, progression and chemotherapy resistance. However, the role of Nrf2 in the occurrence of cancer induced by long-term arsenite exposure remains to be fully understood. By establishing transformed human bronchial epithelial (HBE) cells via chronic low-dose arsenite treatment, we showed that, in acquiring this malignant phenotype, continuous low level of ROS and sustained enhancement of Nrf2 and its target antioxidant enzyme levels were observed in the later-stage of arsenite-induced cell transformation. The downregulation of Keap1 level may be responsible for the over-activation of Nrf2 and its target enzymes. To validate these observations, Nrf2 was knocked down in arsenite-transformed HBE cells by SiRNA transfection, and the levels of Nrf2 and its target antioxidant enzymes, ROS, cell proliferation, migration, and colony formation were determined following these treatments. Results showed that blocked Nrf2 expression significantly reduced Nrf2 and its target antioxidant enzyme levels, restored ROS levels, and eventually suppressed cell proliferation, migration, and colony formation of the transformed cells. In summary, the results of the study strongly suggested that the continuous activation of Nrf2 and its target antioxidant enzymes led to the over-depletion of intracellular ROS levels, which contributed to arsenite-induced HBE cell transformation. - Highlights: • Low level, long term arsenite exposure induces malignant transformation in vitro. • Long term arsenite exposure reduces ROS and MDA levels. • Long term arsenite

Continuous activation of Nrf2 and its target antioxidant enzymes leads to arsenite-induced malignant transformation of human bronchial epithelial cells

International Nuclear Information System (INIS)

Yang, Xu; Wang, Dapeng; Ma, Yuan; Xu, Xiguo; Zhu, Zhen; Wang, Xiaojuan; Deng, Hanyi; Li, Chunchun; Chen, Min; Tong, Jian; Yamanaka, Kenzo; An, Yan

2015-01-01

Long-term exposure to arsenite leads to human lung cancer, but the underlying mechanisms of carcinogenesis remain obscure. The transcription factor of nuclear factor-erythroid-2 p45-related factor (Nrf2)-mediated antioxidant response represents a critical cellular defense mechanism and protection against various diseases. Paradoxically, emerging data suggest that the constitutive activation of Nrf2 is associated with cancer development, progression and chemotherapy resistance. However, the role of Nrf2 in the occurrence of cancer induced by long-term arsenite exposure remains to be fully understood. By establishing transformed human bronchial epithelial (HBE) cells via chronic low-dose arsenite treatment, we showed that, in acquiring this malignant phenotype, continuous low level of ROS and sustained enhancement of Nrf2 and its target antioxidant enzyme levels were observed in the later-stage of arsenite-induced cell transformation. The downregulation of Keap1 level may be responsible for the over-activation of Nrf2 and its target enzymes. To validate these observations, Nrf2 was knocked down in arsenite-transformed HBE cells by SiRNA transfection, and the levels of Nrf2 and its target antioxidant enzymes, ROS, cell proliferation, migration, and colony formation were determined following these treatments. Results showed that blocked Nrf2 expression significantly reduced Nrf2 and its target antioxidant enzyme levels, restored ROS levels, and eventually suppressed cell proliferation, migration, and colony formation of the transformed cells. In summary, the results of the study strongly suggested that the continuous activation of Nrf2 and its target antioxidant enzymes led to the over-depletion of intracellular ROS levels, which contributed to arsenite-induced HBE cell transformation. - Highlights: • Low level, long term arsenite exposure induces malignant transformation in vitro. • Long term arsenite exposure reduces ROS and MDA levels. • Long term arsenite

An experimental investigation of transient heat transfer in surrounding rock mass of high geothermal roadway

Directory of Open Access Journals (Sweden)

Zhang Yuan

2016-01-01

Full Text Available A self-designed experimental installation for transient heat transfer in the modelling surrounding rock mass of high geothermal roadways was elaborated in this paper. By utilizing the new installation, the temperature variation rules in surrounding rock mass of the high geothermal roadway during mechanical ventilation were studied. The results show that the roadway wall temperature decreases dramatically at the early stage of ventilation, and the temperature at every position of the surrounding rock mass is decreasing constantly with time passing by. From roadway wall to deep area, the temperature gradually increases until reaching original rock temperature. The relationship between dimensionless temperature and dimensionless radius demonstrates approximately exponential function. Meanwhile, the temperature disturbance range in the simulated surrounding rock mass extends gradually from the roadway wall to deep area in the surrounding rock mass. Besides, as the air velocity increases, heat loss in the surrounding rock mass rises and the ratio of temperature reduction becomes larger, the speed of disturbance range expansion also gets faster.

Linking disadvantaged housing areas to the surrounding city

DEFF Research Database (Denmark)

Stender, Marie

Several disadvantaged social housing areas in Denmark are currently undergo-ing thorough physical refurbishments, aiming to integrate them better with the surrounding city. The ambition is to attract new users and residents by opening up the borders of the area and establish attractive, new...

Total Fragmentation Cross Section of 158A GeV Lead Projectiles in Cu Target

International Nuclear Information System (INIS)

Rana, Mukhtar Ahmed

2008-01-01

Total fragmentation cross section for the reaction 158 A Pb ions + Cu target is measured using the most sensitive track detector CR-39. Measured values are compared with calculations. Exposures of target-detector stack with 158A Pb projectiles are made at CERN-SPS beam facility. Results of calibration of CR-39 detector in a charge region (63 ≤ Z ≤ 83) are also reported, which can be used for high energy particle identification using CR-39 and in determination of partial charge changing cross sections. The charge resolution σ z achieved by this technique is about 0.2e. A systematic dependence of total fragmentation cross section on target properties is revealed and the corresponding results are presented. (nuclear physics)

On non-linear magnetic-charged black hole surrounded by quintessence

Science.gov (United States)

Nam, Cao H.

2018-06-01

We derive a non-linear magnetic-charged black hole surrounded by quintessence, which behaves asymptotically like the Schwarzschild black hole surrounded by quintessence but at the short distances like the dS geometry. The horizon properties of this black hole are investigated in detail. The thermodynamics of the black hole is studied in the local and global views. Finally, by calculating the heat capacity and the free energy, we point to that the black hole may undergo a thermal phase transition, between a larger unstable black hole and a smaller stable black hole, at a critical temperature.

Crust Structure Data of Seas Surrounding Turkey

International Nuclear Information System (INIS)

Maden, N.; Gelisli, K.

2007-01-01

Black Sea, Aegean, Mediterranean and Marmara Sea, which surround the Turkey, have not been examined with respect to the Geological, Geophysical and other natural sciences sufficiently. In fact, it is not attach importance the Turkish seas adequately and abandoned with respect to the scientific researches. The most important reason of this situation is the lack of the education of the Marine Sciences in the Turkish Universities. In this study, it is tried to construct a crustal structure data base of the surrounding seas of the Turkey by collecting crustal structure data sets done by different authors in different times so far. The data acquired in the base are collected from different data base sources by dragging. The Moho depth in the eastern and western basin of the Black sea is 22 km and 19 km, respectively. In the Marmara Sea the Moho depth is 24 km. The moho value in the southern Aegean is 20 km, in the northern Aegean the moho depth is 30 km. on the other hand, the moho depth value in the eastern and western basin of the Mediterranean Sea are 15-20 km and 25-30 km, respectively

XAFS studies of nickel-doped lead telluride

International Nuclear Information System (INIS)

Radisavljevic, Ivana; Novakovic, Nikola; Ivanovic, Nenad; Romcevic, Nebojsa; Manasijevic, Miodrag; Mahnke, Heinz-Eberhard

2009-01-01

The problem of impurities and defect states in lead telluride-based semiconductors is of crucial importance for their practical applications. X-ray absorption fine structure (XAFS) techniques are capable to address some of the key issues regarding impurities position, their valent state, as well as the local structural changes of the host lattice in the immediate surrounding of the impurity atoms. In this paper we present the results of the Ni K-absorption edge XAFS studies of Ni-doped PbTe at different temperatures. Analysis of near edge and extended XAFS regions of the measured spectra provided information about exact local environment and lattice ordering around Ni atoms.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

A beam of 1 GeV proton coming from Dubna Nuclotron colliding with a lead target surrounded by 6 cm paraffin produces spallation neutrons. A Th-foil was kept on lead target (neutron spallation source) in a direct stream of neutrons for activation and other samples of 197Au, 209Bi, 59Co, 115In and 181Ta were irradiated by ...

Enhancing area surrounding breast carcinoma on MR mammography: comparison with pathological examination

International Nuclear Information System (INIS)

Goethem, M. van; Verslegers, I.; Biltjes, I.; Schepper, A. de; Schelfout, K.; Colpaert, C.; Kersschot, E.; Tjalma, W.A.; Weyler, J.

2004-01-01

The enhancing area surrounding breast carcinoma on MR mammography is correlated with findings from pathological examination. We studied 194 patients with breast cancer who underwent preoperative MR mammography. Of all malignant lesions presenting with an enhancing surrounding area on MR mammography, morphologic features including long spicules, a ductal pattern, diffuse enhancement or nodules were evaluated and compared with histopathological examination. A double breast coil was used; we performed a 3D FLASH sequence with contiguous coronal slices of 2 mm, before and after injection of 0.2 mmol/kg GD-DTPA, and subtraction images were obtained. In total, 297 malignant lesions were detected at MR mammography and 101 of them had one or more types of enhancing surrounding area. In 49 of the 53 cancers with long spicules and in 49 of the 55 cancers with surrounding ductal pattern of enhancement, pathological examination showed in situ and/or invasive carcinoma. Multiple nodules adjacent to the carcinoma were seen in 20 patients and corresponded with six cases of invasive and ten cases of ductal in situ carcinoma. A diffuse enhancing area next to a mass was seen in ten patients and consisted of carcinoma in all cases: seven in situ and three invasive carcinomas. Enhancing areas including long spicules, a ductal pattern, noduli, or diffuse enhancement surrounding a carcinoma corresponded with in situ or invasive extension of the carcinoma in 92.5, 89, 80 and 100% of cases, respectively. (orig.)

Analytical and numerical description of the PELE fragmentation upon impact with thin target plates

NARCIS (Netherlands)

Verreault, J.

2015-01-01

The PELE ammunition is characterized by a low-density filling material surrounded by a high-density brittle jacket material. An analytical model describing the fragmentation of this ammunition behind a target plate is presented. This model assumes uniaxial strain in the filling and uses the

SU-E-T-531: Large--Scale DVH Quality Study: Correlated Aims Lead Relaxations

Energy Technology Data Exchange (ETDEWEB)

Nohadani, O; Roy, A [Northwestern University, Evanston, IL (United States); Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

2015-06-15

Purpose: Intensity modulated radiation therapy plans are designed to optimally target a tumor while sparing surrounding tissue. Desired dose distributions are iteratively approached via inverse planning. This leads to tradeoffs between clinical objectives for the planning target volume (PTV), organs at risk, and normal tissues. Dose volume histogram (DVHs) related aims are followed that are either institutional or internationally recommended. We analyze common goals and identify potential reasons that often lead to tradeoffs. Methods: 524 IMRT plans for various tumor sites were analyzed based on the main institutional DVH goal for PTV (D95) and the recommendations by ICRU-83 (D2, D50, and D98). Robust statistical tools are developed and applied to ensure that the results are immune to data uncertainties. The probability of violation was measured for each of the DVH goals based on the frequency of not meeting recommended doses. Conditional probabilities for satisfying and/or violating DVH aims were computed to test the hypothesized pair-wise relations between DVH aims. For example, for plans that satisfied D50, the probability of violating D98 was computed via P(D98 < 95% | 98% ≤ D50 ≤ 102%). The equality constraint D50 = 100% was relaxed to encompass the range [98,102]%. Results: A large majority of cases (88%) satisfied the institutional goal for PTV of D95 ≤ 95%. Similar consensus existed for D98. 51% of cases satisfied D2 ≥ 107%. However, only 18% of cases satisfied D50. The conditional probability showed correlations amongst the studied DVH goals. In fact, a negative correlation was revealed between D50 and D95 (and D98), suggesting that these competing goals cannot be satisfied concurrently. Conclusion: The majority of plans followed the institutional guidelines. The reason for their deviation from international recommendations seems to be that the latter goals are competing and cannot be satisfied concurrently in clinical practice.

Target volume geometric change and/or deviation from the cranium during fractionated stereotactic radiotherapy for brain metastases: potential pitfalls in image guidance based on bony anatomy alignment.

Science.gov (United States)

Ohtakara, Kazuhiro; Hoshi, Hiroaki

2014-12-01

This study sought to evaluate the potential geometrical change and/or displacement of the target relative to the cranium during fractionated stereotactic radiotherapy (FSRT) for treating newly developed brain metastases. For 16 patients with 21 lesions treated with image-guided frameless FSRT in 5 or 10 fractions using a 6-degree-of-freedom image guidance system-integrated platform, the unenhanced computed tomography or T2-weighted magnetic resonance images acquired until the completion of FSRT were fused to the planning image datasets for comparison. Significant change was defined as ≥3-mm change in the tumour diameter or displacement of the tumour centroid. FSRT was started 1 day after planning image acquisition. Tumour shrinkage, deviation and both were observed in 2, 1 and 1 of the 21 lesions, respectively, over a period of 7-13 days. Tumour shrinkage or deviation resulted in an increase or decrease in the marginal dose to the tumour, respectively, and a substantial increase in the irradiated volume for the surrounding tissue irrespective of the pattern of alteration. No obvious differences in the clinical and treatment characteristics were noted among the populations with or without significant changes in tumour volume or position. Target deformity and/or deviation can unexpectedly occur even during relatively short-course FSRT, inevitably leading to a gradual discrepancy between the planned and actually delivered doses to the tumour and surrounding tissue. To appropriately weigh the treatment outcome against the planned dose distribution, target deformity and/or deviation should also be considered in addition to the immobilisation accuracy, as image guidance with bony anatomy alignment does not necessarily guarantee accurate target localisation until completion of FSRT. © 2014 The Royal Australian and New Zealand College of Radiologists.

Opportunity's Surroundings on Sol 1687

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a cylindrical projection with geometric seam correction.

Opportunity's Surroundings on Sol 1798

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

Analysis of the AGS experiment on a mercury target with a moderator and a lead reflector bombarded by GeV energy protons

International Nuclear Information System (INIS)

Maekawa, Fujio; Meigo, Shin-ichiro; Kasugai, Yoshimi; Takada, Hiroshi; Ikeda, Yujiro; Ino, Takashi; Sato, Setsuo

2001-01-01

The AGS experiment on a mercury target with a moderator and a lead reflector bombarded by GeV energy protons was analyzed to investigate prediction capability of Monte Carlo simulation codes used in neutronic designs of spallation neutron sources. The NMTC/JAM code was used for nucleon meson transport calculations above 20 MeV while the MCNP-4A code with the JENDL cross section library was used for neutron transport below 20 MeV. The MCNPX code with the LA-150 library was also used for a reference. The calculations were compared with the experimental data obtained with 1.94, 12 and 24 GeV proton beams: (1) neutron flux distributions along the mercury target and (2) spectral fluxes of thermal neutrons extracted from a light water moderator. As a result, it was found that all the calculations predicted these experimental results with accuracies better than ±50% in absolute values. Accordingly, it was concluded that these calculation codes were adequate for neutronics designs of spallation neutron sources. (author)

Setting realistic recovery targets for two interacting endangered species, sea otter and northern abalone.

Science.gov (United States)

Chadès, Iadine; Curtis, Janelle M R; Martin, Tara G

2012-12-01

Failure to account for interactions between endangered species may lead to unexpected population dynamics, inefficient management strategies, waste of scarce resources, and, at worst, increased extinction risk. The importance of species interactions is undisputed, yet recovery targets generally do not account for such interactions. This shortcoming is a consequence of species-centered legislation, but also of uncertainty surrounding the dynamics of species interactions and the complexity of modeling such interactions. The northern sea otter (Enhydra lutris kenyoni) and one of its preferred prey, northern abalone (Haliotis kamtschatkana), are endangered species for which recovery strategies have been developed without consideration of their strong predator-prey interactions. Using simulation-based optimization procedures from artificial intelligence, namely reinforcement learning and stochastic dynamic programming, we combined sea otter and northern abalone population models with functional-response models and examined how different management actions affect population dynamics and the likelihood of achieving recovery targets for each species through time. Recovery targets for these interacting species were difficult to achieve simultaneously in the absence of management. Although sea otters were predicted to recover, achieving abalone recovery targets failed even when threats to abalone such as predation and poaching were reduced. A management strategy entailing a 50% reduction in the poaching of northern abalone was a minimum requirement to reach short-term recovery goals for northern abalone when sea otters were present. Removing sea otters had a marginally positive effect on the abalone population but only when we assumed a functional response with strong predation pressure. Our optimization method could be applied more generally to any interacting threatened or invasive species for which there are multiple conservation objectives. © 2012 Society for

Electromagnetic three-dimensional reconstruction of targets from free space experimental data

International Nuclear Information System (INIS)

Geffrin, J.-M.; Chaumet, P. C.; Eyraud, C.; Belkebir, K.; Sabouroux, P.

2008-01-01

This paper deals with the problem of reconstructing the relative permittivity of three-dimensional targets using experimental scattered fields. The fields concerned were measured in an anechoic chamber on the surface of a sphere surrounding the target. The inverse scattering problem is reformulated as an optimization problem that is iteratively solved thanks to a conjugate gradient method and by using the coupled dipoles method as a forward problem solver. The measurement technique and the inversion procedure are briefly described with the inversion results. This work demonstrates the reliability of the experiments and the efficiency of the proposed inverse scattering scheme

Current practices in generation of small molecule new leads.

Science.gov (United States)

Goodnow, R A

2001-01-01

The current drug discovery processes in many pharmaceutical companies require large and growing collections of high quality lead structures for use in high throughput screening assays. Collections of small molecules with diverse structures and "drug-like" properties have, in the past, been acquired by several means: by archive of previous internal lead optimization efforts, by purchase from compound vendors, and by union of separate collections following company mergers. More recently, many drug discovery companies have established dedicated efforts to effect synthesis by internal and/or outsourcing efforts of targeted compound libraries for new lead generation. Although high throughput/combinatorial chemistry is an important component in the process of new lead generation, the selection of library designs for synthesis and the subsequent design of library members has evolved to a new level of challenge and importance. The potential benefits of screening multiple small molecule compound library designs against multiple biological targets offers substantial opportunity to discover new lead structures. Subsequent optimization of such compounds is often accelerated because of the structure-activity relationship (SAR) information encoded in these lead generation libraries. Lead optimization is often facilitated due to the ready applicability of high-throughput chemistry (HTC) methods for follow-up synthesis. Some of the strategies, trends, and critical issues central to the success of lead generation processes are discussed below. Copyright 2002 Wiley-Liss, Inc.

Surrounding information consideration promotes cooperation in Prisoner’s dilemma game

International Nuclear Information System (INIS)

Shu, Gang; Du, Xia; Li, Ya

2016-01-01

Highlights: • A new method of strategy updating is proposed in the Prisoner’s dilemma game. • The stochastic players only consider their neighbor’s payoff and update strategy by classical Fermi rule. • The advanced player would consider not only the neighbor’s payoff but also the neighbors’ local surrounding information. • The simulation result illustrates that with the increase of advanced players in the network, the fraction of cooperation increases. - Abstract: Evolutionary game theory provides a useful, integrative framework for studying the evolution of cooperation. A new strategy updating method is proposed in our model. Due to people with diversified thinking, players are divided into two categories based on their different strategy updating method: ordinary players and advanced players. The former players only consider their neighbor’s payoff and updating strategy by classical Fermi rule, while the latter players take both the neighbors’ surrounding information and payoff into account. The results show that the neighbors surrounding information consideration contributes to the evolution of cooperation and finds the fraction of cooperation grows evidently with the increase of advanced players numbers. Our model may provide a pragmatic approach to the research of cooperation in social network.

Target and lithium-lens of the AA

CERN Multimedia

Photographic Service; CERN PhotoLab

1985-01-01

As an alternative to the "Magnetic Horn", a "Current Lens" was used to focus antiprotons emerging from the production target. Lithium was chosen as it is the lightest metal, for minimal scattering and losses. This first version had at its core a lithium rod, 34 mm in diameter and 115 mm long. It is surrounded by a pulse transformer, which induced currents up to 850 kA. Later, with LEAR as the only client, in a more modest version a 20 mm lithium rod was pulsed to 480 kA.

Glow phenomenon surrounding the vertical stabilizer and OMS pods

Science.gov (United States)

1994-01-01

This 35mm frame, photographed as the Space Shuttle Columbia was orbiting Earth during a 'night' pass, documents the glow phenomenon surrounding the vertical stabilizer and the Orbital Maneuvering System (OMS) pods of the spacecraft.

SU-E-T-278: Dose Conformity Index for the Target in a Multitarget Environment

Energy Technology Data Exchange (ETDEWEB)

Harikrishnaperumal, Sudahar [Apollo Speciality Hospital, Chennai, Tamil Nadu (India)

2015-06-15

Purpose: The existing conformity index formulations are failing when multiple targets present outside the target of interest with same or different dose prescriptions. In the present study a novel methodology is introduced to solve this issue. Methods: The conformity index used by Nakamura et al (Int J Radiat Oncol Biol Phys 2001; 51(5):1313–1319) is taken as the base for this methodology. In this proposal, the prescription isodose volume (PIV) which normally includes the normal tissue and other target regions is restricted as PIV in annular regions of different thickness around the target of interest. The graphical line plotted between the thickness of annular region and the corresponding conformity index, will increase in the beginning and will reach a flat region, then it will increase again. The second increase in the conformity index depends basically on the distance between the targets, dose prescriptions, and size of the targets. The conformity index in the flat region should be the conformity index of the target of interest. This methodology was validated on dual target environment on a skull phantom in Multiplan planning system (Accuray Inc. Sunnyvale, USA) Results: When the surrounding target’s (sphere) size is changed from 1.5cm to 6cm diameter, the conformity index of the target of interest (3cm diameter) changed from 1.09 to 1.25. When the distance between the targets changed from 7.5cm to 2.5cm, the conformity index changed from 1.10 to 1.17. Similarly, when the prescribed dose changed from 25Gy to 50Gy the conformity index changed from 1.09 to 1.42. These values were above 2.0 when Nakamura et al formula was used. Conclusion: The proposed conformity index methodology eliminates the influence of surrounding targets to a greater extend. However, the limitations of this method should be studied further. Application of this method in clinical situations is the future scope.

Traditional Indian customs surrounding birth A review | Chalmers ...

African Journals Online (AJOL)

Since 1960, only a few studies have been made of traditional custOIns surrounding birth in Indian culture. Very few of these have described customs followed by Indians in South Africa. A review of these publications is presented here. Customs described include religious, social and psychological aspects of behaviour in ...

Methods of thallium-201 preparation from proton irradiated thallium targets

International Nuclear Information System (INIS)

Kozlova, M.D.; Sevast'yanova, A.S.; Malinin, A.B.; Kurenkov, N.V.

1989-01-01

Two methods of thallium-201 preparation from Tl-targets irradiated by protons: oxidation-extraction (1) and extraction (2) - are developed. At first radioactive lead is separated from the target material - thallium macroquantities during ∼32 hours, then thallium-201 was separated from residual activity of lead radioisotopes and transformed it into the necessary chemical formula. The 1st and 2nd methods differ from each other by the 1st stage of target retreatment; only extraction was used to separate radioactive lead in the 2nd method. The target was solved in H 2 SO 4 . The 1st method permits to separate thallium-201 with chemical yield not less than 90 %, the 2nd one - higher than 95 %. Volumetric activity of thallium-201 prepared is more than 55 MBq/ml. 5 refs

Depleted uranium instead of lead in munitions: the lesser evil.

Science.gov (United States)

Jargin, Sergei V

2014-03-01

Uranium has many similarities to lead in its exposure mechanisms, metabolism and target organs. However, lead is more toxic, which is reflected in the threshold limit values. The main potential hazard associated with depleted uranium is inhalation of the aerosols created when a projectile hits an armoured target. A person can be exposed to lead in similar ways. Accidental dangerous exposures can result from contact with both substances. Encountering uranium fragments is of minor significance because of the low penetration depth of alpha particles emitted by uranium: they are unable to penetrate even the superficial keratin layer of human skin. An additional cancer risk attributable to the uranium exposure might be significant only in case of prolonged contact of the contaminant with susceptible tissues. Lead intoxication can be observed in the wounded, in workers manufacturing munitions etc; moreover, lead has been documented to have a negative impact on the intellectual function of children at very low blood concentrations. It is concluded on the basis of the literature overview that replacement of lead by depleted uranium in munitions would be environmentally beneficial or largely insignificant because both lead and uranium are present in the environment.

Depleted uranium instead of lead in munitions: the lesser evil

International Nuclear Information System (INIS)

Jargin, Sergei V

2014-01-01

Uranium has many similarities to lead in its exposure mechanisms, metabolism and target organs. However, lead is more toxic, which is reflected in the threshold limit values. The main potential hazard associated with depleted uranium is inhalation of the aerosols created when a projectile hits an armoured target. A person can be exposed to lead in similar ways. Accidental dangerous exposures can result from contact with both substances. Encountering uranium fragments is of minor significance because of the low penetration depth of alpha particles emitted by uranium: they are unable to penetrate even the superficial keratin layer of human skin. An additional cancer risk attributable to the uranium exposure might be significant only in case of prolonged contact of the contaminant with susceptible tissues. Lead intoxication can be observed in the wounded, in workers manufacturing munitions etc; moreover, lead has been documented to have a negative impact on the intellectual function of children at very low blood concentrations. It is concluded on the basis of the literature overview that replacement of lead by depleted uranium in munitions would be environmentally beneficial or largely insignificant because both lead and uranium are present in the environment. (opinion)

How A Black Hole Lights Up Its Surroundings

Science.gov (United States)

Kohler, Susanna

2017-10-01

How do the supermassive black holes that live at the centers of galaxies influence their environments? New observations of a distant active galaxy offer clues about this interaction.Signs of CoevolutionPlot demonstrating the m-sigma relation, the empirical correlation between the stellar velocity dispersion of a galactic bulge and the mass of the supermassive black hole at its center. [Msigma]We know that the centers of active galaxies host supermassive black holes with masses of millions to billions of suns. One mystery surrounding these beasts is that they are observed to evolve simultaneously with their host galaxies for instance, an empirical relationship is seen between the growth of a black hole and the growth of its host galaxys bulge. This suggests that there must be a feedback mechanism through which the evolution of a black hole is linked to that of its host galaxy.One proposed source of this coupling is the powerful jets emitted from the poles of these supermassive black holes. These jets are thought to be produced as some of the material accreting onto the black hole is flung out, confined by surrounding gas and magnetic fields. Because the jets of hot gas and radiation extend outward through the host galaxy, they provide a means for the black hole to influence the gas and dust of its surroundings.In our current model of a radio-loud active galactic nuclei,a region of hot, ionized gas the narrow-line region lies beyond the sphere of influence of the supermassive black hole. [C.M. Urry and P. Padovani]Clues in the Narrow-Line RegionThe region of gas thought to sit just outside of the black holes sphere of influence (at a distance of perhaps a thousand to a few thousand light-years) is known as the narrow line region so named because we observe narrow emission lines from this gas. Given its hot, ionized state, this gas must somehow be being pummeled with energy. In the canonical picture, radiation from the black hole heats the gas directly in a process

Thermal neutron pulsed parameters in non-hydrogenous systems. Experiment for lead grains

International Nuclear Information System (INIS)

Drozdowicz, K.; Gabanska, B.; Kosik, M.; Krynicka, E.; Woznicka, U.; Zaleski, T.

1997-01-01

In Czubek's method of measurement of the thermal neutron macroscopic absorption cross section a two-region geometry is applied where the investigated sample is surrounded by an external moderator. Both regions in the measurements made up till now were hydrogenous, which means the same type of the thermal neutron transport properties. In the paper a theoretical consideration to use non-hydrogenous materials as the samples is presented. Pulsed neutron measurements have been performed on homogeneous material in a geometry of the classic experiment with the variable geometric buckling. Two decay constants have been measured for different cylindrical samples of small lead grains (a lead shot). (author)

Neutron Production in Spallation Reactions of 0.9 and 1.5 GeV Protons on a Thick Lead Target. Comparison between Experimental Data and Monte-Carlo Simulations

CERN Document Server

Krasa, A; Bradnova, V; Caloun, P; Chultem, D; Henzl, V; Henzlová, D; Kalinnikov, V G; Krivopustov, M I; Krízek, F; Kugler, A; Majerle, M; Solnyshkin, A A; Stegailov, V I; Tsoupko-Sitnikov, V M; Tumendelger, T; Vasilev, S I; Wagner, V; Nuclear Physics Institute of Academy of Sciences of Czech Republic, Rez, Czech Republic

2005-01-01

This paper reports on two experiments performed at the Synchrophasotron/Nuclotron accelerator complex at JINR. Relativistic protons with energies 885 MeV and 1.5 GeV hit a massive cylindrical lead target. The spatial and energetic distributions of the neutron field produced by the spallation reactions were measured by the activation of Al, Au, Bi, Co, and Cu foils placed on the surface of the target and close to it. The yields of the radioactive nuclei produced by threshold reactions in these foils were determined by the analyses of their $\\gamma$ spectra. The comparison with Monte-Carlo based simulations was performed both with the LAHET+MCNP code and the MCNPX code.

Neutron production in spallation reactions of 0.9 and 1.5 GeV protons on a thick lead target. Comparison between experimental data and Monte-Carlo simulations

International Nuclear Information System (INIS)

Krasa, A.; Krizek, F.; Wagner, V.; Kugler, A.; Henzl, V.; Henzlova, D.; Majerle, M.; Adam, J.; Caloun, P.; Bradnova, V.; Chultem, D.; Kalinnikov, V.G.; Krivopustov, M.I.; Solnyshkin, A.A.; Stegajlov, V.I.; Tsupko-Sitnikov, V.M.; Tumehndehlgehr, Ts.; Vasil'ev, S.I.

2005-01-01

This paper reports on two experiments performed at the Synchrophasotron/Nuclotron accelerator complex at JINR. Relativistic protons with energies 885 MeV and 1.5 GeV hit a massive cylindrical lead target. The spatial and energetic distributions of the neutron field produced by the spallation reactions were measured by the activation of Al, Au, Bi, Co, and Cu foils placed on the surface of the target and close to it. The yields of the radioactive nuclei produced by threshold reactions in these foils were determined by the analyses of their γ spectra. The comparison with Monte-Carlo based simulations was performed both with the LAHET+MCNP code and the MCNPX code

Lead Polluted Hotspot: Environmental Implication of Unplanned Industrial Development

Directory of Open Access Journals (Sweden)

Rikta Sharmin Yousuf

2016-06-01

Full Text Available In Rayer Bazaar, different industries like tannery, plastic, textile, battery recycling industry etc. are increasing rapidly without considering the environmental issues and deterioration. Since chromium (Cr pollution of this area has been widely investigated due to the presence of tannery industries, this study was focused on examining other environmental factors. Field visits and analytical results of semi-quantitative and quantitative analysis as well as three dimensional excitation emission matrix spectroscopy (3DEEM of water, soil and vegetative tissues indicated that, the area is highly polluted in term of different environmental parameters and metal content. The extremely high lead (Pb content of the soil (1171.7 mg/kg in summer, 2157.1 mg/kg in winter and blackish materials of vegetative tissues (6585.6 mg/kg in summer, 1974.1 mg/kg in winter indicates excessive lead deposition of this area that makes it a lead polluted hotspot. One of the possible sources of the extremely high lead concentration is adjacent battery recycling industry and/or other industries surrounding this area. So it is urgent to take necessary steps to find out immediate options for possible mitigation.

Interaction of a laser-breakdown plasma with a charged metallic target

International Nuclear Information System (INIS)

Vasil'ev, B.I.; Grasyuk, A.Z.; Dyad'kin, A.P.; Sukhanov, A.N.

1981-01-01

A study was made of the influence of a laser plasma on the potential of an insulated conducting target. It was discovered that the target potential changed stepwise on illumination with a high-power TEA CO 2 laser. A step, ΔU, in the target potential was observed and the dependences of ΔU on the initial potential, laser radiation energy density, and geometrical dimensions of the illuminated region were determined. There was an optimal pressure of the surrounding air for which ΔU had the maximum value. The dependence of ΔU on the pressure was determined, when illuminating a target in air and in nitrogen. The temporal characteristics of the variation in ΔU were correlated with the time variation of the visible and ultraviolet luminescence from the plasma. A mechanism was proposed to explain the potential step accompanying the interaction of a laser-produced plasma with a charged metallic target

Measurements of gas and volatile element production rates from an irradiated molten lead and lead-bismuth spallation target with proton beams of 1 and 1.4 GeV; Mesures de taux de production d'elements gazeux et volatiles lors de reactions induites par des protons de 1 et 1,4 GeV sur des cibles epaisses de plomb et plomb-bismuth liquides

Energy Technology Data Exchange (ETDEWEB)

Tall, Y

2008-03-15

The integrated project EUROTRANS (European Research Programme for the Transmutation of High Level Nuclear Waste in an Accelerator Driven System) of the 6. EURATOM Framework Programme aims to demonstrate the transmutation of radioactive waste in ADS (Accelerator Driven Sub-critical system). It will carry out a first advanced design of an experimental facility to demonstrate the technical feasibility of transmutation, and will produce a conceptual design of an industrial facility dedicated to transmutation. An ADS consists of three fundamental elements: the accelerator of protons, the sub-critical core and the spallation target. SUBATECH (physique Sub-Atomique et des Technologies associees) laboratory is involved to the study of the chosen liquid lead-bismuth as a spallation ADS target. The irradiation of liquid lead-bismuth target with energetic proton beam generates in addition to neutrons, volatile and radioactive residues. In order to determine experimentally the production rates of gas and volatile elements following a spallation reaction in a lead-bismuth target, the experiment IS419 was performed at the ISOLDE facility at CERN (Centre Europeen de la Recherche Nucleaire). This experiment constitutes the frame of the thesis whose main objective is to assess and study the production and release rates of many gas and volatile element from the irradiated lead-bismuth target with an energetic proton beam. The obtained data are compared to Monte Carlo simulation code (MCNPX) results in order to test the intranuclear cascade model of Bertini and of Cugnon, and the evaporation options of Dresner and Schmidt. (author)

Review of Ordered Anarchy: Jasay and his Surroundings

Directory of Open Access Journals (Sweden)

Aschwin de Wolf

2009-02-01

Full Text Available Anthony de Jasay is among the most important social thinkers of our time. His oeuvre offers a sustained critique of government and its defenders. In the book Ordered Anarchy: Jasay and His Surroundings, colleagues and friends pay tribute to the man in the form of an inspiring collection of essays.

Development of the HERA-Β-target-control system and study of target operation at the HERA storage ring

International Nuclear Information System (INIS)

Issever, S.

2001-03-01

The HERA-B experiment investigates the physics of heavy quarks, which are produced in pN reactions of the 920 GeV protons of HERA with the HERA-B internal fixed target. It consists out of eight wires, which surround the proton beam from four sides and is a high luminosity particle source. As being the closest mechanical device to the proton beam, it has to be operated very carefully and thus needs a secure and automatic control system, which additionally must be efficient and reliable to guarantee an efficient HERA-B data taking. The implementation of the target control system and its performance as well as dedicated studies of target-beam physics are presented. These include the measurement of the aperture limitation, usual target operational position, target efficiency, target independent proton loss in HERA and the scrape velocity of the target. The source of rate fluctuations is investigated in detail; among many dependencies environmental noise has a major impact on the rate fluctuations. Further studies include the analysis of beam position fluctuations and its correlation to the rate fluctuations; the rate changes about a factor of 2, if the beam is changing its position by 10 μm. This rate sensitivity is also verified directly by means of step function measurements. Furthermore the step function measurements can be used to study target-beam dynamics on time scales as short as a second. Experiments to reduce the rate sensitivity - the so called beam tail shaping measurements - are presented as well. During target operation a current, which is proportional to the interaction rate, is measured and used to determine the rate of each single wire. It is shown, that the source of this current is delta electron production. Finally the multiwire performance of the target control system is presented. (orig.)

SU-E-J-142: Prompt Gamma Emission Measurements From a Passively Scattered Proton Beam On Targets Containing 16O, 12C and 14N

Energy Technology Data Exchange (ETDEWEB)

Jeyasugiththan, J [Department of Physics, University of Cape Town, Cape Town (South Africa); Department of Clinical Oncology, Teaching Hospital, Jeffna (Sri Lanka); Peterson, S [Department of Physics, University of Cape Town, Cape Town (South Africa)

2015-06-15

Purpose: To measure the prompt gamma emission from the important elements found in tissue ({sup 16}O,{sup 12}C and {sup 14}N) in a clinical passive-scatter treatment environment. Methods: The targets (composed of water, Perspex, graphite and liquid nitrogen) were irradiated with a 200 MeV passive-scatter proton beam and the discrete prompt gamma energy spectra was detected by a high resolution 2′ × 2′ LaBr. detector. In order to reduce the high level of radiation produced by the beam line elements, the detector was surrounded by 10 cm of lead to attenuate the scattered gamma-rays entering the detector with an extra 5 cm thick layer of lead added along the beam direction. A 10 cm thick collimator with a 5 cm × 10 cm rectangular opening was also used. Results: The prompt gamma peaks at 6.13 MeV and 4.44 MeV were clearly identified as a Result of the inelastic nuclear reaction between the protons and the 16O atoms found in the water target. The 6.13 MeV peak was 5% higher than the peak at 4.44 MeV for the water target. The 4.44 MeV peak was the only identified emission in the prompt gamma energy spectra from the graphite target ({sup 12}C). The expected 2.313 MeV peak form the{sup 14}N (liquid nitrogen target) was identified, but the other expected {sup 14}N peaks could not be resolved. Conclusion: Prompt gamma measurements with a passive-scatter proton beam are possible, but the presence of a high amount of background radiation from the patient final collimator presents a challenge at the treatment isocenter. The prominent prompt gamma peaks at 6.13 MeV and 4.44 MeV were identified from the water, Perspex and graphite targets. The prompt gammas from the liquid nitrogen target were difficult to see, but may not be significant in the in-vivo verification process.

A permeability barrier surrounds taste buds in lingual epithelia

Science.gov (United States)

Dando, Robin; Pereira, Elizabeth; Kurian, Mani; Barro-Soria, Rene; Chaudhari, Nirupa

2014-01-01

Epithelial tissues are characterized by specialized cell-cell junctions, typically localized to the apical regions of cells. These junctions are formed by interacting membrane proteins and by cytoskeletal and extracellular matrix components. Within the lingual epithelium, tight junctions join the apical tips of the gustatory sensory cells in taste buds. These junctions constitute a selective barrier that limits penetration of chemosensory stimuli into taste buds (Michlig et al. J Comp Neurol 502: 1003–1011, 2007). We tested the ability of chemical compounds to permeate into sensory end organs in the lingual epithelium. Our findings reveal a robust barrier that surrounds the entire body of taste buds, not limited to the apical tight junctions. This barrier prevents penetration of many, but not all, compounds, whether they are applied topically, injected into the parenchyma of the tongue, or circulating in the blood supply, into taste buds. Enzymatic treatments indicate that this barrier likely includes glycosaminoglycans, as it was disrupted by chondroitinase but, less effectively, by proteases. The barrier surrounding taste buds could also be disrupted by brief treatment of lingual tissue samples with DMSO. Brief exposure of lingual slices to DMSO did not affect the ability of taste buds within the slice to respond to chemical stimulation. The existence of a highly impermeable barrier surrounding taste buds and methods to break through this barrier may be relevant to basic research and to clinical treatments of taste. PMID:25209263

A permeability barrier surrounds taste buds in lingual epithelia.

Science.gov (United States)

Dando, Robin; Pereira, Elizabeth; Kurian, Mani; Barro-Soria, Rene; Chaudhari, Nirupa; Roper, Stephen D

2015-01-01

Epithelial tissues are characterized by specialized cell-cell junctions, typically localized to the apical regions of cells. These junctions are formed by interacting membrane proteins and by cytoskeletal and extracellular matrix components. Within the lingual epithelium, tight junctions join the apical tips of the gustatory sensory cells in taste buds. These junctions constitute a selective barrier that limits penetration of chemosensory stimuli into taste buds (Michlig et al. J Comp Neurol 502: 1003-1011, 2007). We tested the ability of chemical compounds to permeate into sensory end organs in the lingual epithelium. Our findings reveal a robust barrier that surrounds the entire body of taste buds, not limited to the apical tight junctions. This barrier prevents penetration of many, but not all, compounds, whether they are applied topically, injected into the parenchyma of the tongue, or circulating in the blood supply, into taste buds. Enzymatic treatments indicate that this barrier likely includes glycosaminoglycans, as it was disrupted by chondroitinase but, less effectively, by proteases. The barrier surrounding taste buds could also be disrupted by brief treatment of lingual tissue samples with DMSO. Brief exposure of lingual slices to DMSO did not affect the ability of taste buds within the slice to respond to chemical stimulation. The existence of a highly impermeable barrier surrounding taste buds and methods to break through this barrier may be relevant to basic research and to clinical treatments of taste. Copyright © 2015 the American Physiological Society.

Summertime ozone formation in Xi'an and surrounding areas, China

Directory of Open Access Journals (Sweden)

T. Feng

2016-04-01

Full Text Available In this study, the ozone (O3 formation in China's northwest city of Xi'an and surrounding areas is investigated using the Weather Research and Forecasting atmospheric chemistry (WRF-Chem model during the period from 22 to 24 August 2013, corresponding to a heavy air pollution episode with high concentrations of O3 and PM2.5. The model generally performs well compared to measurements in simulating the surface temperature, relative humidity, and wind speed and direction, near-surface O3 and PM2.5 mass concentrations, and aerosol constituents. High aerosol concentrations in Xi'an and surrounding areas significantly decrease the photolysis frequencies and can reduce O3 concentrations by more than 50 µg m−3 (around 25 ppb on average. Sensitivity studies show that the O3 production regime in Xi'an and surrounding areas is complicated, varying from NOx to VOC (volatile organic compound-sensitive chemistry. The industrial emissions contribute the most to the O3 concentrations compared to biogenic and other anthropogenic sources, but neither individual anthropogenic emission nor biogenic emission plays a dominant role in the O3 formation. Under high O3 and PM2.5 concentrations, a 50 % reduction in all the anthropogenic emissions only decreases near-surface O3 concentrations by about 14 % during daytime. The complicated O3 production regime and high aerosol levels pose a challenge for O3 control strategies in Xi'an and surrounding areas. Further investigation regarding O3 control strategies will need to be performed, taking into consideration the rapid changes in anthropogenic emissions that are not reflected in the current emission inventories and the uncertainties in the meteorological field simulations.

An oxygen-rich dust disk surrounding an evolved star in the Red Rectangle

NARCIS (Netherlands)

Waters, LBFM; Waelkens, C; van Winckel, H; Molster, FJ; Tielens, AGGM; van Loon, JT; Morris, PW; Cami, J; Bouwman, J; de Koter, A; de Jong, T; de Graauw, T

1998-01-01

The Red Rectangle(1) is the prototype of a class of carbon-rich reflection nebulae surrounding low-mass stars in the final stages of evolution. The central star of this nebula has ejected most of its layers (during the red-giant phase), which now form the surrounding cloud, and is rapidly evolving

Assessing Local and Surrounding Threats to the Protected Area Network in a Biodiversity Hotspot: The Hengduan Mountains of Southwest China.

Science.gov (United States)

Ye, Xin; Liu, Guohua; Li, Zongshan; Wang, Hao; Zeng, Yuan

2015-01-01

Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (pprotected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies.

Preliminary Design of the Liquid Lead Corrosion Test Loop

International Nuclear Information System (INIS)

Cho, Chung Ho; Cha, Jae Eun; Cho, Choon Ho; Song, Tae Yung; Kim, Hee Reyoung

2005-01-01

Recently, Lead-Bismuth Eutectic (LBE) or Lead has newly attracted considerable attraction as a coolant to get the more inherent safety. Above all, LBE is preferred as the coolant and target material for an Accelerator-Driven System (ADS) due to its high production rate of neutrons, effective heat removal, and good radiation damage properties. But, the LBE or Lead as a coolant has a challenging problem that the LBE or Lead is more corrosive to the construction materials and fuel cladding material than the sodium because the solubility of Ni, Cr and Fe is high. After all, the LBE or Lead corrosion has been considered as an important design limit factor of ADS and Liquid Metal cooled Fast Reactors (LMFR). The Korea Atomic Energy Research Institute (KAERI) has been developing an ADS called HYPER. HYPER is designed to transmute Transuranics (TRU), Tc-99 and I-129 coming from Pressurized Water Reactors (PWRs) and uses an LBE as a coolant and target material. Also, an experimental apparatuses for the compatibility of fuel cladding and structural material with the LBE or Lead are being under the construction or design. The main objective of the present paper is introduction of Lead corrosion test loop which will be built the upside of the LBE corrosion test loop by the end of October of 2005

Differentiation in native as well as introduced ranges: germination reflects mean and variance in cover of surrounding vegetation.

Science.gov (United States)

Heger, Tina; Nikles, Gabriele; Jacobs, Brooke S

2018-02-01

Germination, a crucial phase in the life cycle of a plant, can be significantly influenced by competition and facilitation. The aim of this study was to test whether differences in cover of surrounding vegetation can lead to population differentiation in germination behaviour of an annual grassland species, and if so, whether such a differentiation can be found in the native as well as in the introduced range. We used maternal progeny of Erodium cicutarium previously propagated under uniform conditions that had been collected in multiple populations in the native and two introduced ranges, in populations representing extremes in terms of mean and variability of the cover of surrounding vegetation. In the first experiment, we tested the effect of germination temperature and mean cover at the source site on germination, and found interlinked effects of these factors. In seeds from one of the introduced ranges (California), we found indication for a 2-fold dormancy, hindering germination at high temperatures even if physical dormancy was broken and water was available. This behaviour was less strong in high cover populations, indicating cross-generational facilitating effects of dense vegetation. In the second experiment, we tested whether spatial variation in cover of surrounding vegetation has an effect on the proportion of dormant seeds. Contrary to our expectations, we found that across source regions, high variance in cover was associated with higher proportions of seeds germinating directly after storage. In all three regions, germination seemed to match the local environment in terms of climate and vegetation cover. We suggest that this is due to a combined effect of introduction of preadapted genotypes and local evolutionary processes.

Experimental study of the features of the running part liquid metal target on lead-bismuth alloy

International Nuclear Information System (INIS)

Beznosov, A.V.; Meluzov, A.G.; Novozhilova, O.O.; Efanov, A.D.

2007-01-01

The results of experimental investigations of the through part of a full-scale liquid metal target of an accelerator-control system, where the working cavity of the target communicates directly with the particle accelerator cavity, are presented. Two design variants were investigated - with vertical and horizontal orientation of the target axis in space and spinning of the flow in front of the nozzle adapter located in front of the entrance of the eutectic into the working cavity of the target. The profiles obtained for the free coolant surface with liquid metal flowing through vertically and horizontally positioned targets are presented. It is confirmed that when the pressure of the free surface of the liquid metal corresponds to the pressure in the accelerator cavity it is possible that liquid metal will not flow into the cavity simulating the connecting piece for inflow of accelerated particles with the piece oriented vertically or horizontally [ru

Thermal-hydraulics investigations for the Liquid Lead-Bismuth Target of the SINQ spallation source

International Nuclear Information System (INIS)

Sigg, B.; Dury, T.; Hudina, M.; Smith, B.

1991-01-01

The paper contains a discussion of the thermal-hydraulic problems of the target which require detailed analysis by means of a two- or three-dimensional space- and in part also time-dependent fluid dynamics code. There follows a short description of the general-purpose code ASTEC, which is being used for these investigations, and examples of the target modelling, including results. The final part of the paper is devoted to a short discussion of experiments against which this application of the code has to be validated. (author)

Numerical Simulation on Zonal Disintegration in Deep Surrounding Rock Mass

Directory of Open Access Journals (Sweden)

Xuguang Chen

2014-01-01

Full Text Available Zonal disintegration have been discovered in many underground tunnels with the increasing of embedded depth. The formation mechanism of such phenomenon is difficult to explain under the framework of traditional rock mechanics, and the fractured shape and forming conditions are unclear. The numerical simulation was carried out to research the generating condition and forming process of zonal disintegration. Via comparing the results with the geomechanical model test, the zonal disintegration phenomenon was confirmed and its mechanism is revealed. It is found to be the result of circular fracture which develops within surrounding rock mass under the high geostress. The fractured shape of zonal disintegration was determined, and the radii of the fractured zones were found to fulfill the relationship of geometric progression. The numerical results were in accordance with the model test findings. The mechanism of the zonal disintegration was revealed by theoretical analysis based on fracture mechanics. The fractured zones are reportedly circular and concentric to the cavern. Each fracture zone ruptured at the elastic-plastic boundary of the surrounding rocks and then coalesced into the circular form. The geometric progression ratio was found to be related to the mechanical parameters and the ground stress of the surrounding rocks.

Numerical simulation on zonal disintegration in deep surrounding rock mass.

Science.gov (United States)

Chen, Xuguang; Wang, Yuan; Mei, Yu; Zhang, Xin

2014-01-01

Zonal disintegration have been discovered in many underground tunnels with the increasing of embedded depth. The formation mechanism of such phenomenon is difficult to explain under the framework of traditional rock mechanics, and the fractured shape and forming conditions are unclear. The numerical simulation was carried out to research the generating condition and forming process of zonal disintegration. Via comparing the results with the geomechanical model test, the zonal disintegration phenomenon was confirmed and its mechanism is revealed. It is found to be the result of circular fracture which develops within surrounding rock mass under the high geostress. The fractured shape of zonal disintegration was determined, and the radii of the fractured zones were found to fulfill the relationship of geometric progression. The numerical results were in accordance with the model test findings. The mechanism of the zonal disintegration was revealed by theoretical analysis based on fracture mechanics. The fractured zones are reportedly circular and concentric to the cavern. Each fracture zone ruptured at the elastic-plastic boundary of the surrounding rocks and then coalesced into the circular form. The geometric progression ratio was found to be related to the mechanical parameters and the ground stress of the surrounding rocks.

Tissue reaction surrounding miniscrews for orthodontic anchorage: An animal experiment

Directory of Open Access Journals (Sweden)

Stephanie Shih-Hsuan Chen

2012-03-01

Results and conclusions: (1 Tissue surrounding roots damaged by a miniscrew showed a significant inflammatory response. (2 Root resorption was occasionally observed after 3 weeks following insertion of a miniscrew even if the miniscrew was not in direct contact with the root. (3 Root repair was noted with a cementoblast lining along the resorption surface at as early as 3 weeks after miniscrew insertion. Alveolar bone filled in the lesion when the root damage was large so that the contour of the alveolar bone followed that of the damaged root, with the width of the periodontal ligament space being maintained. (4 Stable miniscrews were mainly those which did not contact adjacent roots, and for which the surrounding tissue showed only a small inflammatory response with some extent of direct bone contact around the miniscrew. On the contrary, most of the failed miniscrews were those which had direct contact with adjacent roots, and which exhibited severe tissue inflammation and were covered by thick layers of soft tissue. Failure was detected 3 weeks after insertion. Surprisingly, the epithelial lining surrounding the miniscrews might not have spontaneously resolved 6 weeks after screw removal. Persistent infection in the sinus tract was noted, and this would require attention.

Recognition of upper airway and surrounding structures at MRI in pediatric PCOS and OSAS

Science.gov (United States)

Tong, Yubing; Udupa, J. K.; Odhner, D.; Sin, Sanghun; Arens, Raanan

2013-03-01

Obstructive Sleep Apnea Syndrome (OSAS) is common in obese children with risk being 4.5 fold compared to normal control subjects. Polycystic Ovary Syndrome (PCOS) has recently been shown to be associated with OSAS that may further lead to significant cardiovascular and neuro-cognitive deficits. We are investigating image-based biomarkers to understand the architectural and dynamic changes in the upper airway and the surrounding hard and soft tissue structures via MRI in obese teenage children to study OSAS. At the previous SPIE conferences, we presented methods underlying Fuzzy Object Models (FOMs) for Automatic Anatomy Recognition (AAR) based on CT images of the thorax and the abdomen. The purpose of this paper is to demonstrate that the AAR approach is applicable to a different body region and image modality combination, namely in the study of upper airway structures via MRI. FOMs were built hierarchically, the smaller sub-objects forming the offspring of larger parent objects. FOMs encode the uncertainty and variability present in the form and relationships among the objects over a study population. Totally 11 basic objects (17 including composite) were modeled. Automatic recognition for the best pose of FOMs in a given image was implemented by using four methods - a one-shot method that does not require search, another three searching methods that include Fisher Linear Discriminate (FLD), a b-scale energy optimization strategy, and optimum threshold recognition method. In all, 30 multi-fold cross validation experiments based on 15 patient MRI data sets were carried out to assess the accuracy of recognition. The results indicate that the objects can be recognized with an average location error of less than 5 mm or 2-3 voxels. Then the iterative relative fuzzy connectedness (IRFC) algorithm was adopted for delineation of the target organs based on the recognized results. The delineation results showed an overall FP and TP volume fraction of 0.02 and 0.93.

Method for the irradiation of single targets

International Nuclear Information System (INIS)

Krimmel, E.; Dullnig, H.

1977-01-01

The invention pertains to a system for the irradiation of single targets with particle beams. The targets all have frames around them. The system consists of an automatic advance leading into a high-vacuum chamber, and a positioning element which guides one target after the other into the irradiation position, at right angles to the automatic advance, and back into the automatic advance after irradiation. (GSCH) [de

Protective efficacy of Emblica against radiation and lead induced biochemical changes in the kidney of Swiss albino mice

International Nuclear Information System (INIS)

Chakrawarti, Aruna; Dev, Rahul; Rathore, Narendra Singh; Khatri, Anand

2012-01-01

Ionizing radiation kills cells in the area being treated (the target tissue) as well as other surrounding healthy cells. The damaging effects of ionizing radiation on healthy tissue create a major barrier in effective treatment of common human cancers. Thus there is a need to find a safe and highly effective avenue to reduce normal cell damage during cancer therapy, plants have been used in the traditional healthcare system from time immemorial, and phyto products continue to play an essential role in medicine. Emblica, is reported to have an excellent radio protective activity, antioxidant and a free radical scavenger. In light of above, the present study was aimed to evaluate the protective effect of Emblica against radiation and lead induced biochemical alterations in the kidney of Swiss albino mice. The animals were exposed to 6.0 Gy of gamma rays with or without Lead acetate treatment. The Emblica was administered seven days prior to irradiation or Lead Acetate treatment. The animals from all experimental groups were sacrificed by cervical dislocation at each post treatment intervals of 1, 2, 4, 7, 14 and 28 days. After sacrificing the animals, pieces of the kidney were taken out and kept at - 20 deg C for different biochemical parameters. For the study the animals were exposed to 6.0 Gy of gamma rays with or without Lead acetate treatments. In the experimental groups the Emblica juice was given seven days prior to the radiation or lead acetate treatment. The various biochemical parameters viz, total proteins, glycogen, cholesterol, acid phosphatase and alkaline phosphatase activities, DNA and RNA were estimated. The values were observed in the form of increase or decrease. After combined treatment of radiation and lead acetate the changes were more severe showing synergistic effect of both the agent. An early and fast recovery was also noticed in Emblica pre-treated animals. Thus it appears that Emblica is potent enough to check Lead and Radiation induced

Neutron production from 40 GeV/c mixed proton/pion beam on copper, silver and lead targets in the angular range 30-135 deg

Energy Technology Data Exchange (ETDEWEB)

Agosteo, S. [Dipartimento di Ingegneria Nucleare, Politecnico di Milano, via Ponzio 34/3, 20133 Milan (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milan (Italy); Birattari, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milan (Italy); Universita degli Studi di Milano, Dipartimento di Fisica, via Celoria 16, 20133 Milan (Italy); Dimovasili, E. [CERN, 1211 Geneva 23 (Switzerland); Foglio Para, A. [Dipartimento di Ingegneria Nucleare, Politecnico di Milano, via Ponzio 34/3, 20133 Milan (Italy); Silari, M. [CERN, 1211 Geneva 23 (Switzerland)]. E-mail: marco.silari@cern.ch; Ulrici, L. [CERN, 1211 Geneva 23 (Switzerland); Vincke, H. [CERN, 1211 Geneva 23 (Switzerland)

2005-02-01

The neutron emission from 50 mm thick copper, silver and lead targets bombarded by a mixed proton/pion beam with momentum of 40 GeV/c were measured at the CERN Super Proton Synchrotron. The neutron yield and spectral fluence per incident particle on target were measured with an extended range Bonner sphere spectrometer in the angular range 30-135 deg with respect to the beam direction. Monte Carlo simulations with the FLUKA code were performed to provide a priori information for the unfolding of the experimental data. The spectral fluences show two peaks, an isotropic evaporation component centred at 3 MeV and a high-energy peak sitting around 100-150 MeV. The experimental neutron yields are given in four energy bins: <100 keV, 0.1-20 MeV, 20-500 MeV and 0.5-2 GeV. The total yields show a systematic discrepancy of 30-50%, with a peak of 70% at the largest angles, with respect to the results of the Monte Carlo simulations, which it is believed to be mainly due to uncertainties in the beam normalization factor. Analytic expressions are given for the variation of the integral yield as a function of emission angle and of target mass number.

Neutron production from 40 GeV/c mixed proton/pion beam on copper, silver and lead targets in the angular range 30-135 deg

International Nuclear Information System (INIS)

Agosteo, S.; Birattari, C.; Dimovasili, E.; Foglio Para, A.; Silari, M.; Ulrici, L.; Vincke, H.

2005-01-01

The neutron emission from 50 mm thick copper, silver and lead targets bombarded by a mixed proton/pion beam with momentum of 40 GeV/c were measured at the CERN Super Proton Synchrotron. The neutron yield and spectral fluence per incident particle on target were measured with an extended range Bonner sphere spectrometer in the angular range 30-135 deg with respect to the beam direction. Monte Carlo simulations with the FLUKA code were performed to provide a priori information for the unfolding of the experimental data. The spectral fluences show two peaks, an isotropic evaporation component centred at 3 MeV and a high-energy peak sitting around 100-150 MeV. The experimental neutron yields are given in four energy bins: <100 keV, 0.1-20 MeV, 20-500 MeV and 0.5-2 GeV. The total yields show a systematic discrepancy of 30-50%, with a peak of 70% at the largest angles, with respect to the results of the Monte Carlo simulations, which it is believed to be mainly due to uncertainties in the beam normalization factor. Analytic expressions are given for the variation of the integral yield as a function of emission angle and of target mass number

Neutron production from 40 GeV/c mixed proton/pion beam on copper, silver and lead targets in the angular range 30-135°

Science.gov (United States)

Agosteo, S.; Birattari, C.; Dimovasili, E.; Foglio Para, A.; Silari, M.; Ulrici, L.; Vincke, H.

2005-02-01

The neutron emission from 50 mm thick copper, silver and lead targets bombarded by a mixed proton/pion beam with momentum of 40 GeV/c were measured at the CERN Super Proton Synchrotron. The neutron yield and spectral fluence per incident particle on target were measured with an extended range Bonner sphere spectrometer in the angular range 30-135° with respect to the beam direction. Monte Carlo simulations with the FLUKA code were performed to provide a priori information for the unfolding of the experimental data. The spectral fluences show two peaks, an isotropic evaporation component centred at 3 MeV and a high-energy peak sitting around 100-150 MeV. The experimental neutron yields are given in four energy bins: <100 keV, 0.1-20 MeV, 20-500 MeV and 0.5-2 GeV. The total yields show a systematic discrepancy of 30-50%, with a peak of 70% at the largest angles, with respect to the results of the Monte Carlo simulations, which it is believed to be mainly due to uncertainties in the beam normalization factor. Analytic expressions are given for the variation of the integral yield as a function of emission angle and of target mass number.

ATW neutron spectrum measurements at LAMPF

Energy Technology Data Exchange (ETDEWEB)

Butler, G.W.; Littleton, P.E.; Morgan, G.L. [Los Alamos National Laboratory, NM (United States)] [and others

1995-10-01

Accelerator transmutation of waste (ATW) is a proposal to use a high flux of accelerator-produced thermalized neutrons to transmute both fission product and higher actinide commercial nuclear waste into stable or short-lived radioactive species in order to avoid long-term storage of nuclear waste. At LAMPF the authors recently performed experiments that were designed to measure the spectrum of neutrons produced per incident proton for full-scale proposed ATW targets of lead and lithium. The neutrons produced in such targets have a spectrum of energies that extends up to the energy of the incident proton beam, but the distribution peaks between 1 and 5 MeV. Transmutation reactions and fission of actinides are most efficient when the neutron energy is below a few eV, so the target must be surrounded by a non-absorbing material (blanket) to produce additional neutrons and reduce the energy of high energy neutrons without loss. The experiments with the lead target, 25 cm diameter by 40 cm long, were conducted with 800 MeV protons, while those with the lithium target, 25 cm diameter by 175 cm long, were conducted with 400 MeV protons. The blanket in both sets of experiments was a 60 cm diameter by 200 cm long annulus of lead that surrounded the target. Surrounding the blanket was a steel water tank with dimensions of 250 cm diameter by 300 cm long that simulated the transmutation region. A small sample pipe penetrated the length of the lead blanket and other sample pipes penetrated the length of the water tank at different radii from the beam axis so that the neutron spectra at different locations could be measured by foil activation. After irradiation the activated foil sets were extracted and counted with calibrated high resolution germanium gamma ray detectors at the Los Alamos nuclear chemistry counting facility.

An acclerator-based installation of small power with the lead-bismuth coolant

Energy Technology Data Exchange (ETDEWEB)

Gorshkov, V.T.; Yefimov, E.I.; Novikova, N.N. [Research and Development Bereau, Podolsk (Russian Federation)] [and others

1995-10-01

The structure of the accelerator-based installation is described that includes the subcritical reactor-blanket with power 15 MW(h) cooled with lead-bismuth, the lead-bismuth flow target where a beam of {alpha}-particle is injected, the equipment of a primary and secondary curcuits. Some results of calculations and estimations are discussed that have been carried out to justify the target and blanket constructions. Some main characteristics of the installation are presented.

Calor e trabalho: são estes conceitos invariantes sob a permuta sistema-vizinhança? Heat and work concepts: are they invariant under a system-surroundings interchange?

Directory of Open Access Journals (Sweden)

Joaquim Anacleto

2008-01-01

Full Text Available It is argued that the invariants associated to the First Law of Thermodynamics and to the concept of identical processes lead to a clear definition of heat and work. The conditions for heat and work to be invariant under a system-surroundings interchange are also investigated. Finally, examples are presented to illustrate the above conditions.

Feature extraction for SAR target recognition based on supervised manifold learning

International Nuclear Information System (INIS)

Du, C; Zhou, S; Sun, J; Zhao, J

2014-01-01

On the basis of manifold learning theory, a new feature extraction method for Synthetic aperture radar (SAR) target recognition is proposed. First, the proposed algorithm estimates the within-class and between-class local neighbourhood surrounding each SAR sample. After computing the local tangent space for each neighbourhood, the proposed algorithm seeks for the optimal projecting matrix by preserving the local within-class property and simultaneously maximizing the local between-class separability. The use of uncorrelated constraint can also enhance the discriminating power of the optimal projecting matrix. Finally, the nearest neighbour classifier is applied to recognize SAR targets in the projected feature subspace. Experimental results on MSTAR datasets demonstrate that the proposed method can provide a higher recognition rate than traditional feature extraction algorithms in SAR target recognition

Ginger components as new leads for the design and development of novel multi-targeted anti-Alzheimer’s drugs: a computational investigation

Directory of Open Access Journals (Sweden)

Azam F

2014-10-01

Full Text Available Faizul Azam,1,2 Abdualrahman M Amer,1 Abdullah R Abulifa,1 Mustafa M Elzwawi1 1Faculty of Pharmacy, Misurata University, Misurata, Libya; 2Department of Pharmaceutical Chemistry, Nims Institute of Pharmacy, Nims University, Jaipur, Rajasthan, India Abstract: Ginger (Zingiber officinale, despite being a common dietary adjunct that contributes to the taste and flavor of foods, is well known to contain a number of potentially bioactive phytochemicals having valuable medicinal properties. Although recent studies have emphasized their benefits in Alzheimer’s disease, limited information is available on the possible mechanism by which it renders anti-Alzheimer activity. Therefore, the present study seeks to employ molecular docking studies to investigate the binding interactions between active ginger components and various anti-Alzheimer drug targets. Lamarckian genetic algorithm methodology was employed for docking of 12 ligands with 13 different target proteins using AutoDock 4.2 program. Docking protocol was validated by re-docking of all native co-crystallized ligands into their original binding cavities exhibiting a strong correlation coefficient value (r2=0.931 between experimentally reported and docking predicted activities. This value suggests that the approach could be a promising computational tool to aid optimization of lead compounds obtained from ginger. Analysis of binding energy, predicted inhibition constant, and hydrophobic/hydrophilic interactions of ligands with target receptors revealed acetylcholinesterase as most promising, while c-Jun N-terminal kinase was recognized as the least favorable anti-Alzheimer’s drug target. Common structural requirements include hydrogen bond donor/acceptor area, hydrophobic domain, carbon spacer, and distal hydrophobic domain flanked by hydrogen bond donor/acceptor moieties. In addition, drug-likeness score and molecular properties responsible for a good pharmacokinetic profile were calculated

Target tailoring and proton beam therapy to reduce small bowel dose in cervical cancer radiotherapy. A comparison of benefits

International Nuclear Information System (INIS)

Boer, Peter de; Westerveld, Henrike; Smit, Mark; Bel, Arjan; Rasch, Coen R.N.; Stalpers, Lukas J.A.; Schoot, Agustinus J.A.J. van de; Buist, Marrije R.

2018-01-01

The aim of the study was to investigate the potential clinical benefit from both target tailoring by excluding the tumour-free proximal part of the uterus during image-guided adaptive radiotherapy (IGART) and improved dose conformity based on intensity-modulated proton therapy (IMPT). The study included planning CTs from 11 previously treated patients with cervical cancer with a >4-cm tumour-free part of the proximal uterus on diagnostic magnetic resonance imaging (MRI). IGART and robustly optimised IMPT plans were generated for both conventional target volumes and for MRI-based target tailoring (where the non-invaded proximal part of the uterus was excluded), yielding four treatment plans per patient. For each plan, the V 15Gy , V 30Gy , V 45Gy and D mean for bladder, sigmoid, rectum and bowel bag were compared, and the normal tissue complication probability (NTCP) for ≥grade 2 acute small bowel toxicity was calculated. Both IMPT and MRI-based target tailoring resulted in significant reductions in V 15Gy , V 30Gy , V 45Gy and D mean for bladder and small bowel. IMPT reduced the NTCP for small bowel toxicity from 25% to 18%; this was further reduced to 9% when combined with MRI-based target tailoring. In four of the 11 patients (36%), NTCP reductions of >10% were estimated by IMPT, and in six of the 11 patients (55%) when combined with MRI-based target tailoring. This >10% NTCP reduction was expected if the V 45Gy for bowel bag was >275 cm 3 and >200 cm 3 , respectively, during standard IGART alone. In patients with cervical cancer, both proton therapy and MRI-based target tailoring lead to a significant reduction in the dose to surrounding organs at risk and small bowel toxicity. (orig.) [de

Nuclear performance of target-blanket assemblies for electronuclear fuel production

International Nuclear Information System (INIS)

Alsmiller, R.G. Jr.; Gabriel, T.A.; Barish, J.

1978-01-01

The results of calculations of high energy transport carried out to evaluate the nuclear performance of several of the designs that have been proposed for electronuclear fuel production are presented. Topics covered include: results for 1-GeV protons and 1-GeV deuterons incident on a lithium target surrounded by a 238 U blanket; results for 1 GeV protons and 1-GeV deuterons incident on a thorium salt; results for 1-GeV protons, incident on a gas-cooled system fueled by either 238 UO 2 or 232 ThO 2 ; and results for protons in the energy range 0.5 to 10 GeV incident on a very large natural uranium target

Lateral propagation of fast electrons at the laser-irradiated target surfaces

International Nuclear Information System (INIS)

Li, Y T; Lin, X X; Liu, B C; Du, F; Wang, S J; Li, C; Zhou, M L; Zhang, L; Liu, X; Wang, J; Liu, X L; Chen, L M; Wang, Z H; Ma, J L; Wei, Z Y; Zhang, J; Liu, F; Liu, F

2010-01-01

Lateral propagation of fast electrons at the target surfaces irradiated by femtosecond intense laser pulses is measured by k α x-ray imaging technique when a preplasma is presented. An annular halo surrounding a bright spot is observed in the x-ray images when the scale length of the electron density is large. For an incidence angle of 70 0 the x-ray images show a non-symmetrical distribution peaked to the laser propagation direction. The x-ray photons in the halo are mainly excited by the fast electrons that flow in the preplasma when their paths intersect the high density regions near the target surface.

Feasibility Studies for Quarkonium Production at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC)

International Nuclear Information System (INIS)

Hadjidakis, C.; Kikola, D.; Massacrier, L.; Trzeciak, B.; Lansberg, J. P.; Fleuret, F.; Shao, H.-S.

2015-01-01

Being used in the fixed-target mode, the multi-TeV LHC proton and lead beams allow for studies of heavy-flavour hadroproduction with unprecedented precision at backward rapidities, far negative Feynman-x, using conventional detection techniques. At the nominal LHC energies, quarkonia can be studied in detail in p+p, p+d, and p+A collisions at √(s_N_N)≃115 GeV and in Pb + p and Pb + A collisions at √(s_N_N)≃72 GeV with luminosities roughly equivalent to that of the collider mode that is up to 20 fb"−"1 yr"−"1 in p+p and p+d collisions, up to 0.6 fb"−"1 yr"−"1 in p+A collisions, and up to 10 nb"−"1 yr"−"1 in Pb + A collisions. In this paper, we assess the feasibility of such studies by performing fast simulations using the performance of a LHCb-like detector.

Feasibility studies for quarkonium production at a fixed-target experiment using the LHC proton and lead beams (AFTER@LHC)

CERN Document Server

Massacrier, L; Fleuret, F; Hadjidakis, C; Kikola, D; Lansberg, J P; Shao, H -S

2015-01-01

Used in the fixed-target mode, the multi-TeV LHC proton and lead beams allow for studies of heavy-flavour hadroproduction with unprecedented precision at backward rapidities - far negative Feyman-x - using conventional detection techniques. At the nominal LHC energies, quarkonia can be studies in detail in p+p, p+d and p+A collisions at sqrt(s_NN) ~ 115 GeV as well as in Pb+p and Pb+A collisions at sqrt(s_NN) ~ 72 GeV with luminosities roughly equivalent to that of the collider mode, i.e. up to 20 fb-1 yr-1 in p+p and p+d collisions, up to 0.6 fb-1 yr-1 in p+A collisions and up to 10 nb-1 yr-1 in Pb+A collisions. In this paper, we assess the feasibility of such studies by performing fast simulations using the performance of a LHCb-like detector.

Energy buildup factor for ICRU 33 sphere surrounded by an air layer

International Nuclear Information System (INIS)

Ochiana, G.; Oncescu, M.

1994-01-01

The buildup factor due to the air surrounding an ICRU 33 sphere is a desirable quantity in the assessment of the air kerma rate for external exposure to gamma emitters distributed on the ground. A Monte Carlo algorithm has been developed to perform the photon transport calculation within the air layer around the sphere. The energy buildup factor due to the air layer has been calculated for an extended radioactive source - the contaminated ground. The transport of photons within the air layer surrounding a sphere -ICRU 33 phantom - is done by calculating separately the energies deposited by photons into the sphere when this one is in vacuum and when it is surrounded by the air, respectively. The results are given for an air layer of 100 m thickness and photon energy between 0.01 and 3.0 MeV. (Author) 1 Fig., 1 Tab., 9 Refs

VESUVIUS PENTALOGUE: Interdisciplinary Science for Disaster Resilience and Sustainability of Populations Surrounding Vesuvius

Science.gov (United States)

Dobran, F.

2015-12-01

VESUVIUS PENTALOGUE is an elaboration of VESUVIUS 2000 scientific initiative aimed at volcanic risk reduction in the Vesuvius area. Its 5 building blocks are: (1) The current strategy of volcanic risk management (massive deportation of population) is both problematic and unacceptable. (2) A continuing close habitation of the population with the volcano should be the crucial cultural point to be pursued. This can be accomplished through a redefinition of the danger zone around Summa-Vesuvius as follows: (a) An exclusion nucleus should be established that prohibits all future human settlements and discourage the existing ones; (b) A resilience belt, housing most of the current population, should be established; (c) A sustainable area should be established beyond the resilience belt, allowing for both sustainable practices and temporary resettlements of the "resilience belt" citizens. (3) The built environment construction codes for the population of the danger zone should be established by utilizing Plinian eruption scenarios, scenario-based seismic hazard assessment and zonation, (c) dynamic structural analyses, (d) global volcanic simulations modeling of thermo-fluid dynamic eruption processes. (4) The volcanic risk information and education should involve an effective volcanic risk information campaign and active public preparedness strategy. This should be implemented for the exclusion nucleus, resilience belt, and sustainable area regions surrounding Summa-Vesuvius. A Volcanic Risk Education Safety Program should be implemented in all schools located within each of the above areas surrounding the volcano. (5)The political Authorities and the scientific community should produce a "memorandum of understanding" that univocally establishes an effective collaboration, and periodic progress reports that keep the populations informed on the improvements leading to the realization of the above objectives. For further details see www.gvess.org.

Application of Data Mining and Knowledge Discovery Techniques to Enhance Binary Target Detection and Decision-Making for Compromised Visual Images

National Research Council Canada - National Science Library

Repperger, D. W; Phillips, C. A; Schrider, C. D; Smith, E. A

2004-01-01

In an effort to improve decision-making on the identity of unknown objects appearing in visual images when the surrounding environment may be noisy and cluttered, a highly sensitive target detection...

An ISOLDE target unit

CERN Multimedia

Maximilien Brice

2002-01-01

A good dozen different targets are available for ISOLDE, made of different materials and equipped with different kinds of ion-sources, according to the needs of the experiments. Each separator (GPS: general purpose; HRS: high resolution) has its own target. Because of the high radiation levels, robots effect the target changes, about 80 times per year. In the standard unit shown in picture _01, the target is the cylindrical object in the front. It contains uranium-carbide kept at a temperature of 2200 deg C, necessary for the isotopes to be able to escape. At either end, one sees the heater current leads, carrying 700 A. The Booster beam, some 3E13 protons per pulse, enters the target from left. The evaporated isotope atoms enter a hot-plasma ion source (the black object behind the target). The whole unit sits at 60 kV potential (pulsed in synchronism with the arrival of the Booster beam) which accelerates the ions (away from the viewer) towards one of the 2 separators.

Gamma-Aminobutyric Acid Concentration is Reduced in Visual Cortex in Schizophrenia and Correlates with Orientation-Specific Surround Suppression

Science.gov (United States)

Yoon, Jong H.; Maddock, Richard J.; Rokem, Ariel; Silver, Michael A.; Minzenberg, Michael J.; Ragland, J. Daniel; Carter, Cameron S.

2010-01-01

The neural mechanisms underlying cognitive deficits in schizophrenia remain largely unknown. The gamma-aminobutyric acid (GABA) hypothesis proposes that reduced neuronal GABA concentration and neurotransmission results in cognitive impairments in schizophrenia. However, few in vivo studies have directly examined this hypothesis. We employed magnetic resonance spectroscopy (MRS) at high field to measure visual cortical GABA levels in 13 subjects with schizophrenia and 13 demographically matched healthy control subjects. We found that the schizophrenia group had an approximately 10% reduction in GABA concentration. We further tested the GABA hypothesis by examining the relationship between visual cortical GABA levels and orientation-specific surround suppression (OSSS), a behavioral measure of visual inhibition thought to be dependent on GABAergic synaptic transmission. Previous work has shown that subjects with schizophrenia exhibit reduced OSSS of contrast discrimination (Yoon et al., 2009). For subjects with both MRS and OSSS data (n=16), we found a highly significant positive correlation (r=0.76) between these variables. GABA concentration was not correlated with overall contrast discrimination performance for stimuli without a surround (r=-0.10). These results suggest that a neocortical GABA deficit in subjects with schizophrenia leads to impaired cortical inhibition and that GABAergic synaptic transmission in visual cortex plays a critical role in OSSS. PMID:20220012

The influence of the surrounding gas on drop impact onto a wet substrate

Science.gov (United States)

Deegan, Robert; Zhang, Li; Toole, Jameson

2011-11-01

The impact of a droplet with a wet or solid substrate creates a spray of secondary droplets. The effect of the surrounding gas on this process was widely neglected prior to the work of Xu, Zhang, & Nagel which showed that lowering the gas pressure suppresses splashing for impact with a dry solid substrate. Here we present the results of our experimental investigation of the effect of the surrounding gas on the evolution of splashes from a wet substrate. We varied the density and pressure of the surrounding gas. We find quantitative changes to the onset thresholds of splashing and on the size distribution of, but no qualitative changes. The effects are most pronounced on the evolution of the ejecta sheet.

Target-like pigmentation after minipunch grafting in stable vitiligo

Directory of Open Access Journals (Sweden)

Nelee Bisen

2014-01-01

Full Text Available Surgical treatment for vitiligo has been ever evolving. Each surgical modality has its own benefits and limitations. Miniature punch grafting is the most extensively performed surgery, which gives good results in stable vitiligo. Herein we report an unusual type of repigmentation observed after minipunch grafting in a patient of stable vitiligo, which resembled target-like lesions with a "perigraft halo" surrounding individual grafts. Such pigment spread occurred despite the use of 0.5 mm larger graft from the donor site.

Target area for Nova upgrade: Containing ignition and beyond

International Nuclear Information System (INIS)

Tobin, M.T.; Smith, J.R.; Campbell, D.; Wong, D.K.; Sullivan, J.A.; Pendergrass, J.; Weinstein, B.; Klein, M.

1991-01-01

The Lawrence Livermore National Laboratory (LLNL) is developing a conceptual design for upgrading the Nova laser from ∼ 50 kJ to ∼ 1.8 MJ of laser energy at a wavelength of 351 nm. Anticipated target performance includes achieving ignition and possibly fusion yields to 20 MJ. The target area design represents a unique challenge since it will be operating in a regime where first wall ablation and optics damage are major issues for the first time in an ICF facility. Here we describe potential performance criteria for the facility and anticipated yield-dependent x-ray, neutron, shrapnel, and debris environments. We also briefly describe the different systems that make up the target area and discuss some of the design issues. The insignificant environmental impact Nova Upgrade (NU) operations is anticipated to have on the laboratory and surrounding area is discussed. Finally, alternate design options are described along with their potential benefits

Opportunity's Surroundings on Sol 1818 (Vertical)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

Opportunity's Surroundings on Sol 1818 (Polar)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a polar projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

Minimizing driver errors: examining factors leading to failed target tracking and detection.

Science.gov (United States)

2013-06-01

Driving a motor vehicle is a common practice for many individuals. Although driving becomes : repetitive and a very habitual task, errors can occur that lead to accidents. One factor that can be a : cause for such errors is a lapse in attention or a ...

Cooperative tumour cell membrane targeted phototherapy

Science.gov (United States)

Kim, Heegon; Lee, Junsung; Oh, Chanhee; Park, Ji-Ho

2017-06-01

The targeted delivery of therapeutics using antibodies or nanomaterials has improved the precision and safety of cancer therapy. However, the paucity and heterogeneity of identified molecular targets within tumours have resulted in poor and uneven distribution of targeted agents, thus compromising treatment outcomes. Here, we construct a cooperative targeting system in which synthetic and biological nanocomponents participate together in the tumour cell membrane-selective localization of synthetic receptor-lipid conjugates (SR-lipids) to amplify the subsequent targeting of therapeutics. The SR-lipids are first delivered selectively to tumour cell membranes in the perivascular region using fusogenic liposomes. By hitchhiking with extracellular vesicles secreted by the cells, the SR-lipids are transferred to neighbouring cells and further spread throughout the tumour tissues where the molecular targets are limited. We show that this tumour cell membrane-targeted delivery of SR-lipids leads to uniform distribution and enhanced phototherapeutic efficacy of the targeted photosensitizer.

Drug-induced regulation of target expression

DEFF Research Database (Denmark)

Iskar, Murat; Campillos, Monica; Kuhn, Michael

2010-01-01

Drug perturbations of human cells lead to complex responses upon target binding. One of the known mechanisms is a (positive or negative) feedback loop that adjusts the expression level of the respective target protein. To quantify this mechanism systems-wide in an unbiased way, drug......-induced differential expression of drug target mRNA was examined in three cell lines using the Connectivity Map. To overcome various biases in this valuable resource, we have developed a computational normalization and scoring procedure that is applicable to gene expression recording upon heterogeneous drug treatments....... In 1290 drug-target relations, corresponding to 466 drugs acting on 167 drug targets studied, 8% of the targets are subject to regulation at the mRNA level. We confirmed systematically that in particular G-protein coupled receptors, when serving as known targets, are regulated upon drug treatment. We...

Target identification using Zernike moments and neural networks

Science.gov (United States)

Azimi-Sadjadi, Mahmood R.; Jamshidi, Arta A.; Nevis, Andrew J.

2001-10-01

The development of an underwater target identification algorithm capable of identifying various types of underwater targets, such as mines, under different environmental conditions pose many technical problems. Some of the contributing factors are: targets have diverse sizes, shapes and reflectivity properties. Target emplacement environment is variable; targets may be proud or partially buried. Environmental properties vary significantly from one location to another. Bottom features such as sand, rocks, corals, and vegetation can conceal a target whether it is partially buried or proud. Competing clutter with responses that closely resemble those of the targets may lead to false positives. All the problems mentioned above contribute to overly difficult and challenging conditions that could lead to unreliable algorithm performance with existing methods. In this paper, we developed and tested a shape-dependent feature extraction scheme that provides features invariant to rotation, size scaling and translation; properties that are extremely useful for any target classification problem. The developed schemes were tested on an electro-optical imagery data set collected under different environmental conditions with variable background, range and target types. The electro-optic data set was collected using a Laser Line Scan (LLS) sensor by the Coastal Systems Station (CSS), located in Panama City, Florida. The performance of the developed scheme and its robustness to distortion, rotation, scaling and translation was also studied.

Caving thickness effects of surrounding rocks macro stress shell evolving characteristics

Institute of Scientific and Technical Information of China (English)

XIE Guang-xiang; YANG Ke

2009-01-01

In order to explore the influence of different caving thicknesses on the MSS dis-tribution and evolving characteristics of surrounding rocks in unsymmetrical disposal and fully mechanized top-coal caving (FMTC), based on unsymmetrical disposal characteris-tics, the analyses of numerical simulation, material simulation and in-situ observation were synthetically applied according to the geological and technical conditions of the 1151(3) working face in Xieqiao Mine. The results show that the stress peak value of the MSS-base and the ratio of MSS-body height to caving thickness are nonlinear and inversely proportional to the caving thickness. The MSS-base width, the MSS-body height, the MSS-base distance to working face wall and the rise distance of MSS-base beside coal pillar are nonlinear and directly proportional to the caving thickness. The characteristics of MSS distribution and its evolving rules of surrounding rocks and the integrated caving thickness effects are obtained. The investigations will provide lots of theoretic references to the surrounding rocks' stability control of the working face and roadway, roadway layout, gas extraction and exploitation, and efficiency of caving, etc.

Study on water migration of tunnel surrounding rock in nuclear waste repository based on coupling theory

International Nuclear Information System (INIS)

Jiang Zhongming; Zhang Xinmin

2008-01-01

Excavation of tunnel changes not only the stresses and deformation of tunnel surrounding rock, but also disturbs the underground water environment in tunnel surrounding rock Water migration happens due to variation of pore water pressure and redistribution. Based on the mechanics of porous media, saturated and unsaturated hydro-mechanical coupling analysis method is employed to study the variation of the stresses, deformation and pore pressure of the surrounding rock. Case study indicates that the excavation of tunnel will induce redistribution of stress and pore water pressure. Redistribution of pore water pressure will seriously affect on evaluation of surrounding rock stability and diffusion of nucleon in the pore water. (authors)

Lead Adsorption into Activated Carbon: A Critical Review of the Literature

Science.gov (United States)

Lead has been widely used in many industries due to its desirable chemical and physical properties such as its malleability and resistance to corrosion. However, Lead poisoning is a serious health hazard that causes severe damage to multiple target organs including kidney, liver,...

Peripheral Contour Grouping and Saccade Targeting: The Role of Mirror Symmetry

Directory of Open Access Journals (Sweden)

Michaël Sassi

2014-01-01

Full Text Available Integrating shape contours in the visual periphery is vital to our ability to locate objects and thus make targeted saccadic eye movements to efficiently explore our surroundings. We tested whether global shape symmetry facilitates peripheral contour integration and saccade targeting in three experiments, in which observers responded to a successful peripheral contour detection by making a saccade towards the target shape. The target contours were horizontally (Experiment 1 or vertically (Experiments 2 and 3 mirror symmetric. Observers responded by making a horizontal (Experiments 1 and 2 or vertical (Experiment 3 eye movement. Based on an analysis of the saccadic latency and accuracy, we conclude that the figure-ground cue of global mirror symmetry in the periphery has little effect on contour integration or on the speed and precision with which saccades are targeted towards objects. The role of mirror symmetry may be more apparent under natural viewing conditions with multiple objects competing for attention, where symmetric regions in the visual field can pre-attentively signal the presence of objects, and thus attract eye movements.

Neutron source, linear-accelerator fuel enricher and regenerator and associated methods

Science.gov (United States)

Steinberg, Meyer; Powell, James R.; Takahashi, Hiroshi; Grand, Pierre; Kouts, Herbert

1982-01-01

A device for producing fissile material inside of fabricated nuclear elements so that they can be used to produce power in nuclear power reactors. Fuel elements, for example, of a LWR are placed in pressure tubes in a vessel surrounding a liquid lead-bismuth flowing columnar target. A linear-accelerator proton beam enters the side of the vessel and impinges on the dispersed liquid lead-bismuth columns and produces neutrons which radiate through the surrounding pressure tube assembly or blanket containing the nuclear fuel elements. These neutrons are absorbed by the natural fertile uranium-238 elements and are transformed to fissile plutonium-239. The fertile fuel is thus enriched in fissile material to a concentration whereby they can be used in power reactors. After use in the power reactors, dispensed depleted fuel elements can be reinserted into the pressure tubes surrounding the target and the nuclear fuel regenerated for further burning in the power reactor.

Effects of Surrounding Information and Line Length on Text Comprehension from the Web

Directory of Open Access Journals (Sweden)

Jess McMullin

2002-02-01

Full Text Available The World Wide Web (Web is becoming a popular medium for transmission of information and online learning. We need to understand how people comprehend information from the Web to design Web sites that maximize the acquisition of information. We examined two features of Web page design that are easily modified by developers, namely line length and the amount of surrounding information, or whitespace. Undergraduate university student participants read text and answered comprehension questions on the Web. Comprehension was affected by whitespace; participants had better comprehension for information surrounded by whitespace than for information surrounded by meaningless information. Participants were not affected by line length. These findings demonstrate that reading from the Web is not the same as reading print and have implications for instructional Web design.

Transmutation of 239Pu and other nuclides using spallation neutrons produced by relativistic protons reacting with massive U- and Pb- targets

International Nuclear Information System (INIS)

Adam, J.; Balabekyan, A.; Bamblevskij, V.P.

2001-01-01

Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as 129 I, 237 Np, and 239 Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory of High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV ≤ E(p) ≤ 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminium containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or 'energy amplifier') using a 10 mA proton beam of 1 GeV onto a Pb-target as used here, one can transmute in one gram samples of the isotope within one month about 3 mg 129 I, 21 mg 237 Np, 3.3 mg 238 U, and 200 mg 239 Pu under the same geometrical conditions. Our observations show, that the transmutation ability of our system increases linearly with the proton energy within the energy interval studied

Design of a cone target for fast ignition

Directory of Open Access Journals (Sweden)

Sunahara Atsushi

2013-11-01

Full Text Available We propose a new type of target for the fast ignition of inertial confinement fusion. Pre-formed plasma inside a cone target can significantly reduce the energy coupling efficiency from the ultra-high intense short-pulse laser to the imploded core plasma. Also, in order to protect the tip of the cone and reduce generation of pre-formed plasma, we propose pointed shaped cone target. In our estimation, the shock traveling time can be delayed 20–30 ps by lower-Z material with larger areal density compared to the conventional gold flat tip. Also, the jet flow can sweep the blow-off plasma from the tip of the cone, and the implosion performance is not drastically affected by the existence of pointed tip. In addition, the self-generated magnetic field is generated along the boundary of cone tip and surrounding CD or DT plasma. This magnetic field can confine fast electrons and focus to the implosion core plasma. Resultant heating efficiency is improved by 30% compared to that with conventional gold flat tip.

Spot testing on mechanical characteristics of surrounding rock in gates of fully mechanized top-coal caving face

Energy Technology Data Exchange (ETDEWEB)

Xie Guang-xiang; Yang Ke; Chang Ju-cai [Anhui University of Science and Technology, Anhui (China). Department of Resource Exploration and Management Engineering

2006-07-01

The distribution patterns of mechanical characteristics for surrounding rock in the gateways of fully mechanized top-coal caving (FMTC) face were put forward by analyzing deep displacement, surface displacement, stress distribution and supports loading. The results show that the surrounding rock of the gateways lies in abutment pressure decrease zone near the working face, so that the support load decreases. But the deformations of supports and surrounding rock are very acute. The deformation of surrounding rock appears mainly in abutment pressure influence zone. Reasonable roadway supporting should control the deformation of surrounding rock in intense stage of mining influence. Supporting design ideas of tailentry and head entry should be changed from loading control to deformation control. 8 refs., 10 figs., 1 tab.

Contamination of nebulisers and surrounding air at the bedside of ...

African Journals Online (AJOL)

An air sampler was used to collect air samples from the surrounding bedside environment. .... individualised resealable plastic bags and stored upside down in a cooler .... conventional and mesh technology nebulisers used at home by adults.

Phase-specific Surround suppression in Mouse Primary Visual Cortex Correlates with Figure Detection Behavior Based on Phase Discontinuity.

Science.gov (United States)

Li, Fengling; Jiang, Weiqian; Wang, Tian-Yi; Xie, Taorong; Yao, Haishan

2018-05-21

In the primary visual cortex (V1), neuronal responses to stimuli within the receptive field (RF) are modulated by stimuli in the RF surround. A common effect of surround modulation is surround suppression, which is dependent on the feature difference between stimuli within and surround the RF and is suggested to be involved in the perceptual phenomenon of figure-ground segregation. In this study, we examined the relationship between feature-specific surround suppression of V1 neurons and figure detection behavior based on figure-ground feature difference. We trained freely moving mice to perform a figure detection task using figure and ground gratings that differed in spatial phase. The performance of figure detection increased with the figure-ground phase difference, and was modulated by stimulus contrast. Electrophysiological recordings from V1 in head-fixed mice showed that the increase in phase difference between stimuli within and surround the RF caused a reduction in surround suppression, which was associated with an increase in V1 neural discrimination between stimuli with and without RF-surround phase difference. Consistent with the behavioral performance, the sensitivity of V1 neurons to RF-surround phase difference could be influenced by stimulus contrast. Furthermore, inhibiting V1 by optogenetically activating either parvalbumin (PV)- or somatostatin (SOM)-expressing inhibitory neurons both decreased the behavioral performance of figure detection. Thus, the phase-specific surround suppression in V1 represents a neural correlate of figure detection behavior based on figure-ground phase discontinuity. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Two short basic sequences surrounding the zinc finger of nucleocapsid protein NCp10 of Moloney murine leukemia virus are critical for RNA annealing activity.

Science.gov (United States)

De Rocquigny, H; Ficheux, D; Gabus, C; Allain, B; Fournie-Zaluski, M C; Darlix, J L; Roques, B P

1993-02-25

The 56 amino acid nucleocapsid protein (NCp10) of Moloney Murine Leukemia Virus, contains a CysX2CysX4HisX4Cys zinc finger flanked by basic residues. In vitro NCp10 promotes genomic RNA dimerization, a process most probably linked to genomic RNA packaging, and replication primer tRNA(Pro) annealing to the initiation site of reverse transcription. To characterize the amino-acid sequences involved in the various functions of NCp10, we have synthesized by solid phase method the native protein and a series of derived peptides shortened at the N- or C-terminus with or without the zinc finger domain. In the latter case, the two parts of the protein were linked by a Glycine - Glycine spacer. The in vitro studies of these peptides show that nucleic acid annealing activities of NCp10 do not require a zinc finger but are critically dependent on the presence of specific sequences located on each side of the CCHC domain and containing proline and basic residues. Thus, deletion of 11R or 49PRPQT, of the fully active 29 residue peptide 11RQGGERRRSQLDRDGGKKPRGPRGPRPQT53 leads to a complete loss of NCp10 activity. Therefore it is proposed that in NCp10, the zinc finger directs the spatial recognition of the target RNAs by the basic domains surrounding the zinc finger.

Molecular Targets for Targeted Radionuclide Therapy

International Nuclear Information System (INIS)

Mather, S.J.

2009-01-01

radiolabelled regulatory peptides and their metabolically stabilised analogues. Antigen epitopes: Antibodies, as unlabelled biological drugs, are becoming of increasing interest. They exert an antibody-dependent cellular cytotoxicity which leads to lysis of tumour cells. Radiolabelled versions of these (and other) antibodies are being developed worldwide. The disadvantage of the long circulating time of antibodies can be solved by engineering fragments such as diabodies, bivalent single chain variable fragments (scFv), minibodies or by pretargeting approaches. Transmembrane transporters: Other interesting targets are transporters for radiolabelled amino acids and nutrients. Cancer cells require an increased supply of many such nutrients and obtain these by increased expression of some types of amino-acid transporter. A more detailed analysis of the relationship between amino-acid uptake and transporter expression in normal and malignant cells would be very valuable in identifying the clinical therapeutic potential of this class of tracer. Tumour blood supply: Tumours require an efficient blood supply to grow and metastatise and active angiogenesis of new blood vessels is a feature of many tumours. Specific receptors expressed during this process represent a novel class of targets for TRT. Extra-cellular matrix: Recently, another relevant class of target antigens has raised interest. Lectins, or carbohydrate binding proteins, recognize specific oligosaccharide structures on glycoproteins and glycolipids. It is well known that protein and lipid glycosylation are consistently altered in cancer cells for the aberrant activity of specific glycosyltransferase and glycosydases. Experimental evidence demonstrated that tumor growth and progression may depend, at least in part, on the presence of altered glycoproteins on the cell surface, which can mediate aberrant receptor-ligand interactions. (author)

Differences in HIV-related behaviors at Lugufu refugee camp and surrounding host villages, Tanzania

Directory of Open Access Journals (Sweden)

Mbaruku Godfrey

2008-10-01

a protective factor. Most respondents knew where to go for HIV testing (84% of refugee respondents and 78% of respondents in surrounding villages, while more refugees than respondents from villages had ever been tested (42% vs. 22%, χ2 63.69, p = .000. Conclusion This research has important programmatic implications. Regardless of differences between camp and village populations, study results point to the need for targeted activities within each population. Services should include youth education and life skills programs emphasizing the benefits of delayed sexual initiation and the risks involved in transactional sex, especially in the camp where greater proportions of youth are affected by these issues relative to the surrounding host villages. As well, programs should stress the importance of correct and consistent condom use to increase usage in both populations. Further investigation into forced sex within regular partnerships, and programs that encourage male involvement in addressing this issue are needed. Program managers should verify that current commodity distribution systems ensure vulnerable women's access to resources, and consider additional program responses.

Application of radio-reagent method in the determination of lead trace amounts

International Nuclear Information System (INIS)

Figueiredo, A.M.G.

1983-01-01

A radiometric method for trace analysis of lead was established, based on the displacement reaction between lead and the complex cobalt - ethylenediaminetetracetate labelled with 60 Co (Co* - EDTA), which is named radioreagent. The radioactive cobalt displaced by lead is separated from the excess of radioreagent by the solvent extraction technique, using a solution of tetracycline (Tc) in benzyl alcohol. The activity of the extracted cobalt is then measured by means of a single-channel gamma-ray analyser coupled to a NaI (Tl) scintillation detector, the activity being proportional to the lead concentration, in a range from 2.5 to 150 μg. The interference of several elements (V, Th, Sc, Fe, La, Yb, Cu, Cd, Zn, Mn, Ni, Co, Al and Sn) was investigated by means of a previous separation between lead and these interfering elements. The analyses of artificial samples containing lead and the interfering elements gave a yield of 91.1 + - 3.2 %. The detection limit achieved by the method was 3.3 μg of lead. The radioreagent method was applied to lead analysis of samples from IAEA, namely: simulated air filter (Air-3), fresh water (W-3), dried animal blood (A-2) and calcinated animal bone (A-3/1). Lead was also determined in gasoline samples and air samples, these latter collected in the surroundings of the IPEN/CNEN/SP (Brazil). (Author) [pt

Camouflage, detection and identification of moving targets.

Science.gov (United States)

Hall, Joanna R; Cuthill, Innes C; Baddeley, Roland; Shohet, Adam J; Scott-Samuel, Nicholas E

2013-05-07

Nearly all research on camouflage has investigated its effectiveness for concealing stationary objects. However, animals have to move, and patterns that only work when the subject is static will heavily constrain behaviour. We investigated the effects of different camouflages on the three stages of predation-detection, identification and capture-in a computer-based task with humans. An initial experiment tested seven camouflage strategies on static stimuli. In line with previous literature, background-matching and disruptive patterns were found to be most successful. Experiment 2 showed that if stimuli move, an isolated moving object on a stationary background cannot avoid detection or capture regardless of the type of camouflage. Experiment 3 used an identification task and showed that while camouflage is unable to slow detection or capture, camouflaged targets are harder to identify than uncamouflaged targets when similar background objects are present. The specific details of the camouflage patterns have little impact on this effect. If one has to move, camouflage cannot impede detection; but if one is surrounded by similar targets (e.g. other animals in a herd, or moving background distractors), then camouflage can slow identification. Despite previous assumptions, motion does not entirely 'break' camouflage.

Varieties of Quest and the Religious Openness Hypothesis within Religious Fundamentalist and Biblical Foundationalist Ideological Surrounds

Directory of Open Access Journals (Sweden)

P. J. Watson

2013-12-01

Full Text Available According to the Religious Openness Hypothesis, the religious and psychological openness of American Christians is obscured by a defensive ghettoization of thought associated with a Religious Fundamentalist Ideological Surround and can be discovered instead within a Biblical Foundationalist Ideological Surround. A test of this claim examined Religious Fundamentalism, Biblical Foundationalism, Quest, and Multidimensional Quest Scales in 432 undergraduates. Christian Religious Reflection, Religious Schema, and Religious Orientation measures clarified these two ideological surrounds. Partial correlations controlling for Biblical Foundationalism described a Religious Fundamentalist Ideological Surround that more strongly rejected Quest and that more generally displayed a failure to integrate faith with intellect. Partial correlations controlling for Religious Fundamentalism revealed a Biblical Foundationalist Ideological Surround that was more open to Quest and that offered numerous demonstrations of an ability to unite faith with intellect. These data supplemented previous investigations in demonstrating that Christianity and other traditional religions have ideological resources for promoting a faithful intellect.

Parametric study of a target factory for laser fusion

International Nuclear Information System (INIS)

Sherohman, J.W.; Meier, W.R.

1980-01-01

An analysis of a target factory leading to the derivation of production rate equations has provided the basis for a parametric study. Rate equations describing the production of laser fusion targets have been developed for the purpose of identifying key parameters, attractive production techniques and cost scaling relationships for a commercial target factory

Orientation-specific surround suppression in the primary visual cortex varies as a function of autistic tendency

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Anastasia V Flevaris

2015-01-01

Full Text Available Individuals with autism spectrum disorder (ASD exhibit superior performance on tasks that rely on local details in an image, and they exhibit deficits in tasks that require integration of local elements into a unified whole. These perceptual abnormalities have been proposed to underlie many of the characteristic features of ASD, but the underlying neural mechanisms are poorly understood. Here, we investigated the degree to which orientation-specific surround suppression, a well-known form of contextual modulation in visual cortex, is associated with autistic tendency in neurotypical individuals. Surround suppression refers to the phenomenon that the response to a stimulus in the receptive field of a neuron is suppressed when it is surrounded by stimuli just outside the receptive field. The suppression is greatest when the center and surrounding stimuli share perceptual features such as orientation. Surround suppression underlies a number of fundamental perceptual processes that are known to be atypical in individuals with ASD, including perceptual grouping and perceptual pop-out. However, whether surround suppression in the primary visual cortex (V1 is related to autistic traits has not been directly tested before. We used fMRI to measure the neural response to a center Gabor when it was surrounded by Gabors having the same or orthogonal orientation, and calculated a suppression index (SI for each participant that denoted the magnitude of suppression in the same versus orthogonal conditions. SI was positively correlated with degree of autistic tendency in each individual, as measured by the Autism Quotient (AQ scale, a questionnaire designed to assess autistic traits in the general population. Age also correlated with SI and with autistic tendency in our sample, but did not account for the correlation between SI and autistic tendency. These results suggest a reduction in orientation-specific surround suppression in V1 with increasing autistic

Next to leading order semi-inclusive spin asymmetries

International Nuclear Information System (INIS)

Florian, D. de; Epele, L.N.; Fanchiotti, H.; Garcia C, C.A.; Sassot, R.

1996-04-01

We have computed semi-inclusive spin asymmetries for proton and deuteron targets including next to leading order (NLO) QCD corrections and contributions coming from the target fragmentation region. These corrections have been estimated using NLO fragmentation functions, parton distributions and also a model for spin dependent fracture functions which is proposed here. We have found that NLO corrections are small but non-negligible in a scheme where gluons are polarised and that our estimate for target fragmentation effects, which is in agreement with the available semi-inclusive data, does not modify significantly charged asymmetries but is non-negligible for the so called difference asymmetries. (author). 18 refs., 7 figs

Design and features of the target tracker of the Opera's target: study of the electron channel events

International Nuclear Information System (INIS)

Chon-Sen, N.

2009-01-01

Neutrino oscillations are now well acknowledged, the purpose of the Opera experiment is to show how ν τ appear in a ν μ beam. The ν μ beam is produced at CERN and crosses the earth crust on a distance of 732 km before being detected in the Gran-Sasso underground laboratory. The Opera experiment uses the technique of the photographic emulsion. The detector target is a series of walls of lead bricks, each brick being made of photographic emulsions intercalated with lead sheets. A target tracker enables the localization of the brick in which the neutrino interaction has happened. As soon as the brick is found, the brick is removed from the detector and the emulsion is developed and analysed. the target tracker is made up of plastic scintillator bars on which optic fibers are stuck to collect photons and send them to photomultipliers. The main purpose of this work is the calibration of the target tracker. The first chapter introduces the standard model, the neutrino and the neutrino oscillation phenomenon. The second chapter reviews the neutrino experiments worldwide. The third chapter describes the Opera experiment while chapter 4 and 5 are dedicated to the design and operation of the target tracker. The last chapter studies through simulation the behaviour of the target tracker when submitted to an electron beam in order to use it as a complementary tool for the identification of the τ → e channel. (A.C.)

Design of the MYRRHA Spallation Target Assembly

International Nuclear Information System (INIS)

Keijers, S.; Fernandez, R.; Stankovskiy, A.; Kennedy, G.; Van Tichelen, K.

2015-01-01

MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) is a multi-purpose research facility currently being developed at SCK.CEN. MYRRHA is based on the ADS (Accelerator Driven System) concept where a proton accelerator, a spallation target and a subcritical reactor are coupled. MYRRHA will demonstrate the ADS full concept by coupling these three components at a reasonable power level. As a flexible irradiation facility, the MYRRHA research reactor will be able to work in both critical and subcritical modes. In this way, MYRRHA will allow fuel developments for innovative reactor systems, material research for GEN IV and fusion reactors, and radioisotope production for medical and industrial applications. MYRRHA will be cooled by Lead Bismuth Eutectic (LBE) and will play an important role in the development of the Pb-alloys technology needed for the LFR (Lead Fast Reactor) GEN IV concept. This paper describes the evolution of the MYRRHA spallation target design. In the early phase of the MYRRHA project (XT-ADS), the target design was based on a dedicated spallation loop inside the primary reactor vessel. Within the core, the 3 central fuel assembly positions were occupied by the spallation target, which enabled a windowless design created by a free surface of LBE facing the proton beam. The windowless option was preferred because of high heat loads in combination with severe irradiation damage in the target region would result in unacceptably short lifetimes of a target window. The LBE in the loop served as spallation target and as target coolant, but was separated from the LBE cooling the reactor core. The loop was equipped with its own pump, heat exchanger and conditioning system. The change from cyclotron to linear accelerator allowed the increase in proton energy from 350 MeV to 600 MeV. This modification led to an important reduction of the specific heat load at the target level and an improvement of the neutronic performance. In addition to

Lead and chromium removal from leachate using horsetail (Equisetum hyemale

Directory of Open Access Journals (Sweden)

E. Kurniati

2014-01-01

Full Text Available Phytoremediation has been widely used for wastewater treatment technology. Horsetail was investigated for its capacity to remediate lead and chromium in leachate. This plant seemed to be an effective choice for phytoremediation due to its survival in extreme to moderate conditions, the availability of annual or perennial varieties and a deep root system. Conducted in a greenhouse, this research used leachate from final disposal. The leachate was exposed to six treated plants with three multiplications using activated natural zeolite media for one month. The treatments were flow system i.e. batch and continue, and living plants weight that is 0, 153 and 306 g planted in 20 cm diameter and 30 cm deep pots. The leachate pH, temperature, lead, and chromium concentration were observed and also the surrounding temperature and humidity. Results showed that 82.2% of lead can be removed by 153 gram horsetail on batch system as well as 61.2% chromium removal by 153 gram horsetail on continue system. Horsetail seemed to have future to be applied in phytoremediation of artisanal and small scale mining waste.

Vertex detector working as an active target in multihadron production on nuclei

Energy Technology Data Exchange (ETDEWEB)

Albini, E [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Brescia Univ. (Italy). Ist. di Matematica); Artuso, M; Bacchiocchi, G; D' Angelo, P; Moroni, L; Ragusa, F; Rancoita, P G; Sala, S [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Bellini, G

1980-12-01

In this paper a vertex detector working as active target is described. It consists of a telescope of nuclear targets surrounded by two coaxial cylindrical MWPCs, working in the proportional regime. The energy loss in the two 6 mm gaps of the chambers is measured with an accuracy better than 18%. The coordinates of the track along the sense wires are measured using the charge division method with an accuracy of 0.5-1.0%. The efficiency is about 99.5%. This device is used in an experiment concerned with multihadron production on nuclei, coupled with a forward spectrometer in order to detect and recognize grey, black and shower secondary particles.

Peeling lead paint turns into poisonous dust. Guess where it ends up? A media campaign to prevent childhood lead poisoning in New York City.

Science.gov (United States)

Greene, Danielle; Tehranifar, Parisa; DeMartini, Diana P; Faciano, Andrew; Nagin, Deborah

2015-06-01

Successful public health media campaigns promote messages, increase awareness, engage the public, and encourage behavior change. Between 2004 and 2006, the Lead Poisoning Prevention Program of the New York City Department of Health and Mental Hygiene conducted a media campaign grounded in social learning theory and the social marketing model to increase parents' awareness of childhood lead poisoning, ways to protect their children, and property owners' legal responsibility to fix peeling lead paint safely, and increase awareness of regulatory changes and encourage enforcement of New York City's Local Law 1 of 2004. Campaign materials were focus group tested and the campaign was refined annually. The campaign ran city-wide and in targeted high-risk neighborhoods. Neighborhoods and media venue (bus, train, kiosk, and store) changed annually, based on population risk factors and venue availability. Exposure to the campaign, campaign-related knowledge, and behavior were assessed using pre- and postcampaign street intercept surveys. Results showed that campaign reached the targeted population, and had an impact on knowledge of lead poisoning prevention measures as evidenced by increased knowledge of lead paint exposures sources in one year and increased knowledge of preventive behaviors in another year; these improvements were observed for both genders and most ethnic, primary language, educational attainment, and age groups in each year. Lessons learned indicate that well-targeted media campaigns, designed with audience participation, can reach parents through various venues, and improve key knowledge areas. Evaluation challenges faced include high levels of knowledge at baseline, competing media messages, and balancing between program needs and evaluation design. © 2015 Society for Public Health Education.

Opportunity's Surroundings on Sol 1798 (Polar)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a polar projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

Opportunity's Surroundings on Sol 1798 (Vertical)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a vertical projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

Opportunity's Surroundings on Sol 1687 (Vertical)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a vertical projection with geometric seam correction.

Opportunity's Surroundings on Sol 1687 (Polar)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a polar projection with geometric seam correction.

Investigation of ultrashort pulse laser ablation of solid targets by measuring the ablation-generated momentum using a torsion pendulum.

Science.gov (United States)

Zhang, Nan; Wang, Wentao; Zhu, Xiaonong; Liu, Jiansheng; Xu, Kuanhong; Huang, Peng; Zhao, Jiefeng; Li, Ruxin; Wang, Mingwei

2011-04-25

50 fs - 12 ps laser pulses are employed to ablate aluminum, copper, iron, and graphite targets. The ablation-generated momentum is measured with a torsion pendulum. Corresponding time-resolved shadowgraphic measurements show that the ablation process at the optimal laser fluence achieving the maximal momentum is primarily dominated by the photomechanical mechanism. When laser pulses with specific laser fluence are used and the pulse duration is tuned from 50 fs to 12 ps, the generated momentum firstly increases and then remains almost constant, which could be attributed to the change of the ablation mechanism involved from atomization to phase explosion. The investigation of the ablation-generated momentum also reveals a nonlinear momentum-energy conversion scaling law, namely, as the pulse energy increases, the momentum obtained by the target increases nonlinearly. This may be caused by the effective reduction of the dissipated energy into the surrounding of the ablation zone as the pulse energy increases, which indicates that for femtosecond laser the dissipated energy into the surrounding target is still significant.

EGF-R is Expressed and AP-1 and NF-κ:B Are Activated in Stromal Myofibroblasts Surrounding Colon Adenocarcinomas Paralleling Expression of COX-2 and VEGF

Directory of Open Access Journals (Sweden)

Panagiotis A. Konstantinopoulos

2007-01-01

Full Text Available Background: COX-2 and VEGF are important triggers of colon cancer growth, metastasis and angiogenesis. Cox-2 promoter contains transcriptional regulatory elements for AP-1 and NF-κ:B transcription factors whilst vegf is a known AP-1 downstream target gene. We investigated whether stromal myofibroblasts surrounding colon adenocarcinomas express COX-2 and VEGF and whether activation of AP-1 and NF-κ:B, as well as expression of EGF-R parallel expression of COX-2 and VEGF in these cells. Methods: Immunohistochemical methodology was performed on archival sections from 40 patients with colon adenocarcinomas. We evaluated c-FOS, p-c-JUN (phosphorylated c-JUN, p-Iκ:B-α (phosphorylated Iκ:B-α, EGF-R, COX-2, NF-κ:B and VEGF expression in stromal myofibroblasts surrounding colon adenocarcinomas. Double immunostaining with a-smooth muscle actin and each antibody was done to verify the expression of these molecules in stromal myofibroblasts. Results: VEGF, p-Iκ:B-α, NF-κ:B, c-FOS, p-c-JUN, EGF-R and COX-2 were expressed in stromal myofibroblasts surrounding colon adenocarcinomas in the majority of cases. EGF-R, p-Iκ:B-α, NF-κ:B, c-FOS and p-c-JUN correlated positively with COX-2 and VEGF expression. Conclusion: Stromal myofibroblasts surrounding colon adenocarcinomas are an important source of VEGF and COX-2 production, while AP-1 and NF-κ:B transcription factors are activated and EGF-R is expressed in these cells and associated with COX-2 and VEGF production.

Tomography images of the Alpine roots and surrounding upper mantle

Science.gov (United States)

Plomerova, Jaroslava; Babuska, Vladislav

2017-04-01

Teleseismic body-wave tomography represents powerful tool to study regional velocity structure of the upper mantle and to image velocity anomalies, such as subducted lithosphere plates in collisional zones. In this contribution, we recapitulate 3D models of the upper mantle beneath the Alps, which developed at a collision zone of the Eurasian and African plates. Seismic tomography studies indicate a leading role of the rigid mantle lithosphere that functioned as a major stress guide during the plate collisions. Interactions of the European lithosphere with several micro-plates in the south resulted in an arcuate shape of this mountain range on the surface and in a complicated geometry of the Alpine subductions in the mantle. Early models with one bended lithosphere root have been replaced with more advanced models showing two separate lithosphere roots beneath the Western and Eastern Alps (Babuska et al., Tectonophysics 1990; Lippitsch et al., JGR 2003). The standard isotropic velocity tomography, based on pre-AlpArray data (the currently performed passive seismic experiment in the Alps and surroundings) images the south-eastward dipping curved slab of the Eurasian lithosphere in the Western Alps. On the contrary, beneath the Eastern Alps the results indicate a very steep northward dipping root that resulted from the collision of the European plate with the Adriatic microplate. Dando et al. (2011) interpret high-velocity heterogeneities at the bottom of their regional tomographic model as a graveyard of old subducted lithospheres. High density of stations, large amount of rays and dense ray-coverage of the volume studied are not the only essential pre-requisites for reliable tomography results. A compromise between the amount of pre-processed data and the high-quality of the tomography input (travel-time residuals) is of the high importance as well. For the first time, the existence of two separate roots beneath the Alps has been revealed from carefully pre

Lead generation and examples opinion regarding how to follow up hits.

Science.gov (United States)

Orita, Masaya; Ohno, Kazuki; Warizaya, Masaichi; Amano, Yasushi; Niimi, Tatsuya

2011-01-01

In fragment-based drug discovery (FBDD), not only identifying the starting fragment hit to be developed but also generating a drug lead from that starting fragment hit is important. Converting fragment hits to leads is generally similar to a high-throughput screening (HTS) hits-to-leads approach in that properties associated with activity for a target protein, such as selectivity against other targets and absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox), and physicochemical properties should be taken into account. However, enhancing the potency of the fragment hit is a key requirement in FBDD, unlike HTS, because initial fragment hits are generally weak. This enhancement is presently achieved by adding additional chemical groups which bind to additional parts of the target protein or by joining or combining two or more hit fragments; however, strategies for effecting greater improvements in effective activity are needed. X-ray analysis is a key technology attractive for converting fragments to drug leads. This method makes it clear whether a fragment hit can act as an anchor and provides insight regarding introduction of functional groups to improve fragment activity. Data on follow-up chemical synthesis of fragment hits has allowed for the differentiation of four different strategies: fragment optimization, fragment linking, fragment self-assembly, and fragment evolution. Here, we discuss our opinion regarding how to follow up on fragment hits, with a focus on the importance of fragment hits as an anchor moiety to so-called hot spots in the target protein using crystallographic data. Copyright © 2011 Elsevier Inc. All rights reserved.

About miRNAs, miRNA seeds, target genes and target pathways.

Science.gov (United States)

Kehl, Tim; Backes, Christina; Kern, Fabian; Fehlmann, Tobias; Ludwig, Nicole; Meese, Eckart; Lenhof, Hans-Peter; Keller, Andreas

2017-12-05

miRNAs are typically repressing gene expression by binding to the 3' UTR, leading to degradation of the mRNA. This process is dominated by the eight-base seed region of the miRNA. Further, miRNAs are known not only to target genes but also to target significant parts of pathways. A logical line of thoughts is: miRNAs with similar (seed) sequence target similar sets of genes and thus similar sets of pathways. By calculating similarity scores for all 3.25 million pairs of 2,550 human miRNAs, we found that this pattern frequently holds, while we also observed exceptions. Respective results were obtained for both, predicted target genes as well as experimentally validated targets. We note that miRNAs target gene set similarity follows a bimodal distribution, pointing at a set of 282 miRNAs that seems to target genes with very high specificity. Further, we discuss miRNAs with different (seed) sequences that nonetheless regulate similar gene sets or pathways. Most intriguingly, we found miRNA pairs that regulate different gene sets but similar pathways such as miR-6886-5p and miR-3529-5p. These are jointly targeting different parts of the MAPK signaling cascade. The main goal of this study is to provide a general overview on the results, to highlight a selection of relevant results on miRNAs, miRNA seeds, target genes and target pathways and to raise awareness for artifacts in respective comparisons. The full set of information that allows to infer detailed results on each miRNA has been included in miRPathDB, the miRNA target pathway database (https://mpd.bioinf.uni-sb.de).

INTERACTIONS OF THE INFRARED BUBBLE N4 WITH ITS SURROUNDINGS

Energy Technology Data Exchange (ETDEWEB)

Liu, Hong-Li; Li, Jin-Zeng; Yuan, Jing-Hua; Huang, Maohai; Huang, Ya-Fang; Zhang, Si-Ju [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Wu, Yuefang [Department of Astronomy, Peking University, 100871 Beijing (China); Liu, Tie [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Dubner, G.; Paron, S.; Ortega, M. E. [1Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Molinari, Sergio [Istituto di Astrofisica e Planetologia Spaziali—IAPS, Istituto Nazionale di Astrofisica—INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Zavagno, Annie; Samal, Manash R., E-mail: hlliu@nao.cas.cn [Aix Marseille Universit, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

2016-02-10

The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H ii regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the H ii region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 × 10{sup 22} cm{sup −2}, mean volume density of about 4.4 × 10{sup 4} cm{sup −3}, and a mean mass of 320 M{sub ⊙}. In addition, from PAH emission seen at 8 μm, free–free emission detected at 20 cm, and a probability density function in special regions, we could identify clear signatures of the influence of the H ii region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.

Development of new target concepts for proton beams at CERN/ISOLDE

CERN Document Server

Delonca, Melanie; Montavon, Ghislain; Peyraut, Francois

More and more, the power of primary beam sent onto targets increases until reaching several kiloWatts of magnitude, inducing new problematic and challenges. Consequently, the need of new target design arises and leads to new conceptual design proposal. Amongst them, a concept of Lead Bismuth Eutectic (LBE) loop target making use of an heat exchanger (HEX) and a pump has been proposed during the European project EURISOL Design Study. This concept proposed an improvement in terms of release efficiency of short-lived species by transforming the irradiated liquid into droplets shape. This thesis presents the development of this target design proposal. A prototype target has been developed and will be tested under proton beam at ISOLDE at Cern, Geneva. Several analytical tools for the study of this kind of targets are proposed, taking into account different design parameters. These tools can be applied for other high power target concept and allow an easy dimensioning of this kind of targets. As well, an innovativ...

Mechanical Characteristics Analysis of Surrounding Rock on Anchor Bar Reinforcement

Science.gov (United States)

Gu, Shuan-cheng; Zhou, Pan; Huang, Rong-bin

2018-03-01

Through the homogenization method, the composite of rock and anchor bar is considered as the equivalent material of continuous, homogeneous, isotropic and strength parameter enhancement, which is defined as reinforcement body. On the basis of elasticity, the composite and the reinforcement are analyzed, Based on strengthening theory of surrounding rock and displacement equivalent conditions, the expression of reinforcement body strength parameters and mechanical parameters is deduced. The example calculation shows that the theoretical results are close to the results of the Jia-mei Gao[9], however, closer to the results of FLAC3D numerical simulation, it is proved that the model and surrounding rock reinforcement body theory are reasonable. the model is easy to analyze and calculate, provides a new way for determining reasonable bolt support parameters, can also provides reference for the stability analysis of underground cavern bolting support.

Trajectories and Maneuvers of Surrounding Vehicles with Panoramic Camera Arrays

DEFF Research Database (Denmark)

Dueholm, Jacob Velling; Kristoffersen, Miklas Strøm; Satzoda, Ravi K.

2016-01-01

Vision-based research for intelligent vehicles have traditionally focused on specific regions around a vehicle, such as a front looking camera for, e.g., lane estimation. Traffic scenes are complex and vital information could be lost in unobserved regions. This paper proposes a framework that uses...... four visual sensors for a full surround view of a vehicle in order to achieve an understanding of surrounding vehicle behaviors. The framework will assist the analysis of naturalistic driving studies by automating the task of data reduction of the observed trajectories. To this end, trajectories...... are estimated using a vehicle detector together with a multiperspective optimized tracker in each view. The trajectories are transformed to a common ground plane, where they are associated between perspectives and analyzed to reveal tendencies around the ego-vehicle. The system is tested on sequences from 2.5 h...

Conceptual design studies for the liquid metal target META:LIC

International Nuclear Information System (INIS)

Class, A.G.; Fazio, C.; Fetzer, J.R.; Gordeev, S.

2014-01-01

When the construction of ESS (European Spallation Source) in Sweden was initiated, the target station concept selection group decided to reevaluate a variety of target designs to respect new developments in their selection process. The META:LIC (MEgawatt TArget:Lead bIsmuth Cooled) target concept was developed following an extensive analysis of existing and new proposed designs and reached the level of proof of principle within only 2 years. ESS selected META:LIC as comparative target option for licensing purposes during the design update phase of ESS. The present work describes the design motivation of META:LIC referring to properties and design features of other targets. Therefore, META:LIC design is an evolutionary target which incorporates the extensive experience of liquid metal targets. The modular LBE (Lead Bismuth Eutectic) target concept with focus on the target module is introduced. Both, a window target option for the start of operation and a windowless option with extended lifetime are foreseen. Thermohydraulic simulations show that adequate window cooling can be realized. The stability of the free surface in the windowless option has been shown. Robust target module instrumentation based on free surface levels and the MEGAPIE experience is proposed for target control. Since the META:LIC concept foresees a horizontal extraction for both moderators and target from the monolith a safety concept based on the SNS and JSNS experience is proposed

Reversible air-induced optical and electrical modulation of methylammonium lead bromide (MAPbBr3) single crystals

Science.gov (United States)

Zhang, Huotian; Liu, Yiting; Lu, Haizhou; Deng, Wan; Yang, Kang; Deng, Zunyi; Zhang, Xingmin; Yuan, Sijian; Wang, Jiao; Niu, Jiaxin; Zhang, Xiaolei; Jin, Qingyuan; Feng, Hongjian; Zhan, Yiqiang; Zheng, Lirong

2017-09-01

The photoluminescence (PL) variations of organic-inorganic hybrid lead halide perovskites in different atmospheres are well documented, while the fundamental mechanism still lacks comprehensive understandings. This study reports the reversible optical and electrical properties of methylammonium lead bromide (MAPbBr3 or CH3NH3PbBr3) single crystals caused by air infiltration. With the change in the surrounding atmosphere from air to vacuum, the PL intensity of perovskite single crystals decreases, while the conductivity increases. By means of first-principles computational studies, the shallow trap states are considered as key elements in PL and conductivity changes. These results have important implications for the characterization and application of organic-inorganic hybrid lead halide perovskites in vacuum.

More target features in visual working memory leads to poorer search guidance: evidence from contralateral delay activity.

Science.gov (United States)

Schmidt, Joseph; MacNamara, Annmarie; Proudfit, Greg Hajcak; Zelinsky, Gregory J

2014-03-05

The visual-search literature has assumed that the top-down target representation used to guide search resides in visual working memory (VWM). We directly tested this assumption using contralateral delay activity (CDA) to estimate the VWM load imposed by the target representation. In Experiment 1, observers previewed four photorealistic objects and were cued to remember the two objects appearing to the left or right of central fixation; Experiment 2 was identical except that observers previewed two photorealistic objects and were cued to remember one. CDA was measured during a delay following preview offset but before onset of a four-object search array. One of the targets was always present, and observers were asked to make an eye movement to it and press a button. We found lower magnitude CDA on trials when the initial search saccade was directed to the target (strong guidance) compared to when it was not (weak guidance). This difference also tended to be larger shortly before search-display onset and was largely unaffected by VWM item-capacity limits or number of previews. Moreover, the difference between mean strong- and weak-guidance CDA was proportional to the increase in search time between mean strong-and weak-guidance trials (as measured by time-to-target and reaction-time difference scores). Contrary to most search models, our data suggest that trials resulting in the maintenance of more target features results in poor search guidance to a target. We interpret these counterintuitive findings as evidence for strong search guidance using a small set of highly discriminative target features that remain after pruning from a larger set of features, with the load imposed on VWM varying with this feature-consolidation process.

Seismic Tomography of the Arabian-Eurasian Collision Zone and Surrounding Areas

National Research Council Canada - National Science Library

Toksoz, M. N; Van der Hilst, Robert D; Sun, Youshun; Gulen, Levent; Kalafat, Dogan; Kuleli, Huseyin S; Li, Chang; Zhang, Haijiang

2008-01-01

... and surrounding areas, including Iran, Arabia, Eastern Turkey, and the Caucasus. The Arabian-Eurasian plate boundary is a complex tectonic zone shaped by continent-continent collision processes...

Two (or three) is one too many: testing the flexibility of contextual cueing with multiple target locations.

Science.gov (United States)

Zellin, Martina; Conci, Markus; von Mühlenen, Adrian; Müller, Hermann J

2011-10-01

Visual search for a target object is facilitated when the object is repeatedly presented within an invariant context of surrounding items ("contextual cueing"; Chun & Jiang, Cognitive Psychology, 36, 28-71, 1998). The present study investigated whether such invariant contexts can cue more than one target location. In a series of three experiments, we showed that contextual cueing is significantly reduced when invariant contexts are paired with two rather than one possible target location, whereas no contextual cueing occurs with three distinct target locations. Closer data inspection revealed that one "dominant" target always exhibited substantially more contextual cueing than did the other, "minor" target(s), which caused negative contextual-cueing effects. However, minor targets could benefit from the invariant context when they were spatially close to the dominant target. In sum, our experiments suggest that contextual cueing can guide visual attention to a spatially limited region of the display, only enhancing the detection of targets presented inside that region.

Blooming Trees: Substructures and Surrounding Groups of Galaxy Clusters

Science.gov (United States)

Yu, Heng; Diaferio, Antonaldo; Serra, Ana Laura; Baldi, Marco

2018-06-01

We develop the Blooming Tree Algorithm, a new technique that uses spectroscopic redshift data alone to identify the substructures and the surrounding groups of galaxy clusters, along with their member galaxies. Based on the estimated binding energy of galaxy pairs, the algorithm builds a binary tree that hierarchically arranges all of the galaxies in the field of view. The algorithm searches for buds, corresponding to gravitational potential minima on the binary tree branches; for each bud, the algorithm combines the number of galaxies, their velocity dispersion, and their average pairwise distance into a parameter that discriminates between the buds that do not correspond to any substructure or group, and thus eventually die, and the buds that correspond to substructures and groups, and thus bloom into the identified structures. We test our new algorithm with a sample of 300 mock redshift surveys of clusters in different dynamical states; the clusters are extracted from a large cosmological N-body simulation of a ΛCDM model. We limit our analysis to substructures and surrounding groups identified in the simulation with mass larger than 1013 h ‑1 M ⊙. With mock redshift surveys with 200 galaxies within 6 h ‑1 Mpc from the cluster center, the technique recovers 80% of the real substructures and 60% of the surrounding groups; in 57% of the identified structures, at least 60% of the member galaxies of the substructures and groups belong to the same real structure. These results improve by roughly a factor of two the performance of the best substructure identification algorithm currently available, the σ plateau algorithm, and suggest that our Blooming Tree Algorithm can be an invaluable tool for detecting substructures of galaxy clusters and investigating their complex dynamics.

Airborne lead and particulate levels in Semarang, Indonesia and potential health impacts.

Science.gov (United States)

Browne, D R; Husni, A; Risk, M J

1999-03-09

Spatial and temporal variation in airborne lead and total suspended particulates was examined in the city of Semarang, Indonesia, and surrounding area. Both airborne lead and TSP varied significantly with the type of urban development. Mean urban airborne lead levels were 0.35 microgram/m3 in the highway zone, 0.95 microgram/m3 in the residential zone, and 0.99 microgram/m3 in the commercial zone. Airborne lead levels in the industrial zone were significantly higher than all other areas, with a mean of 8.41 micrograms/m3. Airborne lead concentrations of this magnitude have not been reported in Indonesia previously. Mean TSP levels ranged from 115.5 micrograms/m3 to 165.8 micrograms/m3 in urban areas. Increased levels of TSP were associated with areas adjacent to major transportation routes. On a seasonal basis, TSP levels were significantly lower during the rainy season, while mean airborne lead levels did not show a significant seasonal trend. Observed ambient pollution levels were translated into potential heath impacts based on previously established relationships. Increased levels of TSP pollution near major roads was estimated to result in a 1.6% increase in mortality for all causes of death and a 7.9% increase in mortality due to respiratory disease. Estimated child blood lead levels indicated possible lead toxicity among Semarang children.

Control of lead solubility in soil contaminated with lead shot: Effect of soil pH

International Nuclear Information System (INIS)

Rooney, Corinne P.; McLaren, Ronald G.; Condron, Leo M.

2007-01-01

An incubation experiment was carried out to assess the rate of oxidation of Pb shot and subsequent transfer of Pb to the soil under a range of soil pH conditions. Lead shot corrosion was rapid, so that soil solution and fine earth ( 3 (CO 3 ) 2 (OH) 2 ), developed in crusts surrounding individual Pb pellets. However, irrespective of pH, Pb 2+ activities in the soil solutions, modelled using WHAM 6, were much lower than would be the case if they were controlled by the solubility of the dominant Pb compounds present in the Pb shot crust material. In contrast, modelling of soil solid-solution phase distribution of Pb, again using WHAM 6, suggested that, at least during the 24 months of the study, soil solution Pb concentrations were more likely to be controlled by sorption of Pb by the soil solid phase. - Sorption processes control Pb 2+ ion activity in soils contaminated with Pb shot

Structure-based lead optimization to improve antiviral potency and ADMET properties of phenyl-1H-pyrrole-carboxamide entry inhibitors targeted to HIV-1 gp120.

Science.gov (United States)

Curreli, Francesca; Belov, Dmitry S; Kwon, Young Do; Ramesh, Ranjith; Furimsky, Anna M; O'Loughlin, Kathleen; Byrge, Patricia C; Iyer, Lalitha V; Mirsalis, Jon C; Kurkin, Alexander V; Altieri, Andrea; Debnath, Asim K

2018-05-12

We are continuing our concerted effort to optimize our first lead entry antagonist, NBD-11021, which targets the Phe43 cavity of the HIV-1 envelope glycoprotein gp120, to improve antiviral potency and ADMET properties. In this report, we present a structure-based approach that helped us to generate working hypotheses to modify further a recently reported advanced lead entry antagonist, NBD-14107, which showed significant improvement in antiviral potency when tested in a single-cycle assay against a large panel of Env-pseudotyped viruses. We report here the synthesis of twenty-nine new compounds and evaluation of their antiviral activity in a single-cycle and multi-cycle assay to derive a comprehensive structure-activity relationship (SAR). We have selected three inhibitors with the high selectivity index for testing against a large panel of 55 Env-pseudotyped viruses representing a diverse set of clinical isolates of different subtypes. The antiviral activity of one of these potent inhibitors, 55 (NBD-14189), against some clinical isolates was as low as 63 nM. We determined the sensitivity of CD4-binding site mutated-pseudoviruses to these inhibitors to confirm that they target HIV-1 gp120. Furthermore, we assessed their ADMET properties and compared them to the clinical candidate attachment inhibitor, BMS-626529. The ADMET data indicate that some of these new inhibitors have comparable ADMET properties to BMS-626529 and can be optimized further to potential clinical candidates. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Drug-Target Interactions: Prediction Methods and Applications.

Science.gov (United States)

Anusuya, Shanmugam; Kesherwani, Manish; Priya, K Vishnu; Vimala, Antonydhason; Shanmugam, Gnanendra; Velmurugan, Devadasan; Gromiha, M Michael

2018-01-01

Identifying the interactions between drugs and target proteins is a key step in drug discovery. This not only aids to understand the disease mechanism, but also helps to identify unexpected therapeutic activity or adverse side effects of drugs. Hence, drug-target interaction prediction becomes an essential tool in the field of drug repurposing. The availability of heterogeneous biological data on known drug-target interactions enabled many researchers to develop various computational methods to decipher unknown drug-target interactions. This review provides an overview on these computational methods for predicting drug-target interactions along with available webservers and databases for drug-target interactions. Further, the applicability of drug-target interactions in various diseases for identifying lead compounds has been outlined. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

Energy Technology Data Exchange (ETDEWEB)

Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

2012-05-20

The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

International Nuclear Information System (INIS)

Liu Tie; Wu Yuefang; Zhang Huawei; Qin Shengli

2012-01-01

The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10 3 cm –3 and kinematic temperature ∼20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

"Partners in Science": A Model Cooperative Program Introducing High School Teachers and Students to Leading-Edge Pharmaceutical Science

Science.gov (United States)

Woska, Joseph R., Jr.; Collins, Danielle M.; Canney, Brian J.; Arcario, Erin L.; Reilly, Patricia L.

2005-01-01

"Partners in Science" is a cooperative program between Boehringer Ingelheim Pharmaceuticals, Inc. and area high schools in the community surrounding our Connecticut campus. It is a two-phase program that introduces high school students and teachers to the world of drug discovery and leading-edge pharmaceutical research. Phase 1 involves…

2 T superconducting detector solenoid for the PANDA target spectrometer

Energy Technology Data Exchange (ETDEWEB)

Efremov, A.A.; Koshurnikov, E.K. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation); Lobanov, Y.Y. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation)], E-mail: lobanov@jinr.ru; Makarov, A.F. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation); Orth, H. [Gesellschaft fuer Schwerionenforschung, Planckstrasse 1, D-64291, Darmstadt (Germany); Sissakian, A.N.; Vodopianov, A.S. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation)

2008-02-01

This paper describes the JINR design of the large 2 T superconducting solenoid for the target spectrometer of the PANDA experiment at HESR (FAIR, GSI, Darmstadt, Germany). The solenoid coil has an inner radius of 1.08 m and a length of 2.90 m. This solenoid is non-centrally split providing a warm bore of 100 mm in diameter through the coil to accommodate sufficient space for the internal target installations. Maximally stored energy in the windings is 22.3 MJ. All tracking and calorimetric detectors surrounding the target point, with exception of a forward cone of 5{sup 0} opening, are placed inside the lqHe-cryostat. The main features of the design and technique are as follows: a copper stabilizer and soldering technique for the superconducting cable; a stainless steel cryostat; winding technique over a mandrel; coreless type of the coil; low operational current. The details of the PANDA solenoid design including the magnetic field and stress-strain calculations are covered.

Analytical Solution of Tunnel Surrounding Rock for Stress and Displacement Based on Lade–Duncan Criterion

Directory of Open Access Journals (Sweden)

MingZheng Zhu

2018-01-01

Full Text Available The deformation and failure of tunnel surrounding rock is the result of tunnel excavation disturbance and rock stress release. When the local stress of surrounding rock exceeds the elastic limit of rock mass, the plastic analysis of surrounding rock must be carried out to judge the stability of tunnel. In this study, the Lade–Duncan yield criterion is used to calculate the analytic solutions for the surrounding rock in a tunnel, and the radius and displacement of the plastic zone are deduced using an equilibrium equation. The plastic zone radius and displacement based on Lade–Duncan criterion and Mohr–Coulomb criterion were compared by using single-factor analysis method under the different internal friction angles, in situ stresses, and support resistances. The results show that the solutions of the radius and displacement of plastic zone calculated by the Lade–Duncan criterion are close to those of Mohr–Coulomb criterion under the high internal friction angle and support resistance or low in situ rock stress; however, the radius and displacement of the plastic zone calculated by the Lade–Duncan criterion are larger under normal circumstances, and the Lade–Duncan criterion is more applicable to the stability analysis of the surrounding rock in a tunnel.

The disintegration and vaporization of plastic targets irradiated by high-power laser pulses

International Nuclear Information System (INIS)

Greig, J.R.; Pechacek, R.E.

1977-01-01

We have studied the disintegration of polyethylene and polystyrene targets irradiated by 100-J 40-nsec Nd/glass laser pulses. At power densities of approximately-less-than10 12 W/cm 2 relatively massive targets (6 x 10 -5 to 5 x 10 -4 cm 3 ) are totally disintegrated to produce finely divided target material and un-ionized vapor. Both the size of the target and the presence or absence of a laser prepulse strongly influence the proportions of finely divided target material and un-ionized vapor, especially within the first few microseconds after peak laser power. This disintegration is always preceded by the emission of a hot fully ionized plasma, but only 1% of the target material is contained in the hot plasma. Typically, (1--3) x 10 19 atoms of un-ionized vapor are released as a slowly expanding (vapprox.10 5 cm/sec) cold dense gas cloud (n/sub o/>10 19 cm -3 ) surrounding the initial target position. This cloud of target material has subsequently been heated by absorption of a 300-J 100-nsec CO 2 laser pulse to produce an approximately fully ionized plasma

Pathologic anatomy of lead poisoning in dogs

Energy Technology Data Exchange (ETDEWEB)

Zook, B C

1972-01-01

Thirty-two dogs diagnosed as having lead poisoning were studied postmortem. Enlarged, pale staining nuclei of renal proximal tubular cells and hepatocytes were present in all affected dogs and they frequently contained acid-fast inclusions. Bone changes, consisting of persistent, thick cartilaginous trabeculae rimmed with bone, caused radiopaque bands in the metaphyses of eight immature dogs. Brain lesions were characterized by vascular damage. Distended arterioles and capillaries were lined with swollen or necrotic endothelium and were often surrounded by hemorrhage and edema. These changes were associated with laminar necrosis in the cerebral cortex. Proliferation of new capillaries and gliosis occurred in dogs with chronic encephalopathies. Other changes included hyperplasia of bone marrow, metarubricytes in blood vessels, necrosis of occasional striated muscle fibers, decreased numbers of sperm and ovarian follicles, and peripheral neuropathy.

Targeted nanoparticles for colorectal cancer

DEFF Research Database (Denmark)

Cisterna, Bruno A.; Kamaly, Nazila; Choi, Won Il

2016-01-01

Colorectal cancer (CRC) is highly prevalent worldwide, and despite notable progress in treatment still leads to significant morbidity and mortality. The use of nanoparticles as a drug delivery system has become one of the most promising strategies for cancer therapy. Targeted nanoparticles could...

Identifying housing that poisons: a critical step in eliminating childhood lead poisoning.

Science.gov (United States)

Reyes, Nimia L; Wong, Lee-Yang; MacRoy, Patrick M; Curtis, Gerald; Meyer, Pamela A; Evens, Anne; Brown, Mary Jean

2006-01-01

The purpose of our study was to develop a method to identify and prioritize "high-risk" buildings in Chicago that could be targeted for childhood lead poisoning prevention activities. We defined "high-risk" buildings as those where multiple children younger than 6 years with elevated blood lead levels (BLLs) had lived and where lead hazards were previously identified on environmental inspection. By linking 1997-2003 Chicago elevated blood lead surveillance, environmental inspection, and building footprint data, we found that 49,362 children younger than 6 years with elevated BLLs lived at 30,742 buildings. Of those, 67 were "high-risk" buildings and these were associated with 994 children with elevated BLLs. On average, 15 children with elevated BLLs had lived in each building (range: 10-53, median: 13). Almost two thirds (n = 43) of the high-risk buildings had two or more referrals for inspection to the same apartment or housing unit; of those, 40 percent (n = 17) failed to maintain lead-safe status after compliance. Linking blood lead surveillance, environmental inspection, and building footprint databases allowed us to identify individual high-risk buildings. This approach prioritizes lead hazard control efforts and may help health, housing, and environmental agencies in targeting limited resources to increase lead-safe housing for children.

Damaged Goods: Perception of Pornography Addiction as a Mediator Between Religiosity and Relationship Anxiety Surrounding Pornography Use.

Science.gov (United States)

Leonhardt, Nathan D; Willoughby, Brian J; Young-Petersen, Bonnie

2018-01-01

Recent research on pornography suggests that perception of addiction predicts negative outcomes above and beyond pornography use. Research has also suggested that religious individuals are more likely to perceive themselves to be addicted to pornography, regardless of how often they are actually using pornography. Using a sample of 686 unmarried adults, this study reconciles and expands on previous research by testing perceived addiction to pornography as a mediator between religiosity and relationship anxiety surrounding pornography. Results revealed that pornography use and religiosity were weakly associated with higher relationship anxiety surrounding pornography use, whereas perception of pornography addiction was highly associated with relationship anxiety surrounding pornography use. However, when perception of pornography addiction was inserted as a mediator in a structural equation model, pornography use had a small indirect effect on relationship anxiety surrounding pornography use, and perception of pornography addiction partially mediated the association between religiosity and relationship anxiety surrounding pornography use. By understanding how pornography use, religiosity, and perceived pornography addiction connect to relationship anxiety surrounding pornography use in the early relationship formation stages, we hope to improve the chances of couples successfully addressing the subject of pornography and mitigate difficulties in romantic relationships.

Tracking a convoy of multiple targets using acoustic sensor data

Science.gov (United States)

Damarla, T. R.

2003-08-01

In this paper we present an algorithm to track a convoy of several targets in a scene using acoustic sensor array data. The tracking algorithm is based on template of the direction of arrival (DOA) angles for the leading target. Often the first target is the closest target to the sensor array and hence the loudest with good signal to noise ratio. Several steps were used to generate a template of the DOA angle for the leading target, namely, (a) the angle at the present instant should be close to the angle at the previous instant and (b) the angle at the present instant should be within error bounds of the predicted value based on the previous values. Once the template of the DOA angles of the leading target is developed, it is used to predict the DOA angle tracks of the remaining targets. In order to generate the tracks for the remaining targets, a track is established if the angles correspond to the initial track values of the first target. Second the time delay between the first track and the remaining tracks are estimated at the highest correlation points between the first track and the remaining tracks. As the vehicles move at different speeds the tracks either compress or expand depending on whether a target is moving fast or slow compared to the first target. The expansion and compression ratios are estimated and used to estimate the predicted DOA angle values of the remaining targets. Based on these predicted DOA angles of the remaining targets the DOA angles obtained from the MVDR or Incoherent MUSIC will be appropriately assigned to proper tracks. Several other rules were developed to avoid mixing the tracks. The algorithm is tested on data collected at Aberdeen Proving Ground with a convoy of 3, 4 and 5 vehicles. Some of the vehicles are tracked and some are wheeled vehicles. The tracking algorithm results are found to be good. The results will be presented at the conference and in the paper.

Sputtering yield calculation for binary target

International Nuclear Information System (INIS)

Jimenez-Rodriguez, J.J.; Rodriguez-Vidal, M.; Valles-Abarca, J.A.

1979-01-01

The generalization for binary targets, of the ideas proposed by Sigmund for monoatomic targets, leads to a set of coupled intergrodifferential equations for the sputtering functions. After moment decomposition, the final formulae are obtained by the standard method based on the Laplace Transform, where the inverse transform is made with the aid of asymptotic expansions in the limit of very high projectile energy as compared to the surface binding energy. The possible loss of stoichiometry for binary targets is analyzed. Comparison of computed values of sputtering yield for normal incidence, with experimental results shows good agreement. (author)

Tumor-targeting peptides from combinatorial libraries*

Science.gov (United States)

Liu, Ruiwu; Li, Xiaocen; Xiao, Wenwu; Lam, Kit S.

2018-01-01

Cancer is one of the major and leading causes of death worldwide. Two of the greatest challenges infighting cancer are early detection and effective treatments with no or minimum side effects. Widespread use of targeted therapies and molecular imaging in clinics requires high affinity, tumor-specific agents as effective targeting vehicles to deliver therapeutics and imaging probes to the primary or metastatic tumor sites. Combinatorial libraries such as phage-display and one-bead one-compound (OBOC) peptide libraries are powerful approaches in discovering tumor-targeting peptides. This review gives an overview of different combinatorial library technologies that have been used for the discovery of tumor-targeting peptides. Examples of tumor-targeting peptides identified from each combinatorial library method will be discussed. Published tumor-targeting peptide ligands and their applications will also be summarized by the combinatorial library methods and their corresponding binding receptors. PMID:27210583

Structure and function of the interphotoreceptor matrix surrounding retinal photoreceptor cells.

Science.gov (United States)

Ishikawa, Makoto; Sawada, Yu; Yoshitomi, Takeshi

2015-04-01

The interphotoreceptor matrix (IPM) is a highly organized structure with interconnected domains surrounding cone and rod photoreceptor cells and extends throughout the subretinal space. Based on known roles of the extracellular matrix in other tissues, the IPM is thought to have several prominent functions including serving as a receptor for growth factors, regulating retinoid transport, participating in cytoskeletal organization in surrounding cells, and regulation of oxygen and nutrient transport. In addition, a number of studies suggest that the IPM also may play a significant role in the etiology of retinal degenerative disorders. In this review, we describe the present knowledge concerning the structure and function of the IPM under physiological and pathological conditions. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Target cells in internal dosimetry

Energy Technology Data Exchange (ETDEWEB)

Goessner, W

2003-07-01

Data related to radium induced bone sarcomas in humans are used as a model for defining target cells on bone surfaces and in the bone marrow. The differential distribution of radiation induced bone sarcoma types with a high ratio of non-bone producing, mainly fibroblastic tumours, challenges the ICRP concept that the bone lining cells are target cells. Multipotential mesenchymal stem cells are located within the range of alpha particles, and are the most likely target cells for the fibroblastic type of bone sarcoma. The histogenesis of bone sarcomas after irradiation with alpha emitters shows that their final histopathology is not dependent on a single target cell. Each target cell has a microenvironment, which has to be regarded as a synergistic morpho-functional tissue unit. For this the concept of 'histion', a term used in general pathology, is proposed. Interactions between target cells that have been hit by alpha-particles, leading to lethal, mutational or transformation events with all components of a 'histion', will prove critical to understanding the pathogenesis of both deterministic and stochastic late effects. (author)

Target cells in internal dosimetry

International Nuclear Information System (INIS)

Goessner, W.

2003-01-01

Data related to radium induced bone sarcomas in humans are used as a model for defining target cells on bone surfaces and in the bone marrow. The differential distribution of radiation induced bone sarcoma types with a high ratio of non-bone producing, mainly fibroblastic tumours, challenges the ICRP concept that the bone lining cells are target cells. Multipotential mesenchymal stem cells are located within the range of alpha particles, and are the most likely target cells for the fibroblastic type of bone sarcoma. The histogenesis of bone sarcomas after irradiation with alpha emitters shows that their final histopathology is not dependent on a single target cell. Each target cell has a microenvironment, which has to be regarded as a synergistic morpho-functional tissue unit. For this the concept of 'histion', a term used in general pathology, is proposed. Interactions between target cells that have been hit by alpha-particles, leading to lethal, mutational or transformation events with all components of a 'histion', will prove critical to understanding the pathogenesis of both deterministic and stochastic late effects. (author)

Grouping and crowding affect target appearance over different spatial scales.

Directory of Open Access Journals (Sweden)

Bilge Sayim

Full Text Available Crowding is the impairment of peripheral target perception by nearby flankers. A number of recent studies have shown that crowding shares many features with grouping. Here, we investigate whether effects of crowding and grouping on target perception are related by asking whether they operate over the same spatial scale. A target letter T had two sets of flanking Ts of varying orientations. The first set was presented close to the target, yielding strong crowding. The second set was either close enough to cause crowding on their own or too far to cause crowding on their own. The Ts of the second set had the same orientation that either matched the target's orientation (Grouped condition or not (Ungrouped condition. In Experiment 1, the Grouped flankers reduced crowding independently of their distance from the target, suggesting that grouping operated over larger distances than crowding. In Experiments 2 and 3 we found that grouping did not affect sensitivity but produced a strong bias to report that the grouped orientation was present at the target location whether or not it was. Finally, we investigated whether this bias was a response or perceptual bias, rejecting the former in favor of a perceptual grouping explanation. We suggest that the effect of grouping is to assimilate the target to the identity of surrounding flankers when they are all the same, and that this shape assimilation effect differs in its spatial scale from the integration effect of crowding.

The quest for targets executing MYC-dependent cell transformation

Directory of Open Access Journals (Sweden)

Markus eHartl

2016-06-01

Full Text Available MYC represents a transcription factor with oncogenic potential converting multiple cellular signals into a broad transcriptional response, thereby controlling the expression of numerous protein-coding and non-coding RNAs important for cell proliferation, metabolism, differentiation, and apoptosis. Constitutive activation of MYC leads to neoplastic cell transformation, and deregulated MYC alleles are frequently observed in many human cancer cell types. Multiple approaches have been performed to isolate genes differentially expressed in cells containing aberrantly activated MYC proteins leading to the identification of thousands of putative targets. Functional analyses of genes differentially expressed in MYC-transformed cells had revealed that so far more than forty upregulated or downregulated MYC targets are actively involved in cell transformation or tumorigenesis. However, for determination which of the known, or yet unidentified targets are responsible for processing the oncogenic MYC program, further systematic and selective approaches are required. The search for critical targets in MYC-dependent tumor cells is exacerbated by the fact that during tumor development, cancer cells progressively evolve in a multistep process thereby acquiring their characteristic features in an additive manner. Functional expression cloning, combinatorial gene expression and appropriate in vivo tests could represent adequate tools for dissecting the complex scenario of MYC-specified cell transformation. In this context, the central goal is to identify a minimal set of targets that suffices to phenocopy oncogenic MYC. Recently developed genomic editing tools could be employed to confirm the requirement of crucial transformation-associated targets.Knowledge about essential MYC regulated genes is beneficial to expedite the development of specific inhibitors to interfere with growth and viability of human tumor cells in which MYC is aberrantly activated

Volatile elements production rates in a 1.4 Gev proton-irradiated molten lead-bismuth target

CERN Document Server

Zanini, L; Everaerts, P; Fallot, M; Franberg, H; Gröschel, F; Jost, C; Kirchner, T; Kojima, Y; Köster, U; Lebenhaft, J; Manfrina, E; Pitcher, E J; Ravn, H L; Tall, Y; Wagner, W; Wohlmuther, M

2005-01-01

Production rates of volatile elements following spallation reaction of 1.4 GeV protons on a liquid Pb/Bi target have been measured. The experiment was performed at the ISOLDE facility at CERN. These data are of interest for the developments of targets for accelerator driven systems such as MEGAPIE. Additional data have been taken on a liquid Pb target. Calculations were performed using the FLUKA and MCNPX Monte Carlo codes coupled with the evolution codes ORIHET3 and FISPACT using different options for the intra-nuclear cascades and evaporation models. Preliminary results from the data analysis show good comparison with calculations for Hg and for noble gases. For other elements such as I it is apparent that only a fraction of the produced isotopes is released. The agreement with the experimental data varies depending on the model combination used. The best results are obtained using MCNPX with the INCL4/ABLA models and with FLUKA. Discrepancies are found for some isotopes produced by fission using the MCNPX ...

Vascular targeting with peptide libraries

Energy Technology Data Exchange (ETDEWEB)

Pasqualini, R. [La Jolla Cancer Research Center The Burnham Inst., La Jolla CA (United States)

1999-06-01

The authors have developed an 'in vivo' selection system in which phage capable of selective homing to different tissues are recovered from a phage display peptide library following intravenous administration. Using this strategy, they have isolate several organ and tumor-homing peptides. They have shown that each of those peptides binds of different receptors that are selectively expressed on the vasculature of the target tissue. The tumor-homing peptides bind to receptors that are up regulated in tumor angiogenic vasculature. Targeted delivery of doxorubicin to angiogenic vasculature using these peptides in animals models decrease toxicity and increased the therapeutic efficacy of the drug. Vascular targeting may facilitate the development of other treatment strategies that rely on inhibition of angio genesis and lead to advances to extend the potential for targeting of drugs, genes and radionuclides in the context of many diseases.

Binary mixtures of mercury/ selenium, and lead/selenium

African Journals Online (AJOL)

Physiologically-based biokinetic models have been developed for predicting simultaneously the Absorption, Distribution, Metabolism and Elimination (ADME) properties of lead (Pb) and selenium (Se), and mercury (Hg) and selenium in a number of target tissues of humans. This was done for three population groups, ...

Application of a controlled swirl in the XT-ADS spallation target

International Nuclear Information System (INIS)

Roelofs, F.; Siccama, N. B.; Jeanmart, H.; Tichelen, K. V.; Dierckx, M.; Schuurmans, P.

2008-01-01

Within the EUROTRANS project, a windowless spallation target is designed and assessed in which there is direct contact between the proton beamline vacuum from the accelerator and a lead-bismuth free surface flow. Windowless spallation targets, which are designed by SCK.CEN, based on their experience for the MYRRHA concept, are experimentally examined in a well instrumented water-loop at UCL. The design work and the experimental campaign are supported by numerical simulations which are performed at NRG. In the current paper, the application of a mild swirl in the windowless spallation target is assessed. For this purpose, SCK.CEN has designed and fabricate, a spallation target in which a controlled swirl is introduced in the annular feeder of the target nozzle. An experimental programme is performed at UCL in their water-loop to evaluate various swirl strengths in one specific target nozzle design. Prior to the experimental programme, numerical simulations were performed at NRG assessing the influence of various swirl strengths on the free surface behaviour. Experimental and numerical results show that a mild swirl stabilizes the free surface and also indicate that applying a stronger swirl leads to undesired free surface behaviour, ultimately leading to a strong vortex in the central downcomer. (authors)

Targets for the APEX experiment at ATLAS

International Nuclear Information System (INIS)

Greene, J.P.; Thomas, G.E.; Leonard, R.H.

1994-01-01

Targets of lead, tantalum, thorium and uranium have been produced for experiments with the APEX (Argonne Positron Experiment) apparatus at ATLAS (Argonne Tandem Linac Accelerator System). APEX is a device built at Argonne National Laboratory to investigate the anomalous positrons observed in collisions of very heavy ion beams on heavy targets. Both fixed and rotating targets have been used. The rotating target system involves a 4-quadrant wheel rotating at speeds up to 700 rpm with the position encoded into the data stream. In addition to the hundreds of targets produced for the heavy-ion reactions studied, a wide variety of targets were employed for beam diagnostics, detector calibration and target wheel development. The experiment used very heavy ion beams ( 238 U, 206 Pb and 208 Pb) from ATLAS and targets of 206 Pb, 208 Pb, 232 Th and 238 U produced in the laboratory

The meninges: new therapeutic targets for multiple sclerosis.

Science.gov (United States)

Russi, Abigail E; Brown, Melissa A

2015-02-01

The central nervous system (CNS) largely comprises nonregenerating cells, including neurons and myelin-producing oligodendrocytes, which are particularly vulnerable to immune cell-mediated damage. To protect the CNS, mechanisms exist that normally restrict the transit of peripheral immune cells into the brain and spinal cord, conferring an "immune-specialized" status. Thus, there has been a long-standing debate as to how these restrictions are overcome in several inflammatory diseases of the CNS, including multiple sclerosis (MS). In this review, we highlight the role of the meninges, tissues that surround and protect the CNS and enclose the cerebral spinal fluid, in promoting chronic inflammation that leads to neuronal damage. Although the meninges have traditionally been considered structures that provide physical protection for the brain and spinal cord, new data have established these tissues as sites of active immunity. It has been hypothesized that the meninges are important players in normal immunosurveillance of the CNS but also serve as initial sites of anti-myelin immune responses. The resulting robust meningeal inflammation elicits loss of localized blood-brain barrier (BBB) integrity and facilitates a large-scale influx of immune cells into the CNS parenchyma. We propose that targeting the cells and molecules mediating these inflammatory responses within the meninges offers promising therapies for MS that are free from the constraints imposed by the BBB. Importantly, such therapies may avoid the systemic immunosuppression often associated with the existing treatments. Copyright © 2015 Elsevier Inc. All rights reserved.

Automatic measurement of target crossing speed

Science.gov (United States)

Wardell, Mark; Lougheed, James H.

1992-11-01

The motion of ground vehicle targets after a ballistic round is launched can be a major source of inaccuracy for small (handheld) anti-armour weapon systems. A method of automatically measuring the crossing component to compensate the fire control solution has been devised and tested against various targets in a range of environments. A photodetector array aligned with the sight's horizontal reticle obtains scene features, which are digitized and processed to separate target from sight motion. Relative motion of the target against the background is briefly monitored to deduce angular crossing rate and a compensating lead angle is introduced into the aim point. Research to gather quantitative data and optimize algorithm performance is described, and some results from field testing are presented.

JAERI/KEK target material program overview

International Nuclear Information System (INIS)

Kikuchi, Kenji; Kogawa, Hiroyuki; Sasa, Toshinobu

2001-01-01

Mercury target was designed for megawatt neutron scattering facility in JAERI/KEK spallation neutron source. The incident proton energy and current are 3 GeV and 333 μA, respectively: the total proton energy is 1 MW in short pulses at a frequency of 25 Hz. Under the guide rule the mercury target was designed: the maximum temperature of target window is 170degC and induced stresses for the type 316 stainless steel are within limits of design guide. In order to demonstrate ADS (Accelerator Driven Systems) transmutation critical and engineering facilities have been designed conceptually. In engineering facility lead-bismuth spallation target station is to be planned. Objective to build the facility is to demonstrate material irradiation. According to neutronics calculation irradiation damage of the target vessel window will be 5 dpa per year. (author)

33 CFR 165.1411 - Security zone; waters surrounding U.S. Forces vessel SBX-1, HI.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security zone; waters surrounding U.S. Forces vessel SBX-1, HI. 165.1411 Section 165.1411 Navigation and Navigable Waters COAST GUARD... § 165.1411 Security zone; waters surrounding U.S. Forces vessel SBX-1, HI. (a) Location. The following...

The determination of levels of mercury, cadmium and lead in water samples from Naivasha area, Kenya

International Nuclear Information System (INIS)

Muigai, P.G.; Kamau, G.N.; Kinyua, A.M.

1995-01-01

The analysis of mercury, cadmium and lead in water samples from different environments (Lake Naivasha, River Malewa boreholes and Olkaria geothermal wells) in Naivasha region and their possible origins are reported. The levels of mercury and lead in the water samples were above the maximum permissible limits of 0.005 mg/1 and 0.1 mg/1 respectively, as stipulated by the WHO. On the other hand, 83.3% of the samples had cadmium levels above the maximum permissible limit of 0.01mg/1 in drinking water by WHO. The mercury and lead levels were also higher than those previously obtained from different regions of Kenya, while those for cadmium were within the corresponding range. Possible sources of elevated values were the geology of the surrounding area, sewage treatment works, use of phosphate rock fertilizers and lead fuels.(author)

Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

International Nuclear Information System (INIS)

Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki

2000-01-01

We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki [Nagasaki Univ. (Japan). School of Medicine

2000-07-01

We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

Neutron production from 40 GeV/c mixed proton/pion beam on copper, silver and lead targets in the angular range 30-135 degree

CERN Document Server

Agosteo, S; Dimovasili, E; Foglio-Para, A; Silari, M; Ulrici, L; Vincke, H

2005-01-01

The neutron emission from 50 mm thick copper, silver and lead targets bombarded by a mixed proton/pion beam with momentum of 40 GeV/c were measured at the CERN Super Proton Synchrotron. The neutron yield and spectral fluence per incident particle on target were measured with an extended range Bonner sphere spectrometer in the angular range 30-135 degree with respect to the beam direction. Monte Carlo simulations with the FLUKA code were performed to provide a priori information for the unfolding of the experimental data. The spectral fluences show two peaks, an isotropic evaporation component centred at 3 MeV and a high-energy peak sitting around 100-150 MeV. The experimental neutron yields are given in four energy bins: less than 100 keV, 0.1-20 MeV, 20-500 MeV and 0.5-2 GeV. The total yields show a systematic discrepancy of 30-50%, with a peak of 70% at the largest angles, with respect to the results of the Monte Carlo simulations, which it is believed to be mainly due to uncertainties in the beam normaliza...

Dosimetry of small electron fields shaped by lead

International Nuclear Information System (INIS)

Perez, M.; Hill, R.; Whitaker, M.; Greig, L.; West, M.; Jones, L.

2000-01-01

Full text: Electron fields can be used to treat superficial cancers. Field shaping can be achieved by placing lead on the patient surface to minimise the dose to surrounding areas and may improve beam penumbra compared to using standard applicators. However, significant dosimetry changes under high density material edges for electron fields have been reported (W Pohlit and KH Manegold, cited in The Physics of Radiation Therapy, P.M. Khan, 1994). This project evaluated the dosimetry of small dimension electron fields shaped with lead placed on the surface. Comparisons were made between circular lead cutouts (3 and 5cm diameters) and an open electron applicator (5cm diameter). For each of these fields depth doses and profiles were measured using a diode detector in a water phantom, and isodoses were measured using X-Omat film sandwiched within a Solid water phantom. Output factors were measured in the Solid water using a Markus parallel plate ionisation chamber. The effect of the lead thickness on the profiles and output was quantified and the thickness used for the final measurements selected so as to give less than 5% transmission of the primary dose. Penumbral widths for 6MeV and 8MeV using the lead cutouts showed distinct differences compared with the open applicator. At depths of the 90% relative dose the profiles for lead shaped fields showed tighter penumbra widths by an average of 2 mm. This became more pronounced nearer the surface where, at 2mm depth, the difference in penumbral widths was an average of 4mm. The 3cm lead cutouts showed surface dose increases of 6% and 9% for 6MeV and 8 MeV respectively. Depth dose parameters (D max and R 90 ) varied by no more than 2mm between the lead cutouts and the open applicator measurements. Lead can be used to shape electron fields for radiotherapy treatments. Depth dose characteristics do not vary significantly with a 5 cm circular applicator. The penumbral width indicates less isodose spread for the lead cutout

Arsenic and lead in foods: a potential threat to human health in Bangladesh.

Science.gov (United States)

Islam, Md Saiful; Ahmed, Md Kawser; Habibullah-Al-Mamun, Md; Islam, Kazi Nazrul; Ibrahim, Md; Masunaga, Shigeki

2014-01-01

The non-carcinogenic and carcinogenic risk of arsenic and lead to adults and children via daily dietary intake of food composites in Bangladesh was estimated. The target hazard quotients (THQs), hazard index (HI) and target carcinogenic risk (TR) were calculated to evaluate the non-carcinogenic and carcinogenic health risk from arsenic and lead. Most of the individual food composites contain a considerable amount of arsenic and lead. The highest mean concentrations of arsenic were found in cereals (0.254 mg kg⁻¹ fw) and vegetables (0.250 mg kg⁻¹ fw), and lead in vegetables (0.714 mg kg⁻¹ fw) and fish (0.326 mg kg⁻¹ fw). The results showed the highest THQs of arsenic in cereals and lead in vegetables for both adults and children which exceeded the safe limit (> 1) indicating that cereals and vegetables are the main food items contributing to the potential health risk. The estimated TR from ingesting dietary arsenic and lead from most of the foods exceeded 10⁻⁶, indicating carcinogenic risks for all adult people of the study area.

Diversity of vascular plants of Piestany and surroundings

International Nuclear Information System (INIS)

Penzesova, A.; Galusova, T.

2013-01-01

In the present work is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

Opportunity's Surroundings After Sol 1820 Drive

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). South is at the center; north at both ends. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

Lovelock black holes surrounded by quintessence

Science.gov (United States)

Ghosh, Sushant G.; Maharaj, Sunil D.; Baboolal, Dharmanand; Lee, Tae-Hun

2018-02-01

Lovelock gravity consisting of the dimensionally continued Euler densities is a natural generalization of general relativity to higher dimensions such that equations of motion are still second order, and the theory is free of ghosts. A scalar field with a positive potential that yields an accelerating universe has been termed quintessence. We present exact black hole solutions in D-dimensional Lovelock gravity surrounded by quintessence matter and also perform a detailed thermodynamical study. Further, we find that the mass, entropy and temperature of the black hole are corrected due to the quintessence background. In particular, we find that a phase transition occurs with a divergence of the heat capacity at the critical horizon radius, and that specific heat becomes positive for r_h

The dose distribution surrounding 192Ir and 137Cs seed sources

International Nuclear Information System (INIS)

Thomason, C.; Mackie, T.R.; Wisconsin Univ., Madison, WI; Lindstrom, M.J.; Higgins, P.D.

1991-01-01

Dose distributions in water were measured using LiF thermoluminescent dosemeters for 192 Ir seed sources with stainless steel and with platinum encapsulation to determine the effect of differing encapsulation. Dose distribution was measured for a 137 Cs seed source. In addition, dose distributions surrounding these sources were calculated using the EGS4 Monte Carlo code and were compared to measured data. The two methods are in good agreement for all three sources. Tables are given describing dose distribution surrounding each source as a function of distance and angle. Specific dose constants were also determined from results of Monte Carlo simulation. This work confirms the use of the EGS4 Monte Carlo code in modelling 192 Ir and 137 Cs seed sources to obtain brachytherapy dose distributions. (author)

Centrosome – a promising anti-cancer target

Directory of Open Access Journals (Sweden)

Rivera-Rivera Y

2016-12-01

Full Text Available Yainyrette Rivera-Rivera, Harold I Saavedra Department of Pharmacology, Ponce Health Sciences University-School of Medicine, Ponce Research Institute, Ponce, Puerto Rico Abstract: The centrosome, an organelle discovered >100 years ago, is the main microtubule-organizing center in mammalian organisms. The centrosome is composed of a pair of centrioles surrounded by the pericentriolar material (PMC and plays a major role in the regulation of cell cycle transitions (G1-S, G2-M, and metaphase-anaphase, ensuring the normality of cell division. Hundreds of proteins found in the centrosome exert a variety of roles, including microtubule dynamics, nucleation, and kinetochore–microtubule attachments that allow correct chromosome alignment and segregation. Errors in these processes lead to structural (shape, size, number, position, and composition, functional (abnormal microtubule nucleation and disorganized spindles, and numerical (centrosome amplification [CA] centrosome aberrations causing aneuploidy and genomic instability. Compelling data demonstrate that centrosomes are implicated in cancer, because there are important oncogenic and tumor suppressor proteins that are localized in this organelle and drive centrosome aberrations. Centrosome defects have been found in pre-neoplasias and tumors from breast, ovaries, prostate, head and neck, lung, liver, and bladder among many others. Several drugs/compounds against centrosomal proteins have shown promising results. Other drugs have higher toxicity with modest or no benefits, and there are more recently developed agents being tested in clinical trials. All of this emerging evidence suggests that targeting centrosome aberrations may be a future avenue for therapeutic intervention in cancer research. Keywords: centrosomes, cell cycle, mitosis, CA, CIN, cancer therapy

Demands for improvement in working surroundings for older workers in nuclear power plants

International Nuclear Information System (INIS)

Shizawa, Yasuhiro; Sakuda, Hiroshi; Ohashi, Tomoki

2003-01-01

Workers in three nuclear power plants belonging to Kansai Electric Power Co., Inc. were asked to complete a questionnaire. According to the accident reports, workers aged 50 or older had more accidents than those in 30s or 40s. Moreover, it is predicted that the average age of workers in Japan will increase during the first half of the 21st century. Therefore, investigations into working surroundings in which older workers can better perform their work would be useful. To this end, a questionnaire addressing issues related to working surroundings was conducted among workers in nuclear power plants and the demands for improvement of working surroundings for older workers are summarized. The demands of 'better lighting', 'making things less heavy', and installation of an elevator' were correlated with age, indicating that younger people have a tendency not to notice these issues. Thus, if the authority deciding on improvements in working surroundings is not an older worker, it is especially important that lighting, the weights of objects to be moved, and methods of moving between floors is taken into account. Findings specific to nuclear power plants were also reported. For example, employees who worked in the non-radiation controlled area demanded the installation of air conditioning and those who worked in the radiation controlled area demanded the establishment of a rest area. Further, we have developed a guidebook entitled 'a guidebook supporting workers' cooperation among all generations' to promote cooperation between older and younger workers. (author)

Performance of an electromagnetic calorimeter with lead-tungstate crystals

International Nuclear Information System (INIS)

Kohara, R.; Sugitate, T.; Sugita, N.; Tsuchimoto, Y.; Toyoda, D.; Homma, K.; Yamazaki, H.

2003-01-01

The performance of an electromagnetic calorimeter with lead-tungstate (PWO) crystals was tested by using 1 GeV photons. The calorimeter consisted of nine crystals of 20 x 20 x 200 mm in size arranged in a 3 x 3 array. The energy resolution was obtained to be σ E /E = (2.50 ± 0.75%) / √E + (1.25 ± 0.34%) with a photomultiplier tube (PMT) reading all signals. Another setup, reading the central cell with an avalanche photo diode (APD) and the surrounding 8 cells with the PMT, was also studied, however, its energy resolution was not scaled with the stochastic function and we found the resolution of about 10% around 1 GeV. (author)

Models and Approaches for Integrating Protected Areas with Their Surroundings: A Review of the Literature

Directory of Open Access Journals (Sweden)

Wenwu Du

2015-06-01

Full Text Available Several studies have identified threats that originate in areas surrounding protected areas (PAs. While there have been various efforts to integrate PAs with their surroundings, considerable challenges remain. Here we summarize these efforts to date, discuss their effectiveness, and provide recommendations for future research. Based on a broad literature review of theoretical and applied approaches, we have outlined 68 models for balancing conservation and sustainable development in PAs. We comprehensively analyzed 23 of these models for integrating PAs with their surroundings. They were divided into two categories: area-oriented and process-oriented approaches. This review reveals the absolute necessity of combining these two approaches for future conservation and sustainable development of PAs.

The analysis of creep characteristics of the surrounding rock of the carbonaceous rock tunnel based on Singh-Mitchell model

Science.gov (United States)

Luo, Junhui; Mi, Decai; Ye, Qiongyao; Deng, Shengqiang; Zeng, Fuquan; Zeng, Yongjun

2018-01-01

Carbonaceous rock has the characteristics of easy disintegration, softening, swelling and environmental sensitivity, which belongs to soft surrounding rock, and the deformation during excavation and long-term stability of the surrounding rock of carbonaceous rock tunnel are common problems in the construction of carbonaceous rock tunnel. According to the above, the Monitor and measure the displacement, temperature and osmotic pressure of the surrounding carbonaceous rock of the tunnel of Guangxi Hebai highway. Then it based on the obtaining data to study the creep mechanism of surrounding rock using Singh-Mitchell model and predict the deformation of surrounding rock before the tunnel is operation. The results show that the Singh-Mitchell creep model can effectively analyse and predict the deformation development law of surrounding rock of tunnel without considering temperature and osmotic pressure, it can provide reference for the construction of carbonaceous rock tunnel and the measures to prevent and reinforce it..

Chemical Investigations of ISOL target units for carbon and nitrogen beams

CERN Document Server

Franberg, H; Gäggeler, H W; Köster, U

2006-01-01

Radioactive Ion Beams (RIB) are of significant interest in a number of applications. ISOL (Isotope Separation On Line) facilities provide RIB with high beam intensities and good beam quality. An atom that is produced within the ISOL target will first diffuse out from the target material. During the effusion towards the transfer line and into the ion source the many contacts with the surrounding surfaces may cause unacceptable delays in the transport and, hence, losses of the shorter-lived isotopes. We performed systematic chemical investigations of adsorption in a temperature and concentration regime relevant for ISOL targets and ion source units, with regard to COx and NOx on Al2O3 and SiO2. These materials are potential construction materials for the above mentioned areas. Off-line and on-line tests have been performed using a gas thermo-chromatography set-up with radioactive tracers. The experiments were performed at the PROTRAC facility at Paul Scherrer Institute in Villigen, Switzerland.

Learning, Leading and Letting go of Control

DEFF Research Database (Denmark)

Jensen, Annie Aarup; Kjær-Rasmussen, Lone Krogh; Iversen, Ann-Merete

Learning, leading and letting go of control – Learner Led Approaches in Education Annie Aarup Jensen, Lone Krogh Kjær-Rasmussen, Ann-Merete Iversen and Anni Stavnskær Pedersen Abstract The aim of the paper is to introduce a new term in teaching in Higher Education: Learner Led Approaches...... in Education: LED. The sources of inspiration are many as are the experiences we draw from. Problem-based project work (PBL) being one, various classical teacher centered methods, and last but not least a variety of methods aiming towards developing creativity, innovational skills and entrepreneurship. LED...... is inspired by collaboration between professors from Aalborg University, Cornwall College and University College of Northern Denmark. Moravec (2008) claims that educational systems still operate in 1.0 or perhaps 2.0 mode while the surrounding cultures and societies operate in 3.0 mode. The amount...

Continuous and simultaneous measurement of the tank-treading motion of red blood cells and the surrounding flow using translational confocal micro-particle image velocimetry (micro-PIV) with sub-micron resolution

International Nuclear Information System (INIS)

Oishi, M; Utsubo, K; Kinoshita, H; Fujii, T; Oshima, M

2012-01-01

In this study, a translational confocal micro-particle image velocimetry (PIV) system is introduced to measure the microscopic interaction between red blood cells (RBCs) and the surrounding flow. Since the macroscopic behavior of RBCs, such as the tank-treading motion, is closely related to the axial migration and other flow characteristics in arterioles, the measurement method must answer the conflicting demands of sub-micron resolution, continuous measurement and applicability for high-speed flow. In order to avoid loss of the measurement target, i.e. RBCs, from the narrow field of view during high-magnification measurement, the translation stage with the flow device moves in the direction opposite the direction of flow. The proposed system achieves the measurement of higher absolute velocities compared with a conventional confocal micro-PIV system without the drawbacks derived from stage vibration. In addition, we have applied a multicolor separation unit, which can measure different phases simultaneously using different fluorescent particles, in order to clarify the interaction between RBCs and the surrounding flow. Based on our measurements, the tank-treading motion of RBCs depends on the shear stress gradient of the surrounding flow. Although, the relationship between the tank-treading frequency and the shear rate of the surrounding flow is of the same order as in the previous uniform shear rate experiments, our results reveal the remarkable behavior of the non-uniform membrane velocities and lateral velocity component of flow around the RBCs. (paper)

Impacts of emerging contaminants on surrounding aquatic environment from a youth festival.

Science.gov (United States)

Jiang, Jheng-Jie; Lee, Chon-Lin; Fang, Meng-Der; Tu, Bo-Wen; Liang, Yu-Jen

2015-01-20

The youth festival as we refer to Spring Scream, a large-scale pop music festival, is notorious for the problems of drug abuse and addiction. The origin, temporal magnitudes, potential risks and mass inputs of emerging contaminants (ECs) were investigated. Thirty targeted ECs were analyzed by solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry (SPE-LC-MS/MS). Sampling strategy was designed to characterize EC behavior in different stages (before and after the youth festival), based on multivariate data analysis to explore the contributions of contaminants from normal condition to the youth festival. Wastewater influents and effluents were collected during the youth festival (approximately 600 000 pop music fans and youth participated). Surrounding river waters are also sampled to illustrate the touristic impacts during peak season and off-season. Seasonal variations were observed, with the highest concentrations in April (Spring Scream) and the lowest in October (off-season). Acetaminophen, diclofenac, codeine, ampicillin, tetracycline, erythromycin-H2O, and gemfibrozil have significant pollution risk quotients (RQs > 1), indicating ecotoxicological concerns. Principal component analysis (PCA) and weekly patterns provide a perspective in assessing the touristic impacts and address the dramatic changes in visitor population and drug consumption. The highest mass loads discharged into the aquatic ecosystem corresponded to illicit drugs/controlled substances such as ketamine and MDMA, indicating the high consumption of ecstasy during Spring Scream.

Usefulness of virtual endoscopy for evaluating the relationship between the neck of intracranial aneurysm and surrounding vessels

International Nuclear Information System (INIS)

Ikeda, Jota; Horie, Hitoshi; Ishikura, Reiichi; Ando, Kumiko; Morikawa, Tsutomu; Tominaga, Satoru; Nakao, Norio

2000-01-01

Application of three-dimensional CT virtual endoscopy for evaluation of the neck and surrounding vessels of intracranial aneurysms. 3D-CT virtual endoscopy (VE) is a reconstructed image using computer processing of 3D-CT images. We evaluated the usefulness of a virtual endoscopy to analyze the relationship between the neck of an intracranial aneurysm and the surrounding vessels. Eight cases with intracranial aneurysms underwent digital subtraction angiography (DSA) and enhanced CT with transarterial infusion of contrast media. 3D-CT angiogram (3D-CTA) and virtual endoscopic images were obtained from the CT image data sets using surface rendering method. The relationship between the neck of an intracranial aneurysm and the surrounding vessels was confirmed by operation or IVR. VE clearly visualized the neck and surrounding vessels in all cases. Operation/IVR findings agreed with the virtual endoscopic findings in all cases, but not with the DSA or 3D-CTA findings in 4 and 2 cases, respectively. 3D-CTA and virtual endoscopy clearly visualizes the relationship between cerebral aneurysms and surrounding vessels, which is useful for determining IVR procedures. (author)

Delayed brain radiation necrosis: pathological review and new molecular targets for treatment.

Science.gov (United States)

Furuse, Motomasa; Nonoguchi, Naosuke; Kawabata, Shinji; Miyatake, Shin-Ichi; Kuroiwa, Toshihiko

2015-12-01

Delayed radiation necrosis is a well-known adverse event following radiotherapy for brain diseases and has been studied since the 1930s. The primary pathogenesis is thought to be the direct damage to endothelial and glial cells, particularly oligodendrocytes, which causes vascular hyalinization and demyelination. This primary pathology leads to tissue inflammation and ischemia, inducing various tissue protective responses including angiogenesis. Macrophages and lymphocytes then infiltrate the surrounding areas of necrosis, releasing inflammatory cytokines such as interleukin (IL)-1α, IL-6, and tumor necrosis factor (TNF)-α. Microglia also express these inflammatory cytokines. Reactive astrocytes play an important role in angiogenesis, expressing vascular endothelial growth factor (VEGF). Some chemokine networks, like the CXCL12/CXCR4 axis, are upregulated by tissue inflammation. Hypoxia may mediate the cell-cell interactions among reactive astrocytes, macrophages, and microglial cells around the necrotic core. Recently, bevacizumab, an anti-VEGF antibody, has demonstrated promising results as an alternative treatment for radiation necrosis. The importance of VEGF in the pathophysiology of brain radiation necrosis is being recognized. The discovery of new molecular targets could facilitate novel treatments for radiation necrosis. This literature review will focus on recent work characterizing delayed radiation necrosis in the brain.

One Japanese case on taxation surrounding foreign trust

OpenAIRE

SUZUKI, Yuya

2015-01-01

Taxation surrounding trust at cross-border situation is paid attention to byworldwide basis. Japan is not exception. According to recent Japanesejurisprudence, where a trust had been established in accordance with State law ofNew Jersey, the U.S., it was disputed whether or not the act settling that trust fellwithin “shintaku koui (an act of trust)” and one of the related members, who had beena minor child at that time, fell within “jyueki sha (beneficiary)” under JapaneseInheritance Tax Act....

Immersive Environments: Using Flow and Sound to Blur Inhabitant and Surroundings

Science.gov (United States)

Laverty, Luke

---in the form of a live-work vertical artist commune in New York City---the antithesis of intimate, human architectural environments---coupled with the design of a sound sensory experiential walk through the surrounding blurred neighborhood boundaries in the attempt to exploit and create an environment one becomes absorbed within and feels comfortable enough with which to experience flow. To do so, the characteristics of flow lead to the capturing of the senses, interaction, and flexibility. This thesis will explore and exploit how one perceives, interacts with, and becomes attached to when confronted with a space or artifact; reintroducing the humanity into contemporary architecture.

Leading local politicians visit CERN

CERN Multimedia

2001-01-01

Left to right:  Professor Maiani, Ernest Nycollin, Anne-Marie Comparini, and Jean Pépin surrounded by young PRAC. On the 13th of November leading local politicians : Mme Anne-Marie Comparini, Présidente du Conseil régional de Rhône-Alpes, M. Ernest Nycollin, Président du Conseil général de la Haute-Savoie et M. Jean Pépin, Président du Conseil général de l'Ain took part in a ceremony which featured the insertion of one of the first LHC magnets into its cryostat.  The department of l'Ain financed a large part of the contruction of building SMA 18 which will see intense activity during the assembly of LHC magnets over the next four years. The department of Haute-Savoie helped in the development of the ultrasonic welding machine for the superconducting cables and the conception of integrated circuits that will be used to measure temperature and pressure inside the magnets. T...

The bird species of pandam wildlife park and the surrounding ...

African Journals Online (AJOL)

The effect of time of day as well as vegetation variables on bird species diversity in the park and surrounding farmlands was also conducted. 10 transects in each study site were surveyed twice between during the dry season and vegetation variables (trees, fingers, finger-rings two- hand, grazing, farming, canopy cover, ...

Lovelock black holes surrounded by quintessence

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Sushant G. [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa); Centre for Theoretical Physics, Multidisciplinary Centre for Advanced Research and Studies (MCARS), New Delhi (India); Maharaj, Sunil D.; Baboolal, Dharmanand; Lee, Tae-Hun [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa)

2018-02-15

Lovelock gravity consisting of the dimensionally continued Euler densities is a natural generalization of general relativity to higher dimensions such that equations of motion are still second order, and the theory is free of ghosts. A scalar field with a positive potential that yields an accelerating universe has been termed quintessence. We present exact black hole solutions in D-dimensional Lovelock gravity surrounded by quintessence matter and also perform a detailed thermodynamical study. Further, we find that the mass, entropy and temperature of the black hole are corrected due to the quintessence background. In particular, we find that a phase transition occurs with a divergence of the heat capacity at the critical horizon radius, and that specific heat becomes positive for r{sub h} < r{sub c} allowing the black hole to become thermodynamically stable. (orig.)

Surrounding land cover types as predictors of palustrine wetland vegetation quality in conterminous USA

Science.gov (United States)

Stapanian, Martin A.; Gara, Brian; Schumacher, William

2018-01-01

The loss of wetland habitats and their often-unique biological communities is a major environmental concern. We examined vegetation data obtained from 380 wetlands sampled in a statistical survey of wetlands in the USA. Our goal was to identify which surrounding land cover types best predict two indices of vegetation quality in wetlands at the regional scale. We considered palustrine wetlands in four regions (Coastal Plains, North Central East, Interior Plains, and West) in which the dominant vegetation was emergent, forested, or scrub-shrub. For each wetland, we calculated weighted proportions of eight land cover types surrounding the area in which vegetation was assessed, in four zones radiating from the edge of the assessment area to 2 km. Using Akaike's Information Criterion, we determined the best 1-, 2- and 3-predictor models of the two indices, using the weighted proportions of the land cover types as potential predictors. Mean values of the two indices were generally higher in the North Central East and Coastal Plains than the other regions for forested and emergent wetlands. In nearly all cases, the best predictors of the indices were not the dominant surrounding land cover types. Overall, proportions of forest (positive effect) and agriculture (negative effect) surrounding the assessment area were the best predictors of the two indices. One or both of these variables were included as predictors in 65 of the 72 models supported by the data. Wetlands surrounding the assessment area had a positive effect on the indices, and ranked third (33%) among the predictors included in supported models. Development had a negative effect on the indices and was included in only 28% of supported models. These results can be used to develop regional management plans for wetlands, such as creating forest buffers around wetlands, or to conserve zones between wetlands to increase habitat connectivity.

Investigation of fusion gain in fast ignition with conical targets

Directory of Open Access Journals (Sweden)

MJ Tabatabaei

2011-03-01

Full Text Available Fast ignition is a new scheme for inertial confinement fusion (ICF. In this scheme, at first the interaction of ultraintense laser beam with the hohlraum wall surrounding a capsule containing deuterium-tritium (D-T fuel causes implosion and compression of fuel to high density and then laser produced protons penetrate in the compressed fuel and deposit their energy in it as the ignition hot spot is created. In this paper, following the energy gain of spherical target and considering relationship of the burn fraction to burn duration, we have obtained the energy gain of conical targets characterized by the angle β, and found a hemispherical capsule (β=π/2 has a gain as high as 96% of that of the whole spherical capsule. The results obtained in this study are qualitatively consistent with Atzeni et al.'s studies of simulations.

A comparison of fossilized dinosaur bone and the surrounding rock using PIXE analysis

International Nuclear Information System (INIS)

Neilsen, D.W.; Rees, L.B.; Mangelson, N.F.; Hill, M.W.

1992-01-01

Six samples of fossilized dinosaur bone and surrounding rock were analyzed by PIXE to investigate general relations between the bone and rock. The powdered samples were brought into an acid solution by a lithium metaborate fusion process. The data were analyzed with chemometric methods to successfully differentiate the bone samples from the complementary rock samples. The Sr/Ca ratio is consistently higher in fossilized bone than the surrounding rock. Ba, Y and U, when found in the rock, appear in significantly higher concentrations in the bone. S and Ti, elements commonly found in rock samples, are not found in the bone samples. (author)

Earthquakes in Switzerland and surrounding regions during 2007

Energy Technology Data Exchange (ETDEWEB)

Baer, M.; Deichmann, N.; Clinton, J.; Husen, S.; Faeh, D.; Giardini, D.; Kaestli, P.; Kradolfer, U.; Wiemer, S

2008-12-15

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2007. During this period, 531 earthquakes and 92 quarry blasts were detected and located in the region under consideration. Of these earthquakes, 30 are aftershocks of the stimulation of a proposed geothermal reservoir beneath the city of Basel in December of 2006. With 20 events with {mu}{sub {iota}} {>=} 2.5, four of which were artificially induced, the seismic activity in the year 2007 was far below the average over the previous 32 years. (author)

Earthquakes in Switzerland and surrounding regions during 2007

International Nuclear Information System (INIS)

Baer, M.; Deichmann, N.; Clinton, J.; Husen, S.; Faeh, D.; Giardini, D.; Kaestli, P.; Kradolfer, U.; Wiemer, S.

2008-01-01

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2007. During this period, 531 earthquakes and 92 quarry blasts were detected and located in the region under consideration. Of these earthquakes, 30 are aftershocks of the stimulation of a proposed geothermal reservoir beneath the city of Basel in December of 2006. With 20 events with Μ ι ≥ 2.5, four of which were artificially induced, the seismic activity in the year 2007 was far below the average over the previous 32 years. (author)

Impact of water drops on small targets

Science.gov (United States)

Rozhkov, A.; Prunet-Foch, B.; Vignes-Adler, M.

2002-10-01

The collision of water drops against small targets was studied experimentally by means of a high-speed photography technique. The drop impact velocity was about 3.5 m/s. Drop diameters were in the range of 2.8-4.0 mm. The target was a stainless steel disk of 3.9 mm diameter. The drop spread beyond the target like a central cap surrounded by a thin, slightly conical lamella bounded by a thicker rim. By mounting a small obstacle near the target, surface-tension driven Mach waves in the flowing lamella were generated, which are formally equivalent to the familiar compressibility driven Mach waves in gas dynamics. From the measurement of the Mach angle, the values of some flow parameters could be obtained as functions of time, which provided insight into the flow structure. The liquid flowed from the central cap to the liquid rim through the thin lamella at constant momentum flux. At a certain stage of the process, most of the liquid accumulated in the rim and the internal part of the lamella became metastable. In this situation, a rupture wave propagating through the metastable internal part of the lamella caused the rim to retract while forming outwardly directed secondary jets. The jets disintegrated into secondary droplets due to the Savart-Plateau-Rayleigh instability. Prior to the end of the retraction, an internal circular wave of rupture was formed. It originated at the target and then it propagated to meet the retracting rim. Their meeting resulted in a crown of tiny droplets. A theoretical analysis of the ejection process is proposed.

CFD aspects of ADSS target design

International Nuclear Information System (INIS)

Shashi Kumar, G.N.; Mahendra, A.K.; Sanyal, A.; Gouthaman, G.

2004-03-01

The preliminary studies on CFD aspects of Accelerator Driven Sub-critical System (ADSS) target design has been presented in this report. The studies involve the thermal hydraulic analysis of the Liquid Metal Spallation Target (LMST) using Lead Bismuth Eutectic (LBE) as the target material. Apart from acting as Spallation medium LBE is used to remove the heat deposited by High Energy Proton Beam. Window of the target ( one side vacuum and other side LBE) has been reported in literature to be the most critical zone where high temperatures are reached. Numerical Simulations are carried out with Artificial Neural Network coupled Computational Fluid Dynamics (CFD) code, Various studies were carried out after the verification and validation of the initial results. Window being, the main parameter to be optimised, various designs of window were tried, along with change in the window material. The best possible combination has been proposed. The thermal hydraulic studies were carried out to arrive at the acceptable operating conditions for the target. (author)

Particle transfer spectroscopy using radioactive targets

CERN Document Server

Naumann, R A

1976-01-01

The practicality of general use of radioactive targets to study nuclei off the stability line by transfer spectroscopy is examined. Some advantages of this spectroscopic technique are illustrated with recent results from (p, t) and (t, p) stable target studies of negative parity core-coupled states systematically occurring in 4 adjacent odd silver isotopes. Preliminary results from the study of the /sup 205/Pb (t, p)/sup 207/Pb reaction using reactor produced 3*10/sup 7/ year lead 205 are given. (3 refs).

Determination of lead in treated crayfish Procambarus clarkii: accumulation in different tissues

Energy Technology Data Exchange (ETDEWEB)

Pastor, A.; Medina, J.; Del Ramo, J.; Torreblanca, A.; Diaz-Mayans, J.; Hernandez, F.

1988-09-01

The continual loading of trace metals into our environment represents a water pollution problem due to their toxic effects on aquatic biota. In addition, metal ions can be incorporated into food chains and concentrated by aquatic organisms to a level that affects their physiological state. There are several investigations on the toxic effects and bioaccumulation of lead in fishes, molluscs, and crustaceans. Lake Albufera (Valencia, Spain) and the surrounding rice-field waters are subjected to large loads of sewage and toxic industrial residues (including heavy metals) from many urban wastewaters in the area. In 1978, the American red crayfish Procambarus clarkii (Girard) appeared in Lake Albufera. The crayfish have reached a high density producing ecological and agricultural economic problems in rice crops. The crayfish is being fished commercially for human consumption without adequate protection to human health. The purpose of the present study was to investigate the accumulation of lead in tissues of the crayfish P. clarkii following short term lead exposure at several sublethal concentrations. The gills, midgut glands, antennal glands and muscle were analyzed by atomic absorption spectrophotometry.

The paradox of uranium development: A Polanyian analysis of social movements surrounding the Pinon Ridge Uranium Mill

Science.gov (United States)

Malin, Stephanie A.

Renewal of nuclear energy development has been proposed as one viable solution for reducing greenhouse gas emissions and impacts of climate change. This discussion became concrete as the first uranium mill proposed since the end of the Cold War, the Pinon Ridge Uranium Mill, received state permits in January 2011 to process uranium in southwest Colorado's Paradox Valley. Though environmental contamination from previous uranium activity caused one local community to be bulldozed to the ground, local support for renewed uranium activity emerges among local residents in communities like Nucla, Naturita, and Bedrock, Colorado. Regionally, however, a coalition of organized, oppositionbased grassroots groups fights the decision to permit the mill. Combined, these events allow social scientists a natural laboratory through which to view social repercussions of nuclear energy development. In this dissertation, I use a Polanyian theoretical framework to analyze social, political-economic, and environmental contexts of social movements surrounding PR Mill. My overarching research problem is: How might Polanyian double movement theory be applied to and made empirically testable within the social and environmental context of uranium development? I intended this analysis to inform energy policy debates regarding renewable energy. In Chapter 1, I found various forms of social dislocation lead to two divergent social movement outcomes. Economic social dislocation led to strong mill support among most local residents, according to archival, in-depth interview, and survey data. On the other hand, residents in regional communities experienced two other types of social dislocation -- another kind of economic dislocation, related to concern over boom-bust economies, and environmental health dislocations related to uranium exposure, creating conditions for a regional movement in opposition to PR Mill. In Chapter 2, I focus on regulations and find that two divergent social movements

TargetSpy: a supervised machine learning approach for microRNA target prediction.

Science.gov (United States)

Sturm, Martin; Hackenberg, Michael; Langenberger, David; Frishman, Dmitrij

2010-05-28

Virtually all currently available microRNA target site prediction algorithms require the presence of a (conserved) seed match to the 5' end of the microRNA. Recently however, it has been shown that this requirement might be too stringent, leading to a substantial number of missed target sites. We developed TargetSpy, a novel computational approach for predicting target sites regardless of the presence of a seed match. It is based on machine learning and automatic feature selection using a wide spectrum of compositional, structural, and base pairing features covering current biological knowledge. Our model does not rely on evolutionary conservation, which allows the detection of species-specific interactions and makes TargetSpy suitable for analyzing unconserved genomic sequences.In order to allow for an unbiased comparison of TargetSpy to other methods, we classified all algorithms into three groups: I) no seed match requirement, II) seed match requirement, and III) conserved seed match requirement. TargetSpy predictions for classes II and III are generated by appropriate postfiltering. On a human dataset revealing fold-change in protein production for five selected microRNAs our method shows superior performance in all classes. In Drosophila melanogaster not only our class II and III predictions are on par with other algorithms, but notably the class I (no-seed) predictions are just marginally less accurate. We estimate that TargetSpy predicts between 26 and 112 functional target sites without a seed match per microRNA that are missed by all other currently available algorithms. Only a few algorithms can predict target sites without demanding a seed match and TargetSpy demonstrates a substantial improvement in prediction accuracy in that class. Furthermore, when conservation and the presence of a seed match are required, the performance is comparable with state-of-the-art algorithms. TargetSpy was trained on mouse and performs well in human and drosophila

TargetSpy: a supervised machine learning approach for microRNA target prediction

Directory of Open Access Journals (Sweden)

Langenberger David

2010-05-01

Full Text Available Abstract Background Virtually all currently available microRNA target site prediction algorithms require the presence of a (conserved seed match to the 5' end of the microRNA. Recently however, it has been shown that this requirement might be too stringent, leading to a substantial number of missed target sites. Results We developed TargetSpy, a novel computational approach for predicting target sites regardless of the presence of a seed match. It is based on machine learning and automatic feature selection using a wide spectrum of compositional, structural, and base pairing features covering current biological knowledge. Our model does not rely on evolutionary conservation, which allows the detection of species-specific interactions and makes TargetSpy suitable for analyzing unconserved genomic sequences. In order to allow for an unbiased comparison of TargetSpy to other methods, we classified all algorithms into three groups: I no seed match requirement, II seed match requirement, and III conserved seed match requirement. TargetSpy predictions for classes II and III are generated by appropriate postfiltering. On a human dataset revealing fold-change in protein production for five selected microRNAs our method shows superior performance in all classes. In Drosophila melanogaster not only our class II and III predictions are on par with other algorithms, but notably the class I (no-seed predictions are just marginally less accurate. We estimate that TargetSpy predicts between 26 and 112 functional target sites without a seed match per microRNA that are missed by all other currently available algorithms. Conclusion Only a few algorithms can predict target sites without demanding a seed match and TargetSpy demonstrates a substantial improvement in prediction accuracy in that class. Furthermore, when conservation and the presence of a seed match are required, the performance is comparable with state-of-the-art algorithms. TargetSpy was trained on

Rain Simulation for the Test of Automotive Surround Sensors

Science.gov (United States)

Hasirlioglu, Sinan; Riener, Andreas; Doric, Igor

2017-04-01

The WHO Global Health Observatory data indicates that over 1.25 million people die in traffic accidents annually. To save lives, car manufacturers spend lot of efforts on the development of novel safety systems aiming to avoid or mitigate accidents and provide maximum protection for vehicle occupants as well as vulnerable road users. All the safety features mainly rely on data from surround sensors such as radar, lidar and camera and intelligent vehicles today use these environmental data for instant decision making and vehicle control. As already small errors in sensor data measurements could lead to catastrophes like major injuries or road traffic fatalities, it is of utmost importance to ensure high reliability and accuracy of sensors and safety systems. This work focuses on the influence of environmental factors such as rain conditions, as it is known that rain drops scatter the electromagnetic waves. The result is incorrect measurements with a direct negative impact on environment detection. To identify potential problems of sensors under varying environmental conditions, systems are today tested in real-world settings with two main problems: First, tests are time-consuming and second, environmental conditions are not reproducible. Our approach to test the influence of weather on automotive sensors is to use an indoor rain simulator. Our artificial rain maker, installed at CARISSMA (Center of Automotive Research on Integrated Safety Systems and Measurement Area), is parametrized with rain characteristics measured in the field using a standard disdrometer. System behavior on artificial rain is compared and validated with natural rainfall. With this simulator it is finally possible to test environmental influence at various levels and under reproducible conditions. This saves lot of efforts required for the test process itself and furthermore has a positive impact on the reliability of sensor systems due to the fact that test driven development is enabled.

Structure and properties of optical-discharge plasma in CO2-laser beam near target surface

Science.gov (United States)

Danshchikov, Ye. V.; Dymshakov, V. A.; Lebedev, F. V.; Ryazanov, A. V.

1986-05-01

An experimental study of optical-discharge plasma in a CO2-laser beam at a target surface was made for the purpose of exploring the not yet understood role of this plasma in the laser-target interaction process. Such a plasma was produced by means of a quasi-continuous CO2-laser with an unstable resonator, its power being maintained constant for 1 ms periods. Its radiation was focused on the surfaces of thick and seeding thin Al, Ti, and Ta targets inclined at an approximately 70 deg. angle to the beam, inside a hermetic chamber containing air, argon, or helium under atmospheric pressure. The radiation intensity distribution over the focal plane and the nearest caustic surface in the laser beam was measured along with the plasma parameters, the latter by the methods of spectral analysis and photoelectric recording. The instrumentation for this purpose included an MDR-3 monochromator with an entrance slit, a double electron-optical converter, a memory oscillograph, and an SI-10-30 ribbon lamp as radiation reference standard. The results yielded integral diametral intensity distributions of the emission lines Ti-II (457.2 nm), Ti-I (464 nm), Ar-II (462 nm), radial and axial temperature profiles of optical discharge in metal vapor in surrounding gas, and the radial temperature profile of irradiated metal surface at successive instants of time. The results reveal marked differences between the structures and the properties of optical-discharge plasma in metal vapor and in surrounding gas, optical discharge in the former being characterized by localization within the laser beam and optical discharge in the latter being characterized by a drift away from the target.

CT after gastrectomy for gastric carcinoma : significance of soft tissue surrounding the celiac axis

International Nuclear Information System (INIS)

Baek, Seung Yon; Kim, Hae Young; Choi, Hye Young; Lee, Sun Wha; Ko, Eun Joo; Lee, Myung Sook

1997-01-01

To evaluate whether soft tissue surrounding the celiac axis, as seen on abdominal CT imaging after gastrectomy for gastric carcinoma, should be considered as the recurrence of carcinoma or postoperative change. One hundred and forty-one abdominal CT examinations of 71 patients who had undergone subtotal or total gastrectomy for gastric carcinoma were included in our study. Conventional CT scans were obtained with 1cm thickness and interval from the diaphragm to the kidneys after contrast enhancement. It was considered that carcinoma had not recurred if findings were negative on UGI series, endoscopy with biopsy and a normal level of carcinoembryonic antigen except for soft tissue surrounding the celiac axis on abdominal CT. We then divided subjects into a recurrence group(N=20) and normal group(N=51) and on initial follow-up CT(FU-CT), analyzed the incidence, margin, shape, extent, degree and pattern of attenuation of the soft tissue surrounding the celiac axis in both groups. Since the second FU-CT examination, we observed changes in the soft tissue surrounding the celiac axis. On initial follow-up CT, at mean 308 days after surgery, fifty-five percent(39/71) of total patients (70%(14/20) of the recurrence group and 49%(25/51) of the normal group) showed soft tissue surrounding the celiac axis. The margin was distinct in 12(86%) of the recurrence group and indistinct in 21(84%) of the normal group(p<0.001). Twelve (86%) of the recurrence group showed a nodular or confluent nodular shape and 21(84%) of the normal group showed a permeative shape (p<0.001). Extent was unilateral in eight (57%) of the recurrence group and bilateral in 16(64%) of the normal group. Attenuation was similar to that of the spleen and muscle in seven(50%) of the recurrence group and was similar to that of muscle in 18(72%) of the normal group. The pattern of attenuation was homogeneous in 13(93%) of the recurrence group and 21(84%) of the normal group. There was no significant difference in

Assessment of metals pollution on agricultural soil surrounding a lead-zinc mining area in the Karst region of Guangxi, China.

Science.gov (United States)

Zhang, Chaolan; Li, Zhongyi; Yang, Weiwei; Pan, Liping; Gu, Minghua; Lee, DoKyoung

2013-06-01

Soil samples were collected on farmland in a lead-zinc mining area in the Karst region of Guangxi, China. The contamination of the soil by eight metals (Cd, Hg, As, Cu, Pb, Cr, Zn, Ni) was determined. Among all these metals, Cd is the most serious pollutant in this area. Zn, Hg as well asPb can also be measured at high levels, which may affect the crop production. All other metals contributed marginally to the overall soil contamination. Besides the evaluation of single metals, the Nemerow synthetic index indicated that the soil is not suitable for agricultural use.

Structure and Chemical Durability of Lead Crystal Glass.

Science.gov (United States)

Angeli, Frédéric; Jollivet, Patrick; Charpentier, Thibault; Fournier, Maxime; Gin, Stéphane

2016-11-01

Silicate glasses containing lead, also called lead crystal glasses, are commonly used as food product containers, in particular for alcoholic beverages. Lead's health hazards require major attention, which can first be investigated through the understanding of Pb release mechanisms in solution. The behavior of a commercial crystal glass containing 10.6 mol % of PbO (28.3 wt %) was studied in a reference solution of 4% acetic acid at 22, 40, and 70 °C at early and advanced stages of reaction. High-resolution solid-state 17 O and 29 Si NMR was used to probe the local structure of the pristine and, for the first time, of the altered lead crystal glass. Inserted into the vitreous structure between the network formers as Si-O-Pb bonds, Pb does not form Pb-O-Pb clusters which are expected to be more easily leached. A part of K is located near Pb, forming mixed Si-O-(Pb,K) near the nonbridging oxygens. Pb is always released into the solution following a diffusion-controlled dissolution over various periods of time, at a rate between 1 and 2 orders of magnitude lower than the alkalis (K and Na). The preferential release of alkalis is followed by an in situ repolymerization of the silicate network. Pb is only depleted in the outermost part of the alteration layer. In the remaining part, it stays mainly surrounded by Si in a stable structural configuration similar to that of the pristine glass. A simple model is proposed to estimate the Pb concentration as a function of glass surface, solution volume, temperature, and contact time.

LIFE Target Fabrication Research Plan Sept 2008

Energy Technology Data Exchange (ETDEWEB)

Miles, R; Biener, J; Kucheyev, S; Montesanti, R; Satcher, J; Spadaccini, C; Rose, K; Wang, M; Hamza, A; Alexander, N; Brown, L; Hund, J; Petzoldt, R; Sweet, W; Goodin, D

2008-11-10

The target-system for the baseline LIFE fast-ignition target was analyzed to establish a preliminary estimate for the costs and complexities involved in demonstrating the technologies needed to build a prototype LIFE plant. The baseline fast-ignition target upon which this analysis was developed is shown in Figure 1.0-1 below. The LIFE target-system incorporates requirements for low-cost, high throughput manufacture, high-speed, high accuracy injection of the target into the chamber, production of sufficient energy from implosion and recovery and recycle of the imploded target material residue. None of these functions has been demonstrated to date. Existing target fabrication techniques which lead to current 'hot spot' target costs of {approx}$100,000 per target and at a production rate of 2/day are unacceptable for the LIFE program. Fabrication techniques normally used for low-cost, low accuracy consumer products such as toys must be adapted to the high-accuracy LIFE target. This will be challenge. A research program resulting is the demonstration of the target-cycle technologies needed for a prototype LIFE reactor is expected to cost {approx}$51M over the course of 5 years. The effort will result in targets which will cost an estimated $0.23/target at a rep-rate of 20 Hz or about 1.73M targets/day.

Biophysics: for HTS hit validation, chemical lead optimization, and beyond.

Science.gov (United States)

Genick, Christine C; Wright, S Kirk

2017-09-01

There are many challenges to the drug discovery process, including the complexity of the target, its interactions, and how these factors play a role in causing the disease. Traditionally, biophysics has been used for hit validation and chemical lead optimization. With its increased throughput and sensitivity, biophysics is now being applied earlier in this process to empower target characterization and hit finding. Areas covered: In this article, the authors provide an overview of how biophysics can be utilized to assess the quality of the reagents used in screening assays, to validate potential tool compounds, to test the integrity of screening assays, and to create follow-up strategies for compound characterization. They also briefly discuss the utilization of different biophysical methods in hit validation to help avoid the resource consuming pitfalls caused by the lack of hit overlap between biophysical methods. Expert opinion: The use of biophysics early on in the drug discovery process has proven crucial to identifying and characterizing targets of complex nature. It also has enabled the identification and classification of small molecules which interact in an allosteric or covalent manner with the target. By applying biophysics in this manner and at the early stages of this process, the chances of finding chemical leads with novel mechanisms of action are increased. In the future, focused screens with biophysics as a primary readout will become increasingly common.

Characterization of polychlorinated dibenzo-p-dioxins and dibenzofurans, dioxin-like polychlorinated biphenyls, and polychlorinated naphthalenes in the environment surrounding secondary copper and aluminum metallurgical facilities in China.

Science.gov (United States)

Hu, Jicheng; Zheng, Minghui; Liu, Wenbin; Nie, Zhiqiang; Li, Changliang; Liu, Guorui; Xiao, Ke

2014-10-01

Unintentionally produced persistent organic pollutants (UP-POPs) were determined in ambient air from around five secondary non-ferrous metal processing plants in China, to investigate the potential impacts of the emissions of these plants on their surrounding environments. The target compounds were polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs). The PCDD/F, dl-PCB, and PCN concentrations in the ambient air downwind of the plants were 4.70-178, 8.23-7520 and 152-4190 pg/m(3), respectively, and the concentrations upwind of the plants were lower. Clear correlations were found between ambient air and stack gas concentrations of the PCDD/Fs, dl-PCBs, and PCNs among the five plants, respectively. Furthermore, the UP-POPs homolog and congener patterns in the ambient air were similar to the patterns in the stack gas samples. These results indicate that UP-POPs emissions from the plants investigated have obvious impacts on the environments surrounding the plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pharmacogenomics of GPCR Drug Targets

DEFF Research Database (Denmark)

Hauser, Alexander Sebastian; Chavali, Sreenivas; Masuho, Ikuo

2018-01-01

Natural genetic variation in the human genome is a cause of individual differences in responses to medications and is an underappreciated burden on public health. Although 108 G-protein-coupled receptors (GPCRs) are the targets of 475 (∼34%) Food and Drug Administration (FDA)-approved drugs...... and account for a global sales volume of over 180 billion US dollars annually, the prevalence of genetic variation among GPCRs targeted by drugs is unknown. By analyzing data from 68,496 individuals, we find that GPCRs targeted by drugs show genetic variation within functional regions such as drug......- and effector-binding sites in the human population. We experimentally show that certain variants of μ-opioid and Cholecystokinin-A receptors could lead to altered or adverse drug response. By analyzing UK National Health Service drug prescription and sales data, we suggest that characterizing GPCR variants...

An improved model for surround suppression by steerable filters and multilevel inhibition with application to contour detection

NARCIS (Netherlands)

Papari, Giuseppe; Petkov, Nicolai

Psychophysical and neurophysiological evidence about the human visual system shows the existence of a mechanism, called surround suppression, which inhibits the response of an edge in the presence of other similar edges in the surroundings. A simple computational model of this phenomenon has been

Ornitocenosis of the Sursky pond and its close the surroundings

International Nuclear Information System (INIS)

Lacko, J.; Ambrus, B.; Fupso, A.

2013-01-01

The paper focuses on the qualitative-quantitative research of fishpond bird community of the Sursky and its surroundings as well as on analysis of seasonal population dynamics of the avifauna as well as on placing the determined species into environmental groups and guilds. Another object is the comparison of our results with recent work focused on research of bird communities on this site.

Experiences during the decontamination process of areas surrounding to Fukushima

International Nuclear Information System (INIS)

Molina, G.

2014-10-01

In this work the experience gained during the decontamination of areas surrounding to Fukushima NPP, rugged during the earthquake and tsunami in 2011 and caused the contamination with fission products in these areas is described. Actions taken by the Japanese government are reported and some of the techniques used, the intervention levels and the progress made and disposal techniques considered are presented. (Author)

Isoperimetric inequalities in surround system and space science

OpenAIRE

JiaJin Wen; Jun Yuan; ShanHe Wu

2016-01-01

Abstract By means of the algebraic, analysis, convex geometry, computer, and inequality theories we establish the following isoperimetric inequality in the centered 2-surround system S ( 2 ) { P , Γ , l } $S^{(2)} \\{P,\\varGamma ,l \\}$ : ( 1 | Γ | ∮ Γ r ¯ P p ) 1 / p ⩽ | Γ | 4 π sin l π | Γ | [ csc l π | Γ | + cot 2 l π | Γ | ln ( tan l π | Γ | + sec l π | Γ | ) ] , ∀ p ⩽ − 2 . $$\\begin{aligned}& \\biggl(\\frac{1}{|\\varGamma |} \\oint_{\\varGamma }\\bar{r}_{P}^{p} \\biggr)^{1/p}\\leqslant\\frac{|\\varG...

Towards Semantic Understanding of Surrounding Vehicular Maneuvers

DEFF Research Database (Denmark)

Kristoffersen, Miklas Strøm; Dueholm, Jacob Velling; Satzoda, Ravi K.

2016-01-01

This paper proposes the use of multiple low-cost visual sensors to obtain a surround view of the ego-vehicle for semantic understanding. A multi-perspective view will assist the analysis of naturalistic driving studies (NDS), by automating the task of data reduction of the observed sequences...... into events. A user-centric vision-based framework is presented using a vehicle detector and tracker in each separate perspective. Multi-perspective trajectories are estimated and analyzed to extract 14 different events, including potential dangerous behaviors such as overtakes and cut-ins. The system...... is tested on ten sequences of real-world data collected on U. S. highways. The results show the potential use of multiple low-cost visual sensors for semantic understanding around the ego-vehicle....

Migration of metallic ions from screwposts into dentin and surrounding tissues

International Nuclear Information System (INIS)

Arvidson, K.; Wroblewski, R.

1978-01-01

Previous investigations have shown that corrosion and other electrochemical processes occur when different alloys or metals are found together in the same mouth. In the present report, when teeth were restored using non-noble metallic posts, the metals diffused out to surrounding hard and soft connective tissues. The material consisted of extracted teeth with screwposts and surrounding discolored connective tissues. The screwposts had been cemented to the teeth 3-10 years earlier. The distribution of metal ion was determined by means of energy-dispersive X-ray microanalysis. Copper and zinc were found in both hard and soft tissues. Relatively high concentrations of copper ions were identified in areas of the teeth with blue-green discolorations. Zinc ions were detected in the dentin; they most probably originated from the screwposts and the cement, but zinc is also found in normal human dentin. Copper, zinc, silver and iron were found in the dark discolorations of the gingiva adjacent to the extracted teeth. (author)

Targeting the extracellular matrix to disrupt cancer progression

Directory of Open Access Journals (Sweden)

Freja Albjerg Venning

2015-10-01

Full Text Available Metastatic complications are responsible for more than 90% of cancer related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multi-step process, with each step involving intricate cross-talk between the cancer cells and their non-cellular surroundings, the extracellular matrix (ECM. Many ECM proteins are significantly de-regulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread is summarized. In addition, we highlight the promising (pre-clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression.

Status of the Spallation Neutron Source with focus on target materials

International Nuclear Information System (INIS)

Mansur, L.K.; Haines, J.R.

2006-01-01

An overview of the design and construction of the Spallation Neutron Source (SNS) is presented. Key facility performance parameters are summarized and plans for initial operation are described. Early efforts produced a conceptual design in 1997; the project itself was initiated in 1999, with the official groundbreaking taking place in December of 1999. As of April 2005 building construction was complete and the overall project was more than 90% complete. The design of the target and surrounds are finished and the first target was installed in June 2005. First beam on target is expected in June, 2006. The engineering design of the target region is described. The key systems comprise the mercury target, moderator and reflector assemblies, remote handling systems, utilities and shielding. Through interactions with the 1 GeV proton beam, the target, moderators and reflectors produce short pulse neutrons in thermal energy ranges, which are transported to a variety of neutron scattering instruments. The mercury target module itself is described in more detail. Materials issues are expected to govern the overall lifetime and have influenced the design, fabrication and planned operation. A wide range of materials research and development has been carried out to provide experimental data and analyses to ensure the satisfactory performance of the target and to set initial design conditions. Materials R and D concentrated mainly on cavitation erosion, radiation effects, and mercury compatibility issues, including investigations of the mechanical properties during exposure to mercury. Questions that would require future materials research are discussed

The OPERA experiment Target Tracker

CERN Document Server

Adam, T; Borer, K.; Campagne, Jean-Eric; Con-Sen, N.; de La Taille, C.; Dick, N.; Dracos, M.; Gaudiot, G.; Goeltzenlichter, T.; Gornushkin, Y.; Grapton, J.-N.; Guyonnet, J.-L.; Hess, M.; Igersheim, R.; Janicsko Csathy, J.; Jollet, C.; Juget, F.; Kocher, H.; Krasnoperov, A.; Krumstein, Z.; Martin-Chassard, G.; Moser, U.; Nozdrin, A.; Olchevski, A.; Porokhovoi, S.; Raux, L.; Sadovski, A.; Schuler, J.; Schutz, H.-U.; Schwab, C.; Smolnikov, A.; Van Beek, G.; Vilain, P.; Walchli, T.; Wilquet, G.; Wurtz, J.

2007-01-01

The main task of the Target Tracker detector of the long baseline neutrino oscillation OPERA experiment is to locate in which of the target elementary constituents, the lead/emulsion bricks, the neutrino interactions have occurred and also to give calorimetric information about each event. The technology used consists in walls of two planes of plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multi-anode photomultiplier tubes. All the elements used in the construction of this detector and its main characteristics are described.

Systemic Therapy for Merkel Cell Carcinoma: What’s on the Horizon?

Energy Technology Data Exchange (ETDEWEB)

Rabinowits, Guilherme [Dana-Farber Cancer Institute, Harvard Medical School, Department of Medical Oncology, Center for Head and Neck Oncology, 450 Brookline Avenue, Boston, MA 02215 (United States)

2014-05-16

Merkel cell carcinoma is an aggressive neuroendocrine skin cancer that usually affects elderly patients. Despite being uncommon, incidence has been steadily increasing over the last two decades, likely due to increased awareness, better diagnostic methods and aging of the population. It is currently one of the most lethal cutaneous malignancies, with a five-year overall survival of approximately 50%. With the better understanding of the molecular pathways that lead to the development of Merkel cell carcinoma, there has been an increasing excitement and optimism surrounding novel targeted therapies, in particular to immunotherapy. Some of the concepts surrounding the novel targeted therapies and currently ongoing clinical trials are reviewed here.

Systemic Therapy for Merkel Cell Carcinoma: What’s on the Horizon?

International Nuclear Information System (INIS)

Rabinowits, Guilherme

2014-01-01

Merkel cell carcinoma is an aggressive neuroendocrine skin cancer that usually affects elderly patients. Despite being uncommon, incidence has been steadily increasing over the last two decades, likely due to increased awareness, better diagnostic methods and aging of the population. It is currently one of the most lethal cutaneous malignancies, with a five-year overall survival of approximately 50%. With the better understanding of the molecular pathways that lead to the development of Merkel cell carcinoma, there has been an increasing excitement and optimism surrounding novel targeted therapies, in particular to immunotherapy. Some of the concepts surrounding the novel targeted therapies and currently ongoing clinical trials are reviewed here

Target Glint Suppression Technology.

Science.gov (United States)

1980-09-01

Rayleigh for either horizontal or vertical polarization). 2.1.2 Spatial Characterization. Before the effects of diversity on target detection can be...ncs) dRCS T If the lower intergration limit is taken as zero for the Rayleigh targct model of interest, then this quantity is unbounded. In...port wing, inner section Trailing edge of starboard .:ing, inner section Leading edge of horizontal stabilizer, inner section, port side TLeal, -g

The lithosphere-asthenosphere Italy and surroundings

CERN Document Server

Panza, G F; Chimera, G; Pontevivo, A; Raykova, R

2003-01-01

The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by surface wave velocity tomography and non-linear inversion. Maps of the Moho depth, of the thickness of the lithosphere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, identified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the principal recent volcanoes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria a lithospheric doubling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenosphere properties delineat...

Multifunctional Nanocarriers for diagnostics, drug delivery and targeted treatment across blood-brain barrier: perspectives on tracking and neuroimaging

Directory of Open Access Journals (Sweden)

Estrada Giovani

2010-03-01

Full Text Available Abstract Nanotechnology has brought a variety of new possibilities into biological discovery and clinical practice. In particular, nano-scaled carriers have revolutionalized drug delivery, allowing for therapeutic agents to be selectively targeted on an organ, tissue and cell specific level, also minimizing exposure of healthy tissue to drugs. In this review we discuss and analyze three issues, which are considered to be at the core of nano-scaled drug delivery systems, namely functionalization of nanocarriers, delivery to target organs and in vivo imaging. The latest developments on highly specific conjugation strategies that are used to attach biomolecules to the surface of nanoparticles (NP are first reviewed. Besides drug carrying capabilities, the functionalization of nanocarriers also facilitate their transport to primary target organs. We highlight the leading advantage of nanocarriers, i.e. their ability to cross the blood-brain barrier (BBB, a tightly packed layer of endothelial cells surrounding the brain that prevents high-molecular weight molecules from entering the brain. The BBB has several transport molecules such as growth factors, insulin and transferrin that can potentially increase the efficiency and kinetics of brain-targeting nanocarriers. Potential treatments for common neurological disorders, such as stroke, tumours and Alzheimer's, are therefore a much sought-after application of nanomedicine. Likewise any other drug delivery system, a number of parameters need to be registered once functionalized NPs are administered, for instance their efficiency in organ-selective targeting, bioaccumulation and excretion. Finally, direct in vivo imaging of nanomaterials is an exciting recent field that can provide real-time tracking of those nanocarriers. We review a range of systems suitable for in vivo imaging and monitoring of drug delivery, with an emphasis on most recently introduced molecular imaging modalities based on optical

More target features in visual working memory leads to poorer search guidance: Evidence from contralateral delay activity

OpenAIRE

Schmidt, Joseph; MacNamara, Annmarie; Proudfit, Greg Hajcak; Zelinsky, Gregory J.

2014-01-01

The visual-search literature has assumed that the top-down target representation used to guide search resides in visual working memory (VWM). We directly tested this assumption using contralateral delay activity (CDA) to estimate the VWM load imposed by the target representation. In Experiment 1, observers previewed four photorealistic objects and were cued to remember the two objects appearing to the left or right of central fixation; Experiment 2 was identical except that observers previewe...

Parkinson's disease proteins: Novel mitochondrial targets for cardioprotection

OpenAIRE

Mukherjee, Uma A.; Ong, Sang-Bing; Ong, Sang-Ging; Hausenloy, Derek J.

2015-01-01

Ischemic heart disease (IHD) is the leading cause of death and disability worldwide. Therefore, novel therapeutic targets for protecting the heart against acute ischemia/reperfusion injury (IRI) are required to attenuate cardiomyocyte death, preserve myocardial function, and prevent the onset of heart failure. In this regard, a specific group of mitochondrial proteins, which have been linked to familial forms of Parkinson's disease (PD), may provide novel therapeutic targets for cardioprotect...

Development of targeted STORM for super resolution imaging of biological samples using digital micro-mirror device

Science.gov (United States)

Valiya Peedikakkal, Liyana; Steventon, Victoria; Furley, Andrew; Cadby, Ashley J.

2017-12-01

We demonstrate a simple illumination system based on a digital mirror device which allows for fine control over the power and pattern of illumination. We apply this to localization microscopy (LM), specifically stochastic optical reconstruction microscopy (STORM). Using this targeted STORM, we were able to image a selected area of a labelled cell without causing photo-damage to the surrounding areas of the cell.

EURAC: A liquid target neutron spallation

Energy Technology Data Exchange (ETDEWEB)

Perlado, J.M.; Minguez, E.; Sanz, J. [Universidad Politecnica de Madrid (Spain)] [and others

1995-10-01

Euratom/JRC Ispra led some years ago the design of an accelerator based neutron spallation source EURAC, with special emphasis as a fusion material testing device. DENIM was involved in the development of the last version of this source. EURAC proposes to use a beam of 600 MeV or 1.5 GeV protons, produced by an effective and low cost ring cyclotron with a current of 6 mA impinging in a liquid lead, or lead-bismuth, target. It will use an advanced cyclotron technology which can be implemented in the next future, in the line of the actual technology of the upgraded SIN-type cyclotron. The adjacent rows to the target correspond to the lead, or Li{sub 17}Pb{sub 83}, cooled channels where the samples will be located. The available volumes there were shown enough for material testing purposes. Here, proposal of using those experimental areas to introduce small masses of radioactive wastes for testing of transmutation in spallation source is made. In addition, extrapolation of present conceptual design to make available larger volumes under flexible conditions seems to be possible. Neutrons leaking from the test zone drive a subcritical booster (<10 MW) which could provide a thermal neutron flux trap with a liquid hydrogen moderator in the center.

Search for Fractionally Charged Nuclei in High-Energy Oxygen-Lead Collisions

CERN Multimedia

2002-01-01

We propose to use stacks of CR-39 plastic track detectors to look for fractionally charged projectile fragments produced in collisions of high-energy oxygen, sulfur, and calcium nuclei with a lead target. The expected charge resolution is @s^z~=~0.06e for fragments with 17e/3~@$<$~Z~@$<$~23e/3. We request that two target + stack assemblies be exposed to 1~x~10|5 oxygen nuclei at maximum available energy.

Diversity of vascular plants of Piestany and surroundings (presentation)

International Nuclear Information System (INIS)

Penzesova, A.; Galusova, T.

2013-01-01

In this presentation is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

Drug-target interaction prediction via class imbalance-aware ensemble learning.

Science.gov (United States)

Ezzat, Ali; Wu, Min; Li, Xiao-Li; Kwoh, Chee-Keong

2016-12-22

Multiple computational methods for predicting drug-target interactions have been developed to facilitate the drug discovery process. These methods use available data on known drug-target interactions to train classifiers with the purpose of predicting new undiscovered interactions. However, a key challenge regarding this data that has not yet been addressed by these methods, namely class imbalance, is potentially degrading the prediction performance. Class imbalance can be divided into two sub-problems. Firstly, the number of known interacting drug-target pairs is much smaller than that of non-interacting drug-target pairs. This imbalance ratio between interacting and non-interacting drug-target pairs is referred to as the between-class imbalance. Between-class imbalance degrades prediction performance due to the bias in prediction results towards the majority class (i.e. the non-interacting pairs), leading to more prediction errors in the minority class (i.e. the interacting pairs). Secondly, there are multiple types of drug-target interactions in the data with some types having relatively fewer members (or are less represented) than others. This variation in representation of the different interaction types leads to another kind of imbalance referred to as the within-class imbalance. In within-class imbalance, prediction results are biased towards the better represented interaction types, leading to more prediction errors in the less represented interaction types. We propose an ensemble learning method that incorporates techniques to address the issues of between-class imbalance and within-class imbalance. Experiments show that the proposed method improves results over 4 state-of-the-art methods. In addition, we simulated cases for new drugs and targets to see how our method would perform in predicting their interactions. New drugs and targets are those for which no prior interactions are known. Our method displayed satisfactory prediction performance and was

Nanobody-photosensitizer conjugates for targeted photodynamic therapy

NARCIS (Netherlands)

Heukers, Raimond; van Bergen en Henegouwen, P; Oliveira, Sabrina

2014-01-01

Photodynamic therapy (PDT) induces cell death through light activation of a photosensitizer (PS). Targeted delivery of PS via monoclonal antibodies has improved tumor selectivity. However, these conjugates have long half-lives, leading to relatively long photosensitivity in patients. In an attempt

Target based drug design - a reality in virtual sphere.

Science.gov (United States)

Verma, Saroj; Prabhakar, Yenamandra S

2015-01-01

The target based drug design approaches are a series of computational procedures, including visualization tools, to support the decision systems of drug design/discovery process. In the essence of biological targets shaping the potential lead/drug molecules, this review presents a comprehensive position of different components of target based drug design which include target identification, protein modeling, molecular dynamics simulations, binding/catalytic sites identification, docking, virtual screening, fragment based strategies, substructure treatment of targets in tackling drug resistance, in silico ADMET, structural vaccinology, etc along with the key issues involved therein and some well investigated case studies. The concepts and working of these procedures are critically discussed to arouse interest and to advance the drug research.

Leading, but not trailing, primes influence temporal order perception: further evidence for an attentional account of perceptual latency priming.

Science.gov (United States)

Scharlau, Ingrid

2002-11-01

Presenting a masked prime leading a target influences the perceived onset of the masking target (perceptual latency priming; Scharlau & Neumann, in press). This priming effect is explained by the asynchronous updating model (Neumann, 1982; Scharlau & Neumann, in press): The prime initiates attentional allocation toward its location, which renders a trailing target at the same place consciously available earlier. In three experiments, this perceptual latency priming by leading primes was examined jointly with the effects of trailing primes in order to compare the explanation of the asynchronous updating model with the onset-averaging and the P-center hypotheses. Experiment 1 showed that an attended, as well as an unattended, prime leads to perceptual latency priming. In addition, a large effect of trailing primes on the onset of a target was found. As Experiment 2 demonstrated, this effect is quite robust, although smaller than that of a leading prime. In Experiment 3, masked primes were used. Under these conditions, no influence of trailing primes could be found, whereas perceptual latency priming persisted. Thus, a nonattentional explanation for the effect of trailing primes seems likely.

Heavy ion fusion targets; issues for fast ignition

International Nuclear Information System (INIS)

Bangerter, Roger O.

2014-01-01

During the last 36 years researchers have suggested and evaluated a large number of target designs for heavy ion inertial fusion. The different target designs can be classified according to their mode of ignition, their method of implosion, and their size. Ignition modes include hot-spot ignition and fast ignition. Methods of implosion include direct drive and indirect drive. Historically there has been significant work on indirectly driven targets with hot-spot ignition. Recently there has been increasing interest in directly driven targets with ion driven fast ignition. In principle, fast ignition might lead to improved target performance. On the other hand, fast ignition imposes stringent requirements on accelerators and beam physics. Furthermore, fast ignition magnifies the importance of a number of traditional target physics issues associated with ion beam energy deposition and fuel preheat. This paper will discuss the advantages and disadvantages of the various classes of targets. It will also discuss some issues that must be resolved to assess the feasibility of ion fast ignition

Assessment of land degradation and its spatial and temporal variation in Beijing surrounding area

Science.gov (United States)

Li, Shuang; Dong, Suocheng; Zhang, Xiaojun; Zhiqiang, Gao

2005-08-01

The indulgence in willful persecution of sandstorm had made great attention of many countries around the world. Chinese government and the Chinese academy of science going with some other countries have devoted a large amount of vigor to study the crucial environment problem. Due to the main source areas of sandstorm all located in the arid and semi-arid regions where there have great area, hard natural condition and bad traffic condition, it's very difficult to accomplish source area and the reason of sandstorm. For this destination, a international cooperation organization has been established to clarify the occur mechanism, transfer process and the following environment impact of sandstorm. The organization includes many researchers come form USA, Japan, Korea, and so on. Beijing surrounding area is one of the main sandstorm sources in recent years. In order to understand fully of the sandstorm form and development, we analyzed the land use degradation of Beijing surrounding area during the last ten years. 71 scenes Landsat TM/ETM, 611 scenes DRG and DEM data had been processed in our study. This paper made a detail describe of using Landsat image data and high resolution DEM data to construe the soil erosion and vegetation degenerate. The result shows that the irrational human activities and land use style are the main factors of land use degradation. In case of Beijing surrounding area, the land degradation directly impacted the frequency and intensity of sand & dust storm in Northern China. The case study region of Beijing surrounding area includes 51 counties that belong to three provinces and autonomous regions.

Neutronic performances of the MEGAPIE target

Energy Technology Data Exchange (ETDEWEB)

Panebianco, S.; Bringer, O.; Chabod, S.; Dupont, E.; Letourneau, A. [CEA Saclay, Dept. d' Astrophysique de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee (DSM/DAPNIA/SPhN), 91- Gif sur Yvette (France); Beauvais, P.; Lotrus, P.; Molinie, F.; Toussaint, J.Ch. [CEA Saclay, Dept. d' Astrophysique de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee (DSM/DAPNIA), 91- Gif sur Yvette (France); Chartier, F. [CEA Saclay, Dept. de Physico-Chimie (DEN/DPC/SECR), 91 - Gif sur Yvette (France); Oriol, L. [CEA Cadarache, Dept. d' Etudes des Reacteurs (DEN/DER/SPEX), 13 - Saint Paul lez Durance (France)

2008-07-01

The MEGAPIE project is a key experiment on the road to Accelerator Driven Systems and it provides the scientific community with unique data on the behavior of a liquid lead-bismuth spallation target under realistic and long term irradiation conditions. The neutronic of such target is of course of prime importance when considering its final destination as an intense neutron source. This is the motivation to characterize the inside neutron flux of the target in operation. A complex detector, made of 8 'micro' fission-chambers, has been built and installed in the core of the target, few tens of centimeters from the proton/Pb-Bi interaction zone. This detector is designed to measure the absolute neutron flux inside the target, to give its spatial distribution and to correlate its temporal variations with the beam intensity. Moreover, integral information on the neutron energy distribution as a function of the position along the beam axis could be extracted, giving integral constraints on the neutron production models implemented in transport codes such as MCNPX. (authors)

Dissipation of Impact Stress Waves within the Artificial Blasting Damage Zone in the Surrounding Rocks of Deep Roadway

Directory of Open Access Journals (Sweden)

Jianguo Ning

2016-01-01

Full Text Available Artificial explosions are commonly used to prevent rockburst in deep roadways. However, the dissipation of the impact stress wave within the artificial blasting damage zone (ABDZ of the rocks surrounding a deep roadway has not yet been clarified. The surrounding rocks were divided into the elastic zone, blasting damage zone, plastic zone, and anchorage zone in this research. Meanwhile, the ABDZ was divided into the pulverizing area, fractured area, and cracked area from the inside out. Besides, the model of the normal incidence of the impact stress waves in the ABDZ was established; the attenuation coefficient of the amplitude of the impact stress waves was obtained after it passed through the intact rock mass, and ABDZ, to the anchorage zone. In addition, a numerical simulation was used to study the dynamic response of the vertical stress and impact-induced vibration energy in the surrounding rocks. By doing so, the dissipation of the impact stress waves within the ABDZ of the surrounding rocks was revealed. As demonstrated in the field application, the establishment of the ABDZ in the surrounding rocks reduced the effect of the impact-induced vibration energy on the anchorage support system of the roadway.

Effects of wave energy converters on the surrounding soft-bottom macrofauna (west coast of Sweden).

Science.gov (United States)

Langhamer, O

2010-06-01

Offshore wave energy conversion is expected to develop, thus contributing to an increase in submerged constructions on the seabed. An essential concern related to the deployment of wave energy converters (WECs) is their possible impact on the surrounding soft-bottom habitats. In this study, the macrofaunal assemblages in the seabed around the wave energy converters in the Lysekil research site on the Swedish west coast and a neighbouring reference site were examined yearly during a period of 5 years (2004-2008). Macrobenthic communities living in the WECs' surrounding seabed were mainly composed by organisms typical for the area and depth off the Swedish west coast. At both sites the number of individuals, number of species and biodiversity were low, and were mostly small, juvenile organisms. The species assemblages during the first years of sampling were significantly different between the Lysekil research site and the nearby reference site with higher species abundance in the research site. The high contribution to dissimilarities was mostly due to polychaetes. Sparse macrofaunal densities can be explained by strong hydrodynamic forces and/or earlier trawling. WECs may alter the surrounding seabed with an accumulation of organic matter inside the research area. This indicates that the deployment of WECs in the Lysekil research site tends to have rather minor direct ecological impacts on the surrounding benthic community relative to the natural high variances.

Weak surround suppression of the attentional focus characterizes visual selection in the ventral stream in autism

Directory of Open Access Journals (Sweden)

Luca Ronconi

Full Text Available Neurophysiological findings in the typical population demonstrate that spatial scrutiny for visual selection determines a center-surround profile of the attentional focus, which is the result of recurrent processing in the visual system. Individuals with autism spectrum disorder (ASD manifest several anomalies in their visual selection, with strengths in detail-oriented tasks, but also difficulties in distractor inhibition tasks. Here, we asked whether contradictory aspects of perception in ASD might be due to a different center-surround profile of their attentional focus. In two experiments, we tested two independent samples of children with ASD, comparing them with typically developing (TD peers. In Experiment 1, we used a psychophysical task that mapped the entire spatial profile of the attentional focus. In Experiment 2, we used dense-array electroencephalography (EEG to explore its neurophysiological underpinnings. Experiment 1 results showed that the suppression, surrounding the attentional focus, was markedly reduced in children with ASD. Experiment 2 showed that the center-surround profile in TD children resulted in a modulation of the posterior N2 ERP component, with cortical sources in the lateral-occipital and medial/inferior temporal areas. In contrast, children with ASD did not show modulation of the N2 and related activations in the ventral visual stream. Furthermore, behavioural and neurophysiological measures of weaker suppression predicted more severe autistic symptomatology. The present findings, showing an altered center-surround profile during attentional selection, give an important insight to understand superior visual processing in autism as well as the experiencing of sensory overload. Keywords: EEG, Source analysis, Ventral visual stream, Perception, Rehabilitation

The importance of hydration thermodynamics in fragment-to-lead optimization.

Science.gov (United States)

Ichihara, Osamu; Shimada, Yuzo; Yoshidome, Daisuke

2014-12-01

Using a computational approach to assess changes in solvation thermodynamics upon ligand binding, we investigated the effects of water molecules on the binding energetics of over 20 fragment hits and their corresponding optimized lead compounds. Binding activity and X-ray crystallographic data of published fragment-to-lead optimization studies from various therapeutically relevant targets were studied. The analysis reveals a distinct difference between the thermodynamic profile of water molecules displaced by fragment hits and those displaced by the corresponding optimized lead compounds. Specifically, fragment hits tend to displace water molecules with notably unfavorable excess entropies-configurationally constrained water molecules-relative to those displaced by the newly added moieties of the lead compound during the course of fragment-to-lead optimization. Herein we describe the details of this analysis with the goal of providing practical guidelines for exploiting thermodynamic signatures of binding site water molecules in the context of fragment-to-lead optimization. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lead cooled heterogeneous accelerator driven molten-fluoride blanket for incineration of long-lived radioactive wastes

International Nuclear Information System (INIS)

Lopatkin, A.V.; Matyushechkin, V.M.; Tretyakov, I.T.; Blagovolin, P.P.; Kazaritsky, V.D.

1997-01-01

This paper presents a tentative design description and evaluation of the basic parameters of a lead cooled heterogeneous accelerator driven molten fluoride blanket. The proton beam of a 1 GeV accelerator strikes the blanket from below and generates spallation neutrons in the flow of lead, which serves as a target. These neutrons leave the target zone and get into a heterogeneous blanket with separated volumes of molten salts and lead. Fissile materials are dissolved in the salt. On getting into the molten salt volume the neutrons cause fission (transmutation) of the actinides, the produced heat being removed by circulation of molten lead. Two versions of the blanket design are examined. The first version: molten salt circulates in the fuel channels, while lead cools the channels flowing through the interchannel space (the salt channel design). The second version: it is lead that circulates in the channels, while molten salt takes up the interchannel space (the lead channel design). A preliminary blanket design study showed that both blanket designs possess a potential for improving performance. At present time the blanket design, mentioned above as the salt channel design, seems to be more promising. 1 ref., 2 figs., 2 tabs

Organic matter recycling during a mucilage event and its influence on the surrounding environment (Ligurian Sea, NW Mediterranean)

Science.gov (United States)

Misic, Cristina; Schiaparelli, Stefano; Harriague, Anabella Covazzi

2011-04-01

The development of benthic mucilage in the Marine Protected Area of Portofino (Ligurian Sea) during the summer of 2009 was studied to verify the influence of this event on the surrounding environment (seawater and soft-bottom). The calm meteorological and sea conditions at the beginning of the time frame under consideration caused the thermal stratification of the water column. This stratification was one of the driving factors influencing the development of the mucilage, which developed on a large boulder surface above the pycnocline. Mucilage was progressively detached from the boulder surface by hydrodynamism, together with macroalgae, and sank onto the sediment below the thermocline. Increased surface-water movements, caused by meteorological forcing during the study period, influenced the aggregation-disaggregation of mucilage flocks above the thermocline, leading to increased dissolved oxygen concentrations and enhanced production and turnover of the organic matter (OM). Mixing with the adjacent seawater led to the fertilisation of the surrounding environment with potentially labile OM and inorganic phosphorus, which caused increases in the hydrolytic enzymatic activity. Conversely, below the thermocline, the sunken mucilage and algae aggregates supported a heterotrophic consumption system. Dissolved oxygen concentrations were lower than those recorded in the mucilage lying above the thermocline, making more carbohydrates than proteins and labile phosphorus available. Despite the slow oxygenation of this mucilage, it contributed to the food supply for the soft-bottom macrofauna, which showed an increase in density, diversity and biomass during the study. These results suggest that the development and fate of the mucilage, as well as its interactions with the surrounding environment, were principally regulated by physical features. In the oligotrophic coastal area of the Ligurian Sea, certain compartments of the ecosystem were able to promptly respond and take

Externally guided target for inertial fusion

International Nuclear Information System (INIS)

Martinez-Val, J.M.; Piera, M.

1996-01-01

A totally new concept is proposed to reach fusion conditions by externally guided inertial confinement. The acceleration and compression of the fuel is guided by a cannon-like external duct with a conical section ending in a small-size cavity around the central point of the tube. The fuel pellets coming from each cannon mouth collide in the central cavity where the implosion and final compression of the fuel take place. Both the tube material density and its areal density must be much higher than the initial density and areal density of the fuel. The external tube will explode into pieces as a consequence of the inner pressures achieved after the fuel central collision. If the collision is suitably driven, a fusion burst can take place before the tube disassembly. because of the features of the central collision needed to trigger ignition, this concept could be considered as tamped impact fusion. Both the fusion products and the debris from the guide tube are caught by a liquid-lithium curtain surrounding the target. Only two driving beams are necessary. The system can be applied to any type of driver and could use a solid pellet at room temperature as the initial target. 54 refs., 24 figs., 1 tab

Ultrastructural relationships between the receptor nerve fiber and surrounding lamellae in Krause end-bulbs.

Science.gov (United States)

Spassova, I

1981-01-01

The ultrastructural relationship between the receptor nerve fiber and the surrounding lamellae in Krause end-bulbs was discussed. Many sites of specialized junctions of symmetrical or asymmetrical type along the receptor nerve fiber and the surrounding lamellae were found. In addition, in close vicinity to them, spine-like digitations of the receptor nerve fiber, filled mainly with small clear vesicles, were observed. Mitochondrion-like cholinesterase-positive structures bulging in some cytoplasmic lamellae were also found. It is suggested that a functional link might exist between the specialized junctions, digitations and mitochrondrion-like structures in the transformation of external mechanical stimuli into nerve impulses.

Opportunity's Surroundings After Sol 1820 Drive (Polar)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view is presented as a polar projection with geometric seam correction. North is at the top. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

Opportunity's Surroundings After Sol 1820 Drive (Vertical)

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

VHF/UHF imagery and RCS measurements of ground targets in forested terrain

Science.gov (United States)

Gatesman, Andrew J.; Beaudoin, Christopher J.; Giles, Robert H.; Waldman, Jerry; Nixon, William E.

2002-08-01

The monostatic VV and HH-polarized radar signatures of several targets and trees have been measured at foliage penetration frequencies (VHF/UHF) by using 1/35th scale models and an indoor radar range operating at X-band. An array of high-fidelity scale model ground vehicles and test objects as well as scaled ground terrain and trees have been fabricated for the study. Radar measurement accuracy has been confirmed by comparing the signature of a test object with a method of moments radar cross section prediction code. In addition to acquiring signatures of targets located on a smooth, dielectric ground plane, data have also been acquired with targets located in simulated wooded terrain that included scaled tree trunks and tree branches. In order to assure the correct backscattering behavior, all dielectric properties of live tree wood and moist soil were scaled properly to match the complex dielectric constant of the full-scale materials. The impact of the surrounding tree clutter on the VHF/UHF radar signatures of ground vehicles was accessed. Data were processed into high-resolution, polar-formatted ISAR imagery and signature comparisons are made between targets in open-field and forested scenarios.

S-layer fusion protein as a tool functionalizing emulsomes and CurcuEmulsomes for antibody binding and targeting.

Science.gov (United States)

Ucisik, Mehmet H; Küpcü, Seta; Breitwieser, Andreas; Gelbmann, Nicola; Schuster, Bernhard; Sleytr, Uwe B

2015-04-01

Selective targeting of tumor cells by nanoparticle-based drug delivery systems is highly desirable because it maximizes the drug concentration at the desired target while simultaneously protecting the surrounding healthy tissues. Here, we show a design for smart nanocarriers based on a biomimetic approach that utilizes the building principle of virus envelope structures. Emulsomes and CurcuEmulsomes comprising a tripalmitin solid core surrounded by phospholipid layers are modified by S-layer proteins that self-assemble into a two-dimensional array to form a surface layer. One significant advantage of this nanoformulation is that it increases the solubility of the lipophilic anti-cancer agent curcumin in the CurcuEmulsomes by a factor of 2700. In order to make the emulsomes specific for IgG, the S-layer protein is fused with two protein G domains. This S-layer fusion protein preserves its recrystallization characteristics, forming an ordered surface layer (square lattice with 13 nm unit-by-unit distance). The GG domains are presented in a predicted orientation and exhibit a selective binding affinity for IgG. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Urban land use in Natura 2000 surrounding areas in Vilnius Region, Lithuania.

Science.gov (United States)

Pereira, Paulo; Misiūnė, Ieva; Depellegrin, Daniel

2015-04-01

Urban development is one of the major causes of land degradation and pressure on protected areas. (Hansen and DeFries, 2007; Salvati and Sabbi, 2011). The urban areas in the fringe of the protected areas are a source of pollutants considered a negative disturbance to the ecosystems services and biodiversity within the protected areas. The distance between urban and protected areas is decreasing and in the future it is estimated that 88% of the world protected areas will be affected by urban growth (McDonald et al., 2008). The surrounding or buffer areas, are lands adjacent to the Natura 2000 territories, which aim to reduce the human influence within the protected areas. Presently there is no common definition of buffer area it is not clear among stakeholders (Van Dasselaar, 2013). The objective of this work is to identify the urban land use in the Natura 2000 areas in Vilnius region, Lithuania. Data from Natura 2000 areas and urban land use (Corine Land Cover 2006) in Vilnius region were collected in the European Environmental Agency website (http://www.eea.europa.eu/). In the surroundings of each Natura 2000 site, we identified the urban land use at the distances of 500, 1000 and 1500 m. The Natura 2000 sites and the urban areas occupied a total of 13.2% and 3.4% of Vilnius region, respectively. However, the urban areas are very dispersed in the territory, especially in the surroundings of Vilnius, which since the end of the XX century is growing (Pereira et al., 2014). This can represent a major threat to Natura 2000 areas ecosystem services quality and biodiversity. Overall, urban areas occupied approximately 50 km2, in the buffer area of 500 m, 95 km2 in buffer area of 1000 m and 131 km2 in the buffer area of 1500 km2. This shows that Natura 2000 surrounding areas in Vilnius region are subjected to a high urban pressure. This is especially evident in the Vilnius city and is a consequence of the uncontrolled urban development. The lack of a clear legislation

Prioritizing multiple therapeutic targets in parallel using automated DNA-encoded library screening

Science.gov (United States)

Machutta, Carl A.; Kollmann, Christopher S.; Lind, Kenneth E.; Bai, Xiaopeng; Chan, Pan F.; Huang, Jianzhong; Ballell, Lluis; Belyanskaya, Svetlana; Besra, Gurdyal S.; Barros-Aguirre, David; Bates, Robert H.; Centrella, Paolo A.; Chang, Sandy S.; Chai, Jing; Choudhry, Anthony E.; Coffin, Aaron; Davie, Christopher P.; Deng, Hongfeng; Deng, Jianghe; Ding, Yun; Dodson, Jason W.; Fosbenner, David T.; Gao, Enoch N.; Graham, Taylor L.; Graybill, Todd L.; Ingraham, Karen; Johnson, Walter P.; King, Bryan W.; Kwiatkowski, Christopher R.; Lelièvre, Joël; Li, Yue; Liu, Xiaorong; Lu, Quinn; Lehr, Ruth; Mendoza-Losana, Alfonso; Martin, John; McCloskey, Lynn; McCormick, Patti; O'Keefe, Heather P.; O'Keeffe, Thomas; Pao, Christina; Phelps, Christopher B.; Qi, Hongwei; Rafferty, Keith; Scavello, Genaro S.; Steiginga, Matt S.; Sundersingh, Flora S.; Sweitzer, Sharon M.; Szewczuk, Lawrence M.; Taylor, Amy; Toh, May Fern; Wang, Juan; Wang, Minghui; Wilkins, Devan J.; Xia, Bing; Yao, Gang; Zhang, Jean; Zhou, Jingye; Donahue, Christine P.; Messer, Jeffrey A.; Holmes, David; Arico-Muendel, Christopher C.; Pope, Andrew J.; Gross, Jeffrey W.; Evindar, Ghotas

2017-07-01

The identification and prioritization of chemically tractable therapeutic targets is a significant challenge in the discovery of new medicines. We have developed a novel method that rapidly screens multiple proteins in parallel using DNA-encoded library technology (ELT). Initial efforts were focused on the efficient discovery of antibacterial leads against 119 targets from Acinetobacter baumannii and Staphylococcus aureus. The success of this effort led to the hypothesis that the relative number of ELT binders alone could be used to assess the ligandability of large sets of proteins. This concept was further explored by screening 42 targets from Mycobacterium tuberculosis. Active chemical series for six targets from our initial effort as well as three chemotypes for DHFR from M. tuberculosis are reported. The findings demonstrate that parallel ELT selections can be used to assess ligandability and highlight opportunities for successful lead and tool discovery.

Inertial confinement fusion target

International Nuclear Information System (INIS)

Bourdier, A.

2001-12-01

A simple, zero-dimensional model describing the temporal behaviour of an imploding-shell, magnetized fuel inertial confinement fusion target is formulated. The addition of a magnetic field to the fuel reduces thermal conduction losses. As a consequence, it might lead to high gains and reduce the driver requirements. This beneficial effect of the magnetic field on thermonuclear gains is confirmed qualitatively by the zero-dimensional model results. Still, the extent of the initial-condition space for which significant gains can occur is not, by far, as large as previously reported. One-dimensional CEA code simulations which confirm this results are also presented. Finally, we suggest to study the approach proposed by Hasegawa. In this scheme, the laser target is not imploded, and the life-time of the plasma can be very much increased. (author)

Spallation neutron source target design for radioactive waste transmutation

International Nuclear Information System (INIS)

Beard, C.A.

1992-01-01

The disposal of high-level radioactive waste has long been one of the most serious problems facing the nuclear industry. Transmutation of this waste through particle bombardment has been suggested numerous times as a possible method of enhancing the waste management process. Due to advances in accelerator technology, the feasibility of an accelerator based transmutation system has increased enough to allow serious investigation of this process. Therefore, in pursuit of this goal, an accelerator target was designed for use in an accelerator based transmutation system. The target design consists of an array of tantalum rods, cooled by liquid sodium, which are arranged in a cylindrical configuration 40 cm in diameter and 125 cm in height. Tantalum was chosen as the target material over tungsten, lead, bismuth, and a lead-bismuth alloy (55 w/o bismuth) due to a large neutron yield, low activation, low chemical toxicity, and the fact that it does not produce significant amounts of long-lived isotopes through spallation or activation. The target yields a neutron source of 29.7 neutrons/proton when exposed to a 1600 MeV proton beam, and is suitable for use with both thermal or fast spectrum transmutation systems

Targeting Wnt Pathways in Disease

Science.gov (United States)

Zimmerman, Zachary F.; Moon, Randall T.

2012-01-01

Wnt-mediated signal transduction pathways have long been recognized for their roles in regulating embryonic development, and have more recently been linked to cancer, neurologic diseases, inflammatory diseases, and disorders of endocrine function and bone metabolism in adults. Although therapies targeting Wnt signaling are attractive in theory, in practice it has been difficult to obtain specific therapeutics because many components of Wnt signaling pathways are also involved in other cellular processes, thereby reducing the specificity of candidate therapeutics. New technologies, and advances in understanding the mechanisms of Wnt signaling, have improved our understanding of the nuances of Wnt signaling and are leading to promising new strategies to target Wnt signaling pathways. PMID:23001988

Stabilization/solidification of battery debris ampersand lead impacted material at Schuylkill Metals, Plant City, Florida

International Nuclear Information System (INIS)

Anguiano, T.; Floyd, D.

1997-01-01

The Schuylkill Metals facility in Plant City Florida (SMPCI) operated as a battery recycling facility for approximately 13 years. During its operation, the facility disposed of battery components in surrounding wetland areas. In March of 1991 the U.S. EPA and SMPCI entered into a Consent Decree for the remediation of the SMPCI site using stabilization/solidification and on-site disposal. In November of 1994, ENTACT began remediation at the facility and to date has successfully stabilized/solidified over 228,000 tons of lead impacted battery components and lead impacted material. The ENTACT process reduces the size of the material to be treated to ensure that complete mixing of the phosphate/cement additive is achieved thereby promoting the chemical reactions of stabilization and solidification. ENTACT has met the following performance criteria for treated material at the SMPCI site: (1) Hydraulic Conductivity less than 1x10 -6 cm/s, (2) Unconfined Compressive Strength greater than 50 psi, (3) Lead, Cadmium, Arsenic, Chromium TCLP Leachability below hazardous levels

Induced radioactivity in the target station and decay tunnel from a 4MW proton beam

CERN Document Server

Agosteo, S; Otto, T; Silari, Marco

2003-01-01

An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. A first estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump has been performed by the Monte Carlo hadronic cascade code FLUKA. The aim is both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation. This paper discusses the first results of such calculations.

Electrically Induced Strain and Polarization Fatigue in Lead-Free Ceramics

Science.gov (United States)

Sommer, Daniel

Piezoelectric ceramics have traditionally been used in commercial applications such as actuators and sensors. By far the most popular piezoceramics currently in use are Pb(Zr,Ti)O3-based (PZT) ceramics. PZT ceramics are able to produce large strain and polarization with the application of an electric field, and this is due to the Morphotropic phase boundary (MPB). A MPB is associated with the boundary between tetragonal and rhombohedral perovskite phases. A disadvantage of PZT ceramics is that they contain ? 60 wt. % of lead. Since lead is toxic, this poses an environmental and health hazard because lead is released into the surroundings during fabrication and disposal. Because of this, there is a push to discover lead-free alternatives that have comparable properties to PZT but none of the health risks. One possibility is Bi 1/2(Na0.8K0.2)1/2Ti0.985 Ta0.015O3 (BNKT-1.5Ta). In addition to comparable electrical properties, any lead-free alternatives must have decent fatigue resistance to be useful for applications. This thesis focuses on the fatigue properties of BNKT-1.5Ta. The composition demonstrates high strain for a given applied electric field. To determine the fatigue resistance of BNKT-1.5Ta, data was gathered on how strain and polarization changed over number of cycles. Furthermore, fatigue tests at different temperatures were performed to ascertain if temperature affected fatigue life. X-ray diffraction (XRD) patterns and dielectric measurements were also collected to further examine any change in crystal structure and relative permittivity, respectively, before and after cycling.

Review of polarized ammonium target

International Nuclear Information System (INIS)

Matsuda, Tatsuo

1987-01-01

Recently, ammonia (NH 3 ) and deutron ammonia (ND 3 ), instead of conventional alcohol substances, have been used more frequently as a polarized target substance for experiments of polarization at high energy regions. This article reviews major features of the polarized (deutron) ammonia targets. The dynamic nuclear polarization (DNT) method is widely used in high energy polarization experiments. While only a low polarization degree of hydrogen nucleus of 1.7 percent can be obtained by the Brute force method, DNP can produce polarization as high as ∼ 90 percent (2.5 T, ∼ 200 mK). In 1979, ammonia was irradiated with radiations to form NH 2 free radicals, resulting in the achievement of a high polarization degree of greater than 90 percent (hydrogen). Since then, ammonia and deutron ammonia have increasingly been replacing alcohols including butanol. Irradiation of a target substance with radiations destroys the structure of the substance, leading to a decrease in polarization degree. However, ammonia produces unpaired electrons as a result of irradiation, allowing it to be highly resistant to radiation. This report also present some study results, including observations on effects of radiation on the polarization degree of a target, effects of annealing, and polarization of 14 N. A process for producing an ammonia target is also described. (Nogami, K.)

MRI of normal pituitary glands and their surrounding structures

International Nuclear Information System (INIS)

Sato, Yoshiyuki

1991-01-01

Normal MRI appearances of the pituitary glands and their surrounding structures were evaluated in 332 patients without sellar and parasellar diseases. The height of the pituitary gland was maximum at 10-19 years of age reflecting hormonal activity. The width of the pituitary gland decreased, while that of the cavernous sinus increased with aging. This is probably due to atherosclerotic change of the internal carotid artery. Females younger than 30 years of age tended to show a convex upper surface of the pituitary gland and the displacement of the pituitary stalk was common after 50 years of age. Almost all of the anterior lobe of the pituitary gland showed isointensity relative to the pons or cerebral cortex and the majority (85.1%) of the posterior lobe showed hyperintensity. However, the anterior lobe in 2 newborns showed hyperintensity similar to the normal posterior lobe in adults. The posterior lobe was located off the midline in 19.1% of the subjects. One case of pars intermedia cyst was discovered among 14 subjects who were administered Gd-DTPA. The dural membrane between the pituitary gland and cavernous sinus was recognizable only in 8.6% on the right side and 7.5% on the left side. Primary empty sella was identified in 4.5%. Knowledge of the above normal ranges and variations of the pituitary gland and its surrounding structures is important in diagnosing sellar and parasellar lesions. (author) 52 refs

Rockfalls in cliffs surrounding waterfall revealed by high-definition topographic measurements

Science.gov (United States)

Hayakawa, Y. S.; Obanawa, H.

2017-12-01

Bedrock rivers of volcanic terrain often comprise numerous knickpoints. Erosion of bedrock at knickpoints is an essential process of fluvial dissection of volcanic landforms, which also affects the deformations of surrounding slopes. However, short term (less than decadal) changes in bedrock landforms have often been limited to examine in a spatiotemporal framework. Here we use terrestrial laser scanning and SfM-MVS photogrammetry to detect recent annual changes in the morphology of cliffs surrounding a waterfall (Kegon Falls) on jointed andesite lava and conglomerates. The amount of bedrock deformation caused by small rockfalls and surface lowering are assessed in volume, which often appears in a relatively lower portion of the cliff. Such the changes are supposed to be affected by the enhanced supply of water and weathering following the latest major rockfall in 1986 which caused 8-m recession of the waterfall lip. The three-dimensional point cloud data is also utilized to construct a 3D model using cardboards, which is useful for understanding the topography and its changes of the waterfall as educational resources.

Enhancing proton acceleration by using composite targets

Energy Technology Data Exchange (ETDEWEB)

Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.

2015-07-10

Efficient laser ion acceleration requires high laser intensities, which can only be obtained by tightly focusing laser radiation. In the radiation pressure acceleration regime, where the tightly focused laser driver leads to the appearance of the fundamental limit for the maximum attainable ion energy, this limit corresponds to the laser pulse group velocity as well as to another limit connected with the transverse expansion of the accelerated foil and consequent onset of the foil transparency. These limits can be relaxed by using composite targets, consisting of a thin foil followed by a near critical density slab. Such targets provide guiding of a laser pulse inside a self-generated channel and background electrons, being snowplowed by the pulse, compensate for the transverse expansion. The use of composite targets results in a significant increase in maximum ion energy, compared to a single foil target case.

One-dimensional organic lead halide perovskites with efficient bluish white-light emission

Science.gov (United States)

Yuan, Zhao; Zhou, Chenkun; Tian, Yu; Shu, Yu; Messier, Joshua; Wang, Jamie C.; van de Burgt, Lambertus J.; Kountouriotis, Konstantinos; Xin, Yan; Holt, Ethan; Schanze, Kirk; Clark, Ronald; Siegrist, Theo; Ma, Biwu

2017-01-01

Organic-inorganic hybrid metal halide perovskites, an emerging class of solution processable photoactive materials, welcome a new member with a one-dimensional structure. Herein we report the synthesis, crystal structure and photophysical properties of one-dimensional organic lead bromide perovskites, C4N2H14PbBr4, in which the edge sharing octahedral lead bromide chains [PbBr4 2-]∞ are surrounded by the organic cations C4N2H14 2+ to form the bulk assembly of core-shell quantum wires. This unique one-dimensional structure enables strong quantum confinement with the formation of self-trapped excited states that give efficient bluish white-light emissions with photoluminescence quantum efficiencies of approximately 20% for the bulk single crystals and 12% for the microscale crystals. This work verifies once again that one-dimensional systems are favourable for exciton self-trapping to produce highly efficient below-gap broadband luminescence, and opens up a new route towards superior light emitters based on bulk quantum materials.

Effect of prepulse on fast electron lateral transport at the target surface irradiated by intense femtosecond laser pulses

International Nuclear Information System (INIS)

Lin, X. X.; Li, Y. T.; Liu, B. C.; Liu, F.; Du, F.; Wang, S. J.; Lu, X.; Chen, L. M.; Zhang, L.; Liu, X.; Wang, J.; Liu, F.; Liu, X. L.; Wang, Z. H.; Ma, J. L.; Wei, Z. Y.; Zhang, J.

2010-01-01

The effects of preplasma on lateral fast electron transport at front target surface, irradiated by ultraintense (>10 18 W/cm 2 ) laser pulses, are investigated by Kα imaging technique. A large annular Kα halo with a diameter of ∼560 μm surrounding a central spot is observed. A specially designed steplike target is used to identify the possible mechanisms. It is believed that the halos are mainly generated by the lateral diffusion of fast electrons due to the electrostatic and magnetic fields in the preplasma. This is illustrated by simulated electron trajectories using a numerical model.

Direct-driven target implosion in heavy ion fusion

International Nuclear Information System (INIS)

Noguchi, K.; Suzuki, T.; Kurosaki, T.; Barada, D.; Kawata, S.; Ma, Y. Y.; Ogoyski, A. I.

2016-01-01

In inertial confinement fusion, the driver beam illumination non-uniformity leads a degradation of fusion energy output. A fuel target alignment error would happen in a fusion reactor; the target alignment error induces heavy ion beam illumination non-uniformity on a target. On the other hand, heavy ion beam accelerator provides a capability to oscillate a beam axis with a high frequency. The wobbling beams may provide a new method to reduce or smooth the beam illumination non-uniformity. First we study the effect of driver irradiation non-uniformity induced by the target alignment error (dz) on the target implosion. We found that dz should be less than about 130 μm for a sufficient fusion energy output. We also optimize the wobbling scheme. The spiral wobbling heavy ion beams would provide a promissing scheme to the uniform beam illumination. (paper)

Preliminary analysis of a target factory for laser fusion